bluuebunny/crossref_metadata_2025 huggingface dataset:
Postoperative epidural analgesia in children after major orthopaedic surgery
Authors: Løvstad R. Z. , Støen R.
Published: March 2003

Background: The study was performed in order to improve postoperative pain management in children after major orthopaedic surgery. Two different anaesthetic techniques (sevoflurane‐low fentanyl and propofol‐higher fentanyl) and two different epidural mixtures (bupivacaine 1.5 mg ml−1 and adrenaline 2 μg ml−1 compared with bupivacaine 1 mg ml−1, adrenaline 2 μg ml−1 and fentanyl 2 μg ml−1) were investigated with regard to postoperative analgesia and side effects, primarily postoperative nausea and vomiting (PONV).

Methods: Forty‐two children were randomised into one of three groups: sevoflurane anaesthesia and epidural solution with fentanyl (SBAF); sevoflurane anaesthesia and epidural solution without fentanyl (SBA); propofol anaesthesia and epidural solution without fentanyl (PBA).

Results: Including fentanyl in the epidural mixture resulted in excellent postoperative analgesia without any need of i.v. opioids. However, 7 out of 16 children were nauseated and needed antiemetic drugs. On average, a 55–75% higher dose of bupivacaine was necessary to assure adequate analgesia when an epidural mixture without fentanyl was used. In addition, significantly more children needed i.v. opioids. Under these conditions there was no significant difference in pain scoring between the groups. There was significantly less nausea and less use of antiemetic drugs in children having epidurals without fentanyl in the sevoflurane groups. The same tendency, although not significant, was observed in the whole material. Sevoflurane anaesthesia resulted in less PONV than propofol anaesthesia, probably due to the higher amount of intravenous fentanyl used with the latter. This difference was not significant due to the small number of children included. Incidence of pruritus related significantly to epidural fentanyl.

Conclusion: A satisfactory postoperative analgesia can be achieved with both epidural mixtures used in the study. Epidural fentanyl results in better analgesia, but significantly more PONV and greater use of antiemetic drugs. Omitting epidural fentanyl results in less PONV, but significantly less profound analgesia and a need for additional treatment with i.v. opioids, in addition to a 55–75% higher epidural bupivacaine infusion. Both epidural treatments result in high and similar patient satisfaction and no serious complications. The study could not show any significant difference between the effect of sevoflurane and propofol anaesthesia on PONV.
Neostigmine 50 μg kg−1 with glycopyrrolate increases postoperative nausea in women after laparoscopic gynaecological surgery
Authors: Løvstad R. Z. , Thagaard K. S. , Berner N. S. , Raeder J. C.
Published: March 2003

Background: Neostigmine, used for reversal of neuromuscular block, has been implicated in the development of postoperative nausea and vomiting (PONV). The use of mivacurium, which does not require neostigmine reversal due to its metabolism by plasma cholinesterase, has made it possible to study the effect of neostigmine on PONV in a randomised, double‐blind, placebo‐controlled manner.

Methods: Ninety healthy women scheduled for laparoscopic gynaecological surgery were randomly allocated to two groups in a double‐blind manner. One group was given neostigmine (50 μg kg−1) and glycopyrrolate (10 μg kg−1) (group NG), the other NaCl i.v. as placebo (group P) at the end of surgery when all the patients were spontaneously reversed to at least 75% of full muscle power. The risk of PONV was reduced by using low doses of opioids and ondansetron prophylaxis. All the patients were monitored and assessed for 24 h with regard to pain, nausea, vomiting and overall satisfaction.

Results: There was a statistically significant difference (P=0.03) in the occurrence of nausea during the first 6 h postoperatively between NG group (30%) and P group (11%), resulting in the more extensive use of antiemetic drugs in the NG group (28%) than in P group (7%) (P=0.01) in this period. There was no difference between the groups in the frequency of vomiting; seven nauseated patients had vomiting, four in group NG, three in group P. Total number of patients with PONV during the observation period of 24 h, usage of antiemetic rescue medication and overall patient satisfaction did not differ significantly between the groups.

Conclusion: The results suggest that antagonism of neuromuscular block with a high dose of neostigmine increases postoperative nausea and the use of antiemetic drugs during the first 6 h after administration.
One way to ventilate patients during fibreoptic intubation
Authors: Slots P. , Reinstrup P.
Published: March 2003

Occasionally anaesthesiologists find themselves in situations where ventilation during intubation with a fibreoptic bronchoscope (FOB) is desirable. In order to ventilate the patient during the FOB intubation, we used a 90° angle swivel connector, normally used for fibreoptic bronchoscopia in an intubated patient. After a nasotracheal tube is placed with the tip in the oropharynx, ventilation of the patient is possible via this tube by closing the mouth and other nostril. The fibrescopic procedure is done through the right‐angle connector with suction port and the tube is used to guide the tip of the FOB to the aditus laryngis. The method has been used in 7 patients who were impossible to intubate with a conventional procedure. In all patients ventilation was possible and intubation was performed in 5 min (range 1–15).
Orthotopic liver transplantation in a patient with severe portopulmonary hypertension
Authors: Mair P. , Kaehler C. H. , Pomaroli A. , Schwarz B. , Vogel W. , Margreiter R.
Published: March 2003

