This Month in Anesthesiology

Mechanisms underlying the alleged cancer-promoting effects of blood transfusion are unknown, including the involvement of donors' leukocytes, erythrocytes, and soluble factors. Two tumor models were used in rats to study the impact of blood transfusion on the host ability to clear circulating cancer cells and host survival rates. The potential deleterious characteristics of the transfusion were also studied. Blood transfusion, in conjunction with blood storage time, was found to be an independent and significant risk factor for cancer progression, and aged erythrocytes mediated the effects. In rats, transfusion of fresh blood is less harmful than transfusion of stored blood. These results have implications for cancer patients receiving erythrocyte transfusions. See the accompanying Editorial View on  page 951 

This study examined the effect of isoflurane on γ-aminobutyric acid (GABA) levels in pontine reticular formation and the effect of drugs that increase or decrease GABA levels in the pontine reticular formation in experimental animals. Compared with wakefulness, GABA levels were significantly decreased by isoflurane. Nipecotic acid increased GABA levels and increased isoflurane induction time, whereas 3-mercaptopropionic acid decreased GABA levels and decreased isoflurane induction time. These results indicate that decreasing rather than increasing pontine reticular formation GABA levels is one mechanism by which isoflurane causes loss of consciousness and altered cortical excitability. See the accompanying Editorial View on  page 948 

Using a new risk scale developed for children, the effect size was calculated for treatments recommended for the pediatric population in the new Guidelines for the Management of Postoperative Nausea and Vomiting. Six single-drug therapies and five combination treatments were analyzed for risk reduction. With single-agent therapy using the 5-hydroxytryptamine receptor antagonists or dexamethasone, a 50–60% relative risk reduction is expected. Droperidol offers only a 40% decrease. With the combinations of a 5-hydroxytryptamine receptor antagonist and dexamethasone, a relative risk reduction in vomiting of about 80% is expected.

In the senescent heart, β-adrenergic responsiveness is altered in parallel with β¹- and β²-adrenoceptor down-regulation. This study tested the hypothesis that the β³-adrenoceptor plays a role in β-adrenergic receptor dysfunction in the senescent heart. β-adrenergic responses were investigated in vivo  using echocardiography and in vitro  using isolated left ventricular papillary muscle in young adult and senescent rats. An impaired positive inotropic effect in parallel with β³-adrenoceptor up-regulation was confirmed in senescent hearts both in vivo  and in vitro . In the senescent group, the positive inotropic effect of β-adrenergic agonists was partially restored by nitric oxide synthase inhibitors. This was not the case in the young adult group. These results indicate β³-adrenoceptor overexpression plays a role in the altered β-adrenergic response in senescent cardiomyopathy via  the induction of nitric oxide. See the accompanying Editorial View on  page 956 

Supervision of anesthesia residents by an attending anesthesiologist is associated with a decreased incidence of complications during emergent intubations outside the operating room. See the accompanying Editorial View on  page 945 

Training for fiberoptic orotracheal intubation using a high-fidelity simulator was not different than training with a low-fidelity simulator.

Desmopressin is associated with a significant reduction in transfusion of blood products.

This review evaluates different methods for determination of sympathetic nervous system activity and describes its role in human neurohumoral circulatory control. The effects of general anesthesia on sympathetic nervous system activity and their relevance for clinical anesthesia are discussed.