This Month in Anesthesiology

Abstract

For smoked cannabis, lower doses produced a window of modest analgesia and higher doses increased pain.Wall motion abnormalities after CABG surgery are associated with increased risk of long-term adverse cardiac morbidity.Premotor electroencephalographic potentials could be markers of patient–ventilator asynchrony.During a 1-yr period, 60 neonates and infants scheduled for congenital heart disease repair had central venous catheterization performed using either the ultrasound-guided skin-marking method (n = 27) or the real-time ultrasound-assisted method (n = 33). Results from this prospective, randomized study by Hosokawa et al . showed significantly better outcomes with the use of real-time ultrasound-assisted guidance. Using this method of guidance, anesthesiologists more quickly accomplished venous puncture, shortened time to catheterization, and required fewer needle passes to successfully place the catheters.Ungern-Sternberg et al . designed a prospective study to evaluate the safety of laryngeal mask airway (LMA) use in children with upper respiratory tract infection (URI) less than 2 weeks before anesthesia. The authors used parental questionnaires to classify the children’s URI histories. Incidence and timing of any adverse events were recorded for the perioperative period. The authors found that presence of a recent URI (seen in 27% of the 831 study participants) doubled the incidence of laryngospasm, cough, and oxygen desaturation when an LMA was used. This incidence rose in younger children, those undergoing ear, nose, and throat surgery, and those where multiple insertion attempts were made. All adverse respiratory events were easily managed. The authors conclude that 2 weeks is a suitable time period after a URI for elective surgery in children, and that LMA can be a viable alternative to endotracheal intubation in such cases.Previous studies have suggested that isoflurane and xenon interact at receptor proteins at very different sites. Using a grand canonical Monte Carlo simulation, Dickinson et al . were able to predict an overlapping binding site for xenon and isoflurane on N -methyl-d-aspartate (NMDA) receptors, which coincided with the glycine coagonist site. Further experiments showed that inhibition of NMDA receptors by xenon and isoflurane increases as glycine concentration decreases. For xenon, an additional component of noncompetitive inhibition at the binding site was observed. Of note to anesthesiologists is that neuroprotectants that act at the glycine site of the NMDA receptor antagonists are well tolerated in patients. See the accompanying Editorial View on page 694 This article summarizes the involvement of nitric oxide, endothelium-derived hyperpolarizing factor, or prostaglandin I2in anesthetic agents’ effects on regional and systemic circulation. In their comprehensive review, Toda et al . explore the beneficial–harmful duality of nitric oxide, elucidating its pivotal functions as endothelial messenger, neurotransmitter, and neuromodulator, as well as the detrimental effects to cell viability of excess nitric oxide. More human studies will be required to determine the validity of extrapolating findings from experimental animal studies to humans.This article has been selected for the Anesthesiology CME Program. See the accompanying Editorial View on page 689