bluuebunny/crossref_metadata_2025 huggingface dataset:
Individual predictability of repeated spinal anaesthesia with isobaric bupivacaine
Authors: TUOMINEN M. , KUULASMAA K. , TAIVAINEN T. , ROSENBERG P. H.
Published: January 2009

To evaluate the individual predictability of the spread of spinal anaesthesia, an analysis of 38 patients who had had at least two spinal blocks within 4 years was performed. All spinal blocks were done with the patients in the lateral position at the midline in the interspace LIII–IV, injecting 3 ml of isobaric 0.5% bupivacaine. Regression analysis showed that the predictability of the maximal analgesic spread of the second anaesthesia from the first anaesthesia was highly significant (P < 0.0001). Therefore, if a higher or lower level of the block is required, another method for the forthcoming anaesthesia may be needed. The reasons for this phenomenon could not be clarified in this retrospective study.
Duration of action of vecuronium in infants and children anaesthetized without potent inhalation agents
Authors: KALU I. , MERETOJA O. A.
Published: January 2009

The duration of effect of vecuronium has previously been studied in paediatric patients only during inhalation anaesthesia. We therefore studied the age–related differences in duration of action after administration of 0.1 mg kg‐1 of vecuronium in 66% N2O in O2, fentanyl anaesthesia without inhalation agents. Forty–nine children (2 wk–14 yr, ASA 1–2) were selected for study and divided into four groups according to age. Evoked EMG monitor (Relaxograph, Datex, Finland) was calibrated with hypothenar muscle recording. The completely restored first twitch (T1) level was used as reference for recovery calculations. In infants (age < 1 yr) the onset time (68 s) was only 0.6–0.8 times that of older patients (P < 0.01). In infants the duration of surgical relaxation to Tl 10% (42 min) and the recovery index (21 min) were 1.7–2.9 times longer than in older patients (P < 0.01). It took 55 min from the beginning of recovery to full restoration of Tl in infants, compared with 20–24 min in 3–15–year–old children. Interestingly, the younger the child, the more rapidly train–of–four ratio recovered compared with T1 (P < 0.01). Because of the age–dependent prolongation of vecuronium relaxation and spontaneous recovery in small children, the level of relaxation should be monitored also in clinical practice.
Interactions between noradrenergic and cholinergic mechanisms involved in spinal nociceptive processing
Authors: GORDH T. , JANSSON I. , HARTVIG P. , GILLBERG P. G. , POST C.
Published: January 2009

Antinociceptive effects have been demonstrated after systemic and spinal administration of the adrenoceptor agonist clonidine and cholinomimetic drugs in animals and human. The present investigation was undertaken in rats to study the possible interactions between spinal noradrenergic and cholinergic mechanisms in modulating the reaction to nociceptive stimuli. Using the tail immersion test, an additive antinociceptive effect was found between intrathecal (IT) clonidine (10 ug) and physostigmine (15 Ig, IT). The effect of clonidine was attenuated by atropine (15 μg, IT). Physostigmine (15 μg, IT) antinociception, which was of short duration was abolished by atropine (15 ug, IT) and attenuated by phentolamine (20 μg, IT). Neostigmine (5 μg, IT) produced a prolonged antinociceptive response. In animals pretreated with 6–hydroxydopamine IT, leading to a selective depletion of spinal cord noradrenaline, physostigmine (15 ug, IT) was ineffective in altering the nociceptive test response. Neither clonidine, nor physostigmine produced changes in latency times in the hot plate test (58C) in the doses employed. In conclusion, a clear–cut interaction exists between spinal noradrenergic and cholinergic systems for antinociception. To explain the interactions, several possible mechanisms may be considered, including cholinomimetic effects produced by clonidine, and the presence of muscarinic receptors in the dorsal horn of the spinal cord.
Bell–shaped concentration–response curve for myocardial stimulation by glucocorticoids
Authors: SELLEVOLD O. F. M. , JYNGE P.
Published: January 2009

The isolated perfused rat heart was used to study the myocardial effects of glucocorticoid methylprednisolone sodium succinate (MPSS 0, 100, 500 and 1000 mg/1) in normoxic conditions. Various physiological variables including coronary flow rate (CFR), left ventricular developed pressure (LVDP), dP/dTmax, dP/dTmix, and heart rate (HR) were assessed. At the end of the perfusion period the hearts were freeze clamped and analyzed for tissue content of calcium and various metabolites. MPSS (500 mg/1) resulted in vasodilatation and inotropic stimulation. An increase was found in CFR (+17% 4), LVDP (+ 6% 1), dP/dTmax, (+13% 2), dP/dTmix, (+ 9% 3); (P< 0.05). Heart rate was depressed (– 14% 2,P< 0.05). MPSS (100 mg/1) had no effect on CFR or contractility. MPSS (1000 mg/1) resulted in a transient vasodilatation and a progressive myocardial depression. MPSS perfusion (100 and 500 mg/1) increased the adenine nucleotide pool and at all concentrations MPSS elevated the myocardial content of lactate. We conclude that in normoxic conditions there is a bell–shaped curve of myocardial inotropic stimulation by the glucocorticoid hormone, and also a stimulation of metabolism possibly by increased cellular supply of substrates.
Rebreathing, resistance and external work of breathing in three different coaxial Mapleson D systems
Authors: JONSSON L. O. , ZETTERSTROM H.
Published: January 2009

