bluuebunny/crossref_metadata_2025 huggingface dataset:
The pharmacodynamics and pharmacokinetics of mivacurium in children
Authors: Østergaard D. , Gätke M. R. , Berg H. , Rasmussen S. N. , Viby‐Mogensen J.
Published: March 2003

Background: In children, onset time and duration of action of mivacurium are shorter than in adults. Some suggest that this is due to differences in plasma cholinesterase (pChe), whereas others indicate that there is no difference. The purpose of this study was to evaluate the pharmacodynamics and pharmacokinetics of mivacurium in phenotypically normal children aged 3–6 and 10–14 years old, respectively.

Methods: Ten children aged 3–6 years and 10 children aged 10–14 years were studied during halothane anaesthesia. Before induction of anaesthesia, a bloodsample was drawn to measure the pChe activity and phenotype. The neuromuscular block was monitored at the thumb using train‐of‐four (TOF) nerve stimulation every 12 s and mechanomyography. The times to different levels of neuromuscular recovery following mivacurium 0.2 mg/kg were recorded. The concentrations in venous blood of the three isomers and the metabolites of mivacurium were measured.

Results: No statistically significant difference was found in pChe activity or in the pharmacodynamics of mivacurium. The onset time was 1.4 min (0.8–1.9) median (range) and 1.3 min (1.1–1.9) and the time to first response to TOF nerve stimulation was 9.6 min (6.5–12.6) and 10.5 min (7.0–14.0) in young and older children, respectively. The pharmacokinetic data were too sparse to allow analysis of the two age groups separately (8 and 8 patients), hence the data were pooled. The median clearances of the cis‐cis, the cis‐trans, and the trans‐trans isomer were 5.5, 51.0 and 30.5 ml/kg/min, respectively.

Conclusion: Our data indicate that there are no major differences in pharmacodynamics or pharmacokinetics of mivacurium between young (3–6 years) and older (10–14 years) children.
Oral ondansetron, tropisetron or metoclopramide to prevent postoperative nausea and vomiting: a comparison in high‐risk patients undergoing thyroid or parathyroid surgery
Authors: Jokela R. , Koivuranta M. , Kangas‐Saarela T. , Purhonen S. , Alahuhta S.
Published: March 2003

Background: Oral antiemetic prophylaxis may be a practical alternative to intravenous administration. Intravenous ondansetron and tropisetron prevent postoperative nausea and vomiting (PONV) at least as efficiently as traditional antiemetics, droperidol and metoclopramide. We tested the hypothesis that the incidence of PONV after oral ondansetron or tropisetron prophylaxis is lower compared with metoclopramide among high‐risk patients.

Methods: In a prospective, double‐blind study we studied 179 high‐risk patients who received either ondansetron 16 mg, tropisetron 5 mg, or metoclopramide 10 mg orally 1 h before the operation. A standard general anesthetic technique and postoperative analgesia were used. The incidence of PONV and the need for rescue antiemetic medication was recorded for 24 h.

Results: In the postanesthesia care unit, the incidence of PONV was lower after premedication with tropisetron compared with ondansetron and metoclopramide (15%, 32% and 39%, respectively). The incidence of PONV during 0–24 h was the same in each group (68%, 58% and 75% in the ondansetron, tropisetron and metoclopramide group, respectively), but the incidence of vomiting was significantly lower after ondansetron (34%) and tropisetron (22%) prophylaxis compared with metoclopramide (53%). The need for additional antiemetics was significantly lower after tropisetron prophylaxis compared with metoclopramide. Patient satisfaction was significantly higher after tropisetron than after metoclopramide.

