Patterns and predictors of change in outcome measures in clinical trials in scleroderma: an individual patient meta-analysis of 629 subjects with diffuse cutaneous systemic sclerosis

OBJECTIVE

To examine the range and responsiveness to change of clinical outcome measures and study predictors of clinical response in patients with diffuse cutaneous systemic sclerosis (dcSSc) in the context of clinical trials.

METHODS

Data were combined from 629 patients with dcSSc who participated in 7 multicenter clinical therapeutic trials. Trials used common outcome measures: modified Rodnan skin thickness score (MRSS), Health Assessment Questionnaire disability index (HAQ DI), patient's global assessment of disease activity, pulmonary function tests (forced vital capacity, diffusing capacity for carbon monoxide), hand span, and oral aperture.

RESULTS

The combined database included 629 patients (82% women, mean ± SD age 46.5 ± 11.8 years, mean ± SD disease duration 19.4 ± 15.9 months). Outcomes tended to improve during trials for patients with more severe disease at study entry and to worsen for patients with less severe disease at entry. Disease duration was mildly negatively predictive of change in MRSS at 6 months (r = -0.27, P < 0.001), and substantial bidirectional variation in change in MRSS and HAQ DI score was seen across the spectrum of disease duration. Sixty-three percent of patients with "early" disease (disease duration <18 months) had a decline in MRSS, and 37% had an increase in MRSS. Eighty-one percent of patients with "late" disease (disease duration ≥ 18 months) had a decline in MRSS, and 19% had an increase in MRSS. Multivariate mixed models did not demonstrate that any baseline variables were strongly predictive of subsequent outcome.

CONCLUSION

Among patients with dcSSc enrolled in clinical trials, standard outcome measures tend to improve in those with more severe disease at study entry and to worsen in those with less severe disease at entry. Overall, the MRSS improves during trials, while HAQ DI scores and lung function are mostly static. None of these variables, including disease duration, reliably identifies groups of subjects whose MRSS will predictably increase or decrease in the course of a clinical trial. These findings have important implications for clinical trial design in scleroderma.

Multiple dose pharmacokinetics of oral transmucosal fentanyl citrate in healthy volunteers

BACKGROUND

Oral transmucosal fentanyl citrate (OTFC) is a solid form of fentanyl that delivers the drug through the oral mucosa. The clinical utility of multiple doses of OTFC in the treatment of "breakthrough" cancer pain is under evaluation. The aim of this study was to test the hypothesis that the pharmacokinetics of OTFC do not change with multiple dosing.

METHODS

Twelve healthy adult volunteers received intravenous fentanyl (15 microg/kg) or OTFC (three consecutive doses of 800 microg) on separate study sessions. Arterial blood samples were collected for determination of fentanyl plasma concentration by radioimmunoassay. The descriptive pharmacokinetic parameters (maximum concentration, minimum concentration, and time to maximum concentration) were identified from the raw data and subjected to a nonparametric analysis of variance. Population pharmacokinetic models for all subjects and separate models for each subject were developed to estimate the pharmacokinetic parameters of fentanyl after multiple OTFC doses.

RESULTS

The shapes of the profiles of plasma concentration versus time for each dose of OTFC were grossly similar. No change was noted for maximum concentration or time to maximum concentration over the three doses, while minimum concentration did show a significantly increasing trend. Terminal half-lives for intravenous fentanyl and OTFC were similar. A two-compartment population pharmacokinetic model adequately represented the central tendency of the data from all subjects. Individual subject data were best described by either two- or three-compartment pharmacokinetic models. These models demonstrated rapid and substantial absorption of OTFC that did not change systematically with time and multiple dosing.

CONCLUSIONS

The pharmacokinetics of OTFC were similar among subjects and did not change with multiple dosing. Multiple OTFC dosing regimens within the dosage schedule examined in this study can thus be formulated without concern about nonlinear accumulation.

