Low-dose clonidine and neostigmine prolong the duration of intrathecal bupivacaine-fentanyl for labor analgesia

BACKGROUND

Intrathecal (IT) opioid and local anesthetic combinations are popular for labor analgesia because of rapid, effective pain relief, but the duration of analgesia is limited. This study was undertaken to determine whether the addition of clonidine and neostigmine to IT bupivacaine-fentanyl would increase the duration of analgesia without increasing side effects for patients in labor.

METHODS

Forty-five healthy parturients in active labor were randomized to receive a 2-ml IT dose of one of the following dextrose-containing solutions using the combined spinal-epidural technique: (1) bupivacaine 2.5 mg and fentanyl 25 microg (BF); (2) BF plus clonidine 30 microg (BFC); or (3) BFC plus neostigmine 10 microg (BFCN). Pain, sensory levels, motor block, side effects, maternal vital signs, and fetal heart rate were systematically assessed.

RESULTS

Patients administered BFCN had significantly longer analgesia (165+/-32 min) than those who received BF (90+/-21 min; P<0.001) or BFC (123+/-21 min; P<0.001). Pain scores, block characteristics, maternal vital signs, Apgar scores, maternal satisfaction, and side effects were similar among groups except for nausea, which was significantly greater in the BFCN group (P<0.05 as compared with BFC).

CONCLUSIONS

The addition of clonidine and neostigmine significantly increased the duration of analgesia from IT bupivacaine-fentanyl during labor, but neostigmine caused more nausea. Although serious side effects were not observed in this study, safety must be further addressed before the routine use of multiple IT drugs is advocated.

Sevoflurane provides better recovery than propofol plus fentanyl in anaesthesia for day-care surgery

To compare ease of maintenance and recovery characteristics of sevoflurane and propofol plus fentanyl in day-care anaesthesia, 60 outpatients undergoing elective surgery of up to 3 h duration were randomized to receive sevoflurane or propofol as their primary anaesthetic. Induction was always carried out with propofol, but a fentanyl bolus 5 microg kg-1 was added in the propofol group. Anaesthesia was supplemented with up to 70% N2O. Significantly shorter times to extubation (10.03 min +/- 3.2 SD vs. 17.2 +/- 7.3; P < 0.001) and emergence (10.4 +/- 3.1 vs. 16.8 +/- 6.4; P < 0.001) were observed in the sevoflurane group. Patients treated with sevoflurane felt less confused, showed better performances in the digit symbol substitution test and achieved higher modified Aldrete scores sooner in the post-operative course. Maintenance of anaesthesia with sevoflurane produces faster emergence and recovery than propofol plus fentanyl after anaesthesia of short to intermediate duration.

Minidose bupivacaine-fentanyl spinal anesthesia for surgical repair of hip fracture in the aged

BACKGROUND

Spinal anesthesia for surgical repair of hip fracture in the elderly is associated with a high incidence of hypotension. The synergism between intrathecal opioids and local anesthetics may make it possible to achieve reliable spinal anesthesia with minimal hypotension using a minidose of local anesthetic.

METHODS

Twenty patients aged > or = 70 yr undergoing surgical repair of hip fracture were randomized into two groups of 10 patients each. Group A received a spinal anesthetic of bupivacaine 4 mg plus fentanyl 20 microg, and group B received 10 mg bupivacaine. Hypotension was defined as a systolic pressure of < 90 mmHg or a 25% decrease in mean arterial pressure from baseline. Hypotension was treated with intravenous ephedrine boluses 5-10 mg up to a maximum 50 mg, and thereafter by phenylephrine boluses of 100-200 microg.

RESULTS

All patients had satisfactory anesthesia. One of 10 patients in group A required ephedrine, a single dose of 5 mg. Nine of 10 patients in group B required vasopressor support of blood pressure. Group B patients required an average of 35 mg ephedrine, and two patients required phenylephrine. The lowest recorded systolic, diastolic, and mean blood pressures as fractions of the baseline pressures were, respectively, 81%, 84%, and 85% versus 64%, 69%, and 64% for group A versus group B.

CONCLUSIONS

A "minidose" of 4 mg bupivacaine in combination with 20 microg fentanyl provides spinal anesthesia for surgical repair of hip fracture in the elderly. The minidose combination caused dramatically less hypotension than 10 mg bupivacaine and nearly eliminated the need for vasopressor support of blood pressure.

