bluuebunny/crossref_metadata_2025_split huggingface dataset:
A porcine model for evaluation of cerebral haemodynamics and metabolism during increased intracranial pressure
Authors: Nilsson F. , ÅKeson J. , Messeter K. , Ryding E. , Rosén I. , Nordström C.‐H. 
Published: January 2009

In patients with severe head injuries raised intracranial pressure (ICP) constitutes the most important cause of mortality. Several new therapies for increased ICP have recently been suggested and it is of importance to study the physiological effects of these treatments in animal experiments during steady state conditions. A porcine model for evaluation of cerebral haemodynamics and metabolism during increased ICP is presented. Intracranial hypertension was induced by inflation of two tonometric gastric balloons placed extradurally covering a major part of the parietooccipital region bilaterally. The distribution of the blood flow supplied by the carotid artery used for the cerebral blood flow (CBF) measurements was studied by intraarlerial (i.a.) injection of 99mTc‐HMPAO.The measurements showed that following ligation of the external carotid and the occipital artery no accumulation of tracer substance occurred in extracranial tissues during normal or increased ICP. Cerebral physiological variables (CBF, Cavo2, and ICP) were measured 5, 20 and 60 rnin after induction of intracranial hypertension. The results confirm that the experimental situation gives a reproducible increase in ICP (25–28 mm Hg) and that the physiological variables remain stable during the period of intracranial hypertension. We conclude that the model simulates the effects of an acute intracranial focal mass and is well suited for the evaluation of different pharmacological therapies of increased ICP.
Respiratory changes during treatment of postoperative pain with high dose transdermal fentanyl
Authors: Bülow H. H. , Linnemann M. , Berg H. , Lang‐Jensen T. , LaCour S. , Jonsson T. 
Published: January 2009

This study made a longterm (72 hours) evaluation of the efficacy and possible side‐effects of transdermal delivery of fentanyl (TTS‐system) for post‐operative pain relief.The study was double‐blind, placebo‐controlled with either a TTS‐system delivering fentanyl 100 μg · h‐1 and rescue analgesic on demand or a placebo system and analgesic on demand. Analgesic consumption, pain, general satisfaction, respiratory rate, and levels of SpO2 and tcCO2 (pulse oximetry and transcutaneous CO2 measuring) were evaluated. Recruitment was stopped after enrolment of 24 patients, on safety grounds. The Fentanyl group was more satisfied with postoperative pain relief (P= 0.008); they had a lower analgesic demand (P<0.05) but also a lower respiratory rate (P<0.05) and a higher level of tcCO2 23 hours after application (P<0.05).There were three cases (25%) of increased PaCO2 (>6.5 kPa) in the Placebo group but without low PaO2 levels, sedation or bradypnoea. Conversely, there were three cases (33%) in the Fentanyl group with bradypnoea (<10 breaths/minute), two without influence on PaO2 or PaCO2, but one (no. 24) with bradypnoea, heavy sedation, a marked decrease in PaO2 (5.8 kPa) and increased PaCO2 (7.5 kPa). These findings terminated the study. The 100 μg transdermal fentanyl system is agreeable to the patients, but apparently too potent for routine postoperative pain relief due to a risk of respiratory depression. Respiratory frequency can not be relied upon as sole indicator of insufficient respiration.
Disturbance of hepatocellular integrity associated with propofol anaesthesia in surgical patients
Authors: Tiainen P. , Lindgren L. , Rosenberg P. H. 
Published: January 2009

Propofol anaesthesia has not been associated with any hepatic consequences. We used glutathione transferase Alpha (GSTA), a very sensitive indicator of hepatocellular integrity, to evaluate the effect of propofol on the liver. Total intravenous anaesthesia was induced and maintained with propofol without any supplements in 30 female patients undergoing breast surgery. Ten healthy female volunteers given the lipid vehicle of propofol served as controls. Serum GSTA concentration was measured with a sensitive time‐resolved immunorluorometric assay. Total intravenous propofol anaesthesia was stable and postoperative nausea negligible. A significant increase in GSTA from 3.1 μg · 1 ‐1 (mean baseline) to 10.0 μg · 1 ‐1 (mean peak) was noted after propofol infusion, indicating subclinical disturbance in hepatocellular integrity. No change in aminotransferases and no clinical signs of hepato‐toxicity were observed. A small increase in GSTA from 2.4 μg · 1‐1 (mean baseline) to 4.1 μg· 1‐1 (mean peak) was observed during lipid infusion.We detected a subclinical disturbance in hepatocellular integrity after propofol anaesthesia for breast surgery. The mechanisms of hepatocellular impairment are not clear but the lipid vehicle of propofol alone does not explain it.
Effects of dihydroergotamine on cerebral circulation during experimental intracranial hypertension
Authors: NilssonM.D. F. , Messeter K. , Grände P.‐O. , Rosén I. , Ryding E. , Nordström C.‐H. 
Published: January 2009

