Showing papers in "Acta Anaesthesiologica Scandinavica in 1999"

Chronic pain after thoracic surgery: a follow-up study.

Abstract: Background: The incidence of long-term post-thoracotomy pain is reported to be up to 67%. A relationship between the severity of acute postoperative pain and the development of chronic post-thoracotomy pain has been suggested. Methods: Patients scheduled for elective thoracotomy were interviewed before and one week after surgery to find out if they had pain before surgery and how much pain they experienced postoperatively. The amount of analgesics the patients were given were registered during the first 5 postoperative days. The patients were interviewed by letter 3, 6 and 12 months after surgery to find out if they still had pain due to surgery and to what extent this pain interfered with their daily activities. Results: One hundred and ten patients entered the study. Information about the complete study period was obtained from 67 patients. The incidence of chronic post-thoracotomy pain was 80% at 3 months, 75% at 6 months and 61% one year after surgery. The incidence of severe pain was 3–5%. Chronic post-thoracotomy pain interfered with the patient’s normal daily life in more than half of the patients. High consumption of analgesics during the first postoperative week was associated with a higher risk of chronic post-thoracotomy pain. Conclusion: A significant proportion of patients undergoing thoracotomies will suffer from chronic pain. Surgeons and anaesthetists should be aware of this fact and they should look for effective means of preventing and treating this pain syndrome.

Pain--an overview.

Abstract: The neuromatrix theory of pain proposes that pain is a multidimensional experience produced by characteristic "neurosignature" patterns of nerve impulses generated by a widely distributed neural network--the "body-self neuromatrix"--in the brain. These neurosignature patterns may be triggered by sensory inputs, but they may also be generated independently of them. Pains that are evoked by noxious sensory inputs have been meticulously investigated by neuroscientists, and their sensory transmission mechanisms are generally well understood. In contrast, chronic pain syndromes, which are often characterized by severe pain associated with little or no discernible injury or pathology, remain a mystery. The neuromatrix theory of pain, however, provides a new conceptual framework that is consistent with recent clinical evidence. It proposes that the output patterns of the neuromatrix activate perceptual, homeostatic and behavioral programs after injury or pathology, or as a result of multiple other inputs that act on the neuromatrix. Pain, then, is produced by the output of a widely distributed neural network in the brain rather than directly by sensory input evoked by injury, inflammation or other pathology. The neuromatrix, which is genetically determined and modified by sensory experience, is the primary mechanism that generates the neural pattern that produces pain. Its output pattern is determined by multiple influences, of which the somatic sensory input is only a part, that converge on the neuromatrix.

The Role of Nitric Oxide in Sepsis--An Overview

Abstract: Nitric oxide (NO) is normally produced in the endothelium by the constitutive isoform of the NO synthase. This physiological production of NO is important for blood pressure regulation and blood flow distribution. Several lines of evidence suggest that a hyperproduction of NO by the inducible form of NO synthase (iNOS) may contribute to the hypotension, cardiodepression and vascular hyporeactivity in septic shock. Lipopolysaccarides and cytokines, such as tumor necrosis factor, interleukin-1 and interferon-gamma, have been shown to induce iNOS in the endothelium, vascular smooth muscle cells, macrophages and different parenchymal cells. Treatment with inhibitors of NO synthesis has been shown to improve hemodynamic variables and survival in several animal models of septic shock. In human septic shock, inhibition of NO synthesis has been shown to alter hemodynamic variables in short-term studies, but it is uncertain whether this treatment has beneficial long-term effects. The aim of this review is to give an overview of the physiological role of NO and to discuss the role of NO in sepsis and the potential therapeutic implications of NO as a target in treatment of human septic shock. A main new aspect of this review is a critical discussion of previous reports measuring plasma nitrite/nitrate during septic shock and an evaluation of the validity of interpreting these data as evidence for a hyperproduction of NO. This review also emphasizes that many septic patients have preexisting endothelial dysfunction and lung diseases, which may contribute to adverse effects by systemic inhibition of NO synthesis. Another new aspect of the present review is a focus on the lack of direct evidence of iNOS expression in human septic shock.

Positive end-expiratory pressure prevents atelectasis during general anaesthesia even in the presence of a high inspired oxygen concentration.

Abstract: Positve end-expiratory pressure prevents atelectasis during general anaesthesia even in the presence of a high inspired oxygen concentration

The role of psychological factors in chronic pain.

Abstract: The traditional view conceptualizes pain as being directly associated with the extent of physical pathology. The observations that there are a number of patients who report pain in the absence of physical pathology, the converse, asymptomatic individuals who evidence objective physical pathology, the inconsistency in response of patients with identical diagnoses, and the low association between impairments and disability suggest that factors other than physical pathology contribute to the reports of pain. The role of behavioral, cognitive, and affective factors have each been shown to have direct effects on the report of pain, adaptation, and response to treatment, as well as indirect effects by influencing sympathetic nervous system and neurochemical factors associated with nociception. The direct and indirect effects of behavioral (operant), cognitive, and affective factors in chronic pain are described.

