Anaesthesia
-
Letter Randomized Controlled Trial Clinical Trial
Sub-Tenon's block without hyaluronidase.
-
Two recent studies have examined the pharmacokinetics of sevoflurane in adults. Lu et al.(Pharmacokinetics of sevoflurane uptake into the brain and body, Anaesthesia 2003; 58: 951-6) observed that jugular bulb sevoflurane concentration initially rose unexpectedly rapidly and then approached arterial concentrations unexpectedly slowly, suggesting that a blood-brain diffusion barrier exists. They also observed a large alveolar-arterial sevoflurane gradient, suggesting that an alveolar-arterial diffusion barrier exists. ⋯ We used a computer model to analyse both data sets and show that the observations of Lu et al. can be explained by contamination of jugular samples with extracerebral blood. It is possible that the alveolar-arterial gradients observed by Lu et al. are due to discrepancies in conversions between blood concentrations and gas partial pressures. Our study suggests that there is no blood-brain diffusion barrier for sevoflurane and that the data of Lu et al. must be interpreted with caution.
-
The majority of patients with Duchenne's muscular dystrophy require corrective spinal surgery for scoliosis to maintain seated balance and to slow the progression of respiratory compromise, thereby facilitating nursing and enhancing their quality of life. Traditionally patients with a pre-operative forced vital capacity (PFVC) of 30% or below predicted have been denied this surgery as it was thought that the incidence of postoperative complications was unacceptably high. ⋯ These cases indicate that there is no clinically significant difference in operative and postoperative outcomes between patients with PFVC > 30% and < or =30%. However, the routine postoperative use of mask ventilation to facilitate early tracheal extubation is vital.
-
A 45-year-old alcoholic man presented following several short grand-mal seizures. He was not known to be epileptic. ⋯ The patient recovered within 4 h of management with oxygen, fluids and sodium bicarbonate. Lactic acidosis following convulsions is often associated with spontaneous resolution and a favourable outcome.
-
Of the forms of muscular dystrophy, myotonic dystrophy has the greatest systemic involvement. Although most patients with myotonic dystrophy show normal sensitivity to non-depolarising neuromuscular blocking drugs, some have been reported to show greatly increased sensitivity to these drugs, and little is known about the sensitivity of different muscles. ⋯ The calculated ED50 for the orbicularis oculi (7.77 microg x kg(-1) (95% CI 3.10-16.8 microg x kg(-1))) was lower than for the adductor pollicis (25.3 microg x kg(-1) (95% CI 20.7-43.3 microg x kg(-1))) and flexor hallucis brevis muscles (29.5 microg x kg(-1) (95% CI 11.0-85.6 microg x kg(-1); p < 0.01)). The ED90 was also lower for the orbicularis oculi (35.7 microg x kg(-1) (95% CI 14.8-66.5 microg x kg(-1))) than for the other muscles (51.8 microg x kg(-1) (95% CI 29.3-145.0 microg x kg(-1)) and 50.6 microg x kg(-1) (95% CI 5.29-642.0 microg x kg(-1)), respectively) (p < 0.01)).