bluuebunny/crossref_metadata_2025 huggingface dataset:
Flumazenil facilitates intraoperative arousal during scoliosis surgery: a randomized, doubleblind, placebo‐controlled study
Authors: KOSCIELNIAK‐NIELSEN Z. J. , SCHIERBECK J. , PEDERSEN H. L. STENS , PERKO G.
Published: January 2009

Intraoperative arousal was evaluated in 24 patients (median age 16.5 years), undergoing spondylodesis with Cotrel–Dubousset or Harrington–Luque instrumentation. Flumazenil and placebo groups of 12 patients each were similar with respect to age, body weight, dosage of anaesthetic drugs and surgery times. Premedication consisted of diazepam 0.2–0.3 mg kg‐1 orally. Anaesthesia was induced with thiopentone 5–7 mg kg‐1, and maintained with 66% nitrous oxide in oxygen, and repeated doses of fentanyl, midazolam and atracurium. After placement and fixation of the metal rods, N2O was switched off, and either flumazenil or placebo was given in refracted doses until the patient responded to command. Intraoperative motor response times (medians with ranges), defined as the time from the injection of the first dose until the patient responded to command, were 2.5 min (1.0–5.2 min) after flumazenil, and 8.0 min (1.7–28.5 min) after placebo (P = 0.02). Five patients in the placebo group did not wake up within 10 min and received naloxone. The quality of awakening was similar in both groups. Two patients (one in each group) woke up violently and needed physical restraint. Postoperatively, motor responses were assessed after 12.0 min (5–42 min) in the flumazenil group, and after 15.2 min (4–40 min) in the placebo group (NS). Recovery from anaesthesia took 27.5 min (7–415 min) in the flumazenil group, and 25.0 min (8–160 min) in the placebo group (NS). One patient given flumazenil and one patient given placebo remembered moving their feet, but neither of them could recall anything unpleasant. It is concluded that flumazenil significantly shortens the time of intraoperative arousal during scoliosis surgery under midazolam, N2O/O2 anaesthesia, without having to compromise the analgesia provided by fentanyl. Flumazenil does not facilitate postoperative motor testing or recovery, nor does it affect recall of the intraoperative events.
Effects of ephedrine and phenylephrine on maternal and fetal atrial natriuretic peptide levels during elective cesarean section
Authors: PIERCE E. T. , CARR D. B. , DATTA S.
Published: January 2009

The effects of ephedrine and phenylephrine on fetal and maternal plasma atrial natriuretic peptide (ANP) concentrations were studied during 30 elective cesarean sections. After induction of spinal anesthesia, reductions from baseline maternal blood pressure were corrected with one of these pressor agents administered in a double–blinded, randomized manner. Immediately following delivery, umbilical artery (UA) ANP concentrations were significantly higher than umbilical vein (UV) concentrations (pg/ml) for both groups (ephedrine, 120.8±64.0 vs. 86.8±40.8, phenylephrine, 125.0±54.2 vs. 72.4±31.7), but there were no differences between groups for UA and UV ANP levels. Postpartum maternal ANP concentrations were significantly higher than baseline values in both groups, but again there were no differences between groups. Correlations between total doses of ephedrine or phenylephrine and UA or UV ANP levels did not reach significance. Postpartum maternal (MV2), UA, and UV blood gas variables (pH, Pco2, and Po2) were also not different between groups. These data suggest that effects of pressor doses of ephedrine (beta and alpha agonist) and phenylephrine (alpha agonist) on maternal and fetal ANP levels are not different. Therefore, 1) assuming these pressor drugs stimulate ANP release, this stimulation is not solely mediated by beta receptors and 2) to the extent that fetal ANP influences feto–placental circulatory homeostasis, the effects of ephedrine and phenylephrine on this regulatory mechanism do not appear to be different.
Effects of epidural morphine and epiduralo bupivacaine on gastroduodenal motility during the fasted state and after food intake
Authors: THÖRN S.–E. , WATTWIL M. , KÄLLANDER A.
Published: January 2009

The effects of a thoracic epidural analgesia with morphine or bupivacaine on gastroduodenal motility during the fasted state and after food intake were evaluated in healthy volunteers. Nine volunteers were studied on two occasions, separated by at least 2 weeks, and were randomly allocated to receive either epidural morphine or epidural bupivacaine at the T6–T7 level on each occasion. Gastroduodenal motility was measured by manometry. Acetaminophen absorption was used as an indirect measure of the rate of gastric emptying and orocecal transit time was determined by use of the hydrogen breath test after ingestion of raffinose. During the control measurements, before the epidural analgesia, there were no differences in gastroduodenal pressure activity between the morphine and bupivacaine groups. Compared to epidural bupivacaine, epidural morphine significantly changed the pressure activity with a higher number of contractions in the duodenum, both during the fasted state and after food intake. Retrograde pressure activity was seen in the duodenum after epidural morphine but not after epidural bupivacaine. There were no significant differences in the pressure activity in the stomach after epidural morphine compared to epidural bupivacaine. Gastric emptying was delayed and orocecal transit time prolonged after epidural morphine. This study in volunteers showed that epidural morphine, compared to epidural bupivacaine, significantly changed the gastroduodenal motility, both during the fasted state and after food intake.
Importance of modes of acupuncture in the treatment of chronic nociceptive low back pain
Authors: THOMAS M. , LUNDBERG T.
Published: January 2009