Single‐injection paravertebral block compared to general anaesthesia in breast surgery

Abstract: Background: Breast surgery is frequently associated with postoperative nausea, vomiting, pain and painful restricted movement. Paravertebral block may be an alternative to general anaesthesia for this type of surgery. We studied the single-injection paravertebral block at the level of T4 and report a comparison of single-injection paravertebral block to general anaesthesia for breast surgery. Methods: After written informed consent was obtained, 86 patients were enrolled in this prospective study. Forty-four women were randomly allocated to receive a single-injection paravertebral block at the level of T4, while 42 women received general anaesthesia. The surgical procedures varied from lumpectomy (wide local excision of a tumour) to modified radical mastectomy with axillary dissection. The block was performed according to the guidelines described by Eason and Wyatt using 0.3 ml · kg−1 (maximum dose 150 mg) of bupivacaine 0.5%. The skin and the underlying tissues were infiltrated with local anaesthetic solution two fingers (about 3 cm) from the anatomical midline and level with the cephalad end of the vertebral spine. Results: Time for performance of blocks lasted from 4 to 9 min. Recovery from anaesthesia or sedation was shortened, while postoperative pain scores (VAS), the incidence of vomiting and the requirement for analgesics were lower in the paravertebral group. Less painful restricted movement was observed in the paravertebral block group. Paravertebral block was inadequate in 6.8% of patients. Epidural spread with paraparaesis and Horner triad was assumed in one patient. Conclusion: Single-injection paravertebral block at the level of T4 represents a suitable alternative to general anaesthesia in women undergoing breast surgery.

EEG bispectral index monitoring in sevoflurane or propofol anaesthesia: analysis of direct costs and immediate recovery.

Abstract: Background: Recent studies have suggested that electroencephalogram (EEG) bispectral index (BIS) monitoring can improve recovery after anaesthesia and save money by shortening patients’ postoperative stay. We wanted to evaluate the direct costs of BIS monitoring and to measure immediate recovery after anaesthesia in patients with or without BIS monitoring. Methods: Eighty patients undergoing gynaecological surgery were studied. At first, 40 patients were randomized to receive either propofol or sevoflurane anaesthesia. In these patients, BIS was collected but the information was not displayed. Thereafter, the anaesthesiologists were trained to follow and understand the BIS information, and 40 patients were anaesthetized with aid of the monitoring. Recovery times were measured by a study coordinator. Drug consumption was calculated. Results: BIS monitoring improved the immediate recovery after propofol anaesthesia, while no differences were seen in patients receiving sevoflurane. The consumption of both propofol and sevoflurane decreased significantly (29% and 40%, respectively). BIS monitoring increased direct costs in these patients; the break-even times (704 min for propofol and 282 min for sevoflurane) were not reached. Conclusion: BIS monitoring decreased the consumption of both propofol and sevoflurane and hastened the immediate recovery after propofol anaesthesia. Detailed cost analysis showed that the monitoring increased direct costs of anaesthesia treatment in these patients, mainly due to the price of special EEG electrodes used for relatively short anaesthesias.

Lateral infraclavicular plexus block vs. axillary block for hand and forearm surgery.

Abstract: Background: In the last few years infraclavicular plexus block has become a method of increasing interest. However, this block has been associated with high complication incidences and without advantage in the quality of blockade over the axillary approach. We prospectively studied 40 patients (ASA I–III) undergoing surgery of the forearm and hand, and investigated the performance of the lateral infraclavicular plexus block against an axillary paravascular block to evaluate the success rate as well as the extent and quality of blockade. Methods: Patients were randomized into two groups: group I (lateral infraclavicular approach; n=20) and group A (axillary approach; n=20). The lateral infraclavicular approach is a technique with the coracoid process (CP) as landmark. Alone the sagittal plane, the needle is inserted until contact with the CP. The needle is then withdrawn 2–3 mm and reinserted directly under the CP, until it contacts the brachial plexus sheath. Plexus blockade was performed using 40 ml of mepivacaine 1%. Quality of sensory and motor block was recorded selectively for each nerve distribution at close intervals for 6 h. Results: Successful block according to Vester-Andersen’s criteria was achieved in 100% of group I and 85% of group A. In group I, a pronounced sensory and motor blockade of the musculocutaneous nerve was observed, while patients of group A had a weak block of this nerve. In group I, an additional spectrum of nerves (thoracodorsal, axillary and medial brachial cutaneous nerves) was involved compared to group A. There was no difference among groups in onset and duration of block. Conclusion: Based on the safe landmark and feasibility of this procedure and the additional spectrum of nerve block achieved, the application of lateral infraclavicular technique has to be reconsidered in clinical practice.

