Spinal anaesthesia for Caesarean section in a patient with systemic sclerosis.

Abstract

We read with interest the case report by Bailey and colleagues demonstrating the successful use of spinal anaesthesia for Caesarean section in a patient with systemic sclerosis and thrombocytopenia as a manifestation of pre-eclampsia (Anaesthesia 1999; 54: 355–8). Patients with systemic sclerosis present special challenges to the anaesthetist. Because of the low prevalence of the condition, much of our knowledge regarding the anaesthetic management is based upon case reports and personal opinion rather than controlled trials. We wish to make the following comments. Microstomia as a result of fibrosis of the skin and subcutaneous tissues and limited mouth opening secondary to induration of the temporomandibular joint may result in difficult tracheal intubation in patients with systemic sclerosis. Furthermore, progressive oesophageal fibrosis often induces gastro-oesophageal reflux. In spite of this, a regional technique is by no means always preferable to general anaesthesia in patients with systemic sclerosis. We have demonstrated that a meticulous anaesthetic technique and the combined administration of prokinetic and antacid drugs before general anaesthesia in patients with systemic sclerosis reduces the incidence of regurgitation to levels near or below that of a general surgical population, even when using a laryngeal mask [1]. Systemic sclerosis is a condition that may affect a multitude of organs. Haemostatic or haemopoietic mechanisms are not normally affected. The development of thrombocytopenia as a manifestation of pre-ecclampsia has made this case report especially interesting. In their patient, the authors used a spinal in preference to an epidural technique because it was thought less likely to be a risk factor for the development of an epidural haematoma in a thrombocytopenic patient. It should not be assumed, however, that spinal anaesthesia is safe with respect to the development of a vertebral canal haematoma in a patient with a clotting disorder. In a meta-analysis including 850 000 patients undergoing central nervous blockade, the incidence of vertebral canal haematoma following epidural anaesthesia has been estimated to be 1 in 150 000 compared with 1 in 220 000 after spinal anaesthesia [2].This difference in relative risk is not sufficient to exonerate spinal anaesthesia completely. The authors suggest the use of thrombelastography to assess haemostatic function and estimate the risk of epidural haematoma formation. Indeed, thrombelastography has been shown to be a highly sensitive indicator of platelet function and platelet numbers. Both thrombocytopenia and functional impairment of platelets result in reductions of the alpha angle and the maximum amplitude [3]. New instruments have been developed recently, such as a novel platelet function analyser (Dade PFA-100TM), which we are currently evaluating [4]. Case reports are valuable in highlighting the anaesthetic difficulties associated with certain conditions and their successful management, but eventually only randomised controlled trials will determine the best possible strategies for dealing with rare and challenging conditions such as systemic sclerosis.