bluuebunny/crossref_metadata_2025 huggingface dataset:
Cesarean section under epidural ropivacaine 0.75% in a parturient with severe pulmonary hypertension
Authors: Olofsson CH. , Bremme K. , Forssell G. , Öhqvist G.
Published: August 2010

Pregnancy and delivery are a potentially lethal combination in a patient with primary pulmonary hypertension. There are controversies regarding mode of delivery. Cesarean section is considered to be associated with extensive perioperative risks. We report on a parturient with severe pulmonary hypertension who underwent a succesful semiemergent cesarean section on vital indication. Vaginal delivery was excluded since her cervix was too immature for succesful induction. This is the first reported case of its kind to receive an epidural anesthesia with ropivacaine with its potential advantage of a low cardiac toxicity. The epidural was slowly and carefully titrated to give a stable anesthesia with good quality.
Intrathecal clonidine does not reduce post‐spinal shivering
Authors: Jeon Y. T. , Jeon Y. S. , Kim Y. C. , Bahk J. H. , Do S. H. , Lim Y. J.
Published: August 2010

Background:  After general or epidural anesthesia, clonidine is known to be effective in suppressing established shivering. The aim of this study was to assess the preventive effect of intrathecal clonidine on post‐spinal shivering compared with intravenous (i.v.) clonidine.

Methods:  One hundred and fifty patients scheduled for orthopedic surgery were randomly allocated into three groups to receive either 1 µg/kg clonidine i.v. (IV group) or the same volume of isotonic saline (control and IT groups) at 5 min before spinal anesthesia. Spinal anesthesia was performed with 12–15 mg hyperbaric bupivacaine 0.5% plus either 1 ml of saline (control and IV groups) or 150 µg clonidine (IT group). Shivering was evaluated for a period of 90 min and graded as none, mild, moderate, and severe.

Results:  Twenty patients (40%) in the control group and 17 patients (34%) in the IT group showed shivering compared with four (8%) in the IV group. Patients with moderate‐to‐severe shivering were only seen in the control and IT group, and the maximal intensity of shivering was not different between the two groups. Patients in the IV group were significantly more sedated than the other groups.

Conclusions:  The intrathecal administration of clonidine 150 µg fails to prevent post‐spinal shivering; by contrast, we have confirmed that i.v. clonidine 1 µg/kg is an effective method to prevent shivering in patients undergoing spinal anesthesia for orthopedic surgery.
Effect of pulmonary artery pressure on extravascular lung water in an experimental model of acute lung injury
Authors: Colmenero M. , Pérez Villares J. M. , Fernández Sacristán M. A. , Garcia Delgado M. , Fernández Mondéjar E.
Published: August 2010

Background:  Lung edema can be influenced by hemodynamic changes in pulmonary circulation. The aim of this study was to evaluate, in an experimental model of acute lung injury, the effect on extravascular lung water (EVLW) of an increase in pulmonary artery pressure (Ppa) without changes in cardiac output and wedge pressure.

Methods:  Lung edema was produced by an intravenous oleic acid infusion in mixed‐breed pigs weighing 25–31 kg, which, after 20 min, were randomly assigned to a control group (100% FiO2) (n = 6) or a high Ppa group (21% FiO2) (n = 7). An increase in pulmonary artery pressure of at least 40% over baseline was produced in the high Ppa group by alveolar hypoxia. Hemodynamic, ventilatory and gas exchange parameters were collected at regular intervals. Pulmonary, wedge and capillary pressures were measured with a pulmonary artery catheter and the occlusion technique. EVLW was calculated gravimetrically.

Results:  At 240 min, both gravimetric‐measured EVLW and mean pulmonary artery pressures were significantly higher (P < 0.05) in high Ppa animals vs. controls (12.06 ± 4.21 vs. 7.98 ± 2.46 ml/kg and 39.0 ± 1.3 vs. 26.6 ± 4.7 mmHg, respectively). Cardiac output (6.8 ± 2.5 vs. 7.3 ± 1.3) and pulmonary wedge pressures (9.2 ± 1.7 vs. 9.4 ± 2.8 mmHg) were similar. A difference was detected in pulmonary capillary pressures [17.0 ± 3.3 (high Ppa) vs. 13.8 ± 2.7 mmHg (controls)] but did not reach statistical significance.

Conclusions:  In this model, an increase in pulmonary artery pressure by alveolar hypoxia produces an increase in extravascular lung water, probably related to changes in pulmonary capillary pressures.
The effect of propofol on actin, ERK‐1/2 and GABAA receptor content in neurones
Authors: Oscarsson A. , Juhas M. , Sjölander A. , Eintrei C.
Published: August 2010

Aim:  Interaction with the γ‐aminobutyric acid receptor (GABAAR) complex is recognized as an important component of the mechanism of many anaesthetic agents, including propofol. The aims of this study were to investigate the effect of propofol on GABAAR, to determine whether exposure of neurones to propofol influences the localization of GABAAR within the cell and to look for cytoskeletal changes that may be connected with activation, such as the mitogen‐activated protein kinase (MAPK) pathway.

Methods:  Primary cortical cell cultures from rat, with and without pre‐incubation with the GABAAR antagonist bicuculline, were exposed to propofol. The cells were lysed and separated into membrane and cytosolic fractions. Immunoblot analyses of filamentous actin (F‐actin), the GABAAβ2‐subunit receptor and extracellular signal‐regulated kinase‐1/2 (ERK‐1/2) were performed.

Results:  Propofol triggers an increase in GABAAR, actin content and ERK‐1/2 phosphorylation in the cytosolic fraction. In the membrane fraction, there is a decrease in GABAAβ2‐subunit content and an increase in both actin content and ERK‐1/2 phosphorylation. The GABAAR antagonist bicuculline blocks the propofol‐induced changes in F‐actin, ERK and GABAAβ2‐subunit content, and ERK‐1/2 phosphorylation.

