Does functional ability in the postoperative period differ between remifentanil- and fentanyl-based anesthesia?

STUDY OBJECTIVES: To compare patients' functional ability in the 24-hour postoperative period following a remifentanil compared to a hypnotic-fentanyl-treated anesthesia regimen using a 24-Hour Functional Ability Questionnaire. DESIGN: Prospective, 1:1 single-blind, randomized, controlled effectiveness study. SETTING: Multicenter study including 156 hospitals and ambulatory surgery facilities. PATIENTS: 2438 patients (1496 outpatients and 942 inpatients) 18 years of age or older, scheduled for elective surgeries under general endotracheal anesthesia, with an expected duration of unconsciousness of > or =30 minutes. INTERVENTIONS: Patients were randomized to receive either intravenous remifentanil (0.5 microg/kg/min for induction and intubation; with the infusion rate decreased to 0.25 microg/kg/min after intubation) or fentanyl (administered according to anesthesiologists' usual practice) as the opioid during surgery. Concomitant hypnotic drugs were propofol and/or isoflurane (with or without nitrous oxide) titrated according to protocol. Transition analgesia with either morphine or fentanyl was given in the remifentanil patients and at the discretion of the anesthesiologists in the fentanyl patients. MEASUREMENTS: A validated set of measurements of functional ability, rather than more traditional clinical psychological methods, to compare the recovery of patients from remifentanil- and fentanyl-treated anesthetic regimens up to 24 hours after surgery. MAIN RESULTS: Remifentanil was statistically superior to fentanyl for the four functional assessments evaluated: walking without dizziness, thinking clearly, concentration, and communicating effectively. These differences reflect events occurring within the first 24 hours after anesthesia and surgery. CONCLUSIONS: A remifentanil-treated anesthetic demonstrated earlier return to some functions than a fentanyl-treated technique. Although functional assessment is a field that is still in its infancy, a questionnaire to assess functional ability during the 24 hours after anesthesia may provide more practical information about anesthetic recovery than previously used, traditional psychomotor evaluations.

Hemodynamics and emergence profile of remifentanil versus fentanyl prospectively compared in a large population of surgical patients.

STUDY OBJECTIVE: To compare the responses to, and hemodynamics associated with surgical stress, recovery profiles, and anesthesiologists' satisfaction following balanced general anesthesia using either remifentanil or fentanyl in a large-scale population. DESIGN: Prospective, 1:1 single blind, randomized, controlled effectiveness study in which patients received either remifentanil or fentanyl in combination with a hypnotic-based anesthesia regimen of either isoflurane or propofol. SETTING: Multicenter study including 156 hospitals and ambulatory surgery facilities. PATIENTS: 2,438 patients (1,496 outpatients and 942 inpatients), 18 years of age or older, scheduled for elective surgeries under general endotracheal anesthesia, with an expected duration of unconsciousness > or =30 minutes. INTERVENTIONS: Patients were randomized to receive either intravenous (IV) remifentanil (0.5 microg/kg/min for induction and intubation, with the infusion rate decreased to 0.25 microg/kg/min after intubation) or IV fentanyl (administered according to anesthesiologists' usual practice) as the opioid during surgery. Concomitant hypnotic drugs were either propofol and/or isoflurane (with or without nitrous oxide) titrated according to protocol. Transition analgesia with either morphine or fentanyl was given to the remifentanil patients and, at the anesthesiologists' discretion, in the fentanyl patients. MEASUREMENTS: Vital signs, adverse events, and emergence profiles were assessed and recorded. Recovery profile was assessed by recording time spent in the postanesthesia care unit and step-down recovery unit, number and timing of adverse events, timing and dosage of rescue medications, and time to eligibility for discharge (to home or to hospital room). Anesthesiologists' satisfaction with the anesthetic regimen was assessed at the end of surgery. MAIN RESULTS: Remifentanil-treated patients exhibited lower systolic and diastolic blood pressures (by 10-15 mmHg) and lower heart rates (by 10-15 bpm) intraoperatively compared to the fentanyl-treated patients. This difference promptly disappeared on emergence. Remifentanil-treated patients responded to verbal command, left the operating room, and (for outpatients) were discharged home sooner than fentanyl-treated patients. Anesthesiologists rated the predictability of response to intraoperative titration, assessment of hemodynamic profiles, and the quality of anesthesia higher in the remifentanil-treated patients. CONCLUSIONS: This study confirms previous observations on the hemodynamic properties associated with remifentanil and extends these to a wider context than previously reported. These characteristics provide clinicians with an alternative in opioid-based anesthesia.

Is there a learning curve associated with the use of remifentanil?

