Sick sinus syndrome manifest after spinal anaesthesia

A case of sick sinus syndrome which presented as a cardiac arrest following spinal anaesthesia is reported. The diagnosis of sick sinus syndrome, the cardiovascular effects of spinal anaesthesia and the anaesthetic management of patients with the syndrome are discussed.     

Transient hearing loss following spinal anaesthesia

Audiograms were performed pre-operatively in 14 patients scheduled for transurethral resection of the prostate under spinal anaesthesia and again 2 days postoperatively. Six of the 14 patients showed a minor reduction of hearing in the low frequency range. Follow-up audiograms showed full recovery after 1-7 months. No significant hearing loss was found in 12 patients who underwent the same procedure with epidural anaesthesia.     

Visual disturbances after spinal anaesthesia

A complication in two female patients after spinal anaesthesia for Caesarean section is outlined. Both patients acquired permanent visual disturbances caused by pericentral ring scotomata, a condition not described before.     

Effect of epidural block on the lag time of pulse oximeter response

Thirty-six healthy patients, ASA 1, aged 16–41 years, scheduled for elective plastic surgery were studied to determine if thoracocervical or lumbar epidural blocks affected the lag time of the pulse oximeter response. Patients were allocated to receive thoracocervical epidural block (n = 20) (group 1) (lignocaine 1 %) or lumbar epidural block (n = 16) (group 2) (lignocaine 1.5%). Epidural block was performed with a 17-gauge Tuohy needle inserted in the midline between C₇-T₂ vertebrae in group 1 and between L₃-S₁ in group 2 and an epidural catheter was introduced. Arterial oxygen saturation (Spo₂) was measured continuously using a Datex pulse oximeter. The lag time of the pulse oximeter response was measured while breathing oxygen (100%) after breath-holding. Values were obtained 10min before and 5, 10, 15, 20, 30, and 40 min after epidural injection of a test dose. There was a progressive decrease in the lag time of the pulse oximeter response so that by 30 min after epidural injection the mean (SD) value had decreased from 29 (6.1) to 14 (3.4) in Group 1 and 41 (12.8) to 23 (7.9) s in group 2 (p < 0.01).     

Vasovagal asystole during spinal anaesthesia

A patient in whom vasovagal asystole was induced by the performance of a spinal anaesthetic in the upright position is described. This illustrates the importance of routine monitoring of the electrocardiograph during regional anaesthesia. The risk of vasovagal syncope may be increased by the use of the sitting position and by the omission of anxiolytic premedication.     

Mental function and morbidity after acute hip surgery during spinal and general anaesthesia

Forty elderly patients (mean age 78.9 years) undergoing acute surgery for hip fracture were given at random either spinal analgesia with bupivacaine 0.75% or general anaesthesia with diazepam, fentanly and N2O/O2. Mental function was studied pre-operatively with an abbreviated mental test and 1 week and 3 months postoperatively in both groups. Mortality and number of complications was similar in the two groups, but a shorter time of ambulation was seen in the spinal group compared to the general anaesthetic group. No persistent impairment in mental function was found after acute hip surgery under spinal or general anaesthesia and the only advantage of regional technique was a shorter time of ambulation.     

Respiratory effects of spinal anaesthesia for Caesarean section

We report the changes observed in a number of pulmonary function tests performed on 36 patients undergoing Caesarean section under spinal anaesthesia. The tests comprised peak expiratory flow, forced expiratory volume in one second, forced vital capacity, forced expiratory volume in one second to forced vital capacity ratio and the maximal mid-expiratory flow. Significant changes occurred that are consistent with a restrictive ventilatory defect. These changes persisted for four hours after the induction of spinal anaesthesia. Administration of 35% oxygen by facemask failed to change significantly fetal umbilical vein pH or partial pressure of oxygen.     

Pruritus following spinal anaesthesia

A case report of severe pruritus following spinal anaesthesia in an 80-year-old man is presented. The pathophysiology of pruritus is discussed and the possible causes in the case reported are outlined.     

Failed extradural anaesthesia for Caesarean section. Complication of subsequent spinal block

Two cases of unexpected high spinal anaesthesia following failed extradural anaesthesia for Caesarean section are described. In both cases rapid and unexpected advance of blockade, after the subarachnoid injection of moderate doses of local anaesthetic, required tracheal intubation. In one of the cases 15 ml of 0.9% saline, but no local anaesthetic, had been injected into the extradural space, suggesting that the mechanism involved is the cephalad displacement of the cerebrospinal fluid by extradural fluid, and not leakage of extradural anaesthetic solution into the subarachnoid space.     

Combined epidural/spinal anaesthesia for Caesarean section

An evaluation of a 30 gauge spinal needle in a combined epidural/spinal anaesthetic technique for Caesarean section revealed a 25% failure rate of the spinal element. In this unit, no more than 4% of spinal anaesthetics might be expected to fail. One of the reasons for the higher failure rate was that, when using the Tuohy needle as an introducer, the dura was not identified. This prompted us to compare the 'through-the-Tuohy' or needle within needle approach for combined epidural/spinal anaesthesia, with a technique that involved siting the epidural and spinal sequentially in separate spaces. One hundred women requiring elective Caesarean section under spinal anaesthesia were randomised into single or double space groups. The technique failed in 16% of through-the-needle cases, and in 4% of sequential sitings. Combined spinal/epidural anaesthesia for Caesarean section is more successful if each procedure is performed using separate spaces.     

