bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhaled nitric oxide lowers pulmonary capillary pressure and changes longitudinal distribution of pulmonary vascular resistance in patients with acute lung injury
Authors: BENZING A. , GEIGER K.
Published: January 2009

In acute lung injury (ALI), where pulmonary microvascular permeability is increased, transvascular fluid filtration depends mainly on the hydrostatic capillary pressure. In the presence of intrapulmonary vasoconstriction pulmonary capillary pressure (PCP) may increase thereby promoting transvascular fluid filtration and lung oedema formation. We studied the effect of 40 ppm inhaled nitric oxide (NO) on PCP and longitudinal distribution of pulmonary vascular resistance (PVR) in 18 patients with ALI.

PCP was estimated by visual analysis of the pressure decay profile following pulmonary artery balloon inflation. Contribution of venous pulmonary resistance to total PVR was calculated as the percentage of the pressure gradient in the pulmonary venous system to the total pressure gradient across the lung.

Inhalation of 40 ppm NO produced a prompt decrease in mean pulmonary artery pressure (PAP) from 34.1 6.8 to 29.65.7 (s.d.) mmHg; (P < 0.0001). PCP declined from 24.86.2 to 21.65.2 mmHg; (P < 0.0001) while pulmonary artery wedge pressure (PAWP) did not change. PVR decreased from 16673 to 12850 dyn sec cm‐5; (P < 0.0001). Pulmonary venous resistance (PVRven) decreased to a greater extent (from 7641 to 5028 dyn. sec. cm‐5; (P < 0.001) than pulmonary arterial resistance (PVRart) (from 9036 to 7929 dyn sec cm‐5; (P < 0.01). The contribution of PVRven to PVR feU from 44.310.8 to 37.811.9%; (P < 0.01). Cardiac output (CO) remained constant. The findings demonstrate that NO has a predominant vasodilating effect on pulmonary venous vasculature thereby lowering PCP in patients with ALI.
The potential of an anaesthesiologist–manned ambulance service in a rural/urban district
Authors: WlSBORG T. , GUTTORMSEN A. B. , SøRENSEN M. B. , FLAATTEN H. K.
Published: January 2009

The use of anaesthesiologists in prehospital emergency care is controversial. We wanted to assess the impact of an anaesthesiologist and a short time interval from acceptance of a mission to take–off at survival rates in a rural/urban emergency medical service. Prospectively registered data for 991 consecutive patients through a 12–month period were retrospectively evaluated by an independent foreign expert. Of all primary missions, 3.3% were considered probably lifesaving from site of injury to receiving hospital. Of these, the lifesaving result in 50% were dependent on both the qualifications of the anaesthesiologist and a short response time. Survival from hospital admission to discharge was 44%. All patients were discharged to their own homes, able to live a fully functional life. The consistent use of anaesthesiologists compared to less qualified personnel and the maintaining of response times below presently required minima doubles the potential for lives saved in services comparable to the one studied.
Comparison of propofol/alfentanil anaesthesia with isoflurane/N2O/fentanyl anaesthesia for renal transplantation
Authors: KIRVELA M. , YLI–HANKALA A. , LINDGREN L.
Published: January 2009

Total intavenous anaesthesia (TIVA) with propofol and alfentanil was compared with balanced anaesthesia (BA) in 30 uraemic patients undergoing renal transplantation. TIVA (n=15) was induced with propofol and alfentanil and maintained with propofol and alfentanil infusions, which were started immediately after induction. Thereafter the infusion rates were adjusted as needed. Ventilation was with oxygen in air. BA (n= 15) was induced with thiopentone and fentanyl and maintained with isoflurane/N20/fentanyl. Vecuronium was used for muscle relaxation in both groups. Mean infusion rates for propofol and alfentanil were 10 1.8 mg kg‐1 h‐1 and 70 9 μg kg‐1 h‐1, respectively. To control hypertension during TIVA, larger amounts of propofol and alfentanil were needed and slower recovery was observed than in previous studies in ASA 1–2 patients. Also, significantly more vecuronium was needed during TIVA than during BA (P < 0.05). The recovery parameters were similar in both groups, except for the occurrence of nausea, which was less after TIVA. In conclusion, TIVA had no clinical advantages over BA.
Renal effects of human atrial natriuretic peptide in patients after major vascular surgery
Authors: BERGMAN A. , ODAR–CEDERLOF I. , THEODORSSON E. , WESTMAN L.
Published: January 2009

The effects were studied postoperatively of an infusion of atrial natriuretic peptide (ANP) 7.5 pMol–kg‐1 –min‐1 on renal function and haemodynamics in seven patients who had been operated with insertion of an abdominal aortic graft. Urine flow, glomerular filtration rate (GFR), renal plasma flow (RPF) and excretion of electrolytes and osmoles were measured for three periods of 20 minutes during infusion of ANP, in the morning of the day after surgery. Haemodynamic studies were conducted, and serum levels of ANP, catecholamines and plasma renin activity were measured.

