spinal anesthesia and femoral fractures

www.wjpps.com │ Vol 9, Issue 11, 2020. │ ISO 9001:2015 Certified Journal │

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Hameed et al. World Journal of Pharmacy and Pharmaceutical Sciences

SPINAL ANESTHESIA AND FEMORAL FRACTURES

* Dr. Sirar Qahtan Hameed, Dr. Seemaa Jasim Abd, Dr. Nashwan Kahtan Jabbar

1MBChB

High Diploma in Anesthesia & Intensive Care.

2MBChB

High Diploma in Anesthesia & Intensive Care.

3M.B.Ch.B. DA AND ICU.

INTRODUCTION

„Cocainisation of the spinal cord‟ was first described by August Bier in

18991. The technique has been refined since that time and has evolved

into the modern concept of intrathecal, spinal or subarachnoid block

(SAB)‟. Whilst growing in popularity, SAB has largely been reserved

for inpatient surgery. In contrast, anaesthetists in other parts of the

world have successfully used the technique for patients undergoing

ambulatory surgery.

The face of day surgery in the UK is changing. The population is

ageing, obesity is more prevalent and patients present with increasingly complex

comorbidity. Many patients are excluded from Day Surgery Units (DSUs) on the grounds of

risk associated with general anaesthesia (GA). DSUs are under pressure to relax entry criteria

in order to relieve demand on inpatient beds. For some of these patients, SAB may be a safer

alternative. If so, they may be eligible for DSU. Moreover, procedures previously considered

as „inpatient only‟ (e.g. prostatectomy and female incontinence surgery) are well suited to

SAB in the DSU.

We recently surveyed 27 DSUs in the UK. Eleven units never used SAB, 15 used it

occasionally and only 1 unit performed SAB routinely. We believe that wider use of SAB in

day surgery is advantageous to the patient and contributes to efficient use of limited

healthcare resources.

WORLD JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES

SJIF Impact Factor 7.632

Volume 9, Issue 11, 358-387 Research Article ISSN 2278 – 4357

*Corresponding Author

Dr. Sirar Qahtan Hameed

MBChB, High Diploma in

Anesthesia & Intensive Care.

Article Received on

14 September 2020,

Revised on 05 October 2020,

Accepted on 26 October 2020

DOI: 10.20959/wjpps202011-17597


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The aim of this publication is to share the lessons learned during the successful introduction

of SAB to a DSU in the UK and to summarise the current literature.

Anaesthetic, surgical and nursing perspectives are included as the authors consider a

multidisciplinary approach is the key to success.

METHODS

Study Design

This retrospective study reviewed data of all 20,106 patients enrolled in the Trauma Registry

System from 1 January 2015 to 31 December 2019 (Figure 1). The inclusion criteria were as

follows: (1) adult patients aged _20 years and (2) hospitalization for the treatment of trauma

with femoral fracture diagnoses. Patients with incomplete registered data were excluded.

According to the World Health Organization‟s definition [23,24], these trauma patients were

categorized as obese (BMI of _30 kg/m2), overweight (BMI of <30 but _25 kg/m2), normal

weight (BMI of <25 but _18.5 kg/m2), and underweight (BMI of <18.5 kg/m2). The retrieved

patient data included age; sex; trauma mechanisms (fall from standing height, motorcycle

accident, bicycle accident, motor vehicle accident, struck by/against an object, and pedestrian

accident); BMI calculated as weight (kg)/height (m)2; Abbreviated Injury Scale (AIS) score

of each body part; Injury Severity Score (ISS); and femoral fracture sites categorized

according to their location as proximal femoral.

RESULTS

Characteristics of the Patients with Femoral Fracture

A total of 2647 patients with 2,760 femoral fractures were included in this study (Table 1),

with 960 (34.8%) proximal femoral type A, 997 (36.1%) proximal femoral type B, 42 (1.5%)

proximal femoral type C, 443 (16.1%) femoral shaft, and 318 (11.5%) distal femoral

fractures. Among these patients, 1,153 (24.3%) and 1,494 (56.4%) were men and women,

respectively, and 202 (7.6%) were obese, 643 (24.3%) were overweight, 1552 (58.6%) had

normal weight, and 250 (9.4%) were underweight. Falling was the leading cause of femoral

fractures (64.9%), followed by motorcycle (26.1%) and bicycle (4.2%) accidents. Associated

injuries to the head/neck (8.7%), face (5.2%), thorax (4.9%), and abdomen (2.9%) were also

found in these patients. With a median ISS of 9, a total of 2489 (94.0%), 81 (3.1%), and 77

(2.9%) patients had an ISS of <16, 16–24, and _25, respectively.


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Why consider Spinal Anaesthesia for Day Surgery?

• Extends access to patients who would normally be excluded for GA (e.g. because of

obesity or cardiorespiratory disease).

• Low post-operative morbidity

• High patient satisfaction rates

• Routinely practised in other countries – evidence based.

Anaesthetist Education

All anaesthetists are familiar with the technique of SAB from their inpatient work. However,

we have found that some colleagues may need to be introduced to the concept of low-dose

SAB. A small dose of local anaesthetic combined with fentanyl alters the quality of the spinal

block and the side effect profile.

The following misconceptions regarding perioperative morbidity may need to be challenged:

• Significantly prolonged time to discharge when compared to GA

• High incidence of urinary retention

• Frequent Post-Dural Puncture Headache (PDPH)

• Occasional Transient Neurological Syndrome (TNS)

• Possibility of respiratory depression

Anaesthetists who are concerned about the post-discharge complications of SAB can be

reassured from the current evidence that morbidity is low and that a system for routine

follow-up will be put in place.

Technique

The technique of administering spinal anesthesia can be described as the “4 P‟s”: preparation,

position, projection, and puncture.

Preparation

Preparation of equipment/medications is the first step. It is important to think ahead.

Discuss with the patient options for anesthesia. Explain risk and benefits. Inform the patient

about the following: despite sedation the patient may remember portions of the surgical

procedure but shouldn‟t feel discomfort, the patient may feel pressure sensations but no pain,

the patient will not be able to move their legs, and the approximate length of time that the

block will last.


