bluuebunny/crossref_metadata_2025_split huggingface dataset:
Continuous positive pressure ventilation during epidural blockade – effects on cardiac output distribution
Authors: Elowsson P. , Norlén K. , Jakobson S. 
Published: March 2003

Background: It has been shown that when cardiac output (CO) decreases during continuous positive pressure ventilation (CPPV), its regional distribution adapts with a favouring of vital organs. Does epidural blockade modify this adaptation?Methods: Regional blood flows were assessed by the microsphere technique (15 μm) in 17 anaesthetised pigs during spontaneous breathing and CPPV with 8 cm H2O end‐expiratory pressure (CPPV8) before and after epidural blockade. The block was induced at either the Th6–7 (Thep) or the L6–S1 (Lep) level with 1 ml of lidocaine 40 mg · ml−1.Results: When Lep was combined with CPPV8, mean arterial pressure and CO decreased significantly, and they decreased even more when combined with Thep. In contrast, the relative perfusion of the central nervous system, heart and kidneys remained stable during the four conditions studied. The adrenal perfusion during CPPV8 was obviated by epidural blockade. The absolute and relative perfusion of the skeletal muscle decreased during epidural blockade. The administered doses of epidural lidocaine did not affect blood flow in the spinal cord.Conclusions: The locally mediated nutritive vasoregulation of vital organs outweighed the sympathetic blockade induced by epidural blockade. During Thep blockade the animals were less capable of responding to the haemodynamic changes induced by CPPV8, probably due to the blockade of the cardiac part of the sympathetic nervous system.
Validation of a new respiratory inductive plethysmograph
Authors: Leino K. , Nunes S. , Valta P. , Takala J. 
Published: March 2003

Background: The respiratory inductive plethysmograph (RIP) can be used to monitor changes in end‐expiratory lung volume (ΔEELV), and thus, used in intensive care when evaluating positive end‐expiratory pressure (PEEP)‐induced changes in lung volumes in order to optimise the ventilator settings. We validated the newest model of RIP (Respitrace PlusTM), both under laboratory and clinical conditions, and made a comparison with a previously validated RIP (RespigraphTM) in the measurement of tidal volume (VT), long‐term EELV and PEEP‐induced acute ΔEELV.Methods: The in vitro validation was performed using a lung model and the in vivo evaluation in five spontaneously breathing normal subjects, four patients with acute lung injury (ALI) and eight anaesthetised patients.Results: The difference in VT values during PEEP manipulations between pneumotachometer (PNT) and RIP in spontaneously breathing volunteers and mechanically ventilated ALI patients was 0.1±0.9% (mean±SEM) and −5.2±0.6, respectively (effect of device NS). In anaesthetised patients, the difference between the new RIP and spirometer in the measurement of PEEP‐induced acute ΔEELV was −2.6±1.5% (PEEP‐device interaction, P<0.05). In ALI patients, the difference between PNT and RIP in the measurement of PEEP‐induced acute ΔEELV was 1.0±9.7% (NS). The new RIP had a baseline drift over 50‐fold when cold and over 10‐fold when warm compared to the old RIP in vitro.Conclusion: The new RIP is accurate enough for clinical and research purposes in the measurement of VT. Semiquantitative measurements of acute ΔEELV can be done with accuracy sufficient for clinical use, but long‐term ΔEELV monitoring is not possible. The new RIP should be kept on for several hours before measurements to minimise the drift.
Warning! Suctioning. A lung model evaluation of closed suctioning systems
Authors: Stenqvist O. , Lindgren S. , Kárason S. , Söndergaard S. , Lundin S. 
Published: March 2003

Background: Closed system suctioning, CSS, has been advocated to avoid alveolar collapse. However, ventilator manufacturers indicate that extreme negative pressure levels can be obtained during closed system suctioning, impeding the performance of the ventilator.Methods: Suctioning with a 12 or 14 Fr catheter with a vacuum level of −50 kPa was either performed with an open technology or a CSS, where the catheter is introduced through a tight‐fitting connection through the endotracheal tube, ETT. The lung model was ventilated with a Servo 900C or 300 ventilator with an I:E ratio of 1:2, 1:1 and 2:1 and extrinsic positive end‐expiratory pressure (PEEP) at 0 or 10 cm H2O. Respiratory volumes and alveolar pressure were measured at the lung model alveolus.Results: The initial suctioning flow was >40 l/min with a 14 Fr catheter. When inserting the catheter through a no. 7 ETT, PEEP rose from 11 to 23 cm H2O during volume control ventilation with an I:E ratio 1:1. During suctioning the alveolar pressure fell to 10 cm H2O below the set PEEP level. CSS during pressure control ventilation had fewer effects. Low tidal volumes, inverse I:E ratio and secretions in the tube resulted in pressures down to −92 cm H2O.Conclusion: CSS should not be used in volume control ventilation due to risk of high intrinsic PEEP levels at insertion of the catheter and extreme negative pressures during suctioning. Pressure control ventilation produces less intrinsic PEEP effect. The continuous positive airway pressure (CPAP) mode offers the least intrinsic PEEP during insertion of the catheter and least sub‐atmospheric pressure during suctioning.
Direct tracheal airway pressure measurements are essential for safe and accurate dynamic monitoring of respiratory mechanics. A laboratory study
Authors: Kárason S. , Søndergaard S. , Lundin S. , Wiklund J. , Stenqvist O. 
Published: March 2003