ANP levels increased from 52 to approximately 250 pMol–L‐1 during ANP infusion and decreased after infusion to a level equal to baseline. GFR increased from 92 mL–min“1 by 58, 20 and 21%, respectively. RPF was unchanged. Urine flow rate increased from 1.99 mL–min”‘ by 81, 151 and 173%, respectively. Fractional clearances of sodium, chloride and osmoles were increased during the second and third ANP periods whereas fractional potassium clearance did not change during the study. There were no changes in catecholamine levels or plasma renin activity during the study. Heart rate, mean arterial pressure and calculated systemic and pulmonary vascular resistance did not change whereas reductions occurred in cardiac index, mean pulmonary artery pressure, pulmonary artery wedge pressure and mean right atrial pressure. We conclude that infusion of ANP also in the postoperative situation increases GFR, diuresis and sodium excretion.
Simulation of inhalational anaesthetic uptake using a lung model with charcoal
Authors: JANOSA A. D. , ZBINDEN A. M. , FEIGENWINTER P.
Published: January 2009

A physical lung model for simulation of volatile anaesthetic uptake is described. Two communicating water–fined chambers simulate pulmonary mechanics allowing adjustment of functional residual capacity, resistance and compliance. The uptake of the volatile anaesthetics is reproduced by pumping gas from the lung chamber through a charcoal absorber at different rates; using a second pump for a bypass an arterial to end–tidal gradient can be generated. Changes of cardiac output are simulated by adjusting pump speed and of alveolar ventilation by adapting the ventilator setting. The results are reproducible and correspond with patient studies and computer stimulation, not necessitating empirical correction factors as in a previously described oil–based lung model. The model can serve as a teaching instrument, for the comparison and testing of anaesthetic equipment and the development of feedback systems.
Spinal anaesthesia with 29 gauge Quincke point needles and post dural puncture headache in 2,378 patients
Authors: DITTMANN M. , SCHAEFER H.–G. , RENKL F. , GREVE I.
Published: January 2009

Two thousand three hundred and seventy–eight spinal anaesthetics using a 29 G Quincke point needle were administered in a District Hospital between May 1983 and December 1991. The overall post dural puncture headache rate (PDPH) was 1.2% with a maximum of 2.5% in patients between age 30 and 39. PDPH was related to the experience of using 29 G needles (0.5% in consultants versus 2.0% in trainees, P<0.05).
Fentanyl and propofol uptake by the lung: effect of time between injections
Authors: MATOT I. , NEELY C. F. , KATZ R. Y. , MARSHALL B. E.
Published: January 2009

The effect of time between the administrations of fentanyl and propofol on the first pass uptake of propofol in the cat lung was studied using double indicator dilution technique. The pulmonary first pass uptake of propofol (mean s.e.mean) was 58 6% in six cats (control group) that had received no fentanyl prior to propofol (1 mg/kg) administration. The uptake was significantly reduced to 32 3% in animals pretreated with fentanyl (1 μg/kg) 30 seconds before propofol administration (n = 6). However, when fentanyl was administered 3 minutes (n = 6) or 10 minutes (n = 6) prior to propofol, the pulmonary uptake of propofol (45 5%, 507% respectively) was not significantly reduced. The results demonstrate that the ability of fentanyl to inhibit pulmonary removal of propofol depends on its time of administration prior to propofol. These data may have clinical implication with respect to timing of the preinduction opiate injection.
Decreased incidence of headache after accidental dural puncture in caesarean delivery patients receiving continuous postoperative intrathecal analgesia
Authors: COHEN S. , AMAR D. , PANTUCK E. J. , SINGER N. , DIVON M.
Published: January 2009

To examine the effects of prolonged (> 24 h) intrathecal catheterization with the use of postoperative analgesia on the incidence of post–dural puncture headache (PDPH), charts of 45 obstetric patients who had accidental dural puncture following attempts at epidural block were reviewed retrospectively. Three groups were identified: Group I (n = 15) patients had a dural puncture on the first attempt at epidural block, but successful epidural block on a repeated attempt; Group II (n=17) patients had a dural puncture with immediate conversion to continuous spinal anaesthesia with catheterization lasting only for the duration of caesarean delivery; Group III (n= 13) patients had an immediate conversion to spinal anaesthesia and received post–caesarean section continuous intrathecal patient–controlled analgesia consisting of fentanyl 5 (ig'ml‐1 with bupivacaine 0.25 mg·ml‐1 and epinephrine 2 μg·ml‐1 with catheterization lasting >24 h. No parturient in group III developed a PDPH. This was substantially lower (P < 0.009) than the 33% incidence for group I and the 47% incidence for group II. The incidence of a PDPH did not differ between group I and II. Similarly, there was no difference between group I and II with regard to requests for a blood patch. Patients receiving continuous intrathecal analgesia had excellent pain relief, could easily ambulate and none complained of pruritus, nausea, vomiting, sensory loss or weakness. In conclusion, indwelling spinal catheterization > 24 h with continuous intrathecal analgesia following accidental dural puncture in parturients may for some patients be a suitable method for providing PDPH prophylaxis and postoperative analgesia.
Changes in the EEG power spectrum after midazolam anaesthesia combined with racemic or S – (+) ketamine
Authors: HERING W. , GEISSLINGER G. , KAMP H. D. , DINKEL M. , TSCHAIKOWSKY K. , RUGHEIMER E. , BRUNE K.
Published: January 2009

Changes in the EEG power spectrum were studied in 50 patients (ASA status I or II), receiving either 2 mg·kg‐1of racemic ketamine or 1 mg kg‐1of S – (+) ketamine in a randomized and double‐blind manner after prior administration of 0.1 mg·kg‐1of midazolam. The patients receiving intramuscular premedication with midazolam about 45 minutes prior to induction of anaesthesia showed, in a deliberately quiet environment and mostly in the early morning, a delta dominated EEG (56% delta power) with a reduced alpha peak (17% alpha power) and an average median of 4 Hz as the baseline findings of the EEG power spectrum. The intravenous administration of midazolam led to activation of the lower beta range (13–18 Hz) and the subsequent injection of ketamine caused an increase in activity in the fast beta range (21–30 Hz), both being accompanied by a reduction of delta power from 56% to 40%. Correspondingly, an increase in the median frequency was noted. Causing nearly the same changes in EEG, S – (+) ketamine was confirmed to be twice as potent as racemic ketamine.
Effects of intrathecal clonidine on duration of bupivacaine spinal anaesthesia, haemodynamics, and postoperative analgesia in patients undergoing knee arthroscopy
Authors: NlEMI L.
Published: January 2009

