Radcliffe Infirmary, Oxford 1 A 10 h study of plasma drug concentrations of the opiate buprenorphine after sublingual use was designed because a previous 3 h study had shown that peak plasma drug concentrations in some patients had not occurred by 3 h after the sublingual dose. 2 Fifteen postoperative patients were studied: at 3 h after a 0.3 mg intravenous dose five patients received a sublingual preparation of 0.4 mg of buprenorphine, five 0.8 mg of buprenorphine and five placebo. Plasma drug concentrations of buprenorphine were measured by specific radioimmunoassay. 3 Plasma drug concentrations after sublingual buprenorphine were significantly higher than those in the placebo group by 1 h. They remained significantly higher over the succeeding nine hours. The mean time to peak plasma drug concentration was about 200 min in both the 0.4 mg and 0.8 mg groups (range 90-360 min). The plasma drug concentrations in the 0.8 mg group were approximately twice those in the 0.4 mg group; the ratio of the relative systemic availabilities was similarly 1.8:1. The absolute systemic availability was estimated at about 55% for both groups. Uptake of buprenorphine from the sublingual site was essentially complete by 5 h after the dose was given. 4 The implications for the timing of sublingual doses in clinical use are discussed.

SUMMARYThis study investigated the rate and degree of reduction in intraocular pressure (lOP) obtained with an external ocular compression device. Following removal of the device, the subsequent recovery in lOP was monitored. We aimed to establish the time course of lOP changes, and thereby to optimise our use of such devices prior to cataract surgery. A rapid initial reduction over the first 10 minutes of compression was followed by a more gradual reduction to a mean reduction of 6.97 mmHg at 40 minutes. Recovery of lOP was rapid and complete by 20 minutes. We conclude that compression of up to 40 minutes duration is beneficial, and suggest such devices should be left on until immediately prior to surgery to preserve the reduction achieved. MATERIAL S AND METHODSFifteen volunteers ranging in age from 22 to 80 years were used in this ethically approved study. Subjects with a history of previous intraocular surgery, uveitis, glaucoma or hypertension were excluded. Both eyes were used in the study if possible, one eye acting as a control. The eye to be subjected to compression was selected randomly. A total of 15 test eyes and 13 control eyes were used in the study.The subjects were positioned supine prior to the study From:

The effects of methadone 10 mg administered in two different clinical contexts, at induction of anaesthesia and following operation, were studied in two groups of patients undergoing elective total hip replacement. The intraoperative group received methadone 10 mg i.v. at induction of anaesthesia as part of a balanced anaesthetic technique. The postoperative group received methadone 10 mg i.v. following operation, extradural bupivacaine being used for the operative period. A demand analgesia system delivering methadone i.v. was used after operation in both groups. Arterial blood-gas tensions, cortisol and glucose concentrations, analgesic effects and plasma methadone concentrations were compared in the two groups. The only major difference between the two groups was in analgesic requirement. At the time of connection to the demand system the two groups had the same plasma methadone concentrations. Subsequently, the postoperative group had a significantly greater analgesic requirement which resulted in significantly greater plasma methadone concentrations the following morning. Thus, the administration of methadone following operation appeared to exert less analgesic effect than the same dose given during operation. The reasons for this are discussed.

SUMMARYExtraconal peribulbar local anaesthesia for ocular surgery is a common and acceptable technique for patients, surgeons and anaesthetists.1,2 It has rapidly become the preferred technique for ocular surgery in many centres, as the possible grave consequences of intraconal retrobulbar local anaesthesia, including the introduction of local anaesthetic agents into the central nervous system, have now become apparent?The technique of extraconal peri bulbar anaesthe sia requires a relatively large volume of anaesthetic solution to be injected into the peribulbar space. This space is confined by the bones of the orbit, and therefore by inference the introduction of fluid into this space should result in a pressure effect on the globe. This study was designed to assess intraocular pressure change during the induction of extraconal peribulbar anaesthesia for cataract surgery using a non-contact tonometer. PATIENTS AND METHODSInformed consent was obtained from 20 adult patients undergoing elective cataract surgery under local anaesthesia in this ethically approved study. Patients with a history of glaucoma, trauma or previous surgery to the eye were excluded.After insertion of an intravenous cannula, anaes thesia was induced following a standardised tech nique. All solutions were warmed to 37°C. First 0.5 ml amethocaine 1 % was diluted to 2 ml in balanced salt solution, and instilled into the inferior conjunctival fornix. This was followed after 15 seconds by 3 drops of undiluted amethocaine 1 % drops. Then 1.5 ml 0.2 % lignocaine (derived from dilution of 2% lignocaine in balanced salt solution) was injected through a 27 gauge 12 mm needle into the inferotemporal fornix. The eye was massaged gently by digital pressure for 1 minute and then a Buys bag (Micro-Surgical Technology, USA) was applied for 2 minutes to standardise the pressure applied.After this 3 minute period, the subsequent injec tions were commenced, using a 25 mm 25 gauge needle. Each was of 5 ml volume, and contained equal volumes (2.25 ml) of 0.75% bupivacaine and 2% lignocaine, with hyalase 37.5 IU and adrenaline 25 fLg. The first of these injections was made in the