Using a lung model, rebreathing characteristics, resistance against gas flow and the external work of breathing were tested in three different coaxial Mapleson D systems: the Medicvent D system, the Bain original system and the Coax–II system. The rebreathing characteristics were found to be similar in all systems in both spontaneous and controlled ventilation. The Bain system was found to have the lowest resistance and work of breathing and the Coax–II system the highest. The differences were small and clinically insignificant. Both the resistance and the work of breathing increased with fresh gas flow. The resistance against expiration was found to be in the range 135–160 Pa at a total gas flow of 31 1– min‐1, which is well within the acceptable level. The resulting end–expiratory pressure was never above 100 Pa (1 cmH2O) in any system. We concluded that there was no clinically significant difference among the three systems despite differences in design. The coaxial Mapleson D systems can also be used safely with high fresh gas flows with regard to resistance and end–expiratory pressures.
The influence of thoracic epidural analgesia on transcapillary fluid balance in subcutaneous tissue
Authors: REIN K.–A. , STENSETH R. , MYHRE H. O. , LEVANG O. W. , KROGSTAD A.
Published: January 2009

Clinical observation and calculation of fluid balance have shown that patients undergoing aortocoronary bypass surgery with thoracic epidural analgesia (TEA) in addition to general anesthesia retain less fluid than patients having general anesthesia only. The present study was designed to investigate whether this effect could be explained by thoracic epidural analgesia influencing the transcapillary fluid balance, i.e. the transcapillary forces (COPpl, COPif, Pif). Interstitial fluid colloid osmotic pressure (COPif) and interstitial fluid pressure (Pif) were measured subcutaneously at heart level by the blister suction technique and the wick–in–needle technique, respectively. Simultaneously plasma colloid osmotic pressure (COPpl) was recorded. Sixteen male patients were allocated to two groups, one having general anesthesia only (controls, n = 8). The other group (TEA, n = 8) received, at the induction of anesthesia, bupivacaine 50 mg via an epidural catheter as an adjunct to general anesthesia. TEA was maintained by continuous infusion for 24 h postoperatively. Preoperatively no intergroup differences were observed in “the Starling forces” (COPpl, COPif, Paif). At the start of extracorporeal circulation COPpl was significantly lower in the TEA–group than in controls. During extracorporeal circulation the transcapillary COP–gradient (COPpl–COPif) was reversed in both groups. At the end of extracorporeal circulation Pif increased to a minor degree in the TEA–group and remained significantly lower than in controls from 3 to 24 h postoperatively. The subcutaneous interstitial tissue could be less expanded postoperatively in the TEA–group, also reflected by a lower increase in Pif.
Distribution of11 C–labelled morphine and pethidine after spinal administration to Rhesus monkey
Authors: GUSTAFSSON L. L. , HARTVIG P. , BERGSTRÖM K. , LUNDQVIST H. , LINDBERG B. S. , LÅNGSTRÖM B. , SVÄRD H. , RANE H. , TAMSEN A.
Published: January 2009

The kinetics of “C–labelled morphine and pethidine were studied by positron emission tomography (PET) at different levels of the spinal canal (C4, T4, T5, T6, LI and L6). Studies were performed in the Rhesus monkey after intrathecal and extradural administration of the drugs at the lumbar level (L3–L4 or L4–L5, seven experiments). Radioactivity 100–300 times higher than with even distribution in the body was measured initially near the site of injection for both morphine and pethidine, irrespective of the route of administration. After injection of pethidine, high activity was observed at the L6 and LI levels, whilst the radioactive uptake was lower at T6 (10–20% of those at lumbar level). Morphine–derived 11–radioactivity showed more constant levels along the spinal canal, except at C4 where radioactivity was low. In CSF taken from the cervical level the peaks of radioactivity of the two drugs appeared 80–170 min after injection. The importance of different distribution routes was quantified in a pharmacokinetic compartment model, using the above results. The systemic distribution was extensive, irrespective of drug or route of administration. From the site of injection the systemic distribution was at least 60 times larger than the rostral distribution within the spinal canal.
Early detection of inadvertent oesophageal intubation: pulse oximetry vs. capnography
Authors: GUGGENBERGER H. , LENZ G. , FEDERLE R.
Published: January 2009

The aim of our retrospective study was to evaluate the efficacy of routine pulse oximetry and capnometry for detection of oesophageal tube misplacement. Patients undergoing ENT interventions at our hospital arc routinely monitored by ECG, arterial blood pressure by cuff, capnography, and pulse oximetry. Beat–to–beat values of Sao2 and CO2. waveform were recorded by a graphic printer connected to a microcomputer, ASA I patients were routinely preventilated with Fio2 = 0.3, and ASA II–III patients with Fio2=1.0. Anaesthesia was performed by junior anaesthesiologists under the close supervision of a resident. During a 16–month period, 1372 patients were anaesthetized. The records of 21 patients with accidental oesophageal tube misplacement were available for retrospective evaluation. Nine patients were preventilated with FiO2 = 0.3 (ASA 1), 12 patients with Fio2 = 1.0 (ASA II–III). Rapid detection of oesophageal tube position as early as the first ventilation is possible by capnometry, because of the highly significant difference in end–tidal CO2. (0.2 + 0.2 vol%; tracheal intubation: 3.7 0.9 vol.%; P < 0.0001). The present advanced pulse oximetry method does not permit differentiation between oesophageal and tracheal tube position within 30 s in patients preventilated with Fio2 = 1.0. Oesophageal misplacement was detectable within 7.5 0.9 s in patients preventilated with Fio2 = 0.3 due to a 2.1 0.8% decrease in Sao2 (P < 0.001). Our results underscore the significance of capnometry for rapid detection of inadvertent oesophageal intubation. High–resolution pulse oximetry is a valuable supplement but not a substitute for capnometry.
Effects of oral clonidine premedication on concentrations of Cortisol and monoamine neurotransmitters and their metabolites in cerebrospinal fluid and plasma
Authors: POUTTU J. , TUOMINEN M. , SCHEININ M. , ROSENBERG P. H.
Published: January 2009

