Respiratory effects of fentanyl, diazepam, and methohexital sedation.

The respiratory depressant effects of fentanyl, diazepam, and methohexital were studied in 18 patients who were breathing room air. Two patients had 70% oxygen supplementation administered by a nasal inhaler. Varying degrees of hypoxia occurred when the narcotic was given but hypoxia was not seen in patients who received diazepam alone. The hypoxic changes may be attributed to various physiological responses and can probably be prevented with administration of adequate oxygen.     

Continuous transcutaneous oxygen tension monitoring during ultralight general anesthesia for oral surgery

The application of continuous, noninvasive, transcutaneous oxygen tension monitoring during ultralight general anesthesia is investigated. Transcutaneous PO₂ measurements showed a high correlation to simultaneously measured arterial PO₂. Significant hypoxia was observed in patients maintained on only room air during ultralight general anesthesia. In patients receiving supplemental oxygen by nasal mask, hyperoxic levels were noted throughout anesthesia, providing a significant margin of safety from hypoxia during periods of apnea or respiratory impairment.     

Evaluation by thoracic impedance cardiography of diazepam, placebo, and two drug combinations for intravenous sedation of dental outpatients

The cardiovascular and respiratory effects of three common intravenous premedicants were examined noninvasively in a population of 20 dental outpatients scheduled for surgical removal of third-molars. Two third molars from one side of the mouth were removed at each appointment. Group 1 received a diazepam titration (mean dose = 25.6 mgs) at one appointment and placebo at the other appointment. Group 2 received a combination of diazepam (12.5 mg), fentanyl (0.1 mg), and methohexital (mean dose = 18.0 mg) at one appointment and the combination of diazepam (15.0 mg) and methohexital (mean dose = 27.0 mg) at the other appointment. Noninvasive measurement of cardiac output revealed little change during intravenous drug administration, but a significant increase was seen in all groups following local anesthesia and during surgery. Heart rate was elevated and stroke volume decreased during administration of the two-drug combinations. Oxygen saturation was greatly decreased following the combination of diazepam, fentanyl, and methohexital. These findings indicate that the combination of diazepam, fentanyl, and methohexital results in decreased oxygen saturation, a transient decrease in stroke volume, and an elevated heart rate when used as an intravenous premedicant for dental outpatients.     

Simple orthodontic procedures can be safely performed on sick newborn babies

The heart rate and transcutaneous oxygen and carbon dioxide tensions were monitored while palatal impressions were taken and dental plates fitted in thirteen sick new born babies. Twenty-four such procedures were uneventful and only one procedure gave rise to transient hypoxia.     

Cardiorespiratory effects of a balanced anesthetic technique in outpatient general anesthesia.

Detailed measures have been made of the cardiorespiratory effects of a balanced general anesthetic technique on ten young patients undergoing oral surgery. The combination of fentanyl, diazepam, and atropine followed by N2O/O2 and methohexital resulted in a respiratory hyperoxic state throughout surgery and there was no evidence of hypercardia at any anesthesia stage. Cardiovascular stability was judged to be generally superior to that reported for techniques that have relied on methohexital without premedication. This balanced general anesthetic technique offers the oral surgeon-anesthetist a safe, effective, and practical alternative to techniques that rely on more potent anesthetic gases.     

Comparing efficacy and safety of four intravenous sedation regimens in dental outpatients.