A controlled study of different modes of acupuncture stimulation was conducted on patients fulfilling clinical criteria for chronic low back pain of nociceptive origin. Forty patients were randomly entered into the study. Thirty had three trial treatments with manual stimulation of needles (MS), electrical low frequency stimulation at 2 Hz (LF), and high–frequency stimulation at 80 Hz (HF), and then continued treatment with the mode they felt most benefitted them. Ten patients were put on the waiting list for treatment but served as the untreated control group. The results were evaluated after 6 weeks and at 6 months for: activity related to pain; mobility; verbal descriptors of pain and the patient's subjective assessment of his condition. After 6 weeks, patients receiving treatment showed significant improvement (P < 0.05 to P < 0.001) on three of the four measures compared to the untreated controls. After 6 months a similar measure of significant improvement was seen in patients continuing with low–frequency (LF) acupuncture, but not in those groups continuing with manual stimulation (MS) or high–frequency (HF) acupunture. The results suggest that 2 Hz electrical stimulation is the mode of choice when using acupuncture in the treatment of chronic nociceptive low back pain.
Attenuation of arterial baroreflex control of renal sympathetic nerve activity during lidocaine infusion in alpha–chloralose–anesthetized dogso
Authors: YONEDA I. , NISHIZAWA M. , BENSON K. T. , CHAFFEE T. L. , GOTO H.
Published: January 2009

The purpose of this study was to identify the relationship between sensitivity of arterial baroreflex and plasma concentrations of lidocaine. Using twelve mongrel dogs anesthetized with alpha–chloralose, the left kidney was exposed retroperitoneally, and renal sympathetic nerve activity was recorded continuously. Lidocaine was infused in four different doses: 2 mg– kg BW‐1 bolus + 100 μg– BW‐1. min; 3 mg– kg BW‐1 bolus+ 200 μg–kg BW‐1min; 6 mg–kg BW‐1 bolus+ 400 μg–kg BW‐1min; and 12 mg–kg BW‐1+ 800 μg–kg BW‐1min. Baroreflex depressor and pressor tests using sodium nitroprusside (5–10 μg–kg‐1) and phenylephrine (2–4 μg–kg‐1) were performed before and at 10 min after beginning lidocaine infusion. Plasma lidocaine concentrations determined by high performance liquid chromatography revealed that the steady–state levels were maintained during the baroreflex tests. Baroreflex sensitivity was preserved at plasma concentrations of lidocaine below 5 μg. ml‐1. However, cardiac and sympathetic baroreflex sensitivity were significantly attenuated (P < 0.01) when plasma lidocaine concentrations were well above human convulsion levels (10μg–ml‐1). The results indicate that hemodynamic derangement observed in the lidocaine–induced central nervous system toxicity is, at least in part, due to the attenuated arterial baroreflex.
Adenosine protects ultrastrueture of isolated rat lungs against fat emulsion injury
Authors: JOLIN Å. , MYKLEBUST R. , OLSEN R. , BJERTNAES L. J.
Published: January 2009

In isolated rat lungs subjected to fat emulsion damage, a model simulating adult respiratory distress syndrome, we have previously reported that adenosine (ADO) reduces pulmonary vascular resistance (PVR) and the fluid filtration rate (FFR). In the present study the aim was to examine morphologically this effect of ADO. Two groups of isolated rat lungs were subjected to the injury. Marked and significant differences were found between the groups; in lungs not given ADO, FFR and airway pressure were higher and, as evaluated by electron microscopy, the endothelial lining was thin and partly disrupted. The epithelial cells of the alveolar walls were also partly disrupted and the alveolar septa were split enclosing interstitial edema. In lungs receiving ADO from the onset of exposure to fat emulsion, FFR was lower and ultrastructure did not differ from non–injured non–treated controls perfused for the same length of time.
Anaesthetic agents and excretion in breast milk
Authors: SPIGSET O.
Published: January 2009

This review is an update on anaesthetic agents and their excretion into breast milk; it presents the reported effects on suckling infants, and discusses the precautions which should be considered. For most anaesthetic agents, there is very sparse information about breast milk excretion and even less published knowledge about the possible effects on the suckling infant. Generally, when an anaesthetic agent is given on a single–dose basis, there is no evidence that it is excreted in breast milk in clinically significant amounts, even if there are detectable concentrations of the drug in the milk. Most anaesthetics are rapidly cleared from the mother, and, consequently, it should be possible to allow suckling as soon as practically feasible after surgery. However, repeated administration of certain opiates and benzodiazepines has been reported to cause adverse effects in neonates, with premature neonates apparently being more susceptible. Thus, in long–term treatment with these drugs, the importance of uninterrupted breast feeding should be assessed against possible adverse drug effects in the neonate.
Effect of hypertonic NaCl–starch–solution on oedema of different pathogenesis
Authors: KOCH T. , NEUHOF H. , KOHLER P. , DUNGKER H. P. , BUSE A. , VAN ACKERN K.
Published: January 2009

Small volumes of hypertonic NaCl–solutions have been proven to restore haemodynamics in hypovolemic shock patients. Topic of this study was to investigate whether bolus application of 7.5% NaCl–6.5% starch–solution (HSS) apart from its relevance in shock might be an effective therapy in oedema. Considering differential therapeutic aspects, the volume effects of 7.2 ml HSS were tested in three types of oedema: hydrostatic oedema induced by venous congestion (n = 6), oedema caused by bradykinin injection (n = 6), and proteinase–induced oedema (n = 6). The arterial, venous pressure and weight changes indicating volume shifts between intra– and extravascular space were continuously monitored in 36 isolated perfused rabbit hindlimbs. Oedema formation was induced corresponding to a weight gain of 18–20 g. Subsequently 7.2 ml HSS were injected into the extracorporeal circulation system containing 200 ml cell free, isoosmotic perfusate. Six experiments of each oedema group without HSS–application served as controls. 75–100% of oedema formation could be remobilised via bolus application of HSS within 5 min in all types of oedema. A persisting weight reduction was detectable in the hydrostatic and bradykinin oedema, whereas in the elastase oedema the initial weight loss was followed by a regain of weight up to 180% of initial oedema formation at 120 min after HSS–application. The results show that, due to the osmotic gradient induced by bolus application of HSS, the hydrostatic and bradykinin oedema can be permanently remobilised, whereas the therapeutic effect during proteinase oedema is only short–lasting due to an irreversible damage of barrier function.
Propofol vs isoflurane for gynaecological laparoscopy
Authors: OlKKONEN M.
Published: January 2009