A large simple randomized trial of rocuronium versus succinylcholine in rapid-sequence induction of anaesthesia along with propofol.

Abstract: Background: Rocuronium has an onset of action more rapid than other non-depolarizing neuromuscular blocking agents, but it is unclear whether it and succinylcholine give equivalent intubating conditions during rapid-sequence induction of anaesthesia. We performed this study to answer the question – are there clinically relevant differences between the use of rocuronium and succinylcholine to secure acceptable intubating conditions during rapid-sequence induction of anaesthesia with propofol? Methods: Anaesthesia was induced using propofol 2.5 mg/kg in 349 ASA physical status grade I–IV patients who were undergoing either elective or emergency surgery. Propofol was followed immediately by either rocuronium 0.6 or 1 mg/kg or succinylcholine 1.0 mg/kg (randomly selected). Fifty seconds after the end of muscle relaxant injection laryngoscopy was performed and intubating conditions were graded by an experienced anaesthetist blind to the muscle relaxant allocation. This study design was selected so that a 10% difference in clinically acceptable intubating conditions between drugs would be detectable. Results: In this setting rocuronium 1.0 mg/kg provided superior intubating conditions compared with rocuronium 0.6 mg/kg. The incidence of clinically acceptable intubating conditions with rocuronium 1.0 mg/kg and succinylcholine 1.0 mg/kg was 93.2% and 97.1% respectively, the difference being −3.9% (95% C.I. −9.7% to 1.9%). Conclusion: Rocuronium 1.0 mg/kg given along with propofol in a rapid-sequence induction of anaesthesia is clinically equivalent to succinylcholine 1.0 mg/kg.

Neuroprotective properties of propofol and midazolam, but not pentobarbital, on neuronal damage induced by forebrain ischemia, based on the GABAA receptors.

Abstract: Background: The mechanism of the neuroprotective effects of propofol was compared to two other types of intravenous (i.v.) anesthetics (i.e., benzodiazepine; midazolam and barbiturate; pentobarbital) using Mongolian gerbils focusing on GABA receptor subtypes. Methods: Neuronal injury was induced by a 4-min occlusion of the common carotid arteries followed by reperfusion. One week after occlusion, animals were transcardially perfused for histochemistry. Neuronal death in four brain regions was evaluated by direct visual counting of acidophilic neurons. Results: Seven days after this ischemic episode, severe neuronal injury was measured in the hippocampal CA1 area (>98% of total cells damaged) and parietal cortex (>35%). Also lateral thalamus and caudate putamen were damaged but to a lesser extent (about 10%). The neuronal injury in these areas was significantly attenuated by propofol, midazolam and the GABAA agonist, muscimol, intraperitoneally administered 15 min prior to ischemia. This neuroprotective property, however, was lacking with pentobarbital and GABAB agonist baclofen. Concomitant pretreatment with subthreshold doses of propofol and muscimol significantly reduced the amount of cell death induced by brain ischemia. On the other hand, pretreatment with the GABAA antagonist bicuculline significantly inhibited the neuroprotective effects of propofol. However, a GABAB antagonist, phaclofen, was without effect on neuronal damage and on neuronal protection of propofol. Conclusion: These results indicate that activation of GABAA receptors, which include the specific binding subunits for propofol and midazolam, but not pentobarbital, plays a role in the inhibition of neuronal death induced by brain ischemia.

The effect of ketamine on clinical endpoints of hypnosis and EEG variables during propofol infusion

Abstract: Background: We studied the effect of variable doses of ketamine on the endpoints of hypnosis, e.g., unresponsiveness to verbal commands (UVC), loss of eyelash reflex (LER), and inhibition of body movement response with or without sneezing to nasal membrane stimulation (INBMR), and processed EEG variables, e.g., bispectral index (BIS), 95% spectral edge frequency (SEF) and median frequency (MF) during propofol infusion. Methods: Forty-eight patients received either propofol infusion, 30 mg · kg−1 · h−1 (Group P; n=12) or ketamine bolus, 0.25, 0.5 or 0.75 mg i.v., followed by propofol infusion, 30 mg · kg−1 · h−1+variable dose ketamine infusion, 0.25, 0.5 or 0.75 mg · kg−1 · h−1 (Groups PK0.25, PK0.5 and PK0.75; n=12 each) until UVC, LER and INBMR. BIS, 95% SEF and MF values were monitored and recorded at the endpoints of hypnosis. Propofol and ketamine concentrations were measured at INBMR. Results: Propofol infusion, 30 mg · kg−1 · h−1, induced UVC, LER and INBMR at BIS: 65±2, 63±9 and 33±7; 95% SEF: 17±3, 17±4 and 14±3; and MF values of 5±2, 5±3 and 3±2, respectively. With adjunctive ketamine (Groups PK0.5 and PK0.75), the hypnotic endpoints were achieved at higher BIS and 95% SEF values and lower propofol doses and concentrations as compared to Groups P and PK0.25 (9.9±5.8 and 9.4±3.4 vs. 13.4±4.5 and 14±5.8 μg · ml−1). Conclusions: Our results suggest additive interaction between propofol and ketamine (Groups PK0.5 and PK0.75) for achieving the hypnotic endpoints; however, ketamine did not depress the EEG variables in proportion to its hypnotic effect. The paradoxically higher BIS and 95% SEF values at the hypnotic endpoints may be due to lower propofol concentrations and/or no effect of ketamine on the EEG variables.

