Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2011
Comparative Study Clinical TrialTransient hemodynamic change and accuracy of arterial blood pressure-based cardiac output.
The purpose of this study was to determine the effects of transient arterial blood pressure change on the accuracy of the FloTrac™/Vigileo™ monitor (Edwards Lifesciences, Irvine, CA). ⋯ The FloTrac/Vigileo measured stroke volume with reasonable accuracy during transient hypotension but overestimated stroke volume during transient hypertension.
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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
Biography Historical ArticleRoss C. Terrell, PhD, an anesthetic pioneer.
On December 30, 2010, Ross C. Terrell, PhD, died. With his passing at age 85, we lost one of the pioneers of modern anesthesia. Terrell synthesized most of the inhalation anesthetics used today, including desflurane, enflurane, isoflurane, and sevoflurane.
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Anesthesia and analgesia · Aug 2011
Performance characteristics and validation of the Opioid-Related Symptom Distress Scale for evaluation of analgesic side effects after orthopedic surgery.
The Opioid-Related Symptom Distress Scale (ORSDS) is a 4-point scale that evaluates 3 symptom distress dimensions (frequency, severity, bothersomeness) for 12 symptoms. The symptom-specific ORSDS is the average of the 3 symptom distress dimensions. The composite ORSDS is the average of 12 symptom-specific scores. The ORSDS was validated for outpatient laparoscopic cholecystectomy (under general anesthesia) by assessment of internal consistency, content validity, construct validity, principal components analysis, known group validity, responsiveness, and opioid dose dependency. Additional validation studies were suggested. We investigated performance characteristics and validity of the ORSDS for postoperative analgesia after 4 types of anesthetic and analgesic regimens. ⋯ Validity of the ORSDS was supported by predetermined validation criteria, including measures of internal consistency, content validity, construct validity, principal components analysis, known group validity, responsiveness, and correlation with opioid intake. The ORSDS is a valid tool for assessment of opioid side effects after orthopedic surgery, and can be used in clinical trials involving a wide variety of anesthetic and analgesic regimens.