Postanesthesia Recovery Scores Research Articles

Use of a Combination Lavender/Peppermint Aromatherapy Patch During Port Catheter Placement Under Monitored Anesthesia Care Does Not Reduce Time to Discharge Readiness: A Randomized Controlled Trial.

Background: Intraoperative anxiety is a common problem when Monitored Anesthesia Care (MAC) is used instead of general anesthesia during minor surgical procedures such as port catheter placement. Nonpharmacological anxiolytics such as aromatherapy have been studied for their effects on preoperative anxiety, but no placebo-controlled study of aromatherapy during surgeries under MAC has yet been performed. Methods: After IRB approval, 70 patients were randomized 1:1 to receive either a lavender/peppermint aromatherapy patch (Elequil Aromatabs®; Beekley Corporation) or a matching placebo patch. The primary outcome, time to readiness for discharge from postoperative acute care units (PACU; min), was assessed every 15 min until a modified postanesthesia recovery score for ambulatory patients (PARSAP) score of 18 or higher was reached. In the preoperative holding area, the assigned patch/placebo was activated and affixed to a folded towel placed aside the subject's head, contralateral to the side of the planned surgery. The towel and patch/placebo were discarded when the subject left the operating room (OR). Results: No difference was found between the treatment and placebo groups on the primary outcome of time to discharge readiness (mean [standard deviation, SD]: 82 [15] vs. 89 [21] min, respectively, p = 0.131). No difference was found between the treatment and placebo groups on the secondary outcomes of intraoperative midazolam dose, intraoperative opioid dose, intraoperative ondansetron dose, or intraoperative promethazine dose. No difference was found between the treatment and placebo groups in the proportion of subjects requiring rescue postoperative nausea and vomiting (PONV) medication in the PACU or the proportion of subjects requiring opioids in the PACU. No difference was found between the treatment and placebo groups in pain intensity in PACU, average PONV score in PACU, or patient satisfaction in PACU. PACU patient satisfaction was high for both the patch and placebo groups (35/35 [100%] vs. 32/34 [94%] "very satisfied," p = 0.239). Conclusions: Aromatherapy treatment is not indicated intraoperatively to reduce anxiety or the use of antiemetics in patients requiring Port catheter placement. Trial registration: Clinicaltrials.gov, identifier: NCT05328973.

Comparison of balanced anesthesia in spine surgery with dexmedetomidine added to sevoflurane and dexmedetomidine added to desflurane on recovery profile

Background: Spine surgery is challenging to anesthesiologist due to various factors. It is important to provide intraoperative hemodynamic stability, clear surgical field and a conscious, and pain free comfortable patient post-operative. Sevoflurane and desflurane provide rapid recovery. Dexmedetomidine provides sedation, stable, hemodynamics and analgesia. Dexmedetomidine has become an integral part of balanced anesthesia along with inhalational anesthetics in spine surgery. Aims and Objectives: Our study was done to compare recovery profile of sevoflurane and desflurane with dexmedetomidine and compare total dose of dexmedetomidine required in both the groups. Materials and Methods: Sixty ASA I-II patients undergoing spine surgery were randomly divided into two groups: Group A – Sevoflurane + Dexmedetomidine and Group B – Desflurane + Dexmedetomidine. Postoperatively, time to eye opening and extubation time was measured. The patient was shifted to post-anesthesia care unit (PACU) 10 min after extubation. Fast-track criteria (FTC) score was assessed for 1 h post-extubation in PACU. Results: Mean time to eye opening in Group A: 13.07±2.08 min which was significantly longer than in Group B: 9.17±2.23 min (P<0.05). Similarly, mean extubation time was shorter in Group B than in Group A, 12.77±2.50 min versus 17.83±2.68 min, respectively (P<0.05). FTC score was significantly higher in Group B as compared to Group A at all times (P<0.05), except at 60 min, when it was similar (P=1.000). Discharge criteria from PACU in all patients were achieved at 15 min in Group B, while in Group A, it was achieved at 30 min. Conclusion: We found that desflurane and dexmedetomidine combination is superior to sevoflurane and dexmedetomidine in time to eye opening and extubation time. Higher post-anesthesia recovery score (FTC score) is seen in desflurane/dexmedetomidine group than sevoflurane/dexmedetomidine group.