Propofol (n= 15) and isoflurane (n= 15), both administered by clinical and haemodynamic criteria, proved to be equally feasible as sole maintenance anaesthetics (combined with 0.5 mg alfentanil and suxamethonium) for gynaecologic laparoscopics. Two min postextubation, the number of patients awake and responsive to commands was higher in the group given propofol. Later recovery till 2 h postanaesthesia was similar for the groups, except that the propofol patients more frequently required oxycodone for pain relief, and that three of them (NS) were bradycardic. Emesis was rare in both groups. The rapid recovery without emesis qualifies these two anaesthetics for gynaecologic laparoscopics.
Effects of intravenous lidocaine on cardiac sympathetic nerve activity and A–V conduction in halothane–anesthetized cats
Authors: NISHIKAWA K. , TERAI T. , MORIMOTO O. , YUKIOKA H. , FUJIMORI M.
Published: January 2009

To study neural contributions to the alterations in intracardiac conduction induced by IV lidocaine, we measured cardiac sympathetic nerve activity (CSNA) simultaneously with sinus cycle length (SCL) and AV conduction time using His–bundle electrocardiography following IV lidocaine in cats. Sixteen cats were anesthetized with halothane in oxygen and mid–sternotomized. The His–bundle electrogram and CSNA were recorded from an electrode placed in the interatrial septum and from the left ventrolateral or ventromedial nerve, respectively. Atrium–His (A–H), His–Purkinje (H–V), and total intraventricular (H–S) conduction times were measured during atrial pacing conducted at a cycle length of 300 ms. In eight cats, 1 MAC, 2 MAC, and 3 MAC halothane were given during IV lidocaine (Groups H–l, H–2 and H–3). In the other eight cats, anesthesia was switched from halothane to IV alpha–chloralose (30–50 mg–kgBW‐1; Group C). A significant decrease in CSNA with IV lidocaine, 2 mg–kgBW‐1′ was recognized in Groups C and H–l, but not in Groups H–2 and H–3. Prolongations of SCL during the spontaneous cycle, A–H and H–V in the paced mode following IV lidocaine were significant in Groups C, H–l and H–2, but not significant in Group H–3. We conclude that IV lidocaine induces a significant decrease in CSNA during alpha–chloralose or 1 MAC halothane anesthesia which partly contributes to the control of intracardiac conduction.
Clinical experience with minimal flow xenon anesthesia
Authors: LUTTROPP H. H. , THOMASSON R. , DAHM S. , PERSSON J. , WERNER O.
Published: January 2009

Xenon is a more potent anesthetic than nitrous oxide, and gives more profound analgesia. This investigation was performed to assess the potential of xenon for becoming an anesthetic inspite of its high manufacturing cost. Seven ASA I—‐II patients undergoing cholecystectomy (n = 4), hernia repair (n = 2), or mammoplasty (n=l) were studied. Denitrogenation by 15–20 min of oxygen breathing under propofol anesthesia was followed by fentanyl–supplemented xenon anesthesia administered via an automatic minimal flow system which held the oxygen concentration at 30%. Xenon anesthesia lasted 76–228 min and 8–14 1 of xenon (ATPD) was used, of which 5.6–8.1 1 was expended during the first 15 min. Anesthesia appeared to be satisfactory, and the patients woke up rapidly after xenon was discontinued. The automatic system made minimal flow xenon anesthesia easy to administer, but nitrogen accumulation is still a problem. Assuming a xenon price of 10 US $ per litre, the average cost for xenon was about 65 US $ for the first 15 min and then about 25 USS for each subsequent hour of anesthesia.
Measurement of dead–space in a model lung using an oscillating inspired argon signal
Authors: WILLIAMS E. M. , GAVAGHAN D. J. , OAKLEY P. A. , SAINSBURY M. C. , XIONG L. , BLACK A. M. S. , HAHN C. E. W.
Published: January 2009

In a model lung, airways dead–space can be accurately measured using a forced inspired oscillating argon signal, which varies sinusoidally about a mean concentration of 6% v/v with an amplitude of ± 4% v/v. With sinusoid forcing periods longer than 120 seconds, and at a breathing rate of 13.4 breaths minute‐1, the mean airways dead–space can be measured with a standard error of less than 5%. Sinusoid forcing periods shorter than 120 s provided inaccurate estimates of dead–space and so should not be used with this technique.
Effects of metabolic pH–alterations on cerebral blood flow and oxygen uptake following E. coli endotoxin in dogs
Authors: WESTERLIND A. , LARSSON L. E. , HÄGGENDAL J. , EKSTRÖM–JODAL B.
Published: January 2009