Different cerebral vasoconstrictors have recently been suggested for the treatment of raised intracranial pressure (ICP) in patients with severe traumatic brain lesions. Such treatment may be associated with severe side effects. A porcine model simulating an intracranial mass lesion was utilized to examine the haemodynamic cerebral effects of dihydroergotamine (DHE), a recently introduced pharmacological treatment for raised intracranial pressure. Intracranial hypertension was induced by inflation of two tonometric gastric balloons placed extradurally covering the parieto‐occipital region bilaterally. The animals were randomized into one group with six animals receiving 1.0 mg of DHE i.v. followed by a continuous infusion of 0.2 mg/h (high dose) and another group of six animals receiving 0.15 mg i.v. followed by 0.03 mg/h (low dose). Measurements of cerebral blood flow (CBF) and arterio‐venous difference in oxygen content (Cavo2) were performed 5, 20, and 60 min after the DHE infusion. Intracranial pressure (ICP), mean arterial blood pressure (MAP) and cerebral electrical activity (EEG) were recorded continuously.In both groups infusion of DHE caused a lasting decrease in ICP probably achieved mainly by a decrease in cerebral blood volume due to constriction of both arterial and venous capacitance vessels. In the group treated with high‐dose DHE, but not in that given low‐dose DHE, a progressive increase in Cavo2, a fall in jugular venous pH and an increase in EEG delta activity were observed indicating cerebral hypoxia. The study supports the view that DHE may be a valuable tool in the pharmacological treatment of increased ICP in traumatic brain lesions but underscores the importance of a proper dosage.
Cerebral haemodynamic effects of dihydroergotamine in patients with severe traumatic brain lesions
Authors: Asgeirsson B. , Grande P. O. , Nordström C. H. , Messeter K. , Sjöholm H. 
Published: January 2009

Dihydroergotamine (DHE) is used in our recently introduced therapy of post‐traumatic brain oedema and is suggested to reduce ICP through reduction in both cerebral blood volume and brain water content. This study aims at increasing our knowledge of the mechanisms behind the ICP reducing effect of DHE by analysing cerebrovascular effects of a bolus dose of DHE in severely head injured patients (GCS<8). Mean hemispheric cerebral blood flow (CBF) calculated from the clearance of i.v. 133Xenon, ICP, and cerebral arterio‐venous difference in oxygen content (AVDO2), were measured before and after hyperventilation and after a bolus dose of DHE (4 μg/kg). The patients were divided into two groups, one with preserved and one with impaired cerebrovascular CO2‐reactivity to hyperventilation, the latter being predictive of poor outcome. The haemodynamic effects of DHE were compared to those of hyperventilation. Regional CBF and brain volume SPECT measurements were performed in two patients.DHE increased cerebrovascular resistance (CVR) by about 20% and significantly reduced ICP in both groups of patients, resulting in unchanged AVDO2. Hyperventilation with preserved CO2‐reactivity caused a similar decrease in ICP as by DHE but with a much larger increase in CVR (by 70%) and a substantial increase in AVDO2. Hyperventilation with impaired CO2‐reactivity reduced ICP but otherwise had no significant cerebrovascular effects.The study supports the concept that the ICP reducing effect of DHE results more from constriction of the large veins than from arterial vasoconstriction, also implying a relatively smaller risk of ischaemia with DHE than with hyperventilation.
Peripheral blood flow in the elderly during inhalational anaesthesia
Authors: Dwyer R. , Howe J. 
Published: January 2009

