bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maintained cardiac output during positive end‐expiratory pressure ventilation in open‐chest pigs
Authors: BERGLUND J. E. , HALDÉN E. , JAKOBSON S. 
Published: January 2009

Background:Does ventilation with positive end‐expiratory pressure (PEEP) act to reduce cardiac output (CO) not only by impeding venous return but also by inducing myocardial depression? The present study was aimed to demonstrate the possible existence of this latter mechanism.Methods:Eight pigs of Swedish native breed weighing 20–25 kg and 10–12 weeks old were anaesthetized, tracheotomized and connected to a volume‐controlled ventilator. To prevent intra‐thoracic pressure from interfering with venous return, the heart and juxtacardiac vessels were exposed to atmospheric pressure by opening and retracting the chest and pericardium. Heart rate (HR), CO, stroke volume (SV), mean arterial (MAP), mean right (MRAP) and left (MLAP) atrial pressures were recorded before and after retransfusion of 500 ml of autologous blood. This procedure was carried out twice in each animal ‐ during ventilation with zero and with 15 cm H2O of PEEP.Results:Comparison of the two ventilation modes before volume load revealed negligible differences in HR, CO, SV, MAP, MRAP and MLAP. Moreover, the changes evoked by volume load were practically identical.Conclusions:Addition of PEEP to regular positive pressure ventilation does not induce any haemodynamically detectable myocardial depression in the piglet.
A survey of the ASA physical status classification: significant variation in allocation among Finnish anaesthesiologists
Authors: RANTA S. , HYNYNEN M. , TAMMISTO T. 
Published: January 2009

Background:The American Society of Anesthesiologists' (ASA) Classification of Physical Health is a widely used grading system for preoperative health of the surgical patient. In previous studies conducted in North America and Great Britain, considerable variation in the ASA classification allocation has been reported. We hypothesised that in smaller and culturally more homogeneous countries there might be less variation in the ASA classification.Methods: A postal questionnaire depicting 10 hypothetical patient cases was sent to 249 randomly selected members of the Finnish Society of Anaesthesiologists. Responses of anaesthesiologists working in university teaching and non‐teaching hospitals were compared, as well as the answers of specialists and non‐specialists.Results: Responses were received from 108 anaesthesiologists (response rate 43%). There was marked variation in the classification of all the 10 cases: 1 case was classified to all five possible grades (ASA grades I‐V). In 2 cases, there was significant variation between anaesthesiologists working in university teaching and non‐teaching hospitals. There was no difference in the grading between specialist and non‐specialist anaesthesiologists.Conclusion:In a small and culturally homogeneous country, like Finland, there exists similar wide variation in the ASA classification as has been previously reported from larger and culturally more heterogeneous countries. The significant variation should always be considered when using this classification in clinical or scientific work.
Large increase in cardiac output in a patient with ARDS and acute right heart failure during inhalation of nitric oxide
Authors: BENZING A. , MOLS G. , BEYER U. , GEIGER K. 
Published: January 2009

Background Inhaled nitric oxide (NO), a selective pulmonary vasodilator, reduces pulmonary artery pressure in patients with acute respiratory distress syndrome (ARDS). In spite of the reduction of right ventricular afterload, the effect of NO on cardiac output remains unclear.Methods:A patient with ARDS and echocardiographically determined severe acute right heart failure was treated with increasing concentrations of inhaled nitric oxide (NO). Haemo‐dynamic and gas exchange variables were determined for each concentration of NO. NO treatment was continued for 3 days.Results:During initial right heart failure, administration of NO: resulted in a large increase (32%) in cardiac output in a dose‐dependent manner. When right ventricular function had improved, inhalation of NO did not increase cardiac output.Conclusion: Our observations suggest that inhalation of NO is likely to increase cardiac output in ARE when severe acute right heart failure is present.
The combination of external high‐frequency oscillation and pressure support ventilation in acute respiratory failure
Authors: TAKEDA S. , NAKANISHI K. , TAKANO T. , NEJIMA J. , TAKAYAMA M. , OGAWA R. 
Published: January 2009

