bluuebunny/crossref_metadata_2025 huggingface dataset:
Can training improve the results with infrared tympanic thermometers?
Authors: PETERSEN M. H. , HAUGE H. N.
Published: January 2009

Background: Infrared tympanic thermometry (ITT) is a method for body temperature measurement. Correct measuring technique is said to be important to achieve good results with this method. The objective of this study was to investigate the accuracy and effect of training in the use of infrared tympanic therm‐omtry (ITT) on the measurement results.

Method: Nurses trained in the use of ITT, and nurses not trained performed measurement sequences on 65 patients: one rectal and two ITT measurements in each sequence.

Results: Mean rectal temperatures were significantly (P < 0.01) higher than with ITT (0.44±0.42 (SD)˚C for trained, 0.56±0.4 (SD)˚C for untrained). Coefficient of repeatability for ITT measurements was ±0.54˚C for trained nurses, and ±0.48˚C for untrained. With ITT temperatures adjusted upwards of 0.5˚C, the sensitivity of ITT for detecting fever as defined by rectal measurements would be 70% for trained, and 54% for untrained nurses. Repeatability and sensitivity for trained and untrained nuses were not significantly (P > 0.05) different.

Conclusion: Training had little effect on the accuracy of the measurements. According to our results, ITT is often unreliable and should be used with caution.
Anaphylactic shock following intravenous administration of lignocaine
Authors: ISMAIL K. , SIMPSON P. J.
Published: January 2009

A 26‐year‐old female, presenting for dental surgery, developed anaphylactic shock immediately after intravenous adminstration of lignocaine without preservative added to the propofol to alleviate pain during intravenous injection. We describe the clinical circumstances, the management and the investigations carried out to detect the cause.
Retardation of pain development: a case of recovery from congenital insensitivity to pain
Authors: ZHOU T.‐H. , REN X.‐H. , YIN D.‐L. , WU Y.‐L. , Li M. , Lu C.‐Z. , Wu D.‐C. , Wu Y.‐Q. , PENG Y.‐Q. , WANG Y.‐P. , MA L. , PEI G.
Published: January 2009

Congenital analgesia is a rare genetic disorder. We report here that a 12‐year‐old boy was able to recover from congenital insensitivity to pain. Neurological examinations revealed that there was a ‘stocking’ distribution of pain decrement on the lower extremities under the patient's knee joints. Magnetic Resonance Imaging (MRI) of his brain showed gyrus thinning with sulcus widening at both sides of the parietal lobe. Southern blot hybridization probed with cDNAs of various opioid receptors did not detect any significant abnormality. Our results suggest that this rare case may not be genetically determined.
Management of the difficult airway A case of failed fiberoptic intubation
Authors: WULF H. , BRINKMANN G. , RAUTENBERG M.
Published: January 2009

Background: Fiberoptic intubation is the current gold standard for the management of difficult intubation. Nevertheless, in rare circumstances even fiberoptic intubation fails.

Methods: We describe the case of a female patient suffering from neurofibromatosis Recklinghausen and a giant malignant schwannoma on the neck obstructing the pharynx and compromizing respiration. Based on the clinical presentation and the MRI findings, difficulties in airway management were anticipated and fiberoptic intubation of the awake patient was planned.

Results: After localizing the vocal cords it was not possible to advance the tube into the trachea due to the severe deviation of the glottis. A decision was made to cancel any further fiberoptic intubation attempts and a conventional tracheotomy was performed under local anaesthesia without problems.

Conclusion: This case illustrates that even awake fiberoptic intubation has its failure rate, due to inability to visualize the larynx, inability to advance the tube over the fiberscope (as in the present case), or inability to direct the tube towards the larynx. Due to the extreme deviation of the larynx other established techniques for difficult intubation were not deemed appropriate in this case. Therefore, weighing the risks and benefits, a decision was made to perfom a tracheotomy under local anaesthesia.
A rare case of a somatosensory evoked potentials recording during cardiopulmonary resuscitation
Authors: YANG L.‐C. , TAO‐CHEN L. , GALIK J.
Published: January 2009

Background: Neuronal damage is a possible complication of cardiac surgery. To reduce the potential risk of postoperative neurological deficit, the functional state of affectedcentral nervous system pathways is monitored intraoperatively by recording evoked potentials (EPs). Apart from animal research, there is little clinical evidence of EPs recordingduring cardiac arrest and cardio‐pulmonary resuscitation (CPR).

Methods: Both scalp (SCEPs) and spinal (SSEPs) short‐latency somatosensory EPs were recorded as the response to theelectrical stimulation of the right median nerve during mitral valve replacement surgery. Evoked potentials were recorded before, during, and after sudden ventricular fibrillationfollowed by CPR.

Results: Preoperative control recordings of both SCEPs and SSEPs were in the normal ranges. During the first 4 min of cardiac arrest and resuscitation, all SCEPs waves disappeared, while the spinal component of the SSEPs was still recognizable. After CPR, all waves of both EPs recordings recovered completely. The patient woke from anesthesia without neurological deficits.