Buccal absorption of etomidate from a solid formulation in dogs

Etomidate is typically administered i.v. for the induction of general anesthesia. We believe that oral transmucosal absorption may extend etomidate's use to premedication and conscious sedation. Our objective was to study the oral mucosal absorption kinetics and bioavailability of etomidate in a solid dose form in dogs. A solid dose form containing 50 mg of etomidate in sorbitol for buccal administration was prepared. Each dog was administered both i.v. etomidate and buccal etomidate on separate days. Serum etomidate concentrations after i.v. administration were fit to a two-compartment pharmacokinetic model. The rates at which etomidate enters the systemic circulation via buccal mucosal absorption were calculated from serum concentrations from mucosal and i.v. administrations using model-dependent constrained numerical deconvolution. The apparent permeability coefficient and bioavailability were also determined. The mean (+/- SD) maximal serum etomidate concentration after buccal mucosal absorption from the 50-mg dose unit was 239 +/- 79 ng/mL. The time to reach maximal serum concentration was 12.5 +/- 1.8 min. Peak absorption rate of etomidate into the systemic circulation was 832 +/- 417 microg/min. For all dogs, 90% or more of the absorption via buccal mucosa took place during the period in which the drug was in contact with the mucosa (15 min). The apparent transbuccal mucosal permeability coefficient was 9.1 +/- 4.2 x 10(-4) cm/s, higher than values of any other compounds examined. Bioavailability calculated using the area under the serum etomidate concentration versus time curve method and the deconvolution method was 13.6% +/- 10.7% and 16.6% +/- 7.6%, respectively. In conclusion, etomidate is highly permeable through the canine buccal mucosa.

IMPLICATIONS

Etomidate is highly permeable through the canine buccal mucosa. Both the onset and the termination of buccal mucosal absorption of etomidate are rapid, which suggests that titratable delivery of etomidate may be possible by buccal administration.

A Review of Oral Transmucosal Fentanyl Citrate: Potent, Rapid and Noninvasive Opioid Analgesia

The physiochemical characteristics of the potent synthetic opioid agonist fentanyl make it ideal for noninvasive transmucosal delivery. Studies of oral transmucosal fentanyl citrate (OTFC), a candied matrix formulation administered orally as a palatable lozenge on a stick, have investigated and determined this analgesic's pharmacokinetics and pharmacodynamics in a number of clinical settings, including premedication before surgery, acute analgesia for painful medical procedures, and, most recently, for the control of breakthrough cancer pain. The onset to meaningful pain relief in patients with acute pain from surgery or breakthrough pain from cancer is between 5 and 10 minutes after initiating OTFC use, equivalent to intravenous morphine. Analgesic dose equivalency studies suggest that OTFC is, on average, about 10 times more potent than morphine, although, in randomized, controlled, and blinded studies, many patients who were using relatively high doses of opioid anlagesics on an around the- clock schedule for control of cancer pain reported that even a low dose of OTFC (i.e., 200 microg) provided adequate relief from breakthrough pain. Side effects from OTFC are similar in character and frequency to other opioids, including sedation, nausea, and pruritus. These effects appear to wane rapidly with repeated use of this medication. To date there have been no reported serious adverse events in any of the population groups studied or treated with OTFC.

Dose proportionality and pharmacokinetics of oral transmucosal fentanyl citrate

BACKGROUND

The pharmacokinetics of a single dose (15 microg/kg) of oral transmucosal fentanyl citrate (OTFC) have been characterized. A range of doses may eventually be used in clinical practice. The goal of this study was to determine if the pharmacokinetics of OTFC are dose proportional for doses ranging from 200 to 1,600 microg.

METHODS

Twelve healthy male volunteers were studied on four different occasions, receiving 200, 400, 800, and 1,600 microg OTFC in a double-blind, randomized protocol. Venous blood samples were collected at selected times during and after dosing for a 24-h period and assayed for fentanyl using a radioimmunoassay. Maximum concentration, time to maximum concentration, area under the curve, and elimination half-life were determined for each dose administered. In addition, respiratory rate, need for verbal prompting to breathe, and supplemental oxygen requirements were noted.

RESULTS

Mean fentanyl concentration time curves were similarly shaped with increasing doses. Both peak concentrations and area under the curve increased linearly with an increase in dose, whereas time to reach peak serum concentrations did not vary significantly between doses. Except for the 200-microg dose, the apparent elimination half-life remained relatively constant (358-386 min). The incidence of low respiratory rate, supplemental oxygen requirement, and number of breathing prompts significantly increased with increasing doses.

CONCLUSIONS

Oral transmucosal fentanyl citrate exhibits dose-proportional pharmacokinetics over the dose range of 200-1,600 microg.