Clinical pharmacokinetics of transdermal opioids: focus on transdermal fentanyl

Transdermal delivery allows continuous systemic application of opioids through the intact skin. This review analyses the pharmacokinetic properties of transdermal opioid administration in the context of clinical experience, with a focus on fentanyl. A transdermal therapeutic system (TTS) for fentanyl has been developed. The amount of fentanyl released is proportional to the surface area of the TTS, which is available in different sizes. After the first application of a TTS, a fentanyl depot concentrates in the upper skin layers and it takes several hours until clinical effects are observed. The time from application to minimal effective and maximum serum concentrations is 1.2 to 40 hours and 12 to 48 hours, respectively. Steady state is reached on the third day, and can be maintained as long as patches are renewed. Within each 72-hour period, serum concentrations decrease gradually over the second and third days. When a TTS is removed, fentanyl continues to be absorbed into the systemic circulation from the cutaneous depot. The terminal half-life for TTS fentanyl is approximately 13 to 25 hours. The interindividual variability of serum concentrations, partly caused by different clearance rates, is markedly larger than the intraindividual variability. The effectiveness of TTS fentanyl was first demonstrated in acute postoperative pain. However, the slow pharmacokinetics and large variability of TTS fentanyl, together with the relatively short duration of postoperative pain, precluded adequate dose finding and led to inadequate pain relief or, especially, a high incidence of respiratory depression; such use is now contraindicated. Conversely, in cancer pain, TTS fentanyl offers an interesting alternative to oral morphine, and its effectiveness and tolerability in this indication has been demonstrated by a number of trials. Its usefulness in chronic pain of nonmalignant origin remains to be confirmed in controlled trials. In general, TTS fentanyl produces the same adverse effects as other opioids, mainly sedation, nausea, vomiting and constipation. In comparison with oral morphine, TTS fentanyl causes fewer gastrointestinal adverse events. The risk of hypoventilation is comparatively low in cancer patients. Sufentanil and buprenorphine may also be suitable for transdermal delivery, but clinical results are not yet available. Transdermal morphine is only useful if applied to de-epithelialised skin. However, iontophoresis may allow transdermal administration of opioids, including morphine, with a rapid achievement of steady state concentrations and the ability to adjust delivery rates. This would be beneficial for acute and/or breakthrough pain, and initial clinical trials are in progress.

Continuous epidural analgesia with bupivacaine-fentanyl versus patient-controlled analgesia with i.v. morphine for postoperative pain relief after knee ligament surgery

BACKGROUND

Both epidural analgesia and intravenous patient-controlled analgesia (PCA) have been found efficacious after various types of surgery. We compared the efficacy, safety, side effects and patient satisfaction of these methods in a randomized double-blind fashion after elective anterior cruciate ligament reconstruction of the knee.

METHODS

Fifty-six patients had an epidural catheter placed at the L2-L3 interspace. Spinal anaesthesia with 15 mg of plain bupivacaine 5 mg/ml was performed at the L3-L4 interspace. After surgery the patients were randomly divided into three groups: 19 received a continuous epidural infusion with bupivacaine 1 mg/ml and fentanyl 10 mg/ml (F10), 19 patients received bupivacaine 1 mg/ml and fentanyl 5 microg/ml (F5) and 18 patients received saline (S). The rate of the epidural infusions was 0.1 ml kg(-1) h(-1). Each patient could also use an intravenous (i.v.) PCA device with 40 microg/kg bolus doses of morphine with a lockout period of 10 min and a maximum dose 240 microg kg(-1) h(-1). At the end of surgery ketoprofen 100 mg i.v. was given and continued orally three times a day. Patients were assessed for pain with a visual analogue scale (VAS) at rest and during activity, side effects and satisfaction at 3, 9 and 20 h.

RESULTS

Both epidural infusions (F10, F5) provided better analgesia than epidural saline plus i.v. PCA (S) (P<0.05). There was slightly less nausea in the S group (NS). In spite of the difference in the quality of pain relief, there was no difference between the groups in patient satisfaction regarding analgesic therapy.

CONCLUSION

Epidural infusion of fentanyl (1 microg kg(-1) h(-1) or 0.5 microg kg(-1) h(-1)) and bupivacaine (0.1 mg kg(-1) h(-1)) provided better pain relief but more side effects than intravenous morphine patient-controlled analgesia after knee ligament surgery. Almost all patients in all groups were satisfied with their pain relief.

