bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transoesophageal echocardiographic evaluation of ventricular function during transvenous defibrillator implantation
Authors: Poelaert J. , Jordaens L. , Visser C. A. , Clerck C. De , Herregods L. 
Published: January 2009

Background: Intraoperative testing and defibrillation threshold determination may jeopardise patients, scheduled for implantation of a cardioverter‐defibrillator (ICD). The purpose of this study was the assessment of the influence of consecutive defibrillation attempts on left ventricular systolic and diastolic function by means of transoesophageal echocardiography (TEE).Methods: Eighteen patients with malignant ventricular arrhythmias that were resistant to antiarrhythmic drugs were monitored with TEE before, during and after implantation of a cardioverter‐defibrillator. Left ventricular fractional area contraction as a measure of ejection fraction was assessed before and after each defibrillation attempt. Transmitral and right upper pulmonary venous flow parameters were evaluated before and after the whole implantation procedure.Results: Adequate data were available in 14 patients during 4 consecutive attempts. No major alterations were observed in heart rate or fractional area contraction, measured at 30 s and 3 min after defibrillation. Overall, the ratio of early‐to‐late transmitral filling decreased significantly after the implantation procedure (from 0.91±0.12 to 0.82±0.14; P<0.05). Systolic pulmonary venous flow velocity decreased from 0.49±0.11 to 0.41±0.10 m/s (P=0.04); this decrease was observed in both groups. A significant increase of the atrial contraction wave (from 0.25±0.06 to 0.34±0.07 m/s; P<0.03) was seen. Subdividing patients related to their preoperative ejection fraction, a significant decrease of the early‐to‐late transmitral filling of the LV was revealed in patients with ejection fraction less than 35% (group 1). Also, a significantly lower systolic fraction of the pulmonary venous flow after ICD implantation in conjunction with a significantly longer diastolic flow time was shown in this patient group in comparison with patients with a preoperative ejection fraction of more than 35% (group 2).Conclusion: Defibrillation threshold testing of the ICD system changes LV inflow characteristics and impedes diastolic function of the left ventricle and may thus precipitate heart failure by this mechanism. No deleterious effects of threshold testing were observed with respect to fractional area contraction nor any deterioration of LV function was found in a clinically significant amount due to consecutive defibrillation attempts.
Metabolic, ventilatory and circulatory effects of doxapram in anaesthetized pigs during normoxia and hypoxia
Authors: BjÖrk L. , Arborelius M. , Renck H. , Rosberg B. 
Published: January 2009

Background: In a previous clinical study doxapram was found to improve ventilatory efficacy postoperatively, presumably via effects on hypoxic pulmonary vasoconstriction (HPV). The present study was designed to see whether doxapram induced any changes of arterial oxygenation and pulmonary vascular resistance during normoxia or hypoxia and whether the changes were influenced by the anaesthetic agents.Methods: Seventeen piglets were anaesthetized by combinations of either midazolam + fentanyl + pancuronium + pentobarbital (TIVA, n = 9), or by midazolam + fentanyl + pancuronium + halothane, 0.5% in end‐tidal gas (Hal, n = 8). Analyses of expired gas and mixed venous and arterial blood in combination with determinations of central blood flow and pressures allowed for calculations of standard metabolic, ventilatory and circulatory data. Values were obtained at normoventilation using normoxic (FIO2 = 0.3) and hypoxic (FIO2 = 0.08) gas mixtures at calculated doxapram plasma concentrations of 1, 2 and 4 μg · ml‐1.Results: With few exceptions doxapram administration affected the investigated variables only moderately during normoxia. In group Hal, PVR and SVR showed a biphasic raise (P< 0.05), CO fell (P< 0.05‐P≥ 0.05) and C(a ‐v)O2 rose (P<0.05). In group TIVA, PaO2 fell (P<0.01‐0.05) despite unchanged PVR, CO and VD/VT. Hypoxia affected a moderate increase in PVR in group TIVA (P<0.05), which was slightly lower at the lowest and highest plasma levels of doxapram (P<0.05). In group Hal, the induction of hypoxia induced a more pronounced rise in PVR (P<0.05) which showed a biphasic response to increasing dose levels of doxapram, the lowest dose affecting a further rise (P<0.05) and the highest a reduction to values below hypoxia control levels (P<0.05). Pronounced differences between the two groups with respect to values for metabolic and circulatory variables make the interpretation of data difficult.Conclusions: Doxapram administration to anaesthetized animals did not induce any effects indicative of augmentation of the HPV response.
Postoperative seizure‐like activity following sevoflurane anesthesia
Authors: Terasako K. , Ishii S. 
Published: January 2009

