Evaluation of thoracic epidural catheter position and migration using radio-opaque catheters.

Migration of thoracic epidural radio-opaque catheters was evaluated in 25 patients scheduled for thoracic surgery in the supine position (n = 5) or in the lateral position with lateral extension of the thoracic spine (n = 20). Chest radiography was performed daily for 3 days after operation. Eighty-nine per cent of catheter tips were visualised in the epidural space. The catheter tip position was unchanged in all patients operated upon in the supine position. In the group operated upon in the lateral position, the catheter tip retracted from day 1 to day 2 by an average of 0.69 cm (SD 1.08; p < 0.05); from day 2 to day 3 the average retraction was 0.35 cm (SD 0.67; p < 0.05).

Pharmacokinetics of epidurally administered nicomorphine with its metabolites and glucuronide conjugates in patients undergoing pulmonary surgery during combined epidural local anaesthetic block and general anaesthesia.

After epidural administration of 15 mg 3, 6-dinicotinoylmorphine (nicomorphine) in 10 patients undergoing pulmonary surgery, the parent compound was quickly metabolized into the metabolites 6-mononicotinoylmorphine and morphine. The mean apparent half-lives (+/- SD) of elimination were 10 min (0.165 h +/- 0.053 h) for 3,6-dinicotinoylmorphine and 1.77 h +/- 1.23 h for 6-mononicotinoylmorphine. Morphine is subsequently metabolized into morphine-3-glucuronide and morphine-6-glucuronide. The apparent half-lives of morphine, morphine-3-glucuronide, and morphine-6-glucuronide are similar: 3.63 h +/- 1.63 h, 4.10 h +/- 0.57 h, and 4.20 h +/- 1.64 h respectively. The possible glucuronide conjugate of 6-mononicotinoylmorphine was not detected. The prodrug 3,6-dinicotinoylmorphine was biotransformed into three active compounds: 6-mononicotinoylmorphine, morphine, and morphine-6-glucuronide.

Continuous high thoracic epidural administration of morphine with bupivacaine after thoracotomy.

BACKGROUND AND OBJECTIVES: The purpose of the study is to determine the ideal concentration of morphine when given with bupivacaine as a continuous high thoracic epidural infusion for postthoracotomy pain. METHODS: In a prospective study, 60 patients scheduled for thoracic surgery received a high thoracic epidural catheter. Postoperative analgesia was provided by a continuous epidural infusion for 3 days. The patients were randomly divided into two groups: group 1 (loading dose 1 mg morphine epidurally and continuous infusion of bupivacaine 0.75% + 0.2 mg/mL morphine at an infusion rate of 0.8 mL/hr); group 2 (loading dose 0.5 mg morphine epidurally and continuous infusion of bupivacaine 0.75% + 0.1 mg/mL morphine at an infusion rate of 0.8 mL/hr). RESULTS: The visual analog scales were not different at rest but with exercise in group 1 there was better pain relief than in group 2. The number of patients requiring supplementation of analgesia in group 2 (n = 42) was six times that of group 1 (n = 7). PaCO2 increased in both groups during the first postoperative day. There was no difference in the incidence of side effects between the two groups. CONCLUSIONS: Continuous high thoracic epidural administration 0.2 mg/mL morphine in bupivacaine 0.75% at an infusion rate of 0.8 mL/hr with a loading dose of 1 mg morphine is an effective dose for postthoracotomy pain relief in rest, and more important, during exercise.

High thoracic epidural sufentanil with bupivacaine: continuous infusion of high volume versus low volume.

The purpose of the study was to investigate whether continuous infusion of a high volume of a sufentanil/bupivacaine mixture at a high thoracic level improves the analgesic effect of the mixture, compared with a dose-equivalent continuous low-volume infusion. In a prospective, observer-blind study, 60 patients scheduled for thoracic surgery received a thoracic epidural catheter for 3 days. The patients were randomly assigned by lot to one of two groups: a low-volume (LV) group (bupivacaine 0.75% with sufentanil 4 micrograms/mL, 1.0-1.3 mL/h), or a high-volume (HV) group (bupivacaine 0.125% with sufentanil 0.7 microgram/mL, 6-8 mL/h). On the first postoperative day significantly more patients in the LV group needed one or more epidural bolus injections because they experienced pain at rest (P < 0.05). On the second and third postoperative days there were no differences in bolus injections. Significantly more patients in the HV group did not require an extra epidural bolus injection (P < 0.05). There were no differences in the number of patients experiencing pain at exercise or in the incidence of side effects. A difference was found between both groups in the mean preoperative PaCO2 value (P < 0.05) and also for the PaCO2 values on Day 1 versus the preoperative values within the group (P < 0.05). On the first postoperative day the analgesic effects of a sufentanil/bupivacaine mixture at a high thoracic epidural level can be improved when injected at a continuous high-volume rate compared with a dose-equivalent continuous low-volume rate. This is true for pain at rest; for pain at exercise, there were no differences.

