bluuebunny/crossref_metadata_2025 huggingface dataset:
Laryngeal papillomatosis with airway obstruction in an infant
Authors: Mikkelsen P. G.
Published: March 2003

Laryngeal papillomatosis in infants and children is a benign condition, but the location and a marked tendency for recurrence makes the disease both dangerous and troublesome. This case report deals with a little girl who had suffered hoarseness and wheezing since she was born. The diagnosis of laryngeal papillomatosis was made when she was 17 months old. By that time, the tumour had reached a size that necessitated a tracheotomy to secure the airway. The symptoms and differential diagnoses are discussed, and it is stressed that chronic hoarseness and wheezing sounds in infants and children should make a doctor suspect laryngeal papillomatosis. Laser treatment and anaesthetic management of small children with a compromised airway are discussed. As tracheal intubations and tracheotomy increase the risk of the disease spreading to the trachea and bronchi, an example is given of treating laryngeal papillomatosis with potassium titanyl phosphate (KTP) laser, using a laryngeal mask as an airway to avoid tracheal intubation. Whether this procedure can reduce the need to perform a tracheotomy in some of these small patients remains to be seen.
The influence of a dominating centre on a quantitative systematic review of granisetron for preventing postoperative nausea and vomiting
Authors: Kranke P. , Apfel C. C. , Eberhart L. H. , Georgieff M. , Roewer N.
Published: March 2003

Background: We performed a meta‐analysis on granisetron in the prevention of postoperative nausea and vomiting (PONV) and further investigated whether total results and the dose–response characteristics may be significantly affected by a single centre.

Methods: Systematically searched randomised controlled trials (RCT) using granisetron for the prevention of PONV after general anaesthesia were included in the analysis. The pooled relative risks (RR) and numbers needed to treat (NNT) with their corresponding 95%‐confidence intervals (CI) were calculated. For all centres, one dominating centre and other centres pooled, comparisons were performed according to all doses, low dose (≤20 μg/kg) and high dose (>20 μg/kg) granisetron.

Results: A total of 27 RCT with 2938 patients were included in the analysis. RR (CI) to suffer from PONV with granisetron when all comparisons were considered was 0.46 (0.39–0.54), 0.7 (0.6–0.81) and 0.34 (0.28–0.41) for all doses, low and high dose, respectively. RR of the dominating centre (1867 patients) were significantly better compared to the remaining centres (1071 patients), with 0.41 (0.34–0.49) and 0.60 (0.49–0.73), respectively. In the dominating centre low dose granisetron was ineffective with a RR of 0.84 (0.68–1.04), while high dose granisetron led to a strong decrease with a RR of 0.30 (0.26–0.36). In contrast, the RR of other centres pooled for low and high dose granisetron were comparable with 0.62 (0.49–0.79) and 0.56 (0.42–0.75), respectively.

Conclusions: Overall results and dose–response characteristics of meta‐analyses may be significantly altered by one dominating centre. Further, if data of a dominating centre do not appear to be valid for other centres, it may seem advisable to either exclude them from the analysis or to perform sub‐group analyses so that results without the data from the dominating centre are available.
The pressure at the lower inflexion point has no relation to airway collapse in surfactant‐treated premature lambs
Authors: Ingimarsson J. , Björklund L. J. , Larsson A. , Werner O.
Published: March 2003

Background: The lower inflexion point (LIP) on the inspiratory part of the pressure–volume (PV) loop has been suggested to be related to the pressure at which air spaces collapse. Our hypothesis is that airway collapse might instead be assessed from the upper inflexion point on the expiratory part of the PV‐loop (UIPexp), where lung volume starts to decrease significantly. We therefore examined whether there was a relation between LIP and UIPexp in premature surfactant‐treated lambs.

Methods: Ten lambs, at 119–141 days of gestational age, were delivered by cesarean section and given 200 mg/kg modified natural porcine surfactant before the first breath. The lambs were then connected to a ventilator and PV‐loops using airway pressures of 0–35–0 (ZEEP‐loop) and 5–35–5 cmH2O (PEEP‐loop) were obtained after lung recruitment at 15, 60 and 120 min after birth. From the loops, LIP, UIPexp, upper inflexion point of the inspiratory part of the loop (UIP insp), inspiratory capacity (IC) as well as inspiratory and expiratory maximal compliance of the respiratory system (Crsinsp and Crsexp) were calculated.

Results: The ZEEP‐loop showed a substantial hysteresis with a distinct LIP at 19±2 cmH2O (mean±SD), which was different (P<0.001) from UIPexp (9±2 cmH2O). The pressures at LIP and UIPexp were unrelated (r2=0.06). UIPinsp was located at 28±2 cmH2O. Crsinsp was 2.1±0.6 ml · cmH2O−1 · kg−1, which was lower (P<0.001) than Crsexp (2.8±0.6 ml · cmH2O−1 · kg−1). IC was 26±6 ml/kg. The PEEP‐loop had a minimal hysteresis with an expiratory part coinciding with that of the ZEEP‐loop.

