Regional analgesia in early active labour: combined spinal epidural vs. epidural

Conventional calculation of joint power is not effective in order to assess translational motions of human body. Two new approaches were developed in this study to estimate translational mechanical outputs from individual joints. They were applied to the analysis of vertical jump motions of six male subjects. In both cases, body of subjects were modeled with a four mass-points system model, and joints were regarded as motion generators. In one approach, increase of vertical component of ground reaction force (GRF) was decomposed into push-off force of three joints (ankle, knee, and hip joints). This procedure gave an estimation of impulse exerted per leg, as 83-92 N s (95% confidential interval) for squat jump, which was similar to half of the impulse provided to mass center of the body calculated from GRF, 82-88 N s. In the other approach, amount of the power exerted by each joint vertically was estimated by calculating the scalar product of joint reaction force and relative velocity vectors of adjacent segments. This approach gave estimation of vertical work provision per leg, as 201-226 and 141-181 J for squat and counter movement jumps, which were not so different from half of the work provided to mass center of the body calculated from GRF, 209-227 and 137-175 J, respectively. As these approaches make it possible to calculate translational mechanical outputs specifically, they are useful and consistent concerning the analysis of translational motion of human body.     

Perioperative myocardial ischaemia in patients undergoing transurethral surgery: a pilot study comparing general with spinal anaesthesia

We have studied the incidence and duration of perioperative myocardial ischaemia using ambulatory ECG monitoring in 100 patients undergoing transurethral surgery, who were allocated randomly to receive either general or spinal anaesthesia. The overall incidence of myocardial ischaemia increased from 18% to 26% between the preoperative and postoperative periods. Patients with ischaemic heart disease had a significantly greater incidence of myocardial ischaemia after operation than patients without known ischaemic heart disease (P < 0.05). There was an increase in both the incidence and duration of myocardial ischaemia after operation with both anaesthetic techniques, but no significant difference between the two.     

Caudal clonidine and bupivacaine for combined epidural and general anaesthesia in children

BACKGROUND: Clonidine produces analgesia by actions on alpha 2-adrenoceptors and enhances both sensory and motor blockade from epidural injection of local anaesthetics. Low-dose clonidine has been used so far for caudal injection in children. Our aim was to study the perioperative effects of high-dose caudal clonidine when added to low concentration of bupivacaine for combined epidural and general anaesthesia in children. METHODS: After induction of general anaesthesia caudal block was performed either with 1 ml.kg-1 bupivacaine 0.175% with the addition of clonidine 5 micrograms.kg-1 (n = 20), or with 1 ml.kg-1 bupivacaine 0.175% (n = 20). The intraoperative anaesthetic requirements, the perioperative haemodynamic effects, respiratory rate, sedation score, postoperative pain scores and side effects were assessed by a blinded observer. A patient-controlled analgesia system was used for postoperative pain relief. The quality of postoperative pain relief was assessed using Smiley's pain analogue scale. RESULTS: Intraoperative haemodynamic responses did not differ between the groups. However, during emergence from general anaesthesia children in the clonidine group had significantly lower heart rates and blood pressure compared to children in the control group. In addition, heart rates and blood pressures were also lower in the clonidine group in the early postoperative period (P < 0.05). Postoperative analgesia was significantly better in the clonidine group as evidenced by the total number of requests (3 vs 12, P < 0.05) and the total amount of tramadol (20.5 mg vs 72.8 mg, P < 0.05) administered. The duration of the caudal analgesia was significantly longer in the clonidine group (20.9 +/- 7.4 h vs 14.4 +/- 10.9 h, P < 0.05). CONCLUSION: Our results suggest that caudal clonidine 5 micrograms.kg-1 enhances and prolongs caudal blockade with bupivacaine (1.175% in children. It also blocks sympathoadrenergic responses during emergence from anaesthesia. Sedation and cardiovascular effects are observed up to 3 h into the postoperative period.     