Total intravenous anesthesia induced and maintained by a combination of remimazolam and remifentanil without a neuromuscular blocking agent: a prospective, observational pilot study

BackgroundA novel short-acting benzodiazepine, Remimazolam, has recently been approved for general anesthesia and sedation. Hence, we investigated the feasibility and safety of remimazolam during the induction and maintenance of general anesthesia without using a neuromuscular blocking agent (NMBA) in patients undergoing hysteroscopic surgery.MethodsThis prospective observational study included 38 patients undergoing hysteroscopic surgery. Remimazolam and remifentanil were the main anesthetic agents without an NMBA, and a supraglottic airway was inserted to protect the airway. The induction time, amount of each anesthetic agent used during anesthesia, intraoperative bispectral index (BIS) hemodynamic parameters, and recovery profiles were measured.ResultsGeneral anesthesia was successfully administered to 37 patients using remimazolam and remifentanil without NMBA. The induction doses of remimazolam and remifentanil were 0.4 mg/kg (interquartile range [IQR] 0.34–0.47 mg/kg) and 1.07 μg/kg (IQR, 0.90–1.29 μg/kg), respectively. Additionally, the maintenance doses of remimazolam and remifentanil were 1.14 mg/kg/h (IQR, 0.88–1.55 mg/kg/h) and 0.06 μg/kg/min (IQR, 0.04–0.08 μg/kg/min), respectively. Intraoperative BIS values had risen temporarily > 60 in eight patients (21.6%) despite administration of 2 mg/kg/h of remimazolam; thus, they were treated with supplementary midazolam. The median recovery time was 7 min (IQR, 5–8 min) after 40 min (IQR, 40.0–57.5 min) of total mean anesthesia time. There was no correlation between the infusion dose of remimazolam and recovery profiles, such as recovery time, final BIS of anesthesia, modified observer assessment of alertness/sedation (OAA/S) scale or post-anesthesia recovery (PAR) score when arriving at the PACU, and length of stay in the PACU (all P > 0.05).ConclusionRemimazolam can be combined with remifentanil without an NMBA in female patients who undergo hysteroscopic surgery, during which a supraglottic airway is a feasible method to protect the airway.Trial registrationThe study protocol was registered at ClinicalTrials.gov (NCT05025410) on 27/08/2021.

Addition of dexmedetomidine and nalbuphine as an adjuvant to ketofol for deep sedation during endoscopic retrograde cholangiopancreatography: A prospective, randomized, double-blind study

Background: Deep sedation has evolved as a better choice against general anesthesia in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP). This study was aimed to evaluate the efficacy of dexmedetomidine and nalbuphine as an adjuvant to ketofol based deep sedation in ERCP.Methods: One hundred patients undergoing ERCP were randomly assigned to receive either IV dexmedetomidine 1 μg/kg (Group D, n = 50) or I. V nalbuphine 0.1 μg/kg (Group N, n = 50), 10 min before ketofol induction. The primary outcome was the total dose of ketofol used for induction and maintenance of deep sedation throughout the procedure. Hemodynamics and respiratory parameters, recovery characteristics, endoscopist's, and anesthetist satisfaction scores were secondary outcomes. P < 0.05 was considered statistically significant.Results: The dose of ketofol at the time of induction was significantly high in Group N as compared to Group D (P < 0.05). Supplemental dose of ketofol at the time of insertion of endoscope was equivalent in both the groups (P > 0.05) but significantly more number of patients in Group D (n = 19 vs. n = 11, P < 0.05) received supplement for facial pain score >5 compared to patients in Group N, where more patients received supplement for Ramsay Sedation Score <3 (n = 20 vs. n = 11 P < 0.05). Significant decrease in heart rate (HR) and mean arterial pressure from baseline values was found in Group D as compared to Group N (P < 0.001). Group N patients achieved postanesthesia recovery score >12 earlier than Group D (P < 0.001). Anesthetist satisfaction score was more in Group N (P < 0.05).Conclusion: Dexmedetomidine reduces the total consumption of ketofol and provides smooth hemodynamics whereas Nalbuphine provides better analgesia and early recovery with high anesthetist satisfaction for deep sedation in ERCP.