In-hospital cardiopulmonary resuscitation. 5 years' incidence and survival according to the Utstein template.

Abstract: Direct comparison of survival rates from in-hospi-tal cardiopulmonary resuscitation (CPR) remains difficult. Theobjective of this study was to report outcome according to theUtstein template for in-hospital cardiac arrest and to evaluatethe Utstein template itself as applied to a retrospective material.

Sevoflurane causes more postoperative agitation in children than does halothane.

Abstract: Background: An agitated recovery may occur after inhalation anesthesia. The aim of the present study was to assess the recovery quality after mask anesthesia with either halothane or sevoflurane in children. Methods: Sixty-two children, 8 months to 18 years of age, scheduled for minor surgery, were randomly assigned to receive either halothane or sevoflurane. The patients were premedicated with midazolam and anesthesia was induced iv with propofol or by inhalation and maintained with halothane or sevoflurane in N2O/O2 via face mask. Recovery was assessed by a “blinded” observer using a postanesthetic recovery score. Agitation and pain were judged using a visual analog scale. The incidence of vomiting was noted. The day after anesthesia older children and parents of younger children were interviewed about their experience of the anesthesia and recovery period. Results: There were no differences between groups in respect of age, weight, length, or duration of surgery or inhalational gas exposure. Median time from end of administration of inhalational agent to spontaneous eye opening was less after sevoflurane (25 min) than after halothane (48 min), (P<0.01). Likewise, recovery was faster after sevoflurane anesthesia (P<0.05). Agitation, but not pain, occurred more frequently after sevoflurane than after halothane (P<0.05) and agitation was significantly more common in younger children. There was no difference in duration of hospital stay between day-care patients in the two groups. Conclusion: Early postanesthetic agitation and recovery was faster after mask anesthesia with sevoflurane than after halothane. There was a higher incidence of agitation in younger children, without correlation to pain.

Citation analysis and journal impact factors – is the tail wagging the dog?

Abstract: THE INSTITUTE of Scientific Information (ISI) in Philadelphia has published the Science Citation Index (SCI) since 1961. It covers most major journals. It counts citations of individual articles based on references in journals indexed by the SCI. There were many reasons for this. It is interesting to see how often individual articles and researchers/research groups are cited by others. And it may be of interest to see how often the scientific market cites the individual journals. However, there has been a marked tendency to use the journal impact factors indiscriminately as the one and only measure of research quality during the last years. It is particularly disheartening to see this happening in the academic community, which should know better. As other journals – we feel an urgent need to enlighten readers, scientists and academic leaders about what is going on (1–5).

The role of stress in anaesthetists’ health and well‐being

Abstract: Stress is an inevitable part of our personal and professional lives When poorly managed, stress will accumulate to levels that become injurious to our health and well-being Burnout is one such consequence However, because stress is an activie process, with the proper knowledge and skills, we can learn to better manage and control its level of intensity This paper examines the stress cycle and especially those aspects that are unique to the practice of medicine and anaesthesia Sleep deprivation and physical fatigue are analyzed as key stressors The role of the medical marriage and dual-career relationships are scrutinized The importance of retaining the humanistic essence of medicine is emphasized Stress management strategies and coping responses, including self-care and humor, are discussed

One-lung ventilation when intubation is difficult--presentation of a new endobronchial blocker.

Abstract: Background: One-lung ventilation utilizing a double-lumen endotracheal tube may be technically difficult or inappropriate in morbidly obese or critically ill patients. In patients requiring awake fiberoptic intubation, double-lumen tube placement may be impossible. Wire-guided endobronchial blockade through a conventional endotracheal tube is a new alternative for these patients. Methods: A 44-year-old, 133 kg female patient was scheduled to undergo a thoracotomy for transthoracic fundoplication. A wire-guided endobronchial blocker (WEB) was placed following rapid-sequence induction and intubation with an 8.0 OD single-lumen endotracheal tube with the aid of a pediatric bronchoscope. Results: The WEB, using a guiding loop, was placed with ease and allowed effective one-lung ventilation. Conclusion: The WEB system allows one-lung ventilation to be achieved with a conventional endotracheal tube. The need for reintubation at the end of surgery is eliminated and endotracheal tube cross-sectional area is conserved.

