Showing papers in "Acta Anaesthesiologica Scandinavica in 2004"

Description of the Entropy algorithm as applied in the Datex-Ohmeda S/5 Entropy Module.

Abstract: H. VIERTIÖ-OJA, V. MAJA, M. SÄRKELÄ, P. TALJA, N. TENKANEN, H. TOLVANEN-LAAKSO, M. PALOHEIMO, A. VAKKURI, A. YLI-HANKALA and P. MERILÄINEN Datex-Ohmeda Division, Instrumentarium Corp., Helsinki, Department of Anesthesia, Eye and Ear Hospital, Helsinki University Hospital, Helsinki, Department of Anesthesia, Surgical Hospital, Helsinki University Hospital, Helsinki, Department of Anesthesia, Tampere University Hospital, and University of Tampere, Medical School, Tampere, and Instrumentarium Corp., Helsinki, Finland

Reduction in the incidence of awareness using BIS monitoring.

Abstract: Background: Explicit recall (ER) is evident in approximately 0.2% of patients given general anaesthesia including muscle relaxants. This prospective study was performed to evaluate if cerebral moni ...

Chronic pain following Caesarean section.

Abstract: Background: Chronic postoperative pain is a well-recognized problem after various types of surgery such as amputation, thoracotomy, mastectomy, gallbladder surgery and inguinal hernia repair. However, little is known about chronic pain after gynaecologic surgery. Therefore, the aim was to study the incidence of chronic pain after Caesarean section. Methods: A questionnaire was sent in February/March 2003 to 244 consecutive patients who underwent Caesarean section in a one-year period from 1 October 2001 to 30 September 2002. Patients were asked about duration of postoperative abdominal scar pain, and if pain was still present to describe the frequency and intensity of pain and its impact on daily life. The questionnaire also included questions about the Caesarean section and about pain problems elsewhere. Results: A total of 220 patients (90.2%) answered the questionnaire. The mean follow-up time was 10.2 months (range 6–17.6). Postoperative pain resolved in most patients within 3 months but 27 patients (12.3%) still had pain at the time of the interview. No patients had constant pain, but in 13 of 27 patients (5.9%) pain was present daily or almost daily. Patients with persistent pain (n = 27) had more often undergone general than spinal anaesthesia for the Caesarean section. Frequencies of pain problems elsewhere and recalls of severe acute postoperative pain were also higher among patients with persistent pain. Conclusion: Chronic pain after Caesarean section seems to be a significant problem in at least 5.9% of patients.

The 118 A > G polymorphism in the human mu-opioid receptor gene may increase morphine requirements in patients with pain caused by malignant disease.

Abstract: The number of cancer patients in the world is increasing mainly because of ageing populations. In developed countries it is estimated that about one in three will get cancer during their lifetime. In addition to anticancer treatment, pain treatment at all stages of the cancer disease is of high priority and an ongoing challenge in clinical practice. Whilst oral morphine has been the first line drug of choice for moderate to severe cancer pain, 10-30 % of patients treated with morphine do not have successful outcomes, either because of intolerable adverse effects or inadequate analgesia - or a combination of both. Another issue of morphine treatment is that in cases where it does prove efficient, the dose needed to relieve pain varies widely between patients. One explanation of the interindividual variation in response to morphine may lie within the genes. How many genes are involved, and which variation within well studied genes and yet unknown genes, however, is still an unraveled puzzle. Pharmacogenetics is the studies of how genetic variability influences the responses to drugs. In this thesis, using a pharmacogenetic approach, we have investigated the geneopioid interaction in patients receiving oral morphine for cancer pain. The genetic focus in this thesis has been on two systems, the μ-opioid receptor system and the catechol-O-methyltransferase system. The μ-opioid receptor is the major site for activation of most clinically important opioids, including morphine. Therefore, the gene encoding the μ-opioid receptor (the-OPRM1 gene) was selected for investigation. Catecholamines are involved in the modulation of pain and are partly metabolized by the catechol-O-methyltransferase (COMT) enzyme. Variation within the COMT gene is believed to influence pain sensitivity and therefore we hypothesized that the COMT gene is a contributor that influences the response of morphine in cancer pain treatment. Our findings indicate that genetic variation in the OPRM1 and the COMT genes are influencing the analgesic effect of morphine for patients experiencing cancer pain. Our data also indicate that two genetic variants of the OPRM1 and COMT genes display joint effects, but larger cohorts are needed to investigate whether these effects are enhancing the efficacy of morphine. The phenotype “morphine response in cancer pain treatment” is a multiplex phenotype that has a complex genetic basis. Most likely more than two genes influence the phenotype. We are only at the beginning of the journey towards a better understanding of the complex biology of opioid response.

