Summary

Background and objective: The tunnelling phase of ventriculoperitoneal shunt insertion is the most painful part but patients are often given inadequate opioid analgesic for fear of post operative delayed recovery and/or respiratory depression. This may result in an increase in intracranial pressure. Methods: Twenty adults scheduled to undergo ventriculoperitoneal shunt insertion were administered standard anaesthesia. Monitoring included heart rate, electrocardiogram, end-tidal carbon dioxide, invasive blood pressure, and oxygen saturation. Intracranial pressure was monitored by placing the ventricular end of shunt catheter in the dilated lateral ventricle. Five minutes before tunnelling, fentanyl 1 μg kg−1 was administered. Mean arterial pressure, heart rate and intracranial pressure were recorded during tunnelling and subsequently at 1-min interval for 5 min. Data were analysed using t-test and repeated measured test. Results: Tunnelling caused significant increase in mean arterial pressure (from 81.4 ± 11.0 to 110.9 ± 15.3 mmHg, P < 0.05), intracranial pressure (from 21.4 ± 8.1 to 29.2 ± 12.5 mmHg, P < 0.05) and heart rate (from 74.4 ± 13.8 to 94.1 ± 17.8 beats min−1, P < 0.05). Whereas, the increase in haemodynamic parameters persisted for 3 min post-tunnelling, elevated intracranial pressure lasted for 2 min. Conclusion: Tunnelling significantly increases intracranial pressure and blood pressure despite prior fentanyl administration. This may be deleterious in the presence of intracranial pathology.

Summary

Background and objective: Transurethral prostatectomy is routinely performed under spinal anaesthesia. This technique can cause hypotension, which is particularly undesirable in the elderly. The objective was to compare spinal anaesthesia for transurethral prostatectomy using hyperbaric bupivacaine 15 mg (control group) and hyperbaric bupivacaine 10 mg (limiting spread by maintaining the upright position for 15 min) and fentanyl 25 μg (fentanyl group) in terms of haemodynamic and pulmonary function.

Methods: Thirty ASA I–III patients were randomly selected and underwent spinal anaesthesia with either hyperbaric bupivacaine 15 mg (immediately positioned supine) or hyperbaric bupivacaine 10 mg (upright for 15 min) and fentanyl 25 μg.

Results: The greatest changes in mean arterial pressure (P = 0.9), ephedrine requirements (P = 0.8) and mean maximum change in forced vital capacity (P = 0.5) were similar in both groups.

Conclusions: The addition of fentanyl 25 μg to bupivacaine 10 mg and limiting the spread of the block does not improve either haemodynamic or pulmonary function compared with bupivacaine 15 mg in patients undergoing transurethral prostatectomy.