Forty–two healthy male patients (aged 19–40 years), undergoing orthopaedic surgery under spinal anaesthesia (3 ml isobaric 0.5% bupivacaine), were given clonidine 4.5 μg kg–1 orally either 2 (Group I, n= 10) or 4 (Group II, n=10) hours before the operation, diazepam 0.15 mg kg–1 orally (Group III, n=10) or a placebo tablet (Group IV, n= 12) 2 h before the operation. Plasma concentrations of Cortisol, noradrenaline (NA), adrenaline (A), 3,4–dihydroxyphenylglycol (DHPG) and dihydroxyphenylacetic acid (DOPAC) were assayed from venous blood samples just before premedication and just before the spinal block. Cerebrospinal fluid (CSF) concentrations of Cortisol, tryptophan, 5–hydroxyindoleacetic acid and catecholamine metabolites were assayed from a sample taken before the spinal block. The plasma NA concentrations of the patients in the groups receiving clonidine decreased clearly compared with the other groups (P < 0.05). The NA metabolite DHPG was also lower in Groups I and II than in Group III (P < 0.05) after premedication. Plasma A concentrations were lower in Groups I and III than in Group IV (P < 0.05). The CSF concentrations of the different substances were similar in all groups. In Group I the sensory blockade lasted significantly longer than in Group III (P<0.05) and the mean duration of motor blockade was longer in Group I than in Groups III and IV (P < 0.05). Two patients in both clonidine groups developed bradycardia (heart rate <45 min–1) requiring atropine treatment. The mean lowest heart rate was lower in Group I than in Groups III and IV (P < 0.05). The patients in Group II were more sedated than those in Group IV (P < 0.05), but the degree of fear was similar in all groups. No correlations were found between sedation or fear and the level of any of the hormones or metabolites.
Early detection of the TUR syndrome by marking the irrigating fluid with 1 % ethanol
Authors: HAHN R. G.
Published: January 2009

The ethanol concentration in the expired breath (EB–ethanol), the volumetric fluid balance and the serum sodium concentration were measured in the course of 60 transurethral resections of the prostate in which the irrigating fluid was 1.5% glycine + 1% ethanol. Measurement of EB–ethanol indicated absorption of irrigant at a rate of more than 150 ml in 10 min, as measured volumetrically. There was a significant direct linear relationship between EB–ethanol and the cumulative volume of irrigant absorbed (R2 = 0.83); this correlation was stronger when the duration of absorption was taken into account (R2 = 0.90). EB–ethanol was inversely related to the overall change in the serum sodium concentration during the operation (R2 = 0.88). Symptoms that are recognized components of the TUR syndrome developed in 8 of the 13 patients absorbing more than 1 1 of irrigant, while the ethanol exerted no adverse effects. The results of the study indicate that 1% ethanol is a suitable marker for monitoring irrigant absorption by means of the expired breath test in routine transurethral surgery. At this concentration the sensitivity of the test is adequate for detecting absorption, while the ethanol is less toxic than the irrigant fluid itself.
Propofol as an induction agent in children: pain on injection and pharmacokinetics
Authors: VALTONEN M. , IISALO E. , KANTO J. , ROSENBERG P.
Published: January 2009

The efficacy of lignocaine (1%) mixed with propofol in reducing pain on injection with propofol was studied in 40 children undergoing elective surgery in a double–blind, randomized comparison with glucose (5%). The pharmacokinetics of propofol in a single dose of 2.5 mg/kg was also studied in eight children participating in the same sfudy. Lignocaine (1 mg) significantly reduced pain on injection compared to the control group (P < 0.001). The induction characteristics of propofol were not affected by the lignocaine, and no undesirable interaction was found between the two drugs. The first–stage elimination half–life (tl/2|3) of propofol in children was shorter (mean 9.3 3.8 (s.d.) min) than the values found in adults. This pharmacokinetic alteration may have clinical significance following repeated administration or continuous infusion of propofol.
Recovery from fixed–dose midazolam–induced anaesthesia and antagonism with flumazenil for outpatient arthroscopy
Authors: ZUURMOND W. W. A. , VAN LEEUWEN L. , HELMERS J. H. J. H.
Published: January 2009

This study evaluated recovery after a fixed dose of midazolam as induction agent and the influence of flumazenil on recovery parameters in patients undergoing day–case surgery (arthroscopy of the knee). In 40 unpremedicated patients, anaesthesia was induced with midazolam 0.2 mg/kg, vecuronium bromide 0.1 mg/ kg intravenously and 3 vol.% isoflurane in oxygen prior to intubation. Anaesthesia was maintained with nitrous oxide 66% in oxygen and 0.9 vol.% isoflurane. Ten minutes after the end of anaesthesia 20 patients received 0.2 mg flumazenil intravenously, followed by increments of 0.1 mg at 60 s intervals until eye opening. Recovery was assessed by the time to eye–opening, to answering five set questions correctly, and to recovering ocular balance (Maddox Wing test), and by comparing pre– and postoperative performance in a pencil and paper test (the p–deletion test). With the exception of ocular balance, all parameters showed a quicker improvement without side–effects in the flumazenil group. After 4 h all patients were fit for discharge. One month after the procedure, all patients were satisfied with the anaesthesia. Full recovery took on average 1.5 days (range between 0 h–10 days). Whilst the technique employing a fixed dose of midazolam as induction agent gives satisfactory intraoperative anaesthesia for day–case arthroscopy, further improvement can be made with the use of flumazenil which hastens recovery.
Benzodiazepine antagonism by aminophylline
Authors: HØEGHOLM A. , STEPTOE P. , FOGH B. , CALDARA A. , PEDERSEN C.
Published: January 2009