Liver transplantation in patients with severe portopulmonary hypertension (PPH) has been associated with mortality rates in the range of 70% to 80%. Preoperative long‐term epoprostenol therapy reverses pulmonary hypertension and may be a valuable possibility to reduce mortality in patients with severe PPH undergoing orthotopic liver transplantation. We want to report a patient with severe PPH, who was treated with intravenous epoprostenol for an 8‐month period, after which pulmonary vascular resistance had decreased from 12 to 3 Wood units. Nevertheless, the patient developed intractable perioperative right heart failure necessitating transient mechanical circulatory support. The patient was weaned from mechanical circulatory support, but died from another episode of acute right heart failure after 28 days. Complicated liver transplantation associated with major cardiovascular stress is obviously not tolerated in patients with severe portopulmonary hypertension even after preoperative long‐term epoprostenol therapy.
Haemodynamic changes and vasopressin release are not consistently associated with carbon dioxide pneumoperitoneum in humans
Authors: Lentschener C. , Axler O. , Fernandez H. , Megarbane B. , Billard V. , Fouqueray B. , Landault C. , Benhamou D.
Published: March 2003

Background: Conflicting haemodynamic changes, suggested to be caused by vasopressin release, have been reported during carbon dioxide (CO2) pneumoperitoneum. However, peritoneal stimulations including open surgery cause both a systemic vasopressor response and a vasopressin release, which are suppressed by opiate administration. Also, a decreased venous return of blood to the heart causes vasopressin release. Furthermore, previous haemodynamic assessments of laparoscopic surgery have been conducted using various anaesthetic regimens, which are likely to have caused various haemodynamic effects. We hypothesised that intraoperative haemodynamic and/or humoral changes would not be observed in association with laparoscopic surgery provided that, (a) normovolaemia is continuously maintained using transoesophageal echocardiographic (TEE) assessment, and (b) adequate depth of general anaesthesia is continuously maintained by bispectral index (BIS) monitoring and high plasma Ievel opiate administration.

Methods: Twenty ASA 1 women undergoing laparoscopic surgery received 10 ml  ·  kg−1 lactated Ringer’s solution and thereafter were randomly allocated to receive intraoperatively either 8 ng  ·  ml−1 or 4 ng  ·  ml−1 plasma remifentanil concentrations while BIS was maintained at 50±5 by isoflurane alteration. The group receiving 4 ng  ·  ml−1 remifentanil was used as control. Expired CO2 was maintained within a 32–38 kPa range throughout the investigation. Complete TEE haemodynamic investigation was performed before pneumoperitoneum (PP) (T1), and during PP horizontal (T2), with a head‐up tilt (T3), with a head‐down tilt (T4), horizontal (T5), and PP released (T6). Plasma vasopressin, epinephrine and norepinephrine levels were measured at T1, T3, and T6. ANOVA, Student’s t‐test and Mann‐Whitney U‐test were used for statistical analysis.

Results: Haemodynamic indices and humoral values did not change significantly within and between remifentanil groups throughout the investigation (all P<0.05).

Conclusion: Continuous adequate depth of anaesthesia and normovolaemia may have prevented both a humoral and a haemodynamic response, initiated in the peritoneum by the contact with CO2 in previous investigations.
Risk factors associated with new onset tachyarrhythmias after cardiac surgery – a retrospective analysis
Authors: Mayr A. , Knotzer H. , Pajk W. , Luckner G. , Ritsch N. , Dünser M. , Ulmer H. , Schobersberger W. , Hasibeder W.
Published: March 2003

Background: Tachyarrhythmias (TA) represent a frequent and serious problem after cardiac surgery. We retrospectively analyzed 987 cardiac surgery patients admitted to a surgical intensive care unit between 1996 and 1999 to assess incidence and risk factors associated with development of postoperative TA in the intensive care unit.

Methods: TA (n=149) were defined as non‐sinus rhythm with a heart rate (HR) ≥100 bpm in patients with preoperative sinus rhythm or as heart rate ≥130 bpm in patients with preoperative atrial fibrillation. A total of 787 patients served as controls (C). Demographic, premorbidity and perioperative data, admission SAPS and MODS‐score, presence of clinical syndromes systemic inflammatory response syndrome (SIRS) and sepsis were univariately compared between groups. For prediction of independent risk factors for TA‐development two multiple logistic regression models were finally established.

Results: Concerning TA, atrial fibrillation and flutter (76%) were observed most frequently, followed by paroxysmal supraventricular tachycardia (15%) and ventricular tachycardia/fibrillation (11%). Age, a history or presence of congestive heart failure, development of SIRS and sepsis, severity of multiple organ dysfunction syndrome and in particular severity of cardiovascular failure proved to be independent risk factors for development of TA.

Conclusion: In cardiac surgery patients, age, a history or presence of congestive heart failure, postoperative development of a systemic inflammatory response syndrome or sepsis and the severity of multiple organ function syndrome were independent predictors for development of TA in the intensive care unit. The association of severity of cardiovascular dysfunction with TA strongly suggests a causal relationship between catecholamine therapy and TA‐development.
Evaluation of two methods to calculate p50 from a single blood sample
Authors: Ekeloef N. P. , Eriksen J. , Kancir C. B.
Published: March 2003

Background: The hemoglobin‐oxygen affinity is conveniently described as the oxygen tension at which the hemoglobin is 50% saturated (p50). We compared two methods of single‐point analysis for p50 calculation, using clinical data.

Methods: From patients submitted to anesthesia for major surgery, 114 arterial or venous blood samples were analyzed by using the Sigaard‐Andersen oxygen status algorithm (p50OSA) and Doyle’s method (p50Doyle) based on Hill’s equation.

Results: The oxygen saturation and tension varied respectively between 0.64–0.96 and 3.8 kPa–11.0 kPa. A Bland‐Altman analysis showed a mean difference of 0.04 kPa (SD 0.12 kPa). The limits of agreement were −0.20 kPa and +0.28 kPa.