Conclusions: As expected, scalp‐recorded EPs are more sensitive to the cardiac arrest than spinal EPs. Rapid and almost complete recovery of postoperative EPs, namely SCEPs, correlated well with normal neurological recovery.
Opioids in the management of pain during delivery
Authors: OLOFSSON CH.
Published: January 2009

Abstract: Labour and delivery involve severe pain for most women. The goal for pain treatment in obstetrics is to provide effective and safe analgesia during all phases of delivery. The ideal method for pain relief during delivery is not yet available. This thesis aims at studying some aspects of opioids in obstetric pain treatment with respect to analgesic efficacy and side‐effects, and to analyse pain during delivery from a neurobiological perspective.
Residual neuromuscular block is a risk factor for postoperative pulmonary complications A prospective, randomised, and blinded study of postoperative pulmonary complications after atracurium, vecuronium and pancuronium
Authors: BERG H. , VIBY‐MOGENSEN J. , ROED J. , MORTENSEN C. R. , ENGBÆK J. , SKOVGAARD L. T. , KRINTEL J. J.
Published: January 2009

Background: After anaesthesia involving pancuronium a high incidence of both residual neuromuscular block and postoperative pulmonary complications (POPC) has been reported. The aim of this study was to compare the incidence of POPC following the use of pancuronium, atracurium, and vecuronium, and to examine the effect of residual neuromuscular block on the incidence of POPC.

Methods: A total of 691 adult patients undergoing abdominal, gynaecological, or orthopaedic surgery under general anaesthesia were randomised to receive either pancuronium, atracurium, or vecuronium. Perioperatively, the response to train‐of‐four (TOF) nerve stimulation was evaluated manually. Post‐operatively, the TOF ratios were measured mechanomyograph‐ically, and through a 6‐day follow‐up the patients were examined for pulmonary complications.

Results: The incidence of residual block, defined as a TOF ratio <0.7, was significantly higher in the pancuronium group (59/226: 26%) than in the atracurium/vecuronium groups (24/450: 5.3%). In the pancuronium group, significantly more patients with residual block developed POPC (10/59: 16.9%) as compared to patients without residual block (8/167 4.8%). In the atracurium/vecuronium groups, the incidence of POPC was not significantly different in patients with (1/24: 4.2%) or without (23/426: 5.4%) residual block. Multiple regression analysis indicated that abdominal surgery, age, long‐lasting surgery, and a TOF ratio<0.7 following the use of pancuronium were potential risk factors for the development of POPC.

Conclusion: Postoperative residual block caused by pancuronium is a significant risk factor for development of POPC.
Aortic cross‐clamping influences regional net release and uptake rates of tissue‐type plasminogen activator in pigs
Authors: SEEMAN‐LODDING H. , HAGGMARK S. , JERN C. , TERN S. , JOHANSSON G. , WINSO O. , BIBER B.
Published: January 2009

Background: The key regulator of intravascular fibrinolysis, tissue‐type plasminogen activator (t‐PA), is released from a dynamic endothelial storage pool. The aim of the study was to investigate regional t‐PA net release and uptake rates in response to infra‐renal aortic cross‐clamping (AXC) and declamping (DC).

Results: Prior to AXC, we found a high net release rate of total t‐PA across the preportal vascular bed (1700 ng.min‐1, P < 0.001), and a high hepatic net uptake (4900 ng.min‐1, P < 0.001), while coronary and pulmonary t‐PA net fluxes were small and variable. AXC per se did not induce significant alterations in net fluxes of t‐PA. Following DC, preportal and coronary net releases of total t‐PA increased (to 2900 ng · min‐1 and 60 ngemin‐1, respectively). Despite an increase in hepatic net uptake of total t‐PA (to 6100 ng.min‐1) after DC, a significant increase in hepatic venous total t‐PA occurred.

Methods: Anesthetized pigs were studied during 5 min of AXC, followed by a 35‐min declamping (DC) period. Arterio‐venous concentration gradients of total and active t‐PA, as well as respective plasma flows, were simultaneously obtained across the preportal, hepatic, coronary and pulmonary vascular beds. Plasma levels of total t‐PA (ELISA with purified porcine t‐PA as standard), and active t‐PA (spectrophotometric functional assay) were determined.

Conclusions: The release and uptake of t‐PA is indicated to be dynamic and organ‐specific. DC induces an acute profibrinolytic reaction in preportal organs. The high hepatic t‐PA uptake capacity restricts preportal profibrinolytic events to affect the systemic circulation.
Mapping of punctuate hyperalgesia around a surgical incision demonstrates that ketamine is a powerful suppressor of central sensitization to pain following surgery
Authors: STUBHAUG A. , BREIVIK H. , EIDE P. K. , KREUNEN M. , Foss A.
Published: January 2009

Background:Tissue injury induces central sensitization in the spinal cord dorsal horn neurons via mechanisms involving N‐methyl‐D‐aspartate (NMDA) receptors, leading to secondary hyperalgesia. Using punctuate mechanical hyperalgesia as a measure of central sensitization, we examined whether induction and maintenance of central sensitization after surgery could be prevented by a low‐dose infusion of the NMDA‐receptor antagonist ketamine.

Results:The area of punctuate mechanical hyperalgesia was significantly reduced in the ketamine group 1, 3 and 7 d after the operation (P< 0.01–0. 001). “Wind‐up pain” was also reduced by ketamine (P< 0.05). PCA morphine consumption and pain intensity (visual analogue scale) differed between groups only during the first hours after surgery, in favour of ketamine. The ketamine patients scored significantly higher on a global satisfaction score. Side‐effects were most frequent in the placebo group.

Conclusion:Low‐dose i.v. infusion of ketamine during and after surgery reduces mechanical punctuate hyperalgesia surrounding the surgical incision. These results indicate that blockade of NMDA receptors prevents the central sensitization caused by nociceptive input during and after surgery.

