bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of lung recruitment maneuver and positiveend‐expiratory pressure on lung volume, respiratory mechanics and alveolar gas mixing in patients ventilated after cardiac surgery
Authors: Dyhr T. , Laursen N. , Larsson A. 
Published: March 2003

Background: It is unclear whether positive end‐expiratory pressure (PEEP) is needed to maintain the improved oxygenation and lung volume achieved after a lung recruitment maneuver in patients ventilated after cardiac surgery performed in the cardiopulmonary bypass (CPB).Methods: A prospective, randomized, controlled study in a university hospital intensive care unit. Sixteen patients who had undergone cardiac surgery in CPB were studied during the recovery phase while still being mechanically ventilated with an inspired fraction of oxygen (FiO2) 1.0. Eight patients were randomized to lung recruitment (two 20‐s inflations to 45 cmH2O), after which PEEP was set and kept for 2.5 h at 1 cmH2O above the pressure at the lower inflexion point (14±3 cmH2O, mean ±SD) obtained from a static pressure‐volume (PV) curve (PEEP group). The remaining eight patients were randomized to a recruitment maneuver only (ZEEP group). End‐expiratory lung volume (EELV), series dead space, ventilation homogeneity, hemodynamics and PaO2 (oxygenation) were measured every 30 min during a 3‐h period. PV curves were obtained at baseline, after 2.5 h, and in the PEEP group at 3 h.Results: In the ZEEP group all measures were unchanged. In the PEEP group the EELV increased with 1220±254 ml (P<0.001) and PaO2 with 16±16 kPa (P<0.05) after lung recruitment. When PEEP was discontinued EELV decreased but PaO2 was maintained. The PV curve at 2.5 h coincided with the curve obtained at 3 h, and both curves were both steeper than and located above the baseline curve.Conclusions:  Positive end‐expiratory pressure is required after a lung recruitment maneuver in patients ventilated with high FiO2 after cardiac surgery to maintain lung volumes and the improved oxygenation.
Intensive care unit syndrome/delirium is associated with anemia, drug therapy and duration of ventilation treatment
Authors: Granberg Axèll A. I. R. , Malmros C. W. , Bergbom I. L. , Lundberg D. B. A. 
Published: March 2003

Background:  We have performed a prospective qualitative investigation of the ICU syndrome/delirium; the main parts of which have recently been published. The aim of the present study was to explore the relationship between the ICU syndrome/delirium and age, gender, length of ventilator treatment, length of stay and severity of disease, as well as factors related to arterial oxygenation and the amount of drugs used for sedation/analgesia.Methods:  Nineteen mechanically ventilated patients who had stayed in the ICU for more than 36 h were closely observed during their stay, and interviewed in depth twice after discharge. Demographic, administrative and medical data were collected as a part of the observation study.Results:   Patients with severe delirium had significantly lower hemoglobin concentrations than those with moderate or no delirium (P=0.033). Patients suffering from severe delirium spent significantly longer time on the ventilator and at the ICU, and were treated with significantly higher daily doses of both fentanyl (P=0.011) and midazolam (P=0.011) in comparison with those reporting only moderate or no symptoms of delirium. There were no significant differences in the Therapeutic Intervention Scoring System scores, reflecting the degree of illness, between patients with and without delirium.Conclusion:  The development of the ICU syndrome/delirium seems to be associated with decreased hemoglobin concentrations and extended times on the ventilator. Prolonged ICU stays and treatment with higher doses of sedatives and opioids in patients with delirium appear to be secondary phenomena rather than causes.
Monitoring functional residual capacity (FRC) by quantifying oxygen/carbon dioxide fluxes during a short apnea
Authors: Stenqvist O. , Olegård C. , Søndergaard S. , Odenstedt H. , Kárason S. , Lundin S. 
Published: March 2003

