bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preoperative predictors of moderate to intense acute postoperative pain in patients undergoing abdominal surgery
Authors: Caumo W. , Schmidt A. P. , Schneider C. N. , Bergmann J. , Iwamoto C. W. , Adamatti L. C. , Bandeira D. , Ferreira M. B. C. 
Published: March 2003

Background:  Pain is a sensory and emotional experience that is influenced by physiologic, sensory, affective, cognitive, socio‐cultural, and behavioral factors. Consistent with the perspective to improve the postoperative pain control, the present study has the purpose of assessing the effect of presurgical clinical factors, psychological and demographic characteristics as predictors for reporting moderate to intense acute postoperative pain.Methods:A prospective cohort study was performed with 346 inpatients undergoing abdominal elective surgery (ASA physical status I‐III, age range 18–60 years). The measuring instruments were Pain Visual Analog Scale, the State‐Trait Anxiety Inventory, and the Montgomery‐Åsberg Depression Rating Scale. Multivariate conditional regression modeling was used to determine independent predictors for moderate to intense acute postoperative pain.Results:  Moderate to intense acute postoperative pain was associated with status ASA III (odds ratio (OR) = 1.99), age (OR = 4.72), preoperative moderate to intense pain (OR = 2.96), chronic pain (OR = 1.75), high trait‐anxiety and depressive mood moderate to intense (OR = 1.74 and OR = 2.00, respectively). Patients undergoing surgery to treat cancer presented lower risk for reporting moderate to intense pain OR = 0.39, as well as those that received the epidural analgesia and multimodal analgesia with systemic opioid (OR = 0.09 and OR = 0.16, respectively).Conclusions:The identification of predictive factors for intense acute postoperative pain may be useful for designing specific preventive interventions to relieve patient suffering. Especially because few of these variables are accessible for medical intervention, which would improve the clinical outcomes and quality of life of patients at risk of moderate to intense acute postoperative pain.
Victims of awareness
Authors: Lennmarken C. , Bildfors K. , Enlund G. , Samuelsson P. , Sandin R. 
Published: March 2003

Background: Intraoperative awareness with explicit recall may be followed by long‐lasting mental symptoms. However, the average risk for developing mental sequelae after awareness, and the average severity and the duration of symptoms has not previously been illustrated in a consecutive series of awareness cases.Methods: Nine patients among 18 consecutive, prospectively identified cases of intraoperative awareness with recall could be located after approximately 2 years and agreed to an interview about possible persisting problems.Results: Four of the nine interviewed patients were still severely disabled due to psychiatric/psychological sequelae. All of these patients had experienced anxiety during the period of awareness, but only one had complained about pain. Another three patients had less severe, transient mental symptoms, although they could cope with these in daily life. Two patients denied any sequelae from their awareness episode.Conclusions: Up to 3 weeks after their unsuccessful anesthetic, repeated information and discussions had been offered. Despite the fact that all patients at that time claimed to be satisfied with this management, and eventually considered no further contacts necessary, this was obviously inaccurate. Therefore, professional psychiatric assessment, treatment and long‐term follow‐up should constitute standard practice for all patients who have experienced intraoperative awareness.
Comparison of auditory evoked potentials and the A‐line ARX Index for monitoring the hypnotic level during sevoflurane and propofol induction
Authors: Litvan H. , Jensen E. W. , Revuelta M. , Henneberg S. W. , Paniagua P. , Campos J. M. , Martínez P. , Caminal P. , Villar Landeira J. M. 
Published: March 2003