Methods:Twenty living kidney donors were included in a randomized, double‐blind, parallel, two‐group study. Before start of surgery 10 patients received an i.v. bolus of racemic ketamine 0.5 mg · kg‐1, followed by a continuous i.v. infusion of ketamine 2 μg‐kg‐1‐min‐1for 24 h, thereafter 1 μg.kg‐1min‐1for another 48 h. The control group received placebo bolus and infusion. A standard general anaesthesia including fentanyl was used. Patient‐controlled (PCA) i.v. morphine was used for postoperative analgesia. Punctuate mechanical hyperalgesia and temporal summation of mechanical stimuli causing “wind‐up pain” were measured using von Frey filaments.
Endogenous nitric oxide in the airways of different animal species
Authors: KHEDIN U. , RÖKEN B. O. , NYMAN G. , FROSTELL C. , GUSTAFSSON L. E.
Published: January 2009

Background: High amounts of endogenous nitric oxide (NO) have been demonstrated in the human upper airway, but the role of nasal NO is still unclear. The present study aims to describe nasal NO excretion in different animal species with special living conditions or anatomy.

Methods: Domestic animals (horse, cow, pig, sheep, dog, cat) and zoo‐animals (Rhesus monkey, chimpanzee, gorilla, elephant, fur seal, alpaca, yak, dolphin, camel, capybara, bear, tiger, wolf, giraffe, alligator, Harris' hawk, kangaroo) were studied awake, resting or anaesthetised. NO concentrations were measured by chemiluminescence using different analysers and techniques, including measurements on mixed exhaled air, during continuous or intermittent gas sampling, and on single breaths.

Results: Rhesus monkeys (number of individuals N=5) and pigs (N=2) were compared and displayed quite different excretion patterns. Allowing NO to accumulate in the nose during timed occlusions yielded peak concentrations in monkeys of 0.46‐CO.07 parts per million (ppm, meanzSEM), 0.590.08 ppm, 0.700.08 ppm and 1.020.05 pprn NO after 15, 30, 60 and 120 s of occlusion. In pigs, 0.012–0.021 ppm NO were recorded, independent of occlusion time. The chimpanzee was similar to the Rhesus monkey and the highest NO value, 2.9 ppm, was recorded after 4–5 min of occlusion. In single breaths from 3 elephants 0.031–0.082 ppm, from 1 gorilla 0.029 ppm, and from 1 chimpanzee 0.0690.003 pprn NO (8 observations) were recorded.

Conclusions: We found considerable species difference in nasal NO excretion with pronounced amounts only in primates and elephants. The physiological implications of these findings remain to be defined.
Comparison of inhalation inductions with xenon and sevoflurane
Authors: NAKATA Y. , GOTO T. , MORITA S.
Published: January 2009

Background: Xenon is an odorless gas with low blood‐gas solubility coefficient and without occupational and environmental hazards. This investigation was performed to evaluate the speed of induction, and respiratory and cardiovascular reactions to inhalation induction with xenon compared to an equianesthetic concentration of sevoflurane.

Results: Compared to equianesthetic sevoflurane, xenon produced a faster induction of anesthesia (14759 versus 71221 s, respectively) with smaller decreases in respiratory rate, tidal volume and minute ventilation. Both agents showed comparable cardiovascular stability and oxygen saturation during induction. One patient in the sevoflurane group had breath‐holding and movements of extremities and another had only breath‐holding. No patients in the xenon group experienced any complications.

Conclusion: Xenon produced a faster induction of anesthesia without any complications than sevoflurane. Xenon had smaller decreases in tidal volume and respiratory rate during induction than sevoflurane. Xenon might offer an alternative to sevoflurane for an inhalation induction.

Method Twenty‐four adult ASA 1–2 patients premedicated with 0.05 mg/kg of midazolam were instructed to take vital capacity breaths of 1 minimum alveolar concentration (MAC) of either xenon or sevoflurane until they lost consciousness. Induction time, total ventilatory volume, tidal volume, respiratory rate, minute ventilation, end‐tidal MAC fraction, cardiovascular parameters and oxygen saturation were recorded. The patients were interviewed on the following day to evaluate their acceptability rating of the inhalation inductions.
Laryngeal mask bite blocks ‐ rolled gauze versus Guedel airway
Authors: KELLER C. , SPARR H. J. , BRIMACOMBE J. R.
Published: January 2009

Background: Biting on the silicone tube and pilot balloon of the laryngeal mask airway (LMA) may obstruct or damage them with the teeth and a bite block is recommended. The recommended bite block is a wad of gauze swabs rolled into a cylindrical shape and placed alongside the LMA. It is considered that this avoids irritating the posterior pharyngeal wall and damage to teeth whilst supporting the LMA tube when taped to it. The Guedel airway is commonly used as a bite block with the tra‐cheal tube and many anaesthetists also use it with the LMA. The aim of the following study was to compare rolled gauze swabs with a Guedel airway as a bite block for the LMA.

Methods: We compared the Guedel airway with rolled gauze swabs as a bite block for the laryngeal mask airway (LMA) in 120 ventilated patients in whom cuff pressures were limited to 5.87 kPa (60 cm H20) and anaesthesia management was standardised.

Results: In the Guedel airway group, there was a higher incidence of ventilatory problems (0 vs 4, P < 0.05), bleeding (0 vs 8, P < 0.01), hoarseness (0 vs 4, P0.05) and sore throat (2 vs 12, P < 0.01).

Conclusion: 1. The Guedel airway is an unsuitable bite block for the LMA. 2. Cuff pressure limitation is compatible with adequate ventilation. 3. The combination of LMA and Guedel airway probably prevents either from sitting in the correct anatomical position.
Autoregulation and vasodilator responses by isoflurane and desflurane in the feline renal vascular bed
Authors: SUNDEMAN H. , BIBER B. , RANER C. , WINSÖ O.
Published: January 2009

Background: Inhalational anesthetics have agent‐specific effects on the renal circulation. This study investigated renal vasodilator responses produced by either autoregulation, 0.8% isoflurane (ISO) or 3.5% desflurane (DES).

