Premedications and peribulbar analgesia--a prospective audit

After peribulbar block analgesia (PBA) instituted in the preoperative anesthetic room, patients are often anxious, developing increased heart rate (HR) and blood pressure (BP) upon their arrival to the operating room and during subsequent surgery. The efficacy of premedication in attenuating these stress responses has not been examined. A prospective audit was undertaken to examine the relationship between the premedication schedules most commonly prescribed at the King Khaled Eye Specialist Hospital and increases in HR and BP during surgery in response to the stress of surgery, and the requirements for intravenous (IV) benzodiazepine, opioid or NSAID medication to treat these increases, or any complaint of pain or positional discomfort on the operating table, respectively.

The preoperative and intraoperative anesthesia course of 1,064 patients > or = 50 years of age who underwent ocular surgery under PBA was prospectively examined. The following data were recorded: (i) patient characteristics, state of health or disease, medications and premedications; (ii) heart rate (HR), systolic arterial pressure (SAP), and diastolic arterial pressure (DAP) at 0600 hrs before surgery (baseline), on admission to the operating room, maximum and minimum values of HR, SAP and DAP recorded at the start of, and during, surgery; and (iii) all instances of benzodiazepine, opioid or NSAID drug administration during surgery, according to standard protocols.

Five premedication schedules were identified: Group 1 hydroxyzine po alone (n = 302); Group 2 hydroxyzine, paracetamol with codeine (Revacod), diclofenac po (N = 173); Group 3 hydroxyzine, diclofenac, ranitidine po (N = 94); Group 4 hydroxyzine, cimetidine or ranitidine po, morphine or pethidine IM (N = 340); and Group 5 lorazepam (nocte), hydroxyzine, diclofenac, ranitidinepo, morphine or meperidine IM (N = 155). The five groups of patients were comparable for age, sex, weight and health. Healthy, diseased (with concurrent hypertension, diabetes, ischemic heart disease) and all patients in each premedication group had similar baseline HR, SAP and DAP. In the operating room, the maximum and minimum mean HR in each group was similar, except that more patients in Group 1 developed SAP exceeding 160 mmHg and DAP exceeding 90 mmHg than in Group 5 (p<0.002 and <0.0005, respectively). The requirements for medication at the commencement of, and during, surgery in the five groups to treat increases in HR/BP, eye pain and positional discomfort on the operating table were similar.

Each of the five premedication schedules described appear to confer similar effects on cardiovascular changes in anticipation of, and during, surgery, except that those given the lightest premedication, Group 1, showed greater increases in BP at the start of surgery than did those given the heaviest premedication, Group 5. The requirements in the operating room for IV medication were similar in the five premedication groups, and no greater benefit was discernible for any one of the five premedication schedules on the objective features assessed. These data suggest that simple oral premedication of hydroxyzine, with or without an H2 receptor antagonist and NSAID, may suffice as premedication in middle-aged to elderly patients undergoing anterior segment surgery.