The effects of the new, highly selective alpha 2-adrenergic agonist, dexmedetomidine, were studied in a randomized, placebo-controlled, double-blind trial in 24 ASA I patients. Dexmedetomidine 0.6 micrograms kg-1 or saline was given i.v. 10 min before induction of anaesthesia. The required dose of thiopentone was significantly (P less than 0.001) smaller in the dexmedetomidine group (mean 4.4 (sd 0.9) mg kg-1) than in the control group (6.9 (1.6) mg kg-1), and the drug attenuated the cardiovascular responses to laryngoscopy and tracheal intubation. The concentration of noradrenaline in mixed venous plasma was smaller in the dexmedetomidine group during all phases of induction (P less than 0.01). During surgery, fentanyl was required in a dose of 0.5 (0.6) mg kg-1 and 2.8 (2.6) mg kg-1 in the dexmedetomidine and control groups, respectively (P less than 0.001). During 2 h postoperative follow-up, oxycodone 0.06 (0.06) mg kg-1 and 0.16 (0.1) mg kg-1 (P less than 0.05) was given to the two groups respectively.
Both ventilation modes produced epileptiform EEG. With controlled ventilation, epileptiform discharges were seen in 88% of children. This warrants further studies of the suitability of this induction type in general, and especially in children with epilepsy.
L APAROSCOPY is ''the golden standard'' in treating symptomatic gallstones. Because the postoperative benefits are superior to open cholecystectomy, laparoscopy is today also used in patients with underlying diseases. To be able to treat this challenging patient population, we should be aware of physiological alterations caused by carbon dioxide (CO 2) insufflation and elevated intra-abdominal pressure (IAP). It is now commonly accepted that pneumoperitoneum causes intraoperative adverse cardiovascular, respiratory and renal effects. Some of these effects are related to CO 2 and some to elevated IAP. CO 2 is the preferred gas for the creation of pneumoperitoneum because it is inexpensive, highly soluble, chemically stable, rapidly eliminated, physically inert, suppresses combustion and also provides fairly good illumination. CO 2 is a normal product of human metabolism and at physiological levels non-toxic.
Sevoflurane mask induction elicits epileptiform EEG patterns. These are associated with an increase in heart rate in patients with controlled hyperventilation and also during spontaneous breathing of sevoflurane.
We have studied the haemodynamic changes, QT intervals and catecholamine responses to induction of anaesthesia and tracheal intubation in 24 ASA I patients allocated randomly to receive either propofol 2.5 mg kg-1 or thiopentone 5 mg kg-1 over 60 s. After disappearance of the eyelash reflex, the lungs were ventilated with 100% oxygen for 3 min. The trachea was intubated after administration of vecuronium. With thiopentone, heart rate (HR) was greater than with propofol before intubation (P < 0.05). During induction, systolic (SAP) and diastolic arterial pressure (DAP) decreased more with propofol than with thiopentone. The QT interval was prolonged only during induction with thiopentone. In both groups, HR, SAP, DAP and the QT were increased in response to intubation (P < 0.001). The SAP and QT interval responses to intubation were significantly greater with thiopentone than with propofol (P < 0.05). One patient in the thiopentone group with a significantly prolonged QT interval had episodes of bigeminy and ventricular tachycardia. In both groups, concentrations of noradrenaline in mixed venous plasma increased after intubation (P < 0.001). Concentrations of adrenaline increased after intubation only in the thiopentone group (P < 0.001).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.