bluuebunny/crossref_metadata_2025 huggingface dataset:
Split‐dose atropine versus glycopyrrolate with neostigmine for reversal of gallamine‐induced neuromuscular blockade
Authors: Wetterslev J. , Jarnvig I. , JøoSrgensen L. N. , Olsen N. V.
Published: January 2009

The effects of a split‐dose of atropine sulphate versus a single dose of glycopyrrolate given with neostigmine for the reversal of gallamine‐induced neuromuscular blockade were studied in 55 patients undergoing gynaecological surgery. The patients were randomized to receive either a single dose of glycopyrrolate (7 μg ‐ kg‐1) or two doses of atropine (8 μg ‐ kg‐1 each), given with an interval of 1 min. There were no differences between the two methods with respect to percentage heart rate changes, salivation or arousal time. Four patients demonstrated cardiac arhythmias in the atropine group, whereas none occurred in the glycopyrrolate group (P<0.05). It is concluded that a split‐dose of atropine has similar chronotropic effects to a single dose of glycopyrrolate for the reversal of gallamine‐induced neuromuscular blockade. However, the finding of a higher incidence of cardiac arrhythmias in the atropine group suggests that this reversal regime should be reserved for patients without cardiac disease.
Failure to demonstrate unconscious perception during balanced anaesthesia by postoperative motor response
Authors: Jansen C. K. , Bonke B. , Klein J. , van Dasselaar N. , Hop W. C. J.
Published: January 2009

Eighty patients undergoing a standardized balanced anaesthesia were randomly assigned to either a suggestion group (N = 38) or a control group (N = 42), in a double‐blind design. Anaesthesia was maintained with nitrous oxide, enflurane and fentanyl. Patients in the suggestion group were played seaside sounds, interrupted by statements of the importance of touching the ear during a postoperative visit, by means of a prerecorded audiotape and headphones. Tapes containing these suggestions were played from 30 min after the first incision, for a duration of 15 min. Patients in the control group were only played seaside sounds. There were no significant differences between the groups in either the number of patients touching their ears postoperatively or the number and duration of ear touches.
Effects of diltiazem on postischaemic renal cortical microcirculation in the pig
Authors: Sandin R. , Feuk U. , Wahlberg J. , Modig J.
Published: January 2009

Diltiazem ‐ a calcium entry blocker ‐ was tested in a porcine model under continuous chlormethiazole‐pancuronium anaesthesia as protection against renal failure following 60 min of renal ischaemia. Fourteen pigs were randomly allocated to one experimental (diltiazem and ischaemia) and one control group (only ischaemia) (n = 7 in each). Diltiazem was administered as a continuous intravenous infusion started before the ischaemic insult. In two additional animals diltiazem was given but ischaemia was not induced. The postischaemic renal cortical microcirculation was simultaneously investigated in four different regions in the left kidney during the first 4 h of reperfusion. Laser Doppler flowmetry (LDF) was performed in two different regions and measurement of tissue oxygenation was done in two other regions. In the two animals treated with diltiazem without ischaemia, only minor variations in central haemodynamic and renal microcirculatory parameters were evident. In the control group (ischaemia), superficial renal cortical blood flow (Q decreased from 49 ± 11 (s.d.) arbitrary units at baseline to 24 ± 4 arb. units 4 h after start of reperfusion (P<0.05). Simultaneously, mean Pto2 decreased from 4.5 ± 1.2 kPa to 2.4 ± 1.5 kPa (P<0.05) and the percentage of the measured Pto2 values that were <0.6 kPa (Pto2) increased from 1 ± 2% to 19 ± 25% (P<0.05). In the experimental group Q decreased from 49 ± 8 arb. units at baseline to 27 ± 10 arh. units 4 h after start of reperfusion (P<0.05). Simultaneously, mean Pto2 decreased from 4.6 ± 1.3 kPa to 3.2 ± 2.0 kPa (P<0.05) and L‐Pto2 increased from 0 to 18 ± 23% (P<0.05). No significant differences in the renal microcirculatory parameters were found between control and experimental groups at baseline or 4 h after start of reperfusion. The postischaemic reduction (P<0.05) in inulin clearance during the investigated period was also unaffected by diltiazem. Thus, we conclude that intravenous pretreatment with diltiazem, which was used in this experimental porcine model, has no beneficial influence on either superficial renal cortical microcirculation or on recovery of inulin clearance after ischaemia.
Decreased expression of class II major histocompatibility complex (MHC) molecules on monocytes is found in open‐heart surgery related immunosuppression
Authors: RyhÄaUnen P. , Surcel H.‐M. , Ilonen J.
Published: January 2009

The expression of class II major histocompatibility complex (MHC) molecules on monocytes and the relative proportion of immunoregulatory lymphocyte subpopulations were studied from the blood of eight patients undergoing a cardiac operation. The aim of the study was to reveal mechanisms responsible for depression of cellular immunity and B‐lymphocyte activation associated with open‐heart surgery. A decreased staining of HLA‐DR and even more of HLA‐DQ class II MHC molecules was found on the monocyte surface in samples taken 2 and 7 days after operation when compared to preoperative values. The relative proportion of monocytes in mononuclear cells increased after surgery, but within lymphocyte subpopulations only a decrease in total T cells and an increased number of activated (HLA‐DR positive) T cells were found, whereas the rations between various T cells subsets remained relatively stable.
Local vascular effects of isoflurane during regional intestinal hypothermia in cats
Authors: Raner Christina , Biber Björn , Henriksson Bengt‐Ake , Martner Jan , Winsö Ola
Published: January 2009