Methods: We measured systemic mean arterial pressure (MAP‐SYST; axillary artery), renal blood flow (QREN; perivascular ultrasound) and central venous pressure (CVP) in normoventilated cats (n=8) during basal chloralose anesthesia (control) and after the addition of IS0 and DES. Renal mean arterial pressure (MAPREN) was controlled by an aortic clamp. QREN was measured at pre‐set MAPREN levels of 50, 70 and 90 mmHg. Renal vascular resistance (RREN) was derived.

Results: When MAPREN was artificially restrained from 13325 mmHg to 90 mmHg during control, RREN decreased by 35% and no significant change in QREN was observed, reflecting an intact autoregulation. RREN levels during IS0 or DES at stages with unrestrained MAPREN (9526 and 10229 mmHg, respectively), were not significantly different from RREN at 90 mmHg during control. When MAPREN was artificially decreased below 90 mmHg, QMN decreased in a similar fashion among control and ISO/DES sequences. The autoregulatory capacity was not significantly different among these sequences. Between 90–70 mmHg, the autoregulatory capacity was reduced and not demonstrable below 70 mmHg.

Conclusion: The renal autoregulatory capacity was not attenuated by either IS0 or DES. These agents produced equipotent renal vasodilation, which was not more powerful than that produced by autoregulation alone. The renal vasorelaxant effects of IS0 and DES may therefore to a substantial extent be attributable to autoregulation.
Vectorcardiographic changes during laparoscopic cholecystectomy may mimic signs of myocardial ischaemia
Authors: GANNEDAHL P. , ODEBERG S. , LJUNGQVIST O. , SOLLEVI A.
Published: January 2009

Background: Laparoscopic surgery involves the use of intra‐ab‐dominal carbon dioxide insufflation (pneumoperitoneum). The increased intra‐abdominal pressure causes marked haemodyn‐amic changes, which may influence electrocardiographic monitoring. The aim of the present study was to elucidate the influence of pneumoperitoneum on vectorcardiographic recordings.

Methods: Vectorcardiographic changes (QRS vector difference= QRSVD, QRS loop area, QRS magnitude, ST vector magnitude, spatial ST vector change) were recorded continuously applying computerized vectorcardiography in 12 anaesthetised cardio‐vascularly healthy patients, scheduled for laparoscopic cholecystectomy.

Measurements were made before and during pneumoperitoneum in three different body positions (supine, Trendelenburg and reversed Trendelenburg), also employing transesophageal echo‐cardiography and invasive blood pressure monitoring. Results: Pneumoperitoneum significantly increased QRSVD, in parallel with an enlargement in loop area and magnitude. The magnitude was significantly increased in the transversal and frontal planes and there was a tendency to increase the magnitude in the sagittal plane. The increase in QRS‐VD reached levels previously associated with the development of myocardial ischaemia in patients with coronary artery disease. The ST‐variables were not changed by the pneumoperitoneum. The positional changes also influenced QRSVD significantly.

Conclusions: When computerized vectorcardiography is used for ischaemia monitoring during pneumoperitoneum, the ST‐variables seem reliable. However, vectorcardiographic QRS changes should be interpreted with caution, as the QRS alterations found during pneumoperitoneum mimic the changes seen during myocardial ischaemia.
Contradictory effects of dopamine at 32°C in pigs anesthetized with ketamine
Authors: ROSCHER R. , INGEMANSSON R. , WETTERBERG T. , ALGOTSSON L. , SJÖBERG T. , STEEN S.
Published: January 2009

Background: In critically ill patients who were surface cooled to 332C, we have observed that dopamine sometimes causes a substantial decrease in blood pressure. The present study was designed to compare the effects of dopamine in normothermia to those seen after surface cooling to 32C.

Methods: Seven pigs with a mean body weight of 21 kg were anesthetized with ketamine and muscle relaxation was induced with pancuronium. They were mechanically ventilated and given dopamine infusions (5 and 12 μg · kg‐1 min‐1) in normothermia and after surface cooling by cold water immersion to a central blood temperature of 320C (range 31.6–32.6C).

Results: In normothermia, dopamine at a dose of 5 μg · kg‐1 min‐1 increased mean arterial blood pressure (MAP) by 16% (P < 0.01) and cardiac output (CO) by 9% (P=0.051); at 12 μg kg‐1 min‐1 dopamine increased MAP by 26% (P < 0.01) and CO by 18% (P < 0.01). In hypothermia, MAP and CO did not change at an administration rate of 5 μg kg‐l · min‐1; at 12 μg · kg‐1 min‐1 CO was unchanged but MAP was significantly reduced by 15% (P < 0.01).

Conclusion: Dopamine increased CO and MAP in normothermia but not at 32C, where there was even a significant reduction of MAP in this porcine model.
Preoperative adjuvant epidural tramadol: the effect of different doses on postoperative analgesia and pain processing
Authors: Wilder‐Smith C. H. , Wilder‐Smith O. H. G. , Farschtschian M. , Naji P.
Published: January 2009

Background:Tramadol is an analgesic with combined opioid agonist and monoamine reuptake blocker properties, which may be useful as a perioperative analgesic and antinociceptive adjuvant.