The aim of the present study was to investigate if metabolic pH–alterations have an influence on cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRo2) after an injection of E. coli endotoxin. Following endotoxin in dogs with normal pH a decreased CBF and an increased CMRo2 have earlier been found. Thirteen anaesthetized dogs were subjected to metabolic pH–variations in blood by infusion of hydrochloric acid or sodium bicarbonate. Ten dogs received E. coli endotoxin in a dose of 1 mg kg“‘ bodyweight. CBF, CMRo2 and noradrenaline and adrenaline concentrations in blood and cerebrospinal fluid were measured repeatedly during normoxia and normocarbia. Measurements before endotoxin served as controls, together with three additional animals, where endotoxin was never given. In control measurements pH showed no influence on the variables studied. After endotoxin CBF, CMRo2 and noradrenaline in cerebrospinal fluid increased with decreasing arterial blood pH. The influence exerted by metabolic pH alterations in blood after endotoxin may be explained by hydrogen ions and monoamines passing over a blood–brain barrier (BBB), damaged by endotoxin, into the brain tissue causing vasodilation and neuronal activation.
Poikilocapnic hypoxic ventilatory response in humans during 0.85 MAC isoflurane anesthesia
Authors: SJOGREN D. , SOLLEVI A. , EBBERYD A. , LINDAHL S. G. E.
Published: January 2009

Ventilatory responses to hypoxia (HVR) were investigated using poikilocapnic conditions (i.e. end–tidal CO2′s allowed to seek it's own level) in 15 cardio–pulmonary healthy patients who were first studied awake and then at 0.85 MAC isoflurane. The influence of hypercapnia (HyperCapnic Ventilatory Response, HCVR) was also elucidated. Pneumotachography, capnography and airway occlusion pressures at 0.1 s (P < u) were used before and during both mild hypoxia (end–tidal O2 tension 8.7 kPa) and hypercapnia achieved by an inspired CO2 concentration of 5%. HCVR was attenuated by 60% during anesthesia (P < 0.01). In the awake state, five of the 15 patients decreased HVR during hypoxia as compared with during normoxia. This resulted in a VE that on average increased by 0.6 l–min‐1 (P < 0.05) whereas PE01 was unchanged. In the anesthetized state, no case of decreased HVR was seen and hypoxia induced a mean VE increase (±s.d.) by 1.0± 0.2 lmin‐1 (P< 0.001) and a PE01 that on average was improved by 0.63 ± 0.27 cm H2O (P< 0.01). It is suggested that when the aim is to evaluate the influence of volatile anesthetic agents on HVR and to quantitate its clinical relevance during and immediately after anesthesia, a poikilocapnic technique should be used. It is concluded that the poikilocapnic HVR to PF.o2′s of 8.7 kPa was maintained during 0.85 MAC isoflurane.
Alfentanil or fentanyl during isoflurane–based anaesthesia for day–care knee arthroscopy?
Authors: GUPTA A. , VEGFORS M. , ODENSTEN M. , LENNMARKEN C.
Published: January 2009

Forty patients agreed to participate in a study to compare whether fentanyl or alfentanil used as analgesic is associated with quicker recovery following anaesthesia for outpatient arthroscopy procedure. Psychomotor tests including choice reaction time (CRT), perceptive accuracy test (PAT) and finger tapping test (FTT) were done prior to induction of anaesthesia with propofol (2–3 mg–kg‐1). Patients were then divided into two groups: Group F (fentanyl) received 0.1 mg fentanyl prior to start of surgery and thereafter 0.05 mg every 30 min during the procedure. Group A (alfentanil) received 0.5 mg alfentanil prior to the onset of surgery and 0.25 mg every 15 min thereafter. Anaesthesia was then maintained using isoflurane (0.5–2%) in oxygen and air (Fio2 0.33) during spontaneous respiration with a face mask in a Bain's system. Psychomotor tests were repeated every 45 min postoperatively. Clinical recovery, visual analogue pain intensity score (VAS) and time to discharge home were also assessed by a nurse blind to the method used. Patients in Group A returned to baseline values on the FTT after 90 min while those in Group F did not return to baseline values until 135 min after the end of the operation. Clinical recovery and time to discharge home (“home ready”) were also significantly longer in Group F. There was no difference in recovery as seen in the PAT and CRT between the groups. Also, there was no difference in the incidence of side effects and the pain intensity (VAS) scores were similar in the two groups at all time periods. We conclude that recovery following alfentanil is quicker compared to fentanyl when anaesthesia is based on isoflurane.
Morphine does not affect laser induced warmth and pin prick pain thresholds
Authors: VAN DER BURGHT M. , RASMUSSEN S. ELKJÆR , ARENDT–NlELSEN L. , BJERRING P.
Published: January 2009

The aim of this double–blind, placebo–controlled study was to evaluate the effect of intravenously administered morphine in humans using an argon laser to induce experimental pain. Thirty volunteers were randomised to receive a total of 0.15 mg. kg‐1morphine intravenously or saline. The argon laser was used to determine the possible change in warmth thresholds and pin prick pain thresholds. Measurements were performed before and at 10, 20, 30 and 40 min after the injection. During the observation period the warmth thresholds increased 20.7% (P≤ 0.05) from baseline (0.82 W ± 0.42 W) in the morphine group while an increase of 14.3% (P≤ 0.05) was seen in the placebo group (Baseline: 0.91 ±0.37). The pinprick pain thresholds of the morphine group increased 9.4% (P≥ 0.05) from baseline (1.39 W ± 0.7 W) while the corresponding thresholds of the placebo group was 4.6% (P> 0.05) (baseline: 1.73 W±0.44 W). The differences seen between the morphine group and the placebo group were not statistically significant and thus it was demonstrated that morphine had no effect of either the feeling of warmth or the pain elicited by the argon laser. The present study supports other investigations and clinical experience suggesting that intermittent pain is not relieved by morphine unlike continuous pain, which can be relieved by morphine.
The effects of regional anaesthesia for caesarean section on maternal and fetal blood flow velocities measured by doppler ultrasound
Authors: VALLI J. , PIRHONEN J. , AANTAA R. , ERKKOLA R. , KANTO J.
Published: January 2009