The influence of isoflurane on intestinal blood flow (IBF) during regional intestinal hypothermia (28°C intraluminal temperature) was investigated in cats (n = 12) during basal chloralose‐nitrous oxide anesthesia. A jejunal segment, which was dissected free in situ and intermittently cooled in a saline bath, was perfused via an extracorporeal arterial circuit which included a roller pump and a variable arterio‐venous shunt. Intestinal perfusion pressures were controlled by adjusting the shunt flow. IBF was measured (optical drop‐recording) during regional normothermia and hypothermia. The protocol included steady‐state recordings at defined perfusion pressures (50, 75, 100, 125 and 150 mmHg in a randomized order; 6.7, 10.0, 13.3, 16.7 and 20.0 kPa, respectively) with and without the addition of 0.7% isoflurane. During normothermia, IBF levels were higher during isoflurane anesthesia than during basal chloralose anesthesia. Regional intestinal hypothermia induced no significant changes in IBF during basal chloralose anesthesia. However, the intestinal vasodilator effects of isoflurane, as shown during normothermia, were efficiently countered by regional cooling of the intestinal segment to 28°C. Accordingly, hypothermia IBF levels were similar, regardless of whether isoflurane was administered or not. This could have an impact on the choice of anesthetic techniques.
Premedication before elective breast surgery, a comparison between ketobemidone and midazolam
Authors: Jakobsson J. , Andersson L. , Nilsson A. , Davidson S. , Askergren J.
Published: January 2009

One hundred female patients scheduled for elective breast surgery (mean age 60 ± 11 years) were randomly assigned to receive one of two premedications: ketobemidone (Ketogan®) 1‐1.5 ml or midazolam 4–5 mg, intramuscularly. The effects on preoperative anxiety and postoperative emetic sequelae were studied. All patients were anaesthetised with thiopentone, fentanyl and atracurium, and ventilated with a mixture of nitrous oxide in oxygen with supplementary isoflurane. Sixty‐nine percent of the midazolam‐ and 50% of the ketobemidone‐premedicated patients experienced a reduction in anxiety. Midazolam was found to be more effective than ketobemidone in reducing anxiety among more tense patients ‐ those with a VAS grading before premedication of 2 or more (P<0.05). Midazolam‐premedicated patients were also assessed by observers as being more relaxed (P<0.05). No difference was seen in the frequency of emetic sequelae: 20 patients in the midazolam group and 14 patients in the ketobemidone group vomited once or more during the 24‐h observation period. There was no difference between the two groups in time until an analgetic was required. In conclusion, midazolam seemed more effective in reducing preoperative anxiety than ketobemidone without any negative effects on postoperative emesis or time until an analgetic was required.
Basic studies of pulse oximetry in a rabbit model
Authors: Vegfords M. , Sjöberg F. , Lindberg L.‐G. , Gustafsson U. , Lennmarken C.
Published: January 2009

We have developed an animal model for the evaluation of pulse oximetry during severe hypoxaemia. Twelve rabbits were anaesthetized and mechanically ventilated via a tracheostomy tube. Increasing fractions of nitrogen were added to the gas mixture they inhaled to obtain severe hypoxaemia (saturation range 26%‐100%). On 412 occasions, simultaneous pulse oximeter (Spo2) and invasive haemoximeter (Sao2) measurements were compared. The regression analysis of the data gave the equation: y = 0.7 x + 26.7, r = 0.90. In the Sao2 range ≤ 85%, the bias (mean value of Sao2‐Spo2) was higher when compared with Sao2> 85%. In an in vitro study the light absorption characteristics of rabbit haemoglobin (Hb) were compared to human Hb. The millimolar extinction coefficients of both reduced and oxygenated Hb from rabbits were found to be similar to human Hb. We consider the animal model (rabbit) suitable for studies of pulse oximetry during physiological and pathophysiological conditions.
Isoflurane in nitrous oxide and oxygen increases plasma concentrations of noradrenaline but attenuates the pressor response to intubation
Authors: Randell T. , Seppälä T. , Lindgren L.
Published: January 2009

The haemodynamic response to laryngoscopy and intubation was evaluated in 52 ASA I patients anaesthetized with thiopentone 4–6 mgkg‐1. Vecuronium 0.1 mgkg‐1, followed by 3 min mask ventilation with nitrous oxide in oxygen with (isoflurane group) or without (control group) 3% inspired isoflurane preceded tracheal intubation. In 21 of 52 patients, concentrations of noradrenaline (NA), adrenaline and 3,4‐dihydroxyphenylethyleneglycol (DHPG) were measured from central venous plasma. During the 3‐min ventilation, in the isoflurane group, heart rate increased by 22% but remained stable in the control group. A marked pressor response to laryngoscopy and intubation was seen in the control but not in the isoflurane group. During the 3‐min ventilation, the plasma concentration of NA was doubled in the isoflurane group and increased by 49% in the control group (P<0.05). The concentration of DHPG also increased in the isoflurane group. Peripheral skin temperature increased similarly after 3 min ventilation in both groups. After intubation, it was significantly higher in the isoflurane than in the control group (P<0.05). In conclusion, compared to nitrous oxide in oxygen, ventilation with isoflurane in nitrous oxide in oxygen causes a sympathetic activation combined with an increase in heart rate and peripheral temperature while the pressor response to laryngoscopy and intubation is attenuated.
Nebulized corticosteroid improves pulmonary function and outcome in experimental porcine septicemia
Authors: Walther S. , Jansson I. , Gunnarsson M. , Lennquist S.
Published: January 2009