Incremental spinal anaesthesia using a 32-gauge catheter

Incremental spinal anaesthesia using a 32-gauge intrathecal catheter was studied in 13 males scheduled for transurethral resection of the prostate or repair of inguinal hernia. The spinal technique failed in four patients. Dose-response curves were obtained in the remaining nine patients using increments of 0.5% plain bupivacaine. The spinal block was extended safely and reliably without cardiovascular instability. No patient had any postoperative headache and all catheters were removed intact.     

Comparison of continuous spinal and continuous epidural anaesthesia for lower limb surgery in elderly patients A retrospective study

This retrospective study compared continuous spinal anaesthesia with continuous epidural anaesthesia for lower limb orthopaedic surgery in the elderly. The anaesthetic records of 457 patients who received continuous spinal anaesthesia and 274 who received continuous epidural anaesthesia over a 5-year period were analysed. The patients who had continuous spinal anaesthesia were at a higher anaesthetic risk (ASA 3-4, 76% as compared with 37%, p less than 0.001), but the incidence of failures was significantly lower (1.7%, as compared with 9%, p less than 0.001) and fewer patients showed a decrease in mean arterial pressure of more than 30% (44%, as compared with 65%, p less than 0.001) and (or) received vasopressors (65%, as compared with 77%, p less than 0.01). Our data show continuous spinal anaesthesia to be more reliable and to provide better cardiovascular stability.     

Critical incidents detected by pulse oximetry during anaesthesia

Anaesthetists’ Society, Calgary, Alberta. The Critical Incident Technique was used to study anaesthetics given in a major tertiary care teaching hospital in order to define indications for monitoring with a pulse oximeter during anaesthesia. Anaesthetists were asked to use a pulse oximeter in every case and trained to report Critical incidents in order to determine if the oximeter can shorten the time to detection of these events. Four thousand seven hundred and ninety-seven anaesthetics were given during a four-month period in 1986-87. A Critical Incident was recorded when an unexpected physiologic deterioration requiring intervention by the anaesthetist to prevent a likely bad outcome was signalled first by the pulse oximeter. Critical Incidents were classified by patient characteristics, physiologic change, type of anaesthetic, and the type, length, and place of surgery. Reports were received in 65 per cent of cases, and a Critical Incident occurred in 191 (six per cent) of these. Desaturation was the commonest physiologic change (151) and was further classified as to severity (mild 85 -94 per cent saturation, moderate 75-84 percent, and severe 75 per cent). Desaturations during the maintenance phase of anaesthesia were milder but more frequent than those in the induction or emergence phases. There were no severe desaturations in elderly patients or those receiving regional anaesthesia. No group was free of Critical Incidents. Since undetected hypoxaemia may lead to disastrous complications we recommend that a pulse oximeter be used for every anaesthetic.     

Home-readiness after spinal anaesthesia with small doses of hyperbaric 0.5% bupivacaine

Fifty-four patients were studied prospectively to evaluate home-readiness after a small dose (1 or 2 ml) of subarachnoid hyperbaric 0.5% bupivacaine. The block regressed significantly earlier in the 1 ml group than in the 2 ml group (p < 0.05). The patients were also able to walk significantly earlier in the 1 ml group (median 161 min and 231 min in the 1 ml and 2 ml groups, respectively) (p < 0.05). However, there were no significant differences between the groups in time of ability to void. We conclude that adequate surgical anaesthesia can be achieved with small doses of hyperbaric bupivacaine used for spinal anaesthesia. Although the sensory and motor block after 1 or 2 ml hyperbaric bupivacaine recovered within a reasonable time for day-case surgery, in some patients recovery of the ability to void was delayed to an undesirable extent.     

The effect of epidural opioids on maternal oxygenation during labour and delivery

The effects of epidural fentanyl on the incidence of maternal hypoxaemia during labour and on neonatal welfare were examined. Women were randomly allocated to receive one of two epidural infusions, bupivacaine 0.125% alone or bupivacaine 0.0625% with 2.5 μg.ml⁻¹ fentanyl, and maternal arterial oxygen saturation was monitored continuously until delivery. The median incidence of desaturation (Spo₂ < 95%) during the active phase of the second stage of labour was significantly greater in the fentanyl group than in controls (2.9 versus 0.6 min.h⁻¹, p = 0.02). Similarly, the incidence ofdesaturation to Spo₂ < 90% was greater in the fentanyl group than in controls (p = 0.02). There was no correlation between maternal oxygenation or plasma fentanyl concentration and neonatal welfare as measured by umbilical arterial and venous blood gas and acid base status. Apgar score and Neurologic and Adaptive Capacity Score.     

Phantom limb pain during spinal anaesthesia

Phantom limb pain following amputation is a well known but comparatively rare phenomenon. Spinal anaesthesia in amputees may cause reappearance of phantom pain in previously pain-free patients despite complete sensory analgesia. Two such cases are described.