Adrenaline, cyclic AMP and potassium during general anaesthesia with and without epidural analgesia

Twenty patients undergoing abdominal surgery under general anaesthesia were studied to determine whether beta 2-adrenergic receptor sensitivity and adrenaline-induced hypokalaemia are related to preceding adrenergic stress. Half of the patients were given epidural analgesia with bupivacaine-adrenaline before starting surgery and then a booster dose after 60 min of surgery. The others were given only the epidural dose of bupivacaine-adrenaline at 60 min. Despite marked increases in the plasma adrenaline concentration after the intra-operative epidural dose, there was no decrease in the serum potassium concentration in either group. In the patients who received only the 60 min dose, the plasma adrenaline concentrations increased more, but the plasma level of cyclic AMP (a marker for beta 2-stimulation) increased similarly, which suggests that beta 2-adrenoceptor responsiveness was somewhat reduced. After the intraoperative bupivacaine-adrenaline, the T wave amplitude decreased, but neither U waves nor tachycardia developed. In conclusion, adrenergic stimulation during surgery does not decrease the serum potassium concentration, regardless of whether the surgical stress response has been modified by epidural analgesia. This lack of a hypokalaemic effect might be partly due to reduced responsiveness of beta 2-adrenoceptors to adrenaline.     

The effect of clonidine on intra-operative requirements of fentanyl during combined epidural/general anaesthesia

The study evaluates the analgesic effects of epidural clonidine in patients undergoing abdominal hysterectomy under combined epidural/general anaesthesia. Forty ASA 1-2 patients were divided into two groups who received epidurally either clonidine 300 micrograms (group 1) or placebo (group 2). Anaesthesia was maintained with oxygen/nitrous oxide, a midazolam infusion, vecuronium, and boluses of fentanyl 100 micrograms administered as needed to maintain cardiovascular stability. The mean (SD) intraoperative fentanyl requirements were 2.05 (0.18) and 3.66 (0.3) micrograms.kg-1.h-1 for groups 1 and 2 respectively (p < 0.001). Patients in Group 1 had a lower heart rate after tracheal intubation and surgical incision (p < 0.02). In the recovery room, pain intensity was lower in group 1 (p < 0.003) and the mean (SD) time until analgesia request was increased from 48.5 (8.4) min in group 2 to 235.7 (33.2) min in group 1 (p < 0.001). Our results demonstrate that epidural clonidine produces decreased fentanyl requirements, improved cardiovascular stability, reduced pain intensity and effective postoperative analgesia in the recovery room.     

Perioperative respiratory events in smokers and nonsmokers undergoing general anaesthesia

BACKGROUND: The prevalence of respiratory diseases in smokers and nonsmokers and the incidence of perioperative respiratory events (PREs) were investigated for patients undergoing general anaesthesia. The aim was to quantify well-known problems and to identify possible new associations between smoking and PREs. METHODS: From July 1992 to December 1994, risk factors, demographic data, and PREs were documented by an automatically readable anaesthetic record (ARAR). PREs were used as defined by the German Society of Anaesthesiology and Intensive Care. RESULTS: Of 26961 subsequent anaesthesias in adults, 7122 (26.4%) were performed in smokers with a prevalence of chronic bronchitis of 23.3% (4.8% in nonsmokers). 1573 PREs occurred in 1397 (5.2%) of all anaesthetics. 459 events concerned intubation problems and problems in technical airway management. 1114 specific respiratory events (SPREs) like re-intubation, laryngospasm, bronchospasm, aspiration, hypoventilation/hypoxaemia and others had a total incidence of 5.5% in smokers and 3.1% in nonsmokers. The relative risk (RR) of SPREs was 1.8 in all smokers, 2.3 in young (16-39 years) smokers, and 6.3 in obese young smokers. The RR of perioperative bronchospasm was 25.7 in young smokers with chronic bronchitis. CONCLUSION: The impact of smoking on perioperative respiratory problems should make anaesthetists take this widespread preoperative condition seriously, particularly in young adults. The presented method of incident reporting (based on a national classification) could contribute to future research in anaesthetic epidemiology.     