'Protective premedication': an option with gabapentin and related drugs? A review of gabapentin and pregabalin in the treatment of post-operative pain

Abstract: Substantial progress has been made during the last decades in our understanding of acute pain mechanisms, and this knowledge has encouraged the search for novel treatments. Of particular interest has been the observation that tissue injury initiates a number of modulations of both the peripheral and the central pain pathways, which convert the system from a 'physiological' to a 'pathological' mode of processing afferent information. Gabapentin, which binds to the alpha(2)delta subunit of the voltage-dependent calcium channel, is active in animal models of 'pathological' but not in models of 'physiological' pain. Consequently, attention has so far been focused on neuropathic pain as a target for the clinical use of gabapentin and analogues. Recently, several reports have indicated that gabapentin may have a place in the treatment of post-operative pain. This article presents a brief summary of the potential mechanisms of post-operative pain, and a systematic review of the available data of gabapentin and pregabalin for post-operative analgesia. It is concluded that the results with gabapentin and pregabalin in post-operative pain treatment published so far are promising. It is suggested that future studies should explore the effects of 'protective premedication' with combinations of various antihyperanalgesic and analgesic drugs for post-operative analgesia.

Time-frequency balanced spectral entropy as a measure of anesthetic drug effect in central nervous system during sevoflurane, propofol, and thiopental anesthesia

Abstract: 88 � 13% ,a nd 63� 14%, respectively. The relative rise was higher in RE and SE compared with BIS (P <0.01). During deep levels of hypnosis, RE and SE decreased monotonously as a function of burst suppression ratio, while BIS showed biphasic behavior. On average, RE indicated emergence from anesthesia 11s earlier than SE, and 12.4s earlier than BIS. Conclusions: All indices, RE, SE, and BIS, distinguished excellently between conscious and unconscious states during propofol, sevoflurane, and thiopental anesthesia. During burst suppression, Entropy parameters RE and SE, but not BIS, behave monotonously. During regaining of consciousness after a thiopental or propofol bolus, RE and SE values recovered significantly closer to their baseline values than did BIS. Response entropy indicates emergence from anesthesia earlier than SE or BIS.

Abolished circadian rhythm of melatonin secretion in sedated and artificially ventilated intensive care patients.

Abstract: Background: Sleep disturbance is common in intensive care patients. Aside from its unpleasantness, there is a correlation with intensive care unit (ICU) syndrome/delirium. Reasons for sleep deprivation appear to be multifactorial, including the underlying illness, an acute superimposed disturbance, medications, and the ICU environment itself. There are reasons to believe that alterations of the 'biological clock' might contribute. Melatonin secretion is one reflection of this internal sleep/wake mechanism. Melatonin levels are normally high during the night and low during daytime, being suppressed by bright light. Methods: Melatonin levels in blood and urine were studied over 3 consecutive days in eight critically ill patients during deep sedation and mechanical ventilation. Sedation was assessed with the sedation-agitation (SAS) scale and bispectral index (BIS) monitor. Results: The circadian rhythm of melatonin release was abolished in all but one patient, who recovered much more quickly than the others. There was no correlation between melatonin levels and levels of sedation. Conclusions: This study indicates that dyssynchronization of the melatonin secretion rhythm is common in critically ill and mechanically ventilated patients. It could be hypothesized that an impairment of the melatonin rhythm may play a role in the development of sleep disturbances and delirium in intensive care patients, and that melatonin supply could reduce the incidence of these phenomena.

Effects of gabapentin on postoperative morphine consumption and pain after abdominal hysterectomy: a randomized, double-blind trial.

Abstract: Background: Preliminary clinical studies have suggested that gabapentin may produce analgesia and reduce the need for opioids in postoperative patients. The aim of the present study was to investigate the opioid-sparing and analgesic effects of gabapentin administered during the first 24 h after abdominal hysterectomy. Methods: In a randomized, double-blind study, 80 patients received oral gabapentin 1200 mg or placebo 1 h before surgery, followed by oral gabapentin 600 mg or placebo 8, 16 and 24 h after the initial dose. Patients received patient-controlled analgesia with morphine at doses of 2.5 mg with a lock-out time of 10 min for 24 h postoperatively. Pain was assessed on a visual analogue scale (VAS) at rest and during mobilization, nausea, somnolence and dizziness on a four-point verbal scale, and vomiting as present/not present at 2, 4, 22 and 24 h postoperatively. Results: Thirty-nine patients in the gabapentin group, and 32 patients in the placebo group completed the study. Gabapentin reduced total morphine consumption from median 63 (interquartile range 53–88) mg to 43 (28–60) mg (P < 0.001). We observed a significant inverse association between plasma levels of gabapentin at 2 h postoperatively, and morphine usage from 0 to 2 h, and from 0 to 4 h postoperatively (R2 = 0.30, P = 0.003 and R2 = 0.24 P = 0.008, respectively). No significant differences in pain at rest or during mobilization, or in side-effects, were observed between groups. Conclusion: Gabapentin in a total dose of 3000 mg, administered before and during the first 24 h after abdominal hysterectomy, reduced morphine consumption with 32%, without significant effects on pain scores. No significant differences in side-effects were observed between study-groups.