Methods:The dose‐dependent effects of adjuvant preoperative epidural tramadol on postoperative analgesia (pain scores and patient‐controlled analgesia (PCA) use) and pain processing (heat pain thresholds) were prospectively studied in a double‐blind, randomised, placebo‐controlled 5‐day trial. Forty patients undergoing knee or hip surgery received anaesthesia with epidural lidocaine and epidural tramadol 20, 50 or 100 mg or placebo as a preoperative adjuvant. Postoperative analgesia was by intravenous PCA tramadol in all patients.

Results:Postoperative pain scores were similar in all groups. The time to first PCA use was shorter, the total dose and duration of PCA use greater, and side‐effects more common with 20 mg tramadol than with 100 mg or placebo (P<0.05). There were no differences in PCA doses required or side‐effects between the tramadol 100 mg and placebo treatment groups. Heat pain tolerance thresholds were increased with 100 mg tramadol at 48 h postoperatively compared to baseline and placebo (P= 0.01).

Conclusions:Preoperative adjuvant epidural tramadol does not improve postoperative analgesia after lidocaine epidural anaesthesia compared to placebo. Tramadol 20 mg results in anti‐analgesia and increased side‐effects. While tramadol 100 mg depresses postoperative pain‐processing, as measured by heat pain tolerance thresholds, this is not reflected in improved clinical pain measures.
Improved oxygenation using the prone position in patients with ARDS
Authors: Flaatten H. , Aardal S. , Hevrøy O.
Published: January 2009

Background: The prone position is known to increase oxygen uptake in patients with Adult Respiratory Distress Syndrome (ARDS).

Methods: In this clinical study from 1995–96, 14 ARDS patients with severe respiratory failure were treated for at least 1 h in the prone position. Responders, defined as having more than 10% increase in PaO2/FiO2 ratio from baseline after 1 h, were treated at least 6 h in the prone position.

Results: 11 patients responded during the first period of the prone position (primary responders). Two of the 3 non‐responders were turned prone a second time with increase in the PaO2FiO2 ratio (secondary responders). Mean PaO2FiO2 ratio (mean±SEM) in the supine position was 11.7±0.8 kPa, increasing to 16.6±1.8 kPa and 18.0±1.4 kPa after 1 and 6 h respectively (P=0.009). Mean time spent in the prone position was 69 h (range 3–256 h), and mean ventilatory time was 17 d (3–52 d). The mortality in this subgroup of our patients with ARDS was 42%, compared to 58% in 19 patients not turned prone in the same period.

Conclusions: The prone position together with PEEP appears to improve ventilation‐perfusion matching. The prone position is simple, effective and readily available and could be used early in most patients with ARDS.
Reduced CO2‐elimination during combined high‐frequency ventilation compared to conventional pressure‐controlled ventilation in surfactant‐deficient piglets
Authors: Lichtwarck‐Aschoff M. , Zimmermann G. J. , Erhardt W.
Published: January 2009

Background: Combined high‐frequency ventilation (CHFV) combines a conventional low‐frequency component with superimposed high‐frequency jet pulses. The intention is to overcome the limited CO2‐elimination of high‐frequency ventilation, and to decrease airway pressures and enhance hemodynamic performance by reducing the conventional component. The present study was performed to compare the effects of conventional continuous positive‐pressure ventilation (CPPV) on gas exchange, airway pressures and cardiac output to those of CHFV at matched minute volume (MV) and mean airway pressure (MPAW).

Methods: Sixteen anaesthetised piglets with lavage‐induced surfactant deficiency were ventilated with CPPV, with positive end‐expiratory pressure (PEEP) set to obliterate the lower inflection point of the inspiratory pressure‐volume loop. This setting was compared to CHFV during which 50% of the total MV was applied as superimposed jet pulses of 20 Hz at otherwise unchanged settings, and to CPPV at a PEEP level which was reduced (CPPVred) until MPAW matched MPAW during CHFV. Gas exchange, airway pressures and hemodynamics were measured after the ventilatory setting had been applied for 20 min.

Results: MPAW decreased from (median) 2.7 kPa with CPPV to 2.4 kPa with CHFV (P≤0.05). Peak inspiratory pressure was 3.6 kPa with CPPV, 3.2 kPa with CHFV, and 3.2 kPa with CPPVred (P≤0.05 for differences to CPPV), respectively. PaCO2 was comparable during CPPV (5.9 kPa), CPPVred and CHFVCO2, while it increased during CHFV (6.8 kPa, (P≤0.05)). Cardiac output did not differ significantly between the settings.

Conclusions: In the porcine lavage model, CO2‐elimination is reduced during CHFV compared to CPPV at matched minute volume. At matched mean airway pressure, CHFV fails to reduce peak inspiratory airway pressure and to improve hemodynamic performance compared to CPPV.
Plasma catecholamines and haemodynamic changes during pneumoperitoneum
Authors: Myre K. , Rostrup M. , Buanes T. , Stokland O.
Published: January 2009

Background: Insufflation of CO2 into the abdomen is used during all kinds of laparoscopic operations. The procedure elicits haemodynamic and hormonal responses. The reports on sympathetic responses to laparoscopic surgery have been conflicting. However, few studies have assessed sympathetic and haemodynamic responses to CO2 insufflation per se, eliminating possible effects of intubation, skin incision, surgical manipulation and positioning of the body. No studies have measured both venous and arterial plasma catecholamines, the latter being a more sensitive indicator of sympathetic activity. In the present study, we hypothesised an increased sympathetic activity during pneumoperitoneum and an association between haemodynamic and sympathetic responses.