We studied the effects of spinal anaesthesia (Group S), epidural anaesthesia (Group E), and combined spinal and epidural anaesthesia (Group SE), on maternal and fetal blood flow in 24 healthy parturients (n = 8/group) with uncomplicated singleton pregnancies using Doppler technique. Prior to the induction of anaesthesia, the patients were prehydrated with balanced electrolyte solution 15 ml kg‐1 over a period of 15 min. After the induction of regional anaesthesia, the systolic blood pressure was maintained within 15% limits of the preoperative values using prophylactic etilefrine infusion in Groups S and SE. The flow velocity waveforms of the maternal femoral artery, the main branch of the uterine artery (placental side), the foetal umbilical and middle cerebral arteries were recorded by Doppler technique before and after prehydration as well as after onset of T7 analgesia and the pulsatility indices (PI) were derived. Rapid intravenous prehydration had no effects on uteroplacental or fetal circulation as indicated by unaltered uterine, umbilical, and fetal middle cerebral artery Pis. After the onset of T7 analgesia, the uterine artery PI was increased in Group S indicating increased uterine vascular resistance while no changes occurred in Groups E and SE. No adverse effects were observed on the neonates as indicated by the Apgar score and the umbilical artery and vein acid–base status in any of the groups.
NBQX (2, 3–dihydroxy–6–nitro–7–sulfamoyl–benzo(F)quinoxaline) did not affect recovery of high energy phosphates and pH in early reperfusion in a rat model of transient forebrain ischemia, or:An in vivo31PNMR spectroscopy study
Authors: MÜLLER T. B. , HARALDSETH O. , SONNEWALD U. , UNSGÅRD G. , PETERSEN S. B.
Published: January 2009

The new non–NMDA (N–methyl–D–aspartate) receptor antagonist NBQX (2, 3–dihydroxy–6–nitro–7–sulfamoyl–benzo(F)quinoxaline) has previously been shown to exert a neuroprotective effect in animal models of cerebral ischemia when administered in the post–ischemic phase. In this investigation the effect of NBQX on acidosis and energy recovery in early reperfusion after 10 min of transient forebrain ischemia with the 2–vessel occlusion model in the rat was studied with 31P NMR spectroscopy. In the intervention group the animals received a bolus dose of NBQX 30 mg kg‐1 iv at the start of reperfusion. 31P NMR spectroscopy was used to measure intracellular pH, ATP and phosphocreatine continuously in–vivo during, and after, the ischemic event. The recovery of high energy phosphates and pH was followed during 30 min of reperfusion. Pre–ischemic levels of phosphocreatine were reached after approximately 9–10 min in both groups. Although a slight improvement could be seen in the intervention group there was no significant difference in the rate of recovery between the two groups. ATP reached 90% of preischemic levels after about 8 min without significant difference between the two groups. With respect to the recovery of intracellular pH, no difference could be shown. Our results do not contradict previously published results, but suggest that the potential protective effect of NBQX is not mediated through improved recovery of energy metabolism in early reperfusion.
Selective positive end–expiratory pressure and right ventricular function in dogs
Authors: VEDDENG O. J. , RISØE C. , RIDDERVOLD F. , SMISETH O. A.
Published: January 2009

Differential ventilation with selective positive end–expiratory pressure (PEEP) has been shown to reduce cardiac output less than general PEEP. In previous studies we have demonstrated that during selective PEEP left ventricular preload is better maintained than during general PEEP. The present study was designed to determine whether the different haemodynamic responses to selective and general PEEP also might be due to different effects on RV preload. The study was performed on nine acutely instrumented dogs, in which extraventricular pressure was measured by pericardial balloon transducers. Measures of RV preload were obtained by the use of ultrasonic segment length transducers as well as end–diastolic transmural pressure (RVEDPTM). The study showed reductions in RVEDP TM during general and selective right (R) PEEP, accompanied by moderate reductions in RV inflow tract segment lengths. These changes were most marked with general PEEP. Selective LPEEP did not change RV preload significantly. Therefore, better maintained cardiac output with selective PEEP than with general PEEP is partly due to less impairment of right ventricular filling.
Central and regional blood flow during hyperventilation
Authors: KARLSSON T. , STJERNSTRÖM E–L. , STJERNSTRÖM H. , NORLÉN K. , WIKLUND L.
Published: January 2009

Mechanical hyperventilation not only reduces brain oedema after neurotrauma but also affects the central and systemic circulation. We have, in pigs, measured blood flow in the pulmonary artery, the portal vein and in the femoral artery, as well as estimated the splanchnic blood flow and studied the relative perfusion using the microsphere technique in normo– and hypocarbia during intermittent positive pressure ventilation. A normoventilated control group did not change in cardiac output, portal vein blood flow, splanchnic blood flow and femoral arterial blood flow. Hyperventilation was performed to a Pco2 of 3.0± 0.1 kPa. We found that in pigs ventilated with high tidal volume skeletal muscle blood flow did not change during the first 60 min of hyperventilation but gradually decreased thereafter. Blood flow to the cerebellum decreased soon after the induction of hyperventilation, whereas the cerebral blood flow did not decrease until the second hour of hyperventilation. Cardiac output, splanchnic perfusion and portal vein blood flow all decreased. Myocardial perfusion and arterial blood flow to spleen and kidney decreased while pancreatic and liver arterial blood flows were unaffected. It is concluded that mechanical hyperventilation with low frequency and large tidal volumes reduces the flow to most tissues, where the relative decrease according to microsphere measurements is most pronounced in skeletal muscles, heart muscle and cerebellum. However, the changes in cardiac output and splanchnic blood flow were not observed when hyperventilation was induced by increased frequency, keeping the tidal volume constant.
Right ventricular end–systolic pressure–volume relation during propofol infusion
Authors: MARTIN C. , PERRIN G. , SAUX P. , PAPAZIAN L. , ALBANESE J. , GOUIN F.
Published: January 2009