Oral transmucosal etomidate in volunteers

BACKGROUND

The oral transmucosal route of delivery is now used for many drugs, including fentanyl and midazolam. Etomidate's pharmacokinetic profile and physiochemical properties suggest it may be suitable for transmucosal delivery. Transmucosal delivery might extend etomidate's use to sedation and anxiolysis. This is the first study in humans to examine the oral transmucosal administration of a novel etomidate dosage form.

METHODS

Ten healthy adult volunteers consumed 12.5-mg, 25-mg, 50-mg, and 100-mg doses of oral transmucosal etomidate (OTET) on four different study days. Serum etomidate concentrations, sedation, respiratory and cardiovascular variables, taste, and side effects were determined.

RESULTS

Five minutes after OTET administration, etomidate was detected in the venous blood. Mean peak concentrations occurred 20-30 min later and ranged from 61-174 ng/ml, related to the dose administered. Drowsiness and light sleep occurred in a dose-related manner 10-20 min after administration and lasted for 30-60 min. No episodes of SpO2 <90%, hypotension, or emesis occurred at any dose throughout the study. Nausea was rare. Two volunteers exhibited a brief episode of involuntary tremor after the 100-mg dose. The bitter taste of OTET was judged increasingly unpleasant with escalating doses.

CONCLUSIONS

Oral transmucosal etomidate produces dose-related increases in sedation and clinically significant serum concentrations with minimal side effects. The time course of these effects suggests that OTET might be useful when brief mild to moderate sedation with rapid recovery is desirable. Further development of this novel dosage form is warranted.

A multicenter evaluation of remifentanil for early postoperative analgesia

We evaluated the use of an infusion of remifentanil to provide postoperative analgesia during recovery from total intravenous anesthesia (TIVA) with remifentanil and propofol. One hundred fifty-seven patients from seven medical centers underwent abdominal, spine, joint replacement, or thoracic surgery. Remifentanil was titrated in an effort to limit pain to 0 or 1 on a 0-3 scale. At the end of the 30-min titration period, 78% of infusion rates were in the range of 0.05 to < or = 0.15 microgram.kg-1.min-1, 5% were < 0.05 microgram.kg-1.min-1, and 17% were > 0.15 microgram.kg-1.min-1. Pain scores were 0 or 1 in 64% of patients. Nausea occurred in 35% and emesis in 8% of patients; the peak incidence of nausea followed discontinuation of the remifentanil infusion at the time of administering morphine. Respiratory adverse events (oxygen saturation by pulse oximetry [Spo2] < 90% or respiratory rate < 12) affected 29% of patients. Apnea occurred in 11 patients (7.0%). There was a large variation in the incidence of respiratory depression between the centers, ranging from 0 to 75%. The explanation for the large variability in respiratory outcome was not evident.

Buccal absorption of fentanyl is pH-dependent in dogs

BACKGROUND

Analgesia and sedation have been achieved noninvasively by fentanyl administration through the oral and nasal mucosa. In theory, the transmucosal bioavailability and absorption of fentanyl could be improved by converting more fentanyl to the unionized form by adjusting the surrounding pH. The authors tested this hypothesis in dogs.

METHODS

Under general anesthesia, each of six mongrel dogs was given fentanyl on repeated occasions, first intravenously (once), then by application to the buccal mucosa (six times). Buccal fentanyl administration was accomplished by placement of a pH-buffered solution of fentanyl into a specially constructed cell, which was clamped to the dog's buccal mucosa for 60 min. Fentanyl solutions with pHs of 6.6, 7.2, and 7.7 were studied to span a tenfold difference in the unionized fraction of fentanyl. Femoral arterial blood samples were sampled frequently and analyzed for fentanyl using a radioimmunoassay. Peak plasma concentration and the time of its occurrence for each buccal study were noted from the plasma concentration verses time profile. Terminal elimination half-life, bioavailability, and permeability coefficients were calculated using standard pharmacokinetic techniques.

RESULTS

The variables peak plasma concentration, bioavailability, and permeability coefficient increased three- to fivefold as the pH of the fentanyl buccal solution increased and more fentanyl molecules became unionized. There was no difference in terminal elimination half-life after intravenous fentanyl (244 +/- 68 min) or buccal fentanyl administration (pH 7.7, 205 +/- 89 min; pH 7.2, 205 +/- 65 min; pH 6.6, 196 +/- 48 min). In all buccal studies regardless of pH, time to peak plasma concentration occurred within 10 min of removal of the fentanyl solutions from the buccal mucosa.