Generalized clonic and tonic seizure‐like movements were observed during emergence from anesthesia with sevoflurane in a 32‐year‐old man.The movements lasted 40 sec and necessitated no therapy. There were no significant effects of the incident on the cardiovascular system, such as hypotension, arrhythmia or bradycardia.No neurological abnormalities were obvious after the anesthesia.The movements may have been the result of seizure activity in the central nervous system, or myoclonus of the whole body.
Effects of epidural analgesia on gastroduodenal motility Experimental and clinical studies with epidural morphine and epidural bupivacaine
Authors: Thorn S.‐E. 
Published: January 2009

Abstract: These investigations were undertaken to study the effects of epidural analgesia with morphine and bupivacaine on gastrointestinal motility and to evaluate if the effect of morphine after epidural administration is a central or peripheral effect. Comparative studies were performed in volunteers, postoperative patients and pigs. Gastroduodenal motility was evaluated by manometry, electromyography (EMG) and external electro‐gastrography (EGG). Gastric emptying was studied by an absorption test (acetaminophen) and orocecal transit time by the hydrogen breath test after ingestion of raffinose. In one study, intrathecal and intramuscular morphine were given simultaneously in an effort to receive plasma concentration of morphine comparable to that after an epidural administration. This combination was compared with intrathecal morphine alone to evaluate if the gastrointestinal effects were mediated by central or peripheral mechanisms.Epidural morphine delayed gastric emptying in healthy volunteers and in postoperative patients. Thoracic epidural bupivacaine with sensory block of the dermatomes T3‐T12 did not influence gastric emptying. Orocecal transit time was prolonged after epidural morphine compared to epidural bupivacaine. Duodenal contractile activity was significantly increased in volunteers after epidural morphine compared to epidural bupivacaine. The pressure activity seen after epidural morphine was not always propulsive and retrograde activity occurred frequently. Gastric activity measured by EMG and EGG was significantly disturbed after intrathecal and epidural morphine and tachygastria was frequently seen. Intramuscular administration of morphine during intrathecal morphine resulted in additive effects.These studies have shown that epidural morphine compared to epidural bupivacaine delays gastric emptying and prolongs orocecal transit time. These effects may be explained by the disturbed gastroduodenal motility seen after epidural morphine. The gastroduodenal effects of epidural morphine may be caused by both a central and a systemic effect of morphine.
Analgesia following arthroscopy — a comparison of intra‐articular morphine, pethidine and fentanyl
Authors: SODERLUND A. , WESTMAN L. , ERSMARK H. , ERIKSSON E. , VALENTIN A. , EKBLOM A. 
Published: January 2009

It has recently been reported that morphine given in low doses intra‐articularly can produce significant analgesia in patients undergoing arthroscopic knee joint surgery. Data are lacking on the effect of other opioids using a local approach for drug delivery.We studied the analgesic effect of intra‐articular opioids in 70 patients, divided into 7 groups, subjected to arthroscopic knee surgery in general anesthesia. The dimension of the study was based on a power of 0.8 to detect a 25% difference in pain intensity between those receiving opioids locally versus systemically (a=0.05 and β = 0.20). Following surgery, but before terminating anesthesia, the patients received one of the following combinations: 1 mg morphine intra‐articularly (i.art.) + saline intramuscularly (i.m.), 10 mg pethidine i.art + saline i.m., or 10 ug fentanyl i.art + saline i.m. In three additional groups the three opioids were given i.m. and saline given i.art. An additional control group received saline i.art. + i.m.We did not find any significant difference between the groups considering postoperative pain intensity, need for analgesics or considering time to standing/walking or to discharge, analysing each opioid independently. There was, however, a tendency for pethidine i.art. to produce the lowest pain scores both at rest and during movement (P= 0.06). If analysing the results with regards to if opioids were given intra‐articularly or systemically, not considering the type of opioid given, we did however, find a significantly lower total sum of pain scores at movement following local administration (P< 0.05). No specific side‐effects were detected. We conclude that pethidine given intra‐articularly merits further investigation with respect to postoperative analgesia following the activation of peripheral opioid mechanisms.
Long‐term intrathecal infusion of morphine in the home care of patients with advanced cancer
Authors: GESTIN Y. , VAINIO A. , PÉGURIER A. M. 
Published: January 2009

