Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2011
Randomized Controlled Trial Comparative StudyIntravenous sodium bicarbonate verifies intravenous position of catheters in ventilated patients.
Extravasation is the unintentional injection or leakage of fluids into the perivascular or subcutaneous space resulting in potential tissue injury. In this 2-part prospective, controlled study, we assessed the safety of subcutaneously injected sodium bicarbonate in rats first. In the second part, the diagnostic utility of using IV diluted sodium bicarbonate to confirm placement of IV catheters in endotracheally intubated and ventilated rats and patients was tested. Diluted sodium bicarbonate was created using undiluted standard 8.4% (1 mEq/mL) sodium bicarbonate mixed in a 1:1 ratio with sterile water to achieve a final diluted concentration of 4.2% (0.5 mEq/mL). ⋯ The injection of diluted sodium bicarbonate (in mechanically ventilated patients) can be used to reliably identify the correct location of an IV catheter by an increase in the exhaled carbon dioxide concentration. Although we found no skin damage with 4.2% (0.5 mEq/mL) sodium bicarbonate, safety and efficacy should be further evaluated in future studies.
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Anesthesia and analgesia · Aug 2011
ReviewThe physiologic implications of isolated alpha(1) adrenergic stimulation.
Phenylephrine and methoxamine are direct-acting, predominantly α(1) adrenergic receptor (AR) agonists. To better understand their physiologic effects, we screened 463 articles on the basis of PubMed searches of "methoxamine" and "phenylephrine" (limited to human, randomized studies published in English), as well as citations found therein. Relevant articles, as well as those discovered in the peer-review process, were incorporated into this review. ⋯ Furthermore, the cost of increased blood pressure after pure α(1)-agonism is almost invariably decreased cardiac output, likely due to increases in venous resistance. The venous system contains α(1) ARs, and though stimulation of α(1) ARs decreases capacitance and may transiently increase venous return, this gain may be offset by changes in afterload, venous compliance, and venous resistance. Data on the effects of α(1) stimulation in the central nervous system show conflicting changes, while experimental animal data suggest that renal blood flow is reduced by α(1)-agonists, and both animal and human data suggest that gastrointestinal perfusion may be reduced by α(1) tone.
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Anesthesia and analgesia · Aug 2011
Automatic notifications mediated by anesthesia information management systems reduce the frequency of prolonged gaps in blood pressure documentation.
Arterial blood pressure (BP) measurement at least every 5 minutes is part of the American Society of Anesthesiologists' monitoring standard, but prolonged BP gaps in electronic anesthesia records have been noted. We undertook multicenter studies to determine the frequency of cases with at least 1 interval ≥10 minutes between successive BP measurements and then to ascertain whether educational feedback via an electronic, near real-time notification system alerting providers to the presence of such gaps would reduce their incidence. ⋯ BP gaps of ≥10 minutes were common in electronic anesthesia records, and their incidence was reduced but not eliminated by near real-time feedback to providers. The American Society of Anesthesiologists' standard for BP documentation every 5 minutes might not be achievable with current practices and technology. Anesthesia information management systems users need to be cognizant of the potential for gaps in BP measurement, take steps to minimize their occurrence, and document an explanation when such failures occur.
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Anesthesia and analgesia · Aug 2011
Clinical TrialFactors affecting the decision to defer endotracheal extubation after surgery for congenital heart disease: a prospective observational study.
Fast-tracking and early endotracheal extubation have been described in patients undergoing surgery for congenital heart disease (CHD); however, criteria for patient selection have not been validated in a prospective manner. Our goal in this study was to prospectively identify factors associated with the decision to defer endotracheal extubation in the operating room (OR). ⋯ Preoperatively known factors alone can predict the relative chances of deferring extubation after surgery for CHD. The early extubation strategies applied in the 2 centers were successful in the majority of cases.