Intraoperative intravenous ketamine in combination with epidural analgesia: postoperative analgesia after renal surgery

We designed this double-blinded, randomized, controlled study to evaluate the effect of small-dose ketamine IV in combination with epidural morphine and bupivacaine on postoperative pain after renal surgery. An epidural catheter was inserted, and the administration of morphine and bupivacaine was started before surgery. Forty patients were assigned to one of two groups (ketamine or control). The ketamine group was administered a ketamine bolus and infusion during surgery. The median visual analog pain scale (VAS) scores at rest were significantly lower in the ketamine group during the first 6 h (P < 0.01). VAS pain scores on coughing were also significantly lower in the ketamine group (P < 0.01). Cumulative postoperative total analgesic consumption was less in the ketamine group on Days 1 and 2 (P < 0.001). The first analgesic demand time was shorter in the control group (9.2 +/- 11.5 min) than in the ketamine group (22.3 +/- 17.1 min) (P < 0.0001). The incidence of nausea and pruritus was more frequent in the control group (P < 0.05). In conclusion, postoperative analgesia was more effective when spinal cord and brain sensitization were blocked by a combination of epidural morphine/bupivacaine and IV ketamine. IMPLICATIONS: Renal nociception conducted multisegmentally by both the spinal nerves (T10 to L1) and the vagus nerve cannot be blocked by epidural analgesia alone. We demonstrated that IV ketamine had an improved analgesic or opioid-sparing effect when it was combined with epidural bupivacaine and morphine after renal surgery.     

Pre-emptive analgesia using local anaesthesia: a study in bilaterally symmetrical surgery

Two studies were carried out in patients undergoing bilaterally symmetrical lower third molar surgery under general anaesthesia. In the first study observations were carried out in 40 patients, using McGill pain questionnaires and visual analogue scales (VAS), to assess the variation in pain intensity between the two sides in each individual on the morning after surgery. The within-patient variation in pain intensity indicated that a sample size exceeding 30 was required to show a difference of more than 10 mm on the VAS and achieve a power of 90% at the 5% level of significance. The second study was carried out to determine if local anaesthesia administered before rather than after tooth removal rendered any benefit. Each of the 38 patients acted as their own control; one side was allocated randomly to receive the local anaesthetic before operation and the other side after operation. The difference in pain between the pretreated and post-treated sides in each individual was assessed using a McGill pain questionnaire on the morning after surgery in addition to two VAS (one for each operation side) after operation, at 6 h, 1 and 6 days after surgery. There were no significant differences in pain at any time using any of the above methods.     

Thoracic epidural analgesia in aortocoronary bypass surgery. II: Effects on the endocrine metabolic response

Thoracic epidural analgesia (TEA) may offer haemodynamic benefits for patients with coronary heart disease going through major surgery. This may-in part-be secondary to an effect on the endocrine and metabolic response to surgery. We therefore investigated the effect of TEA on the endocrine metabolic response to aortocoronary bypass surgery (ACBS). Thirty male patients (age < 65 years, ejection fraction > 0.5) were randomized into 3 groups; the HF group receiving a high dose fentanyl (55 micrograms.kg-1) anaesthesia, the HF+TEA group with the same fentanyl dose+TEA with 10 ml bupivacain 5 mg.ml-1, followed by 4 ml every hour, and the LF+TEA group receiving fentanyl 15 micrograms.kg-1 + TEA. Adrenalin, noradrenalin, systemic vascular resistance (SVR), glucose, cortisol, lactate and free fatty acids were followed during the operation and for 20 h postoperatively. A significant increase in adrenalin, noradrenalin and SVR was found in the HF group whereas this increase was blocked in both epidural groups. An increase in glucose and cortisol was noticed in all groups, but the increase was delayed in the epidural groups. Our results suggest that a more effective blockade of the stress response during ACBS is obtained when TEA is added to general anaesthesia than with high dose fentanyl anaesthesia alone.     

Safety and efficacy of spinal vs general anaesthesia in bone marrow harvesting

In cases of completed middle cerebral artery territory stroke, prognosis is very poor and the clinical course is characterised by a rapid decline in consciousness and signs of herniation 2-4 days after the onset of symptoms due to a space-occupying mass. Failure of conservative therapy is the rule, and herniation is the usual cause of death, occurring in almost 80 per cent of cases. Recently published results have suggested that hemicraniectomy may improve survival in patients with massive hemisphericstroke, decreasing mortality to less than 35 per cent. The article presents what is probably the first case to be reported in Sweden, where hemicraniectomy was performed on a 45-year-old woman with right hemispheric completed middle cerebral artery infarction.     