A systematic review of COX-2 inhibitors compared with traditional NSAIDs, or different COX-2 inhibitors for post-operative pain

Abstract: Background: We have reviewed the analgesic efficacy of cyclooxygenase-2 (COX-2) inhibitors compared with traditional non-steroidal anti-inflammatory drugs (NSAIDs), different COX-2 inhibitors, and placebo in post-operative pain. Methods: Randomized controlled trials were evaluated. Outcome measures were pain scores and demand for supplementary analgesia 0–24 h after surgery. Results: Thirty-three studies were included in which four COX-2 inhibitors, rofecoxib 50 mg, celecoxib 200 and 400 mg, parecoxib 20, 40 and 80 mg, and valdecoxib 10, 20, 40, 80 mg were evaluated. Ten of these studies included 18 comparisons of rofecoxib, celecoxib, or parecoxib with NSAIDs. Rofecoxib 50 mg and parecoxib 40 mg provided analgesic efficacy comparable to that of the NSAIDs in the comparisons, and with a longer duration of action after dental surgery but possibly not after major procedures. Celecoxib 200 mg and parecoxib 20 mg provided less effective pain relief. Four studies included five comparisons of rofecoxib 50 mg with celecoxib 200 and 400 mg. Rofecoxib 50 mg provided superior analgesic effect compared with celecoxib 200 mg. Data on celecoxib 400 mg were too sparse for firm conclusions. Thirty-three studies included 62 comparisons of the four COX-2 inhibitors with placebo and the COX-2 inhibitors significantly decreased post-operative pain. Conclusion: Rofecoxib 50 mg and parecoxib 40 mg have an equipotent analgesic efficacy relative to traditional NSAIDs in post-operative pain after minor and major surgical procedures, and after dental surgery these COX-2 inhibitors have a longer duration of action. Besides, rofecoxib 50 mg provides superior analgesic effect compared with celecoxib 200 mg.

Airway pressure release ventilation as a primary ventilatory mode in acute respiratory distress syndrome

Abstract: Background: Airway pressure release ventilation (APRV) is a ventilatory mode, which allows unsupported spontaneous breathing at any phase of the ventilatory cycle. Airway pressure release ventilation as compared with pressure support (PS), another partial ventilatory mode, has been shown to improve gas exchange and cardiac output. We hypothesized whether the use of APRV with maintained unsupported spontaneous breathing as an initial mode of ventilatory support promotes faster recovery from respiratory failure in patients with acute respiratory distress syndrome (ARDS) than PS combined with synchronized intermittent ventilation (SIMV-group). Methods: In a randomized trial 58 patients were randomized to receive either APRVor SIMV after a predefined stabilization period. Both groups shared common physiological targets, and uniform principles of general care were followed. Results: Inspiratory pressure was significantly lower in the APRV-group (25.9 � 0.6 vs. 28.6 � 0.7 cmH2O) within the first week of the study (P ¼0.007). PEEP-levels and physiological variables (PaO2/FiO2-ratio, PaCO2, pH, minute ventilation, mean arterial pressure, cardiac output) were comparable between the groups. At day 28, the number of ventilator-free days was similar (13.4 � 1.7 in the APRV-group and 12.2 � 1.5 in the SIMV-group), as was the mortality (17% and 18%, respectively). Conclusion: We conclude that when used as a primary ventilatory mode in patients with ARDS, APRV did not differ from SIMV with PS in clinically relevant outcome.

The effect of carbon dioxide, respiratory rate and tidal volume on human heart rate variability

Abstract: Background: Heart rate variability (HRV) has been used for assessment of depth of anesthesia. Alterations in respiratory rate and tidal volume modulate the sympatovagal neural drive to the heart. The changes in PaCO2 that accompany changes in breathing pattern may, through chemoreceptors in the brainstem, independently influence the autonomic control of the heart and modulate HRV. Methods: We measured the effects of PaCO 2 , tidal volume and respiratory rate on HRV during spontaneous and mechanical ventilation in 22 healthy volunteers and in 25 mechanically ventilated anesthetized patients. Results: Adding CO 2 to the inspiratory gas increased high frequency (HF) and low frequency (LF) components of HRV in awake volunteers both during spontaneous and mechanical ventilation, while this effect of CO 2 was abolished in patients during anesthesia. Increase of tidal volume increased HF component of HRV only in volunteers during spontaneous ventilation. On the other hand, when respiratory rate was reduced, the balance of HF and LF power moved toward LF power in all study groups. Breathing frequency altered HRV independent on PaCO 2 , tidal volume and the level of consciousness. In contrast, the effect of PaCO 2 appeared to be related to normal level of consciousness, suggesting that a cortical modulation of the autonomic nervous activity contributes to the effects of PaCO 2 on HRV. Conclusions: PaCO 2 , tidal volume and respiratory rate should be controlled when HRV power spectrum is measured in conscious patients or volunteers, while in anesthetized patients small changes in end-tidal CO 2 or tidal volume do not modulate HRV if respiratory rate remains unchanged.

Glucocorticoid regulation of the inflammatory response to injury.

