Procedural Complications of Spinal Anaesthesia in the Obese Patient

Background. Complications of spinal anaesthesia (SpA) range between 1 and 17%. Habitus and operator experience may play a pivotal role, but only sparse data is available to substantiate this claim. Methods. 161 patients were prospectively enrolled. Data such as spread of block, duration of puncture, number of trials, any complication, operator experience, haemodynamic parameters, was recorded and anatomical patient habitus assessed. Results. Data from 154 patients were analyzed. Success rate of SpA in the group of young trainees was 72% versus 100% in the group of consultants. Trainees succeeded in patients with a normal habitus in 83.3% of cases versus 41.3% when patients had a difficult anatomy ( ). SpA in obese patients (BMI ≥ 32) was associated with a significantly longer duration of puncture, an increased failure ratio when performed by trainees (almost 50%), and an increased number of bloody punctures. Discussion. Habitus plays a pivotal role for SpA efficiency. In patients with obscured landmarks, failure ratio in unexperienced operators is high. Hence, patient prescreening as well as adequate choice of operators may be beneficial for the success rate of SpA and contribute to less complications and better patient and trainee satisfaction. 1. Background Ever since the introduction of spinal anaesthesia more than a century ago, complications have been part of the technique; failed or insufficient block, headaches, nausea, vomiting, and pain around the injection site are common minor complications [1, 2]. The technique of spinal anaesthesia (SpA) is considered a basic skill, however, one that first has to be mastered. According to literature, the incidence of failed or partially failed SpA ranges between 0.5 and 17% [3–5]. The incidence of postdural puncture headaches (PDPHs) ranges between 0,7 and 11% based on the type of needle used [6, 7], and transient neurologic syndromes can still be observed after SpA with an incidence of 0–7% [8]. As with many other procedures in medicine, intuition suggests that procedure-specific experience of the operator should be beneficial and reduce complications. However, there is only sparse data available to demonstrate that this is the case for SpA [9, 10]. Furthermore, with an increasing number of severely obese patients in western society, anesthesiologists are—more than ever—faced with patients where the individual habitus causes a challenge to perform a seemingly simple basic skill like SpA because it relies on identifiable anatomical structures termed “landmarks.” These can be completely obscured in the obese