bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
Perineural antinociceptive effect of opioids in a rat model
Authors: Grant G. J. , Vermeulen K. , Zakowski M. I. , Langerman L. 
Published: March 2003

Background: The research on conductive analgesia induced by perineural opioids generated a large body of conflicting data. In this study we reassessed the antinociceptive response to perineural administration of morphine, fentanyl or meperidine in a rat model.Methods: Analgesia was assessed using the hind paw withdrawal latency (HPWL) response to radiant heat. The opioid dose producing 20% of maximal possible effect (20%MPE) for systemic analgesia was calculated for each drug. Then sciatic blockade was performed with the dose corresponding to 20%MPE. The injected hind paw was used to measure direct perineural effect and the contralateral hind paw was used as an indicator of systemic effect.Results: The response latency produced by morphine or fentanyl was not significantly different for ipsilateral (perineural effect) or contralateral (systemic effect) paw (27±11 vs 28±16 and 3l±16 vs 23±16 s, respectively). However, the meperidine group showed significantly higher %MPE for the ipsilateral paw (79±32 s) than for the contralateral paw (27±22 s).Conclusions: The results indicate that perineural fentanyl or morphine do not produce analgesia. Perineural block produced by meperidine was attributed to local anesthetic‐like effect, rather than to drug interaction with opioid receptor.
Plasma concentrations and pharmacokinetics of bupivacaine with and without adrenaline following caudal anaesthesia in infants
Authors: Hansen T. G. , Morton N. S. , Cullen P. M. , Watson D. G. 
Published: March 2003

Background: The aim of this study was to determine whether the use of adrenaline 1/400 000 added to 0.25% bupivacaine significantly delays the systemic absorption of the drug from the caudal epidural space in young infants.Methods: Fifteen infants less than 5 months of age undergoing minor lower abdominal procedures under a standardised general anaesthetic were randomised to receive a caudal block with either 0.25% plain bupivacaine 2.5 mg/kg (n=7) or bupivacaine 0.25% with 1/400 000 adrenaline (n=8). Blood samples were drawn at 30, 60, 90, 180, 240 and 360 min according to the infant’s weight and analysed for total and free bupivacaine concentrations using a gas chromatography‐mass spectrometry (GC‐MS) technique.Results: The total CMAX and TMAX were comparable in both groups. The total bupivacaine concentration at t=360 min was significantly higher in the “adrenaline” group compared to the “plain” group, i.e. a median (range) 742 ng/ml (372–1423 ng/ml) vs. 400.5 ng/ml (114–446 ng/ml), P=0.0080. The median “apparent” terminal half‐life (t½) was significantly longer in the “adrenaline” group (363 min; range 238–537 min) compared to the “plain” group (n=6) (165 min; range 104–264 min), P=0.0087. The free bupivacaine concentrations (n=3 in both groups) ranged between 13 ng/ml and 52 ng/ml, corresponding to a percentage of free bupivacaine between 1.3% and 6.7%.Conclusion: The addition of 1/400.000 adrenaline prolongs the systemic absorption of caudally administered bupivacaine in infants less than 5 months of age.
Complaints related to respiratory events in anaesthesia and intensive care medicine from 1994 to 1998 in Denmark
Authors: Rosenstock C. , Møller J. , Hauberg A. 
Published: March 2003

Background: In Denmark, a National Board of Patients’ Complaints (NBPC) was founded in 1988. This study analyses anaesthetic complaints related to adverse respiratory events filed at the NBPC from 1994 to 1998 to point out directions for possible preventive measures.Methods: All decisions made by the NBPC from 1994 to 1998 concerning personnel employed in the Danish health care system were scrutinized. Cases related to anaesthesia and intensive care medicine were reviewed. Adverse respiratory events were identified and classified by mechanism of the incident that had caused the complaint. Detailed information on anaesthetic technique, personnel involved, sequence of events, clinical manifestation of injury, and outcome was recorded.Results: A total of 284 cases was identified. One‐fifth (n=60) of the complaints were related to an adverse respiratory event. The overall mortality in these cases was 50% (n=30). In 19 complaints (32%), the treatment was considered substandard.Conclusion: Complaints related to respiratory events reveal that inadequate anaesthetic and intensive care medicine treatment leads to patient damage and death. Preventive strategies should be directed at the development of guidelines for handling the difficult airway, education in the management of the difficult airway, instruction in the correct use of anaesthetic equipment, improvement of interpersonnel communication routines, as well as implementation of simulator training.
Myopexy (Faden) results in more postoperative vomiting after strabismus surgery in children
Authors: Saiah M. , Borgeat A. , Ruetsch Y. A. , Seifert B. , Klainguti G. 
Published: March 2003

Background: Strabismus correction in children is associated with a high incidence of postoperative nausea and vomiting. The purpose of this prospective, double‐blind study was to examine the influence of the surgical method for correction of squint on the incidence of postoperative vomiting.Methods: One hundred and twenty consecutive children aged 2–12 years, scheduled for elective strabismus surgery, were enrolled in this prospective, double‐blind study. A standardised total intravenous anaesthesia was given to all children. The development of perioperative oculocardiac reflex was noted and the number of episodes of vomiting during the first 48 h postoperatively was recorded. At the completion of the study, the children who were operated with myopexy according to Faden, were allocated to a Faden group, those without a myopexy to the non‐Faden group. All the patients included in this study were operated on by the same surgeon with standardised techniques.Results: The Faden group was younger, lighter and the operation time was longer (P<0.05). The incidence of vomiting was greater in the Faden group; 53% versus 12% (P<0.05). The incidence of oculocardiac reflex was similar in both groups; 40% in the Faden versus 28% in the non‐Faden group, respectively. The total dose of propofol and alfentanil was similar between the groups. Requirement of analgesics for postoperative pain was similar in both groups. The only independent risk factor for postoperative vomiting was the Faden operation.Conclusion: The surgical method used for strabismus correction in children has a great influence on the incidence of postoperative vomiting. The Faden operation is associated with a very high incidence of postoperative vomiting; this particular group of patients has to be considered as a high risk group for postoperative vomiting and deserves an antiemetic prophylaxis.