Inducción TCI a sitio efector de propofol: evaluación clínica de dos diferentes ke0 / TCI induction to propofol effect site: clinical evaluation of two different ke0s

Comparamos el comportamiento clínico y electroencefalográfico del modelo farmacocinético de Marsh para propofol con dos distintas constantes de equilibrio a sitio efector (ke0), actualmente incorporadas a las infusoras comerciales. Con una base de remifentanil estable, propusimos una concentración de propofol que representase la CE95 anestésico para ambos fármacos simultáneos (2,8 mcg/ml). Esta concentración, con el valor de ke0 del modelo de Marsh incorporado al Diprifusor, hizo perder la conciencia a los pacientes a 1 mcg/ml y permitió alcanzar el estado hipnótico (AAI AEP menor que 40) con el bolo inicial a una Ce calculada de 2 mcg/ml. En cambio, el ke0 incorporado en la infusora Primea Orchestra requirió al menos 30 por ciento más de fármaco en el bolo de carga para alcanzar un AEP menor que 40, definido como objetivo clínico de hipnosis, habiendo ya alcanzado el equilibrio plasma/efecto. Esta diferencia en el valor del ke0 de la infusora Primea Orchestra genera confusión sobre la utilidad del valor de guía clínica de la Ce calculada; además, el valor ke0 incorporado al Diprifusor limita el modo de inducción a dianas sitio efecto bajas (menores de 3,5 mcg/ml) debido a la gran masa de fármaco que infunde en la carga.

Inducción TCI a sitio efector de propofol: evaluación clínica de dos diferentes ke0 / TCI induction to propofol effect site: clinical evaluation of two different ke0s

Comparamos el comportamiento clínico y electroencefalográfico del modelo farmacocinético de Marsh para propofol con dos distintas constantes de equilibrio a sitio efector (ke0), actualmente incorporadas a las infusoras comerciales. Con una base de remifentanil estable, propusimos una concentración de propofol que representase la CE95 anestésico para ambos fármacos simultáneos (2,8 mcg/ml). Esta concentración, con el valor de ke0 del modelo de Marsh incorporado al Diprifusor, hizo perder la conciencia a los pacientes a 1 mcg/ml y permitió alcanzar el estado hipnótico (AAI AEP menor que 40) con el bolo inicial a una Ce calculada de 2 mcg/ml. En cambio, el ke0 incorporado en la infusora Primea Orchestra requirió al menos 30 por ciento más de fármaco en el bolo de carga para alcanzar un AEP menor que 40, definido como objetivo clínico de hipnosis, habiendo ya alcanzado el equilibrio plasma/efecto. Esta diferencia en el valor del ke0 de la infusora Primea Orchestra genera confusión sobre la utilidad del valor de guía clínica de la Ce calculada; además, el valor ke0 incorporado al Diprifusor limita el modo de inducción a dianas sitio efecto bajas (menores de 3,5 mcg/ml) debido a la gran masa de fármaco que infunde en la carga. (AU)

Efficacy and safety of fast-track recovery strategy for patients undergoing laparoscopic nephrectomy.

BACKGROUND AND PURPOSE: Factors that adversely affect early recovery after major laparoscopic procedures include ileus, pain, nausea, emesis, and fatigue. The objective of this randomized controlled study was to evaluate the impact of a multimodal fast-track (FT) rehabilitation program on recovery and length of hospital stay after laparoscopic nephrectomy. PATIENTS AND METHODS: Thirty patients undergoing laparoscopic nephrectomy received either conventional care (control) or an FT recovery program. All patients received a standardized anesthetic technique and patient- controlled analgesia (morphine) for postoperative pain control. In the FT group, patients received premedication with rofecoxib and ranitidine, local anesthesia was administered at the ports and renal fosa during surgery, and postoperative non-opioid analgesic and gastrokinetic drugs were administered as part of an early enteral nutrition and mobilization program. During the postoperative period, pain and nausea were assessed at specific time intervals. In addition, recovery room and hospital discharge times, the need for rescue analgesics and antiemetics, patient satisfaction with pain management and quality of recovery, and side effects were recorded daily for 3 days after surgery. Patients were discharged home when they met previously defined discharge criteria. RESULTS: The FT group was discharged earlier from the recovery room (74+/-23 v 103+/-47 minutes) and the hospital (41+/-11 v 59+/-11 hours). Pain and nausea scores were consistently lower in the FT group during the first 48 hours after surgery. In addition, the requirement for antiemetic rescue therapy during the first 24 hours was reduced in the FT group (15% v 58%). The FT group also received less morphine during the first 2 postoperative days (14+/-16 v 40+/-24 mg). Finally, patient satisfaction with postoperative pain control was significantly higher in the FT group. CONCLUSIONS: A multimodal approach to minimizing postoperative side effects led to a reduced recovery room and hospital stay, as well as better pain control and patient satisfaction after laparoscopic nephrectomy.