Common Pediatric PACU Problems

Perioperative care of neonates, infants, and children significantly differs from that in adults. It was estimated that about 1.5 million to 2 million children under 3 years of age undergo anesthesia annually in the United States. Although the exact incidence of pediatric postoperative problems and complications are not quantified, it is known that both minor and major morbidity most commonly occurs in infants and children under 3 years of age, especially those with severe comorbidities. In the ever-growing field of pediatric same-day surgery, safe and efficient flow through the perioperative and postoperative periods necessitates in-depth knowledge of managing potential PACU complications. In this chapter, we provide an overview of specific and most common pediatric complications such as airway complications, postoperative nausea and vomiting, and emergence agitation. Although not novel, availability of an immediate response team (designated postoperative anesthesia staff) and availability of PACU standing orders avoids delays in physician evaluation, treatment, and length of pediatric patients’ distress. We also lay out criteria for discharge, as well as implementation of Postanesthesia Recovery Score system evaluations. This review contains 3 figures, 11 tables, and 52 references. Keywords aspiration, bronchospasm, discharge criteria, emergence agitation, emergence delirium, laryngospasm, negative pressure pulmonary edema, PONV, postintubation croup, vomiting

Operative and anaesthetic factors influencing on delirium in the intensive care unit: An Analysis of electronic health records.

To analyse the operation, anaesthesia and recovery-related factors affecting the occurrence of delirium in the intensive care unit. The occurrence rate of postoperative delirium is high in surgical patients. Postoperative delirium most frequently occurs usually within 3days after an operation. This study used a secondary data analysis based on a case-control study. This study analysed data extracted from the electronic health records at a university hospital from October 2009-July 2015. One hundred and eighty patients with delirium admitted to the intensive care unit through the recovery room after surgery, and 720 nondelirium controls were included. A total of 17 variables were selected, and hierarchical logistic regression was performed to identify operative and anaesthetic factors influencing on delirium. STROBE statement was applied for reporting this study. The operation, anaesthesia and recovery-related factors increasing the risk of delirium included Class II or higher in the classification system of American Society of Anesthesiologists physical status, continuous remifentanil infusion and lower than seven-point postanaesthesia recovery score at the time of admission to the recovery room. The operative and anaesthetic factors influencing the occurrence of delirium should be assessed when a patient is admitted to the ICU following an operation even if a patient is conscious. Identifying operative and anaesthetic risk factors for delirium can improve the prevention intervention and the patient outcome in the intensive care unit.

Comparative Study of Oral Midazolam Syrup and Intranasal Midazolam Spray for Sedative Premedication in Pediatric Surgeries.

Introduction:Midazolam is a water-soluble benzodiazepine which is frequently administered by intravenous and oral routes. Its nasal spray has become recently available.Materials and Methods:In this study, after obtaining clearance from the ethical committe, 66 patients between the age group of 4 and 10 years comparable in demographic variables were randomly allocated into two groups of 33 each. Group “O” received oral midazolam (0.5 mg/kg) 20 min before induction. Group “N” received intranasal midazolam (0.2 mg/kg) 20 min before induction. The heart rate and blood pressure (systolic, diastolic, and mean) and oxygen saturation (SPO2) were recorded.Statistical Analysis Used:The statistical analysis was done using SPSS (Statistical Package for the Social Sciences) version 15.0 software. The values were represented in number (%) and mean±sd.Results:Satisfactory sedation scores were better in nasal spray group than oral group. Satisfactory ease of induction scores, recovery times, and postanesthesia recovery scores were better in the nasal spray group than in the oral group.Conclusion:Nasal midazolam spray is acceptable and is a good alternative to oral midazolam as premedication in the pediatric population.

Evaluation of effect of entropy monitoring on isoflurane consumption and recovery from anesthesia.

Background and Aims:Entropy monitoring entails measurement of the effect of anesthetic on its target organ rather than merely the concentration of anesthetic in the brain (indicated by alveolar concentration based on which minimum alveolar concentration [MAC] is displayed). We proposed this prospective randomised study to evaluate the effect of entropy monitoring on isoflurane consumption and anesthesia recovery period.Material and Methods:Sixty patients undergoing total abdominal hysterectomy under general anesthesia using an endotracheal tube were enrolled in either clinical practice (CP) or entropy (E) group. In group CP, isoflurane was titrated as per clinical parameters and MAC values, while in Group E, it was titrated to entropy values between 40 and 60. Data including demographics, vital parameters, alveolar isoflurane concentration, MAC values, entropy values, and recovery profile were recorded in both groups.Results:Demographic data and duration of surgery were comparable. Time to eye opening on command and time to extubation (mean ± standard deviation) were significantly shorter, in Group E (6.6 ± 3.66 and 7.27 ± 4.059 min) as compared to Group CP (9.77 ± 5.88 and 11.63 ± 6.90 min), respectively. Mean isoflurane consumption (ml/h) was 10.81 ± 2.08 in Group E and 11.45 ± 2.24 in Group CP and was not significantly different between the groups. Time to readiness to recovery room discharge and postanesthesia recovery scores were also same in both groups.Conclusion:Use of entropy monitoring does not change the amount of isoflurane consumed during maintenance of anesthesia or result in clinically significant faster recovery.

Median effective concentration of remifentanil in target controlled infusion for smooth tracheal extubation during emergence from general anesthesia in elderly patients

Study objectiveTo determine the median effective concentration (EC50) of remifentanil during targeted-controlled infusion for smooth tracheal extubation during emergence from total intravenous anesthesia in elderly patients. DesignProspective, Dixon up-and-down method. SettingPostoperative emergence. PatientsTwenty-four American Society of Anesthesiologists grade I-II female elderly patients undergoing elective jaw cyst surgery. InterventionsThe EC50 of remifentanil for smooth emergence was calculated by the Dixon up-and-down method. MeasurementsThe EC50 and 95% confidence intervals were analyzed by probit analysis using logistic regression. Vital signs (mean arterial pressure, heart rate, oxygen saturation, and end-tidal carbon dioxide partial pressure), postanesthesia recovery score, visual analogue pain scale, and adverse effects were monitored. Mean arterial pressure and heart rate were compared between patients with smooth extubation vs those with failed smooth extubation. Main resultsThe Dixon up-and-down method showed that the EC50 of remifentanil for smooth tracheal extubation during emergency from anesthesia was 0.94 ng/mL in female elderly patients. The probit analysis showed that the EC50 of remifentanil was 0.99 ng/mL (95% confidence interval, 0.52-1.51 ng/mL). Heart rate and mean arterial pressure were significantly lower in patients with smooth extubation as compared with those with failed smooth extubation at 0 minute (at extubation) as well as 1 and 5 minutes after extubation (P< .05). ConclusionsTarget infusion of remifentanil at 0.94 ng/mL could effectively inhibit tracheal extubation–related cough response and cardiovascular responses in 50% of the female elderly patients without delaying recovery from anesthesia, which could ensure smooth tracheal extubation during emergence from anesthesia.

Oral gabapentin premedication for elderly patients undergoing intraocular surgery

AimsTo compare effects of gabapentin premedication with diazepam in patients undergoing cataract surgery.MethodsIn a randomised double-blind study, the effects of gabapentin premedication as a sedative, anxiolytic, analgesic and oculohypotensive agent...

The Use of Propofol as a Sedative Agent in Gastrointestinal Endoscopy: A Meta-Analysis

ObjectivesTo assess the efficacy and safety of propofol sedation for gastrointestinal endoscopy, we conducted a meta-analysis of randomized controlled trials (RCTs) comparing propofol with traditional sedative agents.MethodsRCTs comparing the effects of propofol and traditional sedative agents during gastrointestinal endoscopy were found on MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE. Cardiopulmonary complications (i.e., hypoxia, hypotension, arrhythmia, and apnea) and sedation profiles were assessed.ResultsTwenty-two original RCTs investigating a total of 1,798 patients, of whom 912 received propofol only and 886 received traditional sedative agents only, met the inclusion criteria. Propofol use was associated with shorter recovery (13 studies, 1,165 patients; WMD –19.75; 95% CI –27.65, 11.86) and discharge times (seven studies, 471 patients; WMD –29.48; 95% CI –44.13, –14.83), higher post-anesthesia recovery scores (four studies, 503 patients; WMD 2.03; 95% CI 1.59, 2.46), better sedation (nine studies, 592 patients; OR 4.78; 95% CI 2.56, 8.93), and greater patient cooperation (six studies, 709 patients; WMD 1.27; 95% CI 0.53, 2.02), as well as more local pain on injection (six studies, 547 patients; OR 10.19; 95% CI 3.93, 26.39). Effects of propofol on cardiopulmonary complications, procedure duration, amnesia, pain during endoscopy, and patient satisfaction were not found to be significantly different from those of traditional sedative agents.ConclusionsPropofol is safe and effective for gastrointestinal endoscopy procedures and is associated with shorter recovery and discharge periods, higher post-anesthesia recovery scores, better sedation, and greater patient cooperation than traditional sedation, without an increase in cardiopulmonary complications. Care should be taken when extrapolating our results to specific practice settings and high-risk patient subgroups.

Premedication with midazolam nasal spray: an alternative to oral midazolam in children.

Background:Midazolam is a water soluble benzodiazepine which is frequently administered by intravenous and oral routes in our institution. Its nasal spray has become recently available.Objectives:To compare the efficacy of midazolam administered orally and by intranasal spray, with the specific objective of assessing their efficacy in terms of acceptability to the patients, whether they achieve a satisfactory sedation score, and the overall ease of inducing general anesthesia.Patients and Methods:Sixty healthy children of ASA grade I or II, aged 2–6 years who were undergoing elective surgery of approximately 30 minutes duration, were assigned to receive midazolam premedication in a randomized controlled trial. They were divided into 2 groups of 30 patients each. Group I: 30 patients received midazolam orally (parenteral solution mixed in honey). Group II: 30 patients received a commercially available midazolam nasal spray.Results:The study shows that children better accepted the drug when administered orally than when administered intranasally, although satisfactory sedation scores at 10 and 20 minutes were better in the nasal spray group than in the oral group [i.e., 6 (20%) vs. 0 (0%) at 10 min and 16 (53.3%) vs. 13 (43.3%), respectively]. Satisfactory ease of induction scores [24 (80%) vs. 13 (43.3%)], recovery times [11.63 ± 4.19 minutes vs. 25.20 ± 9.36 minutes], and post-anesthesia recovery scores were better in the nasal spray group (group II) than in the oral group (group I).Conclusions:On the basis of our study, we conclude that nasal midazolam spray is acceptable and is a good alternative to oral midazolam as premedication in the pediatric population.

Surgical Outcome Following Hip Fracture in Patients &amp;gt; 100 Years Old: Will They Ever Walk Again?

Introduction: Advances in medicine have led to a growth in the centenarian population (>100 years old). Centenarians are a largely unstudied population but as longevity increases, so will the cost of providing care for this group. Methods: One hundred and ten patients were admitted to SBMC 195 times between 2000 and 2009. Thirteen patients were treated for hip fracture. Data abstracted from the charts of these patients including age, gender, ethnicity, co-morbidities, advance directives (ADRs), functional status, length of stay (LOS), pre-operative and post-operative residential status and ambulatory status, ASA grade, type of anesthesia, duration of surgery and for complications of surgery or anesthesia. Results: The mean age was 101.2 years (100 to 104 years) with an M:F ratio of 2:11. The most common co-morbidities were hypertension, anemia, congestive heart failure (CHF) and coronary artery disease. Among the 13 patients with hip fractures, 12 had operative intervention while one was treated conservatively. The mean ASA grade was 2.75 (1 - 4). Five patients had surgery under general anesthesia and seven received spinal anesthesia. Five patients received a bi-polar hip replacement and seven patients underwent internal fixation. The mean operative time was 47.6 min (27 - 90 min). Five (41.7%) patients required a peri-operative blood transfusion. The mean post-anesthesia recovery score was 9.42 (9 - 10). All patients, except two, were returned to their pre-operative ambulatory status. Advanced directives were held by only 30.8% of patients on admission. There were 2 post-operative morbidities and 1 mortality. Conclusions: Centenarians represent a high-risk-surgical population due to their age and associated comorbidities. Hip fracture is the cause of >10% of all admissions and accounts for 29% of all surgical procedures in this age group. Despite their age and comorbidities, surgery for hip fracture is well tolerated and nearly all patients were returned to their pre-hospital ambulatory status. Education on advanced directives is lacking.

Comparison of Ketamine and Fentanyl for Postoperative Pain Relief in Children Following Adenotonsillectomy

Adenotonsillectomy has a high incidence of postoperative pain. Therefore, the purpose of this study was to evaluate the effectiveness and safety of either ketamine or fentanyl for postoperative pain relief in children following adenotonsillectomy. Sixty children aged 3-12 years, scheduled for adenotonsillectomy, were enrolled in this randomized, double-blind study. Patients were divided into two groups of 30 cases and received intravenous ketamine (0.5 mg kg(-1)) or fentanyl (1 microg kg(-1)). Modified Hannallah pain scale or Observational Pain Scores (OPS), nausea, vomiting, bleeding, rescue analgesia, sedation and post-anesthesia recovery scores were recorded both at first and 15th minute postoperatively. Moreover, patients receiving ketamine (group 1) or fentanyl (group 2) had comparable OPS and sedation score both on arrival and at 15th minute in the recovery room (p > 0.05). Although rescue analgesics were similarly required in both groups (p > 0.05), the time to reach rescue analgesia was shorter in group 1 (p = 0.001). Only one patient in fentanyl group had nausea and vomiting in the first 15 min that needed antiemetic in the recovery room. In conclusion, intravenous fentanyl (1 microg kg(-1)) compared with intravenous ketamine (0.5 mg kg(-1)) might provide extended time to first analgesic in children undergoing adenotonsillectomy. Interestingly, fentanyl and ketamine did not differ in post-operative vomiting.

Premedication With Midazolam Nasal Spray: An Alternative to Oral Midazolam in Children

Background: Midazolam is a water soluble benzodiazepine which is frequently administered by intravenous and oral routes in our institution. Its nasal spray has become recently available. Objectives: To compare the efficacy of midazolam administered orally and by intranasal spray, with the specific objective of assessing their efficacy in terms of acceptability to the patients, whether they achieve a satisfactory sedation score, and the overall ease of inducing general anesthesia. Patients and Methods: Sixty healthy children of ASA grade I or II, aged 2–6 years who were undergoing elective surgery of approximately 30 minutes duration, were assigned to receive midazolam premedication in a randomized controlled trial. They were divided into 2 groups of 30 patients each. Group I: 30 patients received midazolam orally (parenteral solution mixed in honey). Group II: 30 patients received a commercially available midazolam nasal spray. Results: The study shows that children better accepted the drug when administered orally than when administered intranasally, although satisfactory sedation scores at 10 and 20 minutes were better in the nasal spray group than in the oral group [i.e., 6 (20%) vs. 0 (0%) at 10 min and 16 (53.3%) vs. 13 (43.3%), respectively]. Satisfactory ease of induction scores [24 (80%) vs. 13 (43.3%)], recovery times [11.63 ± 4.19 minutes vs. 25.20 ± 9.36 minutes], and post-anesthesia recovery scores were better in the nasal spray group (group II) than in the oral group (group I). Conclusions: On the basis of our study, we conclude that nasal midazolam spray is acceptable and is a good alternative to oral midazolam as premedication in the pediatric population.