Background: Extraction of the middle latency auditory evoked potentials (AEP) by an auto regressive model with exogenous input (ARX) enables extraction of the AEP within 1.7 s. In this way, the depth of hypnosis can be monitored at almost real‐time. However, the identification and the interpretation of the appropriate signals of the AEP could be difficult to perform during the anesthesia procedure. This problem was addressed by defining an index which reflected the peak amplitudes and latencies of the AEP, developed to improve the clinical interpretation of the AEP. This index was defined as the A‐line Arx Index (AAI).Methods: The AEP and AAI were compared with the Modified Observers Assessment of Alertness and Sedation Scale (MOAAS) in 24 patients scheduled for cardiac surgery, anesthetized with propofol or sevoflurane.Results: When comparing the AEP peak latencies and amplitudes and the AAI, measured at MOAAS level 5 and level 1, significant differences were achieved. (mean(SD) Nb latency: MOAAS 5 51.1 (7.3) ms vs. MOAAS 1: 68.6 (8.1) ms; AAI: MOAAS 5 74.9 (13.3) vs. MOAAS 1 20.7 (4.7)). Among the recorded parameters, the AAI was the best predictor of the awake/anesthetized states.Conclusion: We conclude that both the AAI values and the AEP peak latencies and amplitudes correlated well with the MOAAS levels 5 (awake) and 1 (anesthetized).
Ropivacaine 2 mg/mL vs. bupivacaine 1.25 mg/mL with sufentanil using patient‐controlled epidural analgesia in labour
Authors: Hofmann‐Kiefer K. , Saran K. , Brederode A. , Bernasconi H. , Zwissler B. , Schwender D. 
Published: March 2003

Background: In recent studies, minimum local analgesic concentrations have been defined as 0.93 mg/mL for bupivacaine and 1.56 mg/mL for ropivacaine for epidural analgesia for the first stage of labour, resulting in an analgesic potency ratio of 1 : 0.6. In the current study we compared ropivacaine and bupivacaine in a PCEA system (combined with sufentanil) taking this potency ratio into account but administering drug doses providing sufficient analgesia for all stages of labour.Methods: In a prospective, double‐blinded study 114 parturients were randomised to receive either ropivacaine 2 mg/mL with sufentanil 0.75 µg/mL or bupivacaine 1.25 mg/with sufentanil 0.75 µg/mL. After epidural catheter placement, PCEA was available with boluses of 4 mL, a lock‐out time of 20 min and no basal infusion rate. We evaluated pain intensity during contractions, sensory and motor function, duration of labour, mode of delivery and neonatal outcome. Consumption of local anaesthetic and opioid drugs and PCEA system variables were recorded.Results: Mean total consumption as well as mean hourly drug consumption was significantly increased in the ropivacaine–sufentanil group. No differences in analgesic quality, sensory or motor blocking potencies or neonatal outcome variables between groups were detected. Frequency of instrumental deliveries was significantly increased in the ropivacaine–sufentanil group.Conclusions: The results support the findings of previously published studies postulating ropivacaine to be 40–50% less potent for labour epidural analgesia compared to bupivacaine. However, we observed an increased frequency of instrumental deliveries with ropivacaine. To evaluate the clinical relevance of these findings, further investigations are warranted.
The difference between sleep and anaesthesia is in the intracellular signal: propofol and GABA use different subtypes of the GABAA receptor β subunit and vary in their interaction with actin
Authors: Björnström K. , Eintrei C. 
Published: March 2003

Background: Propofol is known to interact with the γ‐aminobutyric acidA (GABAA) receptor, however, activating the receptor alone is not sufficient for producing anaesthesia.Methods: To compare propofol and GABA, their interaction with the GABAA receptor β subunit and actin were studied in three cellular fractions of cultured rat neurons using Western blot technique.Results: Propofol tyrosine phosphorylated the GABAA receptor β2 (MW 54 and 56 kDa) and β3 (MW 57 kDa) subtypes. The increase was shown in both the cytoskeleton (β2(54) and β2(56) subtypes) and the cell membrane (β2(54) and β3 subtypes). Concurrently the 56 kDa β2 subtype was reduced in the cytosol. Propofol, but not GABA, also tyrosine phosphorylated actin in the cell membrane and cytoskeletal fraction. Without extracellular calcium available, the amount of actin decreased in the cytoskeleton, but tyrosine phosphorylation was unchanged. GABA caused increased tyrosine phosphorylation of β2(56) and β3 subtypes in the membrane and both β2 subtypes in the cytoskeleton but no cytosolic tyrosine phosphorylation.Conclusion: The difference between propofol and GABA at the GABAA receptor was shown to take place in the membrane, where the β2(54) was increased by propofol and instead the β2(56) subtype was increased by GABA. Only propofol also tyrosine phosphorylated actin in the cell membrane and cytoskeletal fraction. This interaction between the GABAA receptor and actin might explain the difference between anaesthesia and physiological neuronal inhibition.
No influence of the endothelin receptor antagonist bosentan on basal and indomethacin‐induced reduction of cerebral blood flow in pigs
Authors: Rasmussen M. , Poulsen P. H. , Treiber A. , Delahaye S. , Tankisi A. , Cold G. E. , Therkelsen K. , Gjedde A. , Astrup J. 
Published: March 2003