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Choose an appropriate local anesthetic. What local anesthetic should be used? Should it be a

hypobaric, hyperbaric, or isobaric preparation? The duration of blockade should match the

proposed length of the surgical procedure. Consider additives at this point. The addition of

epinephrine may be considered to prolong and/or improve the quality of the block.

Choose the appropriate spinal needle. Spinal needles are available in a variety of sizes (from

16-30 gauge), lengths, bevel types, and tip designs. Commonly, a 22 gauge needle is used in

patients that are 50 years and older. A 25-27 gauge needle is used in patients that are less than

50 years of age. A smaller needle is used in the younger patient to decrease the incidence of

post dural puncture headache. The removable stylet occludes the lumen and avoids tracking

tissue into the subarachnoid space. Needles are cutting or blunt tiped. The Quincke needle is

an example of a cutting needle, with the opening at the end of the needle.

+

++

This may also lead to failed blocks since the opening may be partially within the

subarachnoid space, leading to a partial dose of local anesthetic being administered.

Prepackaged spinal kits are normally used and can be custom made.

If a prepackaged spinal kit is not available, assemble the following equipment:

sterile towels.

sterile gloves.

sterile spinal needle.

an introducer needle if using a small gauge needle (this can be a sterile 19 gauge

disposable needle).

sterile filter needle to draw up medications.

sterile 5 ml syringe for the spinal solution.

sterile 2 ml syringe with a small gauge needle to localize the skin prior initiation of the

spinal anesthetic.


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antiseptics for the skin (such as betadine, chlorhexidine, methyl alcohol)

sterile gauze for skin cleansing and to wipe off excess antiseptic at needle puncture site

single use preservative free local anesthetic ampoule. Local anesthetics from multi dose

vials or those that contain preservatives should NEVER be used for spinal anesthesia. Ensure

that the local anesthetic preparation is made specifically for spinal anesthesia.

Prior to initiating a spinal block, carefully wash your hands.

The patient should be attached to standard monitors including ECG, blood pressure, and

pulse oximetry. Record an initial set of vital signs.

Preload the patient with 1-1.5 liters of crystalloid intravenous solution.

At any point during the administration of spinal anesthesia, if sterility is questioned or

contamination of equipment occurs, stop, and start over with sterile equipment.

Positioning

Proper positioning is essential for a successful block. Proper positioning can be difficult for

several reasons.

1. Your assistant may not understand how the patient should be positioned or the rationale

behind positioning.

2. The patient may not understand your instructions.

3. Sedation may make the patient unable to cooperate or follow directions.

There are three positions used for the administration of spinal anesthesia: lateral decubitus,

sitting, and prone.

Lateral Decubitus

Allows the anesthesia provider to administer more sedation- less dependence on an assistant

for positioning. (Never over sedate a patient).

The patient is positioned with their back parallel with the side of the OR table. Thighs are

flexed up, and neck is flexed forward (fetal position).

Patient should be positioned to take advantage of the baricity of the spinal local anesthetic.


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Sitting

Used for anesthesia of the lumbar and sacral levels (urological, perineal). Higher levels of

anesthesia can be obtained if an appropriate dose of local anesthetic is administered, and the

patient is quickly positioned to maximize the spread of local anesthetic.

Identify anatomical landmarks. This may be a challenge in the obese or those with abnormal

anatomical curvatures of the spine.

Place the patients feet on a stool, have the patient sit up straight, head flexed, arms hugging a

pillow, or on a table in front of them. Make sure the patient does not simply lean forward. A

number of descriptions may help the patient understand how they should position themselves.

For example, “please arch your back to resemble the letter C; or arch your back like a mad

cat”. This will maximize the “opening” of the vertebral interspaces.

For a lower lumbar/sacral block (i.e. saddle block), leave the patient sitting for 5 minutes

before assuming a supine position.

Prone


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The prone position is used when the patient will be in this position for the surgical procedure

(i.e. rectal, perineal, lumbar procedures).

Hypobaric local anesthetics are administered

Patient positions self, lumbar lordosis should be minimized, a paramedian approach is often

used.

Projection and Puncture

There are two approaches to accessing the subarachnoid space: the paramedian and midline

approach.

Midline Approach

The midline approach affords the practitioner two advantages. Anatomic projection is only in

2 planes, making visualization of the intended trajectory and anatomical structures more

apparent. The midline provides a relatively avascular plane. It is important to have the patient

sitting up straight, not slumping to the side, to minimize lumbar lordosis, and maximize the

space between the spinous processes. By proper positioning you should have access to L2-

L3, L3-L4, L4-L5, and L5-S1. Identify the top of the iliac crest. Tuffier‟s line generally

corresponds with the 4th lumbar vertebrae.

“Tuffier’s” line is a line drawn across the iliac crest that crosses the body of L4 or L4-

L5 interspace. This is a helpful landmark for the placement of spinal or epidural

anesthetics.

Palpation in the midline should help to identify the interspinous ligament. The extent of the

space is noted by palpating the cephalad and caudad spine. The midline is noted by moving

your fingers from medial to lateral.

Wash hands, put on sterile gloves, use sterile technique.

Prepare the tray in a sterile fashion. An assistant may help with opening, in sterile fashion,

specific items. Prepare the back with an antiseptic. Start at the area of intended injection and

move out. This is done three times.

Place a skin wheal of local anesthetic at the intended spinous interspace. Smaller gauge

needles will require an introducer to stabilize the needle. Place the introducer firmly into the

interspinous ligament Anatomical structures that will be transversed include skin,


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subcutaneous fat, supraspinous ligament, interspinous ligament, ligamentum flavum, epidural

space, and dura.

Grasp the introducer with one hand and hold the spinal needle like a dart/pencil. Cutting

needles should be inserted with the bevel parallel to the longitudinal fibers of the dura. This

helps reduce cutting fibers and enhances tactile sensation as anatomical structures are

crossed.

Control the needle carefully. Be prepared for unanticipated movement of the patient.