BACKGROUND: Management of patients' fear and anxiety during dental treatment is a primary concern of dental practitioners. Pharmacological strategies used in outpatient dental settings must be both safe and effective. Regimens of intravenously administered sedative drugs were evaluated in a collaborative, multicenter study of outpatients undergoing removal of impacted third molars. METHODS: A total of 997 patients randomly received one of five treatments: placebo; midazolam administered to a clinical endpoint of conscious sedation (mean dose, 8.6 milligrams); midazolam plus additional midazolam as needed during the procedure (mean total dose, 12.2 mg); fentanyl (1.4 micrograms/kilogram) plus midazolam to achieve the same endpoint of conscious sedation (mean dose, 5.7 mg); or fentanyl (1.4 (micrograms/kg), midazolam (mean dose, 5.8 mg) and methohexital as needed during the procedure (mean dose, 61.0 mg). RESULTS: Each drug regimen reduced anxiety during surgery in comparison with placebo, with the combination of midazolam, fentanyl and methohexital resulting in significantly less anxiety in comparison with the other treatment groups. Pain reports by patients during surgery also were reduced significantly by the combination of fentanyl, midazolam and methohexital. Patients' global evaluations of the efficacy of sedation ranked midazolam with supplemental midazolam and the combination of fentanyl, midazolam and methohexital as significantly more efficacious than the other two drug regiments. The authors noted transient respiratory depression in patients in the two opioid-treated groups, but no other physiological changes were detected. CONCLUSIONS: These data provide evidence that the drugs and doses evaluated resulted in therapeutic benefit to dental outpatients, with minimal incidence of potentially serious adverse effects. CLINICAL IMPLICATIONS: The results of this large-scale study provide assurance to both the public and the dental profession of the safety of parenteral sedation with these drugs and combinations of these drugs when titrated slowly in the recommended doses by appropriately trained dentists.     

Incidence of hypoxemia in the postanesthetic recovery room in patients having undergone intravenous sedation for outpatient oral surgery

This study prospectively quantitated the incidence of hypoxia in outpatients in a postanesthetic recovery unit following intravenous (IV) sedation. After identifying the high incidence of hypoxia by the use of pulse oximetry, supplemental oxygen was given to another group of patients and the incidence of the hypoxia was again monitored. Twenty of 100 patients experienced hypoxic episodes in the postanesthetic recovery unit when no supplemental oxygen was administered; only 3 of an additional 100 patients who received supplemental oxygen had episodes of hypoxia. The difference between the groups receiving and not receiving supplemental oxygen was both clinically and statistically significant. As result of this study, the use of supplemental oxygen is recommended for all patients undergoing IV sedation for outpatient oral surgery.     

A double-blind comparison of low-dose intravenous ketamine and methohexital in adults

Two ultralight general anesthetic techniques, one using low-dose ketamine and the other using methohexital as the primary anesthetic agent, were compared for efficacy, safety, and psychomotor recovery in a double-blind fashion for use during third molar surgery. Low-dose intravenous ketamine as the primary anesthetic following premedication with fentanyl and midazolam, and in conjunction with nitrous oxide, appeared to produce less hypoxia, hypercarbia, and apnea than when methohexital was used. No significant differences were noted in heart rate or blood pressure between the techniques. The ketamine technique was universally preferred by the surgeons and anesthesiologists because of superior patient cooperation and airway management. No unpleasant psychomimetic side effects of significance were noted with the use of ketamine. Postoperative recovery took slightly longer in the ketamine group, with patients being judged fit for discharge approximately 10 to 15 minutes later than the patients who received methohexital.     

Prolonged recovery after intravenous diazepam

Prolonged recovery from intravenous diazepam after the day of administration has been examined in 2,468 consecutive patients who underwent oral surgery and general dentistry. Patients ranged in age from 2 to 94 years and received a mean diazepam dose of 19 mg, either by itself or with small amounts of methohexital sodium. Recovery was assessed by use of a questionnaire, and the answers were related to sexual gender, age, weight, dosage, procedure, duration, level of apprehension, and results of the sedation.     

Thrombophlebitis after intravenous use of anesthesia and sedation: its incidence and natural history.

A number of technical and clinical conditions reportedly associated with diazepam-related thrombophlebitis were investigated. Diazepam alone and in combination with fentanyl and methohexital was administered intravenously to 519 healthy, predominantly young adult patients undergoing routine oral surgery for removal of third molars. Indirect evidence is provided to show that two slightly different vasculopathies are involved: thrombophlebitis, in which pain and induration are both present but in which there is a slight delay in the time of inception of the condition; and phlebothrombosis, in which the reaction is almost immediate but pain is not significant and induration of the vein is the predominant feature. The overall incidence was 2.3% for thrombophlebitis and 9.8% for phlebothrombosis. There were four significant variables associated with phlebothrombosis: use of tobacco, use of oral contraceptives, multiple injections of diazepam, and pain during injection. The only significant variable associated with thrombophlebitis was the site of injection.     