Background: Effective gas exchange can be maintained in animals by using external high‐frequency oscillation (EHFO). The present study evaluates the effect of relatively long‐term duration EHFO combined with pressure support ventilation (PSV) in patients with acute respiratory failure.Methods: Twelve patients were ventilated with EHFO combined with PSV for 8 h at 60 oscillations min‐1, with a cuirass pressure of 36 cm H2O: ‐26 to +10 cm H2O (27 mm Hg: ‐19.5 to +7.5 mm Hg) and an inspiratory‐to‐expiratory ratio of 1: 1. Blood gas values and hemodynamic parameters were measured. Results: Significant increases were noted in cardiac index (3.0±0.7 to 3.2±0.7 1 min‐1 m‐2, P < 0.05) and stroke volume index (32±14 to 35±13 ml m‐2, P < 0.05) without changes in pulmonary artery wedge pressure at 1 h after EHFO. PaO2(kPa)/FiO2 and PaCO2 improved from 21.9±7.5 to 26.8±8.0 (P < 0.05) at 2 h and from 6.9±1.7 to 6.1±0.9 kPa (P < 0.01) at 30 min after EHFO, respectively. Breath sounds could be heard well throughout the lung fields after institution of EHFO. The mucous rales also decreased.Conclusions: As a method of ventilation for patients with acute respiratory failure, EHFO combined with PSV may have potential advantages over conventional mechanical ventilation when drainage of secretions is facilitated. Beneficial effects of EHFO may appear after several hours.
Atrial natriuretic peptide and N‐terminal atrial natriuretic peptide in plasma reflect right ventricular volumes following coronary artery surgery
Authors: HONKONEN E. L. , KAUKINEN L. , PEHKONEN E. J. , KAUKINEN S. 
Published: January 2009

Background: Atrial natriuretic peptide (ANP) and the more stable N‐terminal fragment (N‐ANP) of prohormone are peptides, released in equimolar amounts from cardiac myocytes in response to atrial stretch or ventricular overload and myocardial ischaemia. Protection of the right ventricular (RV) myocardium during ischaemia in cardiac surgery is difficult, especially in patients with severe right coronary artery (RCA) disease. This prospective study was designed to ascertain a possible relationship between changes in plasma ANP/N‐ANP concentration and RV function in RCA‐diseased patients.Methods: Plasma ANP and N‐ANP concentrations and RV function, measured by fast‐response thermodilution, were determined serially in 15 patients with total RCA stenosis and in another 15 with no significant RCA disease (controls) before, during and after coronary artery surgery.Results:The RV ejection fraction was lower and the RV end‐systolic volume index higher in the RCA‐diseased patients than in the controls (P < 0.05) on the second postoperative day, and both ANP and N‐ANP were higher in the RCA patients (P < 0.05) from 6 h after cardiopulmonary bypass till the second postoperative day. At the same time the changes in N‐ANP concentrations from the levels before induction of anaesthesia correlated with RV ejection fraction and RV volume indexes, but not with heart rate or parameters indirectly reflecting left‐sided loading. Right atrial pressure did not differ between the groups nor did it increase significantly during the study.Conclusions:The relationships found between N‐ANP and RV volume indexes and RV ejection fraction suggest ventricular expression of ANP: ANP release may be stimulated by RV distension, the more so the poorer the RV function.
Mivazerol, a new α2‐adrenergic agonist, blunts cardiovascular effects following surgical stress in pentobarbital‐anesthetized rats
Authors: ZHANG X. , WÜLFERT E. , HANIN I. 
Published: January 2009

Background:Mivazerol is a new and selective α2‐adrenoceptor agonist, devoid of hypotensive effects, which has been designed to prevent adverse cardiac outcome in perioperative patients with, or at risk of coronary artery disease.Methods:In the present study, the effects of mivazerol on hemodynamic changes induced by trachea‐exposure surgery stress were investigated in pentobarbital‐anesthetized rats, and compared to those of dexmedetomidine.Results:Intravenous infusion of 3 different doses of mivazerol (3.75, 7.5 and 15 μg kg‐1 h‐1) did not significantly alter BP but caused a dose‐related decrease in HR. The maximal decrease in HR was approximately 87 beats/min. Contrary to mivazerol, dexmedetomidine (7.5 μg kg‐1 h‐1, i.v.) decreased both BP (11±3.2 mmHg) and HR. The maximum decrease in HR was approximately 104 beats/min. Surgical stress produced a rapid increase in BP (maximal increase of 50 mmHg) and HR (maximal increase of 100 beats/min), which lasted for at least 15 min. Constant infusion of mivazerol, at a dose of 15 μg kg‐1 h‐1, beginning 20 min prior to surgery and lasting for 35 min, significantly inhibited surgical stress‐induced increases in BP (P < 0.05) and HR (P < 0.001). Dexmedetomidine, at a dose which produced hypotension and profound bradycardia prior to surgery, did not have any effect on the surgical stress‐induced elevation in BP (P>0.05), but prevented the increase in HR (P < 0.05). Pretreatment with the α2‐adrenoceptor antagonist rau‐wolscine (0.5 mg/kg, i.v.) blocked the bradycardia induced by mivazerol as well as the inhibitory effect of mivazerol on surgical stress‐induced elevations in HR and BP.Conclusion:Mivazerol attenuates surgical stress‐induced elevations in BP and HR during pentobarbital anesthesia in rats, and these effects are mediated by stimulation of α2‐adrenoceptors. Unlike dexmedetomidine, mivazerol does not reduce BP, and is also more potent than dexmedetomidine in blunting surgical stress‐induced increases in BP in pentobarbital‐anesthetized rats.
Impedance cardiography in cardiac surgery patients: abnormal body weight gives unreliable cardiac output measurements
Authors: VAN DER MEER B. J. M. , VRIES J. P. P. M DE , SCHREUDER W. O. , BULDER E. R. , EYSMAN L. , VRIES P. M. J. M. DE 
Published: January 2009