We investigated whether aging altered the peripheral vascular effects of inhaled anaesthetic agents. Forearm blood flow (FBF) was measured in 20 young (18–34 yrs) and 21 healthy elderly (60–79 yrs) patients receiving isoflurane or halothane with 66% nitrous oxide (N2O) in oxygen (O2). After etomidate 0.3 mg/kg and vecuronium 0.1 mg/kg, the trachea was intubatcd and controlled ventilation instituted with 66% N2O in O2. Halothane or isoflurane were administered to achieve end‐tidal concentrations of 0.5% halothane or 0.9% isoflurane after 20 min. FBF was measured by venous occlusion plethysraography during the 20 min study period. Induction of anaesthesia with etomidate decreased FBF below baseline (awake) values in both elderly and young; intubation returned FBF to baseline values in the young but not in the elderly. FBF decreased below baseline values in young and elderly patients receiving halothane and in elderly patients receiving isoflurane but not in young patients receiving isoflurane. FBF was significantly greater in young patients receiving isoflurane than halothane after 20 min administration.We conclude that perfusion of forearm muscle and skin is maintained in the young but not in the elderly during anaesthesia with isoflurane/N2O. Perfusion of forearm muscle and skin decreases in both young and elderly patients during anaesthesia with halothane/N2O. The cardiovascular effects of isoflurane/N2O and halothane/ N2O did not differ significantly in healthy elderly patients.
Oxygen tension‐associated changes on secondary immune response in halothane or isoflurane anesthetized mice
Authors: Puig N. R. , Elena G. A. , Barragán J. , Comba J. O. , Amerio N. 
Published: January 2009

The impact that reexposure to anesthetics delivered in 100% oxygen or in synthetic air (21% oxygen/79% nitrogen) has on the secondary humoral immune response to sheep red blood cells was studied. Mice were immunized twice with a 15‐day interval and anesthetized immediately after each antigenic challenge with 1.5% halothane or 1.5% isoflurane for 40 min. Halothane in oxygen resulted in increased numbers of IgG‐secreting cells (IgG‐SC), while halothane in air depressed the response when compared to control mice. In contrast, isoflurane vaporized in oxygen did not affect IgG‐SC numbers, while isoflurane given in air lowered the response. Furthermore, neither 100% oxygen, nor the stress of being in an anesthesia chamber breathing synthetic air for 40 min had any immunological effect in non‐anesthetized mice.The inspired oxygen concentration during halothane or isoflurane anesthesia has an effect on the secondary immune response. The effect is different between halothane and isoflurane, possibly due to differences in the extent of their metabolic and pharmacodynamic properties.
Hemodynamic changes due to Trendelenburg positioning and pneumoperitoneum during laparoscopic hysterectomy
Authors: Hirvonen E. A. , Nuutinen L. S. , Kauko M. 
Published: January 2009

More prolonged gynecological laparoscopic operations are being performed in recent years, and a steeper head‐down position is required. The early reports of hemodynamic changes during gynecologic laparoscopy are conflicting, and the effects of anesthesia, head‐down tilt and pneumoperitoneum have not been clearly separated. Invasive hemodynamic monitoring was carried out in 20 female ASA Class I‐II patients who underwent laparoscopic hysterectomy. Baseline measurements were made in the supine, supine‐lithotomy and Trendelenburg (25 30 degrees) positions in awake patients. Measurements were repeated in the supine‐lithotomy and Trendelenburg positions after induction of anesthesia, during laparoscopy 5 minutes after the beginning of peritoneal CO2‐insufflation (intra‐abdominal pressure 13–16 mmHg) and at 15‐minute intervals thereafter, after laparoscopy in the Trendelenburg and supine positions, after extubation and in the recovery room at 30‐minute intervals. Patients received balanced general anesthesia with isoflurane in 35% O2 in an oxygen/air mixture. End tidal PGO2 was maintained between 4.5–4.8 kPa (33—36 mmHg) by changing the minute volume of controlled ventilation.The Trendelenburg position in awake and anesthetized patients increased pulmonary arterial pressures (PAP), central venous pressure (GVP) and pulmonary capillary wedge pressure (PCWP). These pressures increased further at the start of CO2‐insufflation, decreased towards the end of the laparoscopy and reached pre‐insufflation levels after deflation of pneumoperitoneum. The mean arterial pressure (MAP) increased at the beginning of laparoscopy in comparison with the pre‐laparoscopic values. Heart rate (HR) was quite stable during laparoscopy. The cardiac index (CI) decreased with anesthesia from 3.8 to 3.2 1 · min‐1 · m‐2 and further during laparoscopy to 2.7 1 · min‐1 · m‐2, returning to pre‐insufflation values soon after deflation. The stroke index (SI) changed in concert with the GI changes. The right ventricular stroke work index decreased during laparoscopy more than the left ventricular stroke work index. The right atrial pressure (GVP) exceeded the PCWP more often during laparoscopy than during any other phase of the procedure.Anesthesia and the Trendelenburg position increased the CVP, PCWP and pulmonary arterial pressures and decreased cardiac output. Pneumoperitoneum increased these pressures further mostly in the beginning of the laparoscopy, and cardiac output decreased towards the end of the laparoscopy. The risk of systemic CO2‐embolus was increased during laparoscopy.
Effects of temperature on somatosensory evoked potentials during open heart surgery
Authors: Yang L.‐C. , Jawan B. , Chang K. K.‐A. , Lee J. H. 
Published: January 2009