Thoracic epidural bupivacaine plus sufentanil: high concentration/low volume versus low concentration/high volume.

BACKGROUND AND OBJECTIVES: To compare the postoperative analgesic and side effects of a continuous epidural infusion of bupivacaine with sufentanil: high concentration/low volume versus low concentration/high volume. METHODS: In a prospective study, 30 patients scheduled for thoracic surgery had a thoracic epidural catheter inserted. Postoperative analgesia was provided by a continuous epidural infusion for 3 days. The patients were randomly divided into two groups: the low volume (LV) group (1.5 to 2 mL per hour of a combination of bupivacaine 0.5% with sufentanil 4 micrograms.mL-1) and the high volume (HV) group (6 to 8 mL per hour of a combination of bupivacaine 0.125% with sufentanil 1 microgram.mL-1). RESULTS: The visual analogue scales were not different at rest or with exercise on days 1, 2, or 3. Supplemental analgesia by epidural catheter was necessary in half the patients in both groups. In two patients in the HV group and five patients in the LV group, a PaCO2 greater than mm Hg (7 kPa) was observed the first postoperative hour. Only on day 1 was the mean PaCO2 significantly increased in both groups (5.9 mm Hg [0.7] kPa in the LV group, and 6.0 mm Hg [0.4] kPa in the HV group) compared to the mean preoperative PaCO2 (5.1 mm Hg [0.5] kPa and 4.7 mm Hg [0.6] kPa). Between the groups there was no significant difference in PaCO2 at any time. CONCLUSIONS: With the thoracic epidural administration of bupivacaine and sufentanil for postoperative analgesia, the total dose is more important than the concentration or the volume of the solution.

Cardiac herniation after pneumonectomy.

Cardiac herniation is a rare, lethal complication of intrapericardial pneumonectomy demanding urgent treatment. It usually occurs within the first 24 h postoperatively. We present a patient with late cardiac herniation, 28 h postoperatively, where the electrocardiographic changes were evident several hours before the clinical picture became clear. After the diagnosis was made, the patient was treated surgically and survived.

Accidental overdose of epidural bupivacaine and sufentanil.

BACKGROUND AND OBJECTIVES: A case is described of an accidental high thoracic epidural infusion of 337.5 mg 0.75% bupivacaine and 180 micrograms sufentanil in less than 30 minutes. It occurred in a post-thoracotomy patient with lung cancer. RESULTS: Severe hypotension and an extensive sensory and motor block developed. Only a mild respiratory depression was seen. The patient recovered after treatment without adverse sequelae.

Coronary artery bypass grafting using two different anesthetic techniques: Part I: Hemodynamic results.

Hemodynamic changes were studied during two different anesthetic techniques in 54 patients undergoing coronary artery bypass grafting (CABG). All patients had normal to moderately impaired left ventricular function and were randomly assigned to two groups. In 27 patients, high thoracic epidural analgesia (TEA) with bupivacaine 0.375% plus sufentanil 1:200,000 (ie, 5 micrograms/mL) was used in combination with general anesthesia with midazolam/N2O; in the other 27 patients, general anesthesia (GA) with midazolam and sufentanil was used. After induction of epidural analgesia, heart rate and mean arterial pressure (MAP) decreased. Changes in cardiac index, systemic vascular resistance, and pulmonary capillary wedge pressure were not observed, whereas the stroke volume index increased significantly. After induction of intravenous anesthesia MAP decreased (20%) in both groups. During the pre-bypass period, metaraminol was used in 7 of 27 patients in the GA group and in 5 of 27 patients in the TEA group to treat hypotension. Inotopic drugs were used in 5 patients in the GA group and in none in the TEA group to treat a low CO. Ten GA patients and 4 TEA patients developed hypertension after sternal spread and the GA patients required more nitroprusside. Four GA patients developed electrocardiographic evidence of prebypass ischemia and, therefore, more nitroglycerin was needed for treating myocardial ischemia. More sodium nitroprusside was needed in the GA group during cardiopulmonary bypass (CPB) and the post-bypass period to treat hypertension with a high SVR. In conclusion, hemodynamic stability was more pronounced in the TEA than the GA group before and after CPB.