Clonidine, an alpha–2–adrenergic agonist, may have a clinically relevant analgesic action but also a hypotensive action, when administered spinally. In this study, therefore, the analgesic and circulatory effects of intrathecal clonidine were studied in patients undergoing knee arthroscopy under spinal anaesthesia. Forty ASA I–II patients were randomly divided to two groups. One group received clonidine 3 μg–kg‐1mixed with 15 mg 0.5% bupivacaine and the other group an identical saline volume mixed with bupivacaine as above, in a double–blind fashion. Sensory analgesia, blood pressure, heart rate and sedation were followed during and after the operation. Oxycodone 0.14 mg– kg“‘ i.m. or ketoprofen 100 mg p.o. was administered when needed. The duration of sensory analgesia (until regression of the block to L2) was longer in the clonidine group (mean 217 min) than in the control group (mean 160 min) (P< 0.05). Duration of motor blockade was also longer in the clonidine group (mean 215 min) compared to the control group (161 min) (P< 0.05). Mean arterial pressure and heart rate were significantly lower in the clonidine group compared to the control group. The clonidine patients needed fewer supplemental doses of oxycodone (8 doses) than those in the control group (16 doses) (P< 0.05). More patients in the clonidine group were sedated 3–6 h after the injection (P< 0.05). Addition of clonidine prolonged the bupivacaine spinal block. However, marked haemodynamic changes and sedation may limit the usefulness of intrathecal clonidine.
Pharmacokinetics and pharmacodynamics of eltanolone (pregnanolone), a new steroid intravenous anaesthetic, in humans
Authors: CARL P. , HØGSKILDE S. , LANG–JENSEN T. , BACH V. , JAGOBSEN J. , SØRENSEN M. B. , GRÄLLS M. , WIDLUND L.
Published: January 2009

Eltanolone, a new intravenous steroid anaesthetic agent was administered intravenously in a dose of 0.6 mg kg‐1over 45 s to eight healthy male volunteers to evaluate some of its pharmacokinetic and pharmacodynamic effects. Drug concentration–time data were analysed by PCNONLIN, a non–linear regression programme, showing data consistent with a three–compartment model with initial distribution half–life tl/2Xi between 0.3 and 2 min, intermediate distribution half–life 11/22 between 12 and 29 min and terminal half–life tl/2.z between 72 and 212 min. The total body clearance of eltanolone was rapid and with individual values in the range 1.6–2.3 l'h‐1kg‐1. Eltanolone was initially distributed into a relatively large central compartment V| between 0.09 and 0.98 1·kg‐1and then extensively further distributed (Vss between 1.80 and 5.44 1 kg‐1and V between 4.87 and 11.87 1 kg‐1). The excretion of unchanged of eltanolone in urine was very small, the renal clearance was less than 0.5% of the total clearance. Induction of anaesthesia was trouble free with onset and duration of anaesthesia between 1 –2 min and 6–13 min, respectively. There was slight respiratory depression, a small transient increase in heart rate, and a maximum reduction in arterial blood pressure of 23%, as compared widi the resting level. Pain on injection and venous sequelae were not seen. Involuntary movements were seen in one subject. We conclude that eltanolone has a favourable pharmacokinetic profile with relatively rapid half–lives, large distribution volumes and rapid total body clearance. Moreover, eltanolone was found to produce smooth and reliable induction of anaesthesia with only minor cardiorespiratory changes and without pain on injection.
Neurologic symptoms after epidural anaesthesia. Report of three cases
Authors: GEMMA M. , BRICCHI M. , GRISOLI M. , VISINTINI S. , PAREYSON D. , SGHIRLANZONI A.
Published: January 2009

We describe 3 patients, who exhibited neurological symptoms after single dose epidural anaesthesia. In patient 1 an unrecognized spinal arteriovenous fistula (AVF) caused paraparesis following epidural block. The dilated veins draining an AVF are space–occupying structures and the injection of the anaesthetic solution may have precipitated latent ischaemic hypoxia of the spinal cord due to raised venous pressure. In patient 2, epidural block was followed by postoperative permanent saddle pain and hypoaesthesia. The injection of the anaesthetic in a narrow spinal canal with multiple discal protrusions and restriction of interlaminar foramina may have acutely produced mechanical compression of the spinal cord or roots. Patient 3 exhibited post–epidural block spinal arachnoiditis. Although the few reported cases of this syndrome exhibit severe neurological damage, our patient presented with scarse symptoms.