Conclusions: The Siggaard‐Andersen oxygen status algorithm is presently the most clinically useful single‐point method of p50 calculation.
Inhibitory effects of S‐(−) and R‐(+) bupivacaine on neutrophil function
Authors: Welters I. D. , Menzebach A. , Langefeld T. W. , Menzebach M. , Hempelmann G.
Published: March 2003

Background: Local anesthetics inhibit migration, enzyme release and superoxide anion generation of polymorphonuclear leukocytes (PMN). Due to their ability to phagocytose and kill bacteria PMN represent a major defense mechanism in the circulating blood. In this study we determined the influence of racemic bupivacaine and its enantiomers on neutrophil phagocytic activity, oxidative burst as well as surface expression of complement and Fcγ receptors.

Methods: Venous blood was pre‐incubated with different concentrations of either racemic bupivacaine, R‐(+) or S‐(−) bupivacaine. Fluoresceine isothiocyanate (FITC)‐labeled antibodies against Fcγ receptor III (CD16), complement receptor 1 (CD35) and complement receptor 3 (CD11b) were used to determine surface receptor expression. Phagocytic activity was measured by ingestion of FITC‐labeled vital Staphylococcus aureus. Oxidative burst was determined by conversion of nonfluorescent dihydrorhodamine 123 into fluorescent rhodamine 123. Fluorescent intensity of each sample was determined by flow cytometry.

Results: Racemic bupivacaine inhibited surface receptor expression, phagocytosis, and oxidative burst in a time‐ and concentration‐dependent manner. Although the S‐(−) enantiomer exerted significantly less inhibitory action on neutrophil function compared to R‐(+) and racemic bupivacaine, these effects were small compared to the overall changes.

Conclusion: These findings suggest that bupivacaine impairs surface receptor expression and may thereby contribute to reduced phagocytic activity and oxidative burst. Enantiomer‐specific effects of bupivacaine may play a minor role in the inhibition of these leukocyte functions.
A bilateral clinical model for the study of acute and chronic pain after breast‐reduction surgery
Authors: Bell R. F. , Sivertsen Å. , Mowinkel P. , Vindenes H.
Published: March 2003

Background: There is a need for new clinical models to investigate effectively the development of pain after surgery and the effect, if any, of pre‐emptive treatment. Bilateral models are of special interest, since the patient serves as his/her own control. The objective of this preliminary study was to test a clinical model for the study of acute and chronic pain after bilateral reduction mammoplasty.

Methods: Eight patients participated in the study where the breasts were randomized to test and control groups. In each patient, one breast was preoperatively infiltrated with lidocaine and adrenaline and the other breast infiltrated with saline and adrenaline. Assessment included visual analogue scale (VAS) pain intensity, thermal thresholds, mapping for punctate hyperalgesia and tactile sensation. Assessments were made preoperatively, postoperatively and at 6 months after surgery.

Results: With regard to acute postoperative pain intensity, the model demonstrated a clear difference between lidocaine and placebo treated breasts. There was no difference between lidocaine and placebo treated breasts with regard to chronic pain, but these results are inconclusive due to small number of patients.

Conclusion: The model is sensitive and may be useful in studies of mechanisms of development and prevention of chronic pain after surgery.
Inclusion of lignocaine base into a polar lipid formulation –in vitro release, duration of peripheral nerve block and arterial blood concentrations in the rat
Authors: Dyhre H. , Wallin R. , Björkman S. , Engström S. , Renck H.
Published: March 2003

Background: Slow‐release formulations of local anaesthetics may produce nerve blocks of long duration. The present study aimed at investigating the in vitro and in vivo properties of a polar lipid formulation for slow release of lignocaine and the effects on nerve block duration by inclusion of dexamethasone into the system.

Methods: In vitro release of lignocaine from the lipid formulation was studied in a US Pharmacopoeia rotating apparatus. Sciatic nerve blocks were induced in rats by 0.1 ml of test formulations containing lignocaine HCl 20 mg  ·  ml−1 in aqueous solution, lignocaine base 20, 100 or 200 mg  ·  ml−1 in lipid formulation or the last formulation with dexamethasone 0.05, 0.5 or 5 mg  ·  ml−1. The durations of sensory and motor block and the arterial blood concentrations of lignocaine were investigated.

Results: In vitro there was a sustained release of lignocaine from the lipid formulation, with 50% release at around 48 h. In vivo lignocaine base 20 mg  ·  ml−1 in lipid formulation produced sciatic nerve blocks of significantly shorter duration than lignocaine HCl 20 mg  ·  ml−1 in aqueous solution, while lignocaine base 100 and 200 mg  ·  ml−1 in lipid formulation produced blocks lasting two and three times longer, respectively, than the lignocaine HCl solution. Addition of dexamethasone did not affect the duration of nerve block. Following administration of lignocaine base 200 mg  ·  ml−1 in lipid formulation, as compared to lignocaine HCl 20 mg  ·  ml−1 in aqueous solution, the maximal blood concentration of lignocaine was only three times higher in spite of the ten‐fold difference in dose, and the mean terminal half‐life was three times longer, reflecting the slow release from the formulation.

Conclusions: Our findings indicate that lignocaine base in polar lipids acts as a slow‐release preparation of local anaesthetic both in vitro and in vivo.
Fentanyl does not improve the nerve block characteristics of axillary brachial plexus anaesthesia performed with ropivacaine
Authors: Fanelli G. , Casati A. , Magistris L. , Berti M. , Albertin A. , Scarioni M. , Torri G.
Published: March 2003

Background: The aim of this prospective, randomized, double‐blind study was to evaluate the effects of adding 1 μg · kg−1 fentanyl to ropivacaine 7.5 mg · ml−1 for axillary brachial plexus anaesthesia.