Background: The mechanism behind indomethacin‐induced cerebral vasoconstriction is incompletely understood. We tested the hypothesis that the mixed endothelin‐1 receptor antagonist bosentan would modify or prevent indomethacin‐induced reduction of CBF in the anaesthetized pig. Furthermore, we investigated the effect of bosentan on resting CBF and CMRO2.Methods: Twelve pigs were randomized in two groups of six, and received either bosentan and indomethacin (group 1), or placebo and indomethacin (group 2). Anaesthesia was induced with ketamine and midazolam and maintained with fentanyl, nitrous oxide and pancuronium. Baseline measurements of CBF and CMRO2 were performed before intravenous bolus injection of bosentan (10 mg/kg) or placebo (0.9% NaCl). The second CBF and CMRO2 measurement was performed 30 min after administration of bosentan/placebo. A 40‐min infusion of indomethacin (0.05 mg/kg/min) was administered and the third CBF and CMRO2 measurement was performed 80 min after administration of bosentan/placebo. Independently, pharmacokinetic data of bosentan were generated in four pigs.Results: In group 1, baseline CBF was 55 ± 7 ml/100 cm3/min. Administration of bosentan i.v. did not change CBF significantly. Indomethacin decreased CBF to 41 ± 5 ml/100 cm3/min (P < 0.002). In group 2, baseline CBF was 54 ± 10 ml/100 cm3/min. Placebo did not change CBF while indomethacin decreased CBF significantly to 41 ± 5 ml/100 cm3/min (P < 0.002). No significant changes in CMRO2 were observed. In group 2, a significant increase in MABP was observed after administration of indomethacin. No change in MABP was observed in the bosentan‐treated animals. Total plasma concentrations of bosentan at the time of the first and the second PET measurement were 3.9 and 1.4 µg/ml, respectively. The corresponding values for the pharmacologically active metabolite Ro 48–5033 were 1.2 and 0.4 µg/ml.Conclusion: These findings indicate that endothelin receptor stimulation is not involved in indomethacin‐induced cerebral vasoconstriction or maintenance of cerebrovascular tone in the anaesthetized pig. However, our results suggest that the increase in MABP is mediated through endothelin receptors.
Death after injury in rural Norway: high rate of mortality and prehospital death
Authors: Wisborg T. , Høylo T. , Siem G. 
Published: March 2003

Background: Finnmark is a rural and remote area in Norway with a sparse population and long distances. Trauma‐related mortality has been consistently above the Norwegian national average for the last 20 years. Although the causes of death are well established, very little is known about the time and place of death. This information has implications for the organization of emergency services in rural areas. We examined all trauma deaths over a five‐year period in order to inform the debate on how best to reduce our above‐average mortality rate.Methods: A retrospective study of all deaths after trauma (ICD‐9 E800‐E999) during the years 1991–95 using data obtained from the National Registry of Death.Results: Of the 183 cases found, 130 deaths were due to trauma using definitions comparable to similar studies. The mortality rate was 77 per 100 000 inhabitants per year. Death occurred in the prehospital phase in 85% of cases. Seventy‐two per cent of all deaths (regardless of location) occurred within the first h after injury, eight per cent from 1 to 4 h and the remaining 20% occurred after 4 h.Conclusion: When planning interventions to reduce the mortality rate from trauma in rural areas, a high proportion of prehospital deaths should be expected. The high number of patients who are found dead (which can only be reduced by injury prevention) must be taken into account. Measures to reduce ‘preventable’ causes of death by bystanders should be evaluated. Further knowledge of exact mechanisms of death in the prehospital phase is required.
Effects of preoperative oral carbohydrates and peptides on postoperative endocrine response, mobilization, nutrition and muscle function in abdominal surgery
Authors: Henriksen M. G. , Hessov I. , Dela F. , Vind Hansen H. , Haraldsted V. , Rodt S. Å. 
Published: March 2003

