Anesthesiology
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Randomized Controlled Trial
Identifying and Treating Opioid Side Effects: The Development of Methylnaltrexone.
Methylnaltrexone Reverses Chronic Opioid-induced Constipation: A Randomized, Controlled Trial. By Yuan CS, Foss JF, O'Connor M, Osinski J, Karrison T, Moss J, Roizen MF. JAMA 2000; 130:142-8. Reprinted with permission.
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Randomized Controlled Trial
Triple-low Alerts Do Not Reduce Mortality: A Real-time Randomized Trial.
Triple-low events (mean arterial pressure less than 75 mmHg, Bispectral Index less than 45, and minimum alveolar fraction less than 0.8) are associated with mortality but may not be causal. This study tested the hypothesis that providing triple-low alerts to clinicians reduces 90-day mortality. ⋯ Real-time alerts to triple-low events did not lead to a reduction in 90-day mortality, and there were fewer responses to alerts than expected. However, similar mortality with and without responses suggests that there is no strong relationship between responses to triple-low events and mortality.
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Comparative Study
Total Intravenous Anesthesia versus Inhalation Anesthesia for Breast Cancer Surgery: A Retrospective Cohort Study.
Cutting to the chase...
This large, retrospective study with propensity-matched controls found NO difference in breast cancer survival between inhalataional and intravenous anesthetic techniques.
Why is this still important?
Following Exadaktylos' eye-popping 2006 retrospective, along with a few in vitro studies, anesthetists have been a little anxious that anesthetic technique choice could potentially have a such significant effect on cancer recurrence. To date, other trials have not replicated Exadaktylos' original results.
What was studied this time?
Yoo et al performed a retrospective study of 5,331 breast cancer patients over a 8 year period, looking at the relationship between anesthetic technique and both 5-year recurrence-free and overall survival.
There was no difference for either survival metric between inhalational or intravenous anesthesia.
So does this settle it?
Not yet. Although large and high quality, this is still a retrospective study with all the compromises that this brings.
Be smart
While we await results from prospective, randomized trials, we should not be distracted by the magical promise of one technique over another, and instead address the very real impact that anesthesia can have on patient Return to Intended Oncological Therapy (RIOT).
summary -
Positive end-expiratory pressure is usually considered protective against ventilation-induced lung injury by reducing atelectrauma and improving lung homogeneity. However, positive end-expiratory pressure, together with tidal volume, gas flow, and respiratory rate, contributes to the mechanical power required to ventilate the lung. This study aimed at investigating the effects of increasing mechanical power by selectively modifying its positive end-expiratory pressure component. ⋯ Less than 7 cm H2O positive end-expiratory pressure reduced atelectrauma encountered at zero end-expiratory pressure. Above a defined power threshold, sustained positive end-expiratory pressure contributed to potentially lethal lung damage and hemodynamic impairment.