Methods: Plasma adrenaline and noradrenaline from the radial artery and superior vena cava were measured immediately before and 10 min after abdominal insufflation of CO2 in 11 subjects. Haemodynamics were monitored invasively.

Results: During pneumoperitoneum arterial plasma noradrenaline increased from 155 (106, 209) pg/ml (median, lowest and highest quartile) to 283 (188, 378) pg/ml (P=0.003), while there were no changes in arterial plasma adrenaline. The calculated arterial‐superior vena cava difference in plasma noradrenaline did not change, indicating no increased sympathetic activity in the drainage area of the superior vena cava. Heart rate and cardiac index were unchanged, while total peripheral resistance and mean arterial blood pressure increased (P=0.002). The changes in arterial plasma noradrenaline were closely related to the changes in total peripheral resistance (r=0.69, P=0.01).

Conclusions: Plasma noradrenaline increases during pneumoperitoneum and is associated with changes in total peripheral resistance. Plasma adrenaline is unchanged and there is no evidence of increased sympathetic outflow to the drainage area of the superior vena cava. Thus, the increase in plasma noradrenaline may be due to more local activation of the sympathetic nervous system, probably somewhere from the drainage area of the inferior vena cava.
Effects of desflurane, sevoflurane and halothane on postinfarction spontaneous dysrhythmias in dogs
Authors: Novalija E. , Hogan Q. H. , Kulier A. H. , Turner L. H. , Bosnjak Z. J.
Published: January 2009

Background: Although desflurane (DES) and sevoflurane (SEV) have desirable features for use in patients with coronary artery disease, their effects on ventricular dysrhythmias following infarction are less known. We therefore examined the effects of DES and SEV upon spontaneous postinfarction ventricular dysrhythmias in dogs, and compared those effects to the well‐established antidysrhythmic effects of halothane (HAL) in this model.

Methods: After institutional approval, the left anterior descending coronary artery was ligated in 16 adult mongrel dogs during isoflurane anesthesia. All dogs developed acute myocardial infarction and severe ventricular tachydysrhythmias. Twenty‐two hours after infarction, dogs were anesthetized at 1.5 MAC with desflurane (10.8%) followed by sevoflurane (3.5%) in the treatment group (n=10), or halothane (1.3%) in the other group (n=6). Anesthetic gases were allowed to equilibrate for at least 20 min at each end‐tidal concentration. At this time, the ECG was recorded for 9 min and evaluated for the number of ventricular ectopic and sinoatrial beats and summed duration of ventricular tachycardia.

Results: DES and SEV reduced the average rate of total ventricular ectopic beats by 40 ±4% and 42 ±4%, respectively. HAL decreased total ventricular ectopic rate by 59 ±6% and 62 ±5% after durations of anesthesia comparable to DES and SEV, respectively. Decreases in dysrhythmia in the presence of DES and SEV were significantly smaller than those produced by HAL after a comparable total duration of anesthesia.

Conclusions: DES and SEV inhibit spontaneous postinfarction ventricular dysrhythmias, although attenuation of dysrhythmias was smaller than the inhibition during comparable doses of HAL.
Transient radicular irritation with intrathecal plain lignocaine
Authors: Henderson D. J. , Faccenda K. A. , Morrison L. M. M.
Published: January 2009

Background: The aetiology of the syndrome known as transient radicular irritation (TRI) has generated much interest.

Method: A 50‐year‐old woman had right knee arthroscopy performed under spinal anaesthesia with 1% plain lignocaine. Result: At home, on the night of the procedure, she was woken by severe, bilateral cramp‐like pain in both buttocks radiating to her thighs. Neurological examination of her lower limbs, the next morning, was entirely normal. The pain lasted for 36 h and a full recovery was made.

Conclusions: This case of transient radicular irritation occurred in a patient given 40 mg of subarachnoid lignocaine (the lowest dose of isobaric preservative‐free lignocaine reported thus far that has been associated with these symptoms). Her operation was performed in the supine position. The lack of confounding factors (hyperbaricity, high concentration solution, preservatives, lithotomy position) suggests lignocaine as a possible cause, yet current theories do not fully explain the aetiology of transient radicular irritation. Results from large‐scale epidemiological studies will hopefully provide insight into the cause of this problem.
Xylocain (Lidocaine, Lignocaine), its discovery and Gordh's contribution to its clinical use
Authors: HOLMDAHL M. H:SON
Published: January 2009

Hans v. Euler, while investigating how genes and enzymes were chemically related in some chlorofylldefective mutants of barley, isolated gramme, an indole. Erdtman synthetized isogramine and found it to have weak anesthetic properties. He then together with Löfgren synthetized other amino‐amides, but no one of them could compete with the existing local anesthetics of the ester‐type, derivatives of para‐aminobenzoic acid, e.g. procaine. Later Löfgren and Lundqvist followed up these studies and found an amid compound lidocaine (2‐dimethylaminoacet2, 6‐xylidide). Lidocaine represented such a significant advance over procaine in clinical tests preformed by T. Gordh that it was introduced for clinical use. It has now during a half century been the standard local anesthetic drug. All local anesthetics are neurotoxic in high enough doses. Xylocain ®, however, has had an excellent record of safety. Only during the last years have there been reports on possible toxic irritation and damage by Xylocain used for spinal anesthesia. The aetiology is still not clear. In this connection two early observations by Gordh and his coworkers are discussed.
Postural changes in respiratory function
Authors: REHDER K.
Published: January 2009