Heated and humidified insufflation during laparoscopic gastric bypass surgery: effect on temperature, postoperative pain, and recovery outcomes.

BACKGROUND: Controversy exists regarding the efficacy of heated and humidified intraperitoneal gases in maintaining core body temperature. We performed a sham-controlled study to test the hypothesis that active warming and humidification of the insufflation gas reduces intraoperative heat loss and improves recovery outcomes. PATIENTS AND METHODS: Fifty morbidly obese patients undergoing laparoscopic Roux-en-Y gastric bypass procedures using a standardized anesthetic technique were randomly assigned to either a control (sham) group receiving room temperature insufflation gases with an inactive Insuflow (Lexion Medical, St. Paul, MN) device, or an active (Insuflow) group receiving warmed and humidified intraperitoneal gases. Esophageal and/or tympanic membrane temperature was measured perioperatively. Postoperative pain was assessed at 15 minute intervals using an 11-point verbal rating scale, with 0 = none to 10 = maximal. In addition, postoperative opioid requirements, incidence of nausea and vomiting, as well as the quality of recovery, were recorded. RESULTS: Use of the active Insuflow device was associated with significantly higher mean +/- standard deviation (SD) intraoperative core body temperatures (35.5 +/- 0.5 vs. 35.0 +/- 0.4 degrees C). Postoperative shivering (0 vs. 19%) and the requirement for morphine in the postanesthesia care unit (5 +/- 4 vs. 10 +/- 5 mg) were both significantly lower in the Insuflow vs. control groups. Patients in the Insuflow group also reported a higher quality of recovery 48 hours after surgery (15 vs. 13, P < 0.05). CONCLUSION: The Insuflow device modestly reduced shivering and heat loss, as well as the need for opioid analgesics in the early postoperative period. However, it failed to improve laparoscopic visualization due to fogging, and provided improvement in the quality of recovery only on postoperative day 2.

Optimal timing of acustimulation for antiemetic prophylaxis as an adjunct to ondansetron in patients undergoing plastic surgery.

We designed this study to evaluate the antiemetic efficacy of transcutaneous electrical acupoint stimulation in combination with ondansetron when applied before, after, or both before and after plastic surgery. A randomized, double-blind, sham-controlled study design was used to compare three prophylactic acustimulation treatment schedules: preoperative--an active device was applied for 30 min before and a sham device for 72 h after surgery; postoperative--a sham device was applied for 30 min before and an active device for 72 h after surgery; and perioperative--an active device was applied for 30 min before and 72 h after surgery (n = 35 per group). All patients received a standardized general anesthetic, and ondansetron 4 mg IV was administered at the end of surgery. The incidence of vomiting/retching and the need for rescue antiemetics were determined at specific time intervals for up to 72 h after surgery. Nausea scores were recorded with an 11-point verbal rating scale. Other outcome variables assessed included discharge times (for outpatients), resumption of normal activities of daily living, complete antiemetic response rate, and patient satisfaction with antiemetic therapy and quality of recovery. Perioperative use of the ReliefBand significantly increased complete responses (68%) compared with use of the device before surgery only (43%). Median postoperative nausea scores were significantly reduced in the peri- and postoperative (versus preoperative) treatment groups. Finally, patient satisfaction with the quality of recovery (83 +/- 16 and 85 +/- 13 vs 72 +/- 18) and antiemetic management (96 +/- 9 and 94 +/- 10 vs 86 +/- 13) on an arbitrary scale from 0 = worst to 100 = best was significantly higher in the groups receiving peri- or postoperative (versus preoperative) acustimulation therapy. For patients discharged on the day of surgery, the time to home readiness was significantly reduced (114 +/- 41 min versus 164 +/- 50 min; P < 0.05) when acustimulation was administered perioperatively (versus preoperatively). In conclusion, acustimulation with the ReliefBand was most effective in reducing postoperative nausea and vomiting and improving patients' satisfaction with their antiemetic therapy when it was administered after surgery.

The pharmacodynamic effects of a lower-lipid emulsion of propofol: a comparison with the standard propofol emulsion.