The effect of i.v. enalaprilat in chronically treated hypertensive patients during cardiac surgery

In areas where hepatitis B virus (HBV) is prevalent, HBV carriers negative for hepatitis B surface antigen (HbsAg) by enzyme-linked immunosorbent assay (ELISA) have been reported. Moreover, even after screening donor blood for HbsAg and hepatitis B core antibody (HBcAb), post-transfusion hepatitis B continues to occur, though with a decreasing frequency. Therefore, screening tests far more sensitive for detecting HBsAg than those currently available are needed. We developed a highly sensitive method for HBsAg detection. It is based on the recognition of peroxidase activity through measuring the formation of stable nitroxide radical with electron spin resonance (ESR) spectroscopy in the presence of hydrogen peroxide, p-acetamidophenol (p-AP), and 4-hydrazonomethyl-1-hydroxy-2,2,5,5,-tetramethyl-3-imidazoline-3-o xide (HHTIO). A cut-off value was established by testing of 186 healthy adults and 50 HBsAg-positive individuals. The signal to noise (S/N) ratio of less than 1.488 obtained by ESR spectroscopy was considered to be negative and more than 2.181, positive. The p-AP/HHTIO method was found to be 10 times more sensitive than the standard ELISA and reproducibility was excellent. Additional investigations were made on the HBsAg levels in the serum from 26 healthy subjects, in whom cut-off index levels on ELISA were negative but relatively high (range: 0.6 to 1.0); and on 15 patients with non B non C hepatitis. Three of 26 cases and 3 of 15 with non B non C hepatitis were judged to be HBsAg positive. Of these, 5 were found to be positive for HBV DNA by polymerase chain reaction (PCR). It was shown in this study that the p-AP/HHTIO method is practical and useful in screening HBV carriers because of the sensitivity in HBsAg detection, which is comparable to PCR analysis.     

Effects of thoracic vs. lumbar epidural anaesthesia on systemic haemodynamics and coronary circulation in sevoflurane anaesthetized dogs

BACKGROUND: Although many investigators reported changes in coronary circulation during thoracic epidural anaesthesia (TEA), no previous studies have attempted to compare it with lumbar epidural anaesthesia (LEA) concerning coronary circulation. Our aim was to compare effects of TEA on systemic haemodynamics and coronary circulation with those of LEA in anaesthetized dogs. METHODS: In dogs receiving 1.5% sevoflurane, 2% lidocaine (0.1 ml kg-1) was injected into the epidural space via an epidural catheter inserted at either the T7-T8 (TEA group, n = 8) or L5-L6 (LEA group, n = 8) interspace, and the same dose was repeated again 30 min later. RESULTS: Heart rate and maximum left ventricular dP/dt decreased in the TEA group but were unchanged in the LEA group. Decreases in mean arterial pressure were found for both groups, and they were more substantial in the TEA than in the LEA group. Decreases in left ventricular minute work index were found for both groups, and they tended to be more substantial in the TEA than in the LEA group. Coronary perfusion pressure and blood flow decreased in both groups. Calculated coronary vascular resistance increased in the TEA group but was unchanged in the LEA group. CONCLUSION: The most significant difference between TEA and LEA concerning coronary circulation was characterized by an increase in coronary vascular resistance in the TEA group, which was not present in the LEA group. The increase in coronary vascular resistance caused by TEA may be explained by a coronary vasoconstriction caused by a lower myocardial oxygen demand.     

Value of combined spinal and epidural anesthesia in the management of peroperative analgesia in prosthetic surgery of the lower limb. Prospective study of 68 cases

