Pain Management

Pain Management

The management of pain is important not just for humanitarian also to improve and reduce postoperative complications.

Pain assessment: visual, verbal, numerical, Faces pain scale.

World Health Organization (WHO) Step Ladder Approach

Mild Pain 1-3/10

Moderate Pain 4-6/10

Severe Pain 7-10/10

ASA, Paracetamol,NSAIDS

Weak opioids +/- non-opioids (e.g. paracetamol)

Potent opioids (e.g.morphine) +/-non-opioids

Routes of analgesic delivery

Oral:• Simplest route available• The bioavailability is limited to 1st pass

metabolism• The oral route is not suggested following

major surgery due to potential delays in gastric emptying

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The non-steroidal anti-inflammatory drugs are probably the most widely used group of drugs in the world. Indications for their use are:

• acute pain following surgery • renal colic

• chronic pain arising from inflammation • opioid-sparing

• prophylactic treatment of cardiovascular and thrombotic related diseases

• antipyretic effect.

Side-effects1. Gastric toxicity.

2. Renal complications. 3. Haemostatic impairment.

4. CNS toxicity. 5. Dermatological effects. 6. Aspirin-induced asthma. 7. Haematological effects.

8. Hepatotoxicity. 9. Teratogenic effects. 10. Drug interactions.

Intermittent subcutaneous or intramuscular injection

Advantages:• Safe if it administered more regularly• Familiar practice• Gradual onset of side-effects• Inexpensive.

Disadvantages:• Painful injections• Fluctuating plasma concentration• Delayed onset of analgesia

Intravenous bolus• For the management of severe acute pain.• It gives the quickest onset and repeated

doses can be titrated against effect.• Close supervision of the patient is

required.• This method is not appropriate for

continuing pain management at ward level

Intra nasal bolus• Efficacy and speed of action are similar to

that I.M. • It offers an alternative method of

administration for areas such as emergency department and pediatric units

Continuous intravenous infusion

Advantages:• Rapid onset of analgesia• Steady-state plasma concentrations• Painless• Pain control may be superior to PCA spc.

For major surgery

Disadvantages:• Fixed dose not related to

pharmacodynamic variability• Errors may be fatal• Expensive fail-safe equipment required• Close monitoring of the patient is

important to detect respiratory depression or over-sedation

Patient-controlled analgesia (PCA)

• Intravenous PCA is now a standard method of providing postoperative analgesia in many hospital worldwide

• PCA can give high-quality analgesia but can fail if not applied appropriately

• PCA can be used for most surgery where moderate to severe postoperatively pain is expected

• With PCA the patient determines the rate of i.v. administration of the drug thereby providing feedback control.

• PCA equipment comprises an accurate source of infusion, coupled to an i.v. cannula and controlled by patient-machine interface device. Safety features are incorporated to limit the preset dose, the number of doses which may be administered and the lock out period between doses. The drug that has been most commonly used with PCA is morphine

Advantages:• Dose matches patient’s requirements and

therefore compensates for pharmacodynamic variability

• Doses given are small and therefore fluctuations in plasma concentrations are reduced

• Reduces nurses’ workload• painless

Disadvantages:

• Technical errors may be fatal

• Expensive equipment

• Requires ability to cooperate and understand

Epidural• Its superior to i.v. PCA for the management of pain

following major abdominal surgery and lower limb amputation

• Its safe to use at ward level, but this dependent on adequate monitoring and on nursing staff who have received specific training in caring for patient with epidural infusions

• Used mainly for the management of pain during child birth and following major abdominal, thoracic orthopedic and vascular surgery

• Opioids exhibit 10 times the potency when administered via the epidural route as opposed to the intravenous route

• A combination of local anesthetic and opioid is usually administered the two drugs act synergistically resulting in superior analgesia and improved side effect profile

Contraindication to epidural:1. Anticoagulation or coagulopathy2. Hypovolemia3. Local infection, septicemia4. Lack of patient consent

In addition to its analgesic effects, the utilization of epidural analgesia may decrease the incidence of DVT following orthopedic surgery and improve circulation following vascular surgery

Thank You