CONCLUSIONS

The buccal absorption, bioavailability, and permeability of fentanyl are markedly increased as the pH of the fentanyl solution becomes more basic. Most likely, this is because of an increase in the fraction of unionized fentanyl.

Oral transmucosal fentanyl citrate premedication in patients undergoing outpatient dermatologic procedures

BACKGROUND

Oral transmucosal fentanyl citrate (OTFC) is a novel lozenge dosage form of fentanyl used for premedication. Many dermatology patients undergoing surgical procedures could benefit from such a medication.

OBJECTIVE

The study compared the safety and efficacy of 400-vs 800-micrograms dosage forms for their sedative and anxiolytic effects in adults undergoing a variety of dermatologic outpatient surgical procedures.

METHODS

Patients received OTFC 30 minutes before the procedure. Vital signs, oxygen saturation, sedation, and anxiety scores were measured before OTFC administration and every 15 minutes thereafter.

RESULTS

Significant sedation and anxiolysis developed in both dosage groups. No clinically significant changes in respiratory rate, heart rate, or blood pressure occurred during the study period. Common drug-induced side effects included dizziness, nausea, pruritus, and vomiting.

CONCLUSION

OTFC is safe and effective for outpatient dermatologic procedures; however, the risk of opioid-related side effects must be carefully weighed against the benefits when deciding to use OTFC in an outpatient setting.

Fentanyl-induced rigidity and unconsciousness in human volunteers. Incidence, duration, and plasma concentrations

BACKGROUND

Muscle rigidity frequently accompanies induction of anesthesia with opioids. The authors sought to determine whether unconsciousness and amnesia occur when humans develop rigidity and apnea after intravenous fentanyl (without other concomitant anesthetics).

METHODS

The incidence and duration of rigidity and level of consciousness were evaluated and associated plasma concentrations of fentanyl were measured in 12 healthy adult male volunteers given only intravenous fentanyl. Fentanyl was infused at a rate of 150 micrograms/min until a total of 15 micrograms/kg had been administered. Arterial blood samples for fentanyl assay were drawn and responsiveness, heart rate (HR), and systolic and diastolic arterial blood pressures were determined at frequent intervals during and after infusion. If rigidity was accompanied by an Spo2 < 90%, positive pressure ventilation with 100% O2 with a mask was instituted until spontaneous ventilation resumed.

RESULTS

The incidence of muscular rigidity was 50% (6/12). All subjects who developed rigidity were apneic, unresponsive, and had no recall of commands to breathe or of positive pressure ventilation. Subjects not developing rigidity remained awake and responsive. No subject developing rigidity required neuromuscular blockade to allow positive pressure ventilation and adequate oxygenation (Spo2 > 90%). When rigidity occurred, it started 3 +/- 0.9 (range 1-4) min after the peak plasma fentanyl concentration and lasted for 11.5 +/- 5.8 (range 7-23) min. Rigidity started at a plasma fentanyl concentration of 21.5 +/- 4.4 (range 16-28) ng/ml and ended at 6.9 +/- 1.5 (range 5.2-8.7) ng/ml. Baseline HR was less in the subjects who subsequently developed rigidity (56.7 +/- 7.8 vs. 67.2 +/- 7.8 P = 0.04). No differences in fentanyl plasma concentrations or predicted effect site concentrations for rigidity were detected between subjects who developed rigidity and those who did not.

CONCLUSIONS

These findings support the hypothesis that unconsciousness occurs in the unstimulated subject during fentanyl-induced apnea and rigidity.