Conclusion: In surfactant‐treated premature lambs the pressures at LIP and UIPexp are not related, showing that LIP does not indicate the pressure at which airways collapse.
Gentamicin dosing in critically ill patients
Authors: Hansen M. , Christrup L. L. , Jarløv J. O. , Kampmann J. P. , Bonde J.
Published: March 2003

Gentamicin is used worldwide in the treatment of serious infections in critically ill patients. The therapeutic efficacy of gentamicin is correlated to the peak serum concentration and the adverse effects to the trough concentrations. Information concerning the pharmacodynamics in critically ill patients is scarce, but pharmacokinetic data are available. A once‐daily dosage regimen has replaced multiple dosing of gentamicin in most intensive care units. No studies evaluating the superiority of either of these dosage recommendations in critically ill patients have ever been conducted. Based on 8 meta‐analyses performed addressing this issue on a wide range of patients and theoretical considerations, we consider a once‐daily dosage regimen feasible in critically ill patients. In septic patients the volume of distribution is significantly increased compared to normal patients, implying that the initial dose should be increased in this patient population. Additionally a general trend towards using higher loading doses (5–7 mg/kg) has been observed in USA, and the appropriateness of this dosing strategy is based on a large descriptive American study. We recommend that the initial dosage of gentamicin in critically ill hyperdynamic septic patients should be 7 mg/kg. Optimal and appropriate monitoring of the treatment with gentamicin in the critically ill patient is still an issue for further investigation. The treatment period with gentamicin should be short (3–5 days), bearing the pharmacological properties of aminoglycosides (small volume of distribution and poor tissue penetration) in mind. In patients with reduced renal function the initial dose of gentamicin should also be increased and maintenance dose reduced preferentially by prolonging the dosing intervals. However, the use of aminoglycosides in a high dose regimen in oliguric or anuric patients or patients who present with a rapidly decreasing renal function needs further consideration.
Effects of prilocaine and articaine on human leucocytes and reactive oxygen species in vitro
Authors: Günaydin B. , Demi̇ryürek A. T.
Published: March 2003

Background: The aim of this study was to investigate the ability of local anaesthetics to inhibit reactive oxygen and nitrogen species generated by either stimulated human leucocytes or cell‐free systems using luminol chemiluminescence (CL).

Methods: Free radical generation was stimulated in leucocyte assay by formyl‐methionyl‐leucyl‐phenylalanine (FMLP, 2 μM). In cell‐free experiments, hydrogen peroxide (H2O2) 3.5 mM, sodium hypochloride 5 μM, ferrous sulphate (FeSO4) 40 nM, peroxynitrite 50 nM and xanthine 0.1 mmol l−1 plus xanthine oxidase 0.25 U ml−1 were used to produce H2O2, hypochlorous acid (HOCl), hydroxyl radical, peroxynitrite and superoxide‐induced CL, respectively.

Results: Prilocaine inhibited FMLP‐induced CL in leucocytes (94±1%, at 1 mM), whereas articaine showed an activation (59±7%) at high concentration (1 mM) and inhibition (13±6%) at low concentration (0.1 mM). In cell‐free experiments, prilocaine (22±6%, at 1 mM) and articaine (85±1%, at 1 mM) caused concentration‐dependent inhibition in xanthine‐xanthine oxidase‐induced CL. Although articaine had no effect on H2O2‐induced CL, prilocaine significantly attenuated the H2O2 signal (97±0.3%, at 1 mM). Prilocaine (99±0.04%, 1 mM) and articaine (70±6%, 1 mM) markedly inhibited HOCl‐induced CL, whereas these drugs had no effect on FeSO4‐induced CL. Articaine inhibited peroxynitrite CL (63±6%, 1 mM), but prilocaine did not produce any depression on this signal.

Conclusion: Prilocaine interacted with superoxide, HOCl and H2O2, whereas articaine reacted with superoxide, HOCl, and peroxynitrite. The direct scavenging properties of these drugs might be involved in the inhibition observed in leucocyte assay and could provide experimental support for investigating the potential benefit of using these local anaesthetics in patients presenting pathologies associated with free radical reactions.
Postoperative reading speed does not indicate implicit memory in elderly cardiac patients after propofol and remifentanyl anaesthesia
Authors: Münte S. , Münte T. F. , Mitzlaff B. , Walz R. , Leuwer M. , Piepenbrock S.
Published: March 2003

Background: A recent study in young patients undergoing propofol‐alfentanil‐nitrous oxide anaesthesia demonstrated implicit memory for stories presented during operation using a postoperative reading speed task. In this study we investigated whether patients who tolerate only small amounts of anaesthetics are prone to develop implicit and explicit memories about intraoperative events.

Methods: Thirty patients with poor physical status (ASA III–IV) undergoing cardioverter defibrillator implantation were included in the study. Patients were premedicated with intravenous midazolam and anaesthesia was maintained using propofol and remifentanil infusions. During surgery one of two audio‐tapes containing two short stories was played to the patients. Reading speed for the stories played during surgery and two similar stories from the other tape was tested 4 h later. Explicit memory was tested at 4 h and 24 h after audiotape presentation using a structured interview and a forced‐choice recognition test pertaining to the story content. Thirty additional awake subjects served as controls.

Results: Although half of the patients seemed to be awake one or more times during the operation, no explicit memories of intraoperative events were reported. The forced‐choice recognition of the stories was at chance level. No effect on reading speed was found in either the patients or the control subjects.

Conclusions: The possible reasons for reduced explicit and implicit memory performance in elderly patients are age and poor physical status of the patients and the modality change between study and test phases. A non‐anaesthetised control group of the same age and physical status should therefore be included in all studies of implicit memory.
Comparison of two video‐assisted techniques for the difficult intubation
Authors: Biro P. , Weiss M.
Published: March 2003

Background: Two recently developed video‐optical intubation devices, the video‐optical intubation stylet (VOIS) and the angled video intubation laryngoscope (AVIL) were compared for intubation times and success rate in a simulated difficult tracheal intubation setting.