The effects of propofol on right ventricular function were studied in 11 ICU patients who needed sedation for acute respiratory failure or neurological diseases. Right ventricular function was studied using a thermodilution method at patients' bedside. Right ventricular ejection fraction (RVEF), cardiac output (CO), right ventricular end–diastolic volume (RVEDV), right ventricular end–systolic volume (RVESV), right ventricular end–systolic pressure (RVESP) and pulmonary capillary wedge pressure (PCWP) were obtained from a modified Swan–Ganz catheter. Calculation of right ventricular end–systolic pressure–volume relation (ESPVR) allowed to assess changes in right ventricular inotropic state. A baseline ESPVR was obtained before propofol infusion: RVESP = 0.21 RVESV + 2.4, r = 0.83, P < 0.0001. Then, patients were given an induction dose of 1 to 2.5 mg kg‐1 propofol over 1 min followed by a continuous infusion of 3 mg kg‐1 h‐1. During propofol infusion heart rate, mean arterial pressure, PCWP, CO, systemic vascular resistance and RVEF significantly decreased. No change in RVEDV and RVESV was observed. ESPVR was significantly altered with a dramatic decrease in the slope of the relation: RVESP = 0.12 RVESV + 6.9 (P < 0.001 from baseline). Dobutamine was used in five patients with clinically significantly cardiac dysfunction and restored the slope of the ESPVR to the baseline value: RVESP = 0.22 RVESV + 6.3 (NS from baseline). In the study patients, propofol altered the inotropic state of the right ventricle.
The effect of position and different manoeuvres on internal jugular vein diameter size
Authors: ARMSTRONG P. J. , SUTHERLAND R. , SCOTT D. H. T.
Published: January 2009

Internal jugular vein (IJV) cannulation is a popular approach for central venous access as it has few complications, of which failure to locate the vein and carotid artery puncture are the most common. A variety of manoeuvres and body positioning has been used to maximise IJV size and thereby increase cannulation success rate and decrease complications. Realtime 2D ultrasound can be used to view neck vascular anatomy in vivo and allow IJV size to be measured. Thirty–five volunteers had the lateral diameter of their IJV measured using the SiteRite ultrasound machine to discover the most effective methods of increasing its diameter. No correlation was found between the IJV lateral diameter and subject height, weight, age or neck circumference. Carotid artery palpation and full neck extension reduced its diameter considerably. Increasing Trendelenberg increased diameter. Abdominal binder and the Valsalva manoeuvre were the most efficient methods of increasing its size.
Intraoperative measurement of activated partial thromboplastin time and prothrombin time with a new compact monitor
Authors: SAMAMA CHM. , QUEZADA R. , RIOU B. , MOURGEON E. , AROCK M. , ANKRI A. , VIARS P.
Published: January 2009

A prospective study was conducted to evaluate a new compact portable coagulation monitor (Ciba–Corning Biotrack 512 Monitor), which enables the clinician to perform instantaneous activated partial thromboplastin time (APTT) and prothrombin time (PT). 126 patients scheduled for heparinized and nonheparinized vascular surgery, and gynaecological surgery, were included. A drop of capillary or venous whole blood was applied in disposable cartridges to successively perform APTT and PT, and the results of the tests were compared with conventional laboratory methods, performed in two different laboratories (Lab. A and B). Comparisons between Lab. A. and Lab. B. enables determination of the bias, precision, and percent of outliers (patients whose values differed more than 20%) in conventional methods. The reference value was defined as the mean of Lab. A. and Lab. B. values. For PT, there were no statistical differences between the capillary and venous samples performed with the portable monitor, and the reference value, for the bias, the precision and the proportion of outliers. For APTT, there were no statistical differences between the capillary and venous samples performed with the portable monitor, and the reference value, for the bias and the precision. The percent of outliers, however, was significantly greater with the venous sample of the compact monitor than with the reference (48 versus 22%), and even if it did not reach the statistical significance (P = 0.07) it was also higher with the capillary sample performed with the Ciba Monitor than with the reference (33%). In conclusion the assessment of blood coagulation using this new compact monitor could be of major interest during the intraoperative period when immediate results are mandatory, even if PT is more accurate than APTT with this new method.
Midazolam/propofol but not propofol alone reversibly depress the swallowing reflex
Authors: D'HONNEUR G. , RIMANIOL J. M. , SAYED A. EL , LAMBERT Y. , DUVALDESTIN P.
Published: January 2009

General anaesthetics depress swallowing and this is a reason to delay oral intake after general anaesthesia. The swallowing reflex was studied 2 h after general anaesthesia for patients undergoing colonoscopy. Forty–one patients were anaesthetized with midazolam 75 μgkg‐1 followed by a continuous infusion of propofol and 39 patients with propofol 1.5 mgkg‐1 bolus followed by an infusion. Swallowing reflex was measured by electromyography 2 h after induction of anaesthesia, before and 5 min after the administration of flumazenil (0.2 mg) or placebo. Two h after anaesthesia, the state of consciousness was almost normal in all patients and did not change after flumazenil. At two hours, the latency times for the swallowing reflex in patients treated with propofol alone were of 1.4 ± 0.4 s and were significantly shorter (P < 0.05) than the value of 1.9 ± 0.8 s observed in patients who received midazolam with propofol. In the latter group the latency time of the swallowing reflex was significantly reduced following the administration of flumazenil but not placebo. In patients who received propofol without midazolam, the administration of flumazenil or placebo was not associated with significant changes in the latency times. There were also no significant differences in the latency times in the subgroup that received midazolam followed by flumazenil and the propofol alone groups that did or did not receive flumazenil. These results suggest that midazolam still exerts a depressive effect on the swallowing reflex 2 h after its administration despite the recovery of normal consciousness.
The severity of postischemic hypoperfusion increases with duration of cerebral ischemia in rats
Authors: KARLSSON B. R. , GRÖGAARD B. , GERDIN B. , STEEN P. A.
Published: January 2009