Background: Fear of infections and other complications has made many clinicians avoid intrathecal application of morphine in chronic cancer pain. However, recent comparative studies show that, in long‐term treatment, intrathecal morphine administration may give a more satisfactory pain relief with lower doses of morphine and fewer side‐effects than epidural administration. In Montpellier Cancer Institute, first cancer pain patients received long‐term intrathecal morphine as early as in 1979, and since then more than 400 patients have been treated.Methods: In 1991–1994, 50 patients having refractory cancer pain were treated with a continuous intrathecal infusion of morphine using an external pump with patient‐controlled boluses. In this retrospective study, the outcome of these 5602 days of morphine therapy will be analysed. The treatment consisted of a lateral puncture technique, strictly aseptic conditions during catheter insertion and changes of pump reservoirs, and effective prevention of side‐effects.Results: The average duration of intrathecal infusion was 142 (7–584) days. The mean starting dose, 2.5 (0.4–8.3) mg/day, increased to a mean final dose of 9.2 (1–94) mg/day, the average dose being 5.4 (1–23) mg/day. During the treatment period, no clinically detectable infections and no respiratory depression occurred. Leakage of cerebrospinal fluid followed by post‐spinal headache occurred in only 6 patients who received a temporary external catheter: the lateral lumbar puncture technique seemed to protect from this complication in long‐term treatment. The patients stayed at home, coming to agreed control visits only at 4–6‐week intervals, using a telephone‐telefax service for emergencies.Conclusions: Long‐term intrathecal morphine infusion seems to provide satisfactory analgesia, few side‐effects and a high degree of patient autonomy.
Epidural analgesia following upper abdominal surgery: United Kingdom practice
Authors: COOK T. M. , EATON J. M. , GOODWIN A. P. L. 
Published: January 2009

Background: Epidural Analgesia (EA) may be used to provide pain relief after upper abdominal surgery. A variety of drugs and combinations may be used. Potential side effects lead some to believe EA should be restricted to high care areas.Method: The use of EA following upper abdominal surgery is surveyed in 214 hospitals in the United Kingdom by means of a postal questionnaire.Results: Sixty‐seven percent use EA frequently and 3% not at all. The low thoracic site is the most commonly used, by 65%. Forty‐eight percent use a combination of sites. EA is most frequently achieved using a mixture of an opioid and a local anaesthetic (97%). No other agents are used. Fentanyl and diamorphine are the opioids used most widely (61% and 52% departments, respectively) in combination with local anaesthetic. Subcutaneous heparin is regularly used in 89% of departments. In 43%, the epidural is sited shortly after administering heparin. Use of EA is restricted solely to intensive or high‐care units in 46% of hospitals. In 82% of departments, EA is continued for up to 72 h. Ninety‐six percent of departments use continuous epidural infusions in the postoperative period. Adjunct analgesia includes non‐steroidal anti‐inflammatory drugs in 50% of departments. An anaesthetist supervises EA in 89% of hospitals. EA is considered to be the best mode of analgesia available by 80% of respondents.Conclusion: EA is widely used in the United Kingdom following upper abdominal surgery. A degree of consensus exists on the choice of drug types, their method of administration and duration. There is no consensus as to whether the technique should be used on a general ward, which opioid should be used or the timing of heparin.
Scintigraphic visualization of intrathecal liposome biodistribution
Authors: UMBRAIN V. , D'HAESE J. , ALAFANDY M. , DE ROOVER E. , SCHOUTENS A. , VAN GANSBEKE B. , ALBERT A. , GOFFINET G. , CAMU F. , LEGROS F. J. 
Published: January 2009