Our cases point out the importance of accurate neurological history and examination of candidates for epidural anaesthesia and of accurate anaesthetic history for neurological patients.
Anaesthesia for abdominal vascular surgery in patients with coronary artery disease (CAD), part I: isoflurane produces dose–dependent coronary vasodilation
Authors: HOHNER P. , NANCARROW C. , BACKMAN C. , HÄGGMARK S. , JOHANSSON G. , FRIDÉN H. , DIAMOND G. , FRIEDMAN A. , REIZ S.
Published: January 2009

The effects of anaesthesia for major abdominal vascular surgery on coronary flow regulation and mechanisms of myocardial ischaemia were studied in 56 patients with CAD, using a randomized, partly double–blinded protocol. After induction with fentanyl (3 μg–kg‐1) and thiopentone (2–4 mg kg‐1) and tracheal intubation, principal anaesthetics were nitrous oxide/oxygen (60/40) with isoflurane (n = 20), halothane (n = 19) or fentanyl (15–20 μg kg‐1) (n = 17). Conventional invasive techniques and coronary venous retrograde thermodilution were used to assess systemic and coronary haemodynamics. Coronary vascular resistance was estimated from myocardial oxygen extraction. Myocardial ischaemia was diagnosed by 12–lead ECG and/or anterior wall motion abnormalities by cardiokymography and/or myocardial lactate production. When adjustment of anaesthetic dose was insufficient for haemodynamic control, iv phenylephrine and nitroglycerine were adminstered to treat hypotension and hypertension or cardiac failure respectively. Measurements were performed at four specific intervals; awake, before surgery and 10 and 30 min after abdominal incision.

Comparable changes of systemic haemodynamics and myocardial oxygen consumption were observed in the three groups. Coronary vasodilation was evidenced in isoflurane patients only and was linearly dose–dependent (P< 0.001). Partial Least Squares Projections to Latent Structures modelling with cross validation confirmed this dose–dependency and ruled out a clinically measurable influence by intervention drugs or simultaneous systemic haemodynamic abnormalities.

The incidence of myocardial ischaemia during anaesthesia and surgery was comparable in the three groups (35, 37 and 24%, respectively) and there was an association with systemic haemodynamic aberrations in 19 of the 27 ischaemic episodes. In contrast to ischaemic halothane and fentanyl patients, isoflurane patients with ischaemia had significantly lower myocardial oxygen extraction (P= 0.008 andP= 0.001, respectively), indicating that the oxygen extraction reserve was not utilized in a normal way during ischaemia.
Anaesthesia for abdominal aortic surgery in patients with coronary artery disease, part II: effects of nitrous oxide on systemic and coronary haemodynamics, regional ventricular function and incidence of myocardial ischaemia
Authors: HOHNER PER , BACKMAN CHRISTER , DIAMOND GEORGE , FRIEDMAN ARNOLD , HÄGGMARK SÖREN , JOHANSSON GÖRAN , KARP KJELL , REIZ SEBASTIAN
Published: January 2009

This study examines the effects of nitrous oxide on haemodynamics, anterior left ventricular (LV) function and incidence of myocardial ischaemia in abdominal vascular surgical patients with coronary artery disease. Forty–seven patients were randomly assigned to isoflurane–fentanyl anaesthesia with nitrous oxide–oxygen vs airoxygen (control). Systemic and coronary haemodynamics, 12–lead ECG, LV anterior wall modon by cardiokymography (CKG) and myocardial lactate balance were recorded at four intervals: before and during anaesthesia and 10 and 30 minutes into surgery. Systemic haemodynamics were controlled by anaesthetic dose, and, when insufficient, by iv nitroglycerine (NG) in case of LV failure (PCWP > 18 mmHg) and by phenylephrine during hypotension.

We found that nitrous oxide was associated with greater need for iv nitroglycerin (patients:P= 0.031, episodesP= 0.005) and more myocardial ischaemia (patientsP= 0.012, episodesP= 0.00l) despite systemic and coronary haemodynamics comparable to the control group. We conclude that nitrous oxide, known to have both sympathomimetic and cardiodepressive actions, produced cardiodepression in the face of sympathetic stimulation. Our study design did not allow us to conclude if myocardial ischaemia was the consequence of increased wall stress or a reason for the observed LV dysfunction. The higher incidence of introperative myocardial ischaemia and need for NG did not cause increased cardiac morbidity.
Thoracic epidural analgesia compared with patient controlled intravenous morphine after upper abdominal surgery
Authors: GEORGE K. A. , WRIGHT P. M. C. , CHISAKUTA A. M. , RAO N. V. S.
Published: January 2009

Twenty–one ASA I or II patients undergoing upper abdominal surgery were studied for 24 hours after operation. They were entered into a prospective, randomised study of patient–controlled intravenous morphine compared with continuous thoracic epidural fentanyl combined with 0.2% bupivacaine. Pain relief was superior in the bupivacaine series (P < 0.05) throughout the 24 hour study period and this was associated with significantly greater pulmonary ventilation compared with the PCA series. Forced expiratory parameters were reduced in both series after the operation but significantly less so in the epidural group. There was a reduced incidence of emetic symptoms in the epidural group (P < 0.05) but the incidence of other minor side effects did not differ significantly. Thoracic epidural fentanyl/bupivacaine results in significantly better analgesia than patient–controlled intravenous morphine.
F. MAGORA1
Authors: GOZAL Y.
Published: January 2009

Control of postoperative pain is an important element in preventing the modification of the excitability of the dorsal horn neurons. We studied the efficacy of bupivacaine 0.5% wound infiltration for postoperative pain management following thyroid surgery. Forty consecutive ASA I–II patients, scheduled for thyroidectomy, were assigned randomly to two groups. Group I (n = 20) consisted of patients receiving bupivacaine 0.5% (10 ml) wound infiltration at the end of surgery and group II (n = 20) included patients without infiltration. The patients did not know whether the wound had been anaesthetized or not. All patients received balanced inhalational anaesthesia, including fentanyl (a total dose of up to 4 μg·kg‐1). Postoperative pain medication included morphine IV or IM, as needed. Twenty–four hours after surgery the worst pain was recorded using a visual analogue scoring system, from 0 to 10. Twenty–four hour postoperative morphine requirement was recorded. Groups did not differ in demographic data. Pain scores were significantly different in the two groups. In group I, the mean pain score was 3.7 × 1.6 compared with 6.9 × 1.7 in group II (P < 0.05). Only six patients (30%) in group I received opioids and only one of these (5%) had a pain score above 5. In comparison, 18 patients (90%) in group II received morphine during the first postoperative day. The local injection of bupivacaine corresponds to a block of the superficial branches of the cervical plexus. This study demonstrated a simple, efficient and safe way to reduce pain perception following a thyroidectomy.
Inhibitory effects of halo thane on high K+–induced canine tracheal smooth muscle contraction and intracellular Ca 2+ increment
Authors: YAMAKAGE M. , KAWAMATA T. , KOHRO S. , NAMIKI A.
Published: January 2009