Methods: Thirty anaesthetists were asked to perform 5 intubation attempts with both techniques. Intubation times were recorded and the subjective degree of difficulty and preference for each technique were requested.

Results: Intubation time with the VOIS was shorter (17.4±6.8 s) than with the AVIL (22.8±13.4 s; P=0.0001). Four of the 150 intubation attempts with the AVIL were scored as unsuccessful, due to prolonged intubation time (>60 s). The estimated degree of difficulty was not significantly different.

Conclusion: In conclusion, both video‐assisted intubation devices, the video‐optical intubation stylet and the angled video intubation laryngoscope, can be considered to be simple and effective tools which facilitate tracheal intubation and which require only brief instruction and training.
Postoperative analgesia by combined continuous infusion and patient‐controlled epidural analgesia (PCEA) following hip replacement: ropivacaine versus bupivacaine
Authors: Bertini L. , Mancini S. , Di Benedetto P. , Ciaschi A. , Martini O. , Nava S. , Tagariello V.
Published: March 2003

Background: Ropivacaine is a new local anaesthetic, which compared to bupivacaine is less toxic and shows greater sensory and motor block dissociation. We hypothesised that treatment of postoperative pain with a combined regimen of continuous epidural infusion and Patient‐Controlled Epidural Analgesia (PCEA) using ropivacaine could have given better results compared with those we had obtained using bupivacaine.

Methods: Patients undergoing total hip replacement were randomly assigned to two groups. They received epidural analgesia for postoperative pain treatment using ropivacaine, 2 mg  ·  ml−1 or bupivacaine 2 mg  ·  ml−1. Both drugs were administered as a constant infusion of 6 ml  ·  h−1 supplemented by PCEA bolus doses of 2 ml. Patients in both groups received morphine intravenously on demand from a patient‐controlled analgesia (PCA) device. An independent observer recorded pain scores, intensity of motor block and morphine consumption at regular intervals during the first 24 h after surgery.

Results: Fifty‐one patients were evaluated. Ropivacaine and bupivacaine, in similar amounts, provided similar results assessed as adequate to very good postoperative analgesia, whereas motor block was significantly more intense in patients treated with bupivacaine.

Conclusions: Despite similar analgesic effects, epidural infusion of ropivacaine combined with PCEA provides higher patient satisfaction than equal doses of bupivacaine due to lack of motor block.
Caudal bupivacaine‐tramadol combination for postoperative analgesia in pediatric herniorrhaphy
Authors: Senel A. C. , Akyol A. , Dohman D. , Solak M.
Published: March 2003

Background: Administration of bupivacaine caudally has been used for postoperative analgesia after urogenital, rectal and lower abdominal surgery in children. Caudal opioids may offer analgesic advantages over bupivacaine alone but have been associated with side effects such as respiratory depression. Tramadol is an analgesic assumed to lack a respiratory depressant effect and has been shown to provide effective, long‐lasting analgesia after epidural administration in adults and children. The aim of this study was to determine whether the addition of tramadol to bupivacaine caudally prolongs the duration of analgesia compared with bupivacaine alone, with respect to side effects, and whether caudal tramadol alone provides satisfactory analgesia.

Methods: Sixty boys, aged 12–84 months, undergoing unilateral herniorrhaphy, were allocated randomly to three groups. Children in group B received 0.25% plain bupivacaine 1 ml kg−1, group BT received an identical local anesthetic dose mixed with tramadol 1.5 mg kg−1 and group T received caudal tramadol 1.5 mg kg−1 in 0.9% sodium chloride in the same total volume (1 ml kg−1). Pain and demeanour assessments were made 1, 2, 3, 4, 6, 12 and 24 h after recovery from anesthesia with reference to a three‐point scale.

Results: Analgesia time (time between caudal injection and first administration of analgesic) in group BT (13.5±2.2 h) was significantly longer than in the other two groups (P<0.05). In group T, more patients required additional analgesia after surgery than in the other two groups (P<0.05). Pain scores in the three groups were similar up to 4 h after operation but the mean score in group T was higher than groups B and BT 4 and 6 h after operation (P<0.05). Significantly more patients who had received caudal bupivacaine alone or with tramadol had lower pain and demeanour scores during the first 24 h after operation compared with those in the tramadol group.

Conclusion: Caudal administration of bupivacaine with the addition of tramadol resulted in superior analgesia with a longer period without demand for additional analgesics compared with caudal bupivacaine and tramadol alone without an increase of side effects.
Efficacy and safety of patient‐controlled opioid analgesia for acute postoperative pain
Authors: Walder B. , Schafer M. , Henzi I. , Tramèr M. R.
Published: March 2003

Background: The usefulness of intravenous patient‐controlled analgesia (PCA) with opioids for postoperative analgesia is not well defined.

Methods: We systematically searched (MEDLINE, EMBASE, Cochrane Library, bibliographies, any language, to January 2000) for randomised trials comparing opioid‐based PCA with the same opioid given intramuscularly, intravenously, or subcutaneously. Weighted mean differences (WMD) for continuous data, relative risks (RR) and numbers‐needed‐to‐treat (NNT) for dichotomous data were calculated with 95% confidence intervals (CI) using fixed and random effects models.