A double–blind, randomised study was performed to investigate whether aminophylline could reverse the sedative effect of benzodiazepine and if it could shorten the observation time necessary after benzodiazepine sedation. Forty patients undergoing minor abdominal, urogenital or lower extremity surgery were given benzodiazepine to maintain a state of deep sedation after spinal or epidural analgesia was achieved. Postoperatively, the patients received either aminophylline, 110 mg, or physiological saline intravenously. The aminophylline–treated patients showed a significantly more rapid reversal of sedation, but after 30 min there was no difference between the two groups. It is concluded that aminophylline antagonizes the sedative effect of benzodiazepine, but in routine benzodiazepine sedation, aminophylline will not shorten the necessary observation period after sedation.
Residual curarization in the recovery room: atracurium versus gallamine
Authors: HOWARDY–HANSEN P. , RASMUSSEN J. A. , JENSEN B. N.
Published: January 2009

Residual curarization in the recovery room was evaluated in 19 patients randomly allocated to two groups with nine and ten patients in each group, respectively. In one group atracurium was used for relaxation, and gallamine was used in the other. Anaesthesia was achieved with thiopental, diazepam, fentanyl and nitrous oxide in oxygen. Mean train–of–four (TOF) ratio in the gallamine and atracurium group was 0.63 and 0.91, respectively. Fifty per cent of the patients in the gallamine group had TOF ratios below 0.70, and none of these patients were able to sustain a head lift for 5 s. All patients in the atracurium group had TOF ratios above 0.70, and all of them were able to lift their head for 5 s. All patients were fully awake when they were evaluated, and no patient had any sign of respiratory difficulty. We conclude that residual curarization in the recovery room remains a problem and that this problem seems to be reduced when muscle relaxants of intermediate duration of action are used for relaxation during operation.
Anaesthesia for computerised tomography of the brain in children: a comparison of propofol and thiopentone
Authors: VALTONEN M.
Published: January 2009

Propofol (2,6–di–isopropylphenol) 1.5–2.0 mg/kg i.v. was compared with thiopentone 3.0–4.0 mg/kg i.v. as an induction agent in anaesthesia for computerised tomography (CT) of the brain in children. Both induction agents were combined with diazepam 0.2 mg/kg i.v. Thirty children (ASA physical status I–II) aged 3 to 10 years and scheduled for elective examination were included in the randomized study. The haemodynamic response to propofol and thiopentone did not differ between the groups. Spontaneous respiration was retained in all patients and no ventilatory support was required during anaesthesia. The incidence of side–effects did not differ between the groups. Pain on injection with propofol was rare (n= 1) after mixing 1 ml lignocaine (1%) with propofol prior to induction. The recovery times were significantly shorter in the propofol than in the thiopentone group. Propofol appears to be a promising alternative for use in short day–case anaesthesia for CT scanning in children.
Epidural morphine delays gastric emptying and small intestinal transit in volunteers
Authors: THORÉN T. , TANGHÖJ H. , WATTWIL M. , JÄRNEROT G.
Published: January 2009

The influence of a painful stimulus and lumbar epidural morphine on gastric emptying, the orocecal transit time and small intestinal transit were studied in nine healthy volunteers. Acetaminophen absorption was used as a measure of the rate of gastric emptying. Orocecal transit time was determined by measuring the end–expiratory hydrogen concentration. Small intestinal transit was calculated from measurements of the orocecal transit time and gastric emptying. Cold pain stress with intermittent immersion of the feet in ice–cold water was used as a painful stimulus. Each volunteer was investigated on 3 different days: once after receiving 4 mg of epidural morphine and during cold pain; once during cold pain; and once under control conditions without pain and epidural morphine. Immersion of the feet in ice–cold water was always very painful, but was more tolerable during epidural morphine analgesia. The increase in blood pressure which accompanied the cold pain was the same whether this pain was induced without or during epidural morphine analgesia. Gastric emptying, orocecal transit time and small intestinal transit were delayed during epidural morphine analgesia compared with the findings under the control and plain cold pain conditions. Cold pain stress alone did not influence gastric emptying, orocecal transit time or intestinal transit. To conclude, epidural morphine in itself delayed gastric emptying, orocecal transit and transit through the small intestine in healthy volunteers.
Effects of droperidol, haloperidol and ketamine on halothane, succinylcholine and caffeine contractures: implications for malignant hyperthermia
Authors: FLETCHER J. E. , ROSENBERG H. , Lizzo F. H.
Published: January 2009

The effects of two structurally similar butyrophenones (droperidol and haloperidol) and ketamine were evaluated in an in vitro system to determine their potential for eliciting or exacerbating an episode of malignant hyperthermia. Muscle strips from patients referred for diagnostic testing for malignant hyperthermia and muscle strips from the rat diaphragm were exposed to droperidol, haloperidol, or ketamine prior to challenge with halothane, succinylcholine or caffeine. If any agent augmented the contracture response to the malignant hyperthermia triggering or diagnostic agents, then the agent was considered unsafe for use in malignant hyperthermia susceptible patients. Droperidol 10 μmol/1 and ketamine 100 μmol/l did not induce contractures in human or rat skeletal muscle when added alone, nor did they augment halothane, succinylcholine or caffeine contractures. These agents appear to be safe for use in patients susceptible to malignant hyperthermia. In contrast, haloperidol 10 μmol/1 augmented the response to succinylcholine about 1.5–fold and may be contraindicated in MH susceptibles.
Interaction of verapamil and halogenated inhalation anesthetics on hypoxic pulmonary vasoconstriction
Authors: KjÆ J. , BJERTNÆS L. J.
Published: January 2009