Conclusion:  We believe that propofol triggers a dose‐dependent internalization of the GABAAβ2‐subunit. The increase in internal GABAAβ2‐subunit content exhibits a close relationship to actin polymerization and to an increase in ERK‐1/2 activation. Actin contributes to the internalization sequestering of the GABAAβ2‐subunit.
Use of the bispectral index to predict a positive awareness reaction to laryngeal mask airway–Fastrach insertion and intubation
Authors: Kocaman Akbay B. , Demiraran Y. , Yalcin Sezen G. , Akcali G. , Somunkiran A.
Published: August 2010

Aim:  To determine whether the bispectral index (BIS) can be monitored to predict and indicate an awareness reaction to laryngeal mask airway–Fastrach (LMA–Fastrach) insertion and intubation at BIS values between 40 and 60.

Methods:  Fifty‐one American Society of Anesthesiologists’ (ASA) class I or II status patients aged over 20 years were included in this study. Midazolam 0.1 mg/kg was given for pre‐medication, 30 min before induction. For induction, a 0.1‐μg/kg bolus injection of remifentanil was followed by infusion, and propofol was administered until the eyelash reflex disappeared; the infusion rate was adjusted to maintain BIS values between 40 and 60. Loss of the eyelash reflex, loss of response to verbal commands, yawning and total propofol consumption were recorded. Patients were tested for awareness twice at 1‐min intervals using the isolated forearm technique. The test was considered to be positive if the patient squeezed a hand when asked; after muscle relaxation, the patient was intubated and the test was repeated. In the recovery room and ward, patients were asked whether they could recall this event.

Results:  Seven patients tested positive: two following LMA–Fastrach insertion and the remaining five following intubation. None of the patients had recall.

Conclusion:  Awareness during anaesthesia may occur at BIS levels that indicate adequate anaesthesia, but this is not associated with recall of the events later.
Pre‐treatment with hyperoxia before coronary artery bypass grafting – effects on myocardial injury and inflammatory response
Authors: Karu I. , Loit R. , Zilmer K. , Kairane C. , Paapstel A. , Zilmer M. , Starkopf J.
Published: August 2010

Background:  In experimental studies, exposure to hyperoxia for a limited time before ischaemia induces a low‐grade systemic oxidative stress and evokes an (ischaemic) preconditioning‐like effect of the myocardium. We hypothesised that hyperoxia before cardioplegia could protect the myocardium against necrosis and stunning caused by ischaemia–reperfusion.

Methods:  Forty patients undergoing coronary artery bypass grafting were randomly exposed to an oxygen fraction of 0.4 or >0.96 in inspired air on an average of 120 min before cardioplegia. Blood for troponin I, creatine kinase‐MB, lactate, glutathione and interleukin‐6 was sampled from arterial and coronary sinus cannulae during 20 min of reperfusion. Additional arterial samples were drawn 60 min after declamping and in the first post‐operative morning. The cardiac index and right and left ventricular stroke work indices were measured before sternotomy and up to 12 h post‐operatively.

Results:  Troponin I, creatine kinase‐MB and lactate did not differ between the groups. Hyperoxic pre‐treatment had no impact on the post‐operative haemodynamic indices measured with the thermodilution pulmonary artery catheter. More oxidised glutathione was released in the hyperoxia group in the first minute of reperfusion (P = 0.015). Hyperoxic pre‐treatment abolished the myocardial release of interleukin‐6 during 20 min of reperfusion (P = 0.021 vs. controls). In the first post‐operative morning, interleukin‐6 was higher in the hyperoxia group [127.0 (86.0–140.0) vs. 85.2 pg/ml (66.6–94.5 pg/ml); P = 0.016].

Conclusions:  Exposure to >96% oxygen before cardioplegia did not attenuate ischaemia–reperfusion injury of the heart in patients undergoing coronary artery bypass grafting. The only potentially beneficial effect observed was the decreased transmyocardial release of interleukin‐6.
Comparison of electrical velocimetry and thermodilution techniques for the measurement of cardiac output
Authors: Zoremba N. , Bickenbach J. , Krauss B. , Rossaint R. , Kuhlen R. , Schälte G.
Published: August 2010

Aim:  To compare a new method of non‐invasive determination of cardiac output based on electrical velocimetry (EV‐CO) with invasive thermodilution methods.

Methods:  Fifty critically ill patients were enrolled into the study. EV‐CO was compared with cardiac output measured by a pulmonary artery catheter (PA‐CO) in one group (n= 25) and by a femoral artery catheter (PiCCO‐CO) in a second group (n= 25), by simultaneous measurements. Standard electrocardiography electrodes were used for non‐invasive measurements, and EV‐CO was calculated using the Bernstein–Osypka equation. The invasive measurements of PA‐CO and PiCCO‐CO were made by the injection of iced 0.9% saline and the recording of thermodilution curves.

Results:  The precision values of EV‐CO, PA‐CO and PiCCO‐CO measurements were ± 0.46 [95% confidence interval (95% CI), ± 0.06], ± 0.57 (95% CI, ± 0.09) and ± 0.48 l/min (95% CI, ± 0.08 l/min), respectively. The mean differences between EV‐CO and PA‐CO or PiCCO‐CO were –0.05 ± 0.71 and 0.22 ± 0.78 l/min, respectively. The lower and upper limits of agreement for the comparison of EV‐CO with PA‐CO were −1.47 and 1.37 l/min (95% CI, ± 0.25 l/min), respectively. In the comparison of EV‐CO and PiCCO‐CO, lower and upper limits of –1.34 and 1.78 l/min (95% CI, ± 0.27 l/min) were found. The percentage errors between EV‐CO and PA‐CO or PiCCO‐CO were 26.5% and 26.4%, respectively.