Halothane is a potent bronchodilator. The effects of halothane on isolated canine tracheal smooth muscle contraction and intracellular Ca2+increment induced by a high concentration of K+were investigated to clarify how this anaesthetic decreases intracellular Ca2+concentration ([Ca2+]i), an important second messenger. The tension of the muscle strips was measured using an isometric transducer, and [Ca2+]i was measured using a surface fluorescence spectroscopy. Exposure to a 72.7 mM K+solution increased muscle tension and [Ca2+]i. Halothane (1,2,3 and 4% at the vaporiser) was introduced by bubbling in the presence of the 72.7 mM K+, and significantly decreased both this elevated muscle tension and the [Ca2+]i in a concentration–dependent manner. Similarly, slowly decreasing concentrations of K+(48.5, 36.4, 24.2 and 18.2 mM) significantly decreased both of these variables. There was no significant difference between the slopes of the two regression lines of changes in muscle tension and changes in [Ca2+]i. From the evidence that tonic increase in [Ca2+]i by high concentrations of K+is due to the influx of Ca2+via L–type voltage channels, halothane may modify the L–type channels to decrease Ca2+influx. In conclusion, halothane inhibits the high K+–induced canine airway smooth muscle contraction by decreasing [Ca2+]i. The decrease in [Ca2+]i by halothane might be due to inhibition of voltage–operated channels, especially the L–type channels.
Platelet activation in major surgical stress: influence of combined epidural and general anaesthesia
Authors: NAESH O. , HINDBERG I. , FRIIS J. , CHRISTIANSEN C. , PEDERSEN T. , TRAP–JENSEN J. , LUND J. O.
Published: January 2009

Platelets are activated in surgery releasing vasoactive substances such as serotonin and thromboxane. Platelets become temporarily hypoaggregable during surgery followed by a postoperative hyperaggregability. Local anaesthetics are known to inhibit platelet function but earlier reports are conflicting. In order to study the impact of the combined use of general and regional anaesthesia on platelet function during major surgery 16 otherwise healthy patients were randomised to either general anaesthesia (GA) (n = 8) or GA combined with epidural anaesthesia (GA + EPI) (n = 8) for elective upper abdominal surgery. Cyclic 3′5′adenosine monophosphate, plasma glucose, plasma Cortisol and the rate pressure product (RPP) were markers of the stress response. ADP–induced platelet aggregation and the release products β‐thromboglobulin, serotonin and thromboxane 2 were measured in plasma before and during as well as for 3 days after surgery.
Thoracic epidural analgesia in aortocoronary bypass surgery I: haemodynamic effects
Authors: STENSETH R. , BJELLA L. , BERG E. M. , CHRISTENSEN O. , LEVANG O. W. , GISVOLD S. E.
Published: January 2009

Tachycardia and hypertension may cause myocardial ischaemia in patients with coronary heart disease going through major surgery. Thoracic epidural analgesia (TEA) has been reported to be beneficial in this situation.

The haemodynamic effects of TEA in aortocoronary bypass surgery were investigated in 30 male patients < 65 years old and with ejection fraction > 0.5. They were randomized into 3 groups: the high dose fentanyl (HF) group receiving high–dose fentanyl (55 μg kg‐1) anaesthesia, the HF + TEA group receiving the same fentanyl dose + TEA with 10 ml bupivacaine 5 mg ml‐1 followed by 4 ml every hour, and the low dose fentanyl (LF) + TEA group receiving low–dose fentanyl (15 μg kg‐1) anaesthesia + TEA. Haemodynamic parameters, the use of vasoactive and inotropic drugs and fluid balance were followed during the operation and for 20 h postoperatively.

Before bypass the only significant difference between groups was a higher mean pulmonary arterial pressure in the HF + TEA group and a lower systemic vascular resistance (SVR) in the LF + TEA group, both compared to the HF group. 89% of epidural group patients needed small doses of ephedrine whereas more HF group patients were given nitroglycerine. During bypass SVR and mean arterial pressure (MAP) were significantly higher and pump flow lower in the HF group compared to the LF + TEA group. More ketanserin to HF group patients and methoxamine to epidural group patients were given. After bypass heart rate increased in all groups. Lower MAP 0.5 h after bypass and higher filling pressures in the early post bypass period in the epidural groups, most pronounced in the HF + TEA group, were noted. More propranolol, nitroglycerine and sodium nitroprusside were given to patients in the HF group. No difference in intraoperative fluid balance between groups was seen.

Our results suggest more easy control of perioperative hypertension and tachycardia with TEA. This was achieved without haemodynamic side effects of clinical importance.
Thoracic epidural analgesia in aortocoronary bypass surgery II: effects on the endocrine metabolic response
Authors: STENSETH R. , BJELLA L. , BERG E. M. , CHRISTENSEN O. , LEVANG O. W. , GISVOLD S. E.
Published: January 2009

Thoracic epidural analgesia (TEA) may offer haemodynamic benefits for patients with coronary heart disease going through major surgery. This may – in part – be secondary to an effect on the endocrine and metabolic response to surgery. We therefore investigated the effect of TEA on the endocrine metabolic response to aortocoronary bypass surgery (ACBS).