Calcium channel blockers and halogenated inhalation anesthetics reduce hypoxic pulmonary vasoconstriction (HPV) when administered separately to isolated rat lungs. This study was undertaken to investigate the effect of combining the calcium channel blocker verapamil with halothane or isoflurane. HPV was elicited in three groups of experiments. First, we studied the effect of halothane 1.3 MAC and varying concentrations of verapamil. Halothane reduced HPV as a mean by 34.7%, and a dose–dependent reduction was seen with verapamil. The depressant effect of the combination of halothane and verapamil was significantly greater than when the drugs were administered alone. We further investigated in separate groups the effects of varying concentrations of halothane and isoflurane, administered both separately and in combination with a constant dose of verapamil (1.02 nmol). Both anesthetics depressed HPV in a dose–dependent fashion. Verapamil reduced HPV as a mean by 34.2% and 39.3% in the halothane and isoflurane groups, respectively. The inhibition caused by combining verapamil with an anesthetic was significantly greater than when administered separately. We conclude that verapamil in combination with halothane or isoflurane has an additive dampening effect on HPV.
Effects of adenosine–induced hypotension on cerebral blood flow and metabolism in the pig
Authors: STÅNGE K. , LAGERKRANSER M. , RUDEHILL A. , SOLLEVI A.
Published: January 2009

The cerebral and systemic effects of hypotension induced by adenosine (0.61 0.07 mg–kg‐1 –min‐1) were studied in eight pigs anesthetized with droperidol, phenoperidine and nitrous oxide. Mean arterial blood pressure (MABP) was reduced by 58%, from 17.2 kPa (128 mmHg) to 6.9 kPa (53 mmHg) during a 30–min period. The hypotension was caused by a decrease in systemic vascular resistance (58%) while the cardiac output was unaffected. Cerebral blood flow (CBF), as determined by microsphere distribution, and the cerebral metabolic rate for oxygen (CMRo2) remained unchanged. Cerebral vascular resistance decreased by 61%. There were no signs of cerebral lactate release. After discontinuation of adenosine infusion, the MABP returned to control levels within 5 min. Thirty minutes later the CBF was increased by approximately 60%, in comparison to the control, while the CMRo2 was unchanged. It is concluded that adenosine–induced hypotension in pigs is associated with preserved CBF and CMRo2, whereas cerebral hyperperfusion is present in the early post–hypotensive period.
Train–of–four fade during onset of neuromuscular block with nondepolarising neuromuscular blocking agents
Authors: GIBSON F. M. , MIRAKHUR R. K.
Published: January 2009

Fade in the train–of–four (TOF) responses during onset of neuromuscular block was studied following administration of atracurium (225 or 450 μg/kg), vecuronium (40 or 80 μg/kg), pancuronium (60 or 120 μg/kg) and tubocurarine (450 μg/kg). TOF ratios were measured at approximate heights of T, (first response in the TOF) of 75, 50 and 25%. Fade in TOF increased as the height of T1decreased, with maximum fade being observed at T1of 25%. The greatest difference between relaxants was observed at T, of 25%, vecuronium showing the least fade and pancuronium, atracurium and tubocurarine showing increasing fade, in that order. The difference between atracurium and tubocurarine or between vecuronium and pancuronium was not significant, but the degree of TOF fade was significantly greater with atracurium and tubocurarine in comparison to vecuronium or pancuronium.
Acute hemodynamic effects of pericardial closure in man
Authors: DAMEN J. , BOLTON D. T.
Published: January 2009

The acute hemodynamic effects of pericardial closure were studied in 30 patients with normal left ventricular function, who were undergoing coronary artery bypass surgery. Closure of the pericardium resulted in decreases in arterial blood pressure (P < 0.01), cardiac index (P < 0.001), mean right atrial (P < 0.001), mean pulmonary artery (P < 0.001) and pulmonary capillary wedge pressure (P < 0.001). The observed hemodynamic changes are probably caused by a change in the ventricular pressure–volume relationships.
Intravenous administration of isosorbide dinitrate attenuates the pressor response to laryngoscopy and tracheal intubation
Authors: HATANO Y. , IMAI R. , KOMATSU K. , MORI K.
Published: January 2009

In order to evaluate the effect of isosorbide dinitrate (ISDN), administered as a bolus intravenous injection, on the circulatory response to tracheal intubation, mean arterial pressure (MAP), and heart rate (HR) in response to laryngoscopy for 30 s followed by tracheal intubation were compared in patients not receiving ISDN (control) and receiving 40 μg/kg or 80 μg/kg of ISDN 45 s before starting laryngoscopy. Each group consisted of 10 patients undergoing elective surgery. Forty–five seconds after starting laryngoscopy, MAP was significantly (P< 0.01) lower in patients receiving 80 μg/kg ISDN than in those receiving no or 40 μg/kg ISDN. HR increased to a similar extent in the three groups. These results indicate that a bolus injection of ISDN (80 μg/kg) is a simple, practical and highly effective means of attenuating the hypertensive response to direct laryngoscopy and tracheal intubation.
Systemic administration of N–acetylcysteine has no effect on postoperative lung function following elective upper laparotomy in lung healthy patients
Authors: JEPSEN S. , KLÆRKE A. , NIELSEN P. H. , NIELSEN S. T. , SIMONSEN O.
Published: January 2009

In a randomized, double–blind study, 131 consecutive patients, subjected to elective upper laparotomy, were prophylactically given the recommended dose of N–acetylcysteine (NAC) (Mucomyst, ASTRA) (200 mg × 3) or placebo against postoperative pulmonary complications. The effect was evaluated by lung function tests (VC and FEV1), arterial blood gas analyses and chest x–ray. No benefit could be demonstrated, either to postoperative pulmonary function or in the frequency of atelectasis in the recommended dose. However, no patients with preoperative bronchopulmonary disease demanding treatment with bronchodilatators were included in the study. A positive effect of NAC in this category of patients could not be excluded.
Attenuation of the pressor response to laryngoscopy and tracheal intubation with intravenous verapamil
Authors: NISHIKAWA T. , NAMIKI A.
Published: January 2009