Conclusions:  The values of cardiac output were statistically comparable between the groups. Therefore, electrical velocimetry is a suitable method to evaluate haemodynamic variables with clinically acceptable accuracy.
Decision making in a life‐threatening cerebral condition: a comparative study of the ethical reasoning of intensive care unit physicians and neurosurgeons
Authors: Rydvall A. , Bergenheim T. , Lynöe N.
Published: August 2010

Aim:  To study the support for the arguments of neurosurgeons and intensive care unit (ICU) physicians for and against life‐sustaining treatment of critically ill patients, and whether neurosurgeons are less inclined to emphasize quality‐of‐life aspects than ICU physicians.

Methods:  A postal questionnaire was sent to a random sample of ICU physicians in Sweden (n= 298) and all neurosurgeons in Sweden (n= 112). The respondents evaluated and prioritized different arguments for and against withholding neurosurgery, withdrawing life‐sustaining treatment and providing drugs which may hasten death.

Results:  The response rate was 62.5% for neurosurgeons and 73.5% for ICU physicians. Quality‐of‐life aspects were stressed as an important argument by the majority of both neurosurgeons and ICU physicians (76.8% vs. 54.0%); however, significantly more neurosurgeons regarded this argument as the most important (P < 0.001). A minority in both groups, although more ICU physicians (P < 0.001), supported a patient’s previously expressed wish of not ending in a persistent vegetative state as the most important argument. As the case clinically progressed, a consensus regarding the arguments for decision making evolved.

Conclusions:  No support was found for the hypothesis that ICU physicians care more about the quality of life of a severely ill patient. Indeed, significantly more neurosurgeons emphasized the quality‐of‐life aspects in this particular setting. Compared with neurosurgeons, significantly more ICU physicians considered the patient’s own wishes to be important.
Changes in heart rate variability may reflect sympatholysis during spinal anaesthesia
Authors: Hanss R. , Ohnesorge H. , Kaufmann M. , Gaupp R. , Ledowski T. , Steinfath M. , Scholz J. , Bein B.
Published: August 2010

Background:  To investigate if changes in low‐to‐high frequency ratio (LF/HF), low frequency (LF) and high frequency (HF) heart rate variability reflect autonomic regulation during spinal anaesthesia (SA) in pregnant women scheduled for elective Caesarean section.

Methods:  Prospective clinical trial. Systolic blood pressure (SBP) and heart rate variability were analysed at baseline, 5 min after SA and 15 min after SA. Patients were assigned by baseline LF/HF. Group LF/HF < 2.5 (n= 52) was compared to group LF/HF > 2.5 (n= 48). Non‐parametric tests for statistical analysis.

Results:  Group LF/HF > 2.5 showed a significant decrease in LF/HF and LF as well as an increase in HF during SA (median, range): baseline LF/HF [4.0 (3.2/4.8)] decreased to 2.3 (1.3/3.4) at event 15 min after SA (P < 0.001). Baseline LF = 59(43/71)% decreased to 40 (27/55)% at event 15 min after SA (P < 0.05). Baseline HF = 15(13/22)% increased to 26(15/41)% at event 15 min after SA (P < 0.05). In contrast, group LF/HF < 2.5 demonstrated only moderate changes in LF/HF, LF and HF during SA. SBP decreased significantly in group LF/HF > 2.5 (median and range) lowest SBP group LF/HF > 2.5: 80 (50/127 mmHg vs. group LF/HF < 2.5: 109 (104/142) mmHg, P < 0.001. Decrease of SBP before and after SA was correlated with a decrease in LF/HF, LF, and HF, respectively: LF/HF – SBP: r= 0.30, r2= 0.09, P < 0.001; LF – SBP: r= 0.25, r2= 0.06, P < 0.05, HF, NS.

Conclusions:  Changes in heart rate variability parameters in the course of SA may reflect a decrease in sympathetic activity and relative increase in parasympathetic activity as a result of the block. In the course of SA, the more pronounced the changes in heart rate variability were the more distinct the hypotension.
Choice reaction time in patients with post‐operative cognitive dysfunction*
Authors: STEINMETZ J. , RASMUSSEN L. S. ,   THE ISPOCD GROUP
Published: August 2010

Background: Post‐operative cognitive dysfunction (POCD) is detected by administration of a neuropsychological test battery. Reaction time testing is at present not included as a standard test. Choice reaction time (CRT) data from the first International Study of Post‐operative Cognitive Dysfunction study were collected, but the association between POCD and reaction time has not been presented before. We hypothesized that CRT could be used as a screening tool for POCD.

Methods: Patients aged 60 years or older scheduled for major surgery with general anaesthesia were recruited from 13 centres in nine countries. CRT was measured 52 times using the four boxes test. Patients performed the test before surgery (n=1083), at 1 week (n=926) and at 3 months (n=852) post‐operatively. CRT for the individual patient was determined as the median time of correct responses. The usefulness of the CRT as a screening tool for POCD was determined by the receiver–operator characteristic (ROC) curve.

Results: Patients with POCD 1 week after surgery had a significantly longer reaction time compared with patients without POCD: 857 (221) vs. 762 (201) ms, respectively (P<0.0001). Also at 3 months, patients with POCD had a significantly longer CRT. ROC curves revealed that a reaction time of 813 ms was the most appropriate cut‐off at 1 week and 762 ms at 3 months but the positive predictive value for POCD was low: 34.4% and 14.7%, respectively.

Conclusions: Post‐operative cognitive dysfunction is associated with impaired performance in the CRT test but the test is a poor predictor of POCD.
Bispectral index monitoring: appreciated but does not affect drug dosing and hypnotic levels*
Authors: LINDHOLM M.‐L. , BRUDIN L. , SANDIN R. H.
Published: August 2010

Background: Bispectral index (BIS) has been associated with benefits from less‐deep anesthesia as well as preventing awareness, albeit not at the same time. We investigated how increasing experience from BIS in clinical practice affect the hypnotic level, drug consumption, as well as subjective opinions on this monitoring.