Conclusions: In the initial period, the incidence of PONV was lower after premedication with oral tropisetron than after ondansetron or metoclopramide. Considering the entire 24‐h postoperative period, the incidence of PONV was the same after all three premedications, but the incidence of vomiting was lower after oral ondansetron and tropisetron than after metoclopramide.
Airway closure in anesthetized infants and children: influence of inspiratory pressures and volumes
Authors: Thorsteinsson A. , Werner O. , Jonmarker C. , Larsson A.
Published: March 2003

Background: Cyclic opening and closing of lung units during tidal breathing may be an important cause of iatrogenic lung injury. We hypothesized that airway closure is uncommon in children with healthy lungs when inspiratory pressures are kept low, but paradoxically may occur when inspiratory pressures are increased.

Methods: Elastic equilibrium volume (EEV) and closing capacity (CC) were measured with a tracer gas (SF6) technique in 11 anesthetized, muscle‐relaxed, endotracheally intubated and artificially ventilated healthy children, aged 0.6–13 years. Airway closing was studied in a randomized order at two inflation pressures, +20 or +30 cmH2O, and CC and CC/EEV were calculated from the plots obtained when the lungs were exsufflated to −20 cmH2O. (CC/EEV >1 indicates that airway closure might occur during tidal breathing). Furthermore, a measure of uneven ventilation, multiple breath alveolar mixing efficiency (MBAME), was obtained.

Results: Airway closure within the tidal volume (CC/EEV >1) was observed in four and eight children (not significant, NS) after 20 and 30 cmH2O inflation, respectively. However, CC30/EEV was >CC20/EEV in all children (P≤0.001). The MBAME was 75±7% (normal) and did not correlate with CC/EEV.

Conclusion: Airway closure within tidal volumes may occur in artificially ventilated healthy children during ventilation with low inspiratory pressure. However, the risk of airway closure and thus opening within the tidal volume increases when the inspiratory pressures are increased.
Neurological outcome after experimental cardiopulmonary resuscitation: a result of delayed and potentially treatable neuronal injury?
Authors: Liu X. L. , Nozari A. , Basu S. , Ronquist G. , Rubertsson S. , Wiklund L.
Published: March 2003

Background: In experimental cardiopulmonary resuscitation (CPR) aortic balloon occlusion, vasopressin, and hypertonic saline dextran administration improve cerebral blood flow. Free radical scavenger α‐phenyl‐N‐tert‐butyl‐nitrone (PBN) and cyclosporine‐A (CsA) alleviate neuronal damage after global ischemia. Combining these treatments, we investigated neurological outcome after experimental cardiac arrest.

Methods: Thirty anesthetized piglets, randomly allocated into three groups, were subjected to 8 min of ventricular fibrillation followed by 5 min of closed‐chest CPR. The combined treatment (CT) group received all the above‐mentioned modalities; group B was treated with balloon occlusion and epinephrine; and group C had sham balloon occlusion with epinephrine. Indicators of oxidative stress (8‐iso‐PGF2α), inflammation (15‐keto‐dihydro‐PGF2α), energy crisis (hypoxanthine and xanthine), and anoxia/hypoxia (lactate) were monitored in jugular bulb venous blood. Neurological outcome was evaluated 24 h after CPR.

Results: Restoration of spontaneous circulation (ROSC) was more rapidly achieved and neurological outcome was significantly better in the CT group, although there was no difference in coronary perfusion pressure between groups. The jugular venous PCO2 and cerebral oxygen extraction ratio were lower in the CT group at 5–15 min after ROSC. Jugular venous 8‐iso‐PGF2α and hypoxanthine after ROSC were correlated to 24 h neurological outcome

Conclusions: A combination of cerebral blood flow promoting measures and administration of α‐phenyl‐N‐tert‐butyl‐nitrone and cyclosporine‐A improved 24 h neurological outcome after 8 min of experimental normothermic cardiac arrest, indicating an ongoing neuronal injury in the reperfusion phase.
Biochemical markers for brain damage after cardiac surgery – time profile and correlation with cognitive dysfunction
Authors: Rasmussen L. S. , Christiansen M. , Eliasen K. , Sander‐Jensen K. , Moller J. T.
Published: March 2003

Background: Cerebral dysfunction is common after cardiac surgery and may be reflected in increasing blood concentrations of neuron specific enolase (NSE) and S‐100β protein. The aim of the study was to determine the optimal timing of blood sampling.