Background: Liposomes containing local anaesthetics have been administered intrathecally and in the epidural space. Poor attention has been given to the pharmacokinetics of liposomes as drug carriers. Therefore, we observed the biodistribution of liposomes after intrathecal injection in rats by scintigraphic imaging during 24 h.Methods: We administered 99Tc‐labeled multilamellar (MLV) and small unilamellar vesicles (SUV) of defined size and volume dispersities into the cerebrospinal fluid at the lumbar level. Those vesicles were free of contamination by radiolabeled colloids as visualized by light and electron microscopy and of neurotoxic products from phosphatidylcholine hydrolysis and peroxidation, both during the preparation process and after 24 h incubation in cerebrospinal fluid at 37°C in vitro.Results: SUV immediately diffused from the lumbar site of injection to the head and were cleared between 1 and 24 h after injection. MLV were cleared more slowly from the spinal space and appeared in the head region 1 h after injection where they accumulated up to 24 h. These differences were explained in terms of vesicle sizes and volumes. SUV with 0.05 μm diameters were rapidly absorbed into the blood through the arachnoid granulations. In contrast, particles larger than the upper size limit of the arachnoid granulations permeability (±8 μm) could accumulate in the head with a slow elimination rate.Conclusion: This difference in clearance from the intrathecal space outlines the importance of defining the size of the liposomes, the distribution of a tracer or a drug inside the liposomal preparation, the chemical stability and the absence of toxic degradation products of liposome formulations before clinical use.
Prevention of hypertension during trans‐sphenoidal surgery — the effect of bilateral maxillary nerve block with local anaesthetics
Authors: CHADHA R. , PADMANABHAN V. , ROUT A. , WAIKAR H. D. , MOHANDAS K. 
Published: January 2009

Background: Severe cardiovascular responses are known to occur during trans‐sphenoidal excision of the pituitary gland despite adequate depth of anaesthesia. This study was undertaken to evaluate the effects of bilateral maxillary nerve block with local anaesthetics on the cardiovascular responses to various stimuli during this procedure.Methods: In a group of 32 patients, 5–10 ml of a mixture of bupivacaine 0.5% and lignocaine 2% (1:1) was injected in the pterygopalatine fossa after induction of general anaesthesia. Seven control group patients did not receive any nerve block. In all the patients, general anaesthesia was induced with thiopentone and maintained with nitrous oxide‐oxygen, pentazocine, boluses of thiopentone and halothane. Pancuronium was used for neuromuscular blockade.Results: In both the groups, maximum hypertension occurred on opening the blades of the bivalve nasal speculum. In the study group, hypertensive response was signify cantly less following nasal infiltration with adrenaline containing solution (10.26% increase vs. 23.08% in the control group, P < 0.05), nasal dissection (2.82% vs. 9.45%, P < 0.01) and on application of the nasal speculum (14.93% vs. 35.16%, P < 0.01). The effect on heart rate response was not significant.Conclusion: The described technique is a useful adjunct to general anaesthesia for suppressing the haemodynamic responses during trans‐sphenoidal surgery.
Hemodynamic, sympathetic and angiotensin II responses to PEEP ventilation before and during administration of isoflurane
Authors: ANEMAN A. , PONTEN J. , FANDRIKS L. , EISENHOFER G. , FRIBERG P. , BIBER B. 
Published: January 2009

Background: Positive end‐expiratory pressure (PEEP) ventilation and isoflurane anesthesia may opposingly affect the sympathetic nervous and renin‐angiotensin systems. This study was performed to elucidate the modulatory effects of isoflurane anesthesia on the neurohumoral and cardiovascular responses to PEEP.Methods: Renin‐angiotensin and sympathetic nervous activity were investigated in mechanically ventilated, normovolemic, chloralose anesthetized pigs before and during administration of 1.4% isoflurane. Arterial angiotensin II (All) concentrations were measured and systemic, mesenteric, hepatic and renal spillover of norepinephrine (NE‐SO) were calculated using isotope dilution. Regional hemodynamic variables were investigated in parallel.Results: PEEP10 alone moderately elevated All levels (+12.5 ± 4.9 pg/ml, P < 0.05) and increased systemic (+22±2.9 pmolmin100g‐1, P < 0.05) and notably mesenteric (+32±9.6 pmolmin100g‐1, P < 0.05) NE‐SO. Blood flow decreased in all vascular beds studied. Except for in the liver, isoflurane generally reduced NE‐SO compared to baseline but did not change All concentrations. Strikingly, the sympathoexcitatory response to PEEP10 was inhibited, whereas All increased markedly (+284±64 pg/ml, P < 0.05) during PEEP10 and isoflurane. Renal blood flow was significantly more reduced during PEEP10 and isoflurane compared to PEEP10 alone, whereas the magnitude of reductions were similar in the other vascular beds.Conclusion: The data suggest that renin‐angiotensin activation is important to attenuate the impact of PEEP ventilation on cardioavascular performance during administration of the sympathodepressant isoflurane. Interference with the renin‐angiotensin system may cause cardiovascular decompensation in isoflurane anesthetized patients subjected to PEEP‐ventilation.
Effects of volatile anesthetics on the calcium ionophore A23187‐mediated alterations in hepatic flow and metabolism in the perfused liver in fasted rats
Authors: ARAKI M. , INABA H. , KON S. , IMAI M. , MIZUGUCHI T. 
Published: January 2009