Do blood levels of neuron-specific enolase and S-100 protein reflect cognitive dysfunction after coronary artery bypass?

Abstract: Background: Neuron-specific enolase (NSE) and S-100 protein have been used as markers for major brain damage. Cognitive dysfunction after cardiac surgery represents subtle brain damage that is detected by neuropsychological testing. We hypothesised that blood levels of NSE and S-100 protein would increase after coronary artery bypass surgery and that the change in blood level would correlate with the change in cognitive function. Methods: We included 35 elderly patients undergoing coronary artery bypass surgery. Neuropsychological testing was performed before surgery and postoperatively at discharge from hospital and after 3 months using a neuropsychological test battery. Serum levels of NSE and S-100 protein were measured before surgery and postoperatively after 24 h and 48 h. Results: Serum level of both NSE and S-100 protein increased significantly 24 and 48 h after coronary artery bypass. Only the increase in NSE after 24 h was found to correlate with the degree of cognitive dysfunction at discharge from hospital. The increase in S-100 protein after 24 h correlated significantly with the duration of cardiopulmonary bypass. Conclusion: NSE seems to be a useful blood marker for early cognitive dysfunction after coronary artery bypass surgery.

Diminished interleukin‐6 and C‐reactive protein responses to laparoscopic versus open cholecystectomy

Abstract: Background: Cytokines and their inhibitors are thought to be involved in many of the pathophysiological changes associated with trauma and infection. The magnitude of the trauma and the degree of tissue damage have an impact on the trauma response. The purpose of the study was to examine cytokine and hormonal responses to elective cholecystectomy and the extent to which these responses are influenced by the surgical procedure employed. Methods: Sixteen patients, ASA grades I and II, were studied: 8 of them underwent laparoscopic cholecystectomy while the remaining 8 were operated on using the open technique. Systemic concentrations of tumour necrosis factor α (TNF), interleukin-1 β (IL-1), interleukin-6 (IL-6), cortisol, epinephrine and norepinephrine were measured before and during the operation and subsequently for up to 48 h postoperatively. The degree of pain and fatigue were recorded during the study period. Results: The preoperative levels of cytokines and hormones were all similar in the groups. Concentrations of TNF and IL-1 were detected only sporadically. The rise in plasma IL-6 was less marked following laparoscopic than after open cholecystectomy. However, the hormonal response was quite similar in the two groups. Pain and fatigue scores were lower (P<0.05–0.01) in the laparoscopic group than in the open surgery group. Conclusion: In summary, cholecystectomy, irrespective of whether it was performed using the laparoscopic or open technique, was followed by a trauma response and increased pain and fatigue. However, the magnitude of stress, pain and fatigue was less pronounced in laparoscopic cholecystectomy patients. Concentrations of IL-6 seem to be more sensitive when it comes to delineating the trauma response than systemic norepinephrine and epinephrine levels.

Clinical experience using intrathecal (IT) bupivacaine infusion in three patients with complex regional pain syndrome type I (CRPS‐I)

Abstract: Background and aim: To date, there is no reliable method for treating the severe pain and for modifying the natural evolution of CRPS-I. Therefore, we explored the effect of long-term IT bupivacaine infusion (with or without buprenorphine) on this syndrome. Patients and methods: (a) Patients: two women and one man, 25, 31 and 42 years old, with CRPS-I of the lower (n=2) or upper (n=1) extremity lasting for 4 and 5 months, and 14 years. (b) Interventions: insertion of externalized IT catheters; IT infusion of buprenorphine 0.015 mg/ml and bupivacaine 4.75 mg/ml (n=1), or only bupivacaine 5 mg/ml (n=2) from external electronic pumps. Results: The IT treatment lasted for 172, 282 and 668 days. The mean/maximal daily doses of the IT bupivacaine were 39/66, 55/80 and 69/125 mg, respectively. The pain intensity decreased from VASmean=7±1 to VASmean=2±2. None of the patients had regression of allodynia, edema, and trophic disturbances in the affected extremities. In 2 patients, the IT treatment did not prevent spread of the disease to the opposite extremity or the occurrence of phantom pain and stump allodynia after amputation. The IT catheters were withdrawn as being no longer needed: in 2 patients 56 and 458 days after amputation of the involved extremity, and in another one before replacement of the IT bupivacaine infusion with epidural dorsal column stimulation (EDCS). After termination of the IT treatment, the patients were observed for 1437, 1575, and 2689 days (until September 1, 1998). At that date, all the patients were alive, and still affected by their CRPS-I, either in the amputation stump (n=2), and/or in the opposite or remote extremities (n=2); further, two were unemployed and one worked for 75% of the time. One of them was taking up to 1500 mg of slow-release morphine to cope with pain. Conclusion: The IT pain treatment with bupivacaine (with or without buprenorphine) alleviated the “refractory” pain, but affected neither the associated symptoms and signs of the CRPS-I, nor its natural evolution. Thus, the IT treatment cannot be recommended in preference to other pain treatment regimens for CRPS-I.