Methods: We studied 15 patients undergoing coronary artery bypass grafting. Serum concentrations of NSE and S‐100β protein were measured before surgery and after 12, 18, 24, 30, and 36 h. Neuropsychological testing was performed before surgery, at discharge from hospital and after 3 months.

Results: Serum concentrations of both NSE and S‐100β protein increased significantly. At the first postoperative test, seven patients had cognitive dysfunction and a significant correlation was found between the composite z‐score and the increase in the NSE level after 36 h (R = 0.76, P=0.001). The median increase in NSE after 36 h was 4.1 µg/l in patients having cognitive dysfunction and 0.9 µg/l in the remaining patients (P<0.05). No significant correlation was found between cognitive dysfunction and the increase in S‐100β protein. After 3 months, no statistically significant correlation was found between either NSE or S‐100β protein and cognitive dysfunction.

Conclusion: NSE seems to be a useful blood marker for early cognitive dysfunction after coronary artery bypass grafting, optimal timing of blood sampling being at approximately 36 h postoperatively.
Cerebral blood flow, oxidative metabolism and cerebrovascular carbon dioxide reactivity in patients with acute bacterial meningitis
Authors: Møller K. , Strauss G. I. , Thomsen G. , Larsen F. S. , Holm S. , Sperling B. K. , Skinhøj P. , Knudsen G. M.
Published: March 2003

Background: The optimal arterial carbon dioxide tension (PaCO2) in patients with acute bacterial meningitis (ABM) is unknown and controversial. The objective of this study was to measure global cerebral blood flow (CBF), cerebrovascular CO2 reactivity (CO2R), and cerebral metabolic rates (CMR) of oxygen (O2), glucose (glu), and lactate (lac), in patients with ABM and compare the results to those obtained in healthy volunteers.

Methods: We studied 19 patients (17 of whom were sedated) with ABM and eight healthy volunteers (controls). CBF was measured during baseline ventilation and hyperventilation with single‐photon emission computed tomography (SPECT) (14 patients) and/or the Kety‐Schmidt technique (KS) (11 patients and all controls). In KS studies, CMR was measured by multiplying the arterial to jugular venous concentration difference (a‐v D) by CBF.

Results: CBF did not differ significantly among groups, although a larger variation was seen in patients than in controls. CO2R was not significantly different among groups. At baseline, patients had significantly lower a‐v DO2, CMR(O2), CMR(glu), and CMR(lac) than controls. CMR(O2) did not change between hyperventilation compared to baseline ventilation, whereas CMR(glu) increased.

Conclusion: In patients with acute bacterial meningitis, we found variable levels of CBF and cerebrovascular CO2 reactivity, a low a‐v DO2, low cerebral metabolic rates of oxygen and glucose, and a cerebral lactate efflux. In these patients, a ventilation strategy guided by jugular bulb oximetry and/or repeated CBF measurements may be more optimal in terms of cerebral oxygenation than a strategy aiming at identical levels of PaCO2 for all patients.
Local metabolic changes in subcutaneous adipose tissue during intravenous and epidural analgesia
Authors: Ederoth P. , Flisberg P. , Ungerstedt U. , Nordström C.‐H. , Lundberg J.
Published: March 2003

Background: This clinical study aimed at investigating the impact of postoperative thoracic epidural analgesia on extracellular glycerol concentration and glucose metabolism in subcutaneous adipose tissue, using the microdialysis technique. The sympathetic nervous activity, which can be attenuated by epidural anesthesia, influences lipolysis and the release of glycerol.