Background: To study the accuracy of cardiac output measurement by means of Electrical Impedance Cardiography (EIC) in post‐cardiac surgery patients.Methods: In a prospective study, we compared cardiac output measurements by means of thermodilution (COTD) with impedance cardiographic‐derived values (COEIC) in 37 mechanically ventilated patients after cardiac surgery. Both methods were used simultaneously.Results: COEIC values were weakly correlated with COTD in the total group when the equation of Sramek‐Bernstein was employed to calculate COEIC (r=0.60, P < 0.001, mean difference and standard deviation: ‐0.06±1.25 l‐min‐1). After exclusion of the 12 patients whose body weight differed >15% from their ideal body weight, no significant difference was found between the mean values (5.40±1.80 l‐min‐1 (COEIC) vs 5.31±1.69 l‐min‐1, n=25) while the correlation coefficient increased substantially (r=0.85, P < 0.001, mean difference and standard deviation: 0.09±0.96 l‐min‐1).Conclusions: The results of this study indicate that weight is a very important factor in unreliable measurement of CO by impedance cardiography in cardiac surgery patients. The calculation equation as proposed by Sramek and Bernstein is not accurate enough in patients with more than 15% of weight deviation. Therefore, the use of impedance cardiography in these patients is of limited value until an accurate correction factor has been developed.
Complement partially mediates acid aspiration‐induced remote organ injury in the rat
Authors: YAMADA H. , KUDOH I. , NISHIZAWA H. , KANEKO K. , MIYAZAKI H. , OHARA M. , OKUMURA F. 
Published: January 2009

Background:Acid aspiration into one lung is known to cause both a local as well as remote organ injury characterized by neutrophil sequestration and subsequent edema. This study investigated the role of the complement cascade in the development of acid aspiration‐induced local lung and remote organ injuries using K‐76 COONa (K76), an anticomplement agent that inhibits the complement pathway at the C5 step, and its usefulness as a treatment drug.Methods: Anesthetized rats underwent tracheostomy and insertion of a cannula. K76 was intraperitoneally administrated prior to or immediately after the instillation of 0.1 ml of HC1 (0.1N) or phosphate buffer solution (PBS) into the left lung. Inflammatory responses were evaluated by tumor necrosis factor a (TNFa) in the plasma and the bronchoalveolar lavage fluid (BALF) (n=4), tissue myeloperoxidase (MPO), wet‐to‐dry weight ratio (W/D ratio)(n=6), and protein concentration in the BALF (n=6).Results: Acid instillation caused an increase in the plasma TNFa, which was significantly attenuated by the administration of K76 prior to or after the acid instillation. Acid instillation to the left lung resulted in an increase of MPO and W/D ratios of the left lung, the right lung, and the small intestine. The administration of K76 inhibited the increase of MPO in these organs. K76 inhibited the increase of W/D ratios of the right non‐in‐stillated lung and the small intestine. Acid instillation led to increased protein concentration in the BALF of the left lung, which was not inhibited by K76. K76 administrated after the acid instillation had the same effects. TNFa in the BALF was not detected in all groups.Conclusion:These results suggest that localized acid aspiration induces, through the C5a step of the complement system‐dependent mechanisms, TNFa formation and neutrophil sequestration, which caused the increase of endothelial permeability of the systemic organs. K76 is effective as a treatment drug in modulating some of the injuries caused by the acid instillation, but further investigation is warranted as to its potential as a therapeutic agent.
Central cardiovascular and oxygen variables during haemorrhage in the pig
Authors: KRANTZ T. , SZTUK F. , SWIATEK F. , JACOBSEN J. , SECHER N. H. 
Published: January 2009