Background: All monitoring of respiratory mechanics should depend on tracheal pressures (Trach‐P) as endotracheal tube resistance (ETT‐Res) will otherwise distort them. The aim of this study was to investigate factors that may vary ETT‐Res, causing difficulties in ETT‐Res estimation clinically, and to evaluate a method for direct Trach‐P measurements to obviate these problems.Methods: In a model we studied: 1) The influence on ETT‐Res caused by different connectors and secretions; 2) Direct Trach‐P measurements with a catheter (o.d. 2 mm, i.d. 0.9 mm) with either end or side hole, filled with either air or liquid, introduced through the ETT lumen and evaluated regarding response time and position.Results: The pressure drop between trachea and Y‐piece increased by 15% when respectively a swivel connector and a humidification device were connected to the ETT. When injecting 1 ml and 2 ml gel into the ETT lumen the inspiratory resistance increased 100% and 600% respectively. The response time of all catheters was ≤12 ms. During constant flow in inspiratory and expiratory directions the pressure difference between an end hole catheter positioned from 2 cm above the ETT tip to 4 cm below and a reference pressure in the artificial trachea was less than 1.5 cmH2O.Conclusions: ETT connections and secretions cause a variance in resistance. Tracheal pressure can be measured with high precision with an air‐ or liquid‐filled catheter. An end hole catheter placed within 2 cm above or below the ETT tip will give sufficiently precise measurements for clinical purposes.
Transient neurologic symptoms after spinal anaesthesia using isobaric 2% mepivacaine and isobaric 2% lidocaine
Authors: Salazar F. , Bogdanovich A. , Adalia R. , Chabás E. , Gomar C. 
Published: March 2003

Background: Transient Neurological Symptoms (TNS) syndrome following subarachnoid anaesthesia was initially associated with hyperbaric lidocaine 50 mg/ml, but has also been reported with most local anaesthetics, including hyperbaric mepivacaine 40 mg/ml. The aim of this study was to determine the incidence of TNS after subarachnoid anaesthesia using isobaric mepivacaine 20 mg/ml and isobaric lidocaine 20 mg/ml.Methods: Eighty patients of both sexes, ASA class I–II, scheduled for elective minor orthopaedic surgery under subarachnoid anaesthesia, were prospectively included and randomly allocated to receive 40–60 mg of either isobaric mepivacaine 20 mg/ml (Group M) or isobaric lidocaine 20 mg/ml (Group L). Patients were evaluated on the first postoperative day by one investigator unaware of the grouping, looking for symptoms suggestive of TNS, such as pain or dysaesthesias in the buttocks or lower limbs with or without back pain.Results: TNS symptoms were observed in three patients (7.5%) of Group M and in one patient (2.5%) of Group L, without statistically significant differences between the groups. Symptoms had an abrupt onset and relief, lasted from 45 min to 24 h, and had a complete resolution without sequelae. The only statistically significant difference between groups was longer motor blockade in Group M (P=0.0031).Conclusion: In this study TNS was associated with isobaric mepivacaine 20 mg/ml, with an incidence of 7.5%, and with isobaric lidocaine 20 mg/ml, with an incidence of 2.5%, in patients having orthopaedic procedures in the supine position.
Chronic post‐sternotomy pain
Authors: Kalso E. , Mennander S. , Tasmuth T. , Nilsson E. 
Published: March 2003