Absorption and bioavailability of oral transmucosal fentanyl citrate

Oral transmucosal fentanyl citrate (OTFC) is a novel, noninvasive dosage form of fentanyl used to provide children and adults with sedation, anxiolysis, and analgesia. In order to determine the bioavailability and absorption of fentanyl from OTFC, 12 volunteers were given intravenous fentanyl citrate or OTFC 15 micrograms/kg on each of two occasions. On a third occasion, the authors assessed oral administration (gastrointestinal absorption) by giving eight of the same volunteers the same dose of a solution of fentanyl citrate to swallow. In each study, arterial blood samples were taken over 24 h for analysis of plasma fentanyl. After intravenous (iv) administration of fentanyl, clearance (mean +/- standard deviation) was 0.67 +/- 0.15 l/min; volume of distribution at steady state was 287 +/- 79 l; and the terminal elimination half-life was 425 +/- 102 min. Peak plasma concentrations of fentanyl were higher (3.0 +/- 1.0 vs. 1.6 +/- 0.6 ng/ml, P = 0.01) and occurred sooner (22 +/- 2.5 vs. 101 +/- 48.8 min, P = 0.003) after OTFC than after oral solution administration. Plasma concentrations of fentanyl after OTFC decreased rapidly, to less than 1.0 ng/ml within 75-135 min after the beginning of administration. Peak absorption rate was greater (11.1 +/- 4.3 vs. 3.6 +/- 2.1 micrograms/min, P = 0.004) and occurred much sooner after OTFC than after oral solution administration (19 +/- 2.6 vs. 87.5 +/- 38.1 min, P = 0.001). Systemic bioavailability was greater after OTFC administration than after the oral solution (0.52 +/- 0.1 vs. 0.32 +/- 0.1, P = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Oral transmucosal fentanyl citrate for premedication in paediatric outpatients

Two doses (10-15 micrograms.kg-1, Group I, and 15-20 micrograms.kg-1, Group II) of oral transmucosal fentanyl citrate (OTFC) plus a placebo (Group III) were evaluated for premedication in 105 healthy children, aged 2 to 13 yr, undergoing short (less than 1 hr) operations in the hospital short-stay unit. The study was randomized and double-blinded and 91 of the 105 children also received droperidol, 25 micrograms.kg-1 IV, after induction of anaesthesia with halothane and N2O in oxygen. Both doses of OTFC produced significantly greater sedation (first present at 20 min) and anxiolysis (first present in Group I at 40 min) than the placebo. Recovery times were similar in the three groups and analgesic requirements in the recovery room were significantly lower in Group I than Group III. Both OTFC groups took longer to tolerate oral fluids in the postoperative discharge unit than the placebo group and this caused patients in Group I to have a delayed discharge from the hospital compared to Group III. Preoperative pruritus occurred significantly more frequently in Groups I and II (58 and 76 per cent, respectively) than Group III (23 per cent). Although the incidences of nausea and vomiting tended to be slightly higher in the OTFC groups in the preoperative holding and postoperative discharge units, the differences among the groups were not statistically significant. Likewise droperidol did not reduce the incidence of postoperative nausea or vomiting. The data indicate that OTFC may be a safe and effective premedicant in paediatric patients having short operations but delays discharge from the hospital (by 30-50 min) by delaying the time patients tolerate fluids early after operation.

Transdermal scopolamine reduces nausea and vomiting after outpatient laparoscopy

The authors evaluated the effect of transdermal scopolamine on the incidence of postoperative nausea, retching, and vomiting after outpatient laparoscopy in a double-blind, placebo-controlled study. A Band-Aid-like patch containing either scopolamine or placebo was placed behind the ear the night before surgery. Anesthesia was induced with fentanyl (0.5-2 micrograms/kg iv), thiopental (3-5 mg/kg iv), and succinylcholine (1-1.5 mg/kg iv) and maintained with isoflurane (0.2-2%) and nitrous oxide (60%) in oxygen. Scopolamine-treated patients had less nausea, retching, and vomiting compared with placebo-treated patients (P = 0.0029). Severe nausea and/or vomiting was present in 62% of the placebo group but only 37% of those getting the scopolamine patch. Repeated episodes of retching and vomiting were also less frequent in the scopolamine group compared with the placebo group (23% vs. 41%; P = 0.0213) as was the need for additional antiemetic therapy (13% vs. 32%; P = 0.0013). Patients in the scopolamine group were also discharged from the hospital sooner (4 +/- 1.3 vs. 4.5 +/- 1.5 h; P = 0.0487). Side effects were more frequent among those patients treated with the scopolamine patch (91% vs. 45%; P less than 0.05) but were not troublesome. The authors conclude that transdermal scopolamine is a safe and effective antiemetic for outpatients undergoing laparoscopy.