Hemodynamics and oxygen saturation during intravenous sedation for office-based laser-assisted uvuloplasty.

PURPOSE: Patients undergoing office-based laser-assisted uvuloplasty (LAUP) for snoring or mild obstructive sleep apnea are generally obese and have a high Mallampati score. Because avoidance of supplemental oxygen during laser procedures is generally mandated, the potential for intraoperative desaturation is high. This study was designed to look at intraoperative hemodynamic changes, respiration patterns, and oxygen saturations during intravenous sedation with midazolam and fentanyl during LAUP procedures. MATERIALS AND METHODS: This was a retrospective anesthesia chart review of 15 consecutive patients undergoing midazolam/fentanyl intravenous sedation for office-based LAUP treatment for snoring and/or mild obstructive sleep apnea. Data recorded were noninvasive baseline and intraoperative hemodynamic measurements at 5-minute intervals for systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), pulse (P), and rate-pressure product (RPP). Data collected were reported as mean values with standard deviation. Statistical analysis using the Student's t test was performed and found significant for P<.05. RESULTS: All changes from baseline were statistically insignificant, SBP (P=.4), DBP (P=.2), MAP (P=.2), P (P=.1), PP (P=.9), RPP (P=.5), RR (P=.9), and SpO2 (P=.4), and all within +/-20% of baseline (range, -5.0% to +7.5%). CONCLUSION: Midazolam and fentanyl intravenous sedation with local anesthesia maintained intraoperative hemodynamic and oxygenation variables close to baseline for office-based LAUP procedures.     

Subanesthetic doses of ketamine,diazepam, and nitrous oxide for adult outpatient sedation

The use of ketamine in adults has been complicated by untoward hallucinatory emergence reactions. The addition of nitrous oxide and diazepam to subanesthetic doses of ketamine may be effective in decreasing these reactions. Adult patients were sedated for outpatient oral and maxillofacial surgery procedures using nitrous oxide, diazepam, and either fentanyl or ketamine. Postoperative questionnaires were used to evaluate hallucinatory reactions, amnesia, and patient acceptance. Comparison of the results of patients receiving ketamine and those receiving fentanyl revealed no statistical differences in hallucinatory reactions or patient acceptance. Amnesia was more complete in the ketamine than the fentanyl group.     

Moderate intravenous sedation for office-based full face laser resurfacing using a continuous infusion propofol pump.

PURPOSE: The purpose of this study was to compare the anesthetic requirements and hemodynamic and oxygenation variables involved between the bolus midazolam/fentanyl intravenous sedation-analgesia technique, and the same technique combined with continuous-infusion propofol. PATIENTS AND METHODS: This was a retrospective chart analysis of 41 consecutive patients undergoing full-face carbon dioxide laser resurfacing with either bolus midazolam/fentanyl (n = 15) or midazolam/fentanyl with continuous propofol infusion anesthesia (n = 26) techniques. Data recorded were noninvasive baseline and intraoperative hemodynamic measurements at 5-minute intervals for systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), pulse (P), and rate-pressure product (RPP), respiratory rate (RR), and oxygen saturation (SpO2). Data collected were reported as mean values with standard deviation. Statistical analyses were performed with the Student's t test and found statistically significant for P < .05. RESULTS: Statistically significant decreases in averages were seen in SBP (P < .001), DBP (P = .02), MAP (P = .004), P (P < .00l), RPP (P < .00l), and RR (P < .001), but not PP (P = .4) and SpO2 (P = .08) in the midazolam/fentanyl/continuous propofol infusion group compared with the midazolam/fentanyl only group. Changes from baseline were statistically significant only for MAP (P = .04), but statistically insignificant for all other measurements, SBP (P = .7), DBP (P = .4), P (P = .95), PP (P = .97), RPP (P = .6), RR (P = .6), and SpO2 (P = .4). Statistically significant smaller amounts of midazolam (P = .01) and fentanyl (P < .001) were used in the midazolam/fentanyl/continuous propofol infusion pump group. Length of procedure was statistically insignificant between groups (P = .4). Conclusion The addition of a continuous propofol pump maintained hemodynamic and oxygenation values close to baseline, while decreasing the amount of respiratory depressing opiates administered and without affecting the length of the procedure.     