Methods: With Ethics Committee approval and written consent, 30 ASA physical status I–II in‐patients, scheduled for orthopaedic hand procedures were randomly allocated to receive axillary brachial plexus block with 20 ml of either ropivacaine 7.5 mg · ml−1 (n=15) or ropivacaine 7.5 mg · ml−1+1 μg · ml−1 fentanyl (n=15). Nerve blocks were placed using a nerve stimulator with the multiple injection technique. A blinded observer recorded the time to onset of surgical block (loss of pinprick sensation in the innervation areas of the hand (C6–C8) with concomitant inability to flex the wrist against gravity and move the fingers when squeezing the hand) and first request for pain medication after surgery.

Results: No differences in demography, degree of sedation or peripheral oxygen saturation were observed between the two groups. Median (range) time required to achieve readiness for surgery was 15 min (5–36 min) with ropivacaine alone and 15 min (5–40 min) with the ropivacaine‐fentanyl mixture. No differences in the intraoperative quality of nerve block were reported between the two groups. Four patients receiving ropivacaine plain and two patients receiving the ropivacaine‐fentanyl mixture did not require analgesics during the first 24 h after surgery (P=0.62). The degree of pain experienced at first analgesic request in those patients asking for pain medication, as well as median consumption of postoperative analgesics, were similar in the two groups. First postoperative analgesic request was made at 11 h (25th–75th percentiles: 9.1–14 h) in patients receiving ropivacaine alone and at 11.8 h (25th–75th percentiles: 9.8–15 h) in patients receiving the ropivacaine‐fentanyl mixture (P=0.99).

Conclusion: The addition of fentanyl 1 μg · ml−1 to ropivacaine 7.5 mg · ml−1 does not improve the nerve block characteristics of axillary brachial plexus anaesthesia for orthopaedic procedures involving the hand.
Onset and duration of action of rocuronium – from tracheal intubation, through intense block to complete recovery
Authors: Schultz P. , Ibsen M. , Østergaard D. , Skovgaard L. T.
Published: March 2003

Background: The primary objective of this study was to establish the relation between the post tetanic count (PTC) and the time to reappearance of the first response (T1) in train‐of‐four (TOF) nerve stimulation following rocuronium 0.6 mg/kg, 0.9 mg/kg, and 1.2 mg/kg. The secondary objective was to evaluate the intubation conditions after 1 min.

Methods: One hundred and eight patients were randomised to one of three doses of rocuronium: 0.6, 0.9 or 1.2 mg/kg. Tracheal intubation was performed at 60 s by a blinded investigator. During propofol, fentanyl, midazolam anaesthesia the neuromuscular block was monitored by mechanography using TOF stimulation every 12 s. At 6 min intervals, a tetanic stimulation (50 Hz) was applied for 5 s preceded and followed by a 30 s period of 1 Hz stimulation until the reappearance of T1.

Results: There was a significant difference in recovery following the high dose and the two lower doses. The relation between time (min) to reappearance of T1 (t) and PTC can be expressed as follows: and . T1 was seen at a mean PTC level of 8 or 9 in all three groups. The intubation conditions were graded as excellent or good in all patients except in two patients following the 0.6 mg/kg dose of rocuronium.

Conclusion: The PTC method can be used to predict the time to first response to TOF nerve stimulation during intense rocuronium induced neuromuscular blockade. The relation between PTC and the time to T1 was prolonged after 1.2 mg/kg compared with 0.6 mg/kg and 0.9 mg/kg. No further improvement in intubation conditions at 60 s was evident by increasing the rocuronium dose from 0.9 mg/kg to 1.2 mg/kg.
Does discontinuation of desflurane at the time of neostigmine administration speed recovery from cisatracurium block compared to that with a propofol‐based technique?
Authors: Kirkegaard‐Nielsen H. , Caldwell J. E. , Abengochea A. , Berry P. D. , Heier T.
Published: March 2003

Background: Volatile anaesthetics are known to influence the effect of neostigmine as an antagonist of neuromuscular block. The aim of the present study was to investigate whether discontinuation of desflurane at the time of neostigmine administration shortens reversal time from cisatracurium block, compared to that with a propofol‐based anaesthesia.

Methods: Ten volunteers were studied twice. For one study, anaesthesia was induced with alfentanil and propofol and maintained with nitrous oxide 70% and propofol 150 μg · kg−1 · min−1. For the other study, experimental conditions were replicated except that desflurane 6% was administered and the dose of propofol was only 50 μg · kg−1 · min−1. The evoked mechanical response of the adductor pollicis to train‐of‐four (TOF) stimulation was recorded. Neuromuscular block was induced with cisatracurium 0.2 mg · kg−1. When the magnitude of the first TOF response (T1) had recovered to 10%, the block was antagonized with neostigmine 70 μg · kg−1. At this time, propofol was decreased to 50 μg · kg−1 · min−1, or the desflurane was discontinued.

Results: There were no significant differences between the two techniques of anaesthesia in the rate of neostigmine‐induced recovery of the TOF ratio. The times (mean±SD) to achieve TOF ratios of 0.7, 0.8, and 0.9 were (propofol first, desflurane second) 6.1±2.2 and 6.5±1.6 min; 10.4±4.2 and 9.6±2.7 min; 17.1±6.9 and 21.0±13.0 min, respectively.