Background:We evaluated the ability of the standards issued by the Danish Society of Anaesthesiologists to reflect a blood loss.Methods:In 9 pigs bled (0–24 ml kg‐1) and retransfused (to 28 ml kg‐1) during halothane anaesthesia, central cardiovascular, thoracic electrical impedance (TI), oxygen, acid‐base and temperature variables were recorded.Results: With the recommendation for minor surgery (mean arterial pressure (MAP) and heart rate (HR)), the correlation to the blood loss was 0.74 (P < 0.001) and with that for major surgery (MAP, HR, central venous pressure (CVP) and rectal temperature (Tempr)) it was 0.79 (P < 0.001). With the recommendation for extensive surgery (MAP, HR, CVP, pulmonary artery catheter variables and the central‐peripheral temperature difference (ΔTempr‐t)), the correlation was 0.84 (P < 0.001). Non‐invasive monitoring (MAP, HR, ΔTempr‐t TI and near‐infrared spectroscopy of the brain (SinvosO2)) was only slightly better than basal monitoring (r=0.76, P < 0.001). However, adding arterial base excess (BE), TI and peripheral temperature (Tempt) to the recommendation for major surgery resulted in a correlation of 0.87 (P < 0.001), while adding BE and TI to the recommendation for extensive surgery raised correlation to only 0.88 (P < 0.001).Conclusion:When the recommendations were followed the correlation to the blood loss ranged from 0.74–0.84. However, with the recording of MAP, HR, CVP, ΔTempr‐t, BE and TI a correlation of 0.87 was achieved, indicating that a pulmonary artery catheter may not be in need for patients undergoing surgical procedures with expected haemorrhage.
Serum soluble selectins in patients undergoing cardiopulmonary bypass. Relationship with circulating blood cells and inflammation‐related cytokines
Authors: DIAGO M. C. , GARCÍA‐UNZUETA M. T. , MARCANO G. , MERINO J. , SALAS E. , AMADO J. A. 
Published: January 2009

Background:Membrane‐bound selectins mediate the adhesion among leukocytes, platelets and endothelial cells, while circulating (soluble) selectins may function as competitive inhibitors of them. Open heart surgery is known to induce activation of these cells.Methods: We studied the acute responses of soluble selectins, circulating blood cells and inflammation‐related cytokines in 12 patients undergoing elective open heart surgery with cardiopulmonary bypass. Serial blood samples were withdrawn before, during and after surgery.Results: Serum soluble E‐selectin concentrations did not change significantly during all the perioperative period. In contrast, P‐selectin decreased after the initiation of cardiopulmonary bypass and remained low until the end of surgery. L‐selectin showed a similar course. A decrease in platelet count and albumin was found during the perioperative period and an increase in leukocyte count was found after cardiopulmonary bypass. Clear elevations in circulating IL (Interleukin)‐6, IL‐8, and IL‐10 were found after the end of surgery, while IL‐12 levels remained undetectable.Conclusions: While serum inflammatory cytokines clearly rise in response to open heart surgery, soluble selectins do not change (E) or decrease (P and L). Correcting for haemodilution, E‐selectin rises postoperatively, but the decrease in P‐ and L‐selectins is not explained by haemodilution.
Comparison of body temperature changes during laparoscopic and open cholecystectomy
Authors: MÄKINEN M.‐T. 
Published: January 2009

Background: Prevention of hypothermia during abdominal surgery by insulating or heat‐transferring methods has been the subject of numerous investigations. This study approaches the problem from a less discussed point of view, i.e. the effect of different surgical techniques on body temperature changes.Methods: Body temperature was measured at 3 core and 6 skin points in 40 patients scheduled for cholecystectomy through open laparotomy or laparoscopy with pneumoperitoneum created and maintained with unwarmed carbon dioxide (CO2) insufflation. End‐tidal CO2 was kept constant by adjustments of respiratory frequency. Anaesthesia, intravenous infusions, and draping of the patients were standardized.Results: During the first 1 h of anaesthesia core temperatures decreased approximately by 0.7˚C and distal skin temperatures increased by 7˚C in both groups. At the end of surgery heat balance was similar in both groups. An increase of 2.5 1 min‐1 in respiratory minute volume was needed to control end‐tidal CO2 levels in the laparoscopy group during pneumoperitoneum, which was maintained with a CO2 flow of 1.2 l‐min‐1 through the abdominal cavity.Conclusion:Laparoscopic technique with unwarmed carbon dioxide insufflation does not offer any advantage in terms of body temperature changes when compared to open surgery.
Granisetron reduces incidence of nausea and vomiting after breast surgery
Authors: FUJII Y. , TANAKA H. , TOYOOKA H. 
Published: January 2009