Use of an illuminated flexible catheter for light-guided tracheal intubation through the intubating laryngeal mask by nurses

We evaluated the ability of inexperienced personnel in using a prototype illuminated flexible catheter to assist tracheal intubation through the intubating laryngeal mask in anaesthetised, paralysed patients. The device consists of a completely flexible thin plastic catheter, a bulb attached to its distal end and a 15-mm concentric adapter at its proximal end. The illuminated catheter is placed into a straight silicone tracheal tube in such a way that the bulb is placed at the distal end of the tracheal tube. Six nurses inexperienced in tracheal intubation followed a 2-hr training program by using the device through the intubating laryngeal mask in a mannequin and then intubated 10 patients each, with instruction from an anaesthetist. All patients (n=60) were ASA 1-2, scheduled to undergo general anaesthesia for elective surgery. After fentanyl/propofol induction the intubating laryngeal mask was inserted. When an adequate airway was established, patients received atracurium and the endotracheal tube preloaded with the device was inserted through the intubating laryngeal mask and by observing the glow in the neck was advanced into the trachea. The final outcome and the duration of the procedure were recorded. The intubating laryngeal mask was inserted successfully in all patients. The success rate of intubation was 57/60 (95%); 38 patients at first attempt and 19 after two or three attempts. The mean (+/-SD) duration of the procedure in the first five patients in the series of each nurse was 74+/-40 s while in the last five patients it was diminished to 52+/-23 s (P=0.01). We conclude that the described methodology has the potential for more widespread use of tracheal intubation through the intubating laryngeal mask even by inexperienced personnel.

[Experience in the use of propofol in surgical interventions in children]

The adequacy of anesthesia with propofol is evaluated in 48 children aged 3 months to 7 years (ASA I-III) subjected to abdominal and urological interventions. The children were divided into groups administered different general anesthesias: 9 children aged 3-7 years operated under total intravenous anesthesia (TIVA) with propofol and fentanyl and 39 children aged 3 months to 6 years operated under TIVA with propofol, ketamine, and fentanyl. The efficiency of anesthesia was evaluated by electroencephalography and hemodynamic monitoring. TIVA with propofol, fentanyl, and ketamine did not notably decrease arterial pressure during induction; the course of anesthesia and recovery ran a smooth course; the doses of propofol and fentanyl were appreciably decreased. Use of this protocol in children aged under 3 years ensured adequate anesthesia with the minimum risk of hemodynamic disorders.

[State of the sympathoadrenal system and hemodynamics in children during congenital heart defect surgery with high thoracic epidural anesthesia using lidocaine-clofelin]

Effects of high thoracic epidural anesthesia (HTEA) on the hemodynamics and sympathoadrenal system were studied in patients during cardiopulmonary bypass surgery. In 55 patients aged 1-14 years, HTEA was used in combination with oxygen-air-halothane anesthesia. In one group lidocaine and fentanyl were used for HTEA and in another clonidine and lidocaine. In the control, standard intravenous fentanyl-diazepam anesthesia was combined with oxygen-air-halothane anesthesia. In the clonidine-lidocaine group the endocrine stress response was decreased in comparison with other groups even without narcotics; hemodynamics was stable even in patients with NYHA class III-IV.

Propofol anesthesia for craniotomy: a double-blind comparison of remifentanil, alfentanil, and fentanyl

For patients undergoing craniotomy, it is desirable to have stable and easily controllable hemodynamics during intense surgical stimulation. However, rapid postoperative recovery is essential to assess neurologic function. Remifentanil, an ultra-short-acting mu-opioid receptor agonist, may be the ideal agent to confer the above characteristics. In this prospective randomized study, we compared the hemodynamic stability, recovery characteristics, and the dose of propofol required for maintaining anesthesia supplemented with an infusion of remifentanil, alfentanil, or fentanyl in 34 patients scheduled for supratentorial craniotomy. With routine monitors in place, anesthesia was induced with propofol (2-3 mg/kg), atracurium (0.5 mg/kg), and either remifentanil (1 microg/kg), alfentanil (10 microg/kg), or fentanyl (2 micro/kg). The lungs were ventilated with O2/air to mild hypocapnia. Anesthesia was maintained with infusions of propofol (50-100 microg/kg/min) and either remifentanil (0.2 microg/kg/min), alfentanil (20 microg/kg/h), or fentanyl (2 microg/kg/h). There were no significant differences among the groups in the dose of propofol maintenance required, heart rate, or mean arterial pressure. However, the time to eye opening (minutes) was significantly shorter in the remifentanil compared to the alfentanil group (6+/-3; 21+/-14; P = 0.0027) but not the fentanyl group (15+/-9). We conclude that remifentanil is an appropriate opioid to use in combination with propofol during anesthesia for supratentorial craniotomy.

