anaesthetic management of obstetric emergencies
DESCRIPTION
anaesthetic management of obstetric emergenciesTRANSCRIPT
Dr sheeba hakakWaterford regional hospital
Definition
Obstetrical emergencies are life-threatening medical conditions that occur in pregnancy or during or after labor and delivery.
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Massive obstetric haemorrhage1. MOH is a major cause of maternal death and
morbidity2. Variably defined as; . blood loss >1500ml . decrease in hb >4g/dl or .acute transfusion requirements >4 units3. The gravid uterus receives up to 12% of cardiac
output ,thus OH can be un expected and rapidly become life threatening.
Classification
Antepartum placenta previa/accreta placental
abruption uterine rupture
Post partum uterine inversion uterine atony birth trauma or
laceration
ANTEPARTUM HEMORRHAGE
Per vagina blood loss after 20 weeks’ gestation.
Complicates close to 4% of all pregnancies and is a MEDICAL EMERGENCY!
Is one of the leading causes of antepartum hospitalization, maternal morbidity, and operative intervention.
Placenta Previa
Defined as a placenta implanted in the lower segment of the uterus, presenting ahead of the leading pole of the fetus.
1. Total placenta previa. The internal cervical os is covered completely by placenta.
2. Partial placenta previa. The internal os is partially covered by placenta.
3. Marginal placenta previa. The edge of the placenta is at the margin of the internal os.
4. Low-lying placenta. The placenta is implanted in the lower uterine segment such that the placenta edge actually does not reach the internal os but is in close proximity to it
Placenta Previa
Incidence about 1 in 300
Perinatal morbidity and mortality are primarily related to the complications of prematurity, because the hemorrhage is maternal.
Etiology
Advancing maternal age Multiparity Multifetal gestations Prior cesarean delivery Smoking Prior placenta previa
Placenta Previa
The most characteristic event in placenta previa is painless hemorrhage.
This usually occurs near the end of or after the second trimester.
The initial bleeding is rarely so profuse as to prove fatal.
It usually ceases spontaneously, only to recur.
Placenta Previa
Placenta previa may be associated with placenta accreta, placenta increta or percreta.
Coagulopathy is rare with placenta previa.
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Diagnosis.
Placenta previa or abruption should always be suspected in women with uterine bleeding during the latter half of pregnancy.
The possibility of placenta previa should not be dismissed until appropriate evaluation, including sonography, has clearly proved its absence.
The diagnosis of placenta previa can seldom be established firmly by clinical examination. Such examination of the cervix is never permissible unless the woman is in an operating room with all the preparations for immediate cesarean delivery, because even the gentlest examination of this sort can cause torrential hemorrhage.
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The simplest and safest method of placental localization is provided by transabdominal sonography.
Transvaginal ultrasonography has substantively improved diagnostic accuracy of placenta previa.
MRI
At 18 weeks, 5-10% of placentas are low lying. Most ‘migrate’ with development of the lower uterine segment
Placenta PreviaManagement Admit to hospital
NO VAGINAL EXAMINATIONNO VAGINAL EXAMINATION
IV access
Placental localization
Placenta PreviaManagement
Severe bleeding
Caesarean section
Moderate bleeding
Gestation>34/52
<34/52
ResuscitateSteroids Unstable
Stable
Resuscitate
Mild
bleeding Gestation<36/52
Conservative care
>36/52
Anaesthetic management for previa Examine the airway in case emergency G/A
is required and provide aspiration prophylaxis
Ask OB about involvement with any previous cesarean scar on ultrasound [risk of accreta]
Place two large bore IV lines and have warmers available.
Assure that blood is type and cross matched.
What type of anaesthetic?
Anaesthetic management of previa A review of 514 women with placenta
prtevia found: No difference between G/A or regional
anaesthesia in anaesthetic or operative complications.
G/A was associated with increased EBL and transfusions and decreased post op Hgb.
Am J Obstet Gyn 1999;180:1432
Anaesthetic management for previa A retros pective review 350 consective cases
of plcenta previa [ 60% using regional anaesthesia, 40% using G/A found:
. decreased EBL with regional vs G/A
. decreased transfusion with regional.