UNLABELLED: This study prospectively determined whether there was a learning curve with the use of remifentanil, as indicated by decreased hemodynamic variability, improved recovery profile, and decreased incidence of opioid-related adverse events with increasing experience. Patients undergoing diverse surgical procedures (outpatient [n = 1340] and inpatient [n = 560]) were enrolled by investigators (n = 190) who had no previous experience with remifentanil use. Each investigator enrolled 10 patients. A standardized protocol for administration of remifentanil was used. Data were analyzed to determine differences between the first three patients and the last three patients enrolled for each anesthesiologist in the study. There were no differences in hemodynamic variables between the first triad and the last triad in either outpatients or inpatients. Requirements for hypnotic drugs and the doses of remifentanil used were also similar between groups. Analgesic medications administered at the end of surgery and in the postanesthesia care unit (PACU) were similar between groups, except that the last triad in the outpatient group received smaller doses of fentanyl compared with the first triad. Times to response to verbal command, tracheal extubation, and operating room discharge did not differ between groups. However, patients in the last triad undergoing outpatient surgery had shorter times to eligibility for PACU discharge, but times to eligibility for discharge home did not differ. The overall incidence of all adverse events (i.e., hypotension, hypertension, muscle rigidity, respiratory depression, apnea, nausea, and vomiting) was less in the last triad as compared with the first triad. When analyzed separately, only the incidence of vomiting (in the outpatient group) was decreased in the last triad as compared with the first triad. This study suggests that there is a learning curve that aids reduction of minor adverse effects associated with the use of analgesic medications administered at the end of surgery in outpatients, which might have reduced the incidence of postoperative vomiting and the duration of PACU stay. IMPLICATIONS: This study demonstrated that anesthesiologists rapidly acquire the ability to use remifentanil with limited experience. However, there is a learning curve that aids reduction of minor adverse effects associated with the use of analgesic medications administered at the end of surgery in outpatients, which might have reduced the incidence of postoperative vomiting and the duration of postanesthesia care unit stay.

Assessing a tool to measure patient functional ability after outpatient surgery.

UNLABELLED: The "24-Hour Functional Ability Questionnaire" (24hFAQ) was developed to measure final recovery and satisfaction 24 h after surgery. We used structured interviews preoperatively to measure baseline patient concerns, and up to 24 h after discharge, to assess patient function and satisfaction. The primary objective was to assess the validity of the newly developed 24hFAQ in the postoperative outpatient setting. The criteria assessed were 1) CONTENT: comparison with expert opinion and patients' views and response frequency distributions for asymptotes and irrelevance, 2) Construct: contribution of cognitive, physical, and satisfaction domains to postoperative functional ability, 3) Discrimination: comparing mean clinical end points with patient satisfaction, and 4) Criterion (predictive) validity: testing that related constructs are best correlated. CONTENT validity was supported by the appropriate frequency distribution of subject responses, by the lack of floor or ceiling effects, and by <2% of responses indicating irrelevance. Construct validity was supported by moderate-to-strong positive interitem correlations within the cognitive and physical domains as predicted a priori. Discriminant validity support was mixed: key symptoms were associated with adverse patient satisfaction, but operating room and postanesthesia care unit residence times were unrelated. Criterion validity was supported by the finding that preoperative concern with key symptoms was independent of postoperative outcomes. The validity assessment presented was the first assessment of the measurement capability of the 24hFAQ in an outpatient postoperative population. These results provide overall support for the validity of the 24hFAQ for use in outpatient populations. IMPLICATIONS: This study assessed the validity of a novel functional ability questionnaire that measured functional status after recovery from anesthesia and satisfaction 24 h after outpatient surgery. The content, construct, discriminant, and criterion (predictive) validities demonstrated the utility of this assessment instrument in the outpatient setting.

Ketorolac versus fentanyl for postoperative pain management in outpatients.

OBJECTIVE: The purpose of this study was to compare the efficacy and safety of i.v. ketorolac and fentanyl for moderate to severe postoperative pain in patients undergoing elective surgery in an ambulatory surgery unit. DESIGN: A double-blind randomized trial. SETTING: An ambulatory surgery unit in a university-affiliated hospital. PATIENTS: Sixty-nine patients undergoing elective laparoscopy, inguinal hernia repair, or knee arthroscopy were enrolled. INTERVENTION: Patients were randomly assigned to receive intravenous ketorolac 30 mg (n = 38) or fentanyl 50 micrograms (n = 31) for moderate to severe postoperative pain. OUTCOME MEASURES: Pain, assessed using a 100-mm visual analog scale and a 5-point verbal pain scale; adverse effects, as well as vital signs were recorded every 15 min for 150 min or until discharge from the postanesthesia care unit, 6 and 24 h after discharge. RESULTS: Pain reduction on both visual analog and verbal scales was significantly greater with fentanyl than ketorolac at 15 min. In addition, the proportion of patients requiring remedication at the 15-min time point was significantly greater in the ketorolac group. However, there were no significant differences between fentanyl and ketorolac between 30 and 150 min after surgery. Notably, pain reduction was significantly greater with ketorolac on the verbal scale at the 6 h measurement. CONCLUSIONS: Ketorolac appears not be as effective as fentanyl in treating early postoperative pain. Although fentanyl still appears to be the drug of choice in the early postoperative period, the parenteral use of ketorolac was more effective during the later postoperative period in providing longer lasting analgesia.

