Intrathecal anaesthesia for day-case knee arthroscopy 2

Abstract

Sahni et al. make very sensible points about the use of spinal anaesthesia for day-case knee arthroscopy 1, in light of Ambrosoli et al.'s paper 2. As a past President of Regional Anaesthesia UK, I am very keen to promote the use of regional anaesthesia. However, I do not promote regional anaesthesia where I feel that the risk/benefit is, in general, not in favour of the technique. Most patients having day-case knee arthroscopy are young and fit. They present a minimal risk for general anaesthesia and local anaesthetic infiltration into the joint, which results in excellent postoperative analgesia and rapid uncomplicated discharge from hospital. The alternative of having two needles, one in the hand and one in the back, with the associated risks of painful insertion, intra-operative discomfort or even pain (because of the low dose or short acting techniques required), postdural puncture headache, falls, urinary retention, hypotension, neuropraxia, paralysis and even cardiac arrest and death, does not bear rational comparison, other than in exceptional circumstances. For these reasons, I would not consent for a spinal anaesthetic for day case knee arthroscopy myself, or a peripheral regional anaesthesia technique, and I would therefore be surprised if more than a very few properly informed, rational ASA 1/2 patients would do so either. The facts that so many patients do consent for these techniques as described in the numerous publications, and do so routinely in many institutions, makes me question the validity of the consent processes employed. There are reputably financial advantages in promoting theatre efficiency, but even these are questionable. Spinal anaesthesia has a 5% failure rate. This means that up to 1 in 20 patients will either have a prolonged spinal induction followed by conversion to general anaesthesia, or intra-operative conversion to general anaesthesia. Every time this happens, all the efficiency advantages are lost. General anaesthesia fails far less frequently in this patient group and induction takes < 5 min. The fact that patients receiving general anaesthesia spend a few more minutes in recovery is irrelevant to theatre turnover, as this time is not a limiting factor. Even if there are financial advantages, for example by using a block room to get round the former problems, I have grave doubts that this justifies the means. Spinal anaesthesia is a very useful technique and the indications for its use in ambulatory surgery have increased hugely with newer shorter-acting agents. This has undoubtedly allowed many more patients to benefit from day surgery and there will still be several fit young patients who will choose it, even when rational and fully informed. However, it is inappropriate to use it indiscriminately for the majority, just as it is unreasonable to use any single anaesthetic technique for everyone. Patients must be given a fully informed choice of the options available and that choice must be respected.