Comparison of PCNL under spinal versus general anaesthesia
Reviewed by Adam Alleemudder

There are several advantages of performing percutaneous nephrolithotomy (PCNL) under spinal anaesthesia including lower cost, reduced adverse effects and less tracheal tube displacement. Another advantage is that the patient remains awake throughout making positioning easier and reducing the risk of untoward neurological effects caused by excessive head rotation or extension. This prospective study from Iran aimed to determine whether spinal anaesthesia could provide additional benefit of reducing postoperative analgesia requirements. All 100 patients in the study with American Society of Anesthesiologists (ASA) scores <3 were evenly matched in terms of age, stone location and burden and were split equally into two groups to receive either spinal or general anaesthesia. Inclusion criteria were stones >2cm, age >16 years and negative urine cultures. Those in the general anaesthesia group received what appears to be the standard cocktail of drugs used on a regular basis for any procedure whilst those in the spinal anaesthetic group received an injection of 0.25mg/kg bupivacaine 0.5% in the intrathecal space. All procedures were performed prone and all patients received patient-controlled analgesia (PCA) (1mg/kg morphine in every 100mL physiologic saline) during the first three hours in the recovery ward. From 3 to 24 hours the opioid requirement was monitored using intramuscular morphine 0.05mg/kg when the verbal pain score was >3. The mean hospital stay, operative time, stone-free rate and haemoglobin drop were comparable between the two groups. The mean analgesic requirement during the first 24 hours however was much less in the spinal anaesthetic group (6.8mg vs. 13.2mg). This type of study to highlight the benefits of spinal anaesthesia is not new and several studies have previously been published including those by Ballestrazzi (1988), Said (1991) and Attalah (2006). Whilst the advantages of regional anaesthesia are again highlighted, the authors make no effort in defining the reasons for the observed reduction in analgesic requirements compared to general anaesthesia. 

Comparison of percutaneous nephrolithotomy under spinal versus general anesthesia: a randomized clinical trial.
Nouralizadeh A, Ziaee S, Sharifi S, et al.
JOURNAL OF ENDOUROLOGY
2013;27(8):974–8.