Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2015
Randomized Controlled TrialA pilot study on the effect of nasal continuous positive airway pressure on arterial partial pressure of carbon dioxide during spinal anesthesia with intravenous sedation for total knee arthroplasty.
Deep sedation of surgical patients may be associated with hypoventilation, airway collapse, and hypercarbia, although the extent of hypercarbia is rarely quantified. In this prospective, randomized, controlled clinical pilot study, we assessed the efficacy of nasal continuous positive airway pressure (nCPAP) for reducing arterial partial pressure of carbon dioxide (PaCO2) among deeply sedated, spontaneously ventilated patients undergoing total knee arthroplasty (TKA) under subarachnoid block (SAB), versus standard airway management in a control group. ⋯ Deep sedation of TKA patients during SAB resulted in moderate hypercarbia (mean and median PaCO2 = 55). There was a trend showing that nCPAP treatment reduced PaCO2 versus treatment for control group patients receiving standard airway management; however, estimated treatment difference varied widely, from 1.4 to 12.6 mm Hg. Among control group patients, the initial PaCO2 during deep sedation was similar to the PaCO2 when measured after a 30-minute period of continued deep sedation. Finally, baseline PaCO2 among deeply sedated patients who received an airway was not different from that of patients who did not receive an airway.
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Anesthesia and analgesia · Feb 2015
Randomized Controlled Trial Comparative StudyExcess Costs and Length of Hospital Stay Attributable to Perioperative Respiratory Events in Children.
This prospective matched-cohort study from Thailand found that children experiencing a perioperative respiratory event were subsequently hospitalized twice as long, incurred 30% higher hospital costs, along with 58% higher indirect costs.
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Anesthesia and analgesia · Feb 2015
Randomized Controlled Trial Comparative StudyThe Effectiveness of Oxygen Delivery and Reliability of Carbon Dioxide Waveforms: A Crossover Comparison of 4 Nasal Cannulae.
Effective O2 delivery and accurate end-tidal CO2 (ETCO2) sampling are essential features of nasal cannulae (NCs) in patients with compromised respiratory status. We studied 4 NC designs: bifurcated nasal prongs (NPs) with O2 delivery and CO2 sensing in both NPs (Hudson), separate O2/CO2 NPs (Salter), and CO2 sensing in NPs with cloud O2 delivery outside the NPs via multi vents (Oridion) and dual vents (Medline). We hypothesized that design differences between NCs would influence O2 delivery and ETCO2 detection. ⋯ NCs provide supplemental inspired O2 concentrations for patients with impaired pulmonary function. Accurate measures of ETCO2 are helpful in assessing respiratory rate and determining whether CO2 retention is occurring from hypoventilation. These findings suggest the NC with separate NPs was the most effective in delivering O2 and the most consistent at providing reliable CO2 waveforms at higher FGFs.
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Anesthesia and analgesia · Feb 2015
The Incidence and Risk Factors for Perioperative Cardiac Arrest Observed in the National Anesthesia Clinical Outcomes Registry.
Cardiac arrest is a rare but important event in the operating room and postanesthesia care unit, when surgical patients are most intensively monitored. Several recent publications have reported the rate of cardiac arrest in surgical patients during the subsequent hospital stay but have not uniquely identified the immediate perioperative period. We hypothesized that cardiac arrest during this time (intraprocedure and postanesthesia care) would occur at a lower frequency than that described for inpatient hospital care in the available literature. ⋯ The National Anesthesia Clinical Outcomes Registry is an emerging resource for examination of perioperative and anesthesia-related outcomes. Cardiac arrest is less frequent in the periprocedural setting than later in the hospital course, with most arrests predictably occurring in patients with ASA physical status III-V. The finding of increased risk of mortality in male patients cannot be readily explained and should prompt future research attention.
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Anesthesia and analgesia · Feb 2015
Irritant Volatile Anesthetics Induce Neurogenic Inflammation Through TRPA1 and TRPV1 Channels in the Isolated Mouse Trachea.
Irritating effects of volatile general anesthetics on tracheal nerve endings and resulting spastic reflexes in the airways are not completely understood with respect to molecular mechanisms. Neuropeptide release and neurogenic inflammation play an established role. ⋯ Our results confirm the clinical experience that desflurane is more irritating than isoflurane at equal anesthetic gas concentration, whereas sevoflurane does not activate tracheobronchial sensory nerves to release neuropeptides and induce neurogenic inflammation. Both irritant receptor channels, TRPA1 more than TRPV1, are involved in mediating the adverse effects that may even extend to systemic proinflammatory sequelae.