As the ligamentum flavum and dura are transversed, a change in resistance is noted. Some

will describe this as a “pop”; however, it may be a decrease in pressure or a loss of resistance.

Once in the subarachnoid space, remove the stylet and CSF should appear. If CSF does not

appear, rotate the needle 90 degrees until it appears. If no CSF appears then the stylet should

be replaced. With smaller gauged needles it may take 20-30 seconds for CSF to appear.

Assess the needle position. Is it at an appropriate depth? Is it midline or is its trajectory off

the midline? Being off the midline is one of the most common reasons that CSF does not

come back. If off the midline, remove the needle and start over.

If blood returns from the needle, wait to see if it clears. If it does not clear, reassess needle

position. If the needle is midline, not lateral, it may be in an epidural vein. Advance the

needle slightly further to transverse the dura. If the needle is not midline, remove it and start

over.

If the patient complains of a sharp pain in the hips or legs while inserting the needle,

immediately remove the needle and reassess the approach. When the needle is not midline it

is not uncommon to encounter a nerve root. Before starting again make sure that the pain has

stopped.

If bone is encountered, reassess the patient‟s position and ensure the needle is midline. If

bone is contacted early, the needle may be contacting the spinous process. Move the needle

slightly caudad (A). If bone is contacted late, the needle may be contacting the lamina of the

vertebrae. Move the needle slightly cephalad (B). Moving down an interspace may increase

the chance of success since the intervertebral spaces will be larger (C).


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After unsuccessful attempts, consider converting to a general anesthetic. The more attempts,

the more trauma, increasing the risk of a spinal/epidural hematoma.

Once CSF returns, steady the needle with the dorsum of the non dominant hand against the

patients back. Attach the syringe with the intended spinal anesthetic. Gently aspirate some

CSF into the syringe. If a hyperbaric technique is being used, a “swirling” in the solution will

be noted due to the dextrose content. Aspiration with an isobaric technique will yield

additional CSF fluid into the syringe. The cerebral spinal fluid should be clear. If blood is

returned with aspiration, replace the stylet and start over.

Inject the local anesthetic at a rate of 0.2 ml per second. After injection aspirate 0.2 ml of

CSF to confirm that the needle remains in the subarachnoid space. If the patient complains of

pain during injection, stop immediately. Redirect the needle away from the side of pain and

into the midline.

Place the patient in the appropriate position for the procedure and baricity of the spinal

anesthetic solution.

Paramedian Approach

The advantage of the paramedian approach is a larger target. By placing the needle laterally,

the anatomical limitation of the spinous process is avoided. The most common error when

attempting this technique is being too far from the midline, which makes encountering the

vertebral lamina more likely.

Palpate the vertebral process and identify the caudad tip. Move 1 cm down and 1 cm laterally.

Prepare the back with an antiseptic solution. Place a skin wheal of local anesthetic at the

identified area of needle insertion. A longer needle is often required to infiltrate the tissue.

Insert the introducer and/or spinal needle 10-15 degrees off the sagittal plane. At this point

the most common error is inserting the needle too far cephalad, which results in encountering

the lamina of the vertebral body. If bone is contacted, redirect the needle a little further

caudad.

It may be possible to feel the characteristic change in resistance or loss of resistance. With a

lateral approach the needle is inserted further than with the midline approach.

Once CSF is obtained, continue in the same manner as the midline approach.


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Monitoring

After successful placement, the patient should be monitored continuously for block

progression and complications. The patient‟s blood pressure should be taken every 3 minutes

initially, more frequently if needed. The patient should be monitored for the following:

Block progression- ensure that the block is adequate for the surgical procedure and it does not

progress too high.

Hypotension- Treat aggressively, if blood pressure decreases by 20% or more from baseline

Bradycardia- Treat aggressively, it may progress to cardiac arrest

Numbness of the arms and hands- may indicate that the block is too high

Problems with breathing- may indicate that the block is too high

Changes in the level of consciousness

An in-depth discussion of the complications of neuraxial complications have been discussed

earlier.

Obstetric Care

Spinal anesthesia is generally preferred over a general anesthetic in the obstetric population,

as long as not contraindicated. The dose of local anesthetic is often reduced up to 1/3rd due to

changes in the intra-abdominal pressure and effects of hormones which increase sensitivity.

Postoperative Care

Patient‟s recovering from a spinal anesthetic should receive the same vigilant monitoring as

the patient recovering from a general anesthetic. In addition, the patient should be assessed

for block regression. The patient with a spinal is more likely to experience hypotension in the

postoperative period. Treatment includes a Trendelenburg position, additional intravenous

fluids, oxygen, and vasopressors as needed. Urinary retention should be assessed in patients

that do not have a urinary catheter. The patient should not be discharged from the recovery

area until vital signs are stable and the spinal block is regressing. The patient should remain

in bed until full sensory and motor function has returned. The first time a patient is

ambulated, a nurse should assist the patient to ensure full function has returned.

INTRA-OPERATIVE PROBLEMS

Block quality

On rare occasions, low-dose SAB may fail completely and the patient will have no

demonstrable block. In this situation, it is necessary to either repeat the block or convert to a

GA. More commonly, especially when the bupivacaine dose is minimal, a block may be


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present but inadequate. It may then be necessary to supplement the technique. It is very

reassuring for anaesthetists to know that the addition of small doses of intravenous opioids,

ketamine, or midazolam can transform an inadequate low-dose SAB into a perfectly

acceptable one without the need for conversion to general anaesthesia. Local anaesthetic

infiltration at the site of operation, or in the form of a nerve block (e.g. ilioinguinal block) can

be very helpful. In our series of 279 patients receiving 5mg bupivacaine plus 10mcg fentanyl

for a variety of day case procedures, we reported an absolute failure rate of 0.7%, these

requiring conversion to GA. Meanwhile, 7.9% of patients reported either mild pain or

discomfort, and some of these required supplementation.[2]

Block quality is also relevant to the surgeon. Low dose techniques block sensory nerves in

preference to motor ones. This effect, sometimes called „selective spinal anaesthesia‟ tends to

preserve muscle tone and power in the legs. Fortunately, absence of muscular relaxation does

not seem to be an obstacle to successful surgery. Like their anaesthetist colleagues, surgeons

need to adjust their expectations of the effects of spinal anaesthesia in the context of day

surgery.