Intraarticular, epidural, and intravenous analgesia after total knee arthroplasty.

Abstract: Background: After total knee arthroplasty, patients regularly suffer from severe pain. It is unclear whether epidural or systemic pain therapy is superior in terms of postoperative pain relief, patients’ comfort and side effects. A new therapeutic approach, intraarticular opioids, has been suggested with the detection of opioid receptors in inflamed tissue. This method has proven suitable for clinical use in small operations (e.g. knee arthroscopy). In this study, we compared epidural analgesia and intraarticular application of morphine plus “on-demand” intravenous analgesia to “on-demand” intravenous analgesia alone. Methods: Thirty-seven patients, scheduled for total knee arthroplasty, were randomly assigned to three treatment groups: in group 1 (EPI) patients received bolus doses of morphine via an epidural catheter; in group 2 (IA) an intraarticular bolus of 1 mg of morphine was applied at the end of the operation with subsequent use of a patient-controlled analgesia (PCA) pump; group 3 (Control), in which only PCA was provided, served as control for both analgesic procedures. Main outcome measures included visual analogue pain scales, total morphine consumption, and stress hormones. Results: No statistically significant differences in visual analogue pain scales could be detected between the three groups. Application of intraarticular morphine did not reduce the amount of analgesics required for postoperative analgesia as compared to intravenous analgesia alone. Application of epidural morphine significantly suppressed β-endorphine release, but did not significantly influence other stress hormones as compared to the control group. Conclusion: Epidural and intravenous analgesia after total knee arthroplasty are equivalent methods of pain relief. In major orthopaedic procedures, application of intraarticular morphine does not reduce analgesic requirements.

Preoperative anxiety is associated with a high incidence of problematic behavior on emergence after halothane anesthesia in boys.

Abstract: Background: In our clinical experience, children who are crying before anesthesia are more likely to show agitated behavior on emergence. Methods: One hundred and ten boys aged 3–6 years old (ASA 1) who underwent circumcision were studied. The children were assigned to one of two groups, depending on their attitude during induction: the anxious group and the calm group. Anesthesia was induced by inhalation of halothane in oxygen, and was maintained at 1% throughout surgery. For intra- and postoperative analgesia, caudal block with 0.5 ml/kg of 0.25% plain bupivacaine and topical infiltration with 1 to 2 ml of 1% lidocaine were provided for all patients. The incidence of delirium on emergence was compared between the groups. Results: We excluded 4 boys showing signs of incomplete pain relief. Twenty of 27 boys in the anxious group showed a significantly greater incidence of problematic behavior on emergence, compared to 5 of 79 in the calm group. Conclusion: The boys who were anxious before anesthesia showed a significantly greater incidence of problematic behavior on emergence from halothane anesthesia, compared with the boys who were calm before anesthesia.

Intra-articular morphine for pain relief after knee arthroscopy.

Abstract: Background: Peripheral opioid analgesia is well documented. But the clinical usefulness of intra-articular morphine after surgery is uncertain. The aim of the present study was to evaluate the analgesic effects of intra-articular morphine after knee arthroscopy. Methods: In this parallel-group, double-blind study, 90 patients were randomised to receive either morphine 1 mg, morphine 2 mg or placebo in 5 ml saline intra-articularly at the end of arthroscopic knee surgery. Anaesthetic technique was local infiltration and intra-articular injection of lidocaine. Analgesic efficacy was evaluated by a global pain score, pain intensity (visual analogue scale), and analgesic requirements (paracetamol) during the first 48 h postoperatively. Results: No significant differences between the groups were found for any of the efficacy variables. A majority of the patients had mild pain throughout the study, thus possibly compromising study sensitivity. In a subgroup with more intense pain early after arthroscopy, intra-articular morphine 2 mg reduced pain intensity (P<0.05) and analgesic requirements (P<0.05) compared with placebo. Conclusion: Postoperative analgesic effect of intra-articular morphine was found only in a subgroup of patients with higher pain intensity in the immediate postanaesthetic period. Possible reasons for our overall negative findings include low study sensitivity due to weak pain stimulus, lack of inflammation that may be a prerequisite for peripheral opioid analgesia, and the local anaesthetic, which impedes local inflammatory reaction and expression of peripheral opioid receptors. These factors may also explain the conflicting results in other studies.

Economic implications of pain management.

