Response to Comments: Anaesthetic management of a patient with amyotrophic lateral sclerosis for transurethral resection of bladder tumour.

Sir,

We thank Adriano BS Hobaika and Artur Palhares Neto for their interest in our article and for echoing our thoughts.[12] We have stated that the use of neuraxial blockade is relatively contraindicated and that the mechanism by which neuraxial anaesthesia may cause disease exacerbation is unknown. However, we have also listed out potential mechanisms, which are hypothesised to cause spinal cord injury.

The incidence of needle trauma leading to neurologic sequelae in the general population is extremely rare.[3] It has been suggested that patients with pre-existing neurologic compromise are theoretically at a higher risk.[4] However, it has also been noted that progressive neurologic diseases worsen post-operatively, independent of the anaesthetic method.[5] Therefore avoiding regional anaesthesia is only a very conservative and legally safe approach. As many case reports are available on successful management of these patients under neuraxial block, so there are of management under general anaesthesia (GA).[6789] Most of the problems with GA arise from the disease state's abnormal drug interaction with muscle relaxants. Avoidance of these usually is associated with a smooth outcome after GA. However, as pointed out GA is not without its risks. Patients with bulbar involvement can have post-operative aspiration. Our patient was specifically noted to have no bulbar involvement.

We are not advocating the choice of one modality over another. Through our article we highlight the different options available and the pros and cons of each. We also aim to bring out the fact that use of a peripheral nerve blockade when possible could minimise the potential effects of local anaesthetics on the spinal cord.

It is difficult to determine the definite risk of any one mode of anaesthesia because there are no randomised controlled trials and available literature mostly is of individual case reports. It is also worthwhile to remember that most of these case reports do not mention a long-term follow-up. Therefore in the absence of definite guidelines proving or disproving any, the decision on the mode of anaesthesia to choose should be determined on a case-by-case basis after understanding the disease pattern in question, its pathophysiology and most importantly the patient's current physiologic state as we have already highlighted in concluding our article.