Hypotension

Low-dose SAB is generally associated with very little hypotension. For practical purposes,

significant hypotension can be defined as a fall in blood pressure necessitating intervention

(e.g. extra intravenous fluids or vasoconstrictors). Using this definition, we reported a 2.5%

incidence of significant hypotension when using bupivacaine 5mg with fentanyl 10mcg2. We

therefore suggest that this combination can be used safely in day surgery patients with

significant cardiovascular disease.

Pruritus

We reported an incidence of pruritus of 9% when intrathecal fentanyl was used.

This problem was limited to the immediate perioperative period.

Post dural-puncture headache (PDPH)

PDPH characteristically presents as an occipito-frontal headache, which is exacerbated by

adopting an upright posture and relieved by lying supine. Young patients and women are

particularly susceptible. It is worth noting that PDPH is both less likely and less severe after

dural puncture with a pencil-point rather than a cutting needle.


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Despond et al 14 found an incidence of 20.4% among women and 5.5% among men under 45

years having SAB for day case surgery using a Whitacre 27G needle.

However, most cases were mild and only 1 patient (0.5%) required an epidural blood patch

(EBP). In our series of 4002, we reported 4 patients, all female, who required EBP. These

studies suggest that the incidence of PDPH requiring EBP in ambulant patients is of the order

of 0.5 – 1% when small pencil-point needles are used.

PDPH can be debilitating and rarely may lead to significant complications and so there

should be a system for referring affected patients to the anaesthetic department.

The patient must then be followed up until the symptoms have been treated or have resolved

spontaneously. Readmission for assessment of the headache and EBP may be necessary.

Transient neurologic syndrome (TNS)

TNS, also sometimes called transient radicular irritation, is a syndrome characterised by

transient but mild to severe pain in the lower back, buttocks or legs.

Typically the pain starts within 24 hours of the SAB, lasts for less than 2 days and is

amenable to oral analgesia. The main risk factor for the development of TNS is the use of

lignocaine in doses > 40mg when incidences of 10 – 40% have been reported.

Concentration and baricity appear to be less important factors than the dose. In contrast,

bupivacaine is associated with a 0-1% incidence of TNS7.

Patient satisfaction

Day case SAB is associated with a reduced incidence of many of the post-operative

symptoms so disliked by our patients. Theses include PONV, poor pain control, sore throat

and grogginess. Many of our patients have specifically requested regional anaesthesia and

follow-up data reveals high patient satisfaction scores.[2]

Where patients have significant co-morbidities that make GA undesirable, the use of low-

dose SAB may be the deciding factor that allows the patient access to the DSU and all its

inherent advantages. For those who are still in doubt, post-discharge telephone calls will

provide reassurance that patients really do appreciate spinal anaesthesia.


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Classification

The two most commonly used classification systems for diaphyseal femoral fractures are the

AO-OTA system (Figure 1) and that described by Winquist (Figure 2).

Both systems are useful in predicting axial and rotational instability of the fracture and

therefore help with management planning. Neither is necessarily predictive of outcome or

time to union.

The AO-OTA system uses an alphanumeric code to describe the bone involved, which

segment of the bone, and the fracture pattern/energy.[6]

For the femoral diaphysis (bone 3, segment 2) the patterns of fracture are described as simple

(A), wedge (B) and complex (C) with further subdivisions (Figure 1).

Winquist described the degree of comminution in a fracture and thus the degree of cortical

contact or continuity (Figure 2).[7]

The Winquist classification has been modified to include segmental bone loss as well as

simple (non-comminuted) fractures(Assessment and initial management In the polytrauma

and major trauma situation patients are typically assessed and managed according to

standardized protocols, such as the Advanced Trauma and Life Support (ATLS) system.

Femoral fractures can be a major source of blood loss and should be splinted as a means of

haemorrhage control. In clinical situations where patients present with isolated femoral

injuries, or not as part of a major trauma situation, a thorough history and clinical

examination is mandated.

History

This can be taken from the patient and/or paramedics and will give valuable clues as to the

mechanism of injury and the potential for associated soft tissue and skeletal injuries. The

+++++


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Figure 1: AO-OTA classification of femoral diaphyseal fractures. +patient’s general

medical status, drug and past medical history, allergies, co-morbidities, timing of last

food and drink and other relevant clinical information are essential to the pre-operative

assessment.

Examination

Examination of the affected limb should include a neurological and vascular assessment and

a visual inspection of the soft tissues, including a careful assessment for compartment

syndrome.

Imaging

Plain radiographic imaging is usually sufficient for diagnosis and operative planning and

should include the ipsilateral hip and knee to rule out an associated femoral neck fracture or

articular injury. Computed tomography (CT) is usually reserved for major trauma patients

undergoing trauma CT or for patients who require CT angiography to assess possible

vascular injuries.


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Initial management

Splintage of the femoral fracture, initially in the form of fixedpoint traction, typically against

the pubis and ischium, provides the best analgesia and can allow for gross correction of

rotational malalignment. These splints should be removed early to reduce the risk of pressure

necrosis and pudendal nerve injury.

Balanced traction (skin or skeletal) can be used in patients who are waiting for surgery and

are physiologically well. In terms of pain relief, adequate oral and intravenous analgesia and

regional femoral nerve block with local anaesthetic should be considered. Fluid resuscitation

(blood product or crystalloid) should be administered as required.

Timing of surgery

The 1980‟s heralded the era of Early Total Care (ETC), as part of which definitive surgical

fixation was achieved at the index operation, typically within the first 24 h after injury.

Increased appreciation and understanding of the physiology of trauma patients saw a shift

towards Damage Control Orthopaedics (DCO), reaching its peak in popularity in the

2000‟s.[9]

If the injury causing the fracture is considered the „first hit‟ to the patients systemic

inflammatory system, then any surgical intervention subsequently is considered the „second

hit‟.