Differences in magnitude and duration of opioid-induced respiratory depression and analgesia with fentanyl and sufentanil

The magnitude and duration of analgesia and respiratory depression induced by fentanyl (1.0, 2.0, and 4.0 micrograms/kg) and sufentanil (0.1, 0.2, and 0.4 microgram/kg) after intravenous administration over 30 s were measured in 30 healthy young adult male volunteers divided into three groups and studied in a double-blind, randomized fashion. Each volunteer received one dose of fentanyl or sufentanil and no sooner than 48 h later, the corresponding equipotent dose of the other opioid. End-tidal CO2 and ventilatory and occlusion pressure responses to CO2 rebreathing were used to measure drug-induced respiratory effects. Analgesic effects were assessed by changes in the pain threshold to electric shock applied to the forearm. Plasma levels of fentanyl and sufentanil were measured by radioimmunoassay. Testing and sampling intervals were 5, 30, 60, 90, 120, 240, 300, and 360 min after drug administration. The magnitude and duration of depression of the ventilatory and occlusion pressure response were significantly less with sufentanil compared with fentanyl, irrespective of dose. Ventilatory and occlusion pressure responses returned to control values by 30 and 30 min, respectively, after sufentanil and by 240 and 120 min, respectively, after fentanyl. Statistically significant elevations of the pain threshold were, however, greater and longer lasting after sufentanil compared with fentanyl. Pain threshold returned to control values 180 min after sufentanil but only 90 min after fentanyl. These results suggest that sufentanil may provide better patient comfort with less respiratory depression than does fentanyl.

Oral transmucosal fentanyl citrate (lollipop) premedication in human volunteers

The authors determined whether fentanyl incorporated into a candy lollipop, oral transmucosal fentanyl citrate (OTFC), would cross mucosal tissues of the mouth in sufficient quantities during and after dissolution to produce sedation and/or analgesia. Associated respiratory and circulatory changes, side effects, and plasma concentrations of fentanyl were also measured. The evaluations were done in 28 adult volunteers who received fentanyl citrate in doses of 5, 4, 2, 1, and 0.5 mg in OTFC and rapidly sucked the lollipops (N = 20) or allowed them to passively dissolve (N = 8). Rapid consumption of OTFC resulted in more rapid onset of a pleasant feeling (first subjective sensation) but not more rapid onset of objective sedation or analgesia than passive dissolution. There was a significant correlation between dose of OTFC and magnitude of sedation (P less than 0.001, Spearman rank correlation = -0.82). Higher doses of OTFC produced greater and longer lasting analgesia and respiratory depression and a higher incidence of nausea and vomiting than lower doses, but pruritus (33%-87%) was not related to the dose of OTFC. Heart rate and arterial blood pressures were not changed by any dose of OTFC. The data indicate that low doses of OTFC (0.5 and 1 mg, equivalent to 5-20 micrograms.kg-1 of fentanyl citrate) produce analgesia and sedation with minimal side effects and little respiratory depression in adult volunteers and deserve further evaluation in patients.

Oral transmucosal fentanyl citrate premedication in children

The authors evaluated the safety and efficacy of four doses of oral transmucosal fentanyl citrate (OTFC) as a premedicant in 44 children about to undergo elective operations. The patients received 5-10, 10-15, 15-20, or 20-25 micrograms.kg-1 of OTFC in the holding area and had activity (sedation) scores, vital signs (including systolic and diastolic arterial blood pressures, heart, and respiratory rates), and pulse oximetry determined oxygen saturation measured before and at 15-min intervals after premedication until they were taken to the operating room. Cooperation during anesthetic induction, and quality and speed of recovery room emergence were measured and side effects noted. OTFC was readily accepted and provided significant (dose dependent) reductions in preoperative activity starting after 30 min. Onset of sedation was related to dose of OTFC but time to peak effect was not. Vital signs remained unchanged preoperatively in all groups but patients receiving 20-25 micrograms.kg-1 had oxygen saturations that were significantly lower than patients in the other groups 30 min after beginning OTFC consumption. Three of the 12 patients receiving the highest dose of OTFC experienced transient oxygen saturation less than 90% which, however, was easily treated by commands to take a breath. Anesthetic inductions were rated good or excellent in 80% of the patients and recovery times were similar irrespective of the OTFC dose. OTFC caused dose-independent preoperative pruritus in 90% or more of patients and pruritus (33%-70%), nausea (30%-58%), and vomiting (50%-83%) postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of oral transmucosal fentanyl citrate and an oral solution of meperidine, diazepam, and atropine for premedication in children