Methods: Eight certified registered nurse anesthetists (CRNAs) with previous experience from 88 (46–121) BIS monitored cases anesthetized 80 cases with concealed BIS, followed by 80 cases with available BIS. Additional education and training was followed by yet another 160 patients randomized to open or blindly recorded BIS. BIS levels, anesthetic gas consumption, fentanyl use, and subjective opinions on utility and reliability were investigated.

Results: After gaining initial experience from BIS monitoring, the fraction of time with BIS levels of 40–60 did not deteriorate in cases with concealed monitoring and no further improvement was found in subsequent cases with available data from the BIS monitoring, not even after additional training and encouragement to adhere to the 40–60 interval. Compared with the first experience from BIS monitoring the subjective opinions on utility had increased from 33 to 78 mm (100 mm visual analog scales) (P<0.0001).

Conclusion: Although BIS became considerably appreciated, growing experience and repeated education had no impact on drug dosing and BIS levels.
Clinical practice and routines for day surgery in Sweden: results from a nation‐wide survey
Authors: SEGERDAHL M. , WARRÉN‐STOMBERG M. , RAWAL N. , BRATTWALL M. , JAKOBSSON J.
Published: August 2010

Background: Day surgery has expanded considerably during the last decades. Routines and standards have developed but differ between and within countries.

Methods: We studied the practice of day surgery in Sweden by an extensive questionnaire survey sent to all 92 hospitals.

Results: The proportion of day surgery vs. in‐hospital procedures was overall 43%, with 43% in adults and 46% in children. Orthopaedic (33%), general (29%) and gynaecological (17%) surgery were the most common ambulatory procedures. Most patients (>90%) underwent pre‐operative assessment by an anaesthesiologist. Patient self‐assessment questionnaires were common (86%). Risk stratification for post‐operative nausea and vomiting was used by 70% of the departments. Anxiolytic pre‐medication was uncommon. Most anaesthesiologists (95%) used pre‐operative oral analgesics to initiate post‐operative analgesia, the most common being paracetamol (95%), NSAIDs (73%) and coxibs (15%). A balanced general anaesthesia technique was preferred. Post‐operatively, 93% of the units routinely assessed patients' pain. Analgesic combinations of paracetamol, NSAIDs and weak opioids were used by 94% of the units. Most hospitals (80%) had standardised discharge criteria based on clinical assessment, and many required a patient escort at home for 24 h post‐operatively. Assessments of unplanned admission, re‐admission and post‐operative complications were not performed routinely. Follow‐up telephone calls within 1–2 days were performed regularly in about 40% of the units, or in selected patients only (37%). Pain was the most frequent complaint on follow‐up.

Conclusions: In Sweden, a high degree of standardised regime for day surgical practice was found. Post‐operative pain is the most common complaint after discharge.
Exposure to noise during continuous positive airway pressure: influence of interfaces and delivery systems
Authors: CAVALIERE F. , CONTI G. , COSTA R. , SPINAZZOLA G. , PROIETTI R. , SCIUTO A. , MASIERI S.
Published: August 2010

Background: We measured noise intensity and perceived noisiness during continuous positive airway pressure (CPAP) performed with two interfaces (face‐mask, helmet) and four delivery systems.

Methods: Eight healthy volunteers received CPAP in random order with: two systems provided with a flow generator using the Venturi effect and a mechanical expiratory valve (A: Venturi, Starmed; B: Whisperflow‐2, Caradyne Ltd); one ‘free‐flow’ system provided with high flow O2 and air flowmeters, an inspiratory gas reservoir, and a water valve (C: CF800, Drägerwerk, AG); and a standard mechanical ventilator (Servoventilator 300, Siemens‐Elema). Systems A, B, and C were tested with a face‐mask and a helmet at a CPAP value of 10 cm H2O; the mechanical ventilator was only tested with the face mask. Noise intensity was measured with a sound‐level meter. After each test, participants scored noisiness on a visual analog scale (VAS).

Results: The noise levels measured ranged from 57±11 dBA (mechanical ventilator plus mask) to 93±1 and 94±2 dBA (systems A and B plus helmet) and were significantly affected by CPAP systems (A and B noisier than C and D) and interfaces (helmet CPAP noisier than mask CPAP). Subjective evaluation showed that systems A and B plus helmet were perceived as noisier than system C plus mask or helmet.

Conclusions: Maximum noise levels observed in this study may potentially cause patient discomfort. Less noisy CPAP systems (not using Venturi effect) and interfaces (facial mask better than helmet) should be preferred, particularly for long or nocturnal treatments.
Prevalence of self‐reported neuropathic pain and impact on quality of life: a prospective representative survey
Authors: GUSTORFF B. , DORNER T. , LIKAR R. , GRISOLD W. , LAWRENCE K. , SCHWARZ F. , RIEDER A.
Published: August 2010

Background: Data on the incidence of neuropathic pain (NeP) in Austria, its general characteristics and consequences for the quality of life (QOL) are still lacking. The prevalence in the United Kingdom is 8%.

Methods: A representative survey (n=7707) was carried out. Patients with NeP were identified using previously validated criteria and subsequently asked to complete a questionnaire on QOL and detailed pain characteristics.

Results: The prevalence of NeP was 3.3% (n=260). A higher prevalence was found in 41–50‐year‐olds (26%) and 51–60 year olds (24%). Pain was long lasting (>1 year: 66%; >5 years: 41%) and severe at onset (mean 6.8; numerical rating scale) as well as later (mean 4.7; 20% 8 or higher). Strong or predominant restriction of daily activities was reported in 65%, strong or predominant sleep disturbances in 60%, feelings of depression in 34% and anxiety in 25%.