Results: Data from 32 trials were analysed: 22 (1139 patients) were with morphine, five (682) with pethidine, three (184) with piritramide, one (47) with nalbuphine and one (20) with tramadol. In three morphine and one pethidine trial (352 patients), more patients preferred PCA (89.7% vs 65.8%, RR 1.41 (95%CI 1.11 to 1.80), NNT 4.2). Combined dichotomous data on pain intensity and relief, and the need for rescue analgesics from eight morphine, one pethidine, one piritramide, and one nalbuphine trial (691 patients), were in favour of PCA (RR 1.22 (1.00 to 1.50), NNT 8). In two morphine trials (152), pulmonary complications were more frequently prevented with PCA (100% vs 93.3%, RR 1.07 (1.01 to 1.14), NNT 15). There was equivalence for cumulative opioid consumption, pain scores, duration of hospital stay, and opioid‐related adverse effects.

Conclusion: These trials provide some evidence that in the postoperative pain setting, PCA with opioids, compared with conventional opioid treatment, improve analgesia and decrease the risk of pulmonary complications, and that patients prefer them.
Improved recovery after music and therapeutic suggestions during general anaesthesia: a double‐blind randomised controlled trial
Authors: Nilsson U. , Rawal N. , Uneståhl L. E. , Zetterberg C. , Unosson M.
Published: March 2003

Purpose: This study was designed to determine whether music or music in combination with therapeutic suggestions in the intra‐operative period under general anaesthesia could improve the recovery of hysterectomy patients.

Methods: In a double‐blind randomised clinical investigation, 90 patients who underwent hysterectomy under general anaesthesia were intra‐operatively exposed to music, music in combination with therapeutic suggestion or operation room sounds. The anaesthesia was standardised. Postoperative analgesia was provided by a patient‐controlled analgesia (PCA). The pain scores were recorded by means of a visual analogue scale. Nausea, emesis, bowel function, fatigue, well‐being and duration of hospital stay were studied as outcome variables.

Results: On the day of surgery, patients exposed to music in combination with therapeutic suggestions required less rescue analgesic compared with the controls. Patients in the music group experienced more effective analgesia the first day after surgery and could be mobilised earlier after the operation. At discharge from the hospital patients in the music and music combined with therapeutic suggestion group were less fatigued compared to the controls. No differences were noted in nausea, emesis, bowel function, well‐being or length of hospital stay between the groups.

Conclusion: This double‐blind study has demonstrated that intra‐operative music and music in combination with therapeutic suggestions may have some beneficial effects on postoperative recovery after hysterectomy. Further controlled studies are necessary to confirm our results.
Tracheal intubation through the intubating laryngeal mask in patients with unstable necks
Authors: Asai T. , Shingu K.
Published: March 2003

Background: In patients with unstable necks, the neck should be stabilized during induction of anaesthesia, but this may make tracheal intubation difficult. Awake intubation may produce straining, which could be detrimental to the unstable neck.

Methods: We studied 20 patients with unstable necks to examine the efficacy of insertion of the intubating laryngeal mask under conscious sedation (to minimize the possibility of losing a patent airway and to facilitate fibrescope‐aided intubation) followed by tracheal intubation through the laryngeal mask after induction of anaesthesia (to reduce stress response to intubation). After the patient had been sedated with midazolam (up to 5 mg) and fentanyl (up to 100 μg), the intubating laryngeal mask was inserted. General anaesthesia was then induced with sevoflurane and tracheal intubation attempted.

Results: In all patients, tracheal intubation through the laryngeal mask succeeded without airway obstruction. Neither insertion of the mask under conscious sedation nor tracheal intubation after induction of anaesthesia caused straining, and only two patients moved upper extremities at intubation. Insertion of the laryngeal mask did not significantly alter blood pressure or heart rate. Tracheal intubation significantly increased blood pressure and heart rate, but the increase was considered to be small.

Conclusions: In the patient with an unstable neck with a low risk of pulmonary aspiration, insertion of the intubating laryngeal mask while the patient is sedated may minimize difficulty in obtaining a patent airway before tracheal intubation and may facilitate a fibrescope‐aided tracheal intubation; subsequent induction of anaesthesia before tracheal intubation may minimize stress response to intubation.
Effects of combined methohexitone‐remifentanil anaesthesia in electroconvulsive therapy
Authors: Andersen F. A. , Årsland D. , Holst‐Larsen H.
Published: March 2003

Background: Methohexitone is widely used to provide anaesthesia for patients undergoing electroconvulstive therapy (ECT). Short seizure duration, high blood pressures (BP) and heart rates (HR) are usual in elderly patients. In this study, elderly patients undergoing ECT received low dose methohexitone with remifentanil or methohexitone alone and motor seizure duration, haemodynamic response and recovery time were compared.

Methods: Ten patients, of mean age 74.3 years, were enrolled in this double‐blind, randomised crossover trial, receiving a total of 38 ECTs. Each patient was given the following two i.v. regimens in random order: A) methohexitone 0.5 mg kg−1 combined with remifentanil 1.0 μg kg−1 and B) methohexitone 0.75 mg kg−1. Additional methohexitone was given, if needed, until loss of consciousness, and then suxamethonium 1.0 mg kg−1 for muscular paralysis.

Results: Mean motor seizure duration was significantly longer with methohexitone‐remifentanil (37.6 s (SD 12.0)) than with methohexitone alone (27.1 (SD11.5)) (P=0.0009). Recovery time, time to spontaneous breathing, peak postictal changes in BP and HR were similar with both regimens.