PURPOSE OF THE STUDY: Efficient peri-operative analgesia is more comfortable, allows earlier mobilisation and better functional results for lower limb arthroplasties. We report our 60 cases prospective study of combined spinal and epidural anesthesia, and expose interests of this technique to control peri-operative pain. MATERIALS: From 1994 to 1995, 60 patients ASA class 1 were operated: 45 total hip replacement (THR), 15 total knee replacement (TKR). The average age was sixty five years (range thirty nine to eighty five years). Combined spinal and epidural anesthesia was performed in every case. METHODS: In lateral decubitus position, a translucent 25 Gauge needle was introduced in L2-L3 interspace. In a first time spinal anesthesia was made with 20 mg Bupivacaine. In a second time, a lumbar epidural catheter was inserted. All patients received an epidural post-operative analgesia with 4 mg Morphine once a day during two days and intravenous Paracetamol. Visual analogue scale (0 to 10) (VAS) were recorded after the third post operative hour and every twelve hours. During this period satisfaction mark was also recorded (1 to 3). RESULTS: We didn't observe any case of respiratory depression or infection with the epidural catheter. We observed 10 cases of pruritus (one needed to stop protocol) and 18 urinary retentions. Six uretral catheters were necessary; we had one case of pyelonephritis (escherichia coli). The first micturition was obtained 13.5 hours after the end of surgery. For the fifty nine remaining patients, visual analogue scale was always inferior or equal to 2/10 and the satisfaction mark to 1/3. DISCUSSION: Different techniques allow peri-operative analgesia, but a few are efficient during the first two days. Plexus nerve blocks are simple and reliable but post-operative anesthesia is short (inferior to 15 hours). Intravenous morphine controlled by patients themselves with programmed display needs expensive and sophisticated material. The principal risk is respiratory depression. Epidural morphine has a lower respiratory depression risk, but needs a heavier technique. The principal problems is higher incidence of urinary side effects. Epidural anesthesia might tend to show a greater efficacity with the best visual analogue scale and satisfaction mark. CONCLUSION: The results indicate that combined spinal and epidural anesthesia for the management of peri-operative pain provide an excellent pain control with a daily morphine injection. For lower limb arthroplasties, visual analogue scale is always inferior or equal to 2 and satisfaction mark equal to 1.     

Attenuation of the haemodynamic responses to noxious stimuli in patients undergoing cataract surgery. A comparison of magnesium sulphate, esmolol, lignocaine, nitroglycerine and placebo given i.v. with induction of anaesthesia

A study was conducted on 100 middle-aged to elderly patients (n = 52, healthy; n = 48, suffering from either diabetes, hypertension, ischaemic heart disease or a combination of these diseases) undergoing cataract extraction to assess the effects of laryngoscopy and tracheal intubation, anaesthesia and surgery, eye bandaging and tracheal extubation, saline (control), magnesium sulphate 40 mg kg-1, esmolol 4.0 mg kg-1, lignocaine 1.5 mg kg-1 and glyceryl trinitrate 7.5 micrograms kg-1 given i.v. at induction of anaesthesia on heart rate (HR), blood pressure (BP), rate-pressure product (RPP) and pressure-rate quotient (PRQ). Anaesthesia was standardized. Haemodynamic responses and requirements for atropine, ephedrine and labetalol to maintain HR and BP during surgery were similar in healthy and diseased patients, and in the test drug groups. Differences produced by the test drugs were evident until 5 min following intubation. Esmolol prevented rises in HR and RPP. Glyceryl trinitrate prevented a rise in BP, but was associated with tachycardia and a fall in PRQ to < 1.0. Magnesium sulphate and lignocaine did not prevent responses to laryngoscopy and tracheal intubation, and were associated with rises in RPP. Application of the eye dressing and tracheal extubation at the end of surgery each caused significant increases in HR, BP and RPP in all groups.     

Complications during and after surgery and childbirth where spinal or epidural analgesia is used. Guidelines for safe practice

When complications and neurological sequelae occur during a spinal or epidural anaesthetic the causes are clearly related to the procedures in the following cases: severe haemodynamic or respiratory derangement, documented needle trauma of nerve fibres, intraspinal haematoma in anticoagulated or heparinized patients, and epidural infection where an infected epidural catheter entry site is documented. A number of well documented cases have been published in which surgery or patient-related pathology were primary causes of "typical" spinal or epidural neurological complications. These emphasize the importance of searching for other risk factors of neurological sequelae after surgery or child birth in cases where there is no obvious deviation from the normal epidural or spinal procedures. Increased focus on the infrequent, but serious complications of these essentially very safe techniques for surgical anaesthesia and pain relief should serve to increase our vigilance, but should not reduce the application of spinal and epidural analgesia. Guidelines are offered for the effective and safe practice of spinal and epidural anaesthesia and pain relief: adequate supervision of trainee anaesthetists, vigilant monitoring for early detection and handling of complications, and trained nurses on surgical wards to monitor and handle patients during epidural analgesia are important. Sufficient readiness for urgent handling of the very rare, but devastating complications of intraspinal bleeding or infection is an absolute necessity.     