The „first hit‟ primes the inflammatory cascade and causes a degree of Systemic

Inflammatory Response Syndrome (SIRS).

Any secondary insult can tip the response into overdrive, leading to worsening SIRS and

ultimately Multi-Organ Dysfunction Syndrome (MODS).

DCO relies on moving the large „second hit‟ associated with definitive surgery out of the

window of hyperinflammation, and allows time for the patient to be stabilized and reduce the

physiological burden of reconstructive surgery (Figure 3).

DCO still requires there to be a „second hit‟ in the early post injury phase, in the form of

temporizing surgery (haemorrhage control, debridement of open wounds, vascular repair and

rapid external fixation), but this insult is smaller and typically avoids the instrumentation of

the femoral canal that is so physiologically taxing.[10]


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Significant reductions in mortality and complications were seen as a consequence of the shift

to DCO in femoral fracture patients. Morshed et al., showed that waiting just 12 h before

fixation in patients with an Injury Severity Score (ISS) of over 15 reduced mortality by

50%.[9,11]

In the last 10 years, focus has shifted towards trying to identify which patient groups can

have their femoral fractures treated early and which should wait.

Three patient groups are now considered: those who can have their fractures treated early

(ETC), those who must wait (DCO) and those who fall in between e the so-called „borderline

patient‟.

Physiological parameters such as venous lactate, interleukin-6 (IL-6), temperature,

coagulopathy and respiratory function have all been shown to be useful in guiding this

decision making process. Rising lactate (>2.5 mg/dl) and IL-6 (>200 pcg/L), falling

temperature and altered clotting parameters are good predictors of SIRS and mortality after

trauma and thus can be used as indicators that DCO is probably needed.

It is the „borderline patient‟ who must be looked at closely.

These patients typically have femoral fractures (single or bilateral) with pulmonary injury but

no other major system injury (Table 2).

Those with pulmonary dysfunction and those with bilateral fractures are physiologically

considered to be as ill as polytrauma patients and may be best served with DCO treatment.15

In stable patients, primary femoral nailing is associated with shorter ventilation times. In

borderline patients, it is associated with a higher incidence of lung dysfunction when

compared to those that receive initial external fixation.[16]

In the absence of major head or chest injuries, patients with multiple injuries and bilateral

femoral shaft fractures have a similar complication rate to polytrauma patients with unilateral

fractures.[17,18]

In patients with head injury and femoral fractures (without other body system

injuries) no greater risk is seen with early fixation as long as the patient is resuscitated

adequately.[19,20]


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Definitive treatment

Rarely are fractures of the femoral shaft in adults treated without operative intervention. Skin

or skeletal traction, as definitive methods of fixation, are now largely historical although

occasionally may still be used. Non-operative methods are associated with high rates of

malunion and shortening. The commonest surgical method of treating femoral shaft fractures

is using an intramedullary nail. Modern nailing traces its origins to K€untscher in 1939, but

descriptions of intramedullary devices have been found from well before the 20th Century.[21]

Intramedullary nailing

Nail design: despite early scepticism of the methods of K€untscher and his intramedullary

device, the concept and use of nailing was eventually embraced and nails have now evolved

into highly engineered orthopaedic devices. Nails are typically made from either titanium

alloy or stainless steel. Even though titanium has an elastic modulus approximately half that

of steel, this difference in material has little effect upon union or failure rates with modern

generation nails. The size of the nail, however, does have an effect, with thicker nails of a

larger external diameter having significantly higher fatigue strength than thinner nails. It has

been shown that nails with an external diameter of 11e12 mm have a bending stiffness over

50% greater than smaller cannulated nails.[22]

Older generation nails were typically thin-walled and may or may not have been slotted.

These nails were weak in torsion, although offered excellent interference fit within the

femoral canal. Modern generation nails are thick walled and no longer rely on slotted

geometry to facilitate insertion, but rather rely more on anatomic contouring. Typically nails

now have a radius of curvature (150 cm) that is nearer that of the radius of curvature of the

femur (around 120 cm) compared to the straight nails of old. Most modern generation nails

are cannulated to facilitate insertion e by keeping the cannulation small there is little effect on

the strength of the nail. Flutes may be present to facilitate rotatory stability of the nail and to

reduce intramedullary pressure at the tip of the nail on insertion. All modern nails offer

multiple locking options both proximally and distally.

Patient set up: in the broadest sense, femoral nailing can be performed freehand on a

radiolucent flat-topped trauma table or in traction on a fracture reduction table. Both can be

used with the patient either supine or in a lateral position.


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Faster operating times and less risk of malreduction have been shown with freehand

techniques, but there is no difference in functional outcome or other parameters.[23]

Traditional fracture table techniques rely on the application of traction through the leg

extension with foot piece, or via a traction pin in the distal femur. This allows application of

traction, rotation and point is at the anterior end of Blumensaat‟s line on the lateral

projection, essentially at the top of the intercondylar notch, in line with the femoral shaft.

This technique is commonly used in ipsilateral neck-shaft fractures (see below), fractures

below old implants (such as compression hip screws), in obese patients where antegrade entry

points are difficult to access, and in ipsilateral femoral and tibial shaft injuries. It has also

been used in Damage Control Orthopaedics, employing the technique of rapid nailing with

small diameter implants.

Retrograde techniques have been shown to have a higher incidence of malrotation and

shortening than antegrade, and there may be an association with knee pain. There was

previously thought to be a risk of knee sepsis in retrograde nailing of open fractures but this

has not subsequently been proved to be the case.

There is little difference in functional outcome, time to union and malunion comparing

antegrade and retrograde nailing. Unsurprisingly, antegrade nails cause more problems

related to the hip and retrograde give problems with the knee.

Reduction methods: whilst every effort is made to reduce and align the fracture appropriately

before the operative procedure begins, it is not uncommon for additional reduction

manoeuvres to be required during the nailing procedure. The nail is inserted and locked at

sites away from the fracture and zone of soft tissue injury, and intramedullary nailing relies

on the applying the principles of relative stability techniques and healing by secondary

intention. Every effort should be made to preserve the biology of the fracture site and open

reduction techniques should be avoided if possible.