Coronary artery bypass grafting using two different anesthetic techniques: Part 2: Postoperative outcome.

The aim of the present investigation was to study the effects of intraoperative and postoperative epidural pain management during and after coronary artery bypass grafting (CABG) on the recovery time, postoperative pulmonary and cardiac parameters, visual analog scale (VAS) scores, and sedation scores (SS) compared with patients anesthetized with general anesthesia (GA) whose postoperative pain was relieved with intermittent intravenous (IV) administration of nicomorphine. Fifty-four patients were studied postoperatively after uncomplicated CABG. In the thoracic epidural analgesia (TEA) group (n = 27), intraoperative analgesia was based on high TEA in combination with GA. In the GA group (n = 27), IV anesthesia with high-dose sufentanil and midazolam was used. Postoperative pain management in the GA group consisted of intermittent IV administration of nicomorphine, 0.1 mg/kg every 6 hours, whereas for the TEA group continuous high TEA with 0.125% bupivacaine plus sufentanil, 1:1,000,000 (0.05 mL/cm body length/hr) was used. Patients in the TEA group awakened earlier (148 [34] minutes vs 335 [51] minutes), resumed spontaneous respiration earlier (326 [79] minutes vs 982 [52] minutes), and were extubated earlier (463 [79] minutes vs 1140 [58] minutes). VAS score, SS, and postoperative PaO2 were significantly (P less than or equal to 0.01) better in the TEA group. The incidence of tachycardia (15 vs 2 patients) and postoperative myocardial ischemia (12 vs 4 patients) was higher in the GA group. It is concluded that intraoperative and postoperative pain treatment with epidurally administered bupivacaine plus sufentanil improved the recovery time, as well as pulmonary and cardiac outcome after CABG, when compared with IV postoperative pain treatment after intraoperative GA with sufentanil and midazolam.

Coronary artery bypass grafting using two different anesthetic techniques: Part 3: Adrenergic responses.

Twenty patients were studied during and after coronary artery bypass grafting (CABG). The patients were randomly assigned to two groups. In 10 patients, intraoperative general anesthesia (GA) was based on a combination of intravenous (IV) sufentanil and midazolam. In 10 other patients, thoracic epidural analgesia (TEA) with 0.375% bupivacaine plus sufentanil, 1:200,000 (5 micrograms/mL), and intraoperative GA with midazolam/N2O were used. During the prebypass period, lower heart rates (HR), less variability in mean arterial pressure (MAP), and systemic vascular resistance (SVR) was accompanied by less variability in plasma norepinephrine (NE) concentrations in the TEA group. Although no differences were observed between the groups in perfusion pressure and the amount of vasoactive drugs used during the bypass period, variability in SVR was less in the TEA group. This was accompanied by less increase in NE and less variability in epinephrine (E) plasma concentrations. However, cortisol (Co) release was higher during this period in the TEA group. Weaning from bypass was accompanied by higher MAP and SVR in the TEA group at a lower HR, whereas no differences were observed in the E, NE, and Co plasma concentrations between the groups. During the first and second postoperative days, better pain relief and lower E and Co plasma concentrations were found in the TEA group. It can be concluded that better hemodynamic stability during the prebypass and bypass periods was accompanied by less E and NE release during these periods. Co release in the TEA group was higher during the bypass period. Weaning from bypass was characterized by better hemodynamics in the TEA group.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidural bupivacaine, sufentanil or the combination for post-thoracotomy pain.