. no diff in incidence of hypotension. .two spinals were converted to G/A
secondry to c-hyst. Br J Anaesth 2000;84;725
Interventional radiology
Prenatal diagnosis of palcenta accreta/percreta is now becoming more common[vs diagnosis at delivery]
Have a care conference in advance with anaesthesiology ,OB,nursing and interventional radiology present.
Placental Abruption
Defined as the premature separation of the normally implanted placenta.
Occurs in 1-2% of all pregnancies
Perinatal mortality rate associated with placental abruption was 119 per 1000 births compared with 8.2 per 1000 for all others.
Placental Abruption
external hemorrhage concealed hemorrhage Total Partial
Risk factors for abruption Hypertension,chronic or pregnancy-
induced Age>35yrs Multiparity Smoking Cocaine use Abdominal trauma Premature rupture of membranes Hx of previous abruption
Diagnosis of abruption
Vaginal bleeding with abdominal pain
Uterine hypertonicity Fetal distress Retroplacental clot The presentation can be quite
variable and difficult to diagnose
OB management of abruption Evaluate maternal stability[vital
signs,coagulation studies] Evaluate fetal well-being and
maturity If severe fetal distress and/or
maternal instability ...........urgent C/S If stable mother and
fetus......induction of labor and vaginal delivery
Anaesthetic management of abruption Assure good IV access and
availability. Regional techniques are appropriate
if maternal volume staus and coags normal
If G/A is indicated,consider induction with etomidate or ketamine
Have several oxytocics available for treatment of uterine atony.
Uterine rupture
Risk factors for uterine rupture Previous uterine surgery Abdominal trauma Uterine trauma Grand multiparity Fetal macrosomia Fetal malposition
Diagnosis of uterine rupture Fetal distress Cessation of uterine contraction [ in
labor] Vaginal bleeding Abdominal pain
OB management of uterine rupture Uterine repair. Hysterectomy ANAESTHETIC MANAGEMENT. Depends on ease of repair ,but be
prepared for G/A and volume replacement.
PPH
The mean blood loss in a vaginal delivery is 500 ml & 1000 ml for cesarean section.
Definition: Blood loss greater than 500 ml for vaginal and
1000 ml for cesarean delivery. However, clinical estimation of the amount of
blood loss is notoriously inaccurate. Another proposed definition for PPH is a 10%
drop in haematocrit.
PPH Risk Factors
PPH Risk Factors
PPH Risk Factors
PREVENTION OF PPH
Although any woman can experience a PPH, the presence of risk factors makes it more likely.
For women with such risk factors, consideration should be given to extra precautions such as: IV access Coagulation studies Crossmatching of blood Anaesthesia backup Referral to a tertiary centre
OB MANAGEMENT OF PPH
Bimanual uterine compression and massage
Infusion of oxytocin Evaluation for retained placenta Use of other oxytocics
ANAESTHETIC MANAGEMENT OF PPH1. Volume resuscitation large bore IVs ,monitors,warmers2. Analgesia pre existing epidural,ketamine,G/A3. Oxytocics4. Move to OT sooner rather than later.5. Consider notifying interventional
radiology.
Oxytocic drugs
Drug/dose Oxytocin 20-80u/l Methergine 0.2mg
IM
Hemabate ..prostagladin F2alpha 250 mcg IM
Side effects vasodialation with
IV bolus,hyponatremia
Diffuse vasoconstriction,pulmonary and systemic htn,coronary vasospasm,nausea
Broncho spasm,pul htn,hypoxia,nausea,diarrhoea.
