Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Clinical TrialEmergence of elderly patients from prolonged desflurane, isoflurane, or propofol anesthesia.
Recovery from prolonged anesthesia might be compromised in elderly patients. Desflurane (DES) may be particularly well suited to achieve a rapid postoperative recovery because of its low lipid solubility. Postoperative recovery was compared in 45 elderly patients randomized to receive either DES, isoflurane (ISO), or propofol (PRO) to maintain anesthesia. Anesthesia was induced with PRO, vecuronium, and fentanyl and maintained with N2O, fentanyl, and the study drug. Times from end of anesthesia to tracheal extubation, eye opening and hand squeezing on command, and ability to state name and date of birth were recorded. Sedation and psychometric evaluation were tested 0.5, 1, 1.5, 2, and 24 h postoperatively. Results are given as means +/- SD. Differences among were analyzed by chi2 or analysis of variance. P < 0.05 compared with DES was considered significant. After a prolonged anesthesia (199 +/- 57 min with DES), immediate recovery times were significantly shorter with DES than with ISO or PRO (times to eye opening: 5.6 +/- 3.4 min, 11.5 +/- 8.4 min, and 11.9 +/- 7.6 min; times to extubation: 6.9 +/- 3 min, 13.1 +/- 8.9 min, 9.9 +/- 6.5 min for DES, ISO, and PRO, respectively). Intermediate recovery, as measured by psychometric testing, sedation levels, and time to discharge from the postanesthesia care unit, was similar in the three groups. In this study, DES provided a transient advantage compared with ISO or PRO with respect to early recovery after prolonged general anesthesia in elderly patients. ⋯ Recovery from prolonged anesthesia can sometimes be problematic in elderly patients. We evaluated 45 elderly patients who received either desflurane, isoflurane, or propofol for anesthesia. We found that desflurane provided a transient advantage in terms of postoperative recovery, but whether this difference is clinically important remains to be demonstrated.
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Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Comparative Study Clinical TrialEffects of oxygenation during selective lobar versus total lung collapse with or without continuous positive airway pressure.
Hypoxemia is common during anesthesia with one-lung ventilation (OLV). This study tested the hypothesis that selective lobar blockade would result in higher PaO2 values compared with those found with total lung collapse independent of continuous positive airway pressure (CPAP) application. Thirty patients undergoing lobectomy were randomly assigned to one of four groups with the following maneuvers during OLV: Group 1 (n = 8) total lung collapse (TLC) plus 5 cm H2O of CPAP to the nonventilated operative lung for 15 mins, followed by selective lobe collapse plus 5 cm H2O of CPAP (during selective collapse only the surgical lobe was collapsed and the rest of that lung was ventilated); Group 2 (n = 6) selective lobar collapse plus 5 cm H2O of CPAP to the operative lung, followed by TLC plus 5 cm H2O of CPAP; Group 3 (n = 8) total lung collapse without CPAP, followed by selective lobe collapse and no CPAP; Group 4 (n = 8) selective lobe collapse without CPAP, followed by TLC and no CPAP. To obtain selective lobe collapse, the bronchial blocker of the Univent (Vitaid, Lewiston, NY) endotracheal tube was guided into the operative bronchus with the aid of a fiberoptic bronchoscope. Blood pressure, heart rate, and arterial blood gas measurements were obtained during the following times: Time 1--while the patient was awake; Time 2--two-lung ventilation (2LV) in the supine position; Time 3--after 30 min of OLV in the lateral decubitus position (no CPAP or selective blockade); Time 4 and Time 5--during maneuvers described above (see group description); Time 6--2LV resumed; Time 7--30 min after extubation. Twenty-eight patients completed the study. There were no differences among groups with regard to arterial blood pressure, heart rate, or arterial oxygen saturation during the experimental maneuvers. All four groups showed a decrease in PaO2 from 2LV to OLV (P < 0.05). Both with and without CPAP application, oxygenation was improved with selective lobe collapse compared with TLC. When selective lobe collapse with 5 cm H2O of CPAP followed TLC (group 1), PaO2 values increased to values similar to those found for 2LV (PaO2 449 +/- 122 vs 394 +/- 105 mm Hg). This study indicates that by using a bronchial blocker, changing from total lung collapse to selective lobar blockade improves PaO2 during lung surgery. ⋯ This study examines how oxygen tension in arterial blood can be higher during one-lung ventilation. The use of a bronchial blocker, which changes a total lung collapse to selective lobar blockade, improves oxygenation during lung surgery.
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Anesthesia and analgesia · Sep 1997
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of light wand and suspension laryngoscopic intubation techniques in outpatients.