Intramedullary techniques to assist fracture reduction include bending the tip of the guidewire

to allow for control in guiding into the centre of the distal segment, and also the use of a rigid

cannulated scoop to guide the wire across the fracture site.

Another method is to ream and insert the nail into the proximal segment, and then use the nail

itself as a joystick to align the fracture and pass the wire through the nail. The nail can then


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be backed out and reaming of the distal segment can be achieved e this technique is good for

mid diaphyseal fractures and can be used in unreamed nailing with ease Extramedullary

techniques can be closed, instrumented or fully open. Closed techniques include use of

mallets as pushers, and the PORD or a crutch to reduce posterior sag. The F-tool is a

radiolucent device with adjustable limbs that allows for the application of countering forces

either side of the fracture to aid reduction. Historically described techniques include the use

of sheets around the limb to be pulled in opposing directions.

Instrumentation of the fracture fragments may be needed.

This need not be a fully open procedure. The use of Schanz pins as joysticks, or attached to a

femoral distractor, are examples of this. Full open reduction in the acute setting should be

avoided if possible. Perhaps an exception to this is the use of a clamp or cable to reduce a

subtrochanteric fracture, as any malreduction here (especially varus) will lead to an increased

risk of implant fatigue failure. Colinear reduction clamps have a smaller footprint than Hey-

Groves or Verbrugge clamps and require smaller incisions; nonetheless, their use still leads to

a disturbance of the fracture biology.

Reamed vs Unreamed and union rates: early nails were all unreamed. Although flexible

reaming was developed by K€untscher, it was not popularized until the 1980s. Reaming

disturbs the endosteal blood supply. There is a shift in the balance of blood flow in favour of

the periosteal system after nailing e it is noted that the early callus in intramedullary nailing is

periosteal, not medullary. Over 6e12 weeks the endosteal blood supply recovers and allows

the formation of internal callus. Contrary to popular belief, unreamed nails also disturb the

endosteal blood supply but to a lesser extent. However the reactive increase in periosteal

blood flow is less in unreamed nails and this may help explain why they may not offer as

predictable or rapid time to union as reamed nails. Several studies (including many

randomized control trials) have now shown that reaming increases union rates in acute

fractures. There is up to a 5x risk of nonunion in unreamed nails.

Reaming: systemic effects, fat embolism syndrome: reaming is a physiologic insult and

while any surgery is considered a second hit, there is no doubt that the demands on the patient

are greater if the second hit involves nailing, even more so if reaming is used. Any

instrumentation of the femoral canal causes a rise in intraosseous pressure that forces fat and

inflammatory exudate into the venous circulation.


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This leads to up-regulation of the systemic inflammatory response and it is this that can be

physiologically catastrophic for the polytrauma patient e hence the advent of DCO.

M€uller demonstrated that it is the first broaching of the canal and the initial instrumentation

that cause the highest pressure spikes, not the reamers themselves. Although the reamers do

induce lesser pressure spikes, the subsequent insertion of the nail gives another more

significant peak. As such, it can be seen that unreamed nails are equally at risk of inducing a

physiologic response. Others have shown that using the hand awl rather than an initial reamer

cutter reduces pressure. Rapid penetration of the reamer in both proximal and distal

metaphyses causes much higher pressures than reaming the cortex of the diaphysis, and the

speed of penetration and volume of the reaming shaft classic textbook description is a triad of

rash, confusion and hypoxia. It is considered a systemic response to embolized fat globules.

Two theories exist as to why these globules appear in the blood. The mechanical theory is

supported by the fact that fat is typically liberated by reaming the femoral canal, although can

occur due to the fracture itself. Reaming is associated due to the high intraosseous pressures

achieved, forcing fat into the systemic circulation, it is assumed, via the venous drainage

system of long bones. The second theory is the metabolic theory and is supported by the fact

that the inflammatory response induces change in the chylomicrons (fat carrying protein-

based components in the circulating blood) resulting in de novo synthesis and accumulation

of fat globules away from the site of injury. Fat embolism is seen in up to 3% of patients with

isolated long bone trauma and in up to 15% of polytrauma victims; it can be fatal in up to

15% of cases. The management of fat embolism syndrome revolves around the combination

of supportive therapy for the pulmonary injury and stabilization of the long bone injuries.

Reaming: reamer design, RIA: reamers should be sharp. Blunt reamers generate more heat

and risk thermal necrosis of the endosteal bone. No significant difference has been shown

between different types of reamer head design, though the ratio of the shaft to head is

important. A narrow shaft significantly reduces reaming pressures. In the last decade the use

of suction and irrigation reamers has been well described. The Reamer Irrigator Aspirator

(RIA) (DePuy Synthes, Warsaw, Indiana) incorporates a single reamer head, sized

appropriately for the desired amount of bone to be removed. It is used in graft harvest,

debridement of intramedullary infection and nailing in acute trauma. The irrigation and

suction reduces the volume of embolized fat and reduces reaming temperature. There are

fewer systemic effects with RIA compared to standard reaming in acute trauma and the


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benefit of a single reamer pass on reducing operating time is significant.However, the RIA is

technically challenging and unforgiving in use, with recent reports of iatrogenic fracture

being described.

Correct rotation, correct length: correct angulation, rotation and length are the goals of all

methods of fixation in long bone fractures. The use of an intramedullary nail in diaphyseal

fractures lends itself to achieving correct angulation, although proximal and distal

diaphysealemetaphyseal junction fractures require careful placement of the guidewire to

prevent eccentric positioning of the nail and thus an induced angular deformity.

Correct rotation and length are harder to achieve. As mentioned above, different methods of

set-up will influence the surgeon‟s ability to assess and correct rotation and length. If

possible, every effort should be made to assess the uninjured side preoperatively as a

comparison and template.

Assessment of rotation intraoperatively can be made using one of two principal methods. The

first is the cortical step sign.