Conclusion: For the first time, data on the prevalence of NeP in Austria are available. Pain patterns in those affected are characteristic and impact on QOL as well as pain intensity are severe.
Detection of carbon dioxide in expired air after oesophageal intubation; the role of bystander mouth‐to‐mouth ventilation
Authors: KRAMER‐JOHANSEN J. , DORPH E. , STEEN P. A.
Published: August 2010

Background: The identification of a correctly placed tube during anaesthesia routinely depends on the detection of carbon dioxide (CO2) in the expired air.

Results: We describe a previously unreported cause of false‐positive prediction in two patients with high initial values of CO2 in expired air after oesophageal intubation. Both patients had received bystander cardiopulmonary resuscitation with mouth‐to‐mouth ventilation, and the CO2 from the rescuers' expired air was trapped and subsequently detected after oesophageal intubation.
Tryptase levels after suxamethonium administration and defibrillation
Authors: STORJORD E. , NIELSEN E. W.
Published: August 2010

Background: A more than threefold increase in tryptase, when comparing with the control sample, strengthens the diagnosis of anaphylaxis. Trauma, coronary ischaemia and non‐IgE‐mediated reactions to several medications have been shown to cause more than threefold rise in tryptase levels. The aim of our study was to examine whether suxamethonium or defibrillation could lead to a more than threefold increase in tryptase in the absence of signs of anaphylaxis.

Methods: S‐tryptase was measured in 50 patients who had general anaesthesia with either pentothal and suxamethonium before electro convulsive therapy (ECT) to treat depression (n=31) or propofol before electro conversion to treat atrial fibrillation (n=19). Blood samples were collected minutes before and 1 h after the procedures.

Results: Tryptase values did not differ significantly before and after the procedures.

Conclusion: Tryptase levels do not increase in patients undergoing elective defibrillation or ECT with the administration of suxamethonium, in absence of symptoms of anaphylaxis.
Low dose of lidocaine: comparison of 15 with 20 mg/ml with dextrose for spinal anesthesia in lithotomy position and ambulatory surgery
Authors: IMBELLONI L. E. , GOUVEIA M. A. , CORDEIRO J. A.
Published: August 2010

Background: Spinal anesthesia with the local anesthetic lidocaine has come under scrutiny because it is associated with transient neurologic symptoms (TNS). Although TNS is not associated with either lidocaine concentration or dose, its incidence has never been examined with very small doses of hyperbaric spinal lidocaine in patients in the lithotomy position. We designed this study prospectively to compare the efficacy of low‐dose 15 mg/ml with low‐dose 20 mg/ml hyperbaric lidocaine in patients undergoing elective outpatient surgery in the lithotomy position.

Methods: A total of 100 patients were randomized to receive either 30 mg of 15 mg/ml or the same dose of 20 mg/ml hyperbaric lidocaine. Lidocaine density at 37 °C is 1.0241 g/ml for the 15 mg/ml and 1.0260 g/ml for the 20 mg/ml solution. Patients were examined for motor block, sensory block, and block duration. Patients were contacted at 24, 48 and 72 h and questioned about their perceptions of pain after the spinal anesthesia with specific questions designed to diagnose TNS.

Results: The spread of analgesia was the same with both solutions of lidocaine. Motor block was incomplete in all patients in both groups. TNS were not observed when low doses of both solutions of lidocaine with dextrose were used in these ambulatory patients in the lithotomy position.

Conclusion: Hyperbaric lidocaine results in rapid recovery from sensory block and motor blockade. It may have advantages for patients in a day‐case setting. No patients complained of TNS after discharge.
Pulse pressure variation and stroke volume variation during different loading conditions in a paediatric animal model
Authors: RENNER J. , CAVUS E. , MEYBOHM P. , GRUENEWALD M. , STEINFATH M. , SCHOLZ J. , BOENING A. , BEIN B.
Published: August 2010

Background: Previous studies in adult patients and animal models have demonstrated that pulse pressure variation (PPV) and stroke volume variation (SVV) can be used to predict the response to fluid administration. Currently, little information is available on the performance of these variables in infants and neonates. The aim of our study was to assess whether PPV and SVV can predict fluid responsiveness in an animal model and to investigate the influence of different tidal volumes applied.

Methods: PPV and SVV were monitored by pulse contour analysis in 19 anaesthetized and paralysed piglets during ventilation with tidal volumes (VT) of 5, 10 and 15 ml/kg both before and after fluid loading with 25 ml/kg of hydroxy‐ethyl starch 6% (HES). Cardiac output was measured by pulmonary artery thermodilution and a positive response to HES infusion was defined as ≥20% increase in the stroke volume index (SVI).

Results: Before HES infusion, PPV and SVV were significantly greater during ventilation with a VT of 10 and 15 ml/kg than during ventilation with a VT of 5 ml/kg (P<0.05). After HES infusion, only ventilation with VT 15 ml/kg resulted in a significant increase in PPV and SVV. As assessed by receiver operating characteristic curve analysis, SVV during ventilation with VT 10 ml/kg was the best predictor of a positive response to fluid loading (AUC=0.87).

Conclusions: In this paediatric animal model, we found that SVV during ventilation with 10 ml/kg was a sensitive and specific predictor of the response to fluid loading.
Usefulness of a central venous catheter during hepatic surgery
Authors: STÉPHAN F. , REZAIGUIA‐DELCLAUX S.
Published: August 2010

Aim: Central venous catheter (CVC) is often inserted during liver resection because a low central venous pressure (CVP) reduces blood loss and the procedure may be associated with circulatory impairment. The aim of the study was to evaluate the usefulness of a CVC besides the measurements of CVP, and whether peripheral venous pressure (PVP) measurement could be used reliably in place of CVP.