Background: Chronic postoperative pain is a well‐recognised problem. The incidence of severe incapacitating pain is about 3–5% after various types of surgery such as thoracotomy, repair of inguinal hernias and mastectomy. Sternotomy causes considerable postoperative pain and patients with chronic post‐sternotomy pain are often referred to pain clinics. Epidemiological studies on chronic post‐sternotomy pain are scarce, however. The aim of this paper was to study the incidence and possible risk factors of chronic pain following sternotomy operations performed for coronary bypass grafting or thymectomy.Methods: Two groups of patients were studied for persistent pain following sternotomy operations. A questionnaire was sent in January 1997 to 71 patients with myasthenia gravis (MG) who had undergone a thymectomy during 1985–1996 and 720 patients who had had coronary bypass grafting (CABG) in 1994 were interviewed by letter. The patients were asked about the presence of pain and other symptoms in the chest, shoulders, arms or legs that they thought were connected to surgery. They were also asked about the quality of the pain and its evolvement with time. The patients’ records were checked for details about surgery, anaesthesia and the state of the coronary disease.Results: The response rate was 87%. The interval between the interview and surgery varied from 6 months to 12 years in the MG group and it was 2–3 years in the CABG group. In the MG group, 27% of the patients reported chronic post‐sternotomy pain, which was moderate to severe in 48% of the patients. In the CABG group, 28% of the patients still had post‐sternotomy pain, which was moderate to severe in 38% of patients. Of the patients who had post‐sternotomy pain, one‐third reported sleep disturbances due to the pain.Conclusion: Chronic post‐sternotomy pain is an important complication that may have a significant impact on the patient’s everyday life. Future studies will show whether minimising complications, improving postoperative care and starting early adequate pain management will reduce the incidence of this problem.
The incidence of chronic post‐sternotomy pain after cardiac surgery – a prospective study
Authors: Meyerson J. , Thelin S. , Gordh T. , Karlsten R. 
Published: March 2003

Background: Post‐sternotomy pain is sometimes a sequela of cardiac surgery. The incidence, characteristics and clinical course of post‐sternotomy pain are not well known. The aim of our study was to determine the incidence of chronic post‐sternotomy pain in patients undergoing sternotomy for cardiac surgery in general and according to the specific surgical procedure.Method: In a prospective manner, a group of 349 consecutive patients were evaluated for chronic post‐sternotomy pain one year after surgery. The patients were asked in a postal questionnaire to describe and score any persistent pain following the surgical procedure. The patients were classified into 3 sub‐groups according to surgical procedure. The first group consisted of patients operated for coronary artery by‐pass grafting (CABG) including internal thoracic artery grafting (ITAG). The second group included patients operated with CABG without ITAG and the third group of patients with valve replacement without CABG.Result: A total of 318 patients (91%) answered the questionnaire of whom 90 (28%) reported chest discomfort different from what they experienced before surgery. The scoring on the visual analogue scale (VAS, 0–100 mm) showed that 41 patients (13%) reported maximum pain intensity ≥30 mm (moderate pain), and 14 of these patients (4%) scored ≥54 mm (severe pain). There was no statistically significant difference in pain incidence and pain intensity when comparing the patients subjected to different surgical procedures.Conclusions: This prospective study shows that the overall incidence of non‐cardiac pain after sternotomy for cardiac surgery is high (28%). Most patients experience a modest pain intensity but some (1%) report severe pain, never being lower than 54 mm on VAS. The study also indicates that the incidence of pain after sternotomy is not only associated with harvest of the ITA and additional aetiological factors must be sought.
Effects of remifentanil/propofol in comparison with isoflurane on dynamic cerebrovascular autoregulation in humans
Authors: Engelhard K. , Werner C. , Möllenberg O. , Kochs E. 
Published: March 2003

Background: This study investigates the effects of remifentanil and propofol in comparison to isoflurane on dynamic cerebrovascular autoregulation in humans.Methods: In 16 awake patients dynamic cerebrovascular autoregulation was measured using transcranial Doppler sonography (TCD). Thereafter patients were intubated, ventilated with O2/air (FiO2=0.33) and randomly assigned to one of the following anesthetic protocols: group 1 (n=8): 0.5 μg · kg−1 · min−1 remifentanil combined with a propofol‐target plasma concentration of 1.5 μg · ml−1; group 2 (n=8): 1.8 % isoflurane (1.5 MAC). Following 20 min of equilibration the autoregulatory challenge was repeated. Arterial blood gases and body temperature were maintained constant over time. Statistics: Mann‐Whitney U‐test and Wilcoxon signed‐rank test.Results: Dynamic autoregulation was intact in all patients prior to induction of anesthesia expressed by an autoregulatory index (ARI) of 5.4±1.21 (mean±SD, group 1) and 5.9±0.98 (mean±SD, group 2). With remifentanil/propofol anesthesia dynamic autoregulation was similar to the awake state (group 1: ARI=4.9±0.88). In contrast, autoregulatory response was delayed with 1.5 MAC isoflurane (group 2, ARI=2.1±0.92) (P<0.05).Conclusion: These data show that dynamic cerebrovascular autoregulation is maintained with remifentanil‐based total intravenous anesthesia. This is consistent with the view that narcotics (and hypnotics) do not alter the physiologic cerebrovascular responses to changes in MAP. In contrast, 1.5 MAC isoflurane delays cerebrovascular autoregulation compared to the awake state.
Moderate hypothermia blunts the inflammatory response and reduces organ injury after acute haemorrhage
Authors: Gundersen Y. , Vaagenes P. , Pharo A. , Valø E. T. , Opstad P. K. 
Published: March 2003