Conclusion: Discontinuing desflurane does not speed neostigmine‐induced recovery from cisatracurium neuromuscular block, when compared to that during propofol‐based anaesthesia.
Similar haemodynamic, respiratory and metabolic changes with the use of sevoflurane or halothane in children breathing spontaneously via a laryngeal mask airway
Authors: Erb T. , Christen P. , Kern C. , Frei F. J.
Published: March 2003

Background: In preschool children, short‐lasting surgical procedures are often performed under combined inhalational and regional anaesthesia with the child breathing spontaneously via a laryngeal mask airway (LMA). Despite widespread use, only limited data are available on haemodynamic, respiratory and metabolic effects of sevoflurane and halothane during LMA anaesthesia.

Methods: In an open‐label, randomised, controlled study, 49 children (aged 3–8 years) were allocated to receive either sevoflurane or halothane in 60% nitrous oxide. After insertion of the LMA, end‐tidal concentrations of sevoflurane or halothane were maintained at 1 MAC with the child ventilating spontaneously throughout the entire procedure. Analgesia was provided by caudal block. Haemodynamic and respiratory parameters were recorded, and capillary blood‐gas samples were obtained repeatedly.

Results: Changes in heart rate (HR) and systolic blood pressure were similar in both groups during all observed periods, apart from a significantly higher increase in HR during inhalational induction with sevoflurane (P<0.05). Regression slope analysis during anaesthesia revealed a decrease of the respiratory rate of 5 breaths h−1 (P<0.001) and an increase of end‐tidal PCO2 and capillary PCO2 of about 0.25 kPa h−1 (P<0.001), with no significant difference between the two groups. Base excess, calculated in capillary blood gas samples, did not change over time (P>0.5) in either group.

Conclusions: The use of approximately 1 MAC sevoflurane or halothane in 60% N2O in children breathing spontaneously via LMA resulted in comparable haemodynamic, respiratory and metabolic changes, and clinically relevant deteriorations did not occur during the 65‐min study period.
The systemic inflammatory response after cardiac surgery with cardiopulmonary bypass in children
Authors: Brix‐Christensen V.
Published: March 2003

Paediatric cardiac surgery often requires cardiopulmonary bypass (CPB) during the surgical intervention. CPB is known to elicit a systemic inflammatory response with activation of the complement and coagulation systems, stimulation of cytokine production, cellular entrapment in organs, neutrophil activation with degranulation, platelet activation, and endothelial dysfunction. These changes are associated with a risk of postoperative organ dysfunction and increased morbidity and mortality in the postoperative period. Clinical studies have concentrated on measurement of inflammatory markers and mediators in peripheral blood, where the systemic inflammatory response in the paediatric cardiac patient seems to be different from the adult case. Looking at the organ level, experimental studies have the advantage of providing information contributing to a better understanding of the pathological events that may lead to the deteriorated organ function. This review focuses on the systemic inflammatory response after cardiac surgery with CPB in children and experimental CPB models.
Lack of agreement between thermodilution and carbon dioxide‐rebreathing cardiac output
Authors: Nilsson L. B. , Eldrup N. , Berthelsen P. G.
Published: March 2003

Background: A continuous, accurate, non‐invasive monitor of cardiac output would represent a major step forward in patient management. A cardiac output computer, NICO2, based on the Fick principle and an automatic partial carbon dioxide (CO2)‐rebreathing technique has just become available. We compared the performance of this monitor with the standard thermodilution method.

Methods: Thirty patients were investigated after cardiac surgery. Replicate measurements were performed simultaneously with the thermodilution and NICO2 techniques. An Altman‐Bland analysis was used to assess repeatability of each of the two methods and to determine the agreement between the two techniques.

Results: The repeatabilities of thermodilution and CO2‐rebreathing cardiac output were excellent, with coefficients of repeatability of 0.35 l/min and 0.60 l/min. Mean thermodilution and NICO2 cardiac output were 4.4 l/min (SD 0.9, range 2.7–6.1) and 4.6 l/min (SD 1.3, range 1.6–6.9). A comparison of the methods, however, revealed excessive limits of agreement (±1.80 l/min).

Conclusion: The agreement between the NICO2 derived cardiac output and the de facto standard – thermodilution cardiac output – is poor. The methods are not interchangeable with the present version of the NICO2. The repeatability of the partial CO2‐rebreathing technique holds promise that a sufficient accuracy may be obtained by suitable modifications of the monitor’s algorithms.
High incidence of pruritus after large doses of hydroxyethyl starch (HES) infusions
Authors: Kimme P. , Jannsen B. , Ledin T. , Gupta A. , Vegfors M.
Published: March 2003

Background: There are several studies indicating a correlation between treatment with hydroxyethyl starch (HES) and pruritus. In order to see whether there is a possible dose–response relationship between HES and pruritus, we retrospectively studied 50 patients who had received HES in varying doses (cumulative dose 500–19500 ml) as hemodilution therapy after subarachnoid hemorrhage.

Methods: Of 50 consecutive patients, 6 were excluded due to severe neurological sequelae. A questionnaire was sent to the remaining 44 patients at 6 months (5–12 months) median (range) after the end of HES treatment.

Results: We received answers from 37 patients, of whom 54% reported pruritus. On average pruritus lasted for 15 weeks. There was significantly more pruritus in patients who received more than 5000 ml of HES versus those who received less than 5000 ml (P=0.023). Pruritus had a delayed onset and appeared as pruritic crises lasting for 2–30 min. It had a patchy distribution in most patients and no predilected locations. In 4 patients (20%) the pruritus lasted longer than 21 weeks.

