Continuous spinal anaesthesia

CD59 is a cell membrane-bound complement regulatory protein on glomerular cells that inhibits C5b-9 assembly and insertion. This report describes a recently developed model of immune thrombotic microangiopathy (TMA) induced by the renal artery perfusion of anti-glomerular endothelial cell (anti-GEN) antibody. To examine the role of CD59 in protecting the GEN from immune-mediated injury, rats underwent selective renal artery perfusion with F(ab')2 fragments of anti-CD59 monoclonal antibody to block CD59 activity or control mouse IgG followed by anti-GEN antibody or control goat IgG. Neutralization of CD59 in normal rats did not result in any significant functional or histologic changes. Perfusion with anti-CD59 did not change deposition of the pathogenic anti-GEN IgG used to induce the TMA model. However, neutralization of CD59 in the TMA model resulted in more C5b-9 formation in glomeruli, accompanied by increased platelet and fibrin deposition, more severe endothelial injury, and reduced renal function compared with the animals perfused with control F(ab')2 fragments. These results demonstrate directly that CD59 serves a protective role for GEN in this TMA model of rats, and confirm that C5b-9 formation has a critical pathogenic role in the mediation of the disease. CD59 may play an important role in protecting glomerular endothelium from other complement-mediated types of injury.     

Physiology of spinal anaesthesia and practical suggestions for successful spinal anaesthesia

There are numerous physiological effects of spinal anaesthesia. This chapter focuses on the physiological effects that are of clinical relevance to the anaesthesiologist, and provides suggestions for successful management of this simple and popular technique. The mechanisms and clinical significance of spinal-anaesthesia-induced hypotension, bradycardia and cardiac arrest are reviewed. The increasing popularity of ambulatory spinal anaesthesia requires knowledge that long-acting local anaesthetics, such as bupivacaine, impair the ability to void far longer than short-acting local anaesthetics, such as lidocaine. The importance of thermoregulation during spinal anaesthesia, and the clinical consequences of spinal-anaesthesia-induced hypothermia are reviewed. Effects of spinal anaesthesia on ventilatory mechanics are also highlighted. Lastly, the sedative and minimum-alveolar-concentration-sparing effects of spinal anaesthesia are discussed to reinforce the need for the judicious use of sedation in the perioperative setting.     

Rebound hypertension during anaesthesia

A case of rebound hypertension under anaesthesia, following withdrawal of clonidine, is described and methods of treatment outlined.     

Outpatient haemorrhoidectomy under local anaesthesia

OBJECTIVE: To compare early and late results and costs of outpatient haemorrhoidectomy under local anaesthesia with those of inpatient haemorrhoidectomy. DESIGN: Prospective study with historical controls. SETTING: University hospital, Brazil. SUBJECTS: 51 patients who required haemorrhoidectomy. INTERVENTIONS: Outpatient haemorrhoidectomy under local anaesthesia. MAIN OUTCOME MEASURES: Early and late results and comparative costs. RESULTS: One patient was withdrawn from the study because of hypertension and subsequently lost to follow-up. The remaining 50 patients were discharged a mean of 68 (23) minutes after operation. Twelve patients complained of severe pain, one had faecal impaction and 2 developed bleeding. One patient developed urinary retention, compared with 18 in the historical group (p < 0.001). Forty-two patients (84%) were thoroughly satisfied with their treatment. Late complications did not differ significantly from those observed in the historical group. The estimated hospital costs were US$ 313.6 for outpatient, and US$ 716 for inpatient treatment. CONCLUSION: Outpatient haemorrhoidectomy under local anaesthesia was safe and comfortable for most patients, with complication rates comparable to or better than those observed after inpatient treatment and at less than half the cost.     

Leucocyte distribution during sevoflurane anaesthesia

We have examined if sevoflurane anaesthesia per se modified the number of circulating leucocytes in humans. Fifty-nine patients undergoing elective surgery were anaesthetized with sevoflurane in oxygen. The inhaled concentration was increased gradually to 5% and maintained for 20 min. Arterial blood samples were obtained before induction of anaesthesia and at 20 min. While the total number of leucocytes remained constant, circulating neutrophils decreased (mean 3370 (SD 1030) mm-3 to 3170 (940) mm-3; P < 0.01) and lymphocytes increased (1870 (520) mm-3 to 2040 (580) mm-3; P < 0.01). We conclude that high concentrations of sevoflurane modified the distribution of leucocytes in anaesthetized patients.     

Awake tracheal intubation in anaesthesia

Endotracheal intubation in the awake patient was used on 500 occasions. Indications and results are discussed and analysed.     

Liver function tests following anaesthesia

Liver function tests were performed in 41 patients who required repeated anaesthetics for genito-urinary surgery, and who had received multiple halothane anaesthetics in the past, first following anaesthesia using halothane and then following an anaesthetic without halothane. There was a smaller frequency of disturbance of liver function after halothane than after the non-halothane anaesthetic. There was no obvious relationship between the number of anaesthetics, or the total duration of anaesthesia, and the disturbance of liver function tests.     

Difficult intubation and brain-stem anaesthesia

PURPOSE: To present a case of difficult intubation with brainstem anaesthesia after retrobulbar block with bupivacaine and lidocaine and sedation with midazolam and to point out that close monitoring and timely treatment is important in preventing an unfavourable outcome. CLINICAL FEATURES: An 82-yr-old man with treated hypertension and stable angina was scheduled for cataract extraction. Physical examination revealed a class 2 airway. He had a retrobulbar block after topical tetracaine drops, with bupivacaine 0.5% and lidocaine 2% with hyaluronidase under sedation with 1 mg midazolam. Five minutes after the block, respiration slowed, he became unresponsive and oxygen saturation decreased to 80%. Immediate ventilation with mask without additional oxygen improved saturation. Attempted tracheal intubation failed: the epiglottis could not be visualized despite flaccid jaw and extremities. A laryngeal mask airway was placed which was leaking and adequate ventilation could not be achieved but a second laryngeal mask airway was placed successfully. CONCLUSION: This case emphasizes the need for dose monitoring and personnel capable of managing the difficult airway when intra-orbital anaesthesia is used.     

Peribulbar anaesthesia and needle length

This retrospective audit of 87 consecutive patients undergoing routine cataract surgery compared the effect of peribulbar local anaesthesia using 16 mm and 25 mm, 25 gauge needles to administer the anaesthetic. The effect on optic nerve function was observed. There was a significant increase of complete amaurosis in the group where the 16 mm needle had been used. This may be explained by more effective anatomic placement of the 16 mm needle within the orbit, allowing access to the retrobulbar space via fascial septae. There was significantly more lid akinesia with the 16 mm needle. None of this group required an additional facial nerve block, as opposed to 14% of the 25 mm needle group. The use of a 16 mm needle is theoretically safer than a 25 mm needle to administer a peribulbar anaesthetic, in this review it was also demonstrated to be more effective.