UNLABELLED: Using a randomized, double-blind protocol design, we compared a new lower-lipid emulsion of propofol (Ampofol) containing propofol 1%, soybean oil 5%, and egg lecithin 0.6% with the most commonly used formulation of propofol (Diprivan) with respect to onset of action and recovery profiles, as well as intraoperative efficacy, when administered for induction and maintenance of general anesthesia as part of a "balanced" anesthetic technique in 63 healthy outpatients. Anesthesia was induced with sufentanil 0.1 microg/kg (or fentanyl 1 microg/kg) and propofol 2 mg/kg IV and maintained with a variable-rate propofol infusion, 120-200 microg x kg(-1) x min(-1). Onset times to loss of the eyelash reflex and dropping a syringe were recorded. Severity of pain on injection, speed of induction, intraoperative hemodynamic variables, and electroencephalographic bispectral index values were assessed. Recovery times to opening eyes and orientation were noted. The results demonstrated that there were no significant differences between Ampofol and Diprivan with respect to onset times, speed of induction, anesthetic dose requirements, bispectral index values, hemodynamic variables, recovery variables, or patient satisfaction. However, the incidence of pain on injection was more frequent in the Ampofol group (26% versus 6%, P < 0.05). We conclude that Ampofol is equipotent to Diprivan with respect to its anesthetic properties but was associated with a more frequent incidence of mild pain on injection. IMPLICATIONS: The pharmacodynamic profile of a lower-lipid containing emulsion of propofol (Ampofol) was compared with Diprivan when administered for induction and maintenance of general anesthesia. This preliminary study demonstrated that the two formulations of propofol were equivalent with respect to their induction and maintenance properties. However, Ampofol was associated with a more frequent incidence of pain on injection.

The effect of cerebral monitoring on recovery after general anesthesia: a comparison of the auditory evoked potential and bispectral index devices with standard clinical practice.

UNLABELLED: The use of cerebral monitoring may improve the ability of anesthesiologists to titrate anesthetic drugs. However, there is controversy regarding the impact of the alleged anesthetic-sparing effects of cerebral monitoring on the recovery process and patient outcome. We designed this prospective double-blinded, sham-controlled study to evaluate the impact of intraoperative monitoring with the electroencephalogram bispectral index (BIS) or auditory evoked potential (AEP) device on the usage of desflurane and the time to discharge from the recovery room, as well as on patient satisfaction with their anesthetic experience and recovery. Ninety healthy patients undergoing laparoscopic general surgery procedures using a standardized anesthetic technique were randomly assigned to one of three monitoring groups: standard clinical practice (control), BIS-guided, or AEP-guided. Both the BIS and AEP monitors were connected to all patients before induction of general anesthesia. In the control group, the anesthesiologists were not permitted to observe the BIS or AEP index values during the intraoperative period. In the BIS-guided group, the volatile anesthetic was titrated to maintain a BIS value in the range of 45-55. In the AEP-guided group, the targeted AEP index range was 15-20. The BIS and AEP indices, as well as end-tidal desflurane concentration, were recorded at 3-5 min intervals. Recovery times to awakening, tracheal extubation, fast-track score >or=12, and postanesthesia care unit (PACU) discharge criteria were recorded at 1-10 min intervals. In addition, patient satisfaction with anesthesia and quality of recovery were evaluated on 100- and 18-point scales, respectively, at 24 h after surgery. The AEP- and BIS-guided groups were administered significantly smaller average end-tidal desflurane concentrations than the control group (3.8 +/- 0.9 and 3.9 +/- 0.6 versus 4.7 +/- 1.7, respectively) (P < 0.01). Although the emergence times to eye opening, tracheal extubation, and obeying commands were consistently shorter in the AEP and BIS groups (6 +/- 4 and 6 +/- 5 versus 8 +/- 8 min; 6 +/- 5 and 6 +/- 4 versus 11 +/- 10 min; and 8 +/- 4 and 7 +/- 4 versus 12 +/- 9 min, respectively), only the extubation times were significantly different from the control group (P < 0.05). More importantly, the length of the PACU stay was significantly shorter in both the AEP- and BIS-guided groups (79 +/- 43 and 80 +/- 47 versus 108 +/- 58 min, respectively) (P < 0.05). The patients' quality of recovery was also significantly higher in the two monitored groups (15 +/- 2 versus 13 +/- 3 in the control group, P < 0.05). We concluded that cerebral monitoring with either the BIS or AEP devices reduced the maintenance anesthetic (desflurane) requirement, resulting in a shorter length of stay in the PACU and improved quality of recovery after laparoscopic surgery. However, there were no significant outcome differences between the two cerebral monitored groups. IMPLICATIONS: Compared with standard monitoring practices, use of an auditory evoked potential or bispectral index monitor to titrate the volatile anesthetic led to a significant reduction in the anesthetic requirement. The anesthetic-sparing effect of cerebral monitoring resulted in a shorter postanesthesia care unit stay and improved quality of recovery from the patient's perspective.