Conclusion: Our study indicates that there is a dose‐dependency for the incidence of HES‐induced pruritus, and that in some cases the pruritus may be severe and long‐lasting.
Dynamic changes in cerebral oxygenation related to deep hypothermia and circulatory arrest evaluated by near‐infrared spectroscopy
Authors: Abdul‐Khaliq H. , Schubert S. , Troitzsch D. , Huebler M. , Boettcher W. , Baur M. O. , Lange P. E.
Published: March 2003

Background: Total circulatory arrest in deep hypothermia, which is used in corrective surgery of complex cardiovascular malformations, has been said to cause brain injury. Near‐infrared spectroscopy (NIRS) is a new non‐invasive method that potentially monitors changes in cerebral oxygenation and tissue oxygen utilisation. The aim of this experimental study in rabbits was to evaluate the change in intravascular and intracellular oxygenation patterns during cooling, deep hypothermic circulatory arrest and rewarming using a commercially available NIRS‐cerebral oximeter.

Methods: Ten New Zealand White male rabbits (weight, 3.1±0.25 kg BW) were included in this study. All animals underwent cardiopulmonary bypass (CPB), cooling to a rectal temperature below 15 °C, 60 min of deep hypothermic circulatory arrest (DHCA) followed by reperfusion and rewarming. Cerebral oxyhaemoglobin (HbO2), deoxyhaemoglobin (HHb) and cytochrome oxidase aa3 (CytOxaa3) concentrations were continuously measured during the entire procedure using the Cerebral RedOxTM Monitor 2020 (Criticon cerebral redox monitor 2020, Johnson & Johnson Medical). Total haemoglobin concentration (tHb) and regional cerebral oxygen saturation (rSO2) values were calculated by integrated algorithm.

Results: In all animals an initial increase of oxygenated haemoglobin (HbO2, rSO2) and a fall in deoxygenated haemoglobin (HHb) were found during cooling on bypass. A slight decrease in CytOxaa3 signal was observed in response to initial cooling. Variation in intravascular haemoglobin oxygenation parameters (HbO2, HHb) were related to haemodynamic changes associated with fluid loading, initiation and termination of CPB, bypass flow rate and cooling and rewarming. When the pump flow was stopped all NIRS parameters, except the HHb value, decreased precipitously during the DHCA‐period (P<0.01). After reperfusion and rewarming, all haemoglobin oxygen saturation readings returned nearly to pre‐CPB levels (P=0.09), but the CytOxaa3 was still significantly lower than the pre‐CPB levels (P<0.05).

Conclusion: The change in the NIRS‐derived haemoglobin oxygenation parameters may reflect physiological changes in systemic and cerebral haemodynamics. CytOxaa3 values may represent related effects on cellular oxygenation. Thus, continuous, real‐time NIRS‐monitoring may identify critical periods with inadequate brain tissue oxygenation, particularly during DHCA. The neurological implications of the observed changes in NIRS oxygenation parameters, however, require further quantitative morphological evaluation of the brain in animals surviving a longer reperfusion and observation period.
Risk factors for nosocomial intensive care infection: a long‐term prospective analysis
Authors: Appelgren P. , Hellström I. , Weitzberg E. , Söderlund V. , Bindslev L. , Ransjö U.
Published: March 2003

Background: To identify risk factors for nosocomial infection in intensive care and to provide a basis for allocation of resources.

Methods: Long‐term prospective incidence study of risk factors for nosocomial infection in the surgical‐medical intensive care unit of a university hospital.

Results: A total of 2671 patients were admitted during four years, and 562 of 574 patients staying >48 h were observed during 4921 patient days (median length of stay 5 days, range 2–114). Of these, 196 (34%) patients had 364 nosocomial infections after median 8–10 days, an infection rate of 14/100 admissions. Infection prolonged length of stay 8–9 days and doubled the risk of death. The infections were 17% blood stream, 26% pneumonias, 34% wound, 10% urinary tract and 13% other infections. The incidence of bloodstream infection declined significantly during the study years, from 12% to 5%. In multiple regression analysis, the important variables for infection were central venous catheter, mechanical ventilation, pleural drainage and trauma with open fractures. High age, immunosuppression and infection on admission did not influence the risk of acquiring infection. Trauma patients constituted 24% of the study population. Trauma with open fractures increased the risk of infection more than twice (P=0.003), mainly due to wound infections.

Conclusion: Trauma cases, with open fractures, were the patients most at risk of infection, despite low disease severity scores. Resources to prevent nosocomial infection should be allocated to these patients.
Studies on fluid extravasation related to induced hypothermia during cardiopulmonary bypass in piglets
Authors: Heltne J. K. , Koller M. E. , Lund T. , Farstad M. , Rynning S. E. , Bert J. L. , Husby P.
Published: March 2003

Background: Hypothermia, commonly used for organ protection during cardiopulmonary bypass (CPB), has been associated with changes in plasma volume, hemoconcentration and microvascular fluid shifts. Fluid pathophysiology secondary to hypothermia and the mechanisms behind these changes are still largely unknown. In a recent study we found increased fluid needs during hypothermic compared to normothermic CPB. The aim of the present study was to characterize the distribution of the fluid given to maintain normovolemia. In addition, we wanted to investigate the quantity and quality of the fluid extravasated during hypothermic compared to normothermic CPB.

Methods: Two groups of anesthetized piglets were studied during 2 h of hypothermic (28 °C) (n=7) or normothermic (38 °C) (n=7) CPB. Net fluid balance (input−output) was recorded. Changes in colloid osmotic pressures of plasma (COPp) and interstitial fluid (COPi), plasma volume (PV), hemoglobin (Hb), hematocrit (HCT), mean corpuscular volume (MCV), s‐osmolality, s‐albumin and s‐total protein was followed throughout the experiments. Fluid extravasation rate was calculated. In addition, total tissue water content was measured and compared with a control group (n=6) (no CPB).