This study was undertaken in surgical patients in order to evaluate the effects of intravenous verapamil on the circulatory responses to laryngoscopy and tracheal intubation. Laryngoscopy for tracheal intubation was initiated 1 min after thiamylal 5 mg·kg‐1 and succinylcholine 1.5 mg·kg‐1 in the control group (n = 21). The verapamil group (n = 23) received intravenous verapamil 0.1 mg·kg‐1 immediately after thiamylal–succinylcholine administration. The resulting changes in mean arterial pressure (MAP) and heart rate (HR) were continuously measured. Compared with the control group, MAP increased less in response to laryngoscopy and tracheal intubation (56 ± 13% versus 25 ± 15% above baselines, P < 0.01) and returned toward baseline sooner in patients receiving verapamil. For hypertensive patients, MAP increases from baseline after intubation were 18 ± 9% in the verapamil group, and 53 ± 14% in the control group, respectively (P < 0.001). Increases in HR response to laryngoscopy for intubation were comparable in both groups. We conclude that intravenous verapamil is effective in reducing pressor responses during endotracheal intubation, especially in hypertensive patients.
Spinal buprenorphine for postoperative analgesia after caesarean section
Authors: CELLENO D. , CAPOGNA G.
Published: January 2009

Two doses of intrathecal buprenorphine for postoperative analgesia have been compared. Forty–five women undergoing elective caesarean section under spinal anaesthesia were randomly divided into three groups. Group A (controls, n= 15) received hyperbaric bupivacaine; Groups B and C received the same but with the addition of 0.03 mg or 0.045 mg buprenorphine, respectively. Patients receiving buprenorphine had a longer pain–free interval than the controls (P < 0.01). Within the buprenorphine groups, patients receiving the higher dose had a longer effect (420 min s.d. 24) than those receiving the lower dose (173 min s.d. 31) (P < 0.01) without any increase in side–effects.
A slide–rule for assessment of venous admixture
Authors: ZETTERSTRÖM H.
Published: January 2009

Determination of venous admixture (physiological shunt, Qya/Qt) requires analysis of both arterial and mixed venous blood. When a pulmonary arterial catheter is not in use, the pulmonary oxygenating capacity may be assessed from arterial blood gas data, the fraction of inspired oxygen (Fio2) and an assumed value of the arterial–mixed venous oxygen content difference. To facilitate this process, a slide–rule based on the “virtual shunt” concept is presented. It permits rapid assessment of Qya/Qt from known values of arterial oxygen tension (Pao2) or saturation (Sao2) and Fio2 and may promote the choice of appropriate Fio2. The limitations of the slide–rule were studied theoretically and its validity was tested by comparing 100 determinations of virtual shunt with the corresponding Qya/Qt values. The slide–rule was found to estimate Qya/Qt more accurately than commonly used oxygenation indices such as the Pao2/Fio2 ratio.
Assessment of pain: a comparison between patients and doctors
Authors: FORREST M.
Published: January 2009

In a trial based on 52 patients admitted because of acute abdominal pain, we compared the assessment of pain intensity by doctors and patients according to a visual analogue scale. We found significant differences with regard to the median score of the doctors (3.4 cm) compared to the patients (6.1 cm). The correlation was 0.64 while the differences in dispersion were insignificant. Our findings indicate that it is far from unimportant who makes the pain assessment – the patient who experiences it or the doctor who evaluates it – but they also suggest that the differences could be a matter of scaling.
The presenting ECG pattern in survivors of cardiac arrest and its relation to the subsequent long‐term survival
Authors: Edgren E. , Kelsey S. , Sutton K. , Safar P. , Group The Brain Resuscitation Clinical Trial I Study
Published: January 2009

In a prospective multi‐center study, 262 patients were given general intensive care therapy following cardiopulmonary resuscitation if they were still comatose and unresponsive to pain 10 min after restored spontaneous circulation. Mortality (mainly cardiac) was 53.4% over the first 10 days, and 49% of the remaining survivors died between 10 days and 6 months. In the subsequent 6 months few patients died. Presenting electrocardiograms (ECG) showed ventricular fibrillation (VF) in 54.2%, asystole in 29.8% and electromechanical dissociation (EMD) in 9.2% of the patients. One‐year survival, 14.1% for asystole, 4.2% for EMD and 26.0% for VF and VT (ventricular tachycardia), differed significantly (P<0.01). VF/VT patients were older and had more cardiovascular disease. Adjustments of these and other covariates increased the significance of difference between ECG groups. Successful resuscitations from asystole or EMD appeared to be more common than has previously been reported, but this group of patients experienced an extremely high cardiac mortality over the first 6 months following resuscitation.
Decrease in plasma volume from intraabdominal trauma in rats
Authors: Akerström G. , Lundin S. , Lisander B.
Published: January 2009

Intraabdominal surgery tends to lower circulating blood volume by mechanisms unrelated to bleeding. This phenomenon was investigated in chloralose anesthetized rats. Plasma volume was determined with radiolabelled albumin. Animals were subjected to a standardized abdominal trauma, eliciting minimal bleeding and evaporation, and others served as controls. The trauma decreased plasma volume and increased hematocrit significantly, whereas the plasma concentration of labelled albumin followed a similar time course in traumatized animals and in controls. It is concluded that experimental abdominal trauma may decrease blood volume by a loss of fluid with virtually the same albumin concentration as that of plasma.
Local anesthesia prevents hypertension following application of the Mayfield skull‐pin head holder
Authors: Levin R. , Hesselvik J. F. , Kourtopoulos H. , Vavruch L.
Published: January 2009

