Training resident anesthesiologists in adult challenging intubation comparing Truview EVO2 and Macintosh laryngoscope: a preliminary study.

AIM: Teaching airway management continues to be of high importance to the anesthesiologist, since the care of each individual patient depends on the expertise, training and knowledge of the anesthetist with different airway devices, techniques and algorithms. The aim of our study was to compare intubation performed by resident anesthesiologists in training, under senior supervision, using Truview EVO2 (Group 1) or Macintosh blade (Group 2) in a group of adult patients undergoing elective surgery. METHODS: This was a pilot prospective study. Thirty patients who were scheduled for surgery under general anesthesia were randomized into two groups. In Group 1, intubation was performed by using the Truview EVO2, and in Group 2 intubation was performed by using the Macintosh blade. Mallampati score, thyromental distance and neck mobility were recorded for each patient. The exclusion criteria included a Mallampati score =or<2 and a Patil distance >6 cm. The time of intubation and any occurrence of complications were recorded. RESULTS: Intubation was always successful on the first attempt in Group 1, while it failed for 46.7% of patients in Group 2 (P=0.006). The time of intubation was not different between the two groups. No complications were recorded for Group 1 (Truview), while seven were reported in Group 2 (Macintosh) (P=0.003). CONCLUSIONS: The resident managed to intubate all patients on the first attempt with the Truview, which led to a lower incidence of complications. Despite the exiguity of the population in the study, Truview EVO2 and other videolaryngoscopes can be considered to be useful tools in training resident anesthesiologists in elective intubation.

[Labetalol in the prophylaxis of postoperative arterial hypertension in surgery of the posterior cranial fossa]. / Il labetalolo come profilassi della ipertensione arteriosa post-operatoria nella chirurgia della fossa cranica posteriore.

Increased catecholamines are one of the factors responsible for post-operative arterial hypertension. In order to prevent this severe complication labetalol, an alpha and beta blocking drug, was infused following the closure of the dura mater in half of the patients studied. For two hours after surgery blood pressure values in treated patients were constantly lower than those recorded in the control group, thus confirming the efficacy of this drug in preventing the cardiocirculatory effects of increased adrenalin and noradrenalin.

Construction of a functional lactose permease devoid of cysteine residues.

By use of oligonucleotide-directed, site-specific mutagenesis, a lactose (lac) permease molecule was constructed in which all eight cysteinyl residues were simultaneously mutagenized (C-less permease). Cys154 was replaced with valine, and Cys117, -148, -176, -234, -333, -353, and -355 were replaced with serine. Remarkably, C-less permease catalyzes lactose accumulation in the presence of a transmembrane proton electrochemical gradient (interior negative and alkaline). Thus, in intact cells and right-side-out membrane vesicles containing comparable amounts of wild-type and Cys-less permease, the mutant protein catalyzes lactose transport at a maximum velocity and to a steady-state level of accumulation of about 35% and 55%, respectively, of wild-type with a similar apparent Km (ca. 0.3 mM). As anticipated, moreover, active lactose transport via C-less permease is completely resistant to inactivation by N-ethylmaleimide. Finally, C-less permease also catalyzes efflux and equilibrium exchange at about 35% of wild-type activity. The results provide definitive evidence that sulfhydryl groups do not play an essential role in the mechanism of lactose/H+ symport. Potential applications of the C-less mutant to studies of static and dynamic aspects of permease structure/function are discussed.

Sequential truncation of the lactose permease over a three-amino acid sequence near the carboxyl terminus leads to progressive loss of activity and stability.

Previous experiments are consistent with the notion that residues 396-401 (... SVFTLS ...) at the carboxyl terminus of the last putative transmembrane helix of the lactose (lac) permease of Escherichia coli are important for protection against proteolytic degradation and suggest that this region of the permease may be necessary for proper folding. Stop codons (TAA) have now been substituted sequentially for amino acid codons 396-401 in the lacY gene, and the termination mutants were expressed from the plasmid pT7-5. With respect to transport, permease truncated at residue 396 or 397 is completely defective, while molecules truncated at residues 398, 399, 400, and 401, respectively, exhibit 15-25%, 30-40%, 40-45%, and 70-100% of wild-type activity. As judged by pulse-chase experiments with [35S]methionine, wild-type permease or permease truncated at residue 401 is stable, while permease molecules truncated at position 400, 399, 398, 397, or 396 are degraded at increasingly rapid rates. The findings indicate that either the last turn of putative helix XII or the region immediately distal to helix XII is important for proper folding and protection against proteolytic degradation.