Endotracheal intubation can produce postoperative sore throat and hoarseness, as well as changes in cardiovascular variables. A major goal of ambulatory surgery is the prompt return of patients to their daily activities. Postoperative sore throat may impede this and may decrease patient satisfaction with their anesthetic and surgical experience. We conducted a prospective, randomized study in 40 outpatients having lower extremity arthroscopies to compare the effects of direct laryngoscopy and light wand intubation on cardiovascular changes, sore throat, hoarseness, and dysphagia. Subjects were randomly assigned to either Group A (endotracheal intubation by rigid laryngoscopy) or Group B (endotracheal intubation with a light wand). A standardized anesthetic technique was used. Heart rate and blood pressure were recorded before induction, after induction but before endotracheal intubation, and at 1-min intervals for the first 5 min after intubation. Sixteen to twenty-four hours postoperatively, the incidence and severity of sore throat, hoarseness, and dysphagia was assessed by a follow-up phone call. This study demonstrated no clinically significant difference in cardiovascular variables between the two techniques. Patients had a significantly lower incidence and severity of sore throat, hoarseness, and dysphagia when a light wand was used for intubation. In conclusion, this study suggests that light wand intubation may decrease the incidence and severity of postoperative sore throat, hoarseness, and dysphagia, thereby potentially increasing satisfaction in ambulatory surgical patients. ⋯ This prospective, randomized study found that the incidence and severity of postoperative sore throat, hoarseness, and difficulty in swallowing among ambulatory surgical patients is more frequent when they are endotracheally intubated with a rigid laryngoscope than with a light wand. The authors, therefore, recommend more frequent use of the light wand for endotracheal intubation.
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Anesthesia and analgesia · Sep 1997
Comparative StudyDose-response and time course of effect of rocuronium in male and female anesthetized patients.
To determine differences from dose-response and time-course of rocuronium between male and female patients, 60 adult patients (30 male and 30 female), ASA grade I, aged 17-52 yr, undergoing elective plastic surgery were studied. Anesthesia was maintained with 60% nitrous oxide in oxygen, thiopental, and incremental doses of fentanyl as required. Neuromuscular function was assessed mechanomyographically with train-of-four (TOF) stimulation at the wrist every 12 s, and the percentage depression of the T1 response was used as the study variable. The dose-response relationship of rocuronium was determined by a cumulative dose-response technique. The results showed that the dose-response curve of rocuronium in the men was shifted to the right, indicating a decrease in the sensitivity to rocuronium-induced neuromuscular block versus the women. The 50%, 90%, and 95% effective doses of rocuronium were 178.4 +/- 53.7, 358.7 +/- 101.3, and 386.2 +/- 113.4 microg/kg, respectively, in male patients, and 128.8 +/- 42.5, 252.8 +/- 51.7, and 274.4 +/- 59.4 microg/kg in female patients. After an intravenous administration of total dose of 400 microg/kg rocuronium, neuromuscular block was significantly longer in the men than in the women. The duration of peak effect, clinical duration, and total duration were 6.5 +/- 3.0, 12.5 +/- 4.9, and 33.6 +/- 8.7 min, respectively, in male patients, and 11.8 +/- 2.7, 18.5 +/- 5.3, and 46.8 +/- 9.6 min in female patients. We conclude that women were approximately 30% more sensitive to rocuronium compared with men. ⋯ The authors found that women were 30% more sensitive to rocuronium than men. This suggests that the routine dose of rocuronium should be reduced in women compared with men.
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Anesthesia and analgesia · Sep 1997
Comparative StudyThe effect of priming with vecuronium and rocuronium on young and elderly patients.
The priming principle consists of administering a subparalyzing dose of nondepolarizing neuromuscular blocking drug 3-6 min before giving a second dose for tracheal intubation. This study was performed to observe the effects of priming doses of vecuronium and rocuronium on pulmonary function tests and muscular weaknesses in young (25-35 yr of age) and elderly (65-73 yr of age) patients. Ten young and 10 elderly patients were each placed in vecuronium and rocuronium groups. Oxygen saturation and train-of-four (TOF) ratio were determined, and pulmonary function tests were performed. Then 20% of the 95% effective dose (ED95) of the muscle relaxants was given intravenously. All tests were performed again 4 min after vecuronium and 3 min after rocuronium. Other signs of muscular weaknesses were also recorded. Elderly patients showed more signs of muscle weakness in both groups. The TOF ratio was 0.77 and 0.79 in the elderly rocuronium and vecuronium groups, respectively, and 0.89 and 0.90 in the young rocuronium and vecuronium groups, respectively. Dynamic spirometry revealed decreases in forced expiratory volume in 1 s and forced vital capacity in both groups, and no significant changes in peak expiratory flow rate. The expiratory reserve volume was reduced more in the elderly groups. Oxygen saturation decreased in both groups. We conclude that oxygen saturation, pulmonary function, and muscle strength decrease more in the elderly than in their younger counterparts from priming doses of vecuronium or rocuronium. ⋯ The priming principle consists of giving a subparalyzing dose of muscle relaxant 3-6 min before giving a second dose for tracheal intubation. We found that priming doses of vecuronium and rocuronium produced greater decreases in oxygen saturation and pulmonary function in the elderly (aged 65-73 yr) than their younger (aged 25-35 yr) counterparts. Priming may not be a safe approach in elderly patients.