Regional cerebral blood flow was studied after a period of hypotensive bilateral carotid occlusion in rats. As other studies have found, we confirm that 15 min of ischemia caused an initial brief hyperemic episode followed by severe hypoperfusion in all areas. With varying duration of ischemia from 5 to 10, 15 and 20 min, the median cerebral blood flow 60 min postischemia was 79%, 46%, 48% and 34% of control, respectively. Thus the degree of postischemic hypoperfusion increased significantly with the duration of ischemia.
Redistribution of granulocytes during adrenaline infusion and following administration of Cortisol in healthy volunteers
Authors: TOFT P. , HELBO–HANSEN H. S. , TØNNESEN E. , LILLEVANG S. T. , RASMUSSEN J. W. , CHRISTENSEN N. J.
Published: January 2009

Major surgical procedures induce an endocrine metabolic stress response characterized by increased secretion of adrenaline and Cortisol. Furthermore, surgical stress is accompanied by granulocytosis in peripheral blood. The granulocytosis may be due to increased adrenaline and Cortisol secretion. The purpose of this study was to investigate the redistribution of granulocytes during adrenaline infusion and following administration of Cortisol. Granulocytes were isolated from peripheral blood from eight healthy volunteers, labelled with indium–111–tropolene and reinjected. The distribution of granulocytes was imaged by using a gamma camera and calculated with an interfaced computer three times during a control period and three times during a corresponding hour af adrenaline infusion 0.05 μg kg b.w.‐1 min‐1. The distribution was then measured every second h for another 6–h control period and then for 6 h following administration of Cortisol 3.6 mg kg b.w.‐1 Infusion of adrenaline resulted in granulocytosis in peripheral blood and a reduction of radioactivity of the spleen to 83.0% of the initial value. The effect of adrenaline on the bone marrow was negligible. Cortisol administration was followed by granulocytosis and decreased radioactivity of both the spleen (81.5%) and the bone marrow (79.8%). It is concluded that the spleen is an active immunological organ as both adrenaline and Cortisol induces efflux of granulocytes from the spleen. The Cortisol induced efflux of granulocytes from the bone marrow explains that granulocytosis also occurs in splenectomized patients after major surgery.
Partial attenuation of the cardiovascular responses to tracheal intubation with oral manidipine
Authors: MIKAWA K. , MAEKAWA N. , NISHINA K. , HASEGAWA M. , KAETSU H. , GOTO R. , YAKU H. , TAKAO Y. , OBARA H.
Published: January 2009

We conducted a placebo–controlled, randomized, and double–blinded study to evaluate the efficacy of manidipine given orally in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation. Thirty normotensive patients (ASA physical status 1) undergoing elective surgery were allocated to one of three groups (n= 10 for each); placebo, 5 mg manidipine, and 10 mg manidipine groups. These tablets were orally administered 3 h before induction of anaesthesia. Anaesthesia was induced with thiopentone 5 mg kg‐1 iv, and tracheal intubation was facilitated with vecuronium 0.2 mg–kg‐1. Laryngoscopy lasting 30 sec was attempted 2 min after induction of anaesthesia. Patients receiving placebo showed a significant increase in systolic and diastolic blood pressure associated with tracheal intubation. These increases following tracheal intubation were significantly reduced in patients receiving manidipine 10 mg compared with patients receiving placebo or manidipine 5 mg (P < 0.05). Oral administration of manidipine 10 mg before induction of anaesthesia is a simple and effective method for attenuating pressor response to laryngoscopy and tracheal intubation. We stressed that the potential beneficial effect of a reduced haemodynamic reaction to intubation might be obtained at the expense of hypotension later on.
The effect of metoprolol upon blood pressure, cerebral blood flow and oxygen consumption in patients subjected to craniotomy for cerebral tumours
Authors: FELDING M. , JAKOBSEN C.–J. , GOLD G. E. , DAVIDSEN B. , JENSEN K.
Published: January 2009

Hypertension and cerebral hyperperfusion are often seen in the immediate postoperative period after craniotomy for supratentorial tumours. Metoprolol is known to attenuate the postoperative hypertensive response after hypotensive anaesthesia and this study was carried out to evaluate the effect of metoprolol on cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRo2) before extubation and cerebral arteriovenous oxygen content difference (AVDo2), mean arterial blood pressure (MABP), Pao2 and Paco2 in a 180–min period after extubation. Twenty patients anaesthetized with thiopentone, fentanyl, nitrous oxide 67%, and halothane 0.5% were randomized to receive intravenous metoprolol or placebo at the end of the peroperative period. There were no significant differences in CBF– and CMRo2 values between the two groups. In the period between closure of the dura and 5 min after extubation, an increase in MABP was observed in the control group (P < 0.05), but not in the metoprolol group. During the same period a decrease in AVDo2 was observed in both groups (P < 0.05); during the next 10 min an increase was observed, but with no difference in AVDo2 values between the groups. A higher level of Pao2 in the metoprolol group was observed in the postoperative period. These findings suggest that peroperative treatment with metoprolol reduces postoperative MABP but does not influence the cerebral blood flow and metabolism.
Haemodynamic effects of pneumoperitoneum and the influence of posture during anaesthesia for laparoscopic surgery
Authors: ODEBERG S. , LJUNGQVIST O. , SVENBERG T. , GANNEDAHL P. , BÄCKDAHL M. , ROSEN A. VON , SOLLEVI A.
Published: January 2009