The safety and efficacy of premedication with oral transmucosal fentanyl citrate (OTFC) was compared with that of an orally administered solution of meperidine, diazepam, and atropine and no premedication in 59 children about to undergo elective operations. The patients were randomly assigned to receive no premedication (n = 19); 0.25 ml/kg of the oral solution (containing meperidine, 1.5 mg/kg, diazepam, 0.2 mg/kg, and atropine, 0.02 mg/kg, n = 20); or OTFC (15-20 micrograms/kg, n = 20). Children had activity (sedation) and anxiety scores, vital signs (including systolic and diastolic arterial blood pressures and heart and respiratory rates) and pulse oximetry determined oxygen saturation measured before and at 10-min intervals after premedication until they were taken to the operating room. Quality of induction and recovery was evaluated using scoring schedules; recovery times were measured and side effects noted. OTFC was readily accepted and provided significant reductions in preoperative activity (sedation) and anxiety starting after 30 min. After OTFC, sedation and anxiolysis were significantly greater than in children having no premedication but similar to children having the oral solution for premedication. Vital signs and oxygen saturations remained unchanged preoperatively in all groups. Induction and recovery evaluations and recovery times were similar in the three groups, although children having OTFC had the lowest requirements for narcotics in the recovery room. OTFC caused an 80% incidence of mild preoperative facial pruritus and a higher overall incidence of postoperative vomiting (37%) than premedication with the oral solution (5%) or no premedication (18%).(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of computer-controlled versus manual administration of vecuronium in humans

The short elimination half-life of vecuronium suggests it may be delivered more efficiently by continuous infusion than by traditional bolus injections. The objective of this study was to compare manual administration with computer-controlled administration. Anesthesia was induced in 22 patients (American Society of Anesthesiologists [ASA] physical status I and II) with fentanyl and sodium thiopental and maintained with halothane and nitrous oxide in oxygen. Neuromuscular function was assessed at the hypothenar eminence and the adductor pollicis (train-of-four stimulation). A bolus of 0.1 mg/kg of vecuronium was given to obtain 100% twitch depression for tracheal intubation. After twitch height returned to 25% of control, relaxation was maintained by traditional bolus injections (group 1, n = 7), manually controlled continuous infusion (group 2, n = 7), or computer-controlled continuous infusion (group 3, n = 8). In all three groups the desired level of relaxation was 90% twitch depression. Variability of relaxation differed significantly among the three groups (group 1: 10.5%, group 2: 12.4%, group 3: 7.1%). Twitch height was more constant with computer control than with either bolus injections or manual infusion (P less than 0.05). There was no statistically significant difference in the drug requirement (group 1: 1.60 microgram/kg/min, group 2: 1.51 microgram/kg/min, group 3: 1.45 microgram/kg/min). Variability in the mechanomyogram (n = 12) was much higher than in the electromyogram (n = 10). Computer-controlled infusion may be a useful adjunct for the anesthesiologist who desires a stable level of patient relaxation when using short-acting, non-depolarizing relaxants.

Pulmonary arterial catheterization before anesthesia in patients undergoing cardiac surgery. Placement of the pulmonary arterial catheter before anesthesia for cardiac surgery: safe, intelligent, and appropriate use of invasive hemodynamic monitoring

Should one catheterize the pulmonary artery (PA) for cardiac surgery before or after induction of anesthesia? Issues of central importance to this question include (1) the patient's preexisting hemodynamic abnormalities, (2) cardiovascular effects of anesthetic induction drugs, and (3) hemodynamic stress caused by laryngoscopy, endotracheal intubation, and PA catheter insertion. Some clinicians use the PA catheter immediately before anesthetic induction to detect and correct acute abnormalities in preload and ventricular function. This approach has been described as being partially responsible for decreased morbidity and mortality in patients with cardiovascular disease. Hemodynamic instability during induction has been reported with many of the common anesthetic induction agents, especially in patients with poor ventricular function. Since blood pressure is the product of cardiac output and systemic vascular resistance, accurate interpretation and treatment of hypotension are possible only when these variables are provided by vigorous use of the PA catheter. Early detection of myocardial ischemia is possible with examination of acute changes in the pulmonary capillary wedge pressure tracing. However, the lack of such information can restrict even the best anesthetist. Insertion of the PA catheter in the awake patient can be accomplished effectively and with minimal risk, so long as good patient rapport, adequate premedication, and continuation of antianginal medication until the time of surgery are assured. Preinduction placement of the PA catheter provides valuable, objective information for the cardiac anesthesiologist without incurring significant risk to the patient.