Abstract: During the first half of the 20th century, physiologists were interested in the adrenal glands primarily because adrenalectomized animals failed to survive even mild degrees of systemic stress. It eventually became clear that hormones secreted by the adrenal cortex were critical for survival and, in this context, adrenal cortical hormones were widely considered to support or stimulate important responses to stress or injury. With the purification and manufacture of adrenal cortical hormones in the 1930s and 1940s, clinicians suddenly discovered the potent anti-inflammatory actions of glucocorticoids (GCs). This dramatic, and unexpected, discovery has dominated clinical and laboratory research into GC actions throughout the second half of the 20th century. More recent research is again reporting GC-induced stimulatory effects on a variety of inflammatory response components. These effects are usually observed at low GC concentrations, close to concentrations that are observed in vivo during basal, unstimulated states. For example, GC-mediated stimulation has been reported for the hepatic acute-phase response, for cytokine secretion, expression of cytokine/chemokine receptors, and for the pro-inflammatory mediator, macrophage migration inhibition factor. It seems clear that the long-held clinical view that GCs act solely as anti-inflammatory agents needs to be re-assessed. Varying doses of GCs do not lead simply to varying degrees of inflammation suppression, but rather GCs can exert a full range of effects from permissive to stimulatory to suppressive.

The analgesic effect of intravenous ketamine and lidocaine on pain after spinal cord injury.

Abstract: Background: Pain following spinal cord injury (SCI) is a therapeutic challenge. Only a few treatments have been assessed in randomized, controlled trials. The primary objective of the present stud ...

Early bioavailability of paracetamol after oral or intravenous administration.

Abstract: Background: Paracetamol is a peripherally acting analgesic commonly used in multimodal post-operative pain management to reduce the need for more potent analgesics with their unwanted side-effects

Methylprednisolone intravenously 1 day after surgery has sustained analgesic and opioid-sparing effects.

Abstract: Background: In previous studies on glucocorticoids for postoperative pain, the test drug has been given perioperatively, usually before measurement of baseline pain. In order to evaluate the time course and magnitude of the analgesic effect of a glucocorticoid in well-established postoperative pain, we compared methylprednisolone with ketorolac and placebo, after assessment of baseline pain on the first postoperative day. Methods: This was a double-blind, single dose, randomized, parallel comparison of intravenous (i.v.) methylprednisolone 125 mg, ketorolac 30 mg as an active control, and placebo in 75 patients with moderate to severe pain 1 day after orthopaedic surgery. Outcome variables were pain intensity (0–100 VAS), pain relief (0–4 PAR) and rescue opioid consumption. Results: Methylprednisolone was not significantly different from ketorolac and gave significantly lower pain intensity from 1 h (0–6 h, P 50%maxTOTPAR6 h ) was 3.6 for methylprednisolone and 3.1 for ketorolac. Number needed to treat calculated from the percentage reporting at least 50% pain relief for at least 4 h (>50%PAR4 h) was 2.8 for both groups. Opioid consumption was significantly reduced for 72 h after methylprednisolone compared with ketorolac (P < 0.02) and placebo (P < 0.003). Conclusion: Methylprednisolone 125 mg i.v. 1 day after surgery gave similar early reduction of pain as i.v. ketorolac 30 mg. Less pain than placebo 24 h after methylprednisolone, and lower opioid consumption for 72 h compared with ketorolac and placebo indicate sustained analgesic effects of methylprednisolone.

Clonidine vs. midazolam as premedication in children undergoing adeno-tonsillectomy: a prospective, randomized, controlled clinical trial.

Abstract: Background: Clonidine administration in the setting of paediatric anaesthesia is associated with a number of desirable effects, e.g. preoperative sedation, analgesia and reduced anaesthetic requirements. The aim of the current study was to compare postoperative outcome variables using a prospective, randomized, double-blind design after premedication with clonidine or midazolam. Methods: One hundred paediatric ASA physical status 1 patients (age 1–11 year) scheduled for adeno-tonsillectomy were assigned to receive rectal premedication with midazolam (300 µg kg−1 and atropine 40 µg kg−1; group M, n = 52) or clonidine (5 µg kg−1 and atropine 40 µg kg−1; group C, n = 48) prior to a standardized sevoflurane anaesthetic. The incidence of immediate postoperative pain (0–2 h), as assessed by repeated Objective Pain Scale (OPS) scores, was chosen as the primary end-point of the study. Degree of sedation (modified Vancouver sedation scale 0–3), occurrence of postoperative vomiting (POV), and incidence of shivering and immediate postoperative confusion were registered as secondary end-points. After hospital discharge parents were instructed to continue the evaluation of pain, sedation, POV and sleep pattern during a 24-h period. Parents were also asked for their preference concerning the postoperative behaviour of their child (calm, sedated vs. alert, active). Results: In the early postoperative period patients in the clonidine group had a significantly lower sum of 5 OPS scores (median = 8.0) compared to group M (median = 11.5) (P = 0.011). Administration of clonidine was also associated with a slightly higher sum of sedation scores (median = 13) in the early postoperative period compared to children receiving midazolam (median = 12) (P< 0.001). No episode of shivering was observed in the clonidine group but was present in five of the patients in the midazolam group (P = 0.057). In younger children (<5 years) the incidence of postoperative confusion was lower in the clonidine group (P = 0.001). No difference in the frequencies of POV incidences, degree of postoperative pain, need for analgesics, or sleep pattern during the first 24 postoperative hours could be observed between the groups according to the parental evaluation. Children premedicated with clonidine were more calm and sedated compared to children in the midazolam group (P = 0.024) as judged by their parents. A significant majority of parents (75%; P<0.001) preferred a calm and sedated child during the first postoperative 24-h period. Conclusion: Rectal premedication with clonidine was associated with a significant reduction of pain in the early postoperative period compared to midazolam and was also associated with moderately increased sedation during the first 24 postoperative hours. The sedative effect of clonidine is in agreement with the unambiguous finding of a parental preference for a calm and sedated child during the first 24 postoperative hours.