Background: Reduced body temperature is a common companion to trauma/haemorrhage. Several clinical studies have identified hypothermia as an independent risk variable predisposing to increased morbidity and mortality. At the same time it is known that most enzymatic reactions are downregulated at temperatures below 37°C. Theoretically this should restrain the inflammatory response and protect the host from remote organ injury. The study was performed to test this hypothesis.Methods: Twenty‐six male Sprague Dawley rats were used for the experiments. Volume controlled haemorrhagic shock was induced by withdrawal of 2.5 ml blood/100 g body weight over 10 min. Half of the animals (n=13) were then cooled to 32.5–33°C, the other half (n=13) were kept normothermic (37.5±0.5°C). Seventy‐five minutes after initiation of bleeding, two‐thirds of the blood was retransfused. Thereafter the rats were observed for 2 h. Key substances of systemic inflammation were determined (plasma values of TNF‐α, IL‐6, IL‐10, and corticosterone; reactive oxygen species in peritoneal phagocytes), plasma markers of organ function and integrity (AST, ALT, αGST, creatinine, urea), and survival.Results: Hypothermia reduced the release of IL‐6 (P<0.01). The reductions of plasma levels of TNFα (P=0.07) and IL‐10 (P=0.09) were less clear‐cut. The release of reactive oxygen species diminished (P<0.01). Organ injury was ameliorated, as reflected by decreased levels of AST (P<0.01), αGST (P<0.01), and creatinine (P<0.01). Both groups experienced an almost identical increase of plasma corticosterone. None of the hypothermic rats died, compared to two normothermic.Conclusion: Moderate hypothermia had an organ protective effect in this model of controlled haemorrhagic shock. This coincided with a significant reduction of the proximal cytokine IL‐6 and reactive oxygen species, which conceivably influenced the outcome.
Spontaneous movements, local reactions and pain on injection of rocuronium
Authors: Mencke T. , Beerhalter U. , Fuchs‐Buder T. 
Published: March 2003

Background: We investigated the incidence of withdrawal, local reactions and pain on injection of rocuronium in 120 adult ASA I–II patients undergoing general anaesthesia (group A: 60 male patients, group B: 60 female patients).Methods: After induction of anaesthesia with propofol and remifentanil, rocuronium 0.6 mg kg−1 was injected in a separate intravenous cannula on the opposite arm. The patient’s response to the injection of rocuronium was graded using a four‐point scale. The appearance of local signs (i.e. erythema, venous sequelae) on the arm where rocuronium had been injected was recorded at the end of the injection as well as 1 h and 24 h after recovery from anaesthesia. Moreover, patients were asked 24 h after recovery from anaesthesia whether they had recall of pain or movements in this arm during induction of anaesthesia.Results: In 26 of the 120 patients (22%) included, withdrawal reactions after injection of rocuronium were observed. Of these 26 patients, 16 (13%) had severe movements. The overall incidence of withdrawal reactions after rocuronium as well as the incidence of severe reactions was significantly higher in female patients compared to male patients (overall incidence: 18 females (30%) vs. 8 males (13%), P<0.05; severe reaction: 13 females (22%) vs. 3 males (5%), P<0.05). No local reactions were observed and no patient remembered any pain or movements during induction of anaesthesia.Conclusion: The incidence and the degree of withdrawal reactions in response to the injection of rocuronium were significantly higher in women than in men. This was not associated with adverse clinical consequences for the patient’s outcome.
Assessment of the efficacy of esmolol on the haemodynamic changes induced by laryngoscopy and tracheal intubation: A meta‐analysis
Authors: Figueredo E. , Garcia‐Fuentes E. M. 
Published: March 2003