Methods: We conducted an observational study during a 16‐month period. Number of CVC inserted, expected surgical difficulties, and intraoperative complications which could lead to treatment involving a CVC were prospectively recorded and analysed. Measurements of CVP and PVP were simultaneously obtained at different times during surgery. Bias and limits of agreement with their 95% confidence interval (95% CI) were calculated.

Results: Of the 101 patients included, 28 had expected surgical difficulties. Of the 75 CVCs inserted, only six (8%) were used for another purpose that CVP measurement in patients with expected surgical difficulties. A total of 124 measurements in 23 patients were recorded. Mean CVP was 4.8 ± 2.9 mmHg and mean PVP was 6.9 ± 3.1 mmHg (P<0.0001). The bias was −2.1 ± 1.1 mmHg (95% CI: −2.3 to −1.9). When adjusted by the average bias of −2 mmHg, PVP predicted a CVP≤5 mmHg with a sensitivity and a specificity of 93% and 87%, respectively.

Conclusion: Routine insertion of a CVC should be discussed in patients without expected surgical difficulties. Thus, PVP monitoring may suffice to estimate CVP in uncomplicated cases.
Infusion of albumin attenuates changes in serum protein binding of drugs in surgical patients compared with volume replacement with HAES
Authors: REINE P. A. , KONGSGAARD U. E. , ANDERSEN A. , THØGERSEN A.‐K. , OLSEN H.
Published: August 2010

Background:In vitrostudies have indicated that stabilizers present in pharmaceutical‐grade albumin influence albumin‐binding capacity for highly protein bound drugs.

Methods:A randomized study including 40 surgical patients, treated with either albumin or starch solutions, was performed. Volumes of colloids were given based on clinical indication. Blood samples were obtained. The serum samples were analyzed to determine the concentrations of albumin, tryptophan,N‐acetyl‐dl‐tryptophan, caprylate and α‐1‐acid glycoprotein as well asin vitrodrug binding of naproxen, warfarin and digitoxin.

Results:During surgery, the albumin concentration declined in the Starch group from 26.8 to 15.3 g/l. It remained unchanged in the Albumin group (29.2 g/l). The two groups were analyzed with the pre‐operative sample acting as the control. In the starch group, the percent free concentration of the drugs increased significantly (P<0.01): for naproxen from 0.2% to 0.6%, for warfarin from 1.2% to 1.8% and for digitoxin from 6.8% to 11.1%. In the Albumin group, the % free fraction of naproxen doubled from 0.1% to 0.2% (P<0.05), whereas the % free fraction of warfarin decreased from 1.1% to 1.0% (P<0.05). The free fraction of digitoxin remained unchanged.

Conclusions:Infusion of albumin during surgery resulted in maintained albumin values and almost maintained binding parameters for the study drugs, although some statistically significant changes were found. The use of starch solutions, however, led to in a reduction in albumin values and a significant reduction in binding parameters.
Laparoscopic colon surgery: unreliability of end‐tidal CO2 monitoring
Authors: KLOPFENSTEIN C. E. , SCHIFFER E. , PASTOR C. M. , BEAUSSIER M. , FRANCIS K. , SORAVIA C. , HERRMANN F. R.
Published: August 2010

Background: The relatively good haemodynamic and respiratory tolerance to abdominal CO2 insufflation has mostly been observed in healthy patients during short‐lasting laparoscopic procedures. End‐tidal CO2 pressure (PetCO2) has been shown to be a reliable method to assess arterial CO2 (PaCO2) in the absence of cardio‐respiratory disease in this setting. However, no study has investigated whether PetCO2 is accurately related to PaCO2 during laparoscopic colon surgery. Indeed, these procedures last longer, prolonging the pneumoperitoneum and requiring a Trendelenburg position. The aim of the present study was to measure the PaCO2–PetCO2 difference over time in patients undergoing laparoscopic colon surgery and to determine whether PaCO2 is reliably assessed by PetCO2.

Methods: Forty consecutive patients (ASA I and II) scheduled for laparoscopic colon surgery were anaesthetized and ventilated to obtain a PetCO2 between 4.0 and 5.5 kPa. After initiation of CO2 insufflation, PaCO2 and PetCO2 were recorded every 30 min during surgery.

Results: No complication was observed during anaesthesia. The mean arterial pressure increased significantly after CO2 insufflation and remained steady up to the end of pneumoperitoneum. The heart rate remained stable over time. The relation between PaCO2 and PetCO2 was not constant among patients and increased over time within the same patients. The R2 values fluctuated and did not show a constant correlation between PaCO2 and PetCO2.

Conclusion: The correlation between PaCO2 and PetCO2 during laparoscopic colon surgery is inconsistent mainly due to inter‐ and intra‐individual variability.
Effects of pain stimulation on bispectral index, heart rate and blood pressure at different minimal alveolar concentration values of sevoflurane
Authors: SANDIN M. , THÖRN S.‐E. , DAHLQVIST A. , WATTWIL L. , AXELSSON K. , WATTWIL M.
Published: August 2010

Background: The aim of the present study was to examine the level of unconsciousness measured with bispectral index (BIS) at different minimal alveolar concentration (MAC) levels of sevoflurane, and to study the hemodynamic and BIS reactions during noxious stimulation with transcutaneous electrical nerve stimulation (TENS) and an ice water pain test (IWP).

Methods: This study was approved by the Ethics Committee and was performed on 10 healthy, young volunteers (six males and four females), ASA physical status I. Anesthesia was induced and maintained with sevoflurane in an oxygen/air mixture. The volunteers were spontaneously breathing, but if necessary, ventilation was mechanically supported. TENS and IWP were performed at 1.0, 1.5 and 2.0 MAC of sevoflurane.