Both lung recruitment maneuver and PEEP are needed to increase oxygenation and lung volume after cardiac surgery.

Abstract: Background: Patients ventilated after cardiac surgery commonly have impaired oxygenation, mainly due to lung collapse. We have previously found that PaO 2 and end-expiratory lung volume (EELV) were increased by a lung recruitment maneuver (LRM) followed by positive end-expiratory pressure (PEEP). The aim of this study was to evaluate whether only PEEP or only a LRM could give similar effects. Methods: Thirty circulatory stable patients (aged 55-79 years) mechanically ventilated after cardiac surgery were randomized to receive LRM (four 10-s insufflations to an airway pressure of 45 cmH 2 O) and zero end-expiratory pressure (LRM-group), PEEP 12 cmH 2 O (PEEP-group) or LRM in combination with PEEP 12 cmH 2 O (LRM + PEEP-group). The set end-expiratory pressure was kept for 75 min. Before, during and after the intervention, EELV (SF 6 washout technique) and blood gases were measured. Results: Initial EELV and PaO 2 were similar in all groups. In the LRM-group, PaO 2 and EELV increased transiently (P < 0.0001), but returned at 5 min to the initial values. In the PEEP-group, PaO 2 did not change but EELV increased to 155 ± 27% of the initial value (P < 0.0001). In the LRM+PEEP-group, PaO 2 and EELV increased to 212 ± 66% and 178 ± 31% of the initial values (P < 0.0001), respectively, and were maintained during PEEP application. Conclusion: In patients ventilated after cardiac surgery: (1) PEEP increased lung volume but not PaO 2 , (2) a lung recruitment maneuver without subsequent PEEP had no sustained effect, and (3) both a lung recruitment maneuver and PEEP were needed to increase and maintain the increased lung volume and PaO 2 .

Presurgical intravenous parecoxib sodium and follow‐up oral valdecoxib for pain management after laparoscopic cholecystectomy surgery reduces opioid requirements and opioid‐related adverse effects

Abstract: Background: Opioids are associated with numerous adverse effects. It is unclear if reduced postoperative opioid consumption lowers the incidence and severity of opioid-related adverse effects. This analysis – from a multicenter, randomized, double-blind trial – tested if the reduction of opioid consumption among patients who received intravenous preoperative parecoxib 40 mg, followed by oral valdecoxib 40 mg qd postoperatively, in Days 1–4 after outpatient laparoscopic cholecystectomy surgery, reduced opioid-related symptoms. Methods: Patients received intravenous fentanyl for pain before discharge, and oral acetaminophen 500 mg hydrocodone 5 mg q 4–6 h prn postdischarge for up to 7 days postsurgery. Patients also received intravenous parecoxib 40 mg administered 30–45 min preoperatively, and valdecoxib 40 mg qd up to Day 4 and prn Days 5–7 postsurgery, or placebo. Patients completed an opioid-related Symptoms Distress Scale (SDS) questionnaire every 24 h for 7 days. Opioid use was converted to morphine-equivalent doses (MEDs). Clinically meaningful events (CMEs) for 12 opioid-related symptoms were assessed by three ordinal measures: frequency, severity, and bothersomeness. Reduction of CMEs on Day 1 and number of patient-days with CMEs on Days 1–4 were examined. Results: Cumulative MEDs on Day 0, Day 1, and Days 1–4 were significantly lower in the parecoxib/valdecoxib group compared with the placebo group (P < 0.001). At the end of Day 1, parecoxib/valdecoxib-treated patients had significantly lower SDS scores (P < 0.02), a significantly reduced incidence of CMEs (P < 0.05), and significantly fewer patient-days with CMEs in Days 1–4 than placebo patients (P < 0.05). Patients in the parecoxib/valdecoxib group were less likely to have CMEs for multiple symptoms than those in the placebo group (P < 0.001). Conclusions: Treatment with parecoxib and valdecoxib significantly reduced the cumulative MED requirements, the incidence of opioid-related adverse effects, and patient-days with CMEs.