[Characteristics of general anesthesia in video thoracoscopic surgery in children]

Videothoracoscopic operations were carried out in 54 patients aged 6 months to 14 years. Two variants of general anesthesia were used: bolus injection of fentanyl in combination with calypsol and infusion of fentanyl in combination with subnarcotic doses of fluothane. One-lung ventilation was carried out in all children. Hemodynamic status, gaseous composition of the blood, and cerebral bloodflow were monitored during general anesthesia.

Cerebral hemodynamic effects of morphine and fentanyl in patients with severe head injury: absence of correlation to cerebral autoregulation

BACKGROUND

The current study investigates the effects of morphine and fentanyl upon intracranial pressure and cerebral blood flow estimated by cerebral arteriovenous oxygen content difference and transcranial Doppler sonography in 30 consecutive patients with severe head injury in whom cerebrovascular autoregulation previously had been assessed.

METHODS

Patients received morphine (0.2 mg/kg) and fentanyl (2 microg/kg) intravenously over 1 min but 24 h apart in a randomized fashion. Before study, carbon dioxide reactivity and autoregulation were assessed. Intracranial pressure, mean arterial blood pressure, and cerebral perfusion pressure were repeatedly monitored for 1 h after the administration of both opioids. Cerebral blood flow was estimated from the reciprocal of arteriovenous oxygen content difference and middle cerebral artery mean flow velocity using transcranial Doppler sonography.

RESULTS

Although carbon dioxide reactivity was preserved in all patients, 18 patients (56.7%) showed impaired or abolished autoregulation to hypertensive challenge, and only 12 (43.3%) had preserved autoregulation. Both morphine and fentanyl caused significant increases in intracranial pressure and decreases in mean arterial blood pressure and cerebral perfusion pressure, but estimated cerebral blood flow remain unchanged. In patients with preserved autoregulation, opioid-induced intracranial pressure increases were not different than in those with impaired autoregulation.

CONCLUSIONS

The authors conclude that both morphine and fentanyl moderately increase intracranial pressure and decrease mean arterial blood pressure and cerebral perfusion pressure but have no significant effect on arteriovenous oxygen content difference and middle cerebral artery mean flow velocity in patients with severe brain injury. No differences on intracranial pressure changes were found between patients with preserved and impaired autoregulation. Our results suggest that other mechanisms, besides the activation of the vasodilatory cascade, also could be implicated in the intracranial pressure increases seen after opioid administration.

Effects of neck position and head elevation on intracranial pressure in anaesthetized neurosurgical patients: preliminary results

This study reports the collective effect of the positions of the operating table, head, and neck on intracranial pressure (ICP) of 15 adult patients scheduled for elective intracerebral surgery. Patients were anesthetized with propofol, fentanyl, and maintained with a propofol infusion and fentanyl. Intracranial pressure was recorded following 20 minutes of stabilization after induction at different table positions (neutral, 30 degrees head up, 30 degrees head down) with the patient's neck either 1) straight in the axis of the body, 2) flexed, or 3) extended, and in the five following head positions: a) head straight, b) head angled at 45 degrees to the right, c) head angled at 45 degrees to the left, d) head rotated to the right, or e) head rotated the left. For ethical reasons, only patients with ICP < or = 20 mm Hg were included. Intracranial pressure increased every time the head was in a nonneutral position. The most important and statistically significant increases in ICP were recorded when the table was in a 30 degree Trendelenburg position with the head straight or rotated to the right or left, or every time the head was flexed and rotated to the right or left-whatever the position of the table was. These observations suggest that patients with known compromised cerebral compliance would benefit from monitoring ICP during positioning, if the use of a lumbar drainage is planed to improve venous return, cerebral blood volume, ICP, and overall operating conditions.