Abstract: Background: Economic issues in pain management affect the patient, the provider and society. This paper will review some of the data on the costs to society of chronic pain and its associated disability. It will also look at the costs to patient and provider of alternative economic models. Conceptual issues that underlie health care delivery and the attendant costs must be addressed if society is to gain control over runaway health care costs and reduce the economic burden of chronic pain and disability for the patient as well as the provider. Methods: Literature review and synthesis. Results: Chronic pain is the primary cause of health care consumption and disability in the working years. Multidisciplinary pain clinics have proven utility. Data on efficacy of most other kinds of care is lacking. Disability costs are related to conceptual inadequacies and the medicalization of post-industrial societies. Conclusion: To control inappropriate care and escalating costs, we must change concepts of pain and disability and the methods of funding both of these in relation to chronic pain. The outcome of the continuing struggle between the profession of medicine, the state and capitalists will determine how and whether pain management is a part of medical care.

Axillary brachial plexus block with ropivacaine 7.5 mg/ml. A comparative study with bupivacaine 5 mg/ml.

Abstract: Background: Ropivacaine is less cardiotoxic than bupivacaine and may be used in higher doses in order to increase the quality of a block. The aim of this study was to compare the efficacy and safety of 40 ml ropivacaine 7.5 mg/ml (300 mg) and 40 ml bupivacaine 5 mg/ml (200 mg) for axillary plexus block. Methods: One hundred and four adult patients were included in a prospective , double-blind study. Sensory and motor block were tested for the five main terminal nerves of the arm at 10-min intervals until start of surgery and every second hour thereafter until full resolution of the block. Results: The overall evaluation of the block by the surgeon and the anesthesiologist showed a significantly better quality in the ropivacaine patients, regarding both anesthesia and motor block. There were no differences in the time to onset and duration of the block. Except for one patient, who had seizures after an accidental IV injection of ropivacaine, there were no major side effects. Conclusion: Ropivacaine 7.5 mg/ml, 40 ml, produces axillary plexus block of similar onset and duration but better quality than 40 ml of bupivacaine 5.0 mg/ml.

Opioid use in cancer pain. Is a more liberal approach enhancing toxicity

Abstract: The majority of cancer patients develop pain before death. This pain has been shown to be underdiagnosed and undertreated. Opioid use has increased in the past 20 years in both developing and developed countries. The changing pattern in opioid use has resulted in the emergence of neurotoxicity as a major side effect of the treatment of cancer pain. The syndrome of opioid-induced neurotoxicity (OIN) encompasses delirium, hallucinosis, myoclonus/seizures and hyperalgesia. Increased vigilance can lead to the timely diagnosis of OIN, and strategies for its treatment can be implemented with encouraging results. Identification and modification of risk factors for the development of OIN can help in its prevention and improve the quality of life in advanced cancer patients.

Cauda equina syndrome after spinal anaesthesia with hyperbaric 5% lignocaine: a review of six cases of cauda equina syndrome reported to the Swedish Pharmaceutical Insurance 1993-1997.

Abstract: Six cases of cauda equina syndrome with varying severity were reported to the Swedish Pharmaceutical Insurance during the period 1993-1997. All were associated with spinal anaesthesia using hyperbaric 5% lignocaine. Five cases had single-shot spinal anaesthesia and one had a repeat spinal anaesthetic due to inadequate block. The dose of hyperbaric 5% lignocaine administered ranged from 60 to 120 mg. Three of the cases were most likely caused by direct neurotoxicity of hyperbaric 5% lignocaine. In the other 3 cases, direct neurotoxicity was also probable, but unfortunately radiological investigations were not done to definitely exclude a compressive aetiology. All cases sustained permanent neurological deficits. We recommend that hyperbaric lignocaine should be administered in concentrations not greater than 2% and at a total dose preferably not exceeding 60 mg.

Mild hypothermia does not increase blood loss during total hip arthroplasty

Abstract: BACKGROUND The effects of mild hypothermia on blood loss are little known. METHODS Patients, undergoing primary prosthetic hip surgery under spinal anaesthesia, were randomised to the operative procedure, with (n=25) or without (n=25) forced air warming. Core temperature was repeatedly measured from the tympanic membrane. The blood loss was calculated by three different methods; the intraoperative loss was estimated visually. The loss during and after the operation was obtained by determination of lost haemoglobin (the Hb-method). The blood loss during hospital stay was also calculated from the haemoglobin balance. RESULTS Among controls, core temperature decreased by 1.3+/-0.6 degrees C (mean+/-SD) and in the warmed patients 0.5+/-0.4 degrees C (P<0.0001). Preoperative variables and the number of allogeneic units transfused did not differ between the groups. In controls, the blood loss during operation was, with the visual method, 698+/-314 ml, compared with 665+/-292 ml in warmed patients. With the Hb-method, the loss was 662+/-319 and 657+/-348 ml, respectively. With this method, the external loss during the entire hospital stay was, in controls, 1066+/-441 ml and in the warmed group, 1047+/-413 ml. The balance method yielded 1674+/-646 ml and 1507+/-652 ml, respectively. Indices of blood loss did not differ significantly between groups and there was no covariation between those variables and the decrease in core temperature. CONCLUSIONS Forced air warming did not decrease the blood loss. Methods for determination of blood loss yielded widely differing results.