Changes in body position alters the functional residual capacity (FRC). Most anesthetics reduce FRC in the recumbent but not sitting position. Inspired gas distribution in anesthesia‐paralyzed subjects whose lungs are mechanically ventilated, is different from that in the awake state in all but the prone position. The function of the diaphragm is altered by postural changes. The pattern of motion of the diaphragm is different during mechanical ventilation than during spontaneous breathing. Also the end‐expiratory shape is affected by induction of anesthesia, but this shape change contributes little to the reduction of FRC. The distribution of pulmonary blood flow is determined not only by gravity, but also by an intrinsic non‐gravity dependent factor. These two factors can be additive in some positions but opposing in others.
Intraoperative monitoring with somatosensory evoked potentials in carotid artery surgery ‐ less reliable in patients with preoperative neurologic deficiency?
Authors: Linstedt U. , Maier C. , Petry A.
Published: January 2009

Background: In a retrospective analysis of intraoperative somatosensory evoked potential (SEP) results during carotid artery surgery we found some cases with postoperative neurologic deficits, surprisingly without significant SEP changes.

Methods: Median nerve SEP were monitored as usual. Indication for selective shunting was a complete loss of amplitude N20/P25 in the first period of the investigation, later on a 50% reduction, or a prolongation of the central conduction time (CCT) of about 1.5 ms after cross‐clamping. Anaesthesia was maintained with isoflurane in N2O/O2, fentanyl and atracurium.

Results: Over a 3‐year period 146 patients were monitored. Indications were: transient ischaemic attacks (TIA) (n=51), stroke (n=23), stroke with residuals (n=39), asymptomatical stenosis (n=29), subclavian steal syndrome (n=4). Twenty‐four patients received an intraluminal shunt following SEP alterations. Post‐operatively, 5 patients (3.4%) had symptoms of intraoperative brain ischaemia (stroke n=2, TIA n=3), 4 of them showing only minor intraoperative SEP alterations; 1 received a shunt because of CCT prolongation. Four of these 5 patients had cerebral neurologic deficiency preoperatively.

Conclusion: Since some authors have found a 100% sensitivity of intraoperative SEP, it is remarkable, that 1 patient with postoperative stroke and 3 patients with TIA had no significant SEP changes intraoperatively. We suppose there was an association with preoperative neurological deficits resulting from previous strokes. In such cases, regional critical ischaemia may apparently occur outside the sensory pathway monitored with SEP.
A comparison of the effects of fentanyl and propofol on left ventricular contractility during myocardial stunning
Authors: Ross S. , Munoz H. , Piriou V. , Ryder W. A. , Foex P.
Published: January 2009

Background: The intravenous anaesthetic propofol has been shown to possess free radical scavenging activity and calcium channel blocking effects in a number of in vitro models. We decided to compare the effects of propofol with those of fentanyl on myocardial contractility during and after ischaemia to determine whether propofol could protect the heart and improve recovery of ventricular contractile function in open‐chested dogs.

Methods: Twenty adult beagles were acutely instrumented, under halothane anaesthesia, to measure ECG; aortic, left ventricular pressures; cardiac output; coronary flow; and segmental lengths in the regions perfused by the left anterior and left circumflex coronary arteries. After surgery and a stabilisation period halothane anaesthesia was terminated and fentanyl (100 μg. kg‐1 bolus followed by 2 μ.kg‐1·min‐1 infusion; n=10) or propofol (5 mg. kg‐1 bolus followed by 0.3 mg· kg‐1 min‐1 infusion; n=10) anaesthesia commenced. After a stabilisation period the LAD coronary artery was occluded for 10 min and then reperfused for 3 h. Measurements were taken throughout the protocol.

Results: We found no significant difference in recovery of contractile function between propofol and fentanyl as assessed by normalised preload recruitable work area (50±10 vs 47±16%), normalised systolic shortening (36±12 vs 48±14%) and peak left ventricular dP/dt (1665±276 vs 1846±151 mmHg.s‐1) at the end of reperfusion.

Conclusion: We conclude that at the concentration used in this study propofol shows no improvement in contractility during “stunning” when compared to fentanyl.
Systemic oxygen uptake during experimental closed‐chest cardiopulmonary resuscitation using air or pure oxygen ventilation
Authors: Rubertsson S. , Karlsson T. , Wiklund L.
Published: January 2009

Background: Although clinical cardiopulmonary resuscitation always includes ventilation with pure oxygen, this kind of ventilation has been reported to be associated with worse neurological outcome than ventilation with air in experimental cardiopulmonary resuscitation (CPR). The aim of the present investigation was to compare the systemic oxygen uptake during experimental closed‐chest CPR including ventilation with pure oxygen or ambient air and, furthermore, to elucidate possible mechanisms of action in the regulation of pulmonary gas exchange.

Methods: In 24 anesthetized piglets, 2 min of induced ventricular fibrillation and no ventilation was followed by 10 min of closed‐chest CPR including i.v. administration of 0.5 mg adrenaline (at 8 min), and in one of the experimental groups alkaline buffer (at 5 min). The piglets were randomly divided into 3 groups: air ventilation during the entire CPR period with saline administration (n=8), air ventilation during the entire CPR period plus tris buffer mixture (n=8), and air ventilation for 3 min followed by 100% oxygen with saline administration (n= 8).

Results: In the group ventilated with air and treated with tris buffer mixture, cardiac output was significantly greater than in the group ventilated with pure oxygen. The arterial‐mixed venous oxygen content difference was approximately 25% greater with pure oxygen than with air ventilation; however, there was no difference in systemic oxygen uptake. Systemic oxygen uptake increased after administration of tris buffer mixture in the group ventilated with air.

