Introduction

Intraoperative positioning nerve injuries are largely preventable complications of an otherwise uneventful anaesthetic.We present the case of our patient who developed a brachial plexus neuropathy following a general anaesthetic in the supine position. The ASA task force recommendations to prevent neuropathies are reviewed.

Case history

A 40 year old male had undergone an endoscopic procedure for bilateral upper ureteric calculi which resulted in right sided ureteric injury.Left sided DJ stenting and right sided percutaneous nephrostomy was performed. Following this, the patient developed septicemia and acute renal failure for which he underwent four sessions of haemodialysis.He was referred to our tertiary care hospital for further management. After initial stabilization, the patient was posted for elective ureteric reconstruction (Boari’s flap) surgery.

The preoperative investigations were as follows: Hemoglobin 10gm%, Serum Creatinine 3.1, Blood urea nitrogen 52mg, Serum Sodium/Potassium:137/4.3 meq/ L. All other investigations were normal and the patient did not have any other complaints.

In the operating room, a lumbar epidural catheter was inserted under standard aseptic precautions and subsequently general anesthesia with endotracheal intubation was performed. It was then noticed that the operating table had developed a technical fault and could not be tilted in right up position and neither a break in the table could be achieved. Patient was given the operating position by placing a wedge under the right flank while he was kept supine.Both arms were placed palm up on arm boards at an angle of 60-70 degrees from his trunk, secured with straps. All pressure points were padded and head was supported with a head ring.

Patient underwent an uneventful surgical procedure.Anaesthesia was maintained with Oxygen , Nitrous oxide,Isoflurane and intermittent doses of Atracurium supplemented with epidural infusion of 0.125% Bupivacaine at 4ml/hr. Surgery lasted for 5 hours and 15 minutes with an intraoperative blood loss of 350 cc. Patient was reversed ,extubated and shifted to PACU with the epidural catheter insitu.

Immediate postoperative course was uneventful where he was given one unit of blood and intermittent epidural top ups of 0.125% Bupivacaine for analgesia. On the first postoperative day, the patient complained of difficulty in moving the right upper extremity and a tingling sensation in the arm. Anesthesiologists attending to the patient in PACU noticed an inability of the patient to lift his right arm, abduct the shoulder, flex or supinate the forearm. However, wrist downwards movements were normal. Patient was immediately started on IV Dexamethasone 8 mg TDS (given for 2 days) and Multivitamins. Neuromedicine services were consulted.

A CT Brain was performed which was normal. EMG and Nerve conduction studies confirmed a proximal neurogenic lesion at C5, C6 root of brachial plexus.Epidural catheter was removed on the third postoperative day. Power improved from Grade 0/5 to Grade 2-3/5 in deltoid, pectoral, biceps and triceps group of muscles. On day 4, patient was discharged to the ward where regular supervised physiotherapy was carried out. Patient regained a power of 4/5 grade by the 10^th postoperative day in all groups of affected muscles. Elbow movements had completely recovered, however abduction was still mildly affected.The patient was discharged home on request with an advice to continue physiotherapy at home and follow up at regular intervals.

Discussion

Analysis of the American Society of Anesthesiologists closed claims database of 1990-1999 revealed that 4183 closed claims were due to anesthesia related nerve injuries₁. Regional anesthesia was more frequently associated with nerve damage claims than general anesthesia. However, ulnar nerve injuries were more common under general anesthesia₂.

Three principal mechanisms that result in nerve injury are laceration, compression and stretching₃.Laceration is the least common whereas stretching is the most common culprit in brachial plexus injury in the perioperative setting. Proximally the brachial plexus is attached to vertebral and prevertebral fascia and distally anchored to axillary sheath.Hence it cannot slide but has to stretch when traction is placed on shoulder and neck.

Various etiologies cited for perioperative nerve injury are: neural ischaemia (prolonged hypotension, vasoconstriction or hypothermia), traumatic injury (needle and catheter placement), local anesthetic toxicity, prolonged pressure (positioning, improper cast, and dressing), and patients with preexisting neurological and systemic disorders e.g. diabetes, coagulopathies, surgical trauma and rarely infectious complications. Definite mechanism of injury is rarely determined but since patient developed neurological symptoms it is assumed that something must have gone wrong or done incorrectly according to the doctrine of res ipsa loquitor(thing speaks for itself)

Many cases of brachial plexus injury associated with median sternotomy₄₅, lateral decubitus₆₇ and prone position₈ have been reported. Ours was a case where patient despite being in supine position developed postoperative neuropathy.A similar case of brachial plexus injury in supine position has been mentioned which occurred due to unexpected movement of the patient during recovery from anesthesia while his hands were strapped₉.

Fortunately prognosis of perioperative brachial plexus injury is good and conservative treatment is the main stay.Paralysed muscles should not be overstretched, whereas activity of opposing muscles and joint movements should be permitted.Knowledge and prevention are best treatments.

ASA formed a task force to advise regarding prevention of perioperative nerve injury and the summary of consensus was₁₀

Preoperative assessment

Upper extremity positioning

Protective padding

Equipment

Postoperative assessment

Documentation

Conclusion

This case highlights the need for careful positioning of every patient on the operation table which should be accompanied by periodic rechecks of position in long duration surgeries. Prevention starts from the preoperative visit and prompt intervention should be done if any new neurodeficit is seen postoperatively Complications, though rare, may be devastating for the patient.

Correspondence to

Dr. Nandini Dave C-303, Presidential Towers, L B S Marg, Ghatkopar West, Mumbai-400 086. E mail: nandini_dave@rediffmail.com