The effect of post-reperfusion levosimendan in an experimental intestinal ischemia-reperfusion model.

BACKGROUND: Levosimendan has been reported to have a positive effect on ischemia-reperfusion injury. Herein, we aimed to evaluate the effects of levosimendan applied after reperfusion in an experimental intestinal injury-reperfusion (IR) model. METHODS: Twenty-one Wistar-albino male rats were separated into three groups: Sham group (n = 7): solely superior mesenteric artery (SMA) was dissected after laparotomy; intestinal ischemia-reperfusion group (IIR, n = 7): SMA was clamped for 60 min and unclamped for 120 min to cause ischemia-reperfusion; IIR + levosimendan group (IIR + L, n = 7): levosimendan was administered in ischemia-reperfusion model. The mean arterial pressures (MAP) were measured in all groups. MAP measurements were performed at the end of stabilization, at the 15th, 30th, and 60th minute of ischemia; at the 15th, 30th, 60th, and 120th minute of reperfusion; and at the end of levosimendan bolus application and when levosimendan infusion concluded. Reperfusion injury was evaluated with tissue malondialdehyde (MDA) and by Chiu score. RESULTS: MAP at 15 min, 30 min, and 60 min of reperfusion was lower in IIR and IIR + L groups compared with basal inter-group measurements. Decline in MAP at 30 min after reperfusion was statistically significant in IIR and IIR + L groups when compared with the sham group. There was no significant difference between MDA levels in the groups. Chiu score was significantly lower in the sham group when compared to IIR and IIR + L groups and higher in IIR when compared to the IIR + L group. CONCLUSION: Levosimendan leads to a decrease in intestinal damage although it did not affect lipid peroxidation and MAP when administered after reperfusion in an experimental intestinal IR model.

Mortality Related Risk Factors in High-Risk Pulmonary Embolism in the ICU.

Introduction. We sought to identify possible risk factors associated with mortality in patients with high-risk pulmonary embolism (PE) after intensive care unit (ICU) admission. Patients and Methods. PE patients, diagnosed with computer tomography pulmonary angiography, were included from two ICUs and were categorized into groups: group 1 high-risk patients and group 2 intermediate/low-risk patients. Results. Fifty-six patients were included. Of them, 41 (73.2%) were group 1 and 15 (26.7%) were group 2. When compared to group 2, need for vasopressor therapy (0 vs 68.3%; p < 0.001) and need for invasive mechanical ventilation (6.7 vs 36.6%; p = 0.043) were more frequent in group 1. The treatment of choice for group 1 was thrombolytic therapy in 29 (70.7%) and anticoagulation in 12 (29.3%) patients. ICU mortality for group 1 was 31.7% (n = 13). In multivariate logistic regression analysis, APACHE II score >18 (OR 42.47 95% CI 1.50-1201.1), invasive mechanical ventilation (OR 30.10 95% CI 1.96-463.31), and thrombolytic therapy (OR 0.03 95% CI 0.01-0.98) were found as independent predictors of mortality. Conclusion. In high-risk PE, admission APACHE II score and need for invasive mechanical ventilation may predict death in ICU. Thrombolytic therapy seems to be beneficial in these patients.

Comparison of Two Different Enteral Nutrition Protocol in Critically Ill Patients.

OBJECTIVE: In this study, two enteral nutrition protocols with different gastric residual volumes (GRVs) and different monitoring intervals were compared with respect to gastrointestinal intolerance findings in intensive care unit (ICU) patients. METHODS: The study was carried out prospectively in 60 patients in the anaesthesiology and reanimation ICU under mechanical ventilation support, who were scheduled to take enteral feeding. Patients were sequentially divided into two groups: Group 1, GRV threshold of 100 mL, and monitoring interval of 4 hours, and Group 2, GRV threshold of 200 mL, monitoring interval of 8 hours. To test the significant difference between the groups, Student's t test, chi-square text and Fisher exact test were used. RESULTS: In Group 1, 3.3% vomiting, 6.6% diarrhoea was observed; in Group 2, 16.6% vomiting, 10% diarrhoea. In terms of total intolerance (vomiting and/or diarrhoea) of the two groups, the incidence was significantly higher in Group 2 (33.3%) than in Group 1 (10%) (p=0.02). CONCLUSION: According to the results of the study, a lower gastrointestinal intolerance rate was detected in the GRV threshold 100 mL, monitoring interval for 4 hours protocol (Group 1) than in GRV threshold 200 mL, monitoring interval for 8 hours protocol (Group 2); Group 1 may be preferred renovation.