Effect of auditory evoked potential index monitoring on anesthetic drug requirements and recovery profile after laparoscopic surgery: a clinical utility study.

BACKGROUND: The auditory evoked potential (AEP) monitor provides an electroencephalogram-derived index (AAI) that has been reported to correlate with the central nervous system depressant effects of anesthetic drugs. This clinical utility study was designed to test the hypothesis that AAI-guided administration of the maintenance anesthetics and analgesics would improve their titration and thereby provide a faster recovery from general anesthesia. METHODS: Seventy consenting patients undergoing elective general surgery procedures were randomly assigned to either a control (standard clinical practice) or AEP-monitored group. Although the AEP monitor was connected to all patients, the information from the monitor was only made available to the anesthesiologists assigned to patients in the AEP-monitored group. In the AEP-monitored group, the inspired desflurane concentration was titrated to maintain an AAI value of 15-20. In the control group, the inspired desflurane concentration was varied based on standard clinical signs. The AAI values and hemodynamic variables, as well as end-tidal desflurane concentrations, were recorded at 3- to 5-min intervals. The recovery times to achieve a White fast-track score greater than 12 and an Aldrete score of 10, as well as the actual duration of the PACU stay, were evaluated at 5- to 10-min intervals. Patient satisfaction with recovery from anesthesia was assessed using a 100-point verbal rating scale at 24 h after surgery. RESULTS: The average intraoperative AAI value in the AEP-monitored group was significantly higher than in the control group (16 +/- 5 vs. 11 +/- 8, P < 0.05). Use of the AEP monitor reduced the desflurane requirement by 26% compared to the control group (P < 0.01). In addition, the AEP-monitored group received less intraoperative fentanyl (270 +/- 120 vs. 390 +/- 203 microg, P < 0.05) and more rapidly achieved fast-track eligibility (29 +/- 19 vs. 56 +/- 41 min, P < 0.05). The time required to achieve an Aldrete score of 10 (60 +/- 31 vs. 98 +/- 55 min) and the duration of stay in the recovery room (78 +/- 32 vs. 106 +/- 54 min) were also significantly reduced in the AEP-monitored (vs. control) group (P < 0.05). CONCLUSION: Use of AEP monitoring as an adjunct to standard clinical monitors improved titration of anesthetic drugs, thereby facilitating the early recovery process after laparoscopic surgery.

The efficacy of celecoxib premedication on postoperative pain and recovery times after ambulatory surgery: a dose-ranging study.

UNLABELLED: Recently, the Food and Drug Administration increased the celecoxib dosage recommendation from 200 mg to 400 mg for acute pain management. No studies have directly compared the analgesic efficacy of different doses of celecoxib for the prevention of postoperative pain. In this prospective, double-blinded, placebo-controlled study, we compared oral celecoxib 200 mg to 400 mg when administered for premedication of outpatients undergoing minor ear-nose-throat surgery. A total of 93 healthy outpatients were assigned to 1 of 3 study groups: control (placebo; n = 30), celecoxib 200 mg (n = 30), or celecoxib 400 mg (n = 33). The study drug was given orally 30-45 min before surgery, and all patients received a standardized general anesthetic technique. During the postoperative period, pain scores (0-10), recovery times, the need for rescue analgesics, quality of recovery (0-100), patient satisfaction with pain management (0-100), and side effects were recorded. Pain was assessed at 30-min intervals using a verbal rating scale, with 0 = no pain to 10 = worst pain imaginable, in the postanesthesia care unit and day surgery unit recovery areas and at 24 h after surgery. Celecoxib 400 mg was significantly more effective than 200 mg (and placebo) in reducing postoperative pain. Both celecoxib 200 mg and 400 mg were more effective than placebo in reducing the postoperative fentanyl requirement (74 +/- 67 micro g and 56 +/- 62 micro g versus 120 +/- 86 micro g, respectively). The larger dose of celecoxib significantly reduced the percentage of patients with severe pain at discharge (6% versus 37% and 30% in the celecoxib 200 mg and control groups, respectively). The median number of doses of oral analgesic medication after discharge was also significantly reduced in the celecoxib 400 mg group (0 versus 2 and 2 in the celecoxib 200 mg and control groups, respectively). However, no differences were found among the three study groups with respect to recovery times and secondary outcome variables (e.g., patient satisfaction and quality of recovery). We conclude that oral premedication with celecoxib 400 mg was more effective than 200 mg in reducing severe postoperative pain and the need for rescue analgesic medication in the postoperative period. IMPLICATIONS: Oral premedication with celecoxib 400 mg was more effective than 200 mg in reducing postoperative pain and the need for rescue analgesic medication in the early postoperative period. However, neither dose of celecoxib was more effective than a placebo in facilitating the recovery process after outpatient surgery.

