Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1998
Jet ventilation in upper airway obstruction: description and model lung testing of a new jetting device.
Patients with critical upper airway stenosis require a tracheotomy for corrective surgery. We describe a new transtracheal device that permits safe ventilation of these patients without tracheotomy. It is based on a coaxial bicannular design that allows "push-pull" ventilation by jetting gas through the inner cannula and applying suction through the outer cannula. It further allows monitoring of airway pressure, tidal volume, and end-tidal CO2. The device was placed in the "trachea" of an artificial lung, and the preparation was made airtight by sealing the proximal end of the trachea. Tidal volumes and their associated pressures were measured simultaneously at different parts of the airway at several lung compliances and airway resistance settings while varying the jet and suction pressures. A large range of tidal volumes was achieved at safe airway pressures using clinically relevant airway resistance and lung compliance settings. Airway pressures measured through the device correlated well with pressures measured directly in the airways at the same time. Tidal volumes, measured through a Wright respirometer in the suction line, exceeded actual values at high suction settings and decreased below actual values at low suction settings. This new form of jet ventilation allowed efficient ventilation of the artificial lung with a totally occluded upper airway. ⋯ Tracheotomy is required for surgery to relieve stridor because gas forced into the trachea at high pressures through a percutaneously placed needle (jetting) cannot be exhaled quickly enough for respiration. We describe a device that allows jetting in the stridorous patient by actively assisting expiration, thereby eliminating the tracheotomy requirement.
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Anesthesia and analgesia · Oct 1998
Comment Letter Case ReportsRelief of chronic refractory hiccups with glossopharyngeal nerve block.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Multicenter Study Clinical TrialPostoperative analgesic effects of three demand-dose sizes of fentanyl administered by patient-controlled analgesia.
Many studies have demonstrated the postoperative analgesic efficacy of fentanyl delivered i.v. by patient-controlled analgesia (PCA) devices at demand doses ranging from 10 to 50 microg, but none has sought to define the optimal fentanyl PCA dose. In this randomized, double-blind, multicenter study, we compared the safety and efficacy of three administered demand-dose sizes of fentanyl (20, 40, and 60 microg) in 150 patients after major surgery. Efficacy was dose-dependent; positive response rates (i.e., a global assessment score of "very good" or "excellent" and the absence of severe opioid adverse effects) were 42%, 52%, and 68% for the 20, 40, and 60 microg demand-dose groups, respectively, and were significantly higher in the 60 microg demand-dose group. The number of doses administered and missed attempts were significantly smaller in the 40 and 60 microg demand-dose groups compared with the 20 microg demand-dose group. This suggests that the 20 microg demand dose provided inadequate pain relief. Adverse respiratory events were more frequent and mean respiratory rates were significantly slower with the 60 microg demand dose, compared with the 20 or 40 microg demand doses. These results indicate that, of these three doses, the 40 microg demand dose was optimal for fentanyl PCA management of moderate to severe pain after major surgery. ⋯ The postoperative analgesic efficacy of fentanyl delivered i.v. by patient-controlled analgesia devices has been demonstrated for demand doses ranging from 10 to 50 microg, but the optimal fentanyl dose remains unknown. In this randomized, double-blind study, we compared three demand dose sizes of fentanyl (20, 40, and 60 microg) and found that the 40 microg demand dose was the most appropriate for fentanyl patient-controlled analgesia management of postoperative pain.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Comparative Study Clinical TrialA granisetron-droperidol combination prevents postoperative vomiting in children.
This study was performed to compare the efficacy of a granisetron-droperidol combination with each antiemetic alone to prevent postoperative vomiting after tonsillectomy with or without adenoidectomy in children. One hundred eighty pediatric patients, ASA physical status I, aged 4-10 yr, were enrolled in a prospective, randomized, double-blind investigation and assigned to one of three treatment regimens: granisetron 40 microg/kg (Group G), droperidol 50 microg/kg (Group D), or granisetron 40 microg/kg plus droperidol 50 microg/kg (Group GD) (n = 60 in each group). These drugs were administered i.v. after an inhaled induction. The same standard general anesthetic technique and postoperative analgesia were used throughout. The rate of complete response, defined as no emesis and no need for rescue antiemetic, 0-3 h after anesthesia was 83% in Group G, 60% in Group D, and 97% in Group GD (P = 0.029 versus Group G, P = 0.001 versus Group D). The corresponding rates 3-24 h after anesthesia were 83%, 55%, and 97% (P = 0.029 versus Group G, P = 0.001 versus Group D). No clinically important adverse events were observed in any of the groups. In conclusion, a granisetron-droperidol combination is superior to each antiemetic alone in complete response in children undergoing general anesthesia for tonsillectomy. ⋯ We compared the efficacy of granisetron plus droperidol with each antiemetic alone for the prevention of postoperative vomiting in children. The granisetron-droperidol combination was highly effective against postoperative emesis.