Nebulized beclomethasone dipropionate was administered to six anesthetized and artificially ventilated pigs at 6‐hourly intervals after infusion of live S. aureus (aerosol group). Changes in pulmonary mechanics, gas exchange and hemodynamics during an observation period of 44 h were compared with those in six pigs subjected to the same insults but given no corticosteroid (non‐treatment group). Six pigs served as controls, without sepsis or aerosol, but with the same general management (control group). The septic insult induced an acute 3‐fold increase in mean pulmonary artery pressure (MPAP) in the aerosol and non‐treatment group. MPAP fell to near baseline levels in the aerosol group, but remained significantly higher in the non‐treatment group. Mean systemic arterial pressure fell more in the non‐treatment than in the aerosol group, reaching its lowest level at 32 h. Pulmonary function was less affected in the aerosol group, with significantly better maintenance of arterial oxygenation, lower venous admixture and superior lung‐thorax compliance than in the non‐treatment group. Survival was significantly improved in the aerosol group. In this porcine model of septicemia‐induced adult respiratory distress syndrome, nebulized corticosteroid thus attenuated the development of respiratory failure.
Albumin, HES 120 and dextran 70 as adjuvants to red blood cell concentrates: a study on colloid osmotic pressure changes in vitro
Authors: Hiippala S. , Linko K. , Myllylä G. , Lalla M. , Mäkeläinen A.
Published: January 2009

An in vitro model of surgical bleeding was developed to simulate continuous blood loss and replacement therapy with plasma substitutes and red cell concentrates. The model was used to determine the lowest colloid concentration in vitro for each of the plasma substitutes that sustains colloid osmotic pressure above 2.4 kPa (or 18 mmHg) when used up to the recommended maximal total dose. Plasma, supernatant separated from red cell concentrates and dextran 70, hydroxyethyl starch 120 or albumin were mixed to create dilutions imitating plasma composition in the course of clinical blood loss and replacement therapy. The relative volume of each component was calculated according to the model when the bleeding was equal to multiples of 10% of blood volume up to a blood loss of 120%. Our measurements indicate that the colloid concentrations of 5.0% for albumin, 4.0% for hydroxyethyl starch 120 and 3.5% for dextran 70 preserve colloid osmotic pressure above 2.4 kPa.
Haemodynamic effects of heparin during coronary bypass surgery
Authors: Kongsgaard U. E. , Smith‐Erichsen N. , Hysing E. , Tølløfsrud S. , Seem E. , Geiran O. , Bjørnskau L.
Published: January 2009

Heparin has been suggested as an activator of the plasma kallikrein‐kinin system, with possible formation of bradykinin, a potent vasodilator. Haemodynamic effects and changes in the kallikrein‐kinin system were studied after heparin‐ and saline‐injections in ten patients undergoing coronary bypass surgery. A moderate decrease in mean arterial pressure was found in all patients in the observation period, but significantly more at 2 and 3 min after heparin‐injection compared with saline‐injection. None of the other haemodynamic variables measured were significantly different when comparing heparin‐ to saline‐injection. Heparin‐injection resulted in significant changes in the kallikrein‐kinin system, with a marked increase in spontaneous kallikrein‐like activity as the most prominent feature, while no changes were found after saline‐injection. Liberation of bradykinin would be expected to give a decrease in systemic vascular resistance with an increase in cardiac output. The results indicate that the plasma kallikrein‐kinin system, though apparently activated after heparin‐injection, does not contribute significantly to the decrease in arterial pressure in the patients studied.
CVP catheter electrocardiography: an alternative to radiographic control after cannulation of central veins?
Authors: Koscielniak‐Nielsen Z. J. , Otkjær S. , Hansen O. B. , Hemmingsen C.
Published: January 2009

We evaluated 160 electrocardiograms taken after placement of central venous catheters (CVC) to determine their locations. Usable recordings were obtained in 154 patients. Subsequent radiographs revealed 30 misplaced catheters. Twenty‐five of those were detected by CVC electrocardiograms. There were five false positive and five false negative traces. The sensitivity of CVC electrocardiography was 96%, the specificity 83.3%, and the total predictive power 93.5%. Electrocardiograms obtained from guide‐wires were of significantly better quality than those from 0.9% NaCl filled catheters. The technique is accurate, safe and easy to learn. It may reduce the need for routine radiographic control to less than 10% of patients.
Opioid supplementation to propofol anaesthesia for outpatient abortion: a comparison between alfentanil, fentanyl and placebo
Authors: Jakobsson J. , Davidson S. , Andreen M. , Westgreen M.
Published: January 2009