Analgesia with epidural bupivacaine, sufentanil or the combination was studied in 50 patients who had undergone thoracotomy. During operation all patients received an initial dose of bupivacaine 0.5% with adrenaline 5 micrograms.ml-1 (5-10 ml) by thoracic epidural catheter. One hour later the patients were divided into three groups: the bupivacaine group (bupivacaine 0.125%), the sufentanil group (50 micrograms sufentanil in 60 ml normal saline) and the combination group (50 micrograms sufentanil in 60 ml bupivacaine 0.125%). Analgesia in the three groups was provided by a continuous epidural infusion (5-10 ml.h-1) for 3 days. The mean dose of bupivacaine was significantly higher (P less than 0.05) in the bupivacaine group (12.07 mg.h-1 (s.e.mean 0.97 mg.h-1)), compared with the combination group (9.82 mg.h-1 (s.e.mean 0.43 mg.h-1)). The mean dose of sufentanil in the sufentanil group was similar to the combination group (6.37 micrograms.h-1 (s.e.mean 0.23 micrograms.h-1) and 6.52 micrograms.h-1 (s.e.mean 0.28 micrograms.h-1), respectively. The pain scores on the inverse visual analogue scale of most patients in the bupivacaine group were unacceptably low. The sufentanil group had much better pain scores, but on exercise these patients experienced more pain than the combination group. The combination group had, overall, better pain scores. In the combination group, there were better respiratory results.

Pharmacokinetics of nicomorphine and its metabolites in man after epidural administration.

In ten patients who received an epidural injection of 15 mg of nicomorphine, the compound was relatively slowly released from the epidural space and was found in plasma for approximately 1.5 h. Nicomorphine is relatively slowly metabolized into 6-nicotinoylmorphine and morphine. The rate of release is patient-dependent. The relative AUC values are 15.3% for nicomorphine, 23.9% for 6-nicotinoylmorphine and 60.8% for morphine. The mean clinical effect lasts for 18.2 +/- 10.1 h.

Ventilatory function and continuous high thoracic epidural administration of bupivacaine with sufentanil intravenously or epidurally: a double-blind comparison.

Variables of ventilation were obtained preoperatively and during the first two postoperative days in 28 patients after thoracic surgery. All patients received 0.5% bupivacaine with epinephrine, 5 micrograms.ml-1 (5-10 ml), through an epidural catheter at the thoracic level supplemented by light general anesthesia. One hour after the initial dose of bupivacaine, patients were randomly allocated to one of two groups: an epidural (EP) sufentanil and an intravenous (IV) sufentanil group. Both groups received 0.125% bupivacaine via continuous epidural infusion postoperatively for three days. In addition, the EP group received 0.83 micrograms.ml-1 sufentanil added to the epidural infusion of 5-10 ml.hour-1, while the IV group received an identical dose of sufentanil via continuous intravenous infusion of 5-10 ml.hour-1. The ventilatory response to 5% CO2 was analyzed preoperatively and on postoperative Days 1 and 2. No significant depression in ventilatory response to CO2 could be detected by measurement of minute ventilation and mouth occlusion pressure at 100 milliseconds (P0.1). Pain measurement was assessed by blinded observers using the Inverse Visual Analog Scale, where 0 signifies most pain and 10 signifies least pain. The mean scores were above 7 in both groups and were attained at similar analgesic requirements. The incidence of side effects was not different. Only the initial mean sufentanil plasma levels in patients of the IV group were higher than those of the EP group. This study shows that the variables of ventilation were not affected by sufentanil administered via the epidural or the intravenous route, and that both techniques provided excellent pain relief when employed to supplement low-dose 0.125% bupivacaine epidurally.

Continuous high thoracic epidural administration of bupivacaine with sufentanil or nicomorphine for postoperative pain relief after thoracic surgery.

In a prospective study, 40 patients who had undergone thoracotomy for lung resection were investigated. During operation, all patients received intravenous anesthesics, halothane and an initial dose of bupivacaine 0.5% with epinephrine 5 micrograms.ml-1 (5 to 10 ml) by thoracic epidural catheter. One hour after the initial dose of bupivacaine 0.5% with epinephrine, patients were divided in two groups for analgesia, the sufentanil group (50 micrograms sufentanil in 60 ml bupivacaine 0.125%) or the nicomorphine group (3 mg nicomorphine in 60 ml bupivacaine 0.125%) by a continuous epidural infusion (5 to 10 ml.h-1) for three days. Cardiovascular differences between the sufentanil group and the nicomorphine group were not statistically significant per- or postoperatively. The minimum respiratory frequency on either Day 1, 2, or 3 was 12 breaths.min-1 in the sufentanil group, corresponding to a PaCO2 of 32 mmHg, and 11 breaths.min-1, corresponding to a PaCO2 of 41 mmHg in the nicomorphine group. On Day 1, the PaCO2 in the sufentanil group was significantly lower (p less than 0.01), but in both groups the PaCO2 on Day 1 was significantly higher than the preoperative value. An inverse visual analogue pain scale (0 to 10 IVAS) showed mean scores above 7.5 for all patients during the three days. Scoring pain relief during exercise showed a significant difference in favor of the sufentanil group on Days 1, 2, and 3 (p less than 0.0008). The mean plasma bupivacaine level doubled every day, 138 ng.ml-1 on Day 1, 290 ng.ml-1 on Day 2, and 596 ng.ml-1 on Day 3.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of continuous epidural analgesia with sufentanil and bupivacaine during and after thoracic surgery on the plasma cortisol concentration and pain relief.