Human cardiorespiratory and analgesic effects of intravenous diazepam and local anesthesia.

The only clinically detectable cardiovascular changes after intravenous diazepam administration are a moderate fall in systolic blood pressure and a rise in pulse rate. But it will produce significant cardiovascular changes, principally the lowering of total peripheral resistance and stroke volume. The drug has a long history of safety but is not totally innocuous. It is suggested that if diazepam is used in combination with methohexital, consideration should be given to the additive effects on total peripheral resistance.     

Staircase assessment of the magnitude and time-course of 50% nitrous-oxide analgesia.

The analgesic effect of 50% nitrous oxide and oxygen on thermal pain sensations was evaluated in a placebo-controlled, double-blind crossover design. In a session immediately before oral surgery, 20 patients used a seven-point verbal scale to rate the intensity of pain sensations evoked by three-second thermal stimuli delivered to 14 sites on the volar forearm at 20-second intervals by a 1-cm-diameter contact thermode. Subjects rated 36 stimuli while breathing room air and then two additional sets of 36 stimuli while inhaling 50% nitrous oxide and oxygen during one set and oxygen placebo during the other. Each of these two stimulus sets was preceded by a two-minute induction of the agent, and the sets were separated by a three-minute washout period. Order of administration was randomized and counterbalanced. Stimulus temperatures were adjusted continuously by an interactive computer program so that response could be maintained at predetermined levels. This method resulted in a continuous measure of analgesia in units of stimulus intensity. Results showed that, in comparison with placebo, nitrous oxide significantly increased the stimulus temperatures (mean = 0.42 degrees C) required to make the same response [F (11,209) = 6.76, p less than 0.0001], indicating analgesia. This increase was one-third to one-half that observed with clinical doses of intravenous fentanyl. Analgesic effects were apparent at three min and wanted 10 min after termination of nitrous-oxide inhalation. These times closely correlated with previous measures of alveolar concentration, further supporting the fast but modest analgesic action of nitrous oxide.     

A comparison of amnesia in outpatients sedated with midazolam or diazepam alone or in combination with fentanyl during oral surgery

Midazolam is a new, water-soluble benzodiazepine that has been reported to produce a greater degree of amnesia than does diazepam. This study compares the amnesia produced in patients sedated with midazolam or diazepam or in combination with fentanyl during oral surgery. Twenty-four hours after surgery, each patient answered a questionnaire designed to assess his or her recall of events during and after surgery. Patients who received midazolam alone recalled significantly less than did patients in either diazepam group. The addition of fentanyl to midazolam did not produce any significant difference in recall.     

Nitrous oxide does not aggravate postoperative emesis after orthognathic surgery in female and nonsmoking patients.

PURPOSE: The purpose of this study was to evaluate the effect of supplemental nitrous oxide on postoperative nausea and vomiting (PONV) after propofol anesthesia for orthognathic surgery in female and nonsmoking patients. PATIENTS AND METHODS: We compared PONV in 28 ASA-I female nonsmoking patients undergoing orthognathic surgery. Anesthesia was induced with propofol combined with fentanyl, and tracheal intubation was facilitated with vecuronium. Anesthesia was maintained with propofol with or without nitrous oxide. No patient received neostigmine. PONV was assessed as score 0 (no PONV), score 1 (nausea), and score 2 (vomiting) during the 24-hour recovery period. RESULTS: There were no differences in the patients' characteristics, operation, anesthesia and emergence time, fluid transfusion, blood loss, urine output, and total propofol and fentanyl doses between the 2 groups. There was also no difference in PONV score in 2 groups. Only 1 patient in each group vomited. CONCLUSIONS: It is suggested that supplemental nitrous oxide does not aggravate PONV after propofol anesthesia for orthognathic surgery in female nonsmoking patients.     