Conclusion: A reduced dose of methohexitone combined with remifentanil allows prolonged duration of motor seizures in ECT. We conclude that low dose methohexitone combined with a short‐acting opioid is a reasonable alternative for elderly patients undergoing ECT, and for other patients with short seizure duration.
Being awake intermittently during propofol‐induced hypnosis: A study of BIS, explicit and implicit memory
Authors: Barr G. , Anderson R. E. , Öwall A. , Jakobsson J. G.
Published: March 2003

Background: Being awake during anaesthesia is a serious complication. An anaesthetic depth monitor must discriminate in real time between wakefulness and unconsciousness. The present study created a period of wakefulness during propofol‐induced hypnosis. Bispectral index (BIS), explicit and implicit memories of the awake period were investigated.

Methods: Ten volunteers were studied. The calculated brain concentration of a target controlled infusion of propofol was increased until loss of response (LOR) to verbal command and then propofol was stopped. When fully awake, volunteers were presented with a picture, sound and smell. Propofol infusion was restarted until LOR and then ceased. BIS and the calculated brain concentration of propofol were recorded every minute. A structured interview was conducted for explicit memories after awakening and for explicit as well as implicit memories the day after.

Results: Median BIS‐index for the transition between awake and asleep and vice versa differed significantly. It was not possible, however, to establish any threshold value or zone for discriminating between wakefulness and LOR due to the large inter‐individual variations in BIS‐index. No volunteer could explicitly recall any of the stimuli presented during the period of wakefulness.

Conclusion: The BIS‐index decreases with increasing sedation but because of the large individual variations, the real‐time BIS‐index for the individual subject cannot reliably discriminate wakefulness from unconsciousness during propofol infusion. Propofol causes such profound amnesia that lack of postoperative recall does not assure that episodes of awareness have not occurred during propofol‐induced hypnosis.
Time course of changes in jugular venous oxygen saturation during hypothermic or normothermic cardiopulmonary bypass in patients with diabetes mellitus
Authors: Kadoi Y. , Saito S. , Goto F. , Someya T. , Kamiyashiki S. , Fujita N.
Published: March 2003

Background: Preexisting diabetic mellitus is a risk factor determining postoperative neurological disorders. The present study assesses the effects of normothermic and hypothermic cardiopulmonary bypass (CPB) on jugular venous oxygen saturation (SjvO2)in patients with preexisting diabetic mellitus.

Methods: Sixteen diabetic patients who underwent elective coronary artery bypass grafting surgery were randomly divided into two groups: Group DN (n=8, diabetic patients) underwent normothermic CPB (>35°C), and group DH (n=8, diabetic patients) underwent hypothermic CPB (32°C). Controls were 16 age‐matched non‐diabetic patients (normothemic group, CN: n=8; hypothemic group, CH: n=8). A 4.0 F fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to continuously monitor SjvO2 values. Hemodynamic parameters and arterial and jugular venous blood gases were measured seven times.

Results: Cerebral desaturation, which was defined as SjvO2 values below 50%, was observed during normothermic CPB in diabetic patients (at the onset of CPB: 46±3%, at 20 min after onset of CPB: 49±3%, means±SD, respectively). No cerebral desaturation occurred in diabetic and control patients during hypothermic CPB.

Conclusions: Patients with preexisting diabetes mellitus experienced cerebral desaturation during normothermic CPB.
Anticoagulation with hirudin for continuous veno‐venous hemodialysis in liver transplantation
Authors: Saner F. , Hertl M. , Broelsch C. E.
Published: March 2003

Postoperative encephalopathy after orthotopic liver transplantation can be difficult to diagnose. We report a case of heparin‐induced thrombocytopenia in a liver transplant patient who had seizures. Due to poor liver function the patient developed hepatorenal syndrome requiring continuous veno‐venous hemodialysis (CVVHD). Initially we used heparin as the anticoagulant. After the diagnosis of heparin‐induced thrombocytopenia (HIT) was made, we switched to r‐hirudin. No serious side effects, e.g. bleeding or immune sensitization, were seen.
Neurologic sequelae after caesarean section
Authors: Rorarius M. , Suominen P. , HaanpÄÄ M. , Puura A. , Baer G. , Pajunen P. , Tuimala R.
Published: March 2003

Background: Because pregnancy increases the sensitivity of nervous tissue to local anaesthetics, pregnant patients may be at higher risk of developing neurologic deficits after spinal block than non‐pregnant patients. Therefore, we evaluated prospectively the incidence and type of neurologic symptoms after spinal anaesthesia with hyperbaric bupivacaine for caesarean section.

Methods: In this prospective follow‐up study we recorded neurologic complications during anaesthesia and postoperatively until discharge from the hospital of 219 patients, who underwent caesarean section under spinal anaesthesia with hyperbaric bupivacaine (5 mg/ml, mean 13 mg). The patients filled in a questionnaire on the first and fifth postoperative days. In the case of complaints typical of neurologic symptoms they were checked first by the anaesthesiologist and, in the case of persistent symptoms, afterwards additionally by a neurologist.

Results: Twenty‐six of 219 patients were not included in the further evaluation because of incomplete return of their questionnaires. Seventeen mothers (8.8%) complained of transient neurologic symptoms (TNSs), lasting mostly 1–2 days, in the buttocks and/or legs during the first three postoperative days. Eleven patients (5.7%) complained of postdural puncture headache. Two patients (emergency caesarean section because of protracted labour in one and elective caesarean section because of previous caesarean section in the other) complained of persisting pain or sensory abnormalities. Neither of them felt paraesthesia during lumbar puncture.