Thirty male patients (age < 65 years, ejection fraction > 0.5) were randomized into 3 groups; the HF group receiving a high dose fentanyl (55 μg–kg‐1) anaesthesia, the HF + TEA group with the same fentanyl dose + TEA with 10 ml bupivacain 5 mg ml‐1, followed by 4 ml every hour, and the LF + TEA group receiving fentanyl 15 μg kg‐1 + TEA. Adrenalin, noradrenalin, systemic vascular resistance (SVR), glucose, Cortisol, lactate and free fatty acids were followed during the operation and for 20 h postoperatively.

A significant increase in adrenalin, noradrenalin and SVR was found in the HF group whereas this increase was blocked in both epidural groups. An increase in glucose and Cortisol was noticed in all groups, but the increase was delayed in the epidural groups.

Our results suggest that a more effective blockade of the stress response during ACBS is obtained when TEA is added to general anaesthesia than with high dose fentanyl anaesthesia alone.
The redistribution of granulocytes following E. coli endotoxin induced sepsis
Authors: TOFT P. , LILLEVANG S. T. , TÖNNESEN E. , NIELSEN C. H. , RASMUSSEN J. W.
Published: January 2009

Infusion of endotoxin elicits granulocytopenia followed by increased numbers of granulocytes in peripheral blood. The purpose of this study was to investigate the redistribution and sequestration of granulocytes in the tissues following E. coli endotoxin induced sepsis. From 16 rabbits granulocytes were isolated, labelled with Indium and reinjected intravenously. Eight rabbits received an infusion of E. coli endotoxin 2 μg kg‐1while eight received isotonic saline. The redistribution of granulocytes was imaged with a gamma camera and calculated with a connected computer before and 2 and 6 hours after infusion of endotoxin or saline. Serum Cortisol and interleukin–lβ were measured. In another seven rabbits, respiratory burst activity and degranulation of granulocytes were measured prior to and from 5 min to 6 hours after infusion of E. coli endotoxin 2 μg kg‐1BW. Following infusion of endotoxin, the number of granulocytes in peripheral blood decreased from 2.44 to 0.064 times 10 1‐1two hours later. Within 5 min after infusion the overall oxidative burst of the peripheral blood granulocytes was increased and the granularity had decreased. Serum Cortisol and interleukin–lβ increased significantly. The radioactivity of labelled cells in the bone marrow and spleen decreased to 83.1% and 91.6% of initial values. At the same time there was a transient sequestration of labelled granulocytes in the lungs reaching 117.6% of initial values. The radioactivity of the liver increased continuously to 118.4%. The results indicate that endotoxin induces an efflux in activated granulocytes from peripheral blood, bone marrow and spleen to the lungs and liver. The sequestration of granulocytes may contribute to the development of ARDS and liver failure in sepsis.
Effects of propofol and thiopentone on polymorphonuclear leukocyte functions in vitro
Authors: SKOUTELIS A. , LIANOU P. , PAPAGEORGIOU E. , KOKKINIS K. , ALEXOPOULOS K. , BASSARIS H.
Published: January 2009

Anaesthetic agents may impair host defense mechanisms including polymorphonuclear leukocyte (PMNL) function.

We have studied the effects of thiopentone and propofol in low (thiopentone 10 mg/L, propofol 2 mg/1) and high (thiopentone 40 mg/L, propofol 6 mg/L) clinically relevant concentrations on PMNL adherence, chemotaxis, phagocytosis and killing in vitro.

The results demonstrated that thiopentone in both concentrations significantly decreases all PMNL functions tested and had a direct influence on the PMNLs in terms of their chemotactic response. In contrast, propofol decreases significantly only PMNL chemotaxis but not adherence, phagocytosis and killing. The effect of propofol was not attributable to the lipid carrier vehicle, as Intralipid with same formulation had no effect on PMNL function.
Acid aspiration syndrome prophylaxis in gynaecological and obstetric patients A Norwegian survey
Authors: SOREIDE E. , HOLST–LARSEN H. , STEEN P. A.
Published: January 2009

Clinical practice and attitudes of Acid Aspiration Syndrome (AAS) prevention in connection with gynaecological and obstetric surgery were surveyed in all Norwegian departments of anaesthesia. General anaesthesia with rapid–sequence intubation using succinylcholine and cricoid pressure was the preferred method for all emergency surgery, except Caesarian section (C–section) where 58% of the departments reported use of spinal or epidural anaesthesia if time allowed for its use. Chemoprophylaxis was more often used before emergency C–section (60%) than before emergency gynaecological surgery (14%), and mostly consisted of the antacid sodium citrate given alone. Seventy–six percent of the departments used mechanical emptying of the stomach before emergency gynaecological surgery and 44% before emergency C–section. While all responders considered recent intake of a “light breakfast” in an elective patient to be a risk factor of AAS indicating delay of surgery or use of specific precautions like regional anaesthesia, rapid–sequence intubation, or chemoprophylaxis, 52–72% of the responders considered obesity, dyspepsia, recent water intake, smoking or use of chewing gum to be risk factors as well. We think this survey demonstrates a need for consensus discussions of AAS prophylaxis.
Serum Potassium during Regional Anaesthesia with special reference to the effects of adrenaline
Authors: LÖFGREN A
Published: January 2009

Abstract: Hypokalaemia may occur in connection with regional anaesthesia. The main purpose of this thesis was to: (1) Evaluate the effect of some major forms of regional anaesthesia on the serum potassium (S–K) level. (2) Determine whether the response to adrenaline with regard to the S–K level is different during and after surgery compared to a plain experimental situation and, if so, decide if this can be explained by an altered responsiveness in the β–adrenoceptors. (3) Study ECG disturbances attributable to adrenaline and to hypokalaemia caused by the local anaesthesia. (4) Find out whether differences in health status and medication constitute risk factors in developing marked preoperative changes in the S–K level.