Background: Clinically applicable methods for measuring FRC are currently lacking. This study presents a new method for FRC monitoring based on quantification of metabolic gas fluxes of O2 and CO2 during a short apnea.Methods: Base line exchange of oxygen and carbon dioxide was measured with indirect calorimetry. End‐tidal (∼alveolar) O2 and CO2 concentrations were measured before and after a short apnea, 8–12 s, and FRC was calculated according to standard washin/washout formulas taking into account the increased solubility of CO2 in blood when the tension is increased during the apnea. The method was tested in a lung model with CO2 excretion and O2 consumption achieved by combustion of hydrogen and implemented in six ventilator‐treated patients with acute respiratory failure (ARF).Results: In the lung model the method showed excellent correlation (r = 0.98) with minimal bias (34 ml) and a good precision, limits of agreement being 160 and ‐230 ml, respectively, compared to the reference method. In six ARF patients changes in FRC induced by increase or decrease in PEEP and measured with the O2/CO2 flux FRC method corresponded well with changes in reference values of FRC (r = 0.76–0.94).Conclusions: A new method has been proposed in which FRC could be monitored from measurements of physiological fluxes of gases during a short apnea with the use of standard ICU equipment and some calculations. We anticipate that with further development, this technique could provide a new tool for monitoring respiratory changes and ventilator management in the ICU.
Nasal administration of opioids for pain management in adults
Authors: Dale O. , Hjortkjær R. , Kharasch E. D. 
Published: March 2003

Background: Nasal administration of opioids may be an alternative route to intravenous, subcutaneous, oral transmucosal, oral or rectal administration in some patients. Key features may be self‐administration, combined with rapid onset of action. The aim of this paper is to evaluate the present base of knowledge on this topic.Methods: The review is based on human studies found in Medline or in the reference list of these papers. The physiology of the nasal mucosa and some pharmaceutical aspects of nasal administration are described. The design of each study is described, but not systematically evaluated.Results: Pharmacokinetic studies in volunteers are reported for fentanyl, alfentanil, sufentanil, butorphanol, oxycodone and buprenorphine. Mean times for achieving maximum serum concentrations vary from 5 to 50 min, while mean figures for bioavailability vary from 46 to 71%. Fentanyl, pethidine and butorphanol have been studied for postoperative pain. Mean onset times vary from 12 to 22 min and times to peak effect from 24 to 60 min. There is considerable interindividual variation in pharmacokinetics and clinical outcome. This may partly be due to lack of optimization of nasal formulations. Patient‐controlled nasal analgesia is an effective alternative to intravenous PCA. Adverse effects are mainly those related to the opioids themselves, rather than to nasal administration. Some experience with nasal opioids in outpatients and for chronic pain has also been reported.Conclusion: Nasal administration of opioids has promising features, but is still in its infancy. Adequately designed clinical studies are needed. Improvements of nasal sprayer devices and opioid formulations may improve clinical outcome.
Prehospital advanced life support provided by specially trained physicians: is there a benefit in terms of life years gained?
Authors: Lossius H. M. , Søreide E. , Hotvedt R. , Hapnes S. A. , Eielsen O. V. , Førde O. H. , Steen P. A. 
Published: March 2003

Background:  The benefit of prehospital advanced life support (ALS) is disputed, as is the prehospital use of specially trained, hospital‐based physicians. The purpose of the study was to assess the health benefit from an anesthesiologist‐manned prehospital emergency medical service (EMS), and to separate the benefit of the anesthesiologist from that of rapid transport.Methods:  The anesthesiologist‐manned helicopter and rapid response car service at Rogaland Central Hospital assisted 1106 patients at the scene during the 18‐month study period. Two expert panels assessed patients with a potential health benefit for life years gained (LYG) using a modified Delphi technique. The probability of survival as a result of the studied EMS was multiplied by the life expectancy of each patient. The benefit was attributed either to the anesthesiologist, the rapid transport or a combination of both.Results:  The expert panels estimated a benefit of 504 LYG in 74 patients (7% of the total study population), with a median age of 54 years (range 0–88). The cause of the emergency was cardiac diseases (including cardiac arrest) in 61% of the 74 patients, trauma in 19%, and cardio‐respiratory failure as a result of other conditions in 20%. The LYG were equally divided between air and ground missions, and the majority (88%) were attributed solely to ALS by the anesthesiologist.Conclusion:  The expert panels found LYG in every 14th patient assisted by this anesthesiologist‐manned prehospital EMS. There was no difference in LYG between the helicopter and the rapid response car missions. The role of the anesthesiologist was crucial for health benefits.
Paramedic helicopter emergency service in rural Finland – do benefits justify the cost?
Authors: Kurola J. , Wangel M. , Uusaro A. , Ruokonen E. 
Published: March 2003