Somatosensory evoked potentials (SEPs) have been found to be useful for early detection of brain ischemia during hypothermic cardiopulmonary bypass in cardiac surgery. However, the relationship between temperature and latency period remains unclear. We prospectively analyzed SEPs obtained during hypothermic cardiopulmonary bypass in 20 patients who had valvular replacement.We concluded that i) a linear correlation was found between temperature and latency period during cooling and rewarming, ii) no hysteresis effect existed in cooling and rewarming, iii) there was a greater hypothermic effect on the synaptic transmission than on the conduction velocity, and, iv) age had also more profound effect on relationship between temperature and latency of SEPs.
Increase of Interleukin‐6 plasma concentrations and HLA‐DR positive T‐lymphocytes after hypotensive anaesthesia with sodium nitroprusside
Authors: Heesen M. , BachmannMennenga B. , Zeiler D. , Mahler M. , Hempelmann G. 
Published: January 2009

Interleukin‐6 (IL‐6), a cytokine involved in the pathogenesis of sepsis and septic shock, and lymphocyte subpopulations were measured in blood circulation of patients receiving sodium nitroprusside (SNP) for induction of hypotension. The aim of this study was to evaluate whether this procedure influences distribution of lymphocyte subsets and IL‐6 response.30 patients of ASA physical status I and II scheduled for nose‐septum correction were randomly assigned to the SNP‐ or control group (without SNP). Patients were anaesthetized with fentanyl, etomidate and isoflurane in 66% nitrous oxide. SNP was administered continuously during 60 min and mean arterial blood pressure was reduced to 50 mmHg. Before and after induction of anaesthesia, 60 min after the beginning of the operation (end of SNP‐infusion) and on the first postoperative day, IL‐6 plasma concentrations were determined by ELISA. The percentages of B‐, T‐lymphocytes, T‐helper, T‐suppressor cells and HLA‐DR positive (activated) T‐lymphocytes were examined by direct immunofluorescence using monoclonal antibodies.On the first day after surgery IL‐6 plasma concentrations were significantly elevated in the SNP‐group compared to preoperative values. In this group the values were higher than in control patients [30.5 (10.9–47.5) pg/ml vs. 17.4 (8.5 21.5) pg/ml]. The percentage of HLA‐DR positive T‐cells was 25.8±4.9% in the patients with SNP on the first postoperative day; it was significantly higher than in control patients [16.5±3.7%]. We conclude that SNP‐administration increases percentage of activated T‐cells and IL‐6 secretion.
The effects of multiple small doses of exogenous surfactant on experimental respiratory failure induced by lung lavage in rats
Authors: Alvarez F. J. , Alfonso L. F. , Gastiasoro E. , Lopez‐Heredia J. , Arnaiz A. , Valls‐i‐Soler A. 
Published: January 2009

Aim:To test the effect on pulmonary gas exchange and mechanics of multiple small doses of exogenous surfactant as an alternative to bolus delivery in experimental respiratory failure induced by lung lavage.Methods:After anesthesia, tracheostomy and constant volume ventilation, respiratory failure was induced by lung lavage in 20 rats. Animals were randomly assigned to an untreated control group or two experimental groups. Equal total doses of modified porcine surfactant (200 mg ·kg‐1 body weight,) were given by tracheal instillation, either as a single bolus or in four (50 mg·kg‐1 b.w.) fractional doses at 10‐min intervals. Arterial pH and blood gases, and peak inspiratory pressure (PIP) were measured.Results:After lavage, a rapid decrease in arterial pH and PaO2, and an increase in PaCO2 and PIP were observed in all animals. In both surfactant‐treated groups, PaO2 increased after surfactant instillation, and remained significantly higher than controls throughout the experiment. Arterial pH was significantly higher and PaCO2 significantly lower only in the single bolus group. In the multiple dose group, these levels were similar to those of controls.Conclusions:In surfactant‐depleted rats with respiratory failure, instillation of four fractional surfactant doses did not result in the same enhancement on gas exchange and PIP, in the following 60 min, as same total dose given by a single bolus.
Premedication with promethazine and transdermal scopolamine reduces the incidence of nausea and vomiting after intrathecal morphine
Authors: Tarkkila P. , Törn K. , Tuominen M. , Lindgren L. 
Published: January 2009