Background: Surgery is succeeded by long‐lasting state of relative peripheral insulin resistance, which is reduced by giving glucose infusion or oral carbohydrate‐rich drinks immediate before operating instead of fasting. The aim of the present study was to investigate whether oral carbohydrate or carbohydrate with peptide drinks preoperatively instead of fasting would improve postoperative voluntary muscle strength, nutritional intake and ambulation, decrease postoperative fatigue, anxiety and discomfort, and reduce the endocrine response to surgery.Methods: Forty‐eight patients were included and randomized into three groups to receive 2 × 400 ml of carbohydrate‐rich drinks or to fast overnight and allowed only water. Voluntary grip and quadriceps strength, body composition, pulmonary function, VAS‐score of eight parameters of wellbeing, muscle biopsies and insulin, glucagon, IGF‐1 and free fatty acids were measured before and after the operation. The basic postoperative regimen for all groups were immediate oral nutrition and early enforced mobilization.Results: Significant postoperative decrease in glycogen synthase activity in the muscle biopsies was reduced in the intervention groups, and in combination, the intervention groups had a less reduced quadriceps strength after one week (−10% vs. −16%, NS) and one month (−5% vs. −13%, P < 0.05). Minor changes in the endocrine response to surgery were found without differences between the groups, and there were no differences between the groups in ambulation time, nutritional intake or subjective measures of wellbeing.
Preoperative blood pressure and catecholamines related to hypothermia during general anesthesia
Authors: Kasai T. , Hirose M. , Matsukawa T. , Takamata A. , Yaegashi K. , Tanaka Y. 
Published: March 2003

Background: We previously demonstrated that preoperative blood pressure values affect intraoperative hypothermia during general anesthesia. We hypothesized that increased catecholamine secretion could be responsible for the relationship between preoperative blood pressure and hypothermia.Methods: To evaluate the effect of preoperative systolic blood pressure (SBP) and plasma catecholamine levels on core temperature during general anesthesia, 40 male patients who were scheduled for open abdominal surgery were allocated to two groups: those whose preoperative SBP was 140 mmHg or greater (high SBP group, n = 20), and those whose SBP was less than 140 mmHg (normal SBP group, n = 20). Anesthesia was maintained with 0.4% isoflurane and opioids.Results: The average age, height, and weight of the patients in the two groups did not differ. Preoperative SBP, mean blood pressure, diastolic blood pressure and heart rate in the high SBP group were significantly higher than those in the normal SBP group. Plasma norepinephrine concentrations in the high SBP group were significantly greater than those in the normal SBP group before and 1 h after the induction of anesthesia. Tympanic membrane temperatures in the normal SBP group started to decline further just after the induction of anesthesia, more so than that in the high SBP group. The vasoconstriction threshold in the normal SBP group was significantly lower than that in the high SBP group.Conclusion: These results suggest that the higher levels of preoperative catecholamine secretion contributed to the lesser degree of intraoperative hypothermia observed in the high SBP group.
New mathematical model for the correct prediction of the exchangeable blood volume during acute normovolemic hemodilution
Authors: Meier J. , Kleen M. , Habler O. , Kemming G. , Messmer K. 
Published: March 2003

Background: The blood volume that has to be exchanged for crystalloids and/or colloids during acute normovolemic hemodilution (ANH) in order to reach a preset target hemoglobin concentration (hb) is usually predicted by the Bourke and Smith formula developed in 1974. This formula systematically overestimates the ‘true’ exchangeable blood volume (EBV), a fact that may potentially endanger patients because the target hb will be missed and the normovolemic anemia might turn out to be more severe than a priori intended. Our objective was to develop a more accurate mathematical model of hemodilution kinetics and to validate this new model in animals and in patients undergoing ANH.Methods: Twenty‐two anesthetized beagle dogs and 18 patients under balanced anesthesia underwent isovolemic hemodilution with hydroxyethyl starch (HAES 6%, 200 000) to a target hb of 7 g dl−1 or 9 g dl−1, respectively. Exchangeable blood volume predicted by use of the different mathematical models was compared with the blood volume actually exchanged to meet the preset target hb.Results: Calculation of EBV by the Bourke and Smith formula (EBVB + S) systematically overestimated the volume actually exchanged (overestimation: dogs 15%, patients 20%), whereas our new iterative model predicted EBV (EBViterative) more reliably (overestimation: dogs 1%, patients 8%). In both cases EBVB + S differed significantly from the EBViterative.Conclusion: Exchangeable blood volume is predicted more accurately by the new iterative model than by the Bourke and Smith formula. The iterative model leads to an improvement in patient safety and provides a physiologically adequate basis for future studies investigating the efficacy of ANH in reducing allogenic blood transfusions.
Effects of acute normovolemic hemodilution on ventriculoarterial coupling in dogs
Authors: Nozaki J. , Kitahata H. , Tanaka K. , Kawahito S. , Oshita S. 
Published: March 2003