One hundred and sixty‐four patients scheduled for elective termination of pregnancy under general anaesthesia were randomly assigned to receive one of three different supplements to propofol and oxygen in nitrous oxide anaesthesia: 0.1 mg fentanyl, 0.5 mg alfentanil or placebo. Postoperative pain and nausea, as well as complications during anaesthesia were studied. There were no differences in complications or complaints by surgeons during anaesthesia, and no patient in any group reacted unsatisfactorily to surgery. The patients in the placebo group consumed significantly more propofol during the procedure (P<0.001). No differences were seen in time until hospital discharge between the three groups. Complaints about postoperative pain were significantly less frequent among patients receiving fentanyl (P<0.01). The number of patients requesting postoperative analgetics, however, did not differ. There was no difference in the frequency of nausea or vomiting, but postoperative pain was found significantly to increase complaints of nausea (P<0.01) and also time until hospital discharge (P<0.01). In conclusion, opioid supplementation lowered the amount of propofol needed for anaesthesia. Alfentanil 0.5 mg did not improve the postoperative course. Fentanyl 0.1 mg decreased the frequency of postoperative pain without increasing the time to hospital discharge.
Lung surfactant in respiratory distress syndrome
Authors: Hallman Mikko
Published: January 2009

Severe respiratory failure is always associated with a defect in the surfactant system. Surfactant substitution in newborn infants with respiratory distress syndrome (RDS) has gained worldwide acceptance. In the present study, we have evaluated whether surfactant diagnostics are of use in choosing recipients of exogenous surfactant. In addition, we studied whether factors apparently unrelated to surfactant influence the degree of respiratory failure and surfactant responsiveness. In small preterm infants, the surfactant indices in amniotic fluid (L/S ratio and phosphatidylglycerol), within 3 days of birth, predicted the risk of RDS with a sensitivity of 90–100%, and a specificity of 50–85%. The surfactant indices, measured in BAL, predicted the risk of ARDS (which became evident 1 to 7 days later) with a sensitivity of 50–60% and a specificity of 59–65%. In small preterm infants with RDS, the amount of fluids given during the first day correlated positively with the degree of respiratory failure and negatively with the degree of surfactant responsiveness. According to an experimental study, in hydrostatic lung edema, exogenous surfactant is diluted by edema fluid and becomes sensitive to inhibitors of surfactant function. Beside dosage, quality, and time of administration, the management of patients largely dictates the responsiveness to exogenous surfactant.
Surfactant inactivation and surfactant replacement in experimental models of ARDS
Authors: Robertson Bengt
Published: January 2009

Lung structure and function, and the effect of surfactant replacement, were studied in three animal models of adult respiratory distress syndrome (ARDS): surfactant depletion by repeated lung lavage, proteinaceous pulmonary edema induced by prolonged exposure to hyperoxia, and inoculation with hybridoma making an antibody to the hydrophobic surfactant‐associated protein, SP‐B. Surfactant replacement therapy restored normal gas exchange in respiratory failure induced by repeated lung lavage but was ineffective in animals with severe lung parenchymal lesions induced by hyperoxia or antibody to SP‐B. Lung edema fluid from animals exposed to hyperoxia inhibited surfactant function in a concentration‐dependent manner. These observations indicate that, in experimental ARDS, the effect of surfactant replacement depends on the type of animal model and, especially, on the degree of lung injury present at the time of therapy.
Disseminated intravascular coagulation
Authors: Risberg Bo , Andreasson Svenerik , Eriksson Elsa
Published: January 2009

This review encompasses a description of the main pathophysiological events leading to disseminated intravascular coagulation (DIC). Emphasis has been put on microcirculatory disturbances and endothelial dysfunction. The normal hemostatic functions of the vascular endothelium are described. The close connection between endothelium and superimposed immuno‐modulators is stressed as is the interrelation between the proteolytic cascade systems in the blood. The importance of differentiating local and systemic events is discussed. Organ dysfunction in multiple organ failure (MOF) is exemplified by pulmonary insufficiency in the adult respiratory distress syndrome (ARDS). Essential laboratory tests of DIC are described as are the cornerstones of treatment.
Oxygen radicals and lung injury
Authors: Risberg B. , Smith L. , Örtenwall P.
Published: January 2009

This article describes the formation of oxygen radicals and their biological effects, especially in relation to lung injury. Various recent experimental data are reviewed. The relationships between hydrostatic effects and permeability effects in producing injury and edema are stressed. Means of prevention and problems related to extrapolation to clinical situations are focused.
Epidural bupivacaine, sufentanil or the combination for post‐thoracotomy pain
Authors: Mourisse J. , Hasenbos M. A. W. M. , Gielen M. J. M. , Moll J. E. , Cromheecke G. J. E.
Published: January 2009

Analgesia with epidural bupivacaine, sufentanil or the combination was studied in 50 patients who had undergone thoracotomy. During operation all patients received an initial dose of bupivacaine 0.5% with adrenaline 5 μg±ml‐1 (5–10 ml) by thoracic epidural catheter. One hour later the patients were divided into three groups: the bupivacaine group (bupivacaine 0.125%), the sufentanil group (50 μg sufentanil in 60 ml normal saline) and the combination group (50 μg sufentanil in 60 ml bupivacaine 0.125%). Analgesia in the three groups was provided by a continuous epidural infusion (5–10 ml±h‐1) for 3 days. The mean dose of bupivacaine was significantly higher (P<0.05) in the bupivacaine group (12.07 mg±h‐1 (s.e.mean 0.97 mg±h‐1)), compared with the combination group (9.82 mg±h‐1 (s.e.mean 0.43 mg±h‐1)). The mean dose of sufentanil in the sufentanil group was similar to the combination group (6.37 μg±h‐1 (s.e.mean 0.23 μg±h‐1) and 6.52 μg±h‐1 (s.e.mean 0.28 μg±h‐1), respectively. The pain scores on the inverse visual analogue scale of most patients in the bupivacaine group were unacceptably low. The sufentanil group had much better pain scores, but on exercise these patients experienced more pain than the combination group. The combination group had, overall, better pain scores. In the combination group, there were better respiratory results.
Does the anesthetic method influence the postoperative breathing pattern and gas exchange in hip surgery? A comparison between general and spinal anesthesia
Authors: Tulla H. , Takala J. , Alhava E. , Hendolin H. , Manninen H. , Kari A. , Suomalainen O.
Published: January 2009

