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PAIN MANAGEMENT IN COLORECTAL DISEASES : An Update
D K Baheti
Associate Prof. and Head, Dept. of Anaesthesiology, Bombay Hospital Institute of Medical Sciences, 12, New Marine Lines, Mumbai - 400 020.
INTRODUCTIONThe pain relief is a basic human right and failure to relieve pain, is morally and ethically unacceptable. Although pain is a significant health problem, currently under treated. Colorectal area is the most sensitive one, and any problem in this area is often psychologically depressing, irritating apart, from being painful. It also adds to misery, when, patient needs to adjust him self with, new body surroundings especially, with the colostomy.
Pain relief, will not only help the patient to get adjust easily to new body surrounding but also reduces the psychological and emotional disturbances.
In the present context of this special issue on colorectal diseases, I shall restrict to, the pain management in postoperative period and in colorectal malignancies.
POST OPERATIVE PAIN RELIEF
The benefits of postoperative analgesia are speedy recovery, reduction in physical and mental stress, improvement in pulmonary function, less stress on cardiac function, decreased incidence of thromboembolic complications and on top of it reduction in cost of the treatment.
The various routes of drug delivery are available such as, intramuscular; intravenous, epidural, intrathecal, nasal, rectal and through infusion pumps.
Modalities of pain relief are as follows
Medications - There are several group of drugs available which, include NSAIDs; opioids (morphine, pethidine, fentanyl); pentazocine, local anaesthetic agents (xylocaine, sensorcaine), ketamine, buprenorphine alone or in combination with midazolam, tramadol and ketoprofen.
These medications can be given through all the above mentioned routes. The recommended dosage suggested below are for patient with ASA status I and II, and 70 kg body weight. The changes in dosage schedule should vary according to, body weight, ASA status and stability of vital signs in immediate postoperative period.
Intramuscular - Inj. Diclofenac sodium - 100 mg t.i.d.; Inj. Tramadol 100 mg t.i.d.; Inj. Pentazocine 30 mg b.i.d.
Intravenous should be started towards end of surgery or in immediate postoperative period and monitoring of vital signs is mandatory, during all the time. The drug delivery can be intravenously or by infusion pump.
The various schedules are as follows :-
1 - Inj. Tramadol 4 mg/kg or Inj. Buprenorphine 12 mcg/kg + Inj. Ondansetron 0.25 mg/kg, in 500 ml of ringer lactate @ infusion is 100 microdrops / minute for first four hours and rate should be adjusted as per degree of pain relief and stability of vital signs.
2 - Inj. Ketoprofen 100 mg in 100 ml of normal saline given over 20 minutes / 24 hours.
Intrathecal - Combination of Inj. Buprenorphine 150 mg + Inj. Midazolan 2 mg along with the required dose of Inj. Sensorcaine during spinal an aesthesia.
Intrathecal ketamine (50 mg), neostigmine (100 mg) and tramadol (25 mg) have been tried with some success.
Epidural - Inj. Bupivacaine 0.125% 10-12 ml as bolus, followed by Inj. Buprenorphine 0.006 mg/ml + Inj. Bupivacaine 0.1% in 50 ml syringe pump, @ of 4-5 ml/hr.
Nasal - Buprenorphine 0.15 mg - 0.3 has been used with some success.
Rectal - The voveran suppository t.i.d. can be used.
Infusion pump - 1-Inj. Tramadol + Phenargan + Ondansetron. - Bolus Inj. Tramadol i.v. 50 mg + Inj. Phenargan 0.5 mg/kg. Then in, infusion pump with 50 ml syringe Inj. Tramadol 1 mg/ml and Inj. Ondansetron 0.25 mg/ml, @ 1 to 1.5 ml/hour.
2-Inj. Fentanyl 1 mg/kg + Inj. Ondansetron 0.25 gm/ml @ 1 to 1.5 ml/hour.
PAIN MANAGEMENT IN COLORECTAL MALIGNANCIES
The modalities of pain relief can be classified in two headings non-invasive and invasive.
Non invasive modalities - It includes drugs and the various groups of drugs are analgesics (non-narcotic and narcotic), antidepressants, NSAIDs. The routes used are oral, transdermal, subcutaneous, intramuscular, intravenous, epidural, intrathecal and implantable devices. The management includes total patient care.
Non-narcotic analgesic- Pracetamol 500 mg t.i.d.
Narcotic - Codeine 30-60 mg t.i.d.; Dihydrocodine 30 to 60 mg t.i.d.; Morphine solution (Rilimorph) 5-10 mg t.i.d.; Morcontin 30 mg, b.i.d.; Morphine sulphate - 20 mg t.i.d.; Fortagesic 1 - t.i.d.
Antidepressants - Tab. Amitryptilline 10 mg at h.s. Tab. Alprazolam 0.25 - 0.5 mg at h.s.
Along with above medications mild laxatives or at times enema may be needed.
Transdermal fentanyl - Fentanyl patches are available in 25 mg, 50 mg, 75 mg and 100 mg. The one patch last for about seventy hours. However the titration of morphine requirement is necessary before starting of fentanyl patches. The close monitoring of vital signs for first seventy hours is mandatory.
Invasive modalities - These are mainly divided into two groups. Nerve blocks and implantable devices.
Nerve blocks - The written informed consent must be obtained before performing any neurolytic block, and preferably all the blocks should be performed under fluoroscopy.
Sacral nerve block - Relief of pain from pelvic or rectal neoplasm may involve the loss of bowel and bladder function. As second and third sacral roots are responsible for maintenance of bladder and bowel function so blocking of these roots should be avoided. Inj. Aqueous phenol 6% 1-2 ml in to 4th sacral foramen will give long-term pain relief.
Intarathecal neurolysis - The neurolytic agents used are aqueous phenol 1 ml/dermatome or absolute alcohol 1 ml per dermatome is the suggested doses. The use of fluoroscopy, positioning of the patient during injection of phenol (affected side down) and for alcohol (affected side up) is mandatory. Lumbar block is useful in some of the cases of colorectal malignancies.
Saddle block - the neurolysis by Inj. Phenol in glycerin 6% is helpful in relief of pain due to perennial malignancy.
Lumbar sympathetic block - unilateral sympathetic block with Inj. 10% phenol in oil 10 ml gives good pain relief.
Superior hypogastric block - Inj. Aqueous phe nol 1-2 ml or Inj. Absolute alcohol 1-2 ml is useful in relief of pain due to colorectal malignancy. The use of nerve stimulator is mandatory, before injecting the neurolytic drug.
IMPLANTABLE DEVICES
Implantable pump - In this electronic pump is fitted in the abdominal wall and an intrathecal catheter is tunneled under the skin and connected to the pump. The morphine is injected into the pump; the drug is delivered intrathecally continuously. The drug is injected in to the pump at regular intervals.
Epidural catheter - An epidural catheter is introduced in to the lumbar epidural space and injectable port is tunneled through the skin and brought out over the abdominal wall. The drug is injected in to the epidurally through infusion pump.
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