Conclusion: Women after caesarean section under a spinal block seem to suffer more often from TNSs than non‐pregnant women. The conclusions are, however, uncertain since we had no control group operated on under other than spinal anaesthesia. The persisting neurologic symptoms in two patients might also be due to the obstetric procedure itself. To find out about the validity and possible underlying causes of our results, we need randomised studies with control groups receiving epidural or general anaesthesia.
Preoperative rectal diclofenac versus paracetamol for tonsillectomy: effects on pain and blood loss
Authors: Schmidt A. , Björkman S. , Åkeson J.
Published: March 2003

Background:Diclofenac is widely used for postoperative analgesia but the perioperative safety of this drug is controversial because of its effect on platelet aggregation, which might increase blood loss. In a prospective investigator‐blinded study the effects of diclofenac and paracetamol on pain and blood loss were compared in patients undergoing tonsillectomy.

Method:

Ninety patients were randomised to receive rectal diclofenac 0.65–1.0 mg · kg−1or paracetamol 13–20 mg · kg−1preoperatively. Ten patients were excluded after randomisation. Pain was evaluated postoperatively by means of the visual analogue scale and by recording the use of pethidine for rescue analgesia. Perioperative blood loss was estimated from measured intraoperative blood loss; use of drugs to achieve haemostasis, and the incidence of reoperations.

Results:Anaesthetic or surgical managements did not differ between the groups, but a significantly longer period of surgery was found in the diclofenac group, 32±16 vs. 25±11 min (P=0.024). Pain scores or pethidine consumption were not significantly different between the groups. Intraoperative blood loss was significantly larger in the diclofenac group, 1.9 (1.1–3.1) vs. 1.1 (0.7–2.0) ml · kg−1(P=0.007).

Conclusion:Preoperative rectal diclofenac offers no advantage over paracetamol with respect to postoperative analgesia in tonsillectomy patients but increases intraoperative blood loss.
Ventilation–perfusion distributions in different porcine lung injury models
Authors: Neumann P. , Hedenstierna G.
Published: March 2003

Background: Acute lung injury is characterized by hypoxemia which may be caused by hypoventilation, ventilation–perfusion (V˙A/Q˙) mismatch, intrapulmonary shunting and oxygen diffusion impairment. The multiple inert gas elimination technique (MIGET) allows analysis of these four causes of hypoxemia and is therefore the most comprehensive approach to investigate blood gas abnormalities. Using MIGET, we studied whether specific patterns of gas exchange abnormalities occur in different lung injury models and whether gas exchange abnormalities can be related to pathogenic aspects of lung injury.

Methods: Lung injury was induced with oleic acid injection, endotoxin infusion or repeated lung lavage in groups of 6 mechanically ventilated pigs.

Results: PaO2 decreased and PaCO2 increased significantly in all three lung injury models, but gas exchange was more impaired in the oleic acid and lavage, as compared to the endotoxin group. Shunt was the major cause of hypoxemia in our lung injury models, whereas V˙A/Q˙ mismatch contributed to venous admixture only after oleic acid injection and lung lavage. Oxygen diffusion limitation was not observed. Although alveolar ventilation was maintained after induction of lung injury, hypercapnia developed due to an increase of the ventilatory mean towards higher V˙A/Q˙ ratios, increased shunt and increased carbon dioxide production.

Conclusions: Shunt and ventilation–perfusion mismatch fully explain the gas exchange disturbances observed in our lung injury models. Although V˙A/Q˙ distributions can be related to pathogenic aspects of the three study groups, we did not observe specific V˙A/Q˙ patterns which allow diagnosis of the type of lung injury from a recovered V˙A/Q˙ distribution.
Circulating neutrophils exhibit enhanced apoptosis associated with mitochondrial dysfunctions after surgery under general anaesthesia
Authors: Delogu G. , Moretti S. , Famularo G. , Antonucci A. , Signore L. , Marcellini S. , Lo Bosco L. , De Simone C.
Published: March 2003

Background: Evidence suggests that apoptosis plays a main role in the postoperative changes detected in the polymorphonuclear neutrophil (PMN) population. Furthermore, recent studies have demonstrated that mitochondrial alterations constitute critical events of the apoptotic cascade. In this study we investigated whether apoptosis among neutrophils taken from patients undergoing surgical trauma could be associated with perturbation of mitochondrial transmembrane potential (ΔΨm) and/or exaggerated production of mitochondrial reactive oxygen species (ROS).

Methods: Twenty‐seven patients undergoing elective surgery under general anaesthesia were enrolled in the study. Peripheral blood samples were drawn one day before the operation and at 12 and 24 h after surgery. Apoptosis rate was assessed by staining neutrophils with 7‐amino‐actinomycin D (7‐AAD) and by analysis by a FACScan flow cytometer. In order to evaluate ΔΨm, cells were exposed to 3,3‐dihexyloxacarbocyanine iodide [DiOC6(3)]; intracellular ROS was measured by means of hydroethidine (HE) and 2,7‐diclorofluorescein diacetate (DCFH‐DA), followed by analysis on a cytofluorometer.

Results: At 12 h following surgery we observed a significantly (P<0.05) increased frequency of apoptotic PMNs compared to that preoperatively (30.79±3.68% vs 7.40±0.69%). At this same time‐point, the rate of neutrophils stained with HE, DCFH‐DA and [DiOC6(3)] were significantly (P<0.05) higher compared to baseline (51.05±5.44%, 50.58±5.84% and 55.31±4.33% vs 20.17±2.38%, 19.59±2.03 and 25.43±2.71% respectively). Overall measurements returned to the preoperative values 24 h after surgery.