Methods: Fourteen patients who underwent major abdominal or thoraco‐abdominal surgery were studied postoperatively over 3 days. For postoperative analgesia the patients were prospectively randomized to receive either thoracic epidural analgesia with a bupivacaine/morphine infusion (EPI‐group, n=6) or a continuous i.v. infusion of morphine (MO‐group, n=8). The concentration of glycerol, glucose and lactate in the abdominal and deltoid subcutaneous adipose tissue were measured using a microdialysis technique.

Results: The abdominal glycerol levels were equal in both groups. In the deltoid region of the EPI‐group, glycerol concentrations started to increase on Day 2, and reached significantly higher levels on Day 3 compared with the MO‐group. The glucose and lactate levels showed no differences between groups in the two regions.

Conclusion: The uniform glycerol levels in abdominal subcutaneous adipose tissue in conjunction with the difference in glycerol levels in the deltoid area indicate that the local lipolysis is different in the two study groups. This might be explained by a regional metabolic influence of thoracic epidural analgesia, possibly via the sympathetic nervous system.
Heart rate to arterial pressure impulse response during one lung ventilation
Authors: Kawamoto M. , Hidaka S. , Kurita S. , Yuge O. , Kawamoto N.
Published: March 2003

Background: Although one lung ventilation (OLV) is commonly used, little is known about the modulation of the autonomic nervous system with OLV while under general anesthesia. As the frequency domain and time domain analyses are powerful analytic tools, we investigated their modulation during OLV.

Methods: Patients undergoing thoracic surgery were classified into two groups: those who did (group A, n=8) and those who did not (group N, n=8) receive atropine. After a double lumen tube was placed endotracheally, mechanical ventilation of both lungs (BLV) was established at 18 min−1 while under isoflurane anesthesia. Electrocardiogram, systolic arterial pressure (SAP), and inspiratory flow (Finsp) were digitally recorded as follows: awake before anesthesia; BLV after anesthesia; BLV after intravenous 10 µg kg−1 of atropine (group A) or not (group N); left OLV; and right OLV. Power spectral analyses of heart rate (HR) and SAP were computed by determining low‐(LF, 0.04–0.15 Hz) and high‐frequency (HF, 0.15–0.40 Hz) components, and impulse response analysis was executed among HR, SAP, and Finsp. Impulse responses were assessed by the maximum values in the time domain.

Results: In frequency domain analysis, atropine depressed LF and LF/HF but not HF in HR variability, while no difference was observed between right OLV and left OLV. The heart rate to SAP impulse response was maintained at a significantly higher level in group A than in group N (905±360 vs. 425±375 mmHg beats−1min−1) at right OLV. A significant difference was also observed between left and right OLV within group N.

Conclusion: Impulse response analysis demonstrated that there is a greater effect on autonomic nervous system modulation during right OLV than in left OLV, which mainly results from a parasympathetic neural linkage origin.
Altered response to intravenous thiopental and succinylcholine in acute amphetamine abuse
Authors: Stibolt O. , Wachowiak‐Andersen G.
Published: March 2003

Substance abuse has become increasingly prevalent: illegal drugs have profound and varied physiologic effects which create a large potential for anesthetic problems and complications (1). Amphetamine is a strong sympathomimetic and may therefore influence the course of anesthesia. We report the case of a patient with acute amphetamine abuse presenting difficulties during anesthesia.
Catheter‐related epidural abscesses – Don't wait for neurological deficits
Authors: Royakkers A. A. N. M. , Willigers H. , Van Der Ven A. J. , Wilmink J. , Durieux M. , Van Kleef M.
Published: March 2003

Epidural abscess is a rare but serious complication of epidural anesthesia for peri‐ and postoperative analgesia. It is feared because of possible persistent neurological deficits. Epidural abscess presents mostly with a classic triad of symptoms: back pain, fever and variable neurological signs and symptoms. When neurologic signs or symptoms develop, MRI scanning is the diagnostic procedure of choice. The therapy of choice is intravenous antibiotics for more than 4 weeks with or without a laminectomy or drainage.