Inhibition of naloxone-precipitated withdrawal jumping by i.c.v. and i.t. administration of saline in morphine-dependent mice

In morphine-dependent mice, s.c. and i.t. administered naloxone produced withdrawal jumping (ED50 values were i.t. = s.c.) but i.c.v. administered naloxone failed to produce dose-dependent jumping. Peak times of jumping were earliest after i.t. administration of naloxone among the three administration routes. These results suggested that the spinal site was more sensitive to naloxone than the supraspinal site. Concomitant administration of naloxone i.c.v. and i.t. did not precipitate jumping. It was found that i.c.v. and i.t. injections of saline inhibited withdrawal jumping precipitated by s.c. administered naloxone and that the i.c.v. effect was more profound than the i.t. effect. I.c.v. injection of saline also delayed the peak time of withdrawal jumping precipitated by s.c. administered naloxone. These inhibitory effects of the injection procedures may explain the difficulty of i.c.v. administered naloxone and concomitant i.c.v. + i.t. administered naloxone to precipitate jumping, and may explain the difference in the ED50 values of naloxone and the time courses of jumping.     

Comparing i.v. and non-i.v. cocaine users. Characteristics of a sample of cocaine users seeking to participate in research

Psychiatric disorders were studied in an epidemiological and representative sample of 1964 pupils attending the first to ninth grade in various types of schools in the Canton of Zürich, Switzerland. Using a two-stage procedure, parents were asked to respond to a standardized behaviour problem checklist in the screening phase. In the second stage, structured interviews were performed with 399 parents representing both screen positive and control children. DSM-III-R diagnoses were derived from the interviews. The total prevalence figure for any disorder amounted to 22.5%. Prevalence rates were influenced by the multi-screen procedure. Among various correlates, sex, nationality, age and residence were to some extent significant. Comorbid disorders were present in 12.5% of the subjects.     

Safety and cost of rapid i.v. injection of famotidine in critically ill patients

The safety and cost of famotidine in intensive care patients given the drug by rapid i.v. injection or slow i.v. infusion were studied. All patients admitted to the medical-coronary care and surgical intensive care units (ICUs) at a university teaching hospital over a two-month period who had orders for at least one dose of famotidine injection for any indication were randomly assigned to receive the drug by rapid i.v. injection or slow i.v. infusion via volumetric chamber. Data on patient demographics, drug administration time, adverse effects, cardiovascular variables, and costs (including drug acquisition, supply, and nursing personnel costs) were collected prospectively. Fifty-three patients received famotidine by i.v. injection (a total of 1041 doses) and 52 by i.v. infusion (1006 doses). The mean +/- S.D. duration of famotidine administration was 44 +/- 12 seconds in the i.v.-injection group and 19 +/- 5 minutes in the i.v.-infusion group. Adverse effects possibly related to famotidine occurred in three injection-group patients and two infusion-group patients. No significant difference between the groups in cardiovascular variables (mean arterial pressure, heart rate, and respiratory rate) was noted. Cost savings for the injection group relative to the infusion group totaled $2886 for the two-month study period. Half of the savings came from reduced supply costs and half from reduced personnel costs. The annualized savings to the institution would be about $17,300. Rapid i.v. injection of famotidine appeared to be as safe in ICU patients as giving the drug by slow i.v. infusion and was less costly.     

Red cell aplasia caused by parvovirus B19 in AIDS: use of i.v. immunoglobulin

We describe the case of a 34-year-old man with AIDS who developed severe anemia due to chronic pure red cell aplasia (PRCA) caused by parvovirus B19. Following initial treatment with an infusion of intravenous immunoglobulin (IVIg), 1 g/kg, PRCA resolved, but there was a recurrence of severe anemia in 3 months. Retreatment with 2 g/kg IVIg over 2 days resulted in normalization of hemoglobin and a significantly longer remission duration. Two doses of 0.4 g/kg IVIg q 4 wk failed to prevent a relapse of PRCA in our patient. The dose and schedule of IVIg in the treatment of PRCA caused by parvovirus B19 in AIDS requires further definition.