Issues

Intraoperative hypotension may be an important factor in the development of postoperative complications. Data from 27,381 patients undergoing 33,330 noncardiac surgeries were studied to determine the durations of various mean arterial pressures (MAP) that were associated with acute kidney injury and myocardial injury. Acute kidney injury occurred after 7.4% of surgeries while myocardial injury occurred after 2.3% of surgeries and 1.5% of patients died within 30 days of surgery. Any time spent with a MAP of less than 55 mmHg during noncardiac surgery was independently associated with an increased risk of acute kidney injury and myocardial injury. As the time with a MAP of less than 55 mmHg increased so too did the risk for acute kidney injury and myocardial injury. Thirty-day mortality was associated with more than 20 min of MAP less than 55 mmHg. Optimizing intraoperative hemodynamics may improve patient outcomes.

The authors developed an intraoperative predictive model for unplanned postoperative intensive care unit admission (area under the curve of the receiver operating characteristic curve 0.905, 95% CI, 0.900–0.909) and internally validated this model. This model may improve the process of allocating intensive care unit beds postoperatively.

Using patient data from the Massachusetts General Hospital, the Risk Stratification Indices had excellent discrimination and poor calibration but the 30-day mortality Risk Quantification Index performed well.

In women at cesarean delivery, oxytocin, 5 U and carbetocin 100 μg, produced a similar 25% reduction in mean arterial pressure lasting less than 2 min. Cardiac stroke volume was not increased in women receiving placebo, despite good uterine tone, questioning the autotransfusion hypothesis.

In myometrial strips obtained at elective cesarean delivery from women not receiving oxytocin, in vitro pretreatment to oxytocin at concentrations more than 10⁻¹⁰ M reduced the subsequent contractile response to oxytocin. These data suggest that oxytocin-induced desensitization might explain the greater oxytocin dose required and greater bleeding in women at cesarean delivery who have undergone oxytocin-augmented labor.

Phasic, but not tonic, inspiratory activity of the genioglossus and palatoglossus muscles increases progressively with decreasing depth of sevoflurane anesthesia in spontaneously breathing children.

In a randomized, cross-over, multiple blinded study of healthy adult volunteers using 30 ml/kg over 1 h of either 0.9% saline or Plasmalyte, the authors found that measures of cognition did not differ, despite expected differences in plasma chemistry.

The investigators propose a new scoring system that includes performance tolerance such that more than 80% of subjects are considered recovered in the cognitive domain at 3 days. There were no important differences between methods of delivery; telephone administration of PQRS is thus, valid.

Both sevoflurane and propofol based anesthesia increased electrocorticographic spike frequency and amplitude in a dose-dependent manner at comparable bispectral index ranges. Rather than interfering with detection, deeper levels of general anesthesia might actually facilitate intraoperative elctrocorticographic detection of epileptiform foci.

Exposure of human renal cancer cells to isoflurane (0.5–2%, 2 h) resulted in up-regulation of levels of hypoxia-inducible factor-1α and -2α along with enhanced cell migration and cytoskeleton rearrangements. Isoflurane promotes cancer cell growth and migration in vitro and hence enhances malignant potential.

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Sevoflurane protected ventricular myocytes against H₂O₂-induced cellular Ca²⁺ overload and hypercontracture by correcting electrophysiological abnormalities associated with cellular Ca²⁺ handling.

In mice, miR-21 contributes to the renoprotective effect (attenuation of tubular damage, apoptosis, and lipid peroxidation) of Xenon in vivo by inhibiting apoptosis and the Akt signaling pathway.

Full closed-loop controlled ventilation, in comparison with pressure support ventilation, improved oxygenation, ventilatory variability and time spent in an adequate ventilation zone in critically ill patients.

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A unilateral loss of aeration can lead to ventilator-induced lung injury in the contralateral uninjured lung.

Twelve hours of mechanical ventilation, both negative pressure and positive pressure, resulted in similar levels of ventilator-induced diaphragmatic dysfunction, and the levels of lung injury did not affect the magnitude of diaphragmatic dysfunction.

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During the first half hour after bolus injection of 3.5 μg/kg fentanyl, the probability of respiratory depression exceeds that of analgesia. The shape of the utility function depends on the response thresholds chosen and the rate of drug administration.

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In a prospective, blinded, placebo-controlled trial conducted on a heterogeneous group of chronic pain patients, no analgesic effects were identified during 22 days of intrathecal gabapentin infusion.

Nuclear factor κB, a nuclear transcription factor that is increased under hyperglycemic conditions, contributes to pain-related hypersensitivity in ischemic pain.