SummaryA double-blind, randomised clinical study was undertaken to compare the efSect of temperature on the incidence and severity of the pain experienced on injection of propofol. The number of patients who experienced pain and the severity of the pain were reduced signijicantly when propofol was administered at a temperature of 4°C. The eficacy of propofol as an induction agent appeared to remain unaltered. Key wordsAnaesthetics, intravenous; propofol. Complications; pain.It is well recognised that propofol may cause pain or discomfort on injection when administered intravenously, especially into a vein on the dorsum of the hand. Studies have shown that the incidence may be as high as 45%.' Premedication has little influence on the incidence of pain but may reduce its severity.2 Other important factors are known to be the site and speed of injection3-' and the use of analgesics and local anaesthetics in combination with p r o p o f~l .~-~ This study was designed to assess whether the temperature of propofol affects the incidence or severity of pain on injection. Patients and methodsThe study was performed on 71 adult patients of ASA class 1 and weight 50-85 kg who presented for minor, elective surgery. Informed consent was obtained. All patients received lorazepam 0.5 mg/lO kg to a maximum of 4 mg, 90 minutes before surgery. A 22-gauge cannula was inserted into the largest apparent vein in the dorsum of the hand. The patients were then allocated randomly to one of two groups.General anaesthesia was induced with intravenous propofol 2.5 mg/kg. Patients in group 1 received propofol that had been taken directly from the refrigerator (4-5°C). Those in group 2 received propofol maintained at room temperature (20-23°C). The speed of injection was controlled carefully. One quarter of the total calculated dose was given over the first 5 seconds; after this period, the injection was stopped for 5 seconds to allow assessment of discomfort by the method outlined below. An initial pain score was obtained. Induction was then continued and the second quarter of the total induction dose was administered over a further 5-second period. The patient was questioned again and a second pain score obtained. Finally, the remainder of the induction dose was administered.The level of pain was assessed by a second, independent anaesthetist who was unaware of the group to which the patient had been allocated. The pain score was obtained by asking the patient a standard question about the comfort of the injection and the verbal response, together with behavioural signs such as facial grimacing, arm withdrawal or tears. A score of 0 to 3, which corresponded to no pain, mild, moderate and severe pain, respectively, was recorded ( Table 1). ResultsThe second pain score was higher in all cases and this score was used for later analysis. The results are shown in Table 2. The overall incidence of pain in group 2 was 46% compared with 23% in group 1 (p < 0.05). In addition, less patients in group 1 experienced severe pain (3% versus 21 Yo; p <...

Interruption of agitation of PCs for 1 day, either on the agitator or in the shipping container, produces no platelet damage measurable by these in vitro techniques. However, an interruption of agitation for 2 days can result in significant damage in some components. Further studies will be required to learn more about the mechanisms that lead to the metabolic changes described and to determine if the same generalizations apply to apheresis PCs and PCs prepared from pooled buffy coats.

We studied 160 ASA I-II patients, anaesthetized with propofol by infusion, using either a manually controlled or target-controlled infusion system. Patients were anaesthetized by eight consultant anaesthetists who had little or no previous experience of the use of propofol by infusion. In addition to propofol, patients received temazepam premedication, a single dose of fentanyl and 67% nitrous oxide in oxygen. Each consultant anaesthetized 10 patients in sequential fashion with each system. Use of the target-controlled infusion resulted in more rapid induction of anaesthesia and allowed earlier insertion of a laryngeal mask airway. There was a tendency towards less movement in response to the initial surgical stimulus and significantly less movement during the remainder of surgery. Significantly more propofol was administered during both induction and maintenance of anaesthesia with the target-controlled system. This was associated with significantly increased end-tidal carbon dioxide measurements during the middle period of maintenance only, but recovery from anaesthesia was not significantly prolonged in the target-controlled group. With the exception of a clinically insignificant difference in heart rate, haemodynamic variables were similar in the two groups. Six of the eight anaesthetists found the target-controlled system easier to use, and seven would use the target-controlled system in preference to a manually controlled infusion. Anaesthetists without prior experience of propofol infusion anaesthesia quickly became familiar with both manual and target-controlled techniques, and expressed a clear preference for the target-controlled system.

ESC and HSR test results are significantly affected by the test diluent. Platelets should be diluted in plasma (preferably autologous) for the in vitro testing of ESC and HSR, regardless of the media in which they are stored.

Goulian and Watson knives work well for tangential burn excision on large flat areas. They do not work well in small areas and in areas with a three-dimensional structure. The Versajet Hydrosurgery System (Smith and Nephew, Key Largo, FL) is a new waterjet-powered surgical tool designed for wound excision. The small size of the cutting nozzle and the ability to easily maneuver the water dissector into small spaces makes it a potentially useful tool for excision of burns of the eyelids, digits and web spaces. The Versajet Hydrosurgery System contains a power console that propels saline through a handheld cutting device. This stream of pressurized saline functions as a knife. We have used the Versajet for burn excision in 44 patients. Although there is a learning curve for both surgeons using and operating room staff setting up the device, the Versajet provides a relatively facile method for excision of challenging aesthetic and functional areas.