Midazolam enhances anterograde but not retrograde amnesia in pediatric patients.

BACKGROUND: Midazolam sedation has been shown to diminish recall of one to four cards shown prior to induction of general anesthesia in pediatric patients. This promising but limited finding prompted us to investigate the effect of midazolam sedation on retrograde and anterograde recall and recognition in children scheduled for elective surgery. METHODS: Forty patients aged 4-10 yr were randomized using a double-blind study design to receive either 0.2 mg/kg intranasal midazolam or 0.2 ml/5 kg placebo (distilled water) using a Devilbiss #286 atomizer. To assess postoperative memory of preoperative events, recall and recognition tasks were performed using a series of picture cards designed for this purpose. Retrograde amnesia was measured by postoperative recall and recognition of cards shown prior to midazolam/placebo administration, and anterograde amnesia was measured by postoperative recall and recognition of cards shown during the interval between midazolam/placebo administration and induction of general anesthesia. RESULTS: Compared to placebo, the midazolam group experienced a significant postoperative reduction in ability to both recall (P < .003) and recognize (P < .001) cards shown subsequent to midazolam/placebo administration (anterograde amnesia). In distinction, there was no difference between groups in postoperative ability to recall or recognize cards shown prior to midazolam/placebo administration (retrograde amnesia). CONCLUSIONS: These results support and extend the inference that midazolam diminishes anterograde recall. In addition, our findings indicate that midazolam diminishes anterograde recognition, thereby providing partial anterograde amnesia without affecting retrograde memory in pediatric patients.

Early anesthesia evaluation of the ambulatory surgical patient: does it really help?

STUDY OBJECTIVE: To evaluate whether early evaluation by the anesthesiologist is more beneficial for the ambulatory surgical patient than a day-of-surgery visit. DESIGN: A randomized study evaluating patients with different surgical procedures. SETTING: Ambulatory surgical outpatients at a university-affiliated integrated ambulatory surgical unit. PATIENTS: Sixty-three ASA physical status I and II women scheduled to undergo elective dilatation and curettage or gynecologic laser surgery. INTERVENTIONS: Approximately half of the patients received an early (1 to 7 days preoperative) anesthesia evaluation, and half received a day-of-surgery evaluation. All patients underwent the surgical procedures with a standardized general anesthetic. MEASUREMENTS AND MAIN RESULTS: The effect of an early versus a day-of-surgery anesthesia visit was evaluated with regard to patient anxiety levels; patient satisfaction with the surgical and anesthetic experience; operating room, recovery room, and ambulatory surgery unit time; anesthetic and analgesic requirements; and frequency of postoperative problems within 72 hours at home. There were no differences between the groups in demographic characteristics, anesthesia or analgesic requirements, degree of satisfaction with the ambulatory surgical experience, time spent in recovery room, or frequency of problems on postoperative follow-up. We were unable to demonstrate any differences between those patients seen early versus those seen on the day of surgery in anxiety levels preoperatively and postoperatively. CONCLUSIONS: Healthy ASA physical status I and II ambulatory surgical patients do not benefit from reducing preoperative anxiety by visiting the anesthesiologist prior to the day of surgery.

Escherichia coli deoxyribonucleic acid synthesis mutants: their effect upon bacteriophage P2 and satellite bacteriophage P4 deoxyribonucleic acid synthesis.

Escherichia coli C strains containing different deoxyribonucleic acid (DNA) synthesis mutations have been tested for their support of the DNA synthesis of bacteriophage P2 and its satellite phage P4. Bacteriophage P2 requires functional dnaB, dnaE, and dnaG E. coli gene products for DNA synthesis, whereas it does not require the products of the dnaA, dnaC, or dnaH genes. In contrast, the satellite virus P4 requires functional dnaE and dnaH gene products for DNA synthesis and does not need the products of the dnaA, dnaB, dnaC, and dnaG genes. Thus the P2 and P4 genomes are replicated differently, even though they are packaged in heads made of the same protein.