A Case Report of Toxic Brain Syndrome Caused by Methyl Bromide.

Methyl bromide (CH3Br) is a halogenated aliphatic hydrocarbon that may cause acute and chronic toxicities. We describe a case of a 44-year-old male patient who developed toxic brain syndrome (TBS) and central nervous system (CNS) toxicity after exposure to CH3Br by inhalation. Toxicity began with progressive nervousness, dysarthria and coordination disorder. The complaints on admission to the hospital were speech defect, balance disorder, consciousness disorder and involuntary movements. The patient was treated symptomatically in the intensive care unit (ICU), and organic reasons were excluded. Findings in the magnetic resonance imaging were considered secondary demyelination related to systemic intoxication. Because of the CH3Br, alkylates the crucial sulfhydryl-containing enzymes, N-acetylcysteine was used as a source of sulfhydryl groups for the treatment of the patient. He was hospitalised for nearly 1.5 months in the ICU.

What are the hemodynamic and respiratory effects of passive limb exercise for mechanically ventilated patients receiving low-dose vasopressor/inotropic support?

Passive limb exercises (PLEs) are used widely in the management of unconscious patients and an early start is recommended. The aim of this study was to determine the effects of PLEs on hemodynamic and respiratory parameters in mechanically ventilated critically ill patients receiving low-dose vasopressor/inotropic support. The charts of 120 mechanically ventilated patients who underwent PLEs were evaluated retrospectively between January 2000 and July 2002. Patients were grouped on the basis of administration of vasopressor/inotropic support. Thirty-eight patients did not get vasopressor/inotropic support (group 1) and 82 patients received low-dose vasopressor/inotropic support (dopamine <10 µg/kg/min, noradrenaline/adrenaline <0.1; group 2). Central venous pressure, heart rate, mean arterial pressure, and oxygen saturation were recorded before and immediately after PLEs. After PLEs in group 1 patients, central venous pressure and mean arterial pressure values increased significantly, and in group 2 patients, central venous pressure increased significantly (P < .05). No statistically significant difference was observed in the rate of change of hemodynamic or respiratory parameters between the 2 groups after the PLEs (P > .05). This retrospective study confirmed that PLEs result in similar hemodynamic and respiratory changes in critically ill patients who received low-dose vasopressor/inotropic support versus those who do not.

The effects of remote ischemic preconditioning and N-acetylcysteine with remote ischemic preconditioning in rat hepatic ischemia reperfusion injury model.

BACKGROUND: Remote ischemic preconditioning (RIP) and pharmacological preconditioning are the effective methods that can be used to prevent ischemia reperfusion (IR) injury. The aim of this study was to evaluate the effects of RIP and N-Acetylcysteine (NAC) with RIP in the rat hepatic IR injury model. MATERIALS AND METHODS: 28 rats were divided into 4 groups. Group I (sham): only laparotomy was performed. Group II (IR): following 30 minutes of hepatic pedicle occlusion, 4 hours of reperfusion was performed. Group III (RIP + IR): following 3 cycles of RIP, hepatic IR was performed. Group IV (RIP + NAC + IR): following RIP and intraperitoneal administration of NAC (150 mg/kg), hepatic IR was performed. All the rats were sacrificed after blood samples were taken for the measurements of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and liver was processed for conventional histopathology. RESULTS: The hepatic histopathological injury scores of RIP + IR and RIP + NAC + IR groups were significantly lower than IR group (P = 0.006, P = 0.003, resp.). There were no significant differences in AST and ALT values between the IR, RIP + IR, and RIP + NAC + IR groups. CONCLUSIONS: In the present study, it was demonstrated histopathologically that RIP and RIP + NAC decreased hepatic IR injury significantly.

Ischemic preconditioning attenuates lipid peroxidation and apoptosis in the cecal ligation and puncture model of sepsis.

Sepsis and septic shock are are among the major causes of mortality in intensive care units. The lung and kidney are the organs most affected by sepsis. Evidence exists that lipid peroxidation and apoptosