Recovery characteristics using isoflurane or propofol for maintenance of anaesthesia: a double-blind controlled trial

[The effects of memantine on recovery, cognitive functions, and pain after propofol anesthesia]

OBJECTIVES

Postoperative cognitive dysfunction refers to the problems associated with thought and memory that are often experienced after major surgery. The aim of this study is to evaluate the effects of intraperitoneally administered memantine on recovery, cognitive functions, and pain after propofol anesthesia.

METHODS

The study was conducted in Gazi University Animal Research Laboratory, Ankara, Turkey in January 2012. Twenty-four adult female Wistar Albino rats weighing 170-270g were educated for 300s in the radial arm maze (RAM) over three days. Group P was administered 150mgkg(-1) of intraperitoneal (IP) propofol; Group M was given 1mgkg(-1) of IP memantine; and Group MP was given 1mgkg(-1) of IP memantine before being administered 150mgkg(-1) of IP propofol. The control group received only IP saline. RAM and hot plate values were obtained after recovery from the groups that received propofol anesthesia and 30min after the administration of drugs in other two groups.

RESULTS

The duration of recovery for Group MP was significantly shorter than Group P (p<0.001), and the number of entries and exits in the RAM by Group MP was significantly higher during the first hour when compared to Group P (p<0.0001). Hot plate values, on the other hand, were found to be significantly increased in all groups when compared to the control values, aside from Group C (p<0.0001).

CONCLUSION

In this study, memantine provided shorter recovery times, better cognitive functions, and reduced postoperative pain. From this study, we find that memantine has beneficial effects on recovery, cognitive functions, and pain after propofol anesthesia.

Effects of Sevoflurane, Isoflurane and Propofol Infusions on Post-Operative Recovery Criteria in Geriatric Patients

We compared the effects of sevoflurane, isoflurane and propofol infusions on postoperative recovery criteria in geriatric patients. Sixty patients aged > 65 years, classified as American Society of Anesthesiologists (ASA) group 1 or 2 and undergoing gynaecological or urological procedures were randomized equally into three groups. Group 1 received 1 minimum alveolar concentration (MAC) sevoflurane in a 50% O2/N2O mixture and group 2 received 1 MAC isoflurane in a 50% O2/N2O mixture. Group 3 received a 50% O2/N2O mixture plus propofol total intravenous anaesthesia (8 mg/kg for the first 30 min, followed by 6 mg/kg for maintenance). Recovery criteria comprising the times to spontaneous eye opening, extubation, response to verbal stimuli and orientation were recorded following the discontinuation of anaesthesia. Recovery times were significantly shorter in groups 1 and 3 compared with group 2. We conclude that sevoflurane and propofol had similar effects on recovery criteria and were associated with a faster recovery than isoflurane.

The effects of memantine on recovery, cognitive functions, and pain after propofol anesthesia

OBJECTIVES

Postoperative cognitive dysfunction refers to the problems associated with thought and memory that are often experienced after major surgery. The aim of this study is to evaluate the effects of intraperitoneally administered memantine on recovery, cognitive functions, and pain after propofol anesthesia.

METHODS

The study was conducted in Gazi University Animal Research Laboratory, Ankara, Turkey in January 2012. Twenty-four adult female Wistar Albino rats weighing 170-270g were educated for 300s in the radial arm maze (RAM) over three days. Group P was administered 150mgkg(-1) of intraperitoneal (IP) propofol; Group M was given 1mgkg(-1) of IP memantine; and Group MP was given 1mgkg(-1) of IP memantine before being administered 150mgkg(-1) of IP propofol. The control group received only IP saline. RAM and hot plate values were obtained after recovery from the groups that received propofol anesthesia and 30min after the administration of drugs in other two groups.

RESULTS

The duration of recovery for Group MP was significantly shorter than Group P (p<0.001), and the number of entries and exits in the RAM by Group MP was significantly higher during the first hour when compared to Group P (p<0.0001). Hot plate values, on the other hand, were found to be significantly increased in all groups when compared to the control values, aside from Group C (p<0.0001).

CONCLUSION

In this study, memantine provided shorter recovery times, better cognitive functions, and reduced postoperative pain. From this study, we find that memantine has beneficial effects on recovery, cognitive functions, and pain after propofol anesthesia.

Post-Operative Nausea and Vomiting (PONV) after Thyroid Surgery: A Prospective, Randomized Study Comparing Totally Intravenous versus Inhalational Anesthetics

The incidence of postoperative nausea and vomiting (PONV) after thyroidectomy and the association of Propofol versus Sevoflurane use for anesthesia maintenance were investigated during a randomized, prospective study. One hundred and ninety-eight patients underwent thyroidectomy receiving either Sevoflurane (0.5-1.3% end-tidal) or Propofol (50-200 mg/kg/min) for anesthesia maintenance. All patients received Propofol for induction of anesthesia, Succinylcholine or Vecuronium, Nitrous Oxide, and Fentanyl. Prophylactic antiemetics were not administered. The combined incidence of PONV was 54.4 per cent over the 24-hour postoperative evaluation period. PONV was more common in patients receiving Sevoflurane than Propofol for maintenance of anesthesia (64.6% vs 43.8%). In women (n = 117), the incidence of PONV resulted higher when receiving inhalational Sevoflurane than Propofol for maintenance (70.6% vs 42.4%). However, in men (n = 81), there was no significant difference in PONV between anesthetic regimens (47.4% with Sevoflurane vs 49.6% with Propofol). Patients undergoing thyroid surgery are at high risk for the development of PONV. Propofol for maintenance of anesthesia, although more expensive than Sevoflurane, may reduce the rate of PONV.

The mu-opioid receptor agonist remifentanil induces acute dysphoria irrespective of its analgesic properties

Mu-opioidergic agonists are believed to induce euphoria, whereas kappa-agonists are thought to lead to dysphoria. Our study investigated mood effects of remifentanil, a mu-receptor opioid agonist, in healthy male volunteers. Moreover, we examined interactions between mood and pain. Three conditions were investigated in 21 volunteers: saline, 0.05 and 0.15 microg kg(-1) min(- 1) remifentanil. Each condition was investigated during non-painful heat and during painful heat stimulation. Mood was measured with the von Zerssen's mood scale (Bf-S score) and pain intensity using a Visual Analogue Scale (VAS). High Bf-S scores are reflecting discontent and dysphoria. Changes were tested for significance using a linear mixed model approach. Remifentanil significantly increased Bf-S scores during painful heat (+91.4%), indicating a negative mood effect, although it reduced VAS scores of painful heat intensity (-49.0%). The type of sensory stimulation (non-painful versus painful) had no effect on mood. There was no interaction between remifentanil dose and type of stimulation. Our results provide evidence for negative mood effects of remifentanil. These effects occur with and without pain. Taken into account that remifentanil reduces pain, one could have expected analgesia-related amelioration of mood instead. In clinical practice, these remifentanil effects should be considered and a comedication might be advisable.

Effects of spinal anesthesia and laryngeal mask anesthesia on mood states during hemorrhoidectomy

The present study was undertaken to compare the effects of laryngeal mask anesthesia (LMA) and spinal anesthesia on mood states in patients undergoing hemorrhoidectomy. A total of 46 patients who underwent hemorrhoidectomy for grade III and IV hemorrhoids were included in this study. LMA with fentanyl plus propofol was given to 23 patients, and spinal anesthesia with bupivacaine was administered to 23 patients. Mood changes were assessed preoperatively and 2 h postoperatively with the Profile of Mood States (POMS), which consists of 65 questions that are designed to measure 6 identifiable mood states (tension, depression, anger, vigor, fatigue, and confusion). No significant differences were noted between the 2 groups in terms of baseline POMS global and subscale scores, except for scores regarding vigor. No significant mood changes were observed after hemorrhoidectomy in patients who were given LMA; however, an increase in total POMS score was reported in patients given spinal anesthesia. These findings suggest that mood score is affected by spinal anesthesia but not by LMA in patients who are about to undergo hemorrhoidectomy.

Comparison of recovery profile after ambulatory anesthesia with propofol, isoflurane, sevoflurane and desflurane: a systematic review

In this systematic review we focused on postoperative recovery and complications using four different anesthetic techniques. The database MEDLINE was searched via PubMed (1966 to June 2002) using the search words "anesthesia" and with ambulatory surgical procedures limited to randomized controlled trials in adults (>19 yr), in the English language, and in humans. A second search strategy was used combining two of the words "propofol," "isoflurane," "sevoflurane," or "desflurane". Screening and data extraction produced 58 articles that were included in the final meta-analysis. No differences were found between propofol and isoflurane in early recovery. However, early recovery was faster with desflurane compared with propofol and isoflurane and with sevoflurane compared with isoflurane. A minor difference was found in home readiness between sevoflurane and isoflurane (5 min) but not among the other anesthetics. Nausea, vomiting, headache, and postdischarge nausea and vomiting incidence were in favor of propofol compared with isoflurane (P < 0.05). A larger number of patients in the inhaled anesthesia groups required antiemetics compared with the propofol group. We conclude that the differences in early recovery times among the different anesthetics were small and in favor of the inhaled anesthetics. The incidence of side effects, specifically postoperative nausea and vomiting, was less frequent with propofol.

IMPLICATIONS

A systematic analysis of the literature comparing postoperative recovery after propofol, isoflurane, desflurane, and sevoflurane-based anesthesia in adults demonstrated that early recovery was faster in the desflurane and sevoflurane groups. The incidence of nausea and vomiting were less frequent with propofol.

Cricoid yoke: the effect of surface area and applied force on discomfort experienced by conscious volunteers

BACKGROUND AND OBJECTIVE

The application of cricoid force is central to techniques that reduce the risk of gastric regurgitation and the subsequent pulmonary aspiration associated with obstetric and emergency anaesthesia. The discomfort associated with cricoid force in awake preoperative patients increases the incidence of coughing, struggling and pain during induction of anaesthesia. This study determined if increasing the surface area of a cricoid yoke reduced the associated discomfort in volunteers.

METHODS

Fifty volunteers participated in a randomized single-blinded study. The cricoid yoke was positioned using standard anatomical landmarks and forces of 10, 20, 30 and 40 N were applied in a random order for 20s, using two different yoke attachments with surface areas of 3 and 10 cm2. A rest of 30s was allowed between the application of forces. Discomfort was graded by volunteers on a scale from 0 to 10 (0: no discomfort; 10: worse discomfort imaginable). A score of 10 was allocated if the volunteers could not tolerate the applied force for 20s.

RESULTS

Median scores for the small yoke were always higher than those for the large yoke at each force. There were significant differences between the scores for the small and large yokes at 10 and 20 N (P < 0.001) and 30 N (P = 0.0233), but there was no significant difference at 40 N.

CONCLUSIONS

The larger yoke was tolerated better by volunteers when clinically relevant cricoid forces were applied.

Tracheal intubation without muscle relaxants: remifentanil or alfentanil in combination with propofol

BACKGROUND AND OBJECTIVE

In some situations, the use of muscle relaxants (neuromuscular blocking drugs) are undesirable or contraindicated. We compared intubating conditions without muscle relaxants in premedicated patients receiving either alfentanil 40 microg kg(-1) or remifentanil 2, 3 or 4 microg kg(-1) followed by propofol 2 mg kg(-1).

METHODS

In a randomized, double-blind study, 80 healthy patients were assigned to one of four groups (n = 20). After intravenous atropine, alfentanil 40 microg kg(-1) or remifentanil 2, 3 or 4 microg kg(-1) were injected over 90 s followed by propofol 2 mg kg(-1). Ninety seconds after administration of the propofol, laryngoscopy and tracheal intubation were attempted. Intubating conditions were assessed as excellent, good or poor on the basis of ease of lung ventilation, jaw relaxation, laryngoscopy, position of the vocal cords, and patient response to intubation and slow inflation of the endotracheal tube cuff.

RESULTS

Seven patients who received remifentanil 2 microg kg(-1) and one patient who received remifentanil 3 microg kg(-1) could not be intubated at the first attempts. Excellent intubating conditions (jaw relaxed, vocal cords open and no movement in response to tracheal intubation and cuff inflation) were observed in those who received either alfentanil 40 microg kg(-1) (45% of patients) or remifentanil in doses of 2 microg kg(-1) (20%), 3 microg kg(-1) (75%) or 4 microg kg(-1) (95%). Overall, intubating conditions were significantly better (P < 0.05), and the number of patients showing excellent conditions were significantly higher (P < 0.05) in patients who received remifentanil 4 microg kg(-1) compared with those who received alfentanil 40 microg kg(-1) or remifentanil 2 microg kg(-1). No patient needed treatment for hypotension or bradycardia.

CONCLUSIONS

Remifentanil 4 microg kg(-1) and propofol 2 mg kg(-1) administered in sequence intravenously provided good or excellent conditions for tracheal intubation in all patients without the use of muscle relaxants.

Stability of the LMA-ProSeal and standard laryngeal mask airway in different head and neck positions: a randomized crossover study

BACKGROUND AND OBJECTIVE

The LMA-ProSeal laryngeal mask airway is a new laryngeal mask airway with a modified cuff and drainage tube. We compared oropharyngeal leak pressure, intracuff pressure and anatomical position (assessed fibreoptically) for the Size 5 LMA-ProSeal laryngeal mask airway and the classic laryngeal mask airway in different head-neck positions and using different intracuff inflation volumes.

METHODS

Thirty paralysed anaesthetized adult male patients were studied. The LMA-ProSeal laryngeal mask airway and the classic laryngeal mask airway were inserted into each patient in random order. The oropharyngeal leak pressure, intracuff pressure, and anatomical position of the airway tube and drainage tube (LMA-ProSeal laryngeal mask airway only) were documented in four head and neck positions (neutral first, then flexion, extension and rotation in random order), and at 0-40 mL cuff volumes in the neutral position in 10 mL increments.

RESULTS

Compared with the neutral position, the oropharyngeal leak pressure for both the LMA-ProSeal laryngeal mask airway and the classic laryngeal mask airway was higher in flexion and rotation (all P < or = 0.02), but lower in extension (all P < or = 0.01). Changes in head-neck position did not alter the anatomical position of the airway tube or the drainage tube. The oropharyngeal leak pressure was always higher for the LMA-ProSeal laryngeal mask airway (all P < or = 0.005) and anatomical position better for the classic laryngeal mask airway (all P < or = 0.04).

CONCLUSIONS

The anatomical position of the LMA-ProSeal and the classic laryngeal mask airway is stable in different head-neck positions, but head-neck flexion and rotation are associated with an increase, and head-neck extension a decrease, in oropharyngeal leak pressure and intracuff pressure. The Size 5 LMA-ProSeal laryngeal mask airway is capable of forming a more effective seal than the Size 5 classic laryngeal mask airway in males.

Breathing pattern and workload during automatic tube compensation, pressure support and T-piece trials in weaning patients

BACKGROUND AND OBJECTIVE

Automatic tube compensation has been designed as a new ventilatory mode to compensate for the non-linear resistance of the endotracheal tube. The study investigated the effects of automatic tube compensation compared with breathing through a T-piece or pressure support during a trial of spontaneous breathing used for weaning patients from mechanical ventilation of the lungs.

METHODS

Twelve patients were studied who were ready for weaning after prolonged mechanical ventilation (10.2 +/- 8.4 days) due to acute respiratory failure. Patients with chronic obstructive pulmonary disease were excluded. Thirty minutes of automatic tube compensation were compared with 30 min periods of 7 cmH2O pressure support and T-piece breathing. Breathing patterns and workload indices were measured at the end of each study period.

RESULTS

During T-piece breathing, the peak inspiratory flow rate (0.65 +/- 0.20 L s(-1)) and minute ventilation (8.9 +/- 2.7L min(-1)) were lower than during either pressure support (peak inspiratory flow rate 0.81 +/- 0.25 L s(-1) minute ventilation 10.2 +/- 2.3 L min(-1), respectively) or automatic tube compensation (peak inspiratory flow rate 0.75 +/- 0.26L s(-1); minute ventilation 10.8 +/- 2.7 L min(-1)). The pressure-time product as well as patients' work of breathing were comparable during automatic tube compensation (pressure-time product 214.5 +/- 104.6 cmH2O s(-1) min(-1), patient work of breathing 1.1 +/- 0.4 J L(-1)) and T-piece breathing (pressure-time product 208.3 +/- 121.6 cmH2O s(-1) min(-1), patient work of breathing 1.1 +/- 0.4 J L(-1)), whereas pressure support resulted in a significant decrease in workload indices (pressure-time product 121.2 +/- 64.1 cmH2O s(-1) min(-1), patient work of breathing 0.7 +/- 0.4 J L(-1)).

CONCLUSIONS

In weaning from mechanical lung ventilation, patients' work of breathing during spontaneous breathing trials is clearly reduced by the application of pressure support 7 cmH2O, whereas the workload during automatic tube compensation corresponded closely to the values during trials of breathing through a T-piece.

Anaesthetic agents in adult day case surgery

This study reports a review of all comparative published studies of adult day case anaesthesia in the English language up to December 2000. Ten databases were searched using appropriate keywords and data were extracted in a standardized fashion. One hundred-and-one published studies were examined. Recovery measurements were grouped as early, intermediate, late, psychomotor and adverse effects. With respect to induction of anaesthesia, propofol was superior to methohexital, etomidate and thiopental, but equal to sevoflurane and desflurane. Desflurane and sevoflurane were both superior to thiopental. There was no detectable difference between sevoflurane and isoflurane. With respect to the maintenance of anaesthesia, isoflurane and halothane were the worst. There were no significant differences between propofol, desflurane, sevoflurane and enflurane. Propofol is the induction agent of choice in day case patients. The use of a propofol infusion and avoidance of nitrous oxide may help to reduce postoperative nausea and vomiting.

Prediction of difficult tracheal intubation

BACKGROUND AND OBJECTIVE

Preoperative bedside screening tests for difficult tracheal intubation may be neither sensitive nor specific enough for clinical use. The aim was to investigate if a combination of the Mallampati classification of the oropharyngeal view with either the thyromental or sternomental distance measurement improved the predictive value.

METHODS

A total of 212 (109 male, 103 female) non-obstetric surgical patients, aged >18 yr, undergoing elective surgical procedures requiring tracheal intubation were assessed preoperatively with respect to the oropharyngeal (modified Mallampati) classification, thyromental and sternomental distances. An experienced anaesthetist, blinded to the preoperative airway assessment, performed laryngoscopy and graded the view according to Cormack and Lehane's classification.

RESULTS

Twenty tracheal intubations (9%) were difficult as defined by a Cormack and Lehane Grade 3 or 4, or the requirement for a bougie in patients with Cormack and Lehane Grade 2. Used alone, the Mallampati oropharyngeal view, and thyromental and sternomental distances were associated with poor sensitivity, specificity and positive predictive values. Combining the Mallampati Class III or IV with either a thyromental distance <6.5cm or a sternomental distance <12.5cm decreased the sensitivity (from 40 to 25 and 20%, respectively), but maintained a negative predictive value of 93%. The specificity and positive predictive values increased from 89 and 27% respectively for Mallampati alone to 100%.

CONCLUSIONS

The findings suggest that the Mallampati classification, in conjunction with measurement of the thyromental and sternomental distances, may be a useful routine screening test for preoperative prediction of difficult tracheal intubation.

Remifentanil versus alfentanil in total intravenous anaesthesia for day case surgery

BACKGROUND AND OBJECTIVE

We assessed the intraoperative haemodynamic responses and recovery profiles of total intravenous anaesthesia with remifentanil and alfentanil for outpatient surgery.

METHODS

Patients in Group 1 (n = 20) received alfentanil 20 microg kg(-1) followed by 2 microg kg(-1) min(-1) intravenously; patients in Group 2 (n = 20) received remifentanil 1 microg kg(-1) followed by 0.5 microg kg(-1) min(-1) intravenously. Both groups then received propofol 2 mg kg(-1) followed by 9 mg kg(-1) h(-1) intravenously. Five minutes after skin incision, infusion rates were decreased, and at the end of surgery, all infusions were discontinued. Early recovery was assessed by the Aldrete score, whereas intermediate recovery was assessed with the postanaesthetic discharge scoring system (PADS).

RESULTS

Perioperative arterial pressure was similar in both groups; heart rate was lower in Group 2 (P < 0.05). The times to spontaneous and adequate respiration, response to verbal commands, extubation and times for Aldrete score > or = 9 were shorter in Group 2 patients (P < 0.05). Pain scores were higher in Group 2 patients (P < 0.05). Overall times for postanaesthetic discharge scores > or = 9 were similar.

CONCLUSIONS

Early recovery of patients after day surgery is significantly shorter after total intravenous anaesthesia with remifentanil compared with that with alfentanil but postoperative pain management must be planned ahead.

Effects of different doses of oral ketamine for premedication of children

BACKGROUND AND OBJECTIVE

A need exists for a safe and effective oral preanaesthetic medication for use in children undergoing elective surgery. The study sought to define the dose of oral ketamine that would facilitate induction of anaesthesia without causing significant side-effects.

METHODS

We studied 80 children undergoing elective surgery under general anaesthesia who received oral ketamine 4, 6 or 8 mg kg(-1) in a prospective, randomized, double-blind placebo controlled study. We compared the reaction to separation from parents, transport to the operating room, the response to intravenous cannula insertion and application of an anaesthetic facemask, the induction of anaesthesia and recovery from anaesthesia.

RESULTS

In the group receiving ketamine 8 mg kg(-1), the children were significantly calmer than those of the other groups, and anaesthesia induction was more comfortable. Recovery from anaesthesia was longer in the group receiving ketamine 8 mg kg(-1) compared with the other groups, but no differences between the groups were observed after 2 h in the recovery room.

CONCLUSIONS

It is concluded that oral ketamine 8 mg kg(-1) is an effective oral premedication in inpatient children undergoing elective surgery.

Trendelenburg positioning after cardiac surgery: effects on intrathoracic blood volume index and cardiac performance

BACKGROUND AND OBJECTIVE

The efficacy of the Trendelenburg position, a common first step to treat suspected hypovolaemia, remains controversial. We evaluated its haemodynamic effects on cardiac preload and performance in patients after cardiac surgery.

METHODS

Twelve patients undergoing mechanical ventilation of the lungs who demonstrated left ventricular 'kissing papillary muscles' by transoesophageal echocardiography, thus suggesting hypovolaemia, were positioned 30 degrees head down for 15 min immediately after cardiac surgery. Cardiac output by thermodilution, central venous pressure, pulmonary artery occlusion pressure, left ventricular end-diastolic area by transoesophageal echocardiography and intrathoracic blood volume by thermo- and dye dilution were determined before, during and after this Trendelenburg manoeuvre.

RESULTS

Trendelenburg's manoeuvre was associated with increases in central venous pressure (9 +/- 2 to 12 +/- 3 mmHg) and pulmonary artery occlusion pressure (8 +/- 2 to 11 +/- 3 mmHg). The intrathoracic blood volume index increased slightly (dye dilution from 836 +/- 129 to 872 +/- 112 mL m(-2); thermodilution from 823 +/- 129 to 850 +/- 131 mL m(-2)) as did the left ventricular end-diastolic area index (7.5 +/- 2.1 to 8.1 +/- 1.7 cm2 m(-2)), whereas mean arterial pressure and the cardiac index did not change significantly. After supine repositioning, the cardiac index decreased significantly below baseline (3.0 +/- 0.6 versus 3.5 +/- 0.8 L min(-1) m(-2)) as did mean arterial pressure (76 +/- 12 versus 85 +/- 11 mmHg), central venous pressure (8 +/- 2 mmHg) and pulmonary artery occlusion pressure (6 +/- 4 mmHg). The intrathoracic blood volume index and left ventricular end-diastolic area index did not differ significantly from baseline.

CONCLUSIONS

Trendelenburg's manoeuvre caused only a slight increase of preload volume, despite marked increases in cardiac-filling pressures, without significantly improving cardiac performance.

Anaesthetic and haemodynamic effects of continuous spinal versus continuous epidural anaesthesia with prilocaine

BACKGROUND AND OBJECTIVE

To compare, using prilocaine, the effects of continuous spinal anaesthesia (CSA) and continuous epidural anaesthesia (CEA) on haemodynamic stability as well as the quality of anaesthesia and recovery in patients undergoing transurethral resection of the prostate gland.

METHODS

Thirty patients (>60 yr) were randomized into two groups. Prilocaine, 2% 40 mg, was given to patients in the CSA group, and prilocaine 1% 150mg was given to patients in the CEA group. Incremental doses were given if the level of sensory block was lower than T10 or if needed during surgery.

RESULTS

There was a significant decrease in mean arterial pressure in Group CEA compared with Group CSA (P < 0.01). The decrease in heart rate in Group CSA occurred 10 min after the first local anaesthetic administration and continued through the operation (P < 0.05). The level of sensory anaesthesia was similar in both groups. The times to reach the level of T10 and the upper level of sensory blockade (Tmax) were 18.0 +/- 4.7 and 25.3 +/- 7.0 min in Groups CSA and CEA, respectively, and were significantly longer in Group CEA. The duration of anaesthesia was 76.8 +/- 4min and was shorter in Group CSA (P < 0.01).

CONCLUSIONS

Spinal or epidural anaesthesia administered continuously was reliable in elderly patients undergoing transurethral resection of the prostate. Continuous spinal anaesthesia had a more rapid onset of action, produced more effective sensory and motor blockade and had a shorter recovery period. Prilocaine appeared to be a safe local anaesthetic for use with either continuous spinal anaesthesia or continuous epidural anaesthesia.

Cortical activity assessed by Narcotrend in relation to haemodynamic responses to tracheal intubation at different stages of cortical suppression and reflex control

BACKGROUND AND OBJECTIVE

Many anaesthesiologists still interpret haemodynamic responses as signs of insufficient cortical suppression. The aim was to illustrate how haemodynamics may only poorly reflect the level of cortical suppression and that electroencephalographic monitoring could indicate different relationships between cortical effects and haemodynamics.

METHODS

Anaesthesia was induced with thiopental (7 mg kg(-1)), and fentanyl (2 microg kg(-1)) with succinylcholine (1.5 mg kg(-1)) for neuromuscular blockade in the 11 patients of Group 1. In Group 2 (n = 15), thiopental (7 mg kg(-1)) and succinylcholine (1.5 mg kg(-1)) were given. In Group 3, the patients (n = 13) received thiopental (7 mg kg(-1)), fentanyl (2 microg kg(-1)) and cisatracurium (0.1 mg kg(-1)), and they were intubated 3 min later than the patients in Groups 1 and 2. We determined conventional electroencephalographic (EEG) variables and classified 14 EEG stages in real-time ranging from A (= 1), indicating full wakefulness, to F1 (= 14), at profound cortical suppression.

RESULTS

All groups had profound cortical suppression 45 s after thiopental administration, which rapidly decreased (EEG stage, 11 (6-13) versus 7 (2-13) at 4 min, P < 0.0001). Decreasing EEG stages were associated with increasing SEF 95, relative alpha and beta power and decreasing relative delta power. During tracheal intubation, profound cortical suppression remained unchanged in Groups 1 and 2. In Group 3, cortical suppression had decreased before laryngoscopy (P < 0.005). In Group 2, 11 patients had heart rate responses to tracheal intubation, whereas only two responded in Group 1 (P = 0.015) and three in Group 3 (P = 0.02). Thirteen patients in Group 2 had arterial pressure responses, and five in Group 1 (P = 0.038). Circulatory responses did not differ between Groups 1 and 3.

CONCLUSIONS

Electroencephalographic monitoring was suitable to indicate in real-time that haemodynamics only poorly reflect rapidly changing levels of cortical suppression, and how haemodynamics and cortical activity depend on the applied combination of hypnotic and analgesic drugs during anaesthesia induction with thiopental.

Increasing the injection volume by dilution improves the onset of motor blockade, but not sensory blockade of ropivacaine for brachial plexus block

BACKGROUND AND OBJECTIVE

Ropivacaine used for axillary plexus block provides effective motor and sensory blockade. Varying clinical dosage recommendations exist. Increasing the dosage by increasing the concentration showed no improvement in onset. We compared the behaviour of a constant dose of ropivacaine 150 mg diluted in a 30, 40 or 60 mL injection volume for axillary (brachial) plexus block.

METHODS

A prospective, randomized, observer-blinded study on patients undergoing elective hand surgery was conducted in a community hospital. Three groups of patients with a constant dose of ropivacaine 150 mg, diluted in 30,40 or 60 mL NaCl 0.9%, for axillary plexus blockade were compared for onset times of motor and sensory block onset by assessing muscle strength, two-point discrimination and constant-touch sensation.

RESULTS

Increasing the injection volume of ropivacaine 150 mg to 60 mL led to a faster onset of motor block, but not of sensory block, in axillary plexus block, compared with 30 or 40 mL volumes of injection.

CONCLUSIONS

The data show that the onset of motor, but not of sensory block, is accelerated by increasing the injection volume to 60 mL using ropivacaine 150 mg for axillary plexus block. This may be useful for a more rapid determination of whether the brachial plexus block is effective. However, when performing surgery in the area of the block, sensory block onset seems more important.

Cost considerations in the use of anaesthetic drugs

Anaesthetic drugs typically comprise approximately 5% or less of a hospital pharmacy budget, yet they are a common target for cost reduction measures. In particular, there is considerable pressure to use less costly products where alternatives exist and to limit the introduction of expensive new items. In considering strategies to reduce a departmental drug budget, or in defending against restrictions imposed from outside, it is important to consider all of the costs associated with anaesthetic drug delivery. These costs comprise not only the expense of the anaesthetic drugs themselves, but also fixed and variable costs associated with their delivery and related to their effects. Elimination of drug waste will always be beneficial, since it has no direct effect on the patient yet clearly reduces cost. Waste is by no means confined to anaesthetic drugs, however. Using less expensive drugs may appear an attractive option and can reduce costs, provided that patient outcome is in no way affected. Rarely is this the case. Once patient care is modified, through changes in recovery times or complication rates, determining the true cost of the intervention becomes essential; there may be increases in indirect costs which dwarf the apparent savings. Sometimes indirect costs will rise by a lesser amount than savings in direct costs, such that there is still an overall benefit but less than that originally anticipated. Exactly how indirect effects result in indirect costs is highly variable. The requirement for additional drugs or supplies to treat an adverse event, such as emesis, will always have an associated cost. Delayed recovery or prolonged hospital stay will waste operating room time or increase the amount of time that a patient requires nursing care, but whether this carries an associated cost depends on what the staff would otherwise have been doing. Depending on the employment method, staff may have been sent home early (with less pay) or employed at identical cost but with less to do. Many studies which purport to consider all costs either ignore such issues, or make invalid assumptions. These issues are complex, but anyone involved with decisions concerning anaesthetic costs should be familiar with the underlying principles and be able to make a rational assessment of the likely indirect costs in their own institution.

The use of propofol for its antiemetic effect: a survey of clinical practice in the United States

STUDY OBJECTIVES

To investigate the use of propofol by anesthesiologists for its antiemetic effect and to compare our findings with published evidence.

DESIGN

Anonymous survey of U.S. anesthesiologists.

SETTING

American Society of Anesthesiologists' annual meeting.

MEASUREMENTS AND MAIN RESULTS

One hundred fifty anesthesiologists were surveyed on how they use propofol to achieve an antiemetic effect. A large majority (84%) of the anesthesiologists surveyed stated they used propofol for its antiemetic effect: 63% of those used propofol for induction only for cases lasting <1 h to achieve an antiemetic effect. In addition 37% used a "sandwich" technique, using propofol at the beginning and end of a case for a similar purpose. There is evidence that the antiemetic effect of propofol is associated with a defined plasma concentration range; mean, 343 ng/mL (10-90% confidence intervals [CI] 200-600 ng/mL). Simulation data demonstrated that after propofol 2 mg/kg, its concentration will drop below 350 ng/mL at 32 min. After 2 mg/kg and 20 mg within 10 min of the end of surgery, its concentration will drop below 350 ng/mL by 7 min after the 20 mg bolus dose. This finding suggests that the plasma concentrations of propofol, when used in these cases, will be below the effective range of antiemetic effect.

CONCLUSIONS

Many anesthesiologists used propofol for its antiemetic effect. There is strong evidence for its antiemetic efficacy after anesthesia maintained by a propofol infusion and also for its use in the postanesthesia care unit (PACU). However, there is little evidence to support its use purely at induction of anesthesia or as part of a "sandwich" technique in an attempt to reduce postoperative nausea and vomiting. This is especially true in cases lasting longer than a few minutes.

Influence of thiopental and propofol on postoperative cognitive recovery in the elderly patient undergoing general anesthesia

STUDY OBJECTIVE

To assess mental and psychomotor recovery following induction of anesthesia with thiopental or propofol in elderly patients undergoing general anesthesia.

DESIGN

Randomized, prospective, double-blind study.

SETTING

Large referral hospital.

PATIENTS

40 elderly patients ASA physical status I-III (> 65 years) undergoing abdominopelvic surgery with an estimated surgical time of at least 90 minutes.

INTERVENTIONS

All patients received combined epidural-general anesthesia. After establishing a T6 sensory blockade, patients were randomized to receive either thiopental or propofol for induction of general anesthesia. The induction drug was slowly titrated until loss of eyelash reflex was noted. Thereafter, all patients received desflurane (2% to 3% end-tidal) and 70% nitrous oxide (N2O) in oxygen for maintenance of general anesthesia. To facilitate tracheal intubation, intravenous alfentanil 10 micrograms/kg and atracurium 0.4 mg/kg were administered. Perioperative analgesia was maintained with epidural bupivacaine.

MEASUREMENTS AND MAIN RESULTS

A digit substitution test (DSST) and shape-sorter test, as well as patient-generated 100-mm visual analog score (VAS; 0 = minimal and 100 = maximal) for anxiety, sleepiness, and coordination, were performed during the preanesthetic interview, on postanesthesia care unit admission, and at 15, 45, 90, and 120 minutes thereafter. To induce loss of consciousness, either thiopental 2.5 +/- 1.0 mg/kg or propofol 1.6 +/- 0.6 mg/kg was administered. The mean anesthetic time was 109 +/- 30 minutes and 114 +/- 38 minutes for the thiopental and propofol groups, respectively. Emergence, extubation, and orientation times, as well as time to follow commands, were unaffected by patient randomization. Similarly, the DSST and shape-sorter tests, in addition to the patient-generated VAS for pain, anxiety, and coordination, were similar among groups. However, irrespective of treatment modality, return to baseline digit substitution and shape-sorter scores were significantly delayed (p < 0.01).

CONCLUSION

When compared to thiopental, propofol does not facilitate improved cognitive recovery in geriatric patients undergoing prolonged surgery.

Target-controlled propofol vs. sevoflurane: a double-blind, randomised comparison in day-case anaesthesia

We compared target-controlled propofol with sevoflurane in a randomised, double-blind study in 61 day-case patients. Anaesthesia was induced with a propofol target of 8 microgram.ml-1 or 8% sevoflurane, reduced to 4 microgram.ml-1 and 3%, respectively, after laryngeal mask insertion and subsequently titrated to clinical signs. Mean (SD) times to unconsciousness and laryngeal mask insertion were significantly shorter with propofol [50 (9) s and 116 (33) s, respectively] than with sevoflurane [73 (14) s and 146 (29) s; p < 0.0001 and p = 0.0003, respectively]; however, these differences were not apparent to the blinded observer. Propofol was associated with a higher incidence of intra-operative movement (55 vs. 10%; p = 0.0003), necessitating more adjustments to the delivered anaesthetic. Emergence was faster after sevoflurane [5.3 (2.2) min vs. 7.1 (3.7) min; p = 0.027], but the inhaled anaesthetic was associated with more nausea and vomiting (30 vs. 3%; p = 0.006), which delayed discharge [258 (102) min vs. 193 (68) min; p = 0.005]. Direct costs were lower with sevoflurane but nausea would have increased indirect costs. Patient satisfaction was high (>/= 90%) with both techniques. In conclusion, both techniques had advantages and disadvantages for day-case anaesthesia.

The induction, maintenance, and recovery characteristics of spinal versus general anesthesia in elderly patients

STUDY OBJECTIVE

To compare the induction and recovery profiles of three combinations of general anesthesia when used as an alternative to spinal anesthesia for elderly patients.

DESIGN

Randomized, prospective, open-label study.

SETTING

Large referral hospital.

PATIENTS

100 [ASA physical status I, II, and III] patients over 60 years of age undergoing brief transurethral surgery.

INTERVENTIONS

In Groups Propofol-Propofol (P-P), Propofol-Isoflurane (P-I), and Propofol-Desflurane (P-D), anesthesia was induced with fentanyl (1 to 2 micrograms/kg i.v.) and propofol (1.0 to 2.0 mg/kg i.v.) and maintained with 70% nitrous oxide in oxygen and either a propofol infusion (75 to 150 micrograms/kg/min) or isoflurane (end-tidal 0.7% to 1.2%) or desflurane (end-tidal 1% to 4%), respectively. After induction, a laryngeal mask airway was placed and spontaneous ventilation was maintained. In Group Spinal (S), 1.5 ml 4% lidocaine (60 mg), in an equal volume of 10% dextrose, was administered intrathecally.

MEASUREMENTS AND MAIN RESULTS

Induction and recovery characteristics were compared. Induction with propofol was technically easier and significantly (medp < 0.0001) faster (4.6 +/- 1.7 min, 4.7 +/- 2.2 min, and 3.8 +/- 1.4 min for Groups P-P, P-I, and P-D, respectively) than induction of spinal anesthesia (9.3 +/- 3.4 min). During the induction period, mean arterial blood pressure and heart rate were significantly higher in Group S. Emergence, extubation, and orientation times were similar among the general anesthesia treatment groups. In Group S, patient-generated pain scores were lower (p < 0.05) and recovery room admission longer (p < 0.001). Time to return to baseline digit symbol substitution test (DSST) scores was marginally improved in Groups P-P and P-D when compared to Group P-I. Postoperative nausea, sleepiness, anxiety, and coordination were unaffected by the treatment modality.

CONCLUSION

General anesthesia with propofol and desflurane facilitates shorter induction and recovery times without adversely affecting patient comfort. Therefore, this technique may be preferable to spinal anesthesia for elderly patients undergoing short transurethral surgical procedures.

Recovery characteristics using single-breath 8% sevoflurane or propofol for induction of anaesthesia in day-case arthroscopy patients

We studied the induction and recovery characteristics following inhalational induction with 8% sevoflurane in nitrous oxide and oxygen compared with intravenous propofol in 40 patients presenting for arthroscopy of the knee. Patients were randomly allocated to receive either induction agent, and anaesthesia was then maintained with sevoflurane in oxygen and nitrous oxide. A computerised test of hand--eye co-ordination and a p-deletion test were used to measure psychomotor recovery. The sevoflurane group had a faster onset of anaesthesia time. No significant differences between the groups were found in time to eye opening or psychomotor tests. Nausea and vomiting scores were significantly higher at 30 min in the sevoflurane group (p = 0.04); this difference was no longer significant by 90 min. We conclude that inhalational induction with sevoflurane in these patients has no important clinical advantages and causes more nausea and vomiting than propofol.

Nausea and vomiting following thyroid and parathyroid surgery

STUDY OBJECTIVES

To determine the incidence of postoperative nausea and vomiting (PONV) following thyroid and parathyroid surgery. To determine whether PONV is reduced when propofol is used for maintenance of anesthesia as compared to isoflurane and to evaluate the costs and resource consumption associated with these two anesthetic regimens.

DESIGN

Randomized, prospective study.

SETTING

University-affiliated hospital--a referral center for endocrinologic surgery.

PATIENTS

118 ASA physical status I and II patients, aged 18 years and older, undergoing elective thyroid or parathyroid surgery.

INTERVENTIONS

Patients received either isoflurane (0.5 to 1.3% end-tidal) or propofol (50 to 200 micrograms/kg/min) for maintenance of anesthesia. All patients received propofol for induction of anesthesia, succinylcholine or vecuronium, nitrous oxide, and fentanyl. Prophylactic antiemetics were not administered. Postoperative pain was treated with ketorolac, fentanyl, or acetaminophen.

MEASUREMENTS AND MAIN RESULTS

Signs and symptoms of nausea and vomiting were graded on a four point scale as 1 = no nausea; 2 = mild nausea; 3 = severe nausea; 4 = retching and/or vomiting. Grades 3 and 4 were grouped together as PONV. The combined incidence of PONV was 54% over the 24-hour postoperative evaluation period. PONV was significantly more common in patients receiving isoflurane than propofol for maintenance of anesthesia (64% vs. 44%). In women (n = 87), the incidence of PONV was significantly greater in those patients who received isoflurane than those who received propofol for maintenance (71% vs. 42%). However, in men (n = 31), there was no significant difference in PONV between anesthetic regimens (47% with isoflurane vs. 50% with propofol). There were no differences in the duration of stay in the postanesthesia care unit, time to discharge from the hospital, or local wound complications (hematomas) between groups. The use of propofol for maintenance of anesthesia was associated with an additional cost, relative to the isoflurane group, of $54.26 per patient.

CONCLUSION

Patients undergoing thyroid or parathyroid surgery are at high risk for the development of PONV. Propofol for maintenance of anesthesia, although more expensive than isoflurane, reduces the rate of PONV in women.

Desflurane for outpatient general anesthesia in third molar extraction cases

PURPOSE

The purpose of this study was to evaluate the use of desflurane, a new volatile anesthetic agent, in a standardized endotracheal anesthetic technique for the removal of third molars in ambulatory patients.

PATIENTS AND METHODS

Data were kept on 50 American Society of Anesthesiology (ASA) Class I and II patients undergoing oral endotracheal general anesthesia for removal of third molars. A standardized anesthetic technique was used on all patients. Induction was achieved with a bolus of propofol followed by neuromuscular paralysis with succinylcholine and then intubation. A 70% nitrous oxide, 30% oxygen, and desflurane mixture was titrated until there was no movement, and a local anesthetic was administered. The procedure was then completed in a standard fashion. The parameters measured included the length of surgery, the time from gas shutoff to extubation, the time from arrival in the postanesthesia care unit to achieving an Aldrete system score for discharge with an escort, the incidence of nausea and vomiting, and amnesia of the procedure.

RESULTS

This study showed that the use of desflurane as the primary anesthetic agent for procedures of less than 1 hour is a useful technique. The agent is expensive, but the decreased recovery time and minimal side effects may offset this expense.

CONCLUSION

The desflurane anesthetic technique provides a satisfactory surgical environment in selected patients. It results in rapid postanesthesia recovery and discharge times, thus reducing costs.

Total intravenous anaesthesia with propofol or inhalational anaesthesia with isoflurane for major abdominal surgery. Recovery characteristics and postoperative oxygenation--an international multicentre study

Two hundred and ten adult patients undergoing open cholecystectomy, vagotomy or gastrectomy were included in a randomised multicentre study to compare postoperative nausea and vomiting, oxygen saturations for the first three postoperative nights, time to return of gastrointestinal function, mobilisation, and discharge from the hospital following induction and maintenance of anaesthesia with propofol and alfentanil or with thiopentone, nitrous oxide, isoflurane and alfentanil. Recovery from anaesthesia was significantly faster in the propofol group (mean (SD) times to eye opening and giving correct date of birth of 14.0 (SD 13.8) and 25.5 (SD 29.5) minutes, and 18.5 (SD 14.8) and 35.5 (SD 37.2) minutes in the propofol and isoflurane groups respectively). There was significantly less nausea in the propofol group (15.4%) than in the isoflurane group (33.7%) in the first two postoperative hours (p < 0.003) but not thereafter. There were no significant differences between the groups in any other recovery characteristics. The incidence of hypoxaemia (arterial oxygen saturation less than 93%) was close to 70% in both groups for the first three postoperative nights, indicating the need for oxygen therapy after major abdominal surgery.

The comparative effects of sevoflurane versus propofol in the induction and maintenance of anesthesia in adult patients

A randomized, prospective study was performed at four institutions to compare anesthetic induction, maintenance, and recovery characteristics between sevoflurane- and propofol-based anesthesia in 186 ASA physical status I and 11 patients undergoing elective surgical procedures of 1-3 h. Group 1 (n = 93) patients received sevoflurane-nitrous oxide for both induction and maintenance of anesthesia while Group 2 (n = 93) received propofol-nitrous oxide anesthesia. Induction of anesthesia and tracheal intubation times were significantly shorter with propofol (2.21 +/- 0.2 min, 5.11 +/- 0.3 min, respectively) than with sevoflurane (3.11 +/- 0.2 min, 7.21 +/- 0.3 min, respectively). Emergence times after sevoflurane (8.81 +/- 1.2 min) were significantly shorter than with propofol (13.21 +/- 1.2 min). Overall frequency of complication-free induction, maintenance, and emergence did not differ between the two anesthetic groups. However, side effects involving airway excitement were more prevalent during mask induction with sevoflurane as compared to propofol. Patients in the sevoflurane group were oriented and required postoperative analgesia much earlier than those who received propofol. Both groups were hemodynamically stable throughout the study period. The incidence of postoperative nausea, vomiting, and pain-discomfort scores were similar between the two groups. Urinary specific gravity decreased in the sevoflurane-treated group while serum creatinine and urinary pH were unchanged from preoperative values in both groups. Sevoflurane compared favorably with propofol when used for anesthesia for elective procedures of 1-3 h duration.

A comparison between total intravenous anaesthesia using a propofol/alfentanil mixture and an inhalational technique for laparoscopic gynaecological sterilization

Thirty patients undergoing laparoscopic gynaecological sterilization, as day-cases, were randomly allocated to receive either total intravenous anaesthesia (TIVA) with a propofol and alfentanil mixture or a standard inhalational technique. Immediate recovery, as measured by times to awakening, co-operation and orientation, and psychomotor recovery, as measured by 'P' deletion studies, were not significantly different between the two groups. TIVA produced a significant reduction in post-operative nausea at both 1 and 2 h post-operatively, as measured by a visual analogue scale (P < 0.01). No patient in the TIVA group vomited whereas two vomited in the inhalational group. There were no differences between the two groups with respect to suitability for discharge home and no incidences of awareness. We conclude that TIVA with a propofol and alfentanil mixture provides satisfactory anaesthesia for gynaecological sterilization, with good recovery characteristics and a low incidence of post-operative nausea and vomiting.

Anaesthesia for short outpatient procedures. A comparison between thiopentone and propofol in combination with fentanyl or alfentanil

We studied supplementation of propofol or thiopentone anaesthesia with 0.5 or 1.0 mg alfentanil or 0.05 or 0.1 mg fentanyl for minor gynaecological outpatient procedures. Four hundred patients scheduled for elective termination of pregnancy were randomly allocated to one of eight groups. Induction agent doses, peroperative complications, complaints about pain and emesis during the postoperative period, and time to discharge were studied. Propofol compared to thiopentone was associated with a shorter time to discharge, 103 +/- 28 and 115 +/- 33 minutes respectively (P < 0.05) and anxiety during recovery was more frequent in the thiopentone group (P < 0.05). The need for postoperative reserve analgesics was less in the alfentanil group (P < 0.05). We found, however, no major differences between the supplementations tested regarding the total dose of induction agent, emesis or time to discharge. Supplementation with 1.0 mg of alfentanil to propofol was found to be the best combination tested for short outpatient procedures.

[Use of Diprivan for digestive system endoscopy]

After evaluation of the patient's clinical condition and appropriate premedication is seems reasonable to suggest for: 1. Endoscopic procedures involving the gastro-intestinal tract: slow, titrated induction, using 0.5 to 1 mg.kg-1 of propofol, until the required level of sedation has been achieved; this may or not be preceded by the injection of a low dose of midazolam (0.02 to 0.03 mg.kg-1) or of alfentanil (5 micrograms.kg-1); maintenance is achieved by bolus injections of 20 mg (up to 0.5 mg.kg-1); maintenance of spontaneous ventilation, with oxygen administration is the rule; SpO2 is monitored routinely; anaesthesia has to be performed according to the recommendations of the French Society of Anaesthesia and Intensive Care (SFAR) and the anaesthetist must be prepared to manage any incident during the endoscopy and the recovery period. 2. Procedures involving the biliary tract and the oesophagus, which require deeper anaesthesia: induction should again be titrated using a very slow infusion, with doses ranging from 0.9 to 2.2 mg.kg-1); the maintenance requires a continuous infusion, doses ranging from 4 to 6 mg.kg-1.h-1 when propofol is administered alone and from 4 to 12 mg.kg-1.h-1 when combined with an opioid; continuous oxygenation is necessary using a nasal airway; the need for intubation depends on the type of procedure and the status of the patient; the same monitoring devices and similar safety measures are required during and after procedure as for any anaesthetic or sedation, especially when it is performed in day-case patients or outside the operating theatre.

Postoperative nausea and vomiting. A comparison between intravenous and inhalation anaesthesia in breast surgery

Nausea and vomiting during the first 24 postoperative hours after breast surgery were studied. Ninety patients scheduled for elective breast surgery were randomly assigned to one of three anaesthetic methods: total intravenous anaesthesia with propofol, or propofol or thiopental for induction followed by isoflurane anaesthesia. All three groups received fentanyl for peroperative analgesia. A total of 46 (51%) patients experienced emetic sequelae: 19 (21%) complained about nausea and another 27 (30%) vomited once or more during the postoperative course. More than 50% of the patients with nausea and 70% with vomiting first suffered from these symptoms in the surgical wards after leaving the postoperative unit. Nausea and vomiting were seen in 18 (60%), 13 (43%) and 15 (50%) for the groups propofol-propofol, propofol-isoflurane and thiopental-isoflurane, respectively. In conclusion, every second patient experienced nausea or vomiting after breast surgery, the majority of these emetic symptoms occurring after leaving the postoperative unit. Propofol for induction or as a main anaesthetic did not make any major difference with regard to postoperative nausea or vomiting.

Patient evaluation of four different combinations of intravenous anaesthetics for short outpatient procedures

We studied 200 female patients (ASA group 1) scheduled for termination of pregnancy under general anaesthesia. The patients were randomly allocated to receive one of four anaesthetic combinations; (1) propofol in combination with ketamine 20 mg, (2) propofol in combination with fentanyl 0.1 mg, (3) thiopentone in combination with fentanyl 0.1 mg, (4) methohexitone in combination with fentanyl 0.1 mg. All patients were breathing oxygen in nitrous oxide 1:2. Patients' self assessments of per- and postoperative course and time to discharge were compared. No patient's response suggested light anaesthesia, but dreams were frequently experienced during anaesthesia especially among the propofol-ketamine combination (29 out of 50). Time to discharge was shortest for the groups of patients given propofol; the mean time was 93 and 96 min for the ketamine and fentanyl groups respectively. During the recovery period significantly more patients experienced pain in the ketamine-propofol group. Complaints of nausea were seen in only 15 patients, and seven patients noted psycho-mimetic side effects during recovery, without any differences between the groups. All four combinations tested offered good conditions for short outpatient procedures. However, the propofol-fentanyl combination was found to offer the best quality of anaesthesia as assessed by the patients themselves.