Troponin T-values provide long-term prognosis in elderly patients undergoing non-cardiac surgery.

Abstract: BACKGROUND: The aim of this study was to evaluate the significance of elevated postoperative Troponin T (TnT) levels in an elderly population undergoing non-cardiac surgery. METHODS: Five hundred a ...

Low-dose bupivacaine with sufentanil prevents hypotension after spinal anesthesia for hip repair in elderly patients

Abstract: Background: Hip fracture is common in the geriatric population. Patients in this group are often at high risk for perioperative complications from concurrent diseases. Conventional spinal anesthesia can be associated with hypotension but has a better postoperative outcome compared to general anesthesia. We judged that a reduced dose of bupivacaine in combination with sufentanil could give reliable blocks with minimal hypotension. Methods: Fifty elderly patients were randomized into two groups. The study group received spinal anesthesia as a combination of hyperbaric bupivacaine 7.5 mg and sufentanil 5 µg while the control group received hyperbaric bupivacaine 15 mg. The hemodynamic stability of the patients and the quality of the blocks were compared. Results: All patients had adequate duration of reliable blocks. More control group patients than study group patients required ephedrine due to hypotension. Conclusion: A reduced dose of hyperbaric bupivacaine (7.5 mg) in combination with sufentanil (5 µg) provides reliable spinal anesthesia for the repair of hip fracture in aged patients with few events of hypotension and little need for vasopressor support of blood pressure.

High-dose bupivacaine, levobupivacaine and ropivacaine in axillary brachial plexus block.

Abstract: Background: Racemic bupivacaine is clinically similar to levobupivacaine, or ropivacaine. The drugs were compared in brachial plexus block for the first time in the same randomized and double-blind study. Methods: In 90 patients scheduled for hand and forearm surgery, a perivascular axillary brachial plexus block was performed with 45 ml of 5 mg ml−1 of either racemic bupivacaine-HCl, levobupivacaine-HCl, or ropivacaine-HCl. Sensory (cold) and motor (hand clasp, and movement of elbow) block were scored, and the patient was interviewed in the postoperative evening and the following morning. Time to normal function of the arm was registered. Results: After similar onsets of sensory block, the sum of completely anaesthetized innervation areas of the four main nerves at 45 min was greater in the ropivacaine group than in the levobupivacaine group (P < 0.01). Simultaneously, complete motor block at the elbow was more frequent in the ropivacaine group (67%) than in the bupivacaine (47%) and levobupivacaine groups (30%) (P < 0.01). In the hand, the corresponding results were 83%, 77%, and 57%, respectively (NS). Two patients in the levobupivacaine and one in the ropivacaine group needed general anaesthesia. Mean duration of the blocks was similar in the bupivacaine, levobupivacaine and ropivacaine groups at 19.3 h, 19.5 h, and 17.3 h, respectively (NS). Two patients were dissatisfied with the long block duration. Conclusion: Ropivacaine-HCl 5 mg ml−1 produced slightly better sensory and motor block intensity than the same dose of levobupivacaine-HCl. General success in relation to surgery and in the duration of the blocks was similar in the three groups.

Bier's block; 100 years old and still going strong!

Abstract: In August 1908 Karl August Bier, Professor of Surgery in Berlin, described a new method of producing analgesia of a limb which he named 'vein anesthesia'. Bier first presented his new method of intravenous regional anesthesia (IVRA) at the 37th Congress of the German Surgical Society on 22 April, 1908, only 10 years after his significant communication on spinal anesthesia (1). His method, which now bears his name, consisted of occluding the circulation in a segment of the arm with two tourniquets and then injecting a dilute local anesthetic through a venous cut-down in the isolated segment. Bier had the good fortune to use procaine, the first safe injectable local anesthetic that had been synthesized by Einhorn in 1904.

Brain injury after adult cardiac surgery.

Abstract: Despite remarkable progress in surgical, cardiopulmonary bypass and anaesthetic techniques during the last three decades, brain damage remains an important complication of adult cardiac surgery. Effective brain protection strategies are already implemented today, but ongoing research is needed to meet the challenges faced in operating on increasingly old and disabled patients. The incidence of brain injury may be reduced by modifying the surgical procedure according to carotid duplex scanning and epiaortic echocardiography, by using techniques to reduce microembolization during cardiopulmonary bypass and by optimizing patient temperature during and after surgery. Increased knowledge will aid in choosing the best procedure or combination of procedures in each case to ensure that risks do not outweigh benefits.

Acute acalculous cholecystitis in critically ill patients.