We studied the effects of elective hip surgery, performed under either spinal (SA, n = 10) or general anesthesia (GA, n = 10), on breathing pattern and gas exchange. Measurements were made with respiratory inductive plethysmograph and indirect calorimetry in two positions before and after surgery. The method of anesthesia had no effect on the severity of postoperative hypoxemia. Reduced arterial oxygenation (Pao2; P<0.001, SA from 12.5±2.37 kPa to 10.5±1.38 kPa, GA from 12.5±2.95 kPa to 10.5±1.75 kPa) despite increased alveolar ventilation (P<0.01; from 2.30±0.37 1/min to 2.39±0.43 1/min in SA, 2.27±0.56 1/min to 2.57±0.35 1/min in GA) and reduced arterial carbon dioxide partial pressure (Paco2; SA from 5.20±0.22 kPa to 4.95±0.33 kPa, P<0.01, GA from 5.07±0.36 kPa to 4.72±0.41 kPa, P<0.05) indicated maldistribution of ventilation and perfusion. Changes in breathing pattern and gas exchange and differences between the groups were minimal. Minute ventilation, tidal volume and mean inspiratory flow remained unchanged in both groups. The contribution of rib cage to tidal volume increased postoperatively in the supine position (P<0.001; SA from 32.6%±10.3 to 46.3%±7.5, GA from 36.5±16.4 to 48.5%±15.4). CO2 production, oxygen consumption and energy expenditure remained unchanged. The postoperative changes in breathing pattern are related to the operation, not to the type of anesthesia and do not explain the alterations in gas exchange.
Effects of anaesthesia and surgery on the immune response
Authors: Salo M.
Published: January 2009

Alterations have been found to occur in every component of immune response during anaesthesia and surgery. These alterations represent the body's general physiological responses and are mainly dependent on the extent of surgery, as well as other factors such as the patient's age and health status, medication and blood transfusion. Anaesthetic and operative complications have profound effects on these responses. Basically, the immune response to anaesthesia and surgery is a beneficial reaction, needed in local host defences and wound healing and in preventing the body from making autoantibodies against its own tissues. The responses may, however, contribute to the development of postoperative infections and spread of malignant disease. During uncomplicated conventional surgery, the immune response usually passes clinically unnoticed without any harmful effects. Absent responses and excessively high responses, on the other hand, harm the patient. Our understanding of immunological phenomena and our possibilities of controlling mediator activation are now lagging behind the technical advances made in operative treatment. If we want to decrease operative morbidity and mortality to below their present levels, more attention should be directed to immune responses to major surgery, injuries and operative complications with massive mediator release which place the surgical patient at risk. Experimental evidence suggests that results of treatment in injured and operated patients can in the future be improved by controlling immune responses and their mediator systems. Our current level of knowledge of immune responses is already helping us to avoid many immune‐mediated complications. However, routine interference with these responses is not indicated.
Measurement of lower oesophageal pH during induction of anaesthesia: use of oesophageal probe
Authors: Martin C. , Auffray J. P. , Ragni J. , Guillen J. C. , Auge A. , Lambert D. , Gouin F.
Published: January 2009

Gastric contents regurgitation into the oesophagus during induction of anaesthesia may easily fail to be recognized. The incidence of this complication was investigated in 59 consecutive patients. They were scheduled for elective thoracic surgery. Anaesthesia was induced with thiopentone (6 mg ± kg‐1), fentanyl (3 μg ± kg‐1), and either atracurium (0.4 mg ± kg‐1), vecuronium (0.1 mg ± kg‐1) or suxamethonium (1.5 mg ± kg‐1). Oesophageal pH was monitored with an oesophageal pH probe, connected to a portable computer. The pH probe had a virtually instantaneous response time and was positioned in the lower oesophagus. Acid reflux was defined as a decrease in pH to less than 4.0. During the course of induction, three patients (5%) presented an episode of acid reflux. No patient presented any clinical or radiological signs of pulmonary aspiration. This study suggests that monitoring oesophageal pH is a simple method of detecting gastric reflux during the period of induction.
The influence of naloxone infusion on the action of intrathecal diamorphine: low‐dose naloxone and neuroendocrine responses
Authors: Wright P. M. C. , O'Toole D. P. , Barron D. W.
Published: January 2009

The influence of an intravenous infusion of naloxone 1 μg kg‐1h‐1, in combination with intrathecal diamorphine, on analgesia and hormonal stress responses after laminectomy was assessed in a blinded, randomized, placebo‐controlled study. Twenty‐seven patients undergoing laminectomy with postoperative analgesia provided by intrathecal diamorphine were investigated. Analgesia was reduced by naloxone (P<0.05), and the duration of analgesia was shortened by 180 min. The postoperative concentrations of both blood glucose and serum cortisol were reduced in the naloxone group compared to the control group (P<0.05). These results may indicate an excitatory role for the hypothalamic μ receptor in hypothalamo‐pituitary‐adrenocortical axis regulation.
Haemoglobin dilution from epidural‐induced hypotension with and without fluid loading
Authors: Hahn R. G.
Published: January 2009