Conclusions: Pulmonary hypoxic vasoconstriction appeared to be abolished during CPR including pure oxygen ventilation. Blood flow, not ventilation or pulmonary gas exchange, is the limiting factor during experimental closed‐chest CPR.
Extra protein loss not caused by surgical bleeding in patients with ovarian cancer
Authors: Rehm M. , Haller M. , Brechtelsbauer H. , Akbulut C. , Finsterer U.
Published: January 2009

Backround: Clinical experience in patients with ovarian cancer has shown special difficulties in maintaining cardiovascular stability during surgery.

Methods: To evaluate the causes for this observation, 15 patients with benign ovarian tumours (group I) and 13 patients with ovarian cancer (group II) were investigated perioperatively. Plasma volume (indocyanine green‐dilution technique), hae‐matocrit, plasma protein concentration, mean arterial pressure, heart rate, and central venous pressure were measured immediately before and after cytoreductive surgery.

Results: Normal values of blood‐, plasma‐, and red cell volume were determined preoperatively in both groups, and in relation to body surface area there were no intergroup differences of these parameters. In group I, the significant decrease in red cell volume of 313 ml postoperatively was compensated for by an increase in plasma volume of 371 ml (median values). In contrast to group I, the decrease in red cell volume of 328 ml in group II was not related to a significant increase in plasma volume, so that blood volume postoperatively was 483 ml lower than preoperatively, although the same standardized infusion regimen as in group I was applied. Patients of group II had a significantly higher loss of intravascular protein (49 g vs 13 g in group I), which left the intravascular space by another way than by surgical bleeding. This extra protein loss is termed Intraoperative Protein Shift (IPS).

Conclusion: IPS could be an important quantity in perioperative fluid balance. We assume that different surgical procedures predispose to occurrence of differing amounts of IPS.
Catheter‐related infections following axillary vein catheterization
Authors: Martin C. , Bruder N. , Papazian L. , Saux P. , Gouin F.
Published: January 2009

Background: The aim of this study was to determine the rate of infectious complications following axillary vein cannulation and a compare to that observed after internal jugular vein cathterization.

Methods: A prospective comparative open study was carried out to determine the rate of infectious complications related to the use of catheters inserted via the axillary vein or the internal jugular vein. During the study period all patients submitted to central venous catheterization were evaluated. A total of 141 patients entered and completed the study. Catheter insertion sites were either the axillary vein punctured in the axilla, or the internal jugular vein punctured using an anterior approach. Catheter tips were cultured using a quantitative technique. Clinical information pertaining to the analysis was prospectively collected.

Results: A total of 141 catheters from 141 patients entered was studied. Clinical characteristics and risk factors for catheter infection were similar in both groups. The incidence of catheter‐related infection (including catheter‐related sepsis, and bacteremia) was not different between the two groups (axillary vein: 8.1%; internal jugular vein: 7.6%). Catheter‐related bacteremia were seen at a rate of 3.7% in the internal jugular vein group and a rate of 1.6% in the axillary vein group (NS). The incidence of catheter colonization was similar in both groups (axillary vein: 14.5%; internal jugular vein: 11.4%).

Conclusion: Catheter‐related infection after axillary vein catheterization was similar to that observed after internal jugular vein catheterization. The chance of developing catheter‐related sepsis was less than 10% with either route when catheters were used for the treatment of severely ill patients.
Effects of anaesthesia based on high versus low doses of opioids on the cytokine and acute‐phase protein responses in patients undergoing cardiac surgery
Authors: Brix‐Christensen V. , Tønnesen E. , Sørensen I. J. , Bilfinger T. V. , Sanchez R. G. , Stefano G. B.
Published: January 2009

Background: Cardiac surgery with cardiopulmonary bypass (CPB) evokes a systemic inflammatory response involving the proinflammatory cytokines tumor necrosis factor‐α (TNFα), interleukin (iL)‐1, IL‐6, IL‐8 and anti‐inflammatory cytokines such as IL‐10. Like IL‐10, opioids downregulate the immune responses in vivo and in vitro, including the activity of the cytokine‐producing monocytes and granulocytes. The proinflammatory cytokines are potent inducers of the hepatic acute‐phase protein synthesis. The aim of the present study was to investigate if choice of anaesthesia, based on high‐dose opioids (fentanyl) versus low‐dose opioids influenced the release of IL‐6, IL‐8, and IL‐10. Secondly, it was investigated whether serum amyloid P‐component (SAP) is an acute‐phase protein in man such as C‐reactive protein (CRP), with which it is physically and structurally related.

Methods: Sixteen patients submitted to elective coronary artery bypass grafting (CABG) surgery were randomized to either low‐dose opioid anaesthesia consisting of thoracic epidural analgesia combined with inhalational anaesthesia (group I) or high‐dose fentanyl anaesthesia (group II). From each patient 18 blood samples were taken perioperatively. Cytokine analyses were performed with ELISA, CRP and SAP mere measured with rocket immunoelectrophoresis (REI).

Results: Surgery and CPB elicited a marked, transient and almost simultaneous proinflammatory and anti‐inflammatory cytokine response with no differences between the groups. The cytokine levels returned to preoperative levels 1–3 d after operation. Anaesthesia and surgery did not affect SAP plasma levels while patients showed a major increase in CRP concentrations preceding the cytokine responses.

Conclusion: CABG performed during two different anaesthetic techniques, high‐dose fentanyl versus low‐dose opioid anaesthesia, elicited a well‐defined cytokine response with minor variation in the time course of each cytokine. The cytokine production was not modified by type of anaesthesia. Finally, SAP is not an acute‐phase protein in men.