Pancuronium, vecuronium, and heart rate during anesthesia for aortocoronary bypass operations.

To determine the effects of pancuronium and vecuronium on heart rate, 90 patients scheduled for aortocoronary bypass were randomly assigned to one of three groups (30 patients each) which received vecuronium 100 micrograms[sdot]kg-1, pancuronium 100 micrograms[sdot]kg-1, or a mixture of vecuronium (50 micrograms[sdot]kg-1) and pancuronium (50 micrograms[dot]kg-1) in a double-blind fashion during induction of anesthesia. All patients were premedicated with lorazepam prior to surgery, hence avoiding the effects of scopolamine. Our results showed no significant increase in heart rate from the administration of pancuronium, following administration of this drug the heart rate increased by only four beats per minute. The heart rate was unchanged after the mixture, but decreased by twelve beats per minute after vecuronium (P < 0.05). The heart rate response differed by 16 beats per minute between pancuronium and vecuronium. All patients who received either of the neuromuscular relaxants and who were on beta blockers showed a decrease in heart rate. In this study, the administration of pancuronium after an adequate induction dose of fentanyl did not cause tachycardia. We therefore feel that pancuronium still has a role in cardiac anesthesia, especially as the newer muscle relaxants such as vecuronium, pipecuronium and doxacurium are significantly more expensive.

Anaesthetic implications of 32% Dextran-70 (Hyskon) during hysteroscopy: hysteroscopy syndrome.

This review describes the properties and side effects of Hyskon and the implications for the patient and anaesthetist during hysteroscopy. The amount of Hyskon absorbed is dependent on the injection pressure, the extent of tissue trauma, the seal of the hysteroscope around the cervix, and the duration of infusion. The mechanism of pulmonary oedema after absorbtion of Hyskon is fluid overload, and not injury to pulmonary capillary endothelium. The haematological effects are primarily due to haemodilution. However, case reports suggest that Dextran 70 may cause a syndrome resembling disseminated intravascular coagulation. The allergic response to Hyskon consists of both an anaphylactic and an anaphylactoid component. It is recommended that hysteroscopy with Hyskon be limited to 45 min, and that all possible measures be taken to minimize tissue trauma and bleeding. The volume of Hyskon should be limited to less than 500 ml, since pulmonary oedema and coagulopathy have been described with even lesser amounts. The cumulative volume of Hyskon should be monitored frequently and the patient should be closely monitored for signs of impending pulmonary oedema.