Results: During hypothermic compared with normothermic CPB, the average net positive fluid balance from 10–120 min of extracorporeal circulation was 1.35±0.06 ml · kg−1 · min−1 and 0.33±0.03 ml · kg−1 · min−1 respectively (P<0.0001). We found a marked increase in fluid extravasation during hypothermic CPB. The extravasation rate during hypothermia was 1.8±0.2 ml · kg−1 · min−1, (1st hour) and 1.1±0.2 ml · kg−1 · min−1 (2nd hour) compared with 0.8±0.2 ml · kg−1 · min−1, and 0.1±(0.1) ml · kg−1 · min−1 during normothermia, respectively (P<0.01). The total intravascular protein and albumin masses remained constant in both groups. Following hypothermic CPB, the water content increased significantly in all tissues and organs.

Conclusion: During hypothermic CPB an increased extravasation of fluid from the intravascular to the interstitial space was found. As no leakage of proteins could be demonstrated, based on stable values for albumin and protein masses throughout the experiments, the extravasated fluid contained mainly water and small solutes.
Frequency of haemoglobin desaturation with the use of succinylcholine during rapid sequence induction of anaesthesia
Authors: Hayes A. H. , Breslin D. S. , Mirakhur R. K. , Reid J. E. , O'Hare R. A.
Published: March 2003

Background: The perceived safety of the use of succinylcholine is based on the fact that recovery from its effects will occur before oxygen desaturation occurs in case of failure to intubate or ventilate. The purpose of this study was to examine the incidence of oxygen desaturation after the use of succinylcholine prior to resumption of spontaneous ventilation following four different preoxygenation techniques.

Methods: Twenty‐five patients each were randomly allocated to preoxygenation with 4 deep breaths of 100% oxygen or by breathing oxygen for 1, 3 or 5 min following which they received a rapid sequence induction of anaesthesia with fentanyl 1 μg kg−1, a sleep dose of thiopentone and succinylcholine 1 mg kg−1. Oxygen saturation was monitored continuously using a finger probe. Ventilation was not assisted unless the saturation decreased to ≤90%.

Results: Eleven out of the 100 patients had a decrease in their oxygen saturation to ≤90% before the resumption of effective spontaneous ventilation irrespective of the technique of preoxygenation.

Conclusion: We conclude that use of succinylcholine may not always prevent desaturation if there is a failure to intubate and ventilate during a rapid sequence induction of anaesthesia.
Combination of droperidol and ondansetron reduces PONV after pediatric strabismus surgery more than single drug therapy
Authors: Shende D. , Bharti N. , Kathirvel S. , Madan R.
Published: March 2003

Background: Pediatric strabismus surgery is associated with a very high incidence of postoperative nausea and vomiting [(PONV) 44–88%]. Droperidol (10–75 μg kg−1) and ondansetron (50–150 μg kg−1) have shown variable success in reducing the incidence and severity of PONV. Combination of these two drugs has shown promising results. This randomized, double‐blind, placebo‐controlled clinical trial was conducted to evaluate the efficacy and safety of the combination of these two drugs in reducing the incidence and severity of PONV in pediatric strabismus surgery.

Methods: After institutional approval and parental informed consent, 240 children of ASA physical status I and II of either sex, aged 1–15 years were included in this study. None of the children received any premedication and a standardized anesthesia technique was used for all the children. They were prospectively randomized to one of the four treatment groups. Group PP received normal saline placebo intravenously after induction and at the end of the procedure. Group DP received droperidol 25 μg kg−1 after induction and normal saline at the end. Group OP received ondansetron 150 μg kg−1 after induction and saline at the end. Group DO received droperidol 15 μg kg−1 after induction and ondansetron 100 μg kg−1 at the end.

Results: Combination prophylaxis resulted in a lower incidence of PONV (13%) as compared to placebo (62.5%, P<0.001), ondansetron (37%, P<0.001), or droperidol (32%, P<0.01).

Conclusion: Droperidol 15 μg kg−1 in combination with ondansetron 100 μg kg−1, administered at the induction and end of the operative procedure respectively, is more effective than either drug given individually in reducing the incidence of PONV after strabismus surgery.
Effects of changes in frequency and inspiratory time on arterial oxygenation and CO2 elimination during high‐frequency jet ventilation in a child with laryngotracheal papillomata
Authors: Akata T. , Noda Y. , Takahashi S.
Published: March 2003

An 11‐yr‐old female without any pulmonary disorders underwent laser resections of laryngotracheal tumors using high‐frequency jet ventilation (HFJV) 6 times over a period of 17 months at our institute. In this series of surgeries, we studied the effects on PaO2 and PaCO2 during HFJV of changes of either frequency or inspiratory time. Increasing the frequency from 100 to 400/min decreased the PaO2 and increased the PaCO2. Decreasing the inspiratory time from 30% to 20% increased the PaCO2, although it did not affect the PaO2. All the procedures were uneventfully carried out without critically impairing gas exchange during HFJV. In this patient with normal lung function, CO2 elimination during HFJV appeared to be facilitated by either decreasing the frequency or increasing the inspiratory time. Arterial oxygen tension during HFJV was higher at lower frequencies.
Pain on injection of propofol with or without infusion of carrier fluid
Authors: Liljeroth E. , Grauers A. , Åkeson J.
Published: March 2003

Background: Propofol, a popular intravenous (iv) anaesthetic induction agent for brief cases or day surgery, is associated with smooth induction, pleasant sleep, rapid recovery and little postoperative nausea. A major disadvantage is pain at the site of injection. The aim of the present study was to examine the influence of simultaneous iv infusion of carrier fluid on propofol‐induced local pain.