Ninety–seven patients and 10 volunteers participated in the studies. Local anaesthetics with and without adrenaline were used. Epidural anaesthesia using mepivacaine or bupivacaine and field block for inguinal hernia surgery with prilocaine were studied in relation to surgery. Intercostal nerve block with bupivacaine or prilocaine for postoperative pain relief after cholecystectomy and in volunteers were also studied. Data from 150 other patients were collected to evaluate S–K changes in the preoperative period.

Local anaesthetics with adrenaline caused hypokalaemia, but it was not possible to predict the hypokalemic effect from one type of nerve block to another. During surgery under local anaesthesia, surgical stress aggravated the hypokalaemia from exogenous adrenaline. The hypokalemic effect of marcaine–adrenaline was nearly abolished during intra–abdominal surgery under general anaesthesia, but it was intensified during recovery after cholecystectomy. No major arrthythmias were caused by the local anaesthetics with or without adrenaline. Preoperative S–K changes, with increases occurring as frequently as decreases, of 0.4 mmol/1 occurred in one third of the patients.

It is concluded that local anaesthetics with adrenaline cause a decrease in the S–K concentration and minor ECG disturbances. The hypokalemic effect of local anaesthesia might be intensified during postoperative recovery but reduced during surgery under general anaesthesia. The intra–operative lack of a hypokalemic effect caused by adrenaline could partly be explained by a reduced responsiveness in the β2–adrenoceptors. The preoperative changes in S–K can be explained only to a minor extent by the health status and medication of the patients.
Muscle relaxants in renal disease*
Authors: HUNTER J. M.
Published: January 2009

The use of neuromuscular blocking drugs during anaesthesia for patients with chronic renal failure is discussed. The disadvantages of the older non‐depolarizing agents, such as tubocurarine, alcuronium, and pancuronium, are outlined, as are the significant benefits of the use of atracurium or vecuronium in these patients. Preliminary reports on the new non‐depolarizing drugs, pipecuronium, mivacurium, doxacurium, and rocuronium are also noted.
Adverse reaction to neuromuscular blockers: frequency, investigation, and epidemiology
Authors: WATKINS J.
Published: January 2009

A survey is presented of neuromuscular drug involvement in 590 clinically severe anaphylactoid reactions (grades II‐IV) reported to a Sheffield laboratory from 1988 to the end of 1992 from hospitals throughout the UK. Despite advances in patient monitoring and newer drugs, the reporting frequency and individual drug involvement were remarkably similar to those of a previous report from the laboratory in 1988. The highly immunogenic drug suxamethonium still predominated (48% of reports), but there was now much reduced use of the similarly immunogenic drug, alcuronium. The incidence of reactions to vecuronium and atracurium remained similar (12% and 18% reports, respectively) and acceptable to the anaesthetist. However, in choosing drugs for individual patients, the anaesthetist may wish to note that vecuronium reactors mainly showed bronchospasm, and atracurium reactors hypotension. By a systematic laboratory investigation, based on measurement of plasma tryptase and urinary methylhistamine, reaction mechanisms were assessed in 53 reactions. Despite their overall clinical similarity, analysis revealed that only one reaction in three was likely to be due to IgE‐mediated anaphylaxis (Type 1). Not only was suxamethonium the most frequently reported drug, but in this study 11 reactions were identified as Type 1 response: no allergic reactions were identified for either vecuronium or atracurium, although single cases were identified for alcuronium, gallamine, and tubocurarine, with two unidentified. The remaining reactions were judged to be non‐immune, although most involved mast cell degranulation. These reactions were no less hazardous than Type 1 reactions (one death), and two deaths were recorded. The importance of laboratory investigation as a feature of postreaction care is emphasized.
Ventilation and neuromuscular blocking drugs
Authors: ERIKSSON L. I.
Published: January 2009

Ventilatory failure after administration of neuromuscular blocking agents is an important factor in anaesthesia‐related perioperative morbidity and mortality. Improved knowledge and new monitoring methods may avoid ventilatory failure caused by incomplete recovery of neuromuscular function in the postoperative period. Central respiratory muscles are less sensitive than, and their time course of neuromuscular block is different from those of, pharyngeal muscles and those of the upper airway. Differences in potency and time course of neuromuscular block may lead to incorrect assessment of ventilatory function during onset and recovery. Even if recovery of the mechanical adductor pollicis train‐of‐four (TOF) response to a ratio of 0.70 has previously been associated with adequate ventilatory capacity, it is now shown that hypoxic ventilatory responses may be markedly reduced despite adequate respiratory force at a TOF ratio of 0.70. Hence, partial paralysis may interfere with ventilatory regulation in hypoxaemia. Consequently, monitoring neuromuscular function by peripheral nerve stimulation in one muscle yields limited information about total ventilatory capacity, especially the function of the upper airway and ventilatory regulation. Therefore, neuromuscular monitoring should be used with caution during recovery and should always be combined with bedside clinical tests if possible.
Plasma cholinesterase and abnormal reaction to succinylcholine: twenty years' experience with the Danish Cholinesterase Research Unit
Authors: Jensen F. S. , Viby‐Mogensen J.
Published: January 2009

For more than 20 years, the Danish Cholinesterase Research Unit (DCRU) has collected information about patients showing an abnormal response to succinylcholine.