Can the bispectral index be used to predict seizure time and awakening after electroconvulsive therapy?

UNLABELLED: The electroencephalogram (EEG) bispectral index (BIS) measures the hypnotic component of the anesthetic state and correlates with emergence from general anesthesia. Therefore, we hypothesized that the BIS would be useful in predicting electroconvulsive therapy (ECT)-induced seizure times and awakening from methohexital anesthesia. Twenty-five consenting patients with major depressive disorders underwent 100 maintenance ECT treatments. All patients were premedicated with glycopyrrolate 0.2 mg IV, and anesthesia was induced with methohexital 1 mg/kg IV. The BIS was monitored continuously, and the values were recorded at specific end-points, including before anesthesia (baseline), after the induction of anesthesia (pre-ECT), at the end of ECT (peak), after ECT (suppression), and on awakening (eye opening). The pre-ECT BIS value correlated with the duration of both the motor (r = 0.3) and EEG (r = 0.4) seizure activity (P < 0.05). The peak post-ECT BIS value correlated with the duration of the EEG seizure activity (r = 0.5) (P < 0.05). A positive correlation was also found between the EEG seizure duration and the time to eye opening (r = 0.4) (P < 0.05). However, the BIS values on awakening from methohexital anesthesia varied from 29 to 97 and were <60 in 75% of the cases. We conclude that the BIS value before the ECT stimulus is applied could be useful in predicting the seizure time. However, the BIS values on awakening were highly variable, suggesting that it reflects both the residual depressant effects of methohexital and post-ictal depression. IMPLICATIONS: The bispectral index (BIS) value immediately before the electroconvulsive therapy (ECT) stimulus correlates with the duration of the motor and electroencephalogram (EEG) seizure activity during methohexital anesthesia. In addition, the increase in the BIS value during the ECT-induced seizure was proportional to the duration of EEG seizure activity. However, the BIS value on awakening from anesthesia varied widely, from 29 to 97.

The effect of remifentanil on seizure duration and acute hemodynamic responses to electroconvulsive therapy.

UNLABELLED: We designed this prospective, randomized, double-blinded, placebo-controlled, crossover study to evaluate the effect of different doses of remifentanil on the acute hemodynamic response and duration of seizure activity after a standardized electroconvulsive therapy (ECT) stimulus. Twenty consenting patients with major depressive disorders receiving maintenance ECT participated in this study. Eighty ECT treatments were evaluated. All patients were premedicated with glycopyrrolate 0.2 mg IV, unconsciousness was induced with methohexital 1 mg/kg IV, and muscle paralysis was produced with succinylcholine 1.2 mg/kg IV. Subsequently, patients received 1 of 3 different doses of remifentanil 25, 50, and 100 microg or saline (control) in a random sequence immediately after methohexital at 4 consecutive ECT treatments. Labetalol, in 5-mg IV boluses, was used as a rescue antihypertensive medication. A fixed suprathreshold electrical stimulus was administered to elicit a seizure, and the times from the stimulus to the cessation of the motor and electroencephalographic (EEG) seizure activity were noted. Pre- and post-ECT blood pressure values were significantly decreased in the 100- microg remifentanil group compared with the control group. The durations of motor (38 +/- 9 s to 43 +/- 15 s) and EEG (55 +/- 29 s to 60 +/- 21 s) seizure activity were not significantly different among the four groups. Similarly, recovery times to eye opening, obeying commands, and discharge from the recovery room did not differ among the four study groups. The requirement for labetalol after ECT was nonsignificantly decreased in the remifentanil groups. In conclusion, remifentanil 100 microg IV attenuated the acute hemodynamic response to ECT. Furthermore, remifentanil had no adverse effect on the duration of ECT-induced seizure activity. Finally, adjunctive use of remifentanil did not prolong recovery times or increase post-ECT side effects. IMPLICATIONS: Remifentanil (100 microg IV) attenuated the acute hemodynamic response after electroconvulsive therapy (ECT) without adversely affecting the length of the ECT-induced seizure activity or prolonging recovery times.