Background: The benefit of the Helicopter Emergency Medical Service (HEMS) is not well documented. The aim of our study was to investigate the potential health benefits of HEMS, and their relation to cost of the service in a rural area in Finland. We also evaluated whether the patient benefit is due to early Advanced Life Support (ALS) procedures performed on‐scene, or due to rapid transport of patients to definitive care.Methods: We reviewed all helicopter missions during 1 year (1999). Based on given prehospital care, we divided these missions into various categories. At the time of discharge, in‐hospital records were reviewed for patients who received prehospital ALS care in order to estimate the potential benefit of HEMS.Results: There were 588 missions. In 40% (n = 233/588), the mission was aborted. ALS care was given on‐scene to 206 patients. It was estimated that in this group lives of three patients (1.5%) were saved, and 42 (20%) patients, mostly with cardiovascular disease, otherwise benefited from the service. The majority (84%) of the patients benefited from on‐scene ALS procedures only. The cost for beneficial mission was €28 444.Conclusion: A minority of all patients did benefit from HEMS. Benefit was related to early ALS care and the cost per beneficial mission was 28 444.
Epidural blood patch for management of postdural puncture headache in adolescents
Authors: Ylönen P. , Kokki H. 
Published: March 2003

Background: In some patients spinal puncture (SP) is followed by postdural puncture headache (PDPH). When the symptoms of PDPH are severe and are not relieved within a few days an epidural blood patch (EBP) might be performed. The aim of this survey was to review requests for EBPs and to evaluate the effectiveness of EBP in patients aged 13–18 years during a 6.5 year period ending in June 2001.Methods: The Information System Patient Measures Database was interrogated to identify patients who were referred for EBP. After identification, the patients' medical records were reviewed in detail for the characteristics of PDPH and other symptoms, and for the effectiveness of the EBP.Results: Forty‐two EBPs were performed after 40 SPs on 37 patients (24 girls, 13 boys). Epidural blood patches were performed twice in five patients. The reasons for repeating the procedure were repeat SP with new PDPH in three patients and an unsatisfactory effect in two patients. Twenty‐eight of the 40 spinal punctures (70%) had been performed for diagnostic use and 10 (25%) for spinal anesthesia. Two patients (5%) developed PDPH after inadvertent dural puncture with an epidural needle. In 37 cases the criteria for PDPH were fulfilled, and one patient had a cerebrospinal fluid fistula headache. Two‐thirds of the girls had associated symptoms of headache compared with one‐third of the boys. Epidural blood patch was performed 1–22 days after SP with 0.2 ml/kg (mean) of autologous blood injected into the epidural space. The success rate of the first injection was 37 out of 40 EBP (93%), and the second injection was effective in both patients with recurred PDPH.Conclusion: Epidural blood patch seems to be an effective and safe procedure in adolescents for treating severe and persistent PDPH.
Postoperative pain relief following intrathecal bupivacaine combined with intrathecal or oral clonidine
Authors: Dobrydnjov I. , Axelsson K. , Samarütel J. , Holmström B. 
Published: March 2003

Background: The purpose of the present study was to evaluate the postoperative analgesic and adverse effects of equal doses of oral or intrathecal clonidine in spinal anaesthesia with bupivacaine plain.Methods: Forty‐five ASA I‐III orthopaedic patients scheduled for osteosynthesis of a traumatic femur fracture were randomised in a double‐blind fashion to one of 3 groups. Patients received 15 mg of plain bupivacaine intrathecally (group B) or an intrathecal mixture of bupivacaine 15 mg and clonidine 150 mg (group CIT). In group CPO oral clonidine 150 mg was administered 60 min before intrathecal injection of bupivacaine 15 mg.Results: Oral and intrathecal clonidine prolonged the time until the first request for analgesics, 313 ± 29 and 337 ± 29 min, respectively, vs. 236 ± 27 min in group B (P < 0.01). The total 24‐ h PCA morphine dose was significantly lower in group CIT(19.3 ± 1.3 mg) compared to groups B and CPO(33.4 ± 2.0 and 31.2 ± 3.1 mg). MAP was decreased significantly during the first hour after intrathecal clonidine(14%) and during the first 5 h after oral clonidine(14–19%). HR decreased in CIT during the 5th and 6th postoperative hours(7–9%) and during the first 2 h(9%) in CPO (P < 0.01). The degree of sedation was more pronounced in group CPO during the first 3 h. Four patients had pruritus in group B.Conclusions: Addition of intrathecal clonidine prolonged analgesia and decreased morphine consumption postoperatively more than oral clonidine. Hypotension was more pronounced after oral than after intrathecal clonidine. Intrathecal clonidine is therefore recommended.
Effects of propofol on cerebral blood flow and the metabolic rate of oxygen in humans
Authors: Oshima T. , Karasawa F. , Satoh T. 
Published: March 2003