Methods: Thirty patients, scheduled for ear‐nose‐throat or plastic surgery under general anaesthesia, were randomly allocated into two groups. Each patient had two 2 ml iv bolus injections of propofol given at two minutes’ interval. In group I (n=15) the first bolus injection was given with no iv carrier fluid and the second one given with a 10 ml iv carrier fluid infused over 10 s. Correspondingly, the patients in group II (n=15) had their first injection with and their second one without the iv carrier fluid. Following each injection of propofol the patients were asked by a blinded investigator to score their pain on a 10‐point visual analogue scale, and to report the appearance, maximum and disappearance of pain. After the second assessment of pain, general anaesthesia was induced with more propofol.

Results: Pain intensity at the site of propofol injection was found not to be influenced by simultaneous iv infusion of carrier fluid.

Conclusion: It seems, from the results obtained here, that simultaneous iv infusion of carrier fluid has no particular effect on local pain following iv administration of propofol.
Changes in cardiac output and intrathoracic blood volume: a mathematical coupling of data?
Authors: Buhre W. , Kazmaier S. , Sonntag H. , Weyland A.
Published: March 2003

Background: Measurements of intrathoracic blood volume (ITBV) provide volumetric information about cardiac preload and are used to investigate the cause of alterations in cardiac output (CO). On the other hand, CO is required to calculate ITBV. Thus, concerns have been raised with respect to a mathematical coupling of data. The aim of this prospective, clinical study was to investigate whether a variation in CO induced by high‐dose beta‐blockade influences thermodilution measurements of ITBV in the absence of changes in intravascular volume in patients undergoing minimally invasive coronary artery bypass grafting.

Methods: Sixteen patients undergoing elective minimally invasive direct coronay artery bypass (MIDCAB) surgery were studied. Transpulmonary thermodilution measurements of ITBV and CO were simultaneously performed before bypass grafting, during beta‐blockade induced by high‐dose esmolol and at the end of surgery.

Results: During esmolol administration, CO significantly decreased by 33%, whereas ITBV remained unchanged compared to control values (876±46 ml m−2 during control versus 860±61 ml m−2 during esmolol administration). After the end of esmolol administration, CO significantly increased by 79%. Again, ITBV remained virtually unchanged (860±61 ml m−2 during esmolol administration versus 911±38 ml m−2 after esmolol administration).

Conclusions: The results of the present study demonstrate that substantial alterations in CO as a consequence of high‐dose esmolol infusion are not associated with changes in ITBV. Because haemodynamic changes were induced by factors other than variation of preload, these findings suggest that changes in cardiac output do not influence thermodilution measurements of ITBV in this setting.
Interactions of halothane with isoproterenol and epinephrine on canine epicardial conduction velocity at normal and elevated potassium levels
Authors: Camara A. K. S. , Turner L. A. , Bosnjak Z. J.
Published: March 2003

Background: Halothane is known to potentiate catecholamine‐induced depression of conduction velocity in Purkinje fibers but not endocardial muscle fibers. The purpose of this study was to examine the interactions of halothane with epinephrine and isoproterenol on canine epicardial conduction velocity at moderately elevated extracellular potassium concentration ([K]0).

Methods: Epicardial muscle strips (10×10×2 mm) were superfused with Tyrode’s solution containing 4 or 8 mM [K]0 in the presence of 5 μM epinephrine or 1 μM isoproterenol with or without 0.8 mM halothane. Conduction velocity in the longitudinal and transverse directions relative to epicardial fiber orientation was recorded during alternate stimulation in each direction.

Results: In the presence of halothane, a change from 4 to 8 mM [K]0 decreased (P≤0.05) longitudinal and transverse conduction velocities by 26% and 21%, respectively. Isoproterenol alone at 4 and 8 mM [K]0 depressed (P<0.05) both longitudinal and transverse conduction velocities. However, the depression of longitudinal conduction velocity by isoproterenol at 4 mM [K]0 was attenuated by halothane. Epinephrine with or without halothane depressed (P<0.05) both longitudinal and transverse conduction velocities at 8 but not at 4 mM [K]0.

Conclusion: The results do not support a synergistic interaction between halothane and epinephrine on myocardial conduction but do demonstrate depression of conduction by epinephrine at 8 mM [K+]0, a potassium ion concentration comparable to those reported following epinephrine infusions.
Epidural washout with high volumes of saline to accelerate recovery from epidural anaesthesia
Authors: Rodríguez J. , Rodríguez V. , Naveira A. , Quintela O. , Bárcena M. , Gallardo E. , Gude F. , Álvarez J.
Published: March 2003

Background: Prolonged postoperative blockade can follow neuraxial blocks for short surgical procedures. We investigated whether washout with a high volume of saline through an epidural catheter could provide a faster recovery after epidural anaesthesia.

Methods: Thirty patients were randomly assigned to a control group (no washout), to group 2× (epidural washout with twice the volume of 2% mepivacaine) and group 4× (epidural washout with four times that volume).

Results: Recovery times from sensory blockade at L2 were 151±24, 122±29 and 116±24 min for control, 2× and 4× groups respectively. Significant differences were found in both saline groups when compared with control group, but not between group 2× and group 4×. No differences were found concerning motor blockade. One patient in group 4× demonstrated signs of intracranial hypertension. Mepivacaine plasma concentrations were increased by saline washout in group 4×.

Conclusions: Epidural washout with a high volume of saline can not be recommended since no clinically significant reduction in the recovery time can be achieved without risk.