Background: Acute normovolemic hemodilution (ANH) causes a decrease in systemic vascular resistance. Similar to vasodilating drugs, ANH might modify ventriculoarterial coupling. Left ventricular elastance (Ees), effective arterial elastance (Ea), stroke work (SW), and pressure volume area (PVA) were used as indicators to examine the effects of ANH on this coupling.Methods: After institutional approval eight dogs were anesthetized with isoflurane and subjected to measurements including aortic pressure, left ventricular (LV) pressure, and LV volume. Left ventricular volume was measured with a conductance catheter. Ees was determined as the slope of the end‐systolic pressure‐volume relationship. Ea was determined as the ratio of LV end‐systolic pressure to stroke volume. Ventriculoarterial coupling was evaluated as the ratio of Ees to Ea. Mechanical efficiency, another criterion for ventriculoarterial coupling, was calculated as the ratio of SW to PVA. Data are expressed as mean±SD, and P<0.05 was considered significant.Results: Normovolemic exchange of 50 ml kg−1 of blood for 6% hydroxyethyl starch (ANH50) reduced hemoglobin concentration from 12.8±3.0 g dl−1 to 6.4±1.3 g dl−1. Acute normovolemic hemodilution 50 did not change Ees significantly although it significantly decreased Ea. Left ventricular elastance/Ea did not change after ANH (1.0±0.4 at baseline and 1.2±0.5 at ANH50). Acute normovolemic hemodilution 50 significantly increased SW and PVA, preventing SW/PVA from changing significantly after ANH (0.57±0.10 at baseline and 0.62±0.14 at ANH50).Conclusion: Before ANH, ventriculoarterial coupling was so matched as to maximize SW at the expense of the work efficiency. This relation was preserved at ANH50.
Remifentanil produces vasorelaxation in isolated rat thoracic aorta strips
Authors: ÜNlügenç H. , Itegin M. , ÖCal I. , ÖZalevli M. , Güler T. , Isik G. 
Published: March 2003

Background: Remifentanil can cause transient instability in hemodynamic variables. However this change may not be solely the result of autonomic or central nervous system inhibition or of centrally mediated vagal stimulation. In this study, the aim was to examine the direct effects of remifentanil on isolated thoracic aorta strips in vitro.Methods: Forty‐five Wistar rat thoracic aorta rings were isolated, and contraction–relaxation responses were recorded.Results: In aortic rings precontracted with phenylephrine or potassium chloride, remifentanil produced concentration‐dependent relaxation in both endothelium‐intact and denuded rings (P<0.001). Remifentanil induced significantly greater relaxation in intact rings than in those denuded of endothelium, regardless of whether they were precontracted with phenylephrine hydrochloride or KCl (P<0.001). When the endothelium was present, remifentanil produced greater relaxation in KCl‐contracted rings than in PE‐contracted rings at lower concentrations (10−9 and 10−8), and similar relaxation at higher concentrations (10−7 and 10−6). However, when the endothelium was removed, relaxation was similar in both solutions, at all concentrations (10−9 to 10−6). In intact rings, pretreatment with L‐NO‐ARG or indomethacin reduced the degree of remifentanil‐induced relaxation. In Ca+ ± free media, calcium‐dependent KCl contractions were inhibited in a dose‐dependent manner by remifentanil (P<0.001).Conclusion: Remifentanil vasodilates by an endothelium‐dependent mechanism, involving prostacyclin and nitric oxide released from the endothelium. Its endothelium‐independent vasodilation probably occurs via the suppression of voltage‐sensitive Ca++ channels.