Results: At 1.0 MAC, there was a significant increase in BIS during pain stimulation both with IWP (P<0.03) and with TENS (P<0.005), but at 1.5 MAC there were no changes. A marked variation in BIS was seen at 2.0 MAC, with periods of burst suppression and periods of high BIS values despite clinical signs of deep anesthesia. These marked variations in BIS were seen before, during and after pain stimulation. One volunteer (# 8) had a short episode of convulsions at 2.0 MAC.

Conclusion: BIS, heart rate and blood pressure increased during pain stimulation at 1.0 MAC but not at 1.5 MAC of sevoflurane. There was a remarkable variation in BIS at 2.0 MAC of sevoflurane, with BIS values indicating wakefulness despite clinical signs of deep anesthesia. This BIS variation is probably caused by epileptogenic activity due to sevoflurane.
Effects of the cannabinoid antagonist AM281 on systemic hemodynamics and mortality rate in streptozotocin‐induced diabetic rats with endotoxic shock: comparison between non‐diabetic and diabetic rats
Authors: KADOI Y. , HINOHARA H. , KUNIMOTO F. , SAITO S.
Published: August 2010

Purpose:On the basis of previous findings that the anandamide antagonist AM281, an endogenous cannabinoid receptor antagonist, could restore the hemodynamic and cerebral blood flow changes and improve the mortality rate in non‐diabetic rats during sepsis, this study was conducted to examine whether AM281 could restore the hemodynamic variables and improve the mortality rate in streptozotocin‐induced diabetic rats during sepsis.

Methods:The study was designed to include three sets of experiments, each set of experiment being conducted in both diabetic and non‐diabetic animals: (1) measurement of changes in systemic hemodynamics and carotid artery blood flow, (2) measurement of biochemical variables and (3) assessment of mortality rate. Systemic hemodynamics, carotid artery blood flow changes and biochemical variables were assessed at pre‐treatment and 1, 2 and 3 h after the treatment was performed.

Results:In both non‐diabetic and diabetic rats, administration of lipopolysaccharide (LPS) induced a reduction in hemodynamic variables, these reductions being greater in diabetic than in non‐diabetic rats. In diabetic rats, administration of AM281 could only partially prevent these hemodynamic changes, these changes being insufficient to elevate these variables to control values. Significant differences were observed in mortality rates at 6 and 12 h between non‐diabetic and diabetic groups with the same treatment. At 12 h, only non‐diabetic AM281 group rats were still alive (mortality rate 50%).

Conclusion:Administration of AM281 only partially prevented the hemodynamic, biochemical and carotid artery blood flow changes associated with LPS‐induced septicemia in diabetic rats, as compared with non‐diabetic rats in whom these changes were prevented to a greater extent.
Intrathecal low‐dose hyperbaric bupivacaine–clonidine combination in outpatient knee arthroscopy: a randomized controlled trial
Authors: VAN TUIJL I. , GIEZEMAN M. J. M. M. , BRAITHWAITE S. A. , HENNIS P. J. , KALKMAN C. J. , VAN KLEI W. A.
Published: August 2010

Background: Spinal anesthesia for knee arthroscopy can be produced with a low dose of bupivacaine, but additional intrathecal drugs are often required to lower the risk of failed blocks. We investigated the effect of the addition of clonidine (0, 15 or 30 μg) to 5 mg hyperbaric bupivacaine on the duration of the motor block, analgesic quality and ability to void after the surgery in a randomized controlled trial.

Methods: Seventy‐five patients received spinal anesthesia using either 5 mg hyperbaric bupivacaine (B5C0), 5 mg hyperbaric bupivacaine with 15 μg clonidine (B5C15) or 5 mg hyperbaric bupivacaine with 30 μg clonidine (B5C30). The primary outcome was the duration of the motor block. Secondary outcomes included the time until spontaneous voiding, and the need for additional analgesia or general anesthesia.

Results: The mean time to complete regression of motor block was 70 (±43) min in group B5C0. Adding 15 and 30 μg of clonidine increased the motor block duration by 25 [95% confidence interval (CI): 2–48] and 34 (95% CI: 11–57) min, respectively, but resulted in better analgesic quality. The mean time until spontaneous voiding was 177 min in the B5C0 group. This time increased with 18 (95% CI −13 to 49) and 44 (95% CI 15–74) min in group B5C15 and group B5C30, respectively.

Conclusion: The addition of 15 μg clonidine to 5 mg of intrathecal hyperbaric bupivacaine prolongs the duration of motor block and improves the quality of the block.
Fluoroscopic guidance of Arndt endobronchial blocker placement for single‐lung ventilation in small children
Authors: MARCINIAK B. , FAYOUX P. , HÉBRARD A. , ENGELHARDT T. , WEINACHTER C. , HORBER R. K.
Published: August 2010

Background: Thoracoscopic surgery may require single‐lung ventilation (SLV) in infants and small children. A variety of balloon‐tipped endobronchial blockers exist but the placement is technically challenging if the size of the tracheal tube does not allow the simultaneous passage of the fibreoptic scope and the endobronchial blocker. This report describes a technique for endobronchial blocker insertion using fluoroscopic guidance in children undergoing SLV.

Methods: After approval from the local Medical Ethics Committee and parental consent, 18 patients aged 2 years or younger scheduled for thoracic surgery requiring SLV were prospectively included. Following induction of anesthesia, a 5 Fr endobronchial blocker (Cook® Arndt endobronchial blocker) was inserted first into the trachea under direct laryngoscopy. Correct placement in the main bronchus was assessed by fluoroscopy and tracheal intubation next to the endobronchial blocker. Optimal position and balloon inflation was verified using a fibreoptic scope. The duration and number of insertion attempts as well as age, weight and size of the tracheal tube were recorded.

Results: Eighteen patients were studied. Median (range) age and weight were 12 (0.2–24) months and 11.2 (4–15) kg, respectively. SLV was successfully achieved in all patients using a 5 Fr endobronchial blocker outside a 3.5–4.5 mm ID tracheal tube within 11.2 (±2.2) min. No side effects were observed during the procedure.