The blood haemoglobin concentration (B‐Hb) was measured repeatedly to reflect dilution or concentration changes of the blood during onset of lumbar epidural anaesthesia in 90 elderly men. With crystalloid volume loading (10 ml ± kg‐1 b.w.), the decrease in B‐Hb was twice as great for those who developed hypotension during the onset of the blockade as for patients whose arterial pressure remained normal (P<0.001), both when epidural anaesthesia was induced with plain mepivacaine, and when mepivacaine plus adrenaline was used. In a control group where no fluid loading was performed, there was no consistent change in the haemoglobin level, irrespective of blood pressure reaction to the blockade. The results suggest that crystalloid fluid loading allows an increase in blood volume in epidural‐induced hypotension.
Total intravenous anaesthesia for direct laryngoscopy: propofol infusion compared to thiopentone combined with midazolam and methohexitone infusion
Authors: Sonne N. M. , Clausen T. G. , Valentin N. , Halck S. , Munksgaard A.
Published: January 2009

Total intravenous anaesthesia for direct laryngoscopy was investigated in 40 patients, randomized into four groups of 10 patients each. First, propofol infusion was compared to thiopentone combined with midazolam. Next, a comparison of propofol infusion with methohexitone infusion was undertaken. The propofol group showed significantly lower peroperative blood pressure compared to the thiopentone/midazolam group. The second propofol group required significantly less alfentanil to stabilize the blood pressure, compared to the methohexitone group. Completeness of recovery, assessed by means of a coin counting test, was faster in the propofol group compared to the thiopentone/midazolam group, while no difference could be demonstrated between the second propofol group and the methohexitone group. It is concluded that propofol seems to be superior to both thiopentone/midazolam and methohexitone with respect to the stability of peroperative blood pressure. Concerning recovery, propofol is superior to thiopentone/midazolam, but offers no advantage over methohexitone.
Prophylactic diclofenac infusions in major orthopedic surgery: effects on analgesia and acute phase proteins
Authors: Claeys M. A. , Camu F. , Maes V.
Published: January 2009

The influence of diclofenac, given by continuous i.v. infusion starting preoperatively, on postoperative pain and inflammation was assessed in a double‐blind, randomized, placebo‐controlled study in 40 patients scheduled for major orthopedic surgery. Starting 30 min before induction the patients received either diclofenac (0.35 mg.kg‐1 bolus followed by a constant‐rate infusion of 90 μ.min‐1) or placebo for 24 h. The pain intensity (VAS) and the amount of rescue narcotic (piritramide on demand) were significantly lower in the diclofenac group from 4 and 6 h postsurgery, respectively, till end of infusion. Acute phase proteins used as inflammation markers (C‐reactive protein, α1‐chymotrypsin, α1‐acid glycoprotein, haptoglobin and coeruloplasmin) showed similar variations in both groups for 24 h. The diclofenac treatment had no influence on hematological and coagulation profiles, nor on muscle and liver enzymes in comparison with placebo. Both patients and observer rated the diclofenac treatment as significantly superior to the placebo treatment.
Psychomotor recovery following propofol or isoflurane anaesthesia for day‐care surgery
Authors: Larsen L. E. , Gupta A. , Ledin T. , Doolan M. , Linder P. , Lennmarken C.
Published: January 2009

A newly developed test for the assessment of psychomotor recovery ‐ the perceptive accuracy test (PAT) ‐ is described. Seventy‐four subjects who performed the test thought that it was easy to perform and some were motivated to try it on a number of occasions. Eight persons performed the test on different days and at different periods of time; the results were consistent and reproducible. Eight more persons were then asked to do the test 4 times at 15‐min intervals; no ‘learning’ was seen with this test. A randomized, prospective study was then performed in two groups of 15 patients, undergoing arthroscopic procedures of the knee. Anaesthesia was induced with propofol and maintained with an infusion of propofol 12 mg/kg/h for the first 15 min, followed by 8 mg/kg/h subsequently in the propofol group. In the isoflurane group, anaesthesia was also induced with propofol, but isoflurane (0.5‐2%) was used to maintain anaesthesia. Alfentanil was the analgesic used in both groups of patients. Results were compared with a third group of unanaesthetised controls, who were asked to perform psychomotor tests including choice reaction time and PAT at 30‐min intervals for 2.5 h. There was a significant difference (P<0.01) in psychomotor recovery on the PAT‐200 between the propofol group and control groups, but not in the isoflurane and control groups at 30 min. Both groups had returned to baseline values at 60 min in the PAT‐60 and PAT‐200. The choice reaction time showed no significant difference in either group 30 min after the anaesthetic. Results indicate that there is no ‘learning’ with the newly developed PAT, although this was significant with the choice reaction time. This study indicates that psychomotor recovery following isoflurane anaesthesia is quicker than that following propofol. The perceptive accuracy test appears to be a good and sensitive test for the assessment of recovery following day‐care anaesthesia.
Myocardial circulatory and metabolic effects of halothane when used to control intraoperative hypertension in patients with coronary artery disease
Authors: Sahlman L. , Milocco I. , Ricksten S.‐E.
Published: January 2009