This relies on the same cortex (medial or lateral) either side of the fracture being the same

diameter, indicating correct rotation.

Femoral malrotation after nailing is common, reported in up to 20e30% of cases. However it

would seem that only deformities of 15 degrees or more are clinically and functionally

significant, with external rotation deformities causing the most symptoms. An appreciation of

the risk of malrotation with femoral nailing, and applying simple steps as outlined above to

overcome the problem, can lead to a 50% reduction in incidence.

Locking and working length: almost all modern intramedullary nails offer the option of

locking proximally and distally. It is important to note that the locking bolts are bolts, not

screws, having very large core diameter to thread diameter ratios.

The working length of a nail is essentially defined by the distance between the two closest

points of stable contact the nail makes with bone either side of the fracture. This can be the

distance between locking bolts, although if there is a good contact between nail and bone at

the isthmus, this can affect the working length. Leaving a nail unlocked at one end can be

safe in either proximal or distal third fractures, where there is a good isthmic fit.


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Here the working length of the nail is between the isthmic point of contact and the locked

screws the other side of the fracture, thus eliminating the need to lock the far end of the nail.

Historically the gold standard for femoral nailing has been reamed, statically locked nails, as

shown in a series of landmark papers by Brumback. His work showed that static locking does

not impede fracture healing compared to dynamic locking of nails.

There is little evidence to support the dynamization of nails either acutely or in a delayed

fashion to prevent or treat nonunion.

Rarely, nails can be left unlocked either proximally, distally, or both: predominantly in

axially and rotationally stable fractures. This is an unusual beast, however, as an axially

stable fracture is typically transverse and thus rotationally unstable and vice versa.

The size and number of locking bolts, along with their configuration, is important. Bolts of

less than 5 mm diameter have significantly lower fatigue strengths and are prone to early

failure.

A 20% increase in core diameter equates to a 50% increase in bending strengthehence a

5mmbolt is significantly stronger than a 4 mm bolt e there is a 20% difference in diameter.

Although most research on locking bolts relates to tibial implants, the evidence is against

using narrow diameter bolt and this is translated to all nailing settings.

Femoral Neck Fracture

Femoral neck fractures are intracapsular and typically occur in a bimodal age distribution,

with most occurring in the elderly population.

The incidence of femoral neck fractures increases with age. The patient‟s medical history and

preinjury status (ie, prior hip pain, ambulatory status, functional and mental capacity) provide

valuable information that may influence the treatment course.

Nondisplaced Femoral

Neck Fracture

Whether to manage nondisplaced femoral neck fractures nonsurgically or surgically is a topic

of debate. Elderly patients with medical conditions that place them at high risk for anesthesia-

and surgery-related complications can be treated nonsurgically.


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Nonambulatory patients and patients suffering from severe dementia who have minimal

discomfort may also be treated nonsurgically. Surgical fixation for nondisplaced fractures

allows early patient mobilization and ensures that a nondisplaced fracture does not

subsequently displace.

Currently, there are no level I or II studies comparing nonsurgical with surgical management

of nondisplaced femoral neck fractures.

We evaluated two level III studies and one level IV study of nondisplaced femoral neck

fracture. Hansen5 performed a nonrandomized study involving 23 patients, 16 of whom were

treated nonsurgically and 7 of whom were treated surgically with sliding hip screws (SHSs).

Nonunion occurred in 10 of 16 patients treated nonsurgically and in none of the surgically

treated patients.

Nine of 16 patients with a nonunion required revision surgery, whereas only 1 surgically

treated patient required revision surgery.

An 86% union rate was reported in one study of 170 consecutive patients with impacted

femoral neck fractures who were treated with early mobilization and weight bearing.6

Patients older than age 70 years and in poor general health had the highest rate of secondary

displacement. In a series of 1,400 patients, Parker et al7 performed a cost-benefit analysis of

various methods of treatment of hip fractures.

The authors estimated a 30% 1-year mortality rate for patients whose nondisplaced subcapital

fractures were treated nonsurgically and who had an uneventful union. For those patients with

displaced subcapital fractures, the authors predicted a 90% 1-year mortality rate secondary to

pneumonia, bedsores, and pulmonary emboli.

Conn and Parker8 examined 375 patients with nondisplaced intracapsular fractures treated

with internal fixation. The authors noted a nonunion rate of 6.4% and an osteonecrosis rate of

4.0%. Age, walking ability, degree of impaction evident on the anteroposterior radiograph,

and angulation on the lateral radiograph were determined to be predictive of healing

complications. In this study, the conversion rate to arthroplasty was 7.7%.


383


Based on the available evidence, a recommendation cannot be made regarding the treatment

of nondisplaced femoral neck fractures (Table 1). The patient who is treated nonsurgically is

not at risk of surgeryrelated complications, including wound infections or complications

associated with anesthesia. However, the nonunion rate is increased, as are complications

associated with prolonged recumbency. Although further randomized trials would provide

more data, they may be difficult to conduct based on the modern standard of care and the

limited indications for nonsurgical treatment.

Displaced Femoral

Neck Fracture

The patient with a displaced femoral neck fracture is at significant risk for osteonecrosis and

nonunion. Treatment options include closed reduction and internal fixation or ORIF with

different constructs, hemiarthroplasty (unipolar and bipolar), and THA.

Internal Fixation

Many constructs have been used for internal fixation, including multiple screw fixation in a

variety of configurations and SHSs. In our attempt to determine whether a particular implant

provides superior fixation, we assessed outcomes such as rates of nonunion and

osteonecrosis, need for hardware removal, periprosthetic fracture, and implant failure.

The following data are all from level I studies.

A recent review of the Cochrane database revealed 28 randomized or quasirandomized trials

of 5,547 patients with femoral neck fractures treated with 19 different pin and/or screw

constructs in a variety of configurations.

9 None of the implants had significantly superior results for outcomes related to fracture

healing, osteonecrosis, wound infection, pain scores, reoperation rate, use of walking aids,

periprosthetic fracture, or mortality.