Background: Effects of propofol on human cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), and blood flow‐metabolism coupling have not been fully evaluated. We therefore assessed the effects of propofol on total‐CBF and CMRO2 in patients without noxious stimuli and neurologic disorders.Methods: General anesthesia was induced with midazolam (0.2 mg/kg) and fentanyl (5 µg/kg) in 10 patients (ASA physical status I) undergoing knee joint endoscopic surgery. Epidural anesthesia was also performed to avoid noxious stimuli during surgery. Cerebral blood flow (CBF) and cerebral arteriovenous oxygen content difference (a‐vDO2) was measured using the Kety‐Schmidt method with 15% N2O as a tracer before and after propofol infusion (6 mg/kg/h for 40 min), and the CMRO2 was also calculated.Results: CBF decreased following propofol infusion from 34.4 ml/100 g/min (range 28.4–52.0) to 30.0 ml/100 g/min (range 20.2–42.4) (P=0.04). Although there was no significant change in a‐vDO2, CMRO2 decreased following propofol infusion from 2.7 ml/100 g/min (range 2.2–4.3) to 2.2 ml/100 g/min (range 1.4–3.0) (P=0.04). There was a strong linear correlation between CBF and CMRO2 (r=0.90).Conclusion: Propofol proportionally decreased CBF and CMRO2 without affecting a‐vDO2 in humans, suggesting that normal cerebral circulation and metabolism are maintained.
Influence of non‐volatile anesthetics on the migration behavior of the human breast cancer cell line  MDA‐MB‐468
Authors: Garib V. , Niggemann B. , Zänker K S. , Brandt L. , Kubens B. S. 
Published: March 2003

Background: Anesthetic agents are known to influence functions of the immune system. Anesthetic drugs also support cancer progression by suppressing the activity of immune cells. In breast carcinoma an increase in expression of peripheral‐type benzodiazepine receptors (PBR) and the gamma aminobutyl acid (GABA) level has been discovered. Therefore, an investigation of a direct influence of GABA‐A agonist propofol, GABA‐A and PBR‐agonist etomidate, and the local anesthetic drug lidocaine, which can also bind to the GABA‐A receptor and PBR, on migration of breast carcinoma cells was performed.Methods: MDA‐MB‐468 cells were incubated with anesthetic agents using clinically relevant concentrations (propofol 3, 6, 9 mg/l, etomidate 2, 3, 4 mg/l, and lidocaine 1.25, 2.5, 5 mg/l). Locomotion was investigated in a three‐dimensional collagen matrix using time‐lapse video microscopy and computer‐assisted cell‐tracking.Results: The percentage of migrating cells (57.4±1.9) as well as the velocity (0.22±0.09 µm/min) and distance migrated (89.4±66.8 µm/10 h) increased in the presence of propofol in a dose‐dependent manner (up to 74.4±7.5, 0.30±0.09, 143.8±89.1, respectively) compared with the long chain triglyceride (LCT) control. In contrast, no influence of etomidate on the number of migrating cells could be observed. The velocity and distance migrated at 3 and 4 mg/l were found to be statistically significantly enhanced. Treatment with lidocaine caused an increase in the percentage of migrating cells (up to 75.0±5.6) in velocity dose dependently (up to 0.33±0.06) and in distance migrated (up to 151.5±92.9).Conclusion: These results show that different anesthetic drugs are able to modulate the migratory machinery of human breast carcinoma cells in vitro.
3He‐MRI‐based vs. conventional determination of lung volumes in patients after unilateral lung transplantation: a new approach to regional spirometry
Authors: Markstaller K. , Kauczor H.‐U. , Puderbach M. , Mayer E. , Viallon M. , Gast K. , Weiler N. , Thelen M. , Eberle B. 
Published: March 2003