Background: Postoperative nausea and vomiting (PONV) remains a troublesome problem. This study was performed to evaluate the antiemetic efficacy of prophylactic granisetron, a selective 5‐hydroxytryptamine type 3 receptor antagonist, on the incidence of PONV in patients undergoing general anaesthesia for breast surgery.Methods: In a randomized, placebo‐controlled, double‐blind study, 50 female patients, 45–68 years, were given a single dose of either placebo (saline, n=25) or granisetron (40 ug kg‐1, n= 25) intravenously over 2–5 min immediately before the induction of anaesthesia. Postoperatively, during the first 24 hours after anaesthesia, the incidence of PONV and adverse events was recorded.Results: The treatment groups were similar for patient demographics, types of surgery, anaesthetic and postoperative management. Postoperatively, the incidence of PONV was 48% and 16% after administration of placebo and granisetron, respectively (P < 0.05). No differences in the incidence of other adverse events were observed between the two groups.Conclusion: Granisetron is an effective antiemetic for preventing PONV in patients undergoing general anaesthesia for breast surgery.
Serum potassium concentrations after suxamethonium in patients with familial amyloid polyneuropathy type I
Authors: VIANA J. S. , NEVES S. , VIEIRA H. , BENTO C. , PERDIGOTO R. , FURTADO A. L. 
Published: January 2009

Background:Suxamethonium produces an abnormal increase in serum potassium in some neurological diseases and some authors have suggested that it is safer not to use this drug in patients with familial amyloid polyneuropathy (FAP). However, there are no data previously reported to support this hypothesis. The aim of this study was to evaluate the magnitude of the potassium increase produced by suxamethonium in FAP type I.Method: Twenty‐one FAP Met 30 patients anaesthetised for liver transplantation were studied. Age was 34.9±6.9 years (mean± SD), time elapsed from first symptom 5.5 ±3.2 years and weight was 14±9% below ideal body weight. Anaesthesia was induced with thiopentone and low‐dose fentanyl. Samples for blood gas and electrolytes analyses were drawn before induction and 1 and 5 min after 1 mg/kg of suxamethonium was given for tracheal intubation.Results: Before induction serum potassium levels were 3.8±0.4 mmol/L. One minute after suxamethonium, values were 3.8±0.4 mmol/L and 5 min after 4.3±0.5 mmol/L. The maximal increase observed was 1.6 mmol/L (from 3.4 mmol/L to 5.0 mmol/L).Conclusion:The average increase in plasma potassium concentrations observed in FAP patients after suxamethonium was similar to the increase observed in a normal population by others. Our study can exclude the hypothesis that an anomalous increase in potassium would be a typical and frequent response to suxamethonium in FAP Met 30 patients. However, we cannot exclude that a dangerous rise in serum potassium may exist in a certain percentage of FAP patients.
The effect of halothane on mivacurium infusion requirements in adult surgical patients
Authors: KANSANAHO M. , OLKKOLA K. T. 
Published: January 2009

Background: The extent of interaction between volatile anaesthetics and neuromuscular blocking agents depends both on the inhalational anaesthetic and the muscle relaxant. Halothane has the weakest potentiating effect on neuromuscular blocking drugs and previous studies of the interaction between halothane and mivacurium have been contradictory. We were interested in determining the effect of different levels of halothane‐nitrous oxide anaesthesia on infusion requirements of mivacurium.Methods: Sixty adult surgical patients were studied. Anaesthesia was induced with thiopentone and fentanyl and intubation facilitated with mivacurium 0.15 mg kg‐1. The patients were randomly assigned to one of four study groups. The control group received nitrous oxide in oxygen (2: 1) supplemented with fentanyl, while in the other groups halothane was administered at different end‐tidal concentrations: 0.19% (Group 2), 0.37% (Group 3), 0.74% (Group 4), corresponding to 0.25, 0.5 and 1.0 MAC of halothane. Neuromuscular block was kept at 95% with a closed‐loop feedback infusion of mivacurium and monitored with electromyography. Plasma cholinesterase concentrations and dibucaine numbers were determined.Results:Mivacurium infusion requirements (mean±SD) were 7.5±3.1 μg kg‐1 min‐1 with nitrous oxide‐fentanyl anaesthesia. In the groups receiving 0.25, 0.5 or 1.0 MAC of halothane the steady‐state infusion rates of mivacurium were reduced to 6.3±2.8, 5.6±1.4 and 5.7±2.5 μg‐kg‐1min‐1 (P < 0.05), respectively. There was a linear relationship between mivacurium infusion requirements and plasma cholinesterase activity.Conclusion: Halothane anaesthesia reduces mivacurium infusion requirements by 15–25% compared to nitrous oxide‐fentanyl anaesthesia. Interindividual differences in the extent of this interaction are great.