The effect of continuous epidural analgesia with bupivacaine 0.125% and sufentanil 0.83 micrograms.ml-1 on the plasma cortisol concentration and postoperative pain relief was compared with that of intermittent intravenous peroperative and on-demand intramuscular postoperative analgesia with nicomorphine 0.2 mg.kg-1. The study was performed on two groups of ten patients for three consecutive days after thoracic surgery. In the epidural group, a better quality of analgesia was found as measured with the Inverse Linear Analgesia Scale (ILAS) (1 = severe pain, 10 = no pain) than in the group that received intramuscular analgesia. The mean ILAS scores in the epidural group were: day 1, 8.1 (SD, 1.26); day 2, 8.3 (SD, 0.87); day 3, 8.6 (SD, 0.71). The corresponding mean ILAS scores in the systemic group were 7.3 (SD, 1.38), 7.4 (SD, 1.16), and 7.6 (SD, 1.15). There was a significant difference between the ILAS scores for the two groups on all days (p less than 0.01). The mean plasma cortisol concentration was not significantly different between the groups during the period of investigation. In the epidural group, the highest measured mean cortisol concentration of 520.2 (SD, 266.4) nmol.L-1 was on day 2, whereas that in the systemic group was 738.3 (SD, 255.1) nmol.L-1 on day 1. The measured mean plasma cortisol concentration was found to exceed normal limits (150-700 nmol.L-1) only in the systemic group and only on day 1.

Migration of thoracic epidural catheters. Three methods for evaluation of catheter position in the thoracic epidural space.

Migration of thoracic epidural catheters was evaluated in 25 patients by three methods either after placement of the catheter or immediately after surgery. The first method was the determination of the depth of the catheter from the skin, the second the determination of the level of sensory blockade which resulted from a test dose of a local anesthetic agent, while the third consisted of radiological visualisation of the catheter tip in the epidural space with radiopaque dye. The evaluations were repeated on the third or fourth day after operation. We observed an inward movement of the catheter in 56% of the patients instead of the expected outward movement. This inward movement was accompanied by a higher level of sensory blockade. No relationship with radiological visualisation was found.

Spread of radiopaque dye in the thoracic epidural space.

A radiological study was performed in 23 patients to look for the position of thoracic epidural catheters and the spread of the contrast medium iohexol 300 mg/ml and 180 mg/ml when used in volumes of 3 and 8 ml. The dye was injected through the epidural catheter just after thoracic surgery. The spread of the dye showed no relation to the injected volume or the sensory spread after 2% lignocaine 3 ml. In three cases no contrast could be seen on the x-ray, and in two the radiopaque dye was found just outside the epidural space. No relationship between the spread of the dye and the sensory blockade was found, but the position of the epidural catheter should be checked radiographically when the epidural route is to be used for long-term pain relief.

Anaesthesia for bullectomy. A technique with spontaneous ventilation and extradural blockade.

A patient with severe bullous emphysema in whom one bulla occupied more than 25% of the hemithorax, with a shift of the mediastinum to the opposite side, was anaesthetised for bullectomy with a combination of intravenous gamma-hydroxybutyric acid and a high thoracic extradural catheter technique. During the operation the patient breathed 100% oxygen through a double-lumen endobronchial tube in the lateral thoracotomy position. Extradural analgesia during the operation was provided by bupivacaine 0.25%, with adrenaline 1:200 000 and, postoperatively, with nicomorphine diluted in dextrose 5%. The advantages of this technique are described.