Comparative cardiopulmonary effects of carfentanil-xylazine and medetomidine-ketamine used for immobilization of mule deer and mule deer/white-tailed deer hybrids

Three mule deer and 4 mule deer/white-tailed deer hybrids were immobilized in a crossover study with carfentanil (10 microg/kg) + xylazine (0.3 mg/kg) (CX), and medetomidine (100 microg/kg) + ketamine (2.5 mg/kg) (MK). The deer were maintained in left lateral recumbency for 1 h with each combination. Deer were immobilized with MK in 230+/-68 s (mean +/- SD) and with CX in 282+/-83 seconds. Systolic, mean and diastolic arterial pressure were significantly higher with MK. Heart rate, PaO2, PaCO2, pH, and base excess were not significantly different between treatments. Base excess and pH increased significantly over time with both treatments. Both treatments produced hypoventilation (PaCO2 > 50 mm Hg) and hypoxemia (PaO2 < 60 mm Hg). PaO2 increased significantly over time with CX. Body temperature was significantly (P<0.05) higher with CX compared to MK. Ventricular premature contractions, atrial premature contractions, and a junctional escape rhythm were noted during CX immobilization. No arrhythmias were noted during MK immobilization. Quality of immobilization was superior with MK, with no observed movement present for the 60 min of immobilization. Movement of the head and limbs occurred in 4 animals immobilized with CX. The major complication observed with both of these treatments was hypoxemia, and supplemental inspired oxygen is recommended during immobilization. Hyperthermia can further complicate immobilization with CX, reinforcing the need for supplemental oxygen.

Oral transmucosal fentanyl pretreatment for outpatient general anesthesia

The oral transmucosal formulation of fentanyl citrate (OTFC) has been reported to be an effective sedative, providing convenient and atraumatic sedation for children prior to general anesthesia or painful diagnostic procedures. Thirty-three young children (24-60 months of age) scheduled for outpatient general anesthesia for treatment of dental caries were enrolled in this randomized placebo-controlled clinical trial. To determine the effectiveness of the OTFC premedication, patient behavior was evaluated using three distinct outcome ratings. A sedation score rated behavior in the waiting room prior to OTFC as well as 10 minutes and 20 minutes after OTFC. A separation score rated the child's response to being separated from his/her parent or guardian for transport to the dental operatory. Finally, a cooperation score rated the child's acceptance of the mask induction. The OTFC formulation was well tolerated by most of the children in this study. Compared with the placebo oralet, the active OTFC improved behavior for separation from the parent (P < .05) and cooperation with the mask induction (P < .05). The duration of surgery and the time of recovery did not differ between placebo and active premedication. Side effects including respiratory and cardiovascular complications were reported more frequently in the active fentanyl group. Continuous monitoring of respiratory function is essential when using this unique and effective formulation of fentanyl for pediatric preanesthetic sedation.

Patient supplemented epidural analgesia after major abdominal surgery with bupivacaine/fentanyl or ropivacaine/fentanyl

PURPOSE

To compare analgesic efficacy and occurrence of motor block and other side effects during patient supplemented epidural analgesia (PSEA) with either ropivacaine/fentanyl or bupivacaine/fentanyl mixtures.

METHODS

In a prospective, randomized, double-blind study, 32 ASAI-III patients undergoing major abdominal surgery received an epidural catheter at the T8- T10, followed by integrated general epidural anesthesia. Postoperative epidural analgesia was provided using a patient controlled pump with either ropivacaine 0.2%/2 microg x ml(-1) fentanyl (group Ropivacaine, n = 16) or bupivacaine 0.125%/2 microg x ml(-1) fentanyl (group Bupivacaine, n = 16) [background infusion 4-6 ml x hr(-1), 1.5 ml Incremental Doses and 20 min lock out]. Verbal pain rating score, number of incremental doses, consumption of epidural analgesic solution and rescue analgesics, sedation (four-point scale), and pulse oximetry were recorded by a blind observer for 48 hr after surgery.

RESULTS

No differences in pain relief, motor block, degree of sedation, pulse oximetry and other side effects were observed between the two groups. The number of incremental doses and the volume of analgesic solution infused epidurally were higher in patients receiving the bupivacaine/fentanyl mixture (10 [0-52] I.D. and 236 [204-340] ml) than in patients receiving the ropivacaine/fentanyl solution (5 [0-50] I.D. and 208 [148-260] ml) (P = 0.03 and P = 0.05, respectively).

CONCLUSION

Using a ropivacaine 0.2%/2 microg x ml(-1) fentanyl mixture for patient supplemented epidural analgesia after major abdominal surgery provided similar successful pain relief as bupivacaine 0.125%/2 microg x ml(-1) fentanyl, but patients receiving bupivacaine/fentanyl requested more supplemental.