Background: To use 3Helium (3He)‐MRI in patients with unilateral lung grafts to assess the contributions of graft and native lung to total ventilated lung volume, and second to compare conventional measurements of intrapulmonary gas volume (spirometry, body plethysmography) with image‐based volumetry of ventilated lung parenchyma visualized by hyperpolarized 3He‐MRI.Methods: With Ethics Committee approval, five patients with single lung transplantation (SLTX) for idiopathic pulmonary fibrosis (IPF) underwent both conventional pulmonary function testing (PFT) and 3He‐MRI of the lung. Intrapulmonary gas volume (GV) during the inspiratory breathhold for 3He‐MRI was calculated from measured functional residual capacity (corrected for supine position) and inspired tidal volume. Image‐based global and regional lung volumetries (LV) were performed in three‐dimensionally reconstructed 3He‐MR images (corrected for the fraction of tissue and blood).Results: Transplanted lungs were characterized by a homogeneous distribution of signal intensity, whereas the native lungs of the patients suffering from IPF displayed an inhomogeneous signal distribution pattern with numerous round or wedge‐shaped ventilation defects. Total ventilated lung volume determined by 3He‐MRI correlated well with PFT‐based measurements, but with a systematic overestimation of the 3He‐based lung volumetry of approximately 20%. Functioning lung grafts contributed 66±6% and their corresponding native IPF lungs 34±6% to total ventilated volume (P<0.05; mean±SD).Conclusion: 3Helium‐MRI of the lung offers a novel approach to regional determination of ventilated lung volume, including its blood and tissue compartments. The advantage of this technique over computed tomography or ventilation scintigraphy is the lack of radiation exposure, and hence its repeatability. Follow up of SLTX patients with this new technique may allow the monitoring of functional and structural developments of grafted lungs with better sensitivity and specificity than PFT.
Pulmonary endothelial dysfunction after cardiopulmonary bypass in neonatal pigs
Authors: Glavind‐Kristensen M. , Brix‐Christensen V. , Toennesen E. , Ravn H. B. , Forman A. , Sorensen K. , Hjortdal V. E. 
Published: March 2003

Background: In neonatal pigs cardiopulmonary bypass (CPB) is associated with endothelial dysfunction in isolated large pulmonary arteries. It is, however, of great importance if this functional change extends to the small pulmonary resistance arteries, which are the key regulators of pulmonary flow and pressure. The aim of this study was to assess changes in pulmonary microvascular function after CPB using a clinically relevant pediatric procedure.Methods: From three groups of neonatal pigs (CPB‐, sham‐ and control group) pulmonary resistance arteries and systemic resistance arteries (from skeletal muscle) were isolated and mounted as ring preparations in wire myographs. Vessel diameters were less than 500 µm. Concentration‐response curves were constructed for norepinephrine (NA), vasopressin (Vp), and the thromboxane A2‐analog U46619, while the endothelium‐dependent and ‐independent vasodilator functions were assessed as responses to acetylcholine and nitric oxide (NO).Results: Maximum pulmonary vasodilator response to acetylcholine was attenuated after CPB compared with sham‐operated and control animals (P=0.04). NO‐induced relaxation, and contractile responses to NA, Vp, and U46619 were not influenced by CPB. In systemic arteries no changes in contractile or relaxant responses were seen after CPB.Conclusion: CPB seems to induce pulmonary endothelial dysfunction in pulmonary but not peripheral resistance arteries in neonatal piglets.
Lipid solubility‐ and concentration‐dependent attenuation of in vitro natural killer cell cytotoxicity by local anesthetics
Authors: Krog J. , Hokland M. , Ahlburg P. , Parner E. , Tønnesen E. 
Published: March 2003

Background: Natural killer (NK) cells constitute an essential component of the innate immune system in the defence against infected and malignant cells. In this study the in vitro effect on NK cell activity of three different local anesthetics with different lipid solubility was investigated.Methods: Venous blood from seven healthy volunteers was incubated with three amide local anesthetics with three different concentrations of lipid solubility: lidocaine 0.50, 1.00 and 2.00 mg/ml, ropivacaine 0.375, 0.75 and 1.50 mg/ml, and bupivacaine 0.25, 0.50 and 1.00 mg/ml. After 1 h of incubation, mononuclear cells were isolated and cryopreserved until tested for NK cell cytotoxicity in a 4‐h 51Cr‐release assay against K‐562 target cells. Natural killer cell cytotoxicity of mononuclear cells incubated with isotonic saline was used as the control.Results: A significant suppression in NK cell cytotoxicity was demonstrated for all three local anesthetic agents when the NK cell cytotoxicity was compared with the cytotoxicity estimated after incubation with the isotonic saline (P<0.004). Moreover a significant lipid solubility‐dependent effect (P=0.0001) as well as an overall concentration‐dependent effect (P<0.0001) on the NK cell cytotoxicity was found.Conclusion: The results of the present in vitro study suggest a negative association between the estimated NK cell cytotoxicity and the lipid solubility as well as the concentrations of the three local anesthetic agents tested.