PRE ECLAMPSIA
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Definitions of Hypertensive Disorders in Pregnancy [1,2,4,5] Preeclampsia
Blood pressure elevation with proteinuria Occurs after 20 weeks of gestation Proteinuria
urinary excretion of 300 mg or greater of protein in 24 hr
Edema no longer diagnostic for poor specificity
Eclampsia seizures
Definitions of Hypertensive Disorders in Pregnancy [1,2,4,9] HELLP syndrome
defined by the presence of all 3 criteria: Hemolysis (abnormal peripheral
smear, bilirubin 1.2 mg/dL [20.5 µmol/L], or lactate dehydrogenase 600 IU/L)
Elevated liver enzymes (aspartate aminotransferase 2 x normal)
Thrombocytopenia (platelets <100 x 103/µL)
Aetiology
Exact aetiology unknown Possible causes 1. widespread endothelial
dysfunction leading to placental ischemia and multi organ dysfunction
2. synthesis of many substances like NO and PGI2 may be decreased in pre ecclampsia which leads to smooth muscle reactivity and platelet adhesion
Complications
Neurological Headache Visual disturbances Hyperexcitability Seizures Intracranial hemorrhage Cerebral edema
Pulmonary Upper airway edema Pulmonary edema
Cardiovascular Decreased intravascular volume Increased arteriolar resistance Hypertension Heart failure
Complications
Hepatic Impaired function Elevated enzymes Hematoma Rupture
Renal Proteinuria Sodium retention Decreased glomerular filtration Renal failure
Hematological Coagulopathy
Thrombocytopenia Platelet dysfunction Prolonged partial thromboplastin time
Microangiopathic hemolysis
Risk Factors [10]
Obesity Black race Chronic hypertension
Diabetes or insulin resistance Collagen vascular disease Thrombophilias Increased circulating testosterone Multiple gestation Previous preeclampsia
Management
Definitive treatment of preeclampsia is delivery
Whether or not to deliver the fetus gestational age maternal and fetal condition severity of preeclampsia
Patients at term delivered Remote from term Conservative approach Delivery at any gestational age
Maternal end-organ dysfunction Nonreassuring tests of fetal well-being
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Mgso4
Anticonvulsant of choice in preventing and treating fits.
Iv bolus 4 to 6 gms and then Infusion 1 to 2 gms/hr to keep sr mg in
therapeutic range [2-3 mmol/lt] Indicators of mgso4 toxicity...... ECG changes [3-5mmol/lt] loss of deep TR [5 mmlol/lt] resp dep [6-7.5 mmol/lt] cardiac arrest [12 mmol/lt]
Anaesthetic considerations Pre anaesthetic assessment1 Fluid balance and hemodynamics .hypo albuminaemia,increased cap
permeability,high hydrostatic pressure leads to risk of pul and pharyngolaryngeal oedema
2. Estimation of cardiac out put ......if .....oliguria ,pul oedema,htn resistant to initial therapy.
Coagulation Assessment of coag status is
essential before reg anaesthesia .
Epidural analgesia
Early epidural is an ideal form of pain relief in preceelamptic pts.
It helps to control the exaggerated hypertensive response to pain and can improve placental blood flow.
A functioning epidural may safely be etended for C/S.
Anaesthesia for c/s
Regional vs G/A 1 Avoidance of hypertensive
response to laryngoscopy [more in preecclamptics]
2 Blunting of neuro endocrine response to surgery
3 Prevention of transient neonatal depression associated vth G/A.
Spinal vs epidural Advantages 1. quicker and more reliable in on set 2. less potential trauma in the epidural
space. Dis advantages theoretical risk of more abrupt
hypotension in a pt who may be relatively hypovolumic and with a fetus who may be compromosed by palcental insufficiency.
Aternatively CSE used .....giving small dose of L/A in SA and option of utilizing the epidural as necessary.
General anaesthesia
G/A may be necessary Main concerns; 1.mucosal oedema of upper
airway 2.severe hypertensive
responses to laryngoscopy and surgery 3.pts on mgso4 may be very
sensitive to effects of NDMRs Difficult obstetric intubation trolley
ready.
Feotal distress
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DEFINITION
Foetal distress is defined as depletion of oxygen and accumulation of carbon dioxide,leading to a state of hypoxia and acidosis during intra uterine life.
causes
During labor; umblical cord prolapse umblical cord
compression [variable
deceleration] uteroplacental
insufficency [late
deceleration] At delivery; shoulder dystocia
management
Change maternal position Administer supplemental oxygen Maintain/improve maternal
circulation Give a tocolytic for hypertonicity Deliver ......forceps C/S
CLASSIFICATION OF C/S ACCORDING TO URGENCY Catagory 1 .requiring immediate delivery
[a threat to maternal and foetal life]
Catagory 2.requiring urgent delivery [maternal and foetal compromise that is not immediately life threatening] Catagory 3.requiring early delivery [no maternal or foetal compromise] Catagory 4.elective delivery [at a time suited to the women and
maternity staff]
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Thank you