[State of central hemodynamics in various kinds of anesthesia during short-term ENT surgery in children]

The study was carried out in 124 children aged 4-10 years with ASA risk I or II. Group 1 consisted of 40 patients operated on under combined anesthesia with midazolam, fentanyl, and N2O, group 2 were 30 children operated on under mask anesthesia with fluothane, and nitric oxide + oxygen, group 3 patients were operated on under combined anesthesia with ketamine, midazolam, and N2O + CO2, and group 4 patients were operated on under thiopental and N2O + CO2. Cardiovascular function was evaluated by the NCCOM3-R-7 device (BoMed) by the bioimpedance method. Satisfactory cardiovascular function was observed in all groups, but the best stability was noted in the midazolam-fentanyl group. Hence, midazolam-fentanyl combination can be the method of choice in short-term ENT operations.

The use of bispectral analysis to monitor outpatient sedation

The bispectral (BIS) index has been used to interpret partial EEG recordings to predict the level of sedation and loss of consciousness in patients undergoing general anesthesia. The author has evaluated BIS technology in determining the level of sedation in patients undergoing outpatient deep sedation. These experiences are outlined in this review article. Initially, the correlation of the BIS index with traditional subjective patient evaluation using the Observer's Assessment of Alertness and Sedation (OAA/S) scale was performed in 25 subjects. In a second study, the recovery profile of 39 patients where the BIS was used to monitor sedation was compared with a control group where the monitor was not used. A strong positive relationship between the BIS and OAA/S readings was found in the initial subjects. From the recovery study, it appears that use of the BIS monitor may help titrate the level of sedation so that less drugs are used to maintain the desired level of sedation. A trend to earlier return of motor function in BIS-monitored patients was also demonstrated. BIS technology offers an objective, ordinal means of assessing the depth of sedation. This can be invaluable in comparing studies of techniques. The BIS index provides additional information to standard monitoring techniques that helps guide the administration of sedative-hypnotic agents. The trend to earlier return of motor function in BIS-monitored patients warrants further investigation.

Sedation for ambulatory endoscopy

Diagnostic and therapeutic fiberoscopy of gastrointestinal tract is often performed ambulatory and sedation is sometimes also required. Indication for sedation can be the intervention itself or the patient's psychological state. Aim of the study was to compare the effects of midazolam and combination of midazolam and fentanyl during endoscopy. Twenty eight cases were investigated: oesophagogastroduodenoscopy (n = 14) and colonoscopy (n = 14). Anaesthetics were midazolam (M) in 16 cases, midazolam-fentanyl (MF) in 12 cases. Non-invasive mean arterial pressure, pulse rate, acid-base balance and blood gases (by Astrup method) were recorded before endoscopy, at the 5th and 10th minutes of endoscopy, 15 minutes after intervention and also before emission. Pulse rate changed between 78-92/min. Mean arterial pressure appeared between 84-90 mm Hg. In MF group both were lower but there was not significant difference between the groups. The values were in normal range, there were not metabolic acidosis which needed correction. Onset of sedative effect was 2.8 min. in M group, 2.3 min. in MF group. The ability for adequate reaction returned within 11 min. in M group, within 14 min. in MF group. Fentanyl prolongs sedative effect of midazolam and offers sufficient pain relief. After 3 hours, patients could be emitted from the hospital.

Elderly coronary artery bypass graft patients with left ventricular dysfunction are hemodynamically stable after two different doses of rocuronium

OBJECTIVE

To clarify the detailed hemodynamic responses to bolus administration of 2x 95% effective dose (ED95) and 3x ED95 of rocuronium in elderly patients with left ventricular dysfunction undergoing elective coronary artery bypass grafting (CABG).

DESIGN

Prospective, randomized, clinical study.

SETTING

University hospital.

PARTICIPANTS

Twenty patients aged older than 65 who had coronary artery disease with left ventricular ejection fractions equal to or less than 40%.

INTERVENTIONS

Using invasive cardiac monitoring, the detailed hemodynamic profile was obtained before and at 2, 4, 6, 8, and 10 minutes after the injection of rocuronium.

MEASUREMENTS AND MAIN RESULTS

Minor changes in all the measured or derived hemodynamic variables within the two groups did not attain statistical significance. Except for a higher baseline and the subsequent mean arterial pressures in one group, there were neither statistically nor clinically significant differences between two different doses of rocuronium in any of the variables at any time.