Intrathecal morphine provides effective postoperative pain relief in major orthopaedic surgery. Its use, however, is associated with unpleasant side effects like nausea and vomiting. The effect of different premedications on postoperative emetic sequelae induced by intrathecal morphine was studied in a prospective, double blind study. Sixty patients scheduled for arthroplasty surgery of the lower extremity were anaesthetized with spinal anaesthesia with a combination of isobaric bupivacaine 20 mg and morphine 0.3 mg. For premedication the patients were randomised to three groups of equal size. They received either oral diazepam (5 15 mg), oral promethazine (10 mg) or a combination of promethazine and transdermal scopolamine (1.5 mg).Sixty percent of the patients with both promethazine and transdermal scopolamine were totally free from postoperative nausea and vomiting (PONV) symptoms compared to those premedicated with diazepam (40%) or promethazine alone (30%). Promethazine together with transdermal scopolamine reduced significantly the number of patients with vomiting (to 25%) and also vomiting episodes. This combination was also more efficient in reducing the incidence of nausea (to 25%) and nausea episodes than promethazine alone (P<0.05). Combination also reduced the requests for additional pain relief (P<0.05). PONV occurred in a majority of patients during the first 12 hours of the 24 hour study period and the need for additional analgesics thereafter. The incidence of itching (50–65%) and urinary catheterisation (55–70%) was similar in all groups.In conclusion, the combination of oral promethazine and transdermal scopolamine was most effective in reducing PONV symptoms and also reduced the need for postoperative pain treatment.
Caffeine‐halothane accuracy in MH testing
Authors: HWANG F. , CHUN K. , ANTOGNINI J. F. , GRONERT G. A. 
Published: January 2009

The accuracy and stability of caffeine and halothane concentrations in liquid Krebs medium were examined. Caffeine‐Krebs Ringer's solution in incremental concentrations from 0.25 to 10 mM (N=8 for each concentration) was serially assayed over a three‐year period. Storage was at 4°C. For serial testing of halothane during a five month period, halothane 1% or 3% in carbogen was bubbled through a Krebs solution, contained in muscle baths, either using a roller pump (to eliminate vaporizer back pressure) or using carbogen at a line pressure of 4‐6 lbs/in2 (27‐41 kPa). Halothane in Krebs was asssyed by high pressure liquid chromatography. Caffeine concentrations did not vary for 20 weeks. From then, through 60 weeks, concentrations less than 2 mM steadily diminished; after that, through 156 weeks, only 4, 8, and 10 mM were stable. When compared to the halothane concentration in gas entering the muscle baths, halothane concentration in Krebs was predictable regardless of method delivery, as long as a gas analyzer indicated the proper concentration.We conclude that caffeine solutions are stable for 20 weeks when refrigerated, and for three years at concentrations 4 mM or greater.
Intra‐arterial regional anaesthesia for hand surgery with alkalinized 0.5% lignocaine
Authors: KOSCIELNIAK‐NIELSEN Z. J. , STENS‐PEDERSEN H. L. , KJAERBO E. J. 
Published: January 2009

Intra‐arterial regional anaesthesia (IARA) for hand surgery is an old, forgotten technique. One of the causes of low popularity may be a scalding sensation in the hand during intra‐arterial injection of lignocaine, which may be caused by low pH of lignocaine's solution.In this randomized, double‐blind study, normal (pH 5.2‐5.3) or alkalinized (pH 7.2‐7.3) preservative‐free 0.5% lignocaine 1.5 mg kg‐1 was injected into the radial arteries of forty adult patients to produce anaesthesia for ambulatory hand surgery.Scalding sensation in the hand during intra‐arterial injection (VAS) was less pronounced with alkalinized lignocaine (P=0.04). The time of onset and regression of analgesia was similar in both groups. Four patients in group 1 (normal lignocaine) and six patients in group 2 (alkalinized lignocaine) needed supplemental analgesia at the start of surgery (NS). Cannulation time, operating conditions, motor blockade, surgical‐, and tourniquet pain scores (VAS) and patient's acceptance were similar. Three patients (two in group 1 and one in group 2) had minor systemic adverse effects after tourniquet release (NS). Nine patients in group 1 and seven in group 2 developed minor bruises after cannulation (NS). No other sequelae of intra‐arterial injections were observed.We conclude that alkalinized 0.5% lignocaine was less painful on injection than normal lignocaine and should be preferred for intra‐arterial regional anaesthesia for hand surgery.