A marked hypertensive response is often seen when the Mayfield skull‐pin device is applied to stabilize the head of the anesthetized patient for neurosurgery. In a prospective, blinded and randomized trial, 10 patients received an infiltration block of 0.5% mepivacaine with epinephrine 5 μg/ml (3 ml at each pin site) 1 min before the Mayfield holder was applied. Ten patients received normal saline and served as controls. All patients were under general anesthesia induced with sodium pentothal, fentanyl and pancuronium, and maintained with isoflurane in nitrous oxide/oxygen and increments of fentanyl. In the control group, there were significant increases in mean arterial pressure (mean increase 43%, P<0.001) and heart rate (15%, P< 0.01) at 0.5, 1 and 2 min after application. In the mepivacaine group, no significant changes occurred. Infiltration of local anesthetic with epinephrine can thus safely protect against potentially dangerous increases in arterial pressure when the Mayfield holder is used.
Deliberate hypotension induced by labetalol with halothane, enflurane or isoflurane for middle‐ear surgery
Authors: Toivonen J. , Virtanen H. , Kaukinen S.
Published: January 2009

The feasibility of using labetalol, an alpha‐ and beta‐adrenergic blocking agent, as a hypotensive agent in combination with inhalation anaesthetics (halothane, enflurane or isoflurane) was studied in 23 adult patients undergoing middle‐ear surgery. The mean arterial pressure was decreased from 86 ± 5 (s.e. mean) mmHg to 52 ± 1 mmHg (11.5 ± 0.7 to 6.9 ± 0.1 kPa) for 98 ± 10 min in the halothane (H) group, from 79 ± 5 to 53 ± 1 mmHg (10.5 ± 0.7 to 7.1 ± 0.1 kPa) for 129 ± 11 min in the enflurane (E) group, and from 80 ± 4 to 49 ± 11 mmHg (10.7 ± 0.5 to 6.5 ± 0.1 kPa) for 135 ± 15 min in the isoflurane (I) group. The mean H concentration during hypotension in the inspiratory gas was 0.7 ± 0.1 vol%, the mean E concentration 1.6 ± 0.2 vol%, and the mean I concentration 1.0 ± 0.1 vol%. In addition, the patients received fentanyl and d‐tubocurarine. The initial dose of labetalol for lowering blood pressure was similar, 0.52 – 0.59 mg/kg, in all the groups. During hypotension, the heart rate was stable without tachy‐ or bradycardia. The operating conditions regarding bleeding were estimated in a double‐blind manner, and did not differ significantly between the groups. During hypotension, the serum creatinine concentration rose significantly in all groups from the values before hypotension and returned postoperatively to the initial level in the other groups, except the isoflurane group. After hypotension there was no rebound phenomenon in either blood pressure or heart rate. These results indicate that labetalol induces easily adjustable hypotension without compensatory tachycardia and rebound hypertension.
Spontaneous recovery of residual neuromuscular blockade after atracurium or vecuronium during isoflurane anaesthesia
Authors: Erkola O. , Karhunen U. , Sandelin‐Hellqvist E.
Published: January 2009

With atracurium and vecuronium, spontaneous recovery of residual neuromuscular blockade monitored electromyographically during 0.5% isoflurane anaesthesia was studied in 60 patients undergoing plastic surgery. After thiopentone, in random order, either atracurium 0.5 mg kg‐1 or vecuronium 0.1 mg kg‐1 was administered and isoflurane added to N2O and O2 mixture. Following spontaneous recovery of both the single twitch amplitude (T1) to 75% of the control value and the train‐of‐four ratio (TOF ratio) to 75%, incremental doses of the relaxant were given to maintain the T1 at less than 10%. Before the end of surgery, the blockade was again permitted to recover spontaneously. During the initial spontaneous recovery, the mean recovery time of T1 from 25% to 75% (the recovery index) with atracurium was longer (P<0.001) than that with vecuronium (13.2 min and 10.1 min, respectively) but, during the second recovery, the mean recovery index was shorter (P<0.05) with atracurium than with vecuronium (16.1 min and 19.8 min, respectively). The recovery time from T1 75% to TOF ratio 75%, indicating the recovery rate of residual neuromuscular blockade, with atracurium was about 15 min after both the initial and the second recoveries. With vecuronium, the respective recovery times were significantly (P<0.001) longer (25.6 min and 38.5 min, respectively). It is concluded that with vecuronium there is slower spontaneous recovery of residual neuromuscular blockade than with atracurium.
EEG spectral power during halothane anaesthesia. A comparison of spectral bands in the monitoring of anaesthesia level
Authors: Yli‐Hankala A. , Eskola H. , Kaukinen S.
Published: January 2009

The EEG of ten elective abdominal surgery patients was studied during halothane anaesthesia. The EEG was analysed by compressed spectral array. The total power and various power bands were analysed. Anaesthesia was induced by mask with halothane in air. EEG analysis was performed from the data collected before induction and during anaesthesia at steady states of 1 MAC, 1.5 MAC, and 2 MAC. The correlation between deepening anaesthesia and power values was strongest in the 10–14 Hz band power and in the 18–32 Hz band power. This study confirms the usefulness of high frequency power in estimating the effect of halothane in patients.
The influence of 0.5 % isoflurane on a vecuronium‐induced neuromuscular blockade
Authors: Eriksson L. I. , Staun P. , Lennmarken C.
Published: January 2009