The laparoscopic operating technique is being applied increasingly to a variety of intra‐abdominal operations. Intra–abdominal gas insufflation, i.e. pneumoperitoneum (PP), is then used to allow surgical access. The haemodynamic effects of PP in combination with different body positions have not been fully examined. Eleven patients without signs of cardiopulmonary disease were studied before and during laparoscopic cholecystectomy under propofol–fentanyl anaesthesia with controlled ventilation. Swan‐Ganz and radial arterial catheterization were used to determine haemodynamic data in the horizontal position, with a 15–20° head–down tilt and a 15–20° head–up tilt. The measurements were repeated after insufflation of carbon dioxide to an intraabdominal pressure of 11–13 mmHg, as well as during surgery. The ventricular filling pressures of the heart were strictly dependent on body position. PP in the horizontal position increased pulmonary capillary wedge pressure by 32% (P < 0.01), central venous pressure by 58% (P < 0.01), and mean arterial pressure by 39% (P < 0.01). When PP was combined with a head–down tilt, there was a further increase in filling pressures by approximately 40% (P < 0.01), while the reduction in filling pressures during the head–up tilt was counteracted by PP. During PP with a head–up tilt, the filling pressures did not differ from those in the horizontal position without PP. CI showed a certain dependency on filling pressures. It is concluded that PP causes signs of elevated preload and afterload. The combination of PP and a head–up tilt is associated only with signs of an elevated afterload. It is suggested that the haemodynamic response to PP, especially in combination with a head–down tilt, may be hazardous to patients with compromised heart function.
The effects of wound infiltration with bupivacaine versus saline on postoperative pain and opioid requirements after herniorrhaphy
Authors: DlERKING G. W. , ØSTERGAARD E. , ØSTERGÅRD H. T. , DAHL J. B.
Published: January 2009

In a prospective, double‐blind, placebo‐controlled study, twenty‐eight healthy, male patients, aged 20–69 years, scheduled for unilateral elective inguinal herniorrhaphy ad modum Bassini were randomized to receive postoperative infiltration of the surgical wound with either bupivacaine 0.25%, or isotonic saline. General anaesthesia was induced with thiopentone 3–5 mg·kg‐1 and alfentanyl 10 μg·kg‐1, and maintained with alfentanyl 5 μg·kg‐1 15 min and N2O/O2. After herniorrhaphy, the internal fascia was infiltrated with bupivacaine 0.25% or saline, 10 ml. After closure of the external fascia, the subcutaneous tissue was infiltrated with bupivacaine 0.25% or saline, 15 ml on both sides of the surgical wound. Pain at rest, during mobilisation and during cough was significantly decreased in patients receiving bupivacaine compared to placebo. Median time to first request for morphine was increased from 25 min to 135 min, and the consumption of supplementary morphine during the 24 h study period reduced from four to two doses of 0.1 mg·kg‐1 iv or 0.125 mg·kg‐1 im, in patients who received bupivacaine compared to placebo.
Effects of hypothermia with and without buffering in hypercapnia and hypercapnic hypoxemia
Authors: WETTERBERG T. , SJÖBERG T. , STEEN S.
Published: January 2009

Anesthetized, paralyzed and mechanically ventilated pigs were hypoventilated to extreme hypercapnia (Paco2=20 kPa) at Fio2 0.5, and allotted to receive hypothermia (=31.5˚C) and buffer infusion, (HB–group, n = 6) or to a hypothermic control group (H–group, n = 6). The HB–group had higher arterial pH (7.34 vs 7.09, P < 0.01) and plasma bicarbonate (58.8 vs 35.4 mmol–l‐1, P < 0.01) than the controls, but lower mean pulmonary arterial pressure (MPAP), (16 vs 23 mmHg (2.1 vs 3.1 kPa), P < 0.01) and pulmonary vascular resistance (PVR), (512 vs 699 dyn–s–cm‐5 (5120 vs 6990 μN–s–cm‐5), P < 0.05). Mixed venous Po2 (Pvo2) was lower in the HB–group (5.1 vs 6.8 kPa, P < 0.01), as well as serum potassium (2.8 vs 3.7 mmol l‐1, P <0.01) and ionized calcium (1.01 vs 1.29 mmol l‐1, P <0.01). Subsequently, the inspired oxygen fraction (Fio2) was decreased stepwise (0.3, 0.25, 0.21, 0.15, 0.10) at 30 min intervals. At Fio2 0.3, the HB–group had lower Pvo2 (6.6 vs 7.8 kPa, P <0.01), O2 half saturation tension (3.6 vs 4.2 kPa, P <0.01), MPAP (17 vs 25 mmHg (2.3 vs 3.3 kPa, P <0.01) and PVR (598 vs 793 dyn–s–cm‐5 (5980 vs 7930 μN–S'cm‐5, P <0.05) compared with the controls, but higher arterial O2 saturation (95.3 vs. 88.6%, P < 0.01) and O2 content (17.7 vs 15.7 ml– 100 ml‐1, P <0.05). The groups did not differ in O2 delivery, in spite of their difference in arterial O2 content, because of a lower cardiac output in the HB–group (1.6 vs 2.2 l–min‐1, P <0.05). Mixed venous O2 content, O2 consumption and O2 extraction did not differ between groups. Combined use of hypothermia and buffering did not improve survival in hypercapnic hypoxemia as compared to a hypothermic regimen without buffer.