Conclusion: Fluoroscopic‐guided insertion of extraluminal endobronchial blocker is an effective and reliable tool to place Arndt endobronchial blockers in small children.
Isoflurane attenuates myoglobin release during ischemic and/or reperfusion periods
Authors: KITAGAWA H. , YAMAZAKI T. , AKIYAMA T. , NOSAKA S. , MORI H.
Published: August 2010

Background: Recently, we have developed cardiac microdialysis for detection of protein leakage from the injured myocardium. We examined whether the exposures to isoflurane would exert a beneficial effect on myocardial injury caused by ischemia or reperfusion.

Methods: A dialysis probe was implanted into the left ventricle free wall in the rabbits. The dialysate myoglobin level served as an index of myocardial interstitial myoglobin levels. Rabbits were randomly assigned to one of three groups: (1) without exposure to isoflurane (vehicle, n=6), (2) inhale 1 MAC isoflurane once for 30 min (ISO30‐1, n=6), and (3) twice for 30 min (ISO30‐2, n=6). All rabbits underwent 30 min of coronary occlusion and 60 min of reperfusion. To determine whether the isoflurane induced myocardial protection against chemical hypoxia, sodium cyanide (30 mM) was administered and dialysate myoglobin levels were measured with (n=6) and without pre‐exposure to isoflurane twice for 30 min (n=6).

Results: In all three groups dialysate myoglobin levels were increased by coronary occlusion and furthermore augmented by reperfusion. In comparison with the vehicle group, the ISO30‐1 group suppressed only the increase in the dialysate myoglobin level during reperfusion. The ISO30‐2 group suppressed during both the ischemic and reperfusion periods. Cyanide induced increases in dialysate myoglobin levels. These increments in dialysate myoglobin levels were suppressed by repeated exposure to isoflurane.

Conclusion: Repeated exposure to isoflurane suppressed myocardial myoglobin release caused by both ischemia and reperfusion injury. Isoflurane may provide protection against myocardial ischemia/reperfusion and hypoxic injuries.
Insulin alters cytokine content in two pivotal organs after brain death: a porcine model
Authors: BARKLIN A. , LARSSON A. , VESTERGAARD C. , KJAERGAARD A. , WOGENSEN L. , SCHMITZ O. , TØNNESEN E.
Published: August 2010

Background:To optimize the quantity and quality of organs available for transplantation, it is crucial to gain further insight into the treatment of brain dead organ donors. In the current study we hypothesized that insulin treatment after brain death alters cytokine content in the heart, liver, and kidney.

Methods:Sixteen brain dead pigs (35–40 kg) were treated with either (1) no insulin [brain dead without insulin treatment treatment (BD)], or (2) insulin infusion intravenously (i.v.) at a constant rate of 0.6 mU/kg/min during 360 min [brain dead with insulin treatment (BD+I)]. Blood glucose was clamped at 4.5 mmol/l by infusion of 20% glucose. Blood samples for insulin, glucose, catecholamines, free fatty acids, and glucagon were obtained during the experimental period. Six hours after brain death biopsies were taken from the heart, liver, and kidney. These were analyzed for cytokine mRNA and proteins [tumor necrosis factor‐α (TNF‐α), interleukin (IL)‐6, and IL‐10].

Results:The BD+I compared with the BD animals had lower IL‐6 concentrations in the right ventricle of the heart (P=0.001), in the renal cortex (P=0.04) and in the renal medulla (P=0.05), and lower IL‐6 mRNA in the renal medulla (P=0.0002). Furthermore, the BD+I animals had lower concentrations in the renal medulla of IL‐10 (P=0.01), and tended to have lower TNF‐α in the renal cortex (P=0.06) than the BD animals. In the right ventricle of the heart TNF‐α mRNA and IL‐10 mRNA were higher in the BD+I than in the BD group (P=0.002 and 0.004).

Conclusion:Insulin has anti‐inflammatory effects on cytokine concentration in the heart and kidney after brain death.
A controlled comparison between single doses of intravenous and intramuscular morphine with respect to analgesic effects and patient safety
Authors: TVEITA T. , THONER J. , KLEPSTAD P. , DALE O. , JYSTAD Å. , BORCHGREVINK P. C.
Published: August 2010

Background and aim of investigation:Intramuscular (IM) administration has been considered to be safer than intravenous (IV) for opioids on wards, but a comparative knowledge of patient safety and analgesic potency following a single dose of IV and IM administration is lacking. This study was carried out to compare patient safety and analgesic efficacy of a single and high dose of morphine given IM or IV for post‐operative pain management.

Materials and methods:Thirty‐eight patients with post‐operative pain following hip replacement surgery were given IM or IV morphine 10 mg at a specified pain level. The study was randomized and double blinded. Time to onset of analgesic effect (11‐point numeric rating scale), respiratory function (paCO2, paO2, and respiratory rate), level of sedation (5‐point verbal rating scale), and hemodynamic function were recorded.

Results:In the IV group there was a slight but significant increase in paCO2after 5, 10, and 15 min compared with the IM group (5.2 vs. 4.8, 5.4, vs. 5.0 and 5.5 vs. 5.1 kPa, respectively). The IV group had a significantly faster onset of analgesic effect than the IM group (5 vs. 20 min). Between 5 and 25 min after morphine administration, pain status in the IV group was significantly improved compared with the IM group. Patients in the IV group were slightly more sedated than the IM group 5 and 10 min after morphine.

Conclusion:A 10 mg bolus dose of IV morphine given to patients with moderate pain after surgery does not cause severe respiratory depression, but provides more rapid and better initial analgesia than 10 mg given IM. IV morphine even at a dose as high as 10 mg IV is well tolerated if there is a certain level of pain at its administration. The safety of IV morphine on the general ward needs to be further explored in adequately controlled studies.