Alterations in intracellular calcium homeostasis have been implicated in hepatic injury. Volatile anesthetics modulate the homeostasis of intracellular calcium.The effects of volatile anesthetics on the hemodynamic and metabolic alterations induced by the calcium ionophore A23187 were studied using isolated liver perfusion in fasted rats. The liver was isolated from 24 hr‐fasted male Sprague‐Dawley rats, and perfused through the portal vein at a constant pressure of 1.2 kPa in a recirculating perfusion‐aeration system. Halothane, isoflurane and sevoflurane were administered at 2%, 3% and 4.4%, respectively.All volatile anesthetics maintained basal hepatic flow, reduced oxygen consumption, and transiently enhanced net lactate production. A23187 at initial concentrations of 0.8 to 3.2 μM decreased hepatic flow and oxygen consumption in a dose‐de pendent manner, and enhanced lactate production. All anesthetics significantly attenuated the decreases in hepatic flow and oxygen consumption after administration of A23187 at 1.6 μM. None of the anesthetics significantly influenced the A23187‐induced enhancement of net lactate production.Volatile anesthetics may attenuate the hepatic vasoconstriction and oxygen debt induced by intracellular calcium overload.
A comparison of pressure‐ and volume‐controlled ventilation at different inspiratory to expiratory ratios*
Authors: LUDWIGS U. , KLINGSTEDT C. , BAEHRENDTZ S. , HEDENSTIERNA G. 
Published: January 2009

Background: Inverse ratio ventilation (IRV) is frequently used in severe acute respiratory failure. IRV may lead to intrinsic positive end‐expiratory pressure (PEEP) and is thought to improve oxygenation and to have advantageous effects on lung mechanics. Published data to support the use of IRV are scarce. This animal study compares external PEEP with intrinsic PEEP in pressure‐ and volume‐controlled ventilation.Methods: Fifteen pigs were randomly treated with 1. volume‐controlled PEEP ventilation (I:E ratio 1:2) (VCV PEEP), 2. volume‐controlled ventilation (I:E ratio 4:1) (VCIRV) and 3. pressure‐controlled ventilation (I:E ratio 4:1) (PCIRV). Baseline measurements were performed using volume‐controlled ventilation (I:E ratio 1:2) (VCV ZEEP). Lung mechanics, haemo‐dynamics and gas exchange were measured by standard methods and functional residual capacity (FRC) by the sulphur hexafluoride technique.Results: In comparison to VCV PEEP, PCIRV resulted in reduced peak airway pressure (32±3 vs. 27±6 cm H2O, P < 0.001) and increased mean airway pressure (14±2 vs. 22±5 cm H2O, P < 0.001). FRC was 942±264 ml in VCV PEEP and 1024±390 ml in PCIRV (n.s.). Oxygen delivery was lower in PCIRV (458±193 vs. 346±150 ml/min, P < 0.05). Physiologic dead space was 14±4% in PCIRV and 20±6% in VCV PEEP and VCIRV (P < 0.005).Conclusions: Inverse ratio ventilation did not result in improved FRC in comparison to conventional volume‐controlled PEEP ventilation. PCIRV allows for a reduction in minute ventilation but the increase in mean airway pressure compromises circulation.