In the present paper we describe three patients with epidural abscesses presented during a time period of 1 year in our hospital. In each case, patients developed local signs of infection and systemic signs, but no neurological symptoms.

Based on these cases and a review of the literature, we propose that MRI scanning should be strongly considered when patients present with systemic and local signs, even in the absence of neurological deficits.
Total intravenous anaesthesia and the use of an intubating laryngeal mask in a patient with osteogenesis imperfecta
Authors: Karabiyik L. , Parpucu M. , Kurtipek Ö.
Published: March 2003

Osteogenesis imperfecta is a genetically determined rare disease of the connective tissue, associated with abnormalities of type 1 collagen. The primary bone lesion is the lack of normal ossification of the endochondrial bone. Patients with osteogenesis imperfecta present several problems for anaesthetists. They have a tendency to develop malignant or non‐malignant hyperthermia. During laryngoscopy and tracheal intubation, the mandible, teeth and cervical spine may be fractured or injured, and mucosal bruising or bleeding may occur. Renal or ureteral stones are common. The main problems are thus with airway control and intubation, and the risk of anaesthetic agents triggering malignant hyperthermia. We describe the successful anaesthetic management of a patient with osteogenesis imperfecta, undergoing nephrolithotomy and ureterolithotomy with total intravenous anaesthesia including propofol, remifentanil and cisatracurium, using an intubating laryngeal mask.
Post spinal meningitis and asepsis
Authors: Videira R. L. R. , Ruiz‐Neto P. P. , Brandao Neto M.
Published: March 2003

Background:  Post spinal meningitis (PSM) is a complication still currently being reported. After two PSM cases in our hospital an epidemiological study was initiated, which included a survey of techniques for asepsis that are applied in our department.

Methods:  Cases defined as PSM comprised meningitis within a week after spinal anesthesia. Anesthesia records, anesthesia complication files and the records of the Hospital Commission for Infection Control from 1997 to 2000 were reviewed. Asepsis techniques applied were surveyed by a questionnaire answered by all our department's anesthesiologists. The equipment and procedures for spinal anesthesia were listed. Current anesthesia textbooks were reviewed for recommendations regarding asepsis techniques in conjunction with spinal anesthesia.

Results:  Three cases of PSM were identified following 38,128 spinal anesthesias whereas none was observed in 12,822 patients subjected to other types of regional or general anesthesia (P>0.05). Culture of cerebrospinal fluid yielded Streptococcus in two patients and was negative in the other patient. The asepsis technique applied by the anesthesiologists varied considerably. The literature review showed that aspects on asepsis for spinal anesthesia are poorly covered.

Conclusion:  The incidence of meningitis was similar in patients subjected to spinal anesthesia and in those subjected to other anesthetic techniques. Asepsis techniques were found to differ considerably among our staff members, reflecting the lack of well‐defined published standards for this procedure. We recommend that asepsis for spinal anesthesia should not be less rigorous than for surgical asepsis.
Electrophysiologic cardiac effects of the new local anesthetic IQB‐9302 and of bupivacaine in the anesthetised dog
Authors: Gomez De Segura I. A. , Vazquez I. ,   Moreno‐Planas, Benito J. , Galiano A. , De Miguel E.
Published: March 2003

Background:  Local anesthetics are not free from potentially fatal complications. Therefore every new local anesthetic should be tested to demonstrate a lower, or at least similar, degree of toxicity over clinically used analogs. Most toxic effects from local anesthetics affect the cardiac electrophysiologic function, so the aim of this study was to characterize the electrophysiologic effects of a new long‐acting local anesthetic (IQB‐9302, Ciprocaine), and compare them with those of bupivacaine in the anesthetized dog.

Methods:  Eight Beagle dogs received three increasing infusion doses of either IQB‐9302 or bupivacaine. Under isoflurane anesthesia, dogs were instrumented to monitor cardiovascular (cardiac output, arterial and venous blood pressures) and cardiac electrophysiologic data (sinus and atrioventricular (AV) node function, atrial, nodal and ventricular conduction times, and refractoriness).