Background: Adrenergic stress response induced by laryngoscopy and tracheal intubation (LTI) appears to be attenuated by esmolol, but its potential clinical benefits have not been fully weighed against possible adverse effects.Methods: A systematic search up to May 2000 was performed using MEDLINE, EMBASE, LILACS, Cochrane library, manual searching and bibliographies in all languages. All randomised comparisons of esmolol with placebo on the haemodynamic changes elicited by LTI were obtained. Trials were included in the present meta‐analysis if they recorded heart rate (HR), systolic pressure (SBP), mean arterial pressure (MAP) or diastolic pressure (DBP) at three different stages: pre‐induction, immediately prior to intubation, and in the post‐intubation period. Weighted mean differences (WMD) and 95% confidence intervals (CI) of the changes in the haemodynamic variables between treatment and placebo groups were calculated.Results: Of 72 publications identified, 38 randomised controlled trials containing a total of 2009 patients were finally included. Eleven different regimens and doses of esmolol demonstrated effectiveness in the attenuation of HR and BP after LTI in a dose‐dependent manner. The most effective regimen was a loading dose of 500 μg · kg−1 · min−1 over 4 min followed by continuous infusion dose of 200–300 μg · kg−1 · min−1[WMD: 20.2 bpm (95% CI: 15.6 to 24.7)]. High bolus dose (200 mg) of esmolol produced a considerable decrease in DBP [WMD 10.1 mmHg (95% CI: 7.3 to 12.8)].Conclusion: Esmolol is effective, in a dose‐dependent manner, in the attenuation of the adrenergic response to LTI. To minimise its adverse effects it should be administered, when considered clinically appropriate, as a continuous infusion regimen.
Airway management behaviour, experience and knowledge among Danish anaesthesiologists – room for improvement
Authors: Kristensen M. S. , Møller J. 
Published: March 2003

Background: Problems with managing the airways in relation to anaesthesia causes severe morbidity and mortality. A large proportion of these adverse respiratory events is preventable. Still patients continue to die from airway disasters related to anaesthesia, also in Scandinavia. The goal of this study is to identify which efforts are likely to improve this situation.Methods: A questionnaire asking about experience, behaviour and availability of various items of equipment was mailed to all members of the Danish Society of Anaesthesiologists and were returned anonymously.Results: More than 65% of respondents have sufficient access to a flexible fibrescope, but still 17% of specialists have no access and the vast majority (>67%) has little (1–10 times) or no experience in its use for awake intubation. A total of 52–70% knew the basic principles of the ASA difficult airway algorithm, but despite this only 25–50% would perform awake intubation if a difficult intubation was expected. More than 20% of respondents had experienced preventable airway management mishaps. In all, 18–46% did not know how to oxygenate via the cricothyroid membrane.Conclusion: There is room for improvement regarding airway management skills among Danish anaesthesiologists. It is likely that airway management can be improved by: A) Better knowledge of an appropriate plan, algorithm, for airway management. B) Awake intubation used more often. C) More experience in fibreoptic intubation. D) All anaesthesiologists accepting that previous difficult intubation is an indicator of future difficulties. E) All anaesthesiologists knowing, and practising on manikins, how to oxygenate via the cricothyroid membrane. F) Always having a laryngeal mask airway immediately available when inducing anaesthesia.
Comparison of plasma α glutathione S‐transferase concentrations during and after low‐flow sevoflurane or isoflurane anaesthesia
Authors: Higuchi H. , Adachi Y. , Wada H. , Kanno M. , Satoh T. 
Published: March 2003

Background: We evaluated the effect of low‐flow sevoflurane anaesthesia, in which compound A is generated, and isoflurane anaesthesia, in which compound A is not generated (n=13 in each group), on hepatocellular integrity using α glutathione S‐transferase (GST). α GST is a more sensitive and specific marker of hepatocellular damage than is aminotransferase activity and correlates better with hepatic histology.Methods: Sevoflurane or isoflurane were delivered without nitrous oxide with a fresh gas flow of 1 l/min. Concentrations of compound A in the circuit were measured hourly, and plasma α GST concentrations were measured perioperatively.Results: Mean duration of anaesthesia was 338±92 min in the sevoflurane group and 320±63 min in the isoflurane group. Mean compound A concentration in the sevoflurane group was 28.6±9.0 ppm. There was no significant difference in α GST concentrations between the sevoflurane and isoflurane groups during or after anaesthesia.Conclusion: These results indicate that low‐flow sevoflurane and isoflurane anaesthesia have the same effect on hepatic function, as assessed by plasma α GST concentrations.