Abstract: Background: Acute acalculous cholecystitis (AAC) is a serious complication of critical illness. We evaluated the underlying diseases, clinical and diagnostic features, severity of associated organ failures, and outcome of operatively treated AAC in a mixed ICU patient population. Methods: The data of all ICU patients who had operatively confirmed AAC during their ICU stay between 1 January 2000 and 31 December 2001 were collected from the hospital records and the intensive care unit's data management system for predetermined variables. Results: Thirty-nine (1%) out of 3984 patients underwent open cholecystectomy for AAC during the two-year period. Infection was the most common admission diagnosis, followed by cardiovascular surgery. The mean APACHE II score on admission was 25, and 64% of the patients had three or more failing organs on the day of cholecystectomy. The mean length of ICU stay before cholecystectomy was 8 days, and the mean total length of ICU stay was 19 days. Most patients (85%) received norepinephrine infusion, and 90% suffered respiratory failure before cholecystectomy. Hospital mortality was 44%. The non-survivors had higher Sequential Organ Failure Assessment (SOFA) scores on the day of cholecystectomy compared to the survivors (12.9 vs. 9.5, P = 0.007). Conclusion: Acute acalculous cholecystitis was associated with severe illness, infection, long ICU stay, and multiple organ failure. Mortality was related to the degree of organ failure. Prompt diagnosis and active treatment of AAC can be life-saving in these patients.

The use and safety of transoesophageal echocardiography in the general ICU -- a minireview.

Abstract: Background: The efficacy of transoesophageal echocardiography (TEE) has been evaluated predominantly in medical and cardiac surgical ICUs. This article reviews the pertinent literature and evaluates the impact of TEE in a general surgical ICU. Methods: Twenty studies on TEE in the ICU were evaluated for complications, indications, diagnostic, therapeutic, and surgical impact on patient management. Diagnostic impact was defined as identification of the underlying cardiovascular pathology, therapeutic impact as changes in patient management and surgical impact as indication for operative procedures. In addition, we reviewed the TEE reports and patient charts of 216 critically ill patients in a 16-bed multidisciplinary surgical ICU at our university hospital, who underwent a TEE for differential diagnosis of hemodynamic instability from July 1995 to December 1998 to assess the impact of TEE on patient management in a general surgical ICU. Results: The diagnostic, therapeutic and surgical impact in a total of 2,508 patients ranged from 44 to 99% (weighted mean 67.2%), 10–69% (36.0%), and 2–29% (14.1%), respectively. The complication rate was 2.6%, with no examination related mortality. In our series in a general surgical ICU, a diagnostic, therapeutic and surgical impact was inferred in 191 (88.4%), 148 (68.5%) and 12 (5.6%) patients, respectively. Adverse effects were observed in 5.6%. Conclusion: TEE is safe, well-tolerated and useful in the management of critically ill patients. This applies as well for hemodynamically unstable patients in a general surgical ICU.

Continuous popliteal sciatic nerve block for outpatient foot surgery--a randomized, controlled trial.

Abstract: Background: A major problem in outpatient foot surgery is severe postoperative pain that is not sufficiently treated by peroral analgesics. Methods: Sixty-three patients underwent foot surgery under spinal anesthesia. Immediately on conclusion of the operation, sciatic and saphenous nerve blocks were performed. The sciatic nerve was blocked in the popliteal fossa with 30 ml of ropivacaine 5 mg ml � 1 and a perineural catheter was passed through the cannula. The patients were randomized to receive either ropivacaine 2 mg ml � 1 (n ¼ 30) or saline (n ¼ 30) in the catheter through a disposable elastomeric pump with a fixed infusion rate of 5 ml h � 1 for 55 h. Results: Analgesia was excellent until 23 h 44 min (14 h 34 min) in the treatment group and 18 h 16 min (7 h) in the placebo group [mean (SD), P ¼ 0.07]. Thereafter, pain was significantly less in the treatment group on the first and second postoperative days (P ¼ 0.001). Sleep disturbances because of the pain in the foot were experienced by 25% of the treatment group on the first night at home and by 50% of the control group (P ¼ 0.29). There were no differences between the groups in their need for rescue opioid medication. None of the patients had any major problem with the catheter or pump, and none had any toxic effect referable to the technique. Conclusion: This randomized, double-blind study shows that continuous blockade of the sciatic nerve in the popliteal fossa reduces postoperative pain and has no untoward effects in a patient group known to experience severe pain after ambulatory surgery.

Age-related effects in the EEG during propofol anaesthesia.

Abstract: Background: Age-related differences in the spectral composition of the EEG in induction and emergence times, and in drug consumption during propofol anaesthesia were investigated. Methods: The EEGs of 60 female patients between 22 and 85 years of age were monitored continuously during standardized induction of anaesthesia with 2 mg of propofol kg−160 s−1. The EEGs were visually assessed in 20-s epochs according to a scale from A (awake) to F (very deep hypnosis). Visual EEG classifications, spectral parameters, and induction times were compared between different age groups. Additionally, data of 546 patients included in a multicentre study with 4630 patients (EEG monitor Narcotrend®, MT MonitorTechnik, Bad Bramstedt, Germany) were analyzed with regard to age-dependent changes of propofol consumption using target-controlled infusion (TCI). Results: During induction, patients older than 70 years reached significantly deeper EEG stages than younger patients, needed a longer time to reach the deepest EEG stage, and needed more time until a light EEG stage was regained. In patients aged 70 years and older, the total power, mainly in deep EEG stages, was significantly smaller due to a distinctly smaller absolute power of the delta frequency band. No single spectral parameter was able to reliably distinguish all EEG stages. During the steady state of anaesthesia, older patients needed less propofol for the maintenance of a defined stage of hypnosis than younger patients. Conclusion: Older patients differ from younger ones regarding the hypnotic effect of propofol and the spectral patterns in the EEG. For an efficient automatic assessment of the EEG during anaesthesia a multivariable approach accounting for age-effects is indispensable.