Errors in the intensive care unit (ICU). Experiences with an anonymous registration.

Abstract: Background: In order to obtain information about the occurrence and severity of errors in an ICU, this investigation was conducted in a combined ICU and postoperative ward at a Norwegian University Hospital. Methods: An anonymous registration was conducted in order to reveal as many as possible of all errors in the unit. A separate registration form was used, recording the type of error, date and time, sex and age of the patient, patient condition (unstable/stable) and where the error occurred (on the ward or during transport). The registration started in October 1995, and reports until November 1996 are included (13 months). Consequences of the errors were graded using a 6-point scale (0=no consequences and 5=fatal). Two experienced intensivists and two experienced ICU nurses independently evaluated the errors using a visual analogue scale (VAS) with 10 as the worst imaginable error. All four were blinded to consequences of the error. Results: A total of 87 errors was reported: 36 (41.3%) were medication errors, 17 (19.5%) related to intravenous infusions, 15 (17.2%) were due to technical equipment failure, and the rest (19 errors, 21.8%) miscellaneous. No consequences could be detected in 55 cases (63%) (grade 0). Six errors were graded as 1, and 22 (25%) as grade 2 (therapeutic intervention necessary, no damage recorded). Five errors had more serious consequences, and one was fatal. The scoring of errors varied a great deal. Mean VAS score was 4.2 (SD 1.7). The sum of VAS score (max. 40) on each error followed a normal distribution, and 12 errors had a score >25. Conclusion: Errors happen frequently in the ICU. Probably, our data do not represent the true incidence of errors in the period, which we believe was higher. Many errors are graded as serious or severe, but still have limited consequences for the patient.

A review of recovery from sevoflurane anaesthesia: comparisons with isoflurane and propofol including meta-analysis.

Abstract: Background: Sevoflurane has a lower blood:gas partition coefficient than isoflurane and thus should be associated with a more rapid recovery from anaesthesia. Methods: A review and meta-analysis were employed to examine the recovery profiles of adult patients following anaesthesia, comparing sevoflurane to isoflurane and sevoflurane to propofol. Results: There were significant differences in times to several recovery events that favoured sevoflurane to isoflurane anaesthesia, including time to emergence, response to commands, extubation, and orientation. Likewise, there were significant differences in times to the same recovery events following anaesthesia with sevoflurane versus propofol. There were no differences in time to recovery room discharge when comparing sevoflurane to isoflurane or propofol. Conclusion: The observed differences between sevoflurane and isoflurane or propofol anaesthesia support the postulate that the use of sevoflurane is associated with a more rapid recovery from anaesthesia than either isoflurane or propofol.

Lack of pre-emptive analgesic effect of (R)-ketamine in laparoscopic cholecystectomy.

Abstract: Aim: This study evaluated the pre-emptive analgesic effect of intravenous (i.v.) (R)-ketamine in laparoscopic cholecystectomy. (R)-ketamine was used due to the lower incidence of side-effects. Methods: Sixty patients who underwent surgery under general anesthesia were randomly allocated to 3 groups and studied in a double-blind manner. Two i.v. injections were administered: one after induction of anesthesia, approximately 3 min before surgery, and one after surgery. The placebo group (PLA, n=20) received saline in both injections. The preoperative group (PRE, n=20) received (R)-ketamine 1 mg/kg and then saline. The postoperative group (POST, n=20) received saline and then (R)-ketamine 1 mg/kg. Postoperatively, the patients used a patient-controlled analgesia (PCA) pump. Pain was evaluated with a visual analog scale (VAS) at 30 min and every hour for 4 h and with a verbal rating scale (VRS) at 24 h and after 7 days. Results: There were no occurence of side-effects from (R)-ketamine. VAS and VRS at 1, 2, 3, and 4 h postoperatively showed no statistical differences. In the POST group, extubation was delayed and pain score (VAS) at 30 min postoperatively was significantly lower (P<0.05) than the two other groups. There were no statistical differences in meperidine consumption during the first 4 h postoperatively and no differences in consumption of analgesics at 24 h and 7 days. Conclusion: In this study a 1 mg/kg dose of (R)-ketamine given at the end of surgery exerted a short-lasting hypnotic and analgesic effect. The same dose given preoperatively did not show postoperative analgesic effect or pre-emptive effect.