The purpose of this study was, on the basis of the 20 years' experiences with the Unit, to evaluate our clinical findings in patients referred because of prolonged response following succinylcholine. Also, we wanted to evaluate the results of our prospective controlled studies of the effect of succinylcholine in patients with normal and abnormal plasma cholinesterase genotypes.

An explanation for the apparent abnormal response to succinylcholine was found in 61.1% of the 1,247 patients referred to the Unit. Of the 1,247 patients, 28.5% were genotypically normal and 46.5% had an abnormal genotype. In the remaining 24.9% of the patients, the genotype could not be established. The time to sufficient recovery of neuromuscular function following succinylcholine 1.0–1.5 mg kg‐1was 15–30 min in patients heterozygous for one abnormal gene, 35–45 min in patients heterozygous for two abnormal genes and 90–180 min in patients homozygous for the atypical gene. Patients with two newly discovered genotypes (AK (5 patients) and AH (1 patient)) showed slightly prolonged (20 min) and markedly prolonged (90 min) duration of action of succinylcholine, respectively.

Our results indicate that it is a problem for many anaesthetists to correctly diagnose a prolonged response to succinylcholine. We therefore urge the anaesthetist always to use a peripheral nerve stimulator when faced with a case of apparent abnormal response to succinylcholine.
Effect of dextran on plasma tissue plasminogen activator (t‐PA) and plasminogen activator inhibitor‐1(PAI‐1) during surgery
Authors: Eriksson M. , Saldeen T.
Published: January 2009

Dextran is known to increase the plasminogen activation rate in vitro and to decrease the α2‐antiplasmin activity.

We decided to explore the effect of dextran on plasma tissue plasminogen activator (t‐PA) and plasminogen activator inhibitor‐1(PAI‐1) during surgical trauma.

Thirty‐one patients undergoing elective surgery were given 500 ml of 6% dextran 70. Another nine patients serving as controls were given 500 ml of a glucose‐electrolyte solution. The activities of t‐PA and PAI‐1during surgery were determined, as was the concentration of t‐PA antigen.

PAI‐1activity was decreased by 19% after infusion of 250 ml of dextran. After 500 ml, the activity was reduced by 22% (both P<0.05). The activity of t‐PA was increased by 43% and 29% (both P<0.05) and the antigenic amount of t‐PA was increased by 18% and 15% (both P<0.05) after infusion of 250 ml and 500 ml of dextran, respectively. No changes in these variables were observed in the control patients.

It is concluded that infusion of dextran promotes fibrinolysis by enhancing plasminogen activation in patients subjected to trauma. Since elevated levels of PAI‐1prior to surgery are known to predispose to deep vein thrombosis, which may form already during the operation, the effect of dextran on PAI‐1described here may explain its clot preventing properties.
Topical ketamine inhibits albumin extravasation in chemical peritonitis in rats
Authors: Hirota K. , Zsigmond E. K. , Rabito S. F.
Published: January 2009

Background. As ketamine has local anaesthetic actions and local anaesthetics are known to have anti‐inflammatory effects, ketamine could be expected to be an anti‐inflammatory agent. Here we sought to determine whether ketamine is indeed anti‐inflammatory in chemical peritonitis induced by HC1 in rats.

Methods. Peritonitis was elicited by applying 0.02 M HCI on the surface of the cecum or appendix and quantified by measuring the extravasation of intravenously injected Evan's Blue bound to albumin extracted from those tissues. Three experimental sets were performed. In the first set, four groups of 10 rats each received: 1%, 2%, and 4% ketamine and 1% lidocaine. In the same animal, before induction of peritonitis one area was topically pre‐treated with 0.9% saline (control site) and another area was topically pre‐treated with 1%, 2% or 4% ketamine or 1% lidocaine (experimental site). In the second set, two groups of 10 rats each received: 2% ketamine or 1% lidocaine. Ten min after the induction of peritonitis, the control site was topically treated with 0.9% saline, while the experimental site was treated with 2% ketamine or 1 % lidocaine. In the third set 20 rats, divided into two groups, were pre‐treated either with 2% S(+)ketamine or 2% R(‐)ketamine before the induction of peritonitis instead of the previously employed racemic version of the drug.

Results. Treatment of the cecum or appendix areas with ketamine or lidocaine before the induction of peritonitis decreased the extravasation of Evan's Blue‐albumin from 5.7±0.7 μg/100 mg tissue to 4.5±0.8, N.S. with 1% ketamine; from 5.9±0.8 to 4.1 ±0.7,P<0.01 with 2% ketamine; from 4.8±0.7 to 3.5±0.6,P<0.05 with 4% ketamine and from 5.9±0.6 to 3.6±0.8,P<0.01 with 1% lidocaine. Treatment of the areas of peritonitis with 2% ketamine or 1% lidocaine decreased the extravasation of Evan's Blue‐albumin from 5.6±0.5 μg/100 mg tissue to 4.4±0.6,P<0.05 and from 6.0±0.8 to 5.0+0.7,P<0.01. Administration of the isomer S(+)ketamine to colonic areas before the induction of peritonitis reduced the extravasation of Evan's Blue‐albumin from 6.5±0.7 μg/100 mg tissue to 4.1±0.6,P<0.01; while the isomer R(‐)ketamine was inactive.Conclusions.These results indicate that topically applied ketamine inhibited the development of chemical peritonitis. This action of racemic ketamine was due to the isomer S(+)ketamine.