The effect of flunarizine pretreatment on postoperative morphine consumption

This study was designed to document the effects 10 mg flunarizine, administrated in the preoperative period, on postoperative morphine requirement and analgesic quality, in abdominal surgery. Thirty patients, aged 18 to 55 years, were studied. Patients were randomly allocated to one of two equally sized groups, and received either 2 capsules of 5 mg flunarizine (Group I) or 2 placebo capsules (Group II) 2 hours before the operation, immediately after the extubation and at the 15th minute, Aldrete postanesthesia recovery scores were assessed. In the postoperative period, patients were connected to a patient-controlled analgesia device for intravenous morphine, and the first analgesic requirement time was recorded. Ramsay sedation scale, visual analogue pain scale and morphine consumption were assessed after the extubation. Systolic arterial pressures at the 5th minute of the preoperative period were significantly lower in the flunarizine group than placebo group. Heart rates in the 45th minute were also lower in the flunarizine group. Flunarizine patients reported statistically lower visual analogue pain scale values in the postoperative 12th hour. There was no significant difference in postoperative sedation scores between the groups. Flunarizine did not lengthen the first analgesic requirement time and similarly did not lessen the morphine requirement. We conclude that 10 mg flunarizine administered in the preoperative period had no significant effects on clinical parameters, had no analgesic effect and did not augment the analgesic effects of morphine at this dose.

Effects of pre- versus post-anaesthetic buprenorphine on propofol-anaesthetized rats

ObjectiveTo compare the effect of pre- versus post-anaesthetic intramuscular (IM) buprenorphine on intermittent intravenous (IV) propofol anaesthesia in rats. AnimalsTwenty healthy, adult, female, ex-breeder Sprague–Dawley rats within the mass range 274–379 g. Materials and methodsAnimals were randomly allocated to one of two groups. Group 1 (n = 10) received 9 μg buprenorphine (IM) at the start and group 2 (n = 10) received the same dose buprenorphine at the end of anaesthesia. Five animals from each group (randomly selected) received a standardized 40-minute surgical procedure (procedure 1), the remaining half, a standardized 60-minute surgical procedure (procedure 2). Induction of anaesthesia with 4% isoflurane carried in oxygen was immediately followed by IV propofol (3 mg) and intraperitoneal diazepam (500 μg). Anaesthesia was maintained using periodic IV propofol (500 μg) injected through an indwelling tail vein cannula, by an operator ignorant of the buprenorphine status. One hour after recovery from anaesthesia, the animals’ level of awareness were scored by an observer ignorant of both the buprenorphine status and the total propofol dose administered. ResultsBuprenorphine administration at the start of anaesthesia versus administration at the end resulted in a significant reduction in the total per-kilogram requirement for propofol from a mean of 24 mg kg−1 (±2.5 mg kg−1, n = 5) to 5.5 mg kg−1 (±1.1 mg kg−1, n = 5) for procedure 1, and from a mean of 30 mg kg−1 (±1.2 mg−1, n = 5) to 16 mg kg−1 (±1.0 mg kg−1, n = 5) in procedure 2. Animals receiving buprenorphine at the start of anaesthesia demonstrated a higher level of awareness 1 hour after cessation of anaesthesia. No adverse effects were evident in either group 24 hours after recovery. ConclusionsBuprenorphine administration at the start of periodic IV propofol anaesthesia in rats resulted in a significant reduction in the total propofol requirement and significantly improved the 1-hour post-anaesthesia recovery score. Clinical relevanceBesides the ethical advantage of pre-emptive analgesia, pre-anaesthetic medication with buprenorphine in rats significantly reduces the total propofol requirements for surgical anaesthesia and in this study was found to be a safe and effective method of anaesthesia.