The influence of adding 0.5% isoflurane to a narcotic‐based anaesthesia on the duration of effect and recovery time after repetitive administration of vecuronium was studied in ten healthy patients. The twitch response in the adductor pollicis muscle was recorded after supramaximal train‐of‐four (TOF) stimulation of the ulnar nerve at the wrist. Prior to endotracheal intubation a bolus dose of vecuronium (0.08 mg/kg b.w.) was given. During surgery repeated injections of vecuronium (0.02 mg/kg b.w.) were administered at a TOF ratio of 0.25. Hand‐skin temperature, systolic blood pressure, end‐tidal CO2 and isoflurane concentrations were continuously monitored. Before and after 90 min administration of isoflurane, the duration of effect was 21 ± 4 and 24 ± 5 min (mean ± s.d., P<0.05) respectively. Corresponding recovery times were 270 ± 60 and 280 ± 70 s (n.s.). Skin temperature remained unchanged and systolic blood pressure showed only minor variations. The addition of 0.5% isoflurane to a narcotic‐based anaesthesia causes a moderate increase in duration of effect but no change in recovery time from a repetitive vecuronium‐induced neuromuscular blockade of 0.02 mg/kg.
The effect of lumbar epidural analgesia on the neurobehavioural responses of newborn infants
Authors: Kangas‐Saarela T. , Jouppila R. , Alahuhta S. , Jouppila P. , Hollmén A.
Published: January 2009

The effects of maternal lumbar epidural analgesia (ThlO‐L5) on the neonatal neurobehavioural response were studied at the ages of 3 h, 1 day, 2 days and 4–5 days. The subjects were healthy, full‐term neonates, born vaginally to 15 mothers with lumbar epidural block and 19 mothers without analgesia. Those delivered with epidural analgesia scored significantly better on alertness at the age of 3 h, 2 days and 4–5 days than the control group. No other statistically significant differences were found between the groups. The formation of the two groups according to the mothers' desire for epidural analgesia may have contributed to differences in the process of labour, but with this reservation it may be suggested that lumbar epidural analgesia may enhance the infant's recovery from the stress of labour and vaginal delivery.
Respiratory flow characteristics during isoflurane/nitrous oxide anaesthesia
Authors: Jonsson L. O. , Wahlgreen C.
Published: January 2009

Ventilatory characteristics during isoflurane anaesthesia and spontaneous breathing were studied in ten adults during surgery. After premedication with diazepam and induction with thiopental sodium and suxamethonium, 1.2% isoflurane in a 50% mixture of nitrous oxide in oxygen was introduced via a nonrebreathing circuit. Respiratory flow was measured by means of a pneumotachograph, arterial gases were sampled and carbon dioxide elimination and dead‐space to tidal volume ratios (Vd/Vt) calculated. The time axis of one respiratory cycle was divided into 20 equidistant sections and the flow at the end of each section was expressed as a percentage of the maximum flow rate during inspiration and expiration, respectively. In this manner, a relative respiratory flow pattern was constructed. The total ventilation was 5.8 ± 0.5 1. min‐1 (mean ± s.d.) with a tidal volume of 191 ± 45 ml and a respiratory rate of 31 ± 6 – min‐1. The Paco2 was 7.2 ± 0.6 kPa, the carbon dioxide elimination 151 ± 38 ml (STPD) and Vd/Vc>t 0.53 ± 0.12. The respiratory flow pattern showed early peak flows during both inspiration and expiration. The expiratory flow rate after 90% of the total respiratory cycle time was on average 43% of the maximum expiratory flow rate. The conclusion was that isoflurane seems to have a similar respiratory flow pattern to halothane. The significant hypercarbia that resulted is still acceptable but a lighter anaesthetic level is recommended for routine surgery.
Different activation patterns in the plasma kallikrein‐kinin and complement systems during coronary bypass surgery
Authors: Kongsgaard U. E. , Smith‐Erichsen N. , Geiran O. , Amundsen E. , Mollnes T. E. , Garred R
Published: January 2009

Components of the plasma kallikrein‐kinin and complement systems were determined in patients undergoing open heart surgery with cardiopulmonary bypass. Spontaneous kallikrein activity (KK), plasma prekallikrein (PKK), functional kallikrein inhibition capacity (KKI), C3 activation products (C3‐act), and the terminal complement complex (TCC) were measured. A marked, transitory increase in KK and a decrease in PKK were found prior to cardiopulmonary bypass just after heparin injection. An additional decline in PKK and KKI during bypass with a return to near control levels in the postoperative period was observed. C3‐act increased in all patients during bypass, reaching a peak value at wound closure. The TCC concentration also increased significantly during cardiopulmonary bypass, returned to control levels in the early postoperative period, and then increased again in the late postoperative period. It is concluded that activation of the kallikrein‐kinin system started after injection of heparin, prior to cardiopulmonary bypass. Activation of both the initial and the terminal complement cascade, however, started only after onset of cardiopulmonary bypass.
Mental function in elderly men after surgery during epidural analgesia
Authors: Asbjórn J. , Jakobsen B. W. , Pilegaard H. K. , Blom L. , ØStergaard A. , Brandt M. R.
Published: January 2009

To evaluate whether there is a difference in mental function after general anaesthesia and epidural analgesia, a homogeneous group of 40 elderly men (age between 60 and 80) undergoing transurethral prostatectomy was studied. The study was prospective, randomised and double blind. Patients with all types of complications believed to impair mental function were excluded. Long‐term, short‐term, verbal and visual memory were tested preoperatively, and 4 days, and 3 weeks postoperatively. In conclusion, we found a significant and equal decline in test performance on the fourth postoperative day. Three weeks postoperatively, however, both groups had returned to or exceeded preoperative levels of performance.