Spinal Anaesthesia, with Special Reference to Neurological Complications

Sinclair, Robert Nelson (1953) Spinal Anaesthesia, with Special Reference to Neurological Complications. MD thesis, University of Glasgow.

Abstract

The studies reported in this thesis were undertaken because the author believed that the merits of spinal anaesthesia were being obscured by prejudice, and that a reassessment of the method was indicated. Consideration of the history of spinal anaesthesia, with the earlier reckless use of imperfect techniques, explains in part the persistence of distrust of the method. A survey of the literature revealed many clinical reports of serious neurological complications following spinal anaesthesia, but critical study of these reports showed that many were of doubtful value and could largely be discredited because either the details of administration were not divulged or the technique was at fault. The relevant Anatomy, physiology and Pharmacology is discussed. Experimental proof is quoted that the incidence of cauda equina lesions in cats is in direct proportion to the concentration of the anaesthetic solution. Stovaine was shown to be a damaging drug. The nature of neurological lesions after spinal anaesthesia, both experimental and clinical, is studied, of which a cauda equina lesion is the most common. The damage to the nervous tissues is directly due to a neurotoxic effect of the anaesthetic drug. Reports of histological examinations showed that the changes were mainly in the nerve roots and in the periphery of the cord. These changes consisted of swelling and fragmentation of the axis cylinders and degeneration of the myelin sheaths. There was also a meningeal reaction with leucocytic infiltration, which reaction may proceed to fibrosis. The development of spinal anaesthetic practice is traced, showing its evolution and the continuous improvements in technique. The use of covering anaesthesia, for example, has removed a previous objection to the method, without loss of any of its advantages. The rationale of total sympathetic block is set forth. It is not uncommon to find a vague, subconscious disquietude concerning spinal anaesthesia, and this is reflected in the opinions expressed to the writer by the Nursing Staff, and given in the text, although the general impression is favourable. The methods of sterilisation are reviewed and medicolegal aspects of meningitis following spinal anaesthesia discussed. The author's technique of spinal anaesthesia is described in detail, and the need for scrupulous asepsis is emphasised. The use of a 0.4% isotonic solution of amethocaine was recommended. There is presented a personal series of 1335 spinal anaesthetics. Of these patients, 536 were examined in detail before their departure from hospital, in order to disclose any evidence of neurological dysfunction, either overt or unsuspected, which may have been due to the spinal anaesthetic, and 76 patients were also re-examined six months to two years later, with the same purpose in view. The examination included a careful enquiry for headache, diplopia, retention of urine, incontinence of faeces, paraesthesiae and weakness of the lower limbs. Sensation was tested in the legs and sacral area, the reflexes examined, and anal sphincter tone estimated. The results confirmed the author's belief that no neurological sequelae of any import were arising in his cases. Spinal headache was divided into three grades of severity, and it was found that very slight headache occurred in 13.2%, and moderate headache in 6%, of these cases. Severe headache was not encountered and 80.8% of the patients did not suffer from headache at all. One case of fleeting diplopia was noted, and also one case of transient leg pains which may have been due to the spinal anaesthetic. No infective meningitis occurred. A short investigation into the effects of spinal anaesthesia on the cerebrospinal fluid was undertaken. The results did not substantiate the finding, quoted frequently in the literature, that spinal anaesthesia in nearly every case produces a definite rise in the cerebrospinal fluid cell-count, due to meningeal irritation. Specimens of cerebrospinal fluid from 46 patients were examined before the spinal anaesthetic was administered, and again about 24 hours later. In only one specimen was there a marked rise in the cell-count after spinal anaesthesia (390 per c.mm.) This patient was quite symptomless and afebrile, she made an uninterrupted recovery from operation and was well when re-examined nine months later. It was concluded that spinal anaesthesia is a satisfactory method of anaesthesia and there is no need to fear neurological complications following its use. Furthermore, the concentration of the anaesthetic solution was shown to be of the greatest consequence, and it was pointed out that there is a definite low and safe level of concentration, at which uncomplicated and effective anaesthesia can be achieved and which it is unnecessary and undesirable to exceed.

• Item Type: Thesis (MD)
• Qualification Level: Doctoral
• Keywords: Medicine, Neurosciences
• Date of Award: 1953
• Depositing User: Enlighten Team
• Unique ID: glathesis:1953-79801
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 03 Mar 2020 10:34
• Last Modified: 03 Mar 2020 10:34
• URI: https://theses.gla.ac.uk/id/eprint/79801