Complications of sevoflurane–fentanyl versus midazolam–fentanyl anesthesia in pediatric cleft lip and palate surgery: a randomized comparison study

Careful choice of anesthetic agents in pediatric patients reduces the frequency of anesthesia-related complications. The frequency and type of intraoperative and postoperative complications of sevoflurane–fentanyl versus midazolam–fentanyl anesthesia were compared in 140 consecutive children (aged 3 months to 10 years) undergoing cleft lip and palate repair. Midazolam–fentanyl anesthesia was induced with midazolam (0.05 mg/kg), fentanyl (0.005 mg/kg) and vecuronium (0.1 mg/kg), and maintained with the same agents according to the defined parametars. Sevoflurane–fentanyl anesthesia was induced and maintained with sevoflurane (5–8 vol% and 0.8–1 vol%, respectively) in an oxygen/air mixture and supplemented with fentanyl (0.005 mg/kg). Both groups were comparable in basic demographic data, hemodynamic and respiratory parameters. Difficult intubation occurred in 6 of 76 children (midazolam–fentanyl group) and 4 of 64 children (sevoflurane–fentanyl group) (P = 0.754). Ventricular extrasystole and bronchospasm occurred in one patient each in the sevoflurane–fentanyl group. Postoperatively, emergence agitation was observed in the sevoflurane–fentanyl group (17 cases; P < 0.001); postoperative nausea and vomiting occurred in 2 children (midazolam–fentanyl group) and 3 children (sevoflurane–fentanyl group) (P = 0.660). Midazolam-based anesthesia in children is safer than sevoflurane-based anesthesia regarding occurrence of emergence agitation.     

Use of low-dose ketamine hydrochloride in outpatient oral surgery

This study compares the quality of anesthesia achieved with low-dose ketamine with that of methohexital sodium. In a double-blind study of 40 healthy adult patients undergoing a variety of minor oral surgical procedures, the anesthetic techniques were assessed with respect to the following parameters: patients' subjective evaluation of the anesthesia, the level of response to injection of local anesthetic, psychomotor ability after surgery, recovery times, and the frequency of adverse effects. From these observations, it was deduced that when low-dose ketamine was used with diazepam, meperidine, and nitrous oxide, it proved to be a safe and effective supplement for minimizing pain, discomfort, and anxiety before injection of local anesthetic. Patients' appreciation of the level of anesthetic achieved, psychomotor ability, adverse reactions, and recovery time was not significantly different from the methohexital sodium group.     

Arterial blood gas levels after midazolam or diazepam administered with or without fentanyl as an intravenous sedative for outpatient surgical procedures

The purpose of this study was to compare arterial blood gas measurements made during the baseline, initial sedation, maintenance, and recovery periods in patients sedated with midazolam and saline (MS), midazolam and fentanyl (MF), diazepam and saline (DS), and diazepam and fentanyl (DF). During induction both the MF and the DF groups had significantly lower average PO2, pH, and O2 saturations and significantly higher PCO2 values than either the MS or the DS group. While the differences were not as great, the same was also true during the maintenance phase of the procedure. During recovery, patients receiving MF had lower average PO2, pH, and O2 saturation and higher PCO2 values than the MS or the DF group. Patients receiving MF had significantly lower average PO2, pH, and O2 saturation levels and significantly higher average PCO2 levels during all three postsurgical periods than at baseline. Patients receiving DF had significantly lower average PO2, pH, and O2 saturation levels and significantly higher Pco2 levels during both induction and maintenance than at baseline.