The effect of hypotensive anaesthesia on cognitive functions and recovery at endoscopic sinus surgery

The effect of hypotensive anaesthesia on cognitive functions and recovery at endoscopic sinus surgery

The Effect of Intravenous Ketamine on Recovery from Total Intravenous Anesthesia with Propofol

Background: This study was designed to evaluate the effects of the continuous infusion of ketamine on the cardiovascular system, patient recovery, and the postoperative analgesic effect of total intravenous anesthesia (TIVA) with propofol. Methods: Forty-one patients undergoing tympanoplasty were randomly allocated to a control (no ketamine, n = 12), or to K1 (ketamine 0.1/ml, n = 16) or K2 groups (ketamine 0.2/ml, n = 13). Ketamine and propofol were continuously administerd by target controlled infusion (TCI) at different ketamine steady-state concentrations. The severity of injection pain was assessed and hemodynamic responses were measured before and after intubation and skin incision, respectively. Respective times lapsed from the discontinuation of propofol to eye opening, hand grasp, and extubation were measured, and the concentration of propofol and ketamine were determined at the time of extubation. Visual analogue scale (VAS) for postoperative pain, postanesthesia recovery score (PARS) and post-operative complications were also evaluated in the recovery room. Results: No statistical differences were identified with respect to severity of injection pain, hemodynamic response, VAS or PARS among the groups. But the respective times lapsed to extubation, eye opening and hand grasp after the discontinuation of propofol were longer in group K2 than in the other groups (P /ml, 0.2/ml) appeared inadequate to maintain hemodynamic stability and the postoperative analgesic effect, and to prevent delayed emergence.

Electroencephalogram monitoring facilitates sedation with propofol for routine ERCP: A randomized, controlled trial

Background: Endoscopy with the patient under sedation with propofol requires careful monitoring of patient consciousness and vital signs to achieve the desired hypnotic effect without overdosage. Because level of consciousness is difficult to judge by clinical observation alone, electroencephalogram monitoring has been used to guide general anesthesia. Methods: Eighty consecutive patients (mean [SD] age 62 [14] years) undergoing ERCP for various indications were randomly allocated to 2 groups. In group A (n = 40), propofol sedation was guided by conventional monitoring (heart rate, blood pressure, oxygen saturation, electrocardiogram), whereas electroencephalogram monitoring was performed but not displayed to the physician who administered the drug. In group B (n = 40), electroencephalogram monitoring was displayed online and used to guide propofol administration to maintain a preselected sedation level. Procedure-related parameters, recovery time, and quality (postanesthesia recovery score), as well as patient cooperation and tolerance for the procedure (visual analog scale) were prospectively assessed. Results: The groups were comparable with regard to demographic, clinical, and procedure-related parameters. Mean propofol dose was significantly lower in group B than in group A (respectively, 290 [158] mg vs. 374 [166] mg; p = 0.02). The mean decrease in arterial blood pressure was significantly lower in group B than in group A (respectively, 11 [6] mm Hg vs. 14 [7] mm Hg; p < 0.05). Clinically relevant changes in vital signs to below critical values were observed in both groups, albeit infrequently. Efficacy of sedation was also rated similar in both groups, whereas mean recovery time was significantly faster in group B than in group A (respectively, 16 [7] minutes vs. 20 [8] minutes; p = 0.02). Accordingly, the recovery score tended to be better in group B compared with group A (respectively, 8.4 [1.0] points vs. 8.0 [0.9] points; p = 0.06). The predefined target level of sedation was maintained during 75% of the procedure time in group B but in only 58% of the time in group A ( p < 0.05), and deeper sedation levels were achieved significantly more often in group B patients compared with group A patients ( p < 0.05). Conclusion: Electroencephalogram monitoring enables more effective titration of propofol dosage for sedation during endoscopy and is, therefore, associated with faster patient recovery. (Gastrointest Endosc 2002;56:817-24.)