Results:  Only the highest dose of both drugs induced hemodynamic or electrophysiologic alterations: cardiac output and heart rate were reduced while blood pressures remained unchanged. Atrial and intranodal conduction times and atrial refractoriness increased similarly with both anesthetics, but to a slightly lesser extent with IQB‐9302. Significant increases in His‐Purkinje and intraventricular conduction times were the most severe noxious effects and occurred only with large doses of either drug. IQB‐9302 was slightly less toxic than bupivacaine and, unlike this latter drug, potentially fatal arrhythmias were not induced.

Conclusion:  IQB‐9302 has hemodynamic and cardiac electrophysiologic effects similar to those caused by bupivacaine. Nevertheless, slightly less toxic effects were derived from IQB‐9302 administration than with bupivacaine, and, unlike the latter, the former might be less proarrhytmogenic. The new long‐acting local anesthetic IQB‐9302 may offer clinical advantages compared with bupivacaine.
Pharmacokinetics and pharmacodynamics of mivacurium in young adult and elderly patients
Authors: Østergaard D. , Viby‐Mogensen J. , Pedersen N. A. , Holm H. , Skovgaard L. T.
Published: March 2003

Background:  Mivacurium is hydrolyzed by plasma cholinesterase, and is therefore less dependent on liver metabolism and renal elimination than other neuromuscular blocking drugs. This might favor the use of mivacurium in elderly patients. The purpose of this study was to compare the pharmacodynamics and the pharmacokinetics of the three isomers of mivacurium and their metabolites in young adult and elderly patients.

Methods:  Sixty‐four patients were included in a dose–response study, in which 32 young adults and 32 elderly patients received one of four doses of mivacurium. An additional bolus dose of mivacurium to a total of 0.1 mg/kg was given followed by a continuous infusion adjusted to maintain a 91–99% neuromuscular block. The times to maximum block and different levels of recovery were measured using mechanomyography and train‐of‐four (TOF) nerve stimulation. Thirty‐two patients were randomly selected for the pharmacokinetic study. Venous samples were taken for determination of the three mivacurium isomers and the metabolites.

Results:  The estimated ED95 were 0.053 and 0.061 mg/kg in young adults and elderly patients, respectively (NS). The median infusion rate did not differ, but duration to a TOF ratio of 0.7 was significantly longer in elderly patients than in young adult patients (21.0 vs. 16.5 min). No statistically significant difference between the age groups in clearance and elimination half‐life of the isomers was seen. The half‐lives of the metabolites were significantly prolonged in the elderly patients.

Conclusion:  There were no significant differences in the potency or infusion requirements between the adult and elderly patients, but the rate of recovery was significantly, though only moderately prolonged, in the elderly patients. No significant difference in clearance was seen but the elimination half‐lives of the metabolites was longer in the elderly patients.
Myocardial tissue oxygen during coronary artery constriction and hypotension in dogs
Authors: Hoffman W. E. , Albrecht R. F. , Jonjev Z. S.
Published: March 2003

Background: Sodium nitroprusside (SNP) may decrease myocardial tissue oxygenation in dogs with normal coronary arteries. We compared SNP‐ with desflurane‐induced hypotension on myocardial tissue oxygen and pH in dogs with left anterior descending artery constriction.

Methods: Twenty‐four dogs were anesthetized with 8% desflurane for baseline anesthesia. Catheters were inserted into the femoral artery and vein and the coronary sinus. A flow probe and flow restriction device was placed on the left anterior descending (LAD) artery. A probe that measured myocardial oxygen pressure was inserted into the middle myocardium in the LAD region. Baseline measures were made of LAD artery flow, arterial and coronary sinus blood gases, and myocardial tissue gases. A 30% decrease in blood pressure was induced with SNP with unrestricted LAD flow (n=6) or when LAD artery flow was restricted by 30% from baseline (n=6). In separate dogs, a 30% decrease in blood pressure was produced with 14 ± 1% desflurane with unrestricted LAD flow (n=6) or with baseline LAD artery flow restricted by 30% (n=6).