The effect of halothane on regional myocardial metabolism and blood flow, when used as an adjunct to fentanyl‐nitrous oxide anaesthesia, to treat intraoperative hypertension was investigated. Fifteen patients with two‐ or three‐vessel coronary artery disease with an ejection fraction >0.5 and on beta‐blockers up to the morning of surgery were studied during elective coronary artery by‐pass grafting. Systemic and pulmonary haemodynamics, global (coronary sinus, CSF) and regional (great cardiac vein, GCVF) myocardial blood flow were measured. Measurements were made: 1) after induction of anaesthesia but prior to skin incision, 2) during sternotomy, and 3) during halothane administration after its use to reduce arterial pressure to the pre‐sternotomy level. The increase in systemic arterial pressure during sternotomy was due to an increase in systemic vascular resistance index (SVRI), and was accompanied by an increase in pulmonary capillary wedge pressure (PCWP), regional myocardial oxygen consumption and extraction, GCFV and CSF. Halothane reduced arterial blood pressure to pre‐sternotomy levels within 7.1 ± 0.6 min at an end‐tidal concentration of 0.96 ± 0.11%. Halothane caused a decrease in SVRI, total coronary vascular resistance, regional myocardial oxygen consumption and extraction, while cardiac index, heart rate and GCVF/CSF ratio remained unchanged. Mean regional myocardial lactate extraction was not affected by sternotomy or halothane. During halothane administration one patient developed regional myocardial lactate production which was not present during sternotomy. However, another two patients, who had regional myocardial lactate production during sternotomy, did not produce lactate or had less negative value of regional myocardial lactate extraction during halothane administration.
Technical problems associated with the use of 32‐gauge and 22‐gauge spinal catheters
Authors: Silvanto M. , Pitkänen M. , Tuominen M. , Rosenberg P. H.
Published: January 2009

Interest in the use of continuous spinal anaesthesia (CSA) has recently increased because of the availability of new, extremely thin catheters. In this study the use of 32‐gauge (G) catheters was compared with 22‐G catheters in operations on the lower limb and for the administration of intrathecal morphine in the postoperative period in 42 elderly patients. CSA succeeded in 34 cases and 8 patients were anaesthetised with a single‐shot spinal method. No general anaesthesia was needed. Technical problems with the subarachnoid puncture with the 19‐G needle caused two failures in the 22‐G group. In a group of 20 patients, there were five failures with the 32‐G catheter, as opposed to one failure with the 22‐G catheter in a group of 20 patients. Associated with morphine injection through the 32‐G catheter, the syringe or connector was inadvertently disconnected in four cases and a tear of the catheter wall was observed in one case. Such problems did not occur with the 22‐G catheter. Postdural puncture headache did not occur, and there was no difference in the incidence of patient‐reported postoperative complications between the two groups. It is concluded that both the insertion and maintenance of the thin (32‐G) subarachnoid catheters are associated with more technical problems than the 22‐G catheter.
Effect of alpha‐chloralose, halothane, pentobarbital and nitrous oxide anesthesia on metabolic coupling in somatosensory cortex of rat
Authors: Ueki M. , Mies G. , Hossmann K.‐A.
Published: January 2009

The effect of various anesthetics on the functional‐metabolic coupling of cerebral cortex was studied in rats submitted to unilateral somatosensory stimulation. The regional cerebral metabolic rate of glucose (CMRglc) was measured autoradiographically using the 2‐deoxyglucose method, and somatosensory activation was carried out by electrical stimulation of the left forepaw. In animals treated with 70% nitrous oxide, 0.5% halothane/70% nitrous oxide or 40 mg/kg pentobarbital, CMRglc of somatosensory cortex did not change despite generation of primary evoked cortical potentials. Anesthesia with 80 mg/kg alpha‐chloralose, in contrast, led to a focal increase of CMRglc in the primary somatosensory cortex from 52.1 ± 18.3 to 73.1 ± 18.9 μmol/100 g/min (means ± s.d.). Metabolic activation was strictly confined to the forelimb (FL) area of somatosensory cortex, and it exhibited a laminar pattern with maximal activation in layers I, II and IV. The preservation of functional‐metabolic coupling under a surgical dose of chloralose renders this anesthetic particularly suited for the investigation of coupling processes under conditions where the experimental requirements preclude the use of unanaesthetized animals.
Intrapulmonary thrombin generation and its relation to monomethylmethacrylate plasma levels during hip arthroplasty
Authors: Dahl O. E. , Johnsen H. , Kierulf P. , Molnar I. , Rø J. S. , Vinje A. , Mowinckel P.
Published: January 2009

Frequent peroperative sampling of arterial and mixed venous blood was undertaken in eight consecutive patients during cemented hip arthroplasty to obtain a sequential picture of thrombin‐antithrombin (TAT) and methylmethacrylate monomer (MMA) concentrations. TAT, detected neo‐antigenically, reached its maximum levels after bone preparation, prior to introduction of cement and prosthesis. Furthermore, TAT values were higher in arterial than in mixed venous blood, indicating generation and inactivation of thrombin when blood is passing the lung. MMA concentration, measured by high pressure liquid chromatography, increased very rapidly and declined within 1 min following socket as well as shaft implantation, reaching the highest mean value of 3599 ng/ml only 30 s after femoral impaction of cement. MMA concentration was higher in mixed venous than in arterial blood, indicating elimination of the monomer during lung passage. This study confirms our previous observation that coagulation is activated prior to the implantation of bone cement and prosthesis into the femoral shaft; in addition, it provides further evidence of the thrombin‐generating potential of the pulmonary capillary bed. Very frequent sampling was necessary to reveal the sharp rise in MMA levels following impaction of cement. Further investigations are needed to establish whether interaction between activated coagulation and MMA may predispose to cardiovascular complications.
The influence of changes in blood flow on the accuracy of pulse oximetry in humans
Authors: Vegfors M. , Lindberg L.‐G. , Lennmarken C.
Published: January 2009