CONCLUSION

The results demonstrate that bolus administration of rocuronium (2x to 3x ED95) in combination with high-dose fentanyl provides sufficient cardiovascular stability among elderly CABG patients with left ventricular dysfunction. The cardiovascular profile of the two different bolus doses was similar. Rocuronium, in both doses, appears to be a suitable agent for muscle relaxation, especially for patients who require a high degree of cardiovascular stability.

Alfentanil causes less postoperative nausea and vomiting than equipotent doses of fentanyl or sufentanil in outpatients

BACKGROUND

The relative potencies of alfentanil, fentanyl, and sufentanil as a risk factor for postoperative nausea and vomiting have not been determined. They were compared in a randomized study designed to obtain equipotent plasma concentrations of these three opioids at the beginning of the recovery period.

METHODS

The study included 274 patients treated on an outpatient basis. The steady state opioid plasma concentration providing a predicted 50% reduction of the minimum alveolar concentration of isoflurane was used to determine the relative potency of the opioids. The opioids were prepared in equal volumes at concentrations of alfentanil 150 microg/ml, fentanyl 50 microg/ml, and sufentanil 5 microg/ml and were administered in vol/kg. Anesthesia was induced in a blinded fashion with a bolus of the study opioid (0.05 ml/kg) and 4-6 mg/kg thiopental and was maintained with isoflurane (0.6-1%) in a nitrous oxide-oxygen mixture with a continuous infusion of the study opioid (0.06 ml x kg(-1) x h(-1)). If necessary, up to five additional boluses of opioid (0.02 ml/kg) could be given. This opioid administration protocol was tested by pharmacokinetic simulations.

RESULTS

The incidence of postoperative nausea and vomiting was not different in the postanesthesia care unit, but in the ambulatory surgery unit it was significantly lower for alfentanil compared with fentanyl and sufentanil (12, 34, and 35%, respectively P < 0.005). Pharmacokinetic modeling showed that the end-anesthesia opioid plasma concentrations were approximately equipotent in the three groups. However, modeling does not support that the difference between groups in the postoperative period can be explained by a more rapid disappearance of alfentanil from the plasma.

CONCLUSIONS

Alfentanil, compared with approximately equipotent doses of fentanyl and sufentanil, is associated with a lower incidence of postoperative nausea and vomiting in outpatients.

A comparison of levobupivacaine 0.125%, fentanyl 4 microg/mL, or their combination for patient-controlled epidural analgesia after major orthopedic surgery

Levobupivacaine, the isolated S(-) isomer of bupivacaine, is less cardiotoxic than racemic bupivacaine in animal studies. We studied the effectiveness of patient-controlled epidural analgesia (PCEA) with either levobupivacaine 0.125% or fentanyl 4 microg/mL alone, or a combination of levobupivacaine and fentanyl in 65 patients after total joint arthroplasty in a prospective, random, double-blinded fashion. Intraoperatively, all patients received 20 mL of 0.75% levobupivacaine. Study medication was infused at an initial rate of 4 mL/h, with additional medication available on patient demand (2 mL/10 min). The combination of levobupivacaine and fentanyl produced better analgesia (longer time to first PCEA request; P = 0.007 combination versus fentanyl and P = 0.006 combination versus levobupivacaine) than either drug alone. Patients in the levobupivacaine groups had appreciable sensory blockade to pinprick with minimal motor impairment. Resting and dynamic visual analog scale pain scores were lower in the combination group than in the plain fentanyl group at 6 (P = 0.022 and 0.036) and 12 h (P = 0.002 and 0.001). The 24-h overall patient- and investigator-rated visual analog scale pain scores were also lower in the combination group (resting P = 0.007, dynamic P = 0.005). There was no significant difference among the groups in the incidence of postoperative nausea (26.2%), pruritus (9.2%), hypotension (23.1%), or sedation (0%). We conclude that the analgesic effects of levobupivacaine 0.125% and fentanyl (4 microg/mL) are additive and beneficial for the management of orthopedic surgical pain by the PCEA method. Patients in this study began demand-dosing later, reported lower pain scores, and had no greater risk of adverse events than those who were given either levobupivacaine or fentanyl alone.

IMPLICATIONS

We demonstrated a significant additive effect of the combination of levobupivacaine (0.125%) and fentanyl (4 microg/mL), compared with either drug alone, when using patient-controlled epidural analgesia in patients after total joint arthroplasty.