Seven studies compared outcomes between SHSs and various cancellous screws. Four studies

noted shorter surgical times with cancellous screws (average, 11 minutes).[10-12]

One study

reported surgical times to be equivalent between the fixation methods.[13]

In the SHS group, there was a tendency toward increased blood loss (average, 84 mL), and

deep wound infection was more common. Although the overall reoperation rate was


384


equivalent between the groups, failure of fixation was lower in the SHS group. There was not

a significant difference in mortality between the groups.

Parker and Blundell14 conducted a meta-analysis of 25 randomized controlled clinical trials

(RCTs) involving 4,925 patients with intracapsular fractures who were treated with a variety

of implants. The review and analysis were focused on complications associated with fracture

healing.

No investigated device proved to be superior to any other in terms of nonunion or fracture

displacement.

There was limited evidence supporting screw fixation over smooth pins; however, this

advantage was negated with the use of a hook at the end of the pin. No advantage was seen in

using a side plate for fixation, and no significant evidence was found concerning the number

of screws necessary for fixation.

Based on the available evidence, there appear to be minimal differences between implants

used for internal fixation of displaced femoral neck fractures (Table 2). These studies did not

break down the data strictly based on age. Thus, it is not possible to recommend a particular

implant for age-specific populations.

The choice of implant should be based on surgeon familiarity and comfort level.

Internal Fixation Versus

Hemiarthroplasty

Multiple studies have been doneon the outcomes of internal fixationof femoral neck fractures

versus arthroplasty(eg, hemiarthroplasty, THA). The risk of osteonecrosis, nonunion, and

revision following internal fixation of displaced intracapsular fractures.

A review of the Cochrane database produced 13 randomized or quasirandomized controlled

trials with a total of 2,091 patients treated with either internal fixation or hemiarthroplasty.

One clear limita.

DISCUSSIONS

Shivering is an involuntary, repetitive activity of skeletal muscles. The mechanisms of

shivering in patients undergoing surgery are mainly intraoperative heat loss, increased

sympathetic tone, pain, and systemic release of pyrogens.[12]

Spinal anesthesia significantly


385


impairs the thermoregulation system by inhibiting tonic vasoconstriction, which plays a

significant role in temperature regulation.[13]

Spinal anesthesia also causes redistribution of

core heat from the trunk (below the block level) to the peripheral tissues. These two effects

predispose patients to hypothermia and shivering.[14]

The median incidence of shivering

related to regional anesthesia observed in a review of 21 studies is 55%.[11]

Shivering

increases oxygen consumption, lactic acidosis, carbon dioxide production, and metabolic rate

by up to 400%.[15,16]

Therefore, shivering may cause problems in patients with low cardiac

and pulmonary reserves. The best way to avoid these intraoperative and postoperative

shivering-induced increases in hemodynamic and metabolic demands is to prevent shivering

in the first place.[12]

Recently Ketamine and Ondansetron have been tried to prevent shivering

during anaesthesia with good results.

Low dose ketamine is economical, easily available and easy to administer while no study in

our hospital was conducted before however, we planned this study to compare the efficacy of

two drugs for control of perioperative shivering so that drug which is cost effective and has

better efficacy will be used in future in our setting.

Basic demographics like age, gender, mean weight and height and type of surgery patients

underwent were similar and having no significant difference in both groups, while on

comparison of frequency of shivering in both groups revealed, 4.69%(n=6) in K Group and

11.72%(n=15) in O Group while remaining 95.31%(n=122) in K and 88.28%(n=113) in O

Group had no findings of the such morbidity, p value was calculated as 0.03, which shows

significant difference.

The findings of our study are in agreement with an Indian study by Shakya B and co-workers

who studied the effect of low dose ketamine, ondansetron and saline on patients undergoing

spinal anaesthesia for control of perioperative shivering and concluded that shivering was

2.5% in ketamine group, 10% in ondansetron group and 42.5% in placebo group showing

superiority of low dose ketamine with p<0.05 for control of perioperative shivering.[11]

Multiple researchers found that ketamine 0.5 mg per kg IV was effective like pethidine 20-25

mg IV. Ketamine prevents shivering by non-shivering thermogenesis at the level of

hypothalamus or by the beta adrenergic action of norepinephrine. Nausea and vomiting was

low in this group, may be due to low dose of ketamine.


386


Dal et al studied that ketamine 0.5mg kg -1 was effective in prevention of post anaesthetic

shivering in patients undergoing general anaesthsia.[17]

Sagir et al also found that 0.5mg kg -1

of ketamine was effective in prevention of shivering during spinal anaesthesia.[18]

In our study, the effectiveness of ondansetron and ketamine was compared, ketamine was

found to be more effective in prevention of shivering, p< 0.05. Ketamine has sympathetic

stimulation and vaso-constrictive effect which explains the less incidence of hypotension

with lesser requirement of vasopressor. Mild sedative effect was observed in ketamine group

which was considered as an advantage during surgery under spinal anaesthesia.

In our study, we found the hypothesis “Efficacy of prophylactic intravenous administration of

low dose ketamine (0.25mg/kg) is more as compared to ondansetron in prevention of

shivering during spinal anaesthesia” is justified and ketamine may be used in patients

undergoing lower abdominal surgeries.

CONCLUSION

1. The result of the study conclude that prophylactic intravenous administration of low dose

ketamine (0.25mg/kg) is significantly more effective than ondansteron during spinal

anesthesia for prevention of perioperative shivering in patients undergoing lower

abdominal surgeries.

2. Femoral shaft fractures in adults are reasonably common and can occur in isolation or in

association with other injuries. They are typically high-energy in aetiology, especially in

young adults, and require special consideration to the physiological impact of injury on

the patient. The evolution of treatment for these fractures has seen changes in the timing

of surgery as well as the techniques employed, but the principles of stable internal

fixation remain. Good outcomes and low complication rates can be expected if the

operating surgeon has a thorough understanding of the anatomy, basic science and

surgical technique relating to the treatment of femoral shaft fractures

REFERENCES

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spinal anesthesia and femoral fractures

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