Oxygen saturation (Spo2) was measured with a pulse oximeter in ten healthy, young men breathing air. A pulse oximeter probe was attached to the second toe and a laser Doppler probe to the first toe of the same foot for measurement of changes in peripheral blood flow. The pulse oximeter and laser Doppler readings were simultaneously compared when the foot was positioned 40 cm (position 1) above heart level, elevated 10 cm (position 2) above heart level and horizontally at heart level (position 3). Using this experimental human model, we achieved various blood flows. The AC and DC optical signals used for determination of oxygen saturation were recorded from the pulse oximeter and analysed. There was a significant increase (P<0.05) between position 1 and 3 in blood flow as measured by the laser Doppler flow meter. The corresponding pulse oximeter readings of haemoglobin saturation also increased significantly (P<0.05) comparing these two leg positions. Analysing the AC‐ and DC optical signals, the AC value of infrared light increased considerably, while the AC value of the red light decreased slightly. The DC values of red and infrared light did not change significantly. In summary, when blood flow was decreased, the ratio of red to infrared transmitted light was changed, resulting in a low Spo2 reading.
Capsaicin pretreatment of rats does not prevent tissue extravasation of albumin from intraabdominal trauma
Authors: Åkerström G. , Lisander B.
Published: January 2009

Intra‐abdominal surgery causes a loss of plasma into tissues within and around the abdomen, predisposing to a decreased tissue viability and postoperative complications. In a rat model of intra‐abdominal trauma, we investigated whether neuropeptides released from thin afferent nerve endings may contribute to this extravasation. Newborn male Wistar rats were pretreated with capsaicin 50 mg/kg s.c., leading to a lifelong degeneration of thin afferents. The same animals, when adult, were subjected to experiments under chloralose anesthesia in which tissue clearances of radiolabelled albumin were determined by a double isotope technique. Non‐pretreated animals served as controls. In non‐traumatized animals, pretreated rats had a higher loss of labelled albumin in calf muscle. In animals subjected to the standardized intra‐abdominal trauma, the pretreatment did not decrease the trauma‐induced loss of albumin. In neck skin, the loss of protein was higher in pretreated animals, possibly due to a decreased trauma‐induced sympathetic activation. In conclusion, degeneration of thin afferent fibers may alter the autonomic reflex response to intra‐abdominal trauma, but neuropeptide release from afferents apparently plays no role in the relocation of albumin.
Does alfentanil preserve left ventricular pump function during rapid sequence induction of anaesthesia?
Authors: Chræmmer‐Jørgensen B. , Høilund‐Carlsen P. F. , Bjerre‐Jepsen K. , Hertel S. , Marving J. , Strøm J. , Nielsen M. Damkjær , Lønborg‐Jensen H. , Jensen B. Hjort
Published: January 2009

A double‐blind, randomised trial was conducted in 24 patients without cardiopulmonary disorders (20–43 years), to assess the effect of an intravenous bolus of alfentanil on the circulatory and catecholamine responses to rapid sequence induction of general anaesthesia. Induction included injection of thiopentone 5 mg/kg and suxamethonium 1.5 mg/kg in rapid succession, followed by laryngoscopy and intubation. Half of the patients received alfentanil 100 μg/kg immediately before thiopentone. The other half received saline. Blood pressure, heart rate, and plasma catecholamine concentrations were measured repeatedly, together with left ventricular ejection fraction assessed by radionuclide angiocardiography. The responses following laryngoscopy and intubation were completely different in the saline vs. the alfentanil group: rate pressure product + 76% vs. ‐32%, mean arterial blood pressure +46% vs. ‐25%, heart +46% vs. no change, noradrenaline +117% vs. ‐25%, adrenaline +50% vs. ‐53%, and left ventricular ejection fraction ‐32% vs. no change. In conclusion, during rapid sequence induction of anaesthesia with thiopentone and suxamethonium, an intravenous bolus of alfentanil 100 μg/kg 1 min before laryngoscopy and intubation completely prevents hypertension, tachycardia, decrease in left ventricular ejection fraction, and activation of plasma catecholamines, though at the expense of moderate hypotension.
Complications and side effects during thiopentone therapy in patients with severe head injuries
Authors: Schalén W. , Messeter K. , Nordström C.‐H.
Published: January 2009

This study reports all complications and side effects occurring in 38 patients with severe traumatic brain lesions treated with barbiturate coma because of a dangerous increase in intracranial pressure. The treatment was induced by intravenous infusion of thiopentone (5–11 mg˙kg‐1) followed by a continuous infusion of 4–8 mg˙kg‐h‐1. The subsequent rate of thiopentone infusion was governed by the level of the intracranial pressure with the intention of keeping ICP below 20 mmHg (2.7 kPa). The duration of treatment was 1–15 days. Arterial hypotension occurred in 58%, hypokalemia in 82%, respiratory complications in 76%, infections in 55%, hepatic dysfunction in 87% and renal dysfunction in 47% of the patients. Twenty patients survived. Mortality in 17 patients was caused by an untreatable increase in intracranial pressure. In one patient complications due to barbiturate treatment may have contributed to the fatal outcome. In none of the other cases were the noted complications and side effects associated with any permanent symptoms or dysfunctions.