Conclusion: These data suggest that surgery under general anaesthesia triggers in the immediate postoperative period pathways of PMN accelerated apoptosis associated with significant alterations in mitochondrial function.
Monitoring of end‐tidal carbon dioxide partial pressure changes during infrarenal aortic cross‐clamping: a non‐invasive method to predict unclamping hypotension
Authors: Boccara G. , Jaber S. , Eliet J. , Mann C. , Colson P.
Published: March 2003

Background: To assess the variations in end‐tidal CO2 in response to aortic cross‐clamping and the relationship with systolic arterial pressure (SAP) changes induced by unclamping.

Methods: Thirty‐three patients undergoing infrarenal aortic abdominal aneurysm repair by aorto‐aortic prothetic bypass were prospectively studied. All patients were anesthetized with iv midazolam (0.05 mg · kg−1), thiopentone (3–5 mg · kg−1), fentanyl (5 μg · kg−1), pancuronium (0.1 mg · kg−1) and the maintainance of anesthesia used was 1–1.5% end‐tidal isoflurane and iv fentanyl. The perioperative management was standardized. End‐tidal CO2 and SAP were measured 5 min before (Pre‐XAA), 15 min after infrarenal aortic cross‐clamping (XAA), 5 min before (Pre‐UXAA) and immediately after unclamping (UXAA).

Results: A total of 16 (48.5%) from 33 patients presented decrease in SAP following aortic unclamping, and 13 out of these patients had arterial hypotension defined as SAP <90 mmHg. End‐tidal CO2 variation (PreXAA–PreUXAA) induced by aortic clamping was correlated with SAP variation (PreUXAA–UXAA) induced by unclamping (r=0.763; P=0.0001). An end‐tidal CO2 reduction above 15% after aortic cross‐clamping was found to have a 100% sensitivity to detect a SAP decrease greater than 20% after unclamping, with a 100% specificity and a negative predictive value of 1.0. Complete aortic occlusion duration was not correlated to SAP unclamping variation (ΔSAP). Intraoperative characteristics (fluid loading, hematocrits, urinary output) were comparable, although blood loss was higher in patients experiencing ΔSAP>20%.

Conclusions: End‐tidal CO2 variation monitoring during aortic cross‐clamping may provide a reliable and non‐invasive method to predict unclamping hypotension. When the aortic clamp was released, systolic hypotension (>20%) occurred in those subjects who had a decrease in end‐tidal CO2 greater than 15% during aortic cross‐clamping.
Perioperative response of leptin and the tumor necrosis factor alpha system in morbidly obese patients. Influence of cortisol inhibition by etomidate
Authors: Montalbán C. , Del Moral I. , García‐Unzueta M. T. , Villanueva M. A. , Amado J. A.
Published: March 2003

Background: Leptin, tumor necrosis factor alpha (TNFα) and soluble TNFα receptors are secreted by the adipose tissue. Surgery induces a complex cytokine and neurohormonal response. The aim of our study was to investigate the perioperative response of leptin and the TNFα system in morbidly obese patients submitted to gastroplasty, and the possible involvement of cortisol in their responses.

Methods: Serum cortisol, adrenocorticotropic hormone (ACTH), leptin, TNFα and soluble TNFα receptor I were measured in 22 morbidly obese women (11 anesthetized with thiopental and 11 with etomidate, a well known inhibitor of cortisol synthesis). Samples were collected before anesthesia induction, just before surgical incision, and 2, 4, 6, 12, 24 and 48 h after the start of surgery.

Results: Baseline serum leptin correlated with body mass index (r=0.567, P=0.007). Baseline serum leptin and TNFα were higher than normal. Cortisol release was inhibited in the etomidate group with a subsequent higher stimulation of ACTH release. A statistically significant decrease in serum leptin levels was observed in both groups at 2, 4, 6 and 48 h, compared with basal values. A similar decrease in serum TNFα levels was observed in both groups, but the decrease reached significance only in the etomidate group. Serum soluble TNFα receptor I did not decrease. No differences were found between the two groups in leptin, TNFα or soluble TNFα receptor I concentrations at any time.

Conclusion: Serum leptin and TNFα levels decrease in obese patients during gastroplasty. Transitory inhibition of cortisol release does not alter this response.
Epidural fentanyl markedly improves thoracic epidural analgesia in a low‐dose infusion of bupivacaine, adrenaline and fentanyl
Authors: Niemi G. , Breivik H.
Published: March 2003

Background: The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief, and side effects when removing fentanyl from an optimally titrated epidural infusion consisting of bupivacaine, fentanyl and adrenaline.

Methods: A prospective, randomized, double‐blind, crossover study was carried out in 20 patients after major upper abdominal surgery requiring a large longitudinal incision. Patients with only mild pain when coughing during thoracic epidural infusion of about 10 ml per hour of bupivacaine 1 mg · ml−1, fentanyl 2 μg · ml−1, and adrenaline 2 μg · ml−1 were included. On the 1st and 2nd postoperative days, each patient was given a double‐blind epidural infusion, at the same rate, with or without fentanyl. The effects were observed for 6 h or until pain when coughing became unacceptable in spite of rescue analgesia. Rescue analgesia consisted of up to two patient‐controlled epidural bolus injections (4 ml) per hour and intravenous morphine if necessary.

Results: Main outcome measures, i.e. pain intensity when coughing and at rest, increased (P<0.001) when fentanyl (19.2±5.2 μg · h−1) was omitted from the epidural infusion: after 6 h pain intensity when coughing had increased to unacceptable levels in spite of increased consumption of rescue bupivacaine and adrenaline (P<0.001). Within 15–20 min after restarting the triple epidural mixture with fentanyl, pain intensity was again reduced to mild pain when coughing.