Impact of a critical care outreach team on critical care readmissions and mortality.

Abstract: Aims: The aim of a critical care outreach team is to facilitate discharges from critical care beds, educate ward staff in the management of deteriorating patients, facilitate transfer to critical care and reduce readmission rates to critical care. Although intuitively a good idea, there are few data to support outreach in terms of reducing the readmission rate to critical care and subsequent patient mortality. This retrospective observational study attempted to determine the change in the critical care readmission rate, an indicator of the quality of critical care, critical care mortality and in-hospital mortality following the introduction of a critical care outreach team in a major teaching hospital. Methods: A retrospective review of 1380 discharges from critical care was undertaken and the readmissions identified (n = 176). Readmission rate, mortality and other demographic data were compared between the pre and postoutreach periods. Results: Critical care mortality, in-hospital mortality and 30-day mortality were all reduced in the postoutreach period amongst readmissions to critical care. There was also a decease in the overall mortality of all patients admitted to critical care. There were no apparent causative factors for this reduction in mortality before and following outreach. Conclusions: There are many confounding factors in assessing the impact of outreach teams in hospitals. This study tentatively concludes that outreach teams may have a favourable impact on mortality rate amongst readmissions to critical care, but more data is needed from multicentre trials.

Comparison of 27‐gauge (0.41‐mm) Whitacre and Quincke spinal needles with respect to post‐dural puncture headache and non‐dural puncture headache

Abstract: Background: The incidence of headache after spinal anaesthesia has varied greatly between studies. We compared the incidence of postoperative headache in general and postdural puncture headache (PDPH) when using 27-gauge (G) (outer diameter 0.41 mm) Quincke and Whitacre spinal needles in ambulatory surgery performed under spinal anaesthesia. Methods: In a prospective, randomized study, 676 ASA physical status I–II day-case outpatients were given a spinal anaesthetic through either a 27-G (0.41 mm) Quincke or a 27-G (0.41 mm) Whitacre spinal needle. The incidence of any type of postoperative headache was assessed and the type of headache defined using a standardized questionnaire including PDPH criteria. The severity of the headache was defined using a 100-mm visual analogue scale. Results: For the final analysis, 529 patients were available (259 patients in the Quincke group and 270 patients in the Whitacre group). The overall incidence of postoperative headache was 20.0%, but the incidence of true PDPH was very low (1.51%). The incidence of PDPH in the Quincke group was 2.70%, while in the Whitacre group it was only 0.37% (P < 0.05). The overall incidence of non-dural puncture headache was 18.5% and did not differ between the study groups. Conclusions: True PDPH seldom occurs when a 27-G (0.41 mm) spinal needle is used, although postoperatively a non-specific headache is common. Using the 27-G (0.41 mm) Whitacre spinal needle further reduced the incidence of PDPH. Thus, we recommend routine use of the 27-G (0.41 mm) Whitacre spinal needle when performing spinal anaesthesia.

Postoperative cognitive dysfunction: true deterioration versus random variation.

Abstract: Background: Postoperative cognitive dysfunction (POCD) is a common complication, especially in the elderly. The aim of this study was to describe how variability in neuropsychological testing could lead to the detection of cognitive improvement and poor consistency of POCD between postoperative test sessions. Methods: In four published studies performed by the ISPOCD group, we included 2536 patients and 359 healthy controls. Cognitive function was assessed using neuropsychological tests preoperatively and at 7 days and 3 months thereafter, comparing the changes between those at baseline with those after surgery. Postoperative cognitive dysfunction was defined as a Z score greater than 2, and we also defined a corresponding improvement as a Z score less than −2. Consistency of POCD between postoperative test sessions was analyzed and we also assessed test–retest variability using data from healthy control subjects. Results: Improvement in cognitive function was found in 4.2–8.7% of patients after 1 week and in 5.0–7.8% after 3 months. The ratio between incidence of dysfunction and improvement varied in patients between 3.3 and 6.2 early after major surgery. Of those patients who displayed POCD at the 3-month test, 30–48% also had POCD at the previous test at 1 week. The test–retest reliability was between 0.56 and 0.90, except for the error score in Concept Shifting Test, where the values were 0.20 and 0.37. Conclusion: Variability in neuropsychological test data contributes to a low consistency between postoperative test sessions but it does not explain the detection of cognitive dysfunction after major surgery.