The metabolic and hormonal response to cataract surgery

Abstract

SummaryWe studied the metabolic and hormonal responses of 30 elderly patients undergoing routine cataract surgery who were allocated randomly to receive either general anaesthesia, or local anaesthesia by means of either retrobulbar or peribulbar blockade. Both jorms of local anaesthesia successfuIly prevented the increases in circulating cortisol and glucose concentrations seen in those patients who received general anaesthesia, there being no significant diflerences between retrobulbar and peribulbar blockade. The results show 'that the newer, and now more commonly performed peribulbar block, confers the same metabolic and hormonal stability as seen with the more traditional retrobulbar block. Key wordsAnaesthetic techniques, regional; retrobulbar, peribulbar. Hormones; cortisol. Surgery; ophthalmological.We showed in a previous study that local anaesthesia given by retrobulbar blockade inhibited the endocrine, and markedly reduced the metabolic, changes occurring in patients undergoing cataract surgery with general anaesthesia [I]. Today, retrobulbar block is less commonly performed, as peribulbar blockade is becoming the technique of choice. In peribulbar blockade a larger volume of local anaesthetic is injected around the orbit of the eye at one or two injection sites, whereas in retrobulbar block a smaller volume is injected intraconally towards the ciliary ganglion [2]. Although it may take slightly longer for effect, the peribulbar block has been shown to be as effective as retrobulbar block in providing sensory blockade and akinesia [3] while serious side effects are reduced as the needle is further from the dura and major blood vessels. The object of the present study was to determine whether peribulbar block, with its anaesthetic solution placed more peripherally, is as effective as retrobulbar block in decreasing the metabolic and hormonal changes associated with cataract surgery when performed under general anaesthesia. MethodsWe studied 30 elderly patients admitted for cataract surgery. They were suitable for either general or local anaesthesia and were otherwise healthy and not receiving any medication known to interfere with the hormonal and metabolic response to surgery. The patients were allocated randomly to receive either general anaesthesia (GA), local anaesthesia by retrobulbar blockade (RB), or local anaesthesia by peribulbar blockade (PB). The nature of the study was explained to them and informed consent obtained. The study was approved by the hospital ethics committee.No premedication was given to the patients. On arrival in the anaesthetic room, a central venous catheter was introduced percutaneously through an antecubital fossa vein for collection of blood samples. A control blood sample was collected after a 10 min rest period. In the GA group, anaesthesia was induced with a sleep dose of thiopentone, the trachea intubated after the administration of vecuronium and the lungs ventilated with N,O-0, and enflurane 0.6-1 .O%. Ventilation was adjusted to maintain an end-tidal CO, tension ...

Less adrenergic activation during cataract surgery with total intravenous than with local anesthesia

“…In contrast, all evaluated parameters except for glucose were reduced markedly during propofol/alfentanil TIVA. These results differ from those reported previously ( 3, 5, 13), where cataract surgery during thiopental/enflurane anesthesia was associated with substantial adrenergic activation. Although the number of studied patients was small and included only ASA physical status 1 and 2 patients, it is apparent that local anesthesia produces the best adrenergic and hemodynamic stability during cataract surgery.…”

“…The authors concluded that “local anesthesia prevented the increase in plasma norepinephrine, epinephrine, and glucose concentrations found in those patients who received general anesthesia” ( 5). In a further study the same group compared two methods of local anesthesia: retrobulbar and peribulbar blockade ( 3). There were no significant changes in blood glucose, serum cortisol, or blood lactate concentration with either technique.…”

“…In contrast to patients given local anesthesia, Barker et al found that general anesthesia with thiopental and enflurane followed by endotracheal intubation significantly increased serum cortisol and blood glucose ( 2, 3, 13). The authors therefore concluded that “cataract surgery performed under general anesthesia results in a marked hormonal and metabolic response which can be prevented by local anesthesia alone.”…”

“…L OCAL ANESTHESIA is associated with low costs and fast postoperative recovery ( 1). Studies of Barker et al indicate that local anesthesia for cataract surgery provides a remarkable hemodynamic and metabolic stability ( 2–5). The incidence of nausea and vomiting is also markedly reduced in patients given local rather than general anesthesia ( 4).…”

Comparison of peribulbar with posterior sub-tenon′s anesthesia in cataract surgery among Nigerians

“…2 Some of its merits include ease of administration, preservation of consciousness, good postoperative analgesia, reduced stress response, early mobilization, and discharge of patients as well as minimal respiratory and cardiovascular systems complications. 2 3 4 5 Regional anesthesia has been popularized in ophthalmic surgery because of its high success rate and a wide margin of safety. 4 It ensures quicker patient recovery thereby enabling day-surgery cases and reduction in cost of surgery.…”