Results: During SNP‐induced hypotension with no LAD constriction, LAD artery flow and coronary sinus oxygen tension increased but myocardial tissue oxygen tension (PmO2) decreased by 40%. When baseline artery flow was decreased by 30% by LAD constriction, SNP‐induced hypotension decreased tissue oxygen pressure by 80%, and ischemic acidosis was produced. During unrestricted LAD artery flow or with a 30% flow restriction, desflurane‐induced hypotension produced no significant change from baseline myocardial tissue oxygen tension or pH.

Conclusion: During coronary artery constriction, desflurane‐induced hypotension maintained myocardial tissue oxygenation and pH better than did SNP‐induced hypotension. The divergence between tissue and coronary sinus oxygen tension during SNP suggests that arteriovenous shunting may occur.
Hepatic function during xenon anesthesia in pigs
Authors: Reinelt H. , Marx T. , Kotzerke J. , Topalidis P. , Luederwald S. , Armbruster S. , Schirmer U. , Schmidt M.
Published: March 2003

Background: Inhalation anesthetics decrease liver perfusion and oxygen consumption by changing the distribution pattern of perfusion between the hepatic artery and the portal vein and by direct effects on liver cells. The effects of xenon on liver perfusion and function have been not investigated until now.

Methods: Fourteen pigs were randomly assigned to two groups to receive either 73–78% xenon or 75% nitrogen in oxygen with additional supplementation of pentobarbital and buprenorphine. Microspheres were used to determine the arterial perfusion of the liver and splanchnic organs. Oxygen contents were measured by catheterization of the portal and a liver vein. Lactate and glucose plasma concentrations were measured in hepatic, mixed venous and arterial blood. Alanine aminotransferase (ALT) and lactate dehydrogenase (LOH) plasma concentrations were measured in arterial blood. Urea production rates were calculated to assess hepatic metabolic function.

Results: Significant higher oxygen contents were found in the liver venous blood during xenon anesthesia. No differences were found in any other investigated parameters.

Conclusion: Higher oxygen content in liver venous blood observed during xenon anesthesia was not induced by changes in hepatic perfusion distribution or by an impairment of liver metabolic capacity. However, it can be explained by similar results known from inhalation anesthesia. Additionally, the effect can be caused by the reduction of plasma catecholamine concentrations during xenon anesthesia.
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.
Malignant bladder tumor transurethral resection in a patient with acquired C1 inhibitor deficiency
Authors: Alonso J. M. , Fas M. J.
Published: March 2003

Acquired C1‐INH deficiency or acquired angiodema (AAE) is an uncommon cause of angiedema that can induce severe airway complications during surgical procedures. We present the perioperative management of a patient with AAE secondary to a malignant bladder tumor. Anesthetic guidelines could be useful in the management of this disorder.
Epidural blood patch for treatment of spontaneous intracranial hypotension
Authors: Waguri N. , Tomita M. , Hayatsu K. , Okamoto K. , Shimoji K.
Published: March 2003

Spontaneous intracranial hypotension is an uncommon disease caused by cerebrospinal fluid leakage. We reported a case of a 42‐year‐old male with postural headache who was diagnosed as having spontaneous intracranial hypotension. His headache did not completely improve by conservative therapies, so he underwent an autologous epidural blood patch. The site of cerebrospinal fluid restoration was identified at the level from the C2 to Th7 epidural space by 111In‐DPTA cisternography and computed tomography coupled with myelography, and cervical EBP was performed. Because cerebrospinal fluid drops from the catheter, it is useful to identify the location of the catheter tip under contrast injection X‐ray. Rapid and dramatic relief from the headache was obtained, and no serious complications occurred.
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.