Conclusions: A low dose of epidural fentanyl (20 μg · h−1) markedly improved the pain‐relieving effect of bupivacaine and adrenaline infused epidurally at a thoracic level after major upper abdominal surgery. This dose of fentanyl is much too small to relieve severe dynamic pain when given systemically. Therefore, this study indirectly supports the view that a low‐dose thoracic epidural infusion of fentanyl has a spinal analgesic site of action.
Lung recruitment at birth does not improve lung function in immature lambs receiving surfactant
Authors: Björklund L. J. , Ingimarsson J. , Curstedt T. , Larsson A. , Robertson B. , Werner O.
Published: March 2003

Background: In mature animals with surfactant deficiency induced by lung lavage, the therapeutic effect of exogenous surfactant is enhanced by a lung recruitment maneuver. We then tested whether a lung recruitment maneuver at birth immediately before surfactant treatment would improve lung function also in preterm lambs with surfactant deficiency due to immaturity.

Methods: Ten newborn lambs with a gestational age of 127 days were randomized to receive surfactant either before the first breath or immediately after a lung recruitment maneuver consisting of five sustained inflations of 8, 16 or 32 ml/kg. Functional residual capacity was measured by sulfur hexafluoride washout, and inspiratory capacity as well as maximal compliance were obtained from a static expiratory pressure–volume curve after the lungs had been inflated to 35 cm H2O. In addition, blood gases were obtained. Measurements were made at 15, 45, 175, 135, 170 and 230 min after birth. Post mortem histological examinations of the lungs were performed in a blinded fashion.

Results: The lung recruitment maneuvers did not improve oxygenation. Inspiratory capacity, static compliance and functional residual capacity at 4 h, as well as post mortem intrapulmonary air volume, had an inverse relation to the size of inflations given at birth. There was also a negative correlation between size of inflations at birth and response to surfactant therapy, as assessed by lung microscopy.

Conclusion: Lung recruitment at birth does not improve the response to surfactant in immature lambs, but may instead have an adverse effect on lung function and morphology.
Dose–response relationship of propofol on mid‐latency auditory evoked potentials (MLAEP) in cardiac surgery
Authors: Palm S. , Linstedt U. , Petry A. , Wulf H.
Published: March 2003

Background: Propofol‐sufentanil anaesthesia has become popular during cardiac surgery for its titrability and short recovery time. Avoidance of awareness is a major goal during cardiac surgery. We therefore investigated the dose–response relationship of propofol and cortical responses (mid‐latency auditory evoked potentials, MLAEP).

Methods: One hundred patients undergoing cardiac surgery were investigated. Basic anaesthesia was performed with sufentanil (4.5 μg kg−1 h−1) / flunitrazepam (9 μg kg−1 h−1) infusion (control group); the other groups received in addition a loading dose of propofol 2 mg kg−1 and a maintainance infusion of 1–3.5 mg kg−1 h−1. MLAEP were evaluated by using Pa/Nb‐amplitudes and Nb‐latencies. Haemodynamics were monitored by ECG, arterial blood pressure and cardiac function with pulmonary artery catheterization.

Results: In the control group, median amplitude of MLAEP decreased by 50% with a wide range, but were detectable in >90% of patients throughout surgery. Propofol suppressed amplitude Pa/Nb of MLAEP dose dependently. With 3.5 mg kg−1 h−1 amplitudes disappeared in >40% of patients throughout cardiac surgery. Median Nb‐latencies increased in the control group from 44 to a range from 50 to 60 ms. In groups with propofol >2 mg kg−1 h−1, Nb‐latencies, detectable in the patients without complete suppression of MLAEP, increased to median 60 ms. Haemodynamic parameters and cardiac function did not differ among the groups. The use of vasopressors was not increased even with the highest propofol dose used.

Conclusion: The dose–response effect of propofol on auditory evoked potentials reveals that combining a loading dose of 2 mg kg−1 with a consecutive infusion of 3.5 mg kg−1 h−1 significantly suppresses MLAEP during cardiac surgery. Thus, auditory information may not be processed and awareness with recall becomes unlikely.
Preoperative blood pressure and intraoperative hypothermia during lower abdominal surgery
Authors: Kasai T. , Hirose M. , Matsukawa T. , Takamata A. , Kimura M. , Tanaka Y.
Published: March 2003

Background: Preoperative factors including age and body habitus affect intraoperative hypothermia during general anesthesia. We hypothesized that preoperative blood pressure also plays a contributory role in the induction of intraoperative hypothermia.

Methods: We evaluated the effect of preoperative systolic blood pressure (SBP) on core temperature during lower abdominal surgery under general anesthesia. In 36 female patients under 65 years of age, patients with a preoperative SBP of 140 mmHg or greater upon arrival in the operating theater were assigned to the high SBP group (n=18), while those with SBP below 140 mmHg were assigned to the normal SBP group (n=18). Anesthesia was maintained with isoflurane and nitrous oxide combined with epidural buprenorphine, and routine thermal care was provided intraoperatively.

Results: There were no significant differences in age, height or weight between the two groups. Tympanic membrane temperature in the normal SBP group started to decrease significantly from 15 min after induction of anesthesia compared to that in the high SBP group, and continued to decrease further at two hours after induction. Vasoconstriction threshold, determined to be tympanic membrane temperature at the time when a forearm minus finger skin surface gradient exceeded 0 °C, was significantly higher in the high SBP group than in the normal SBP group.

Conclusion: These results suggest that preoperative SBP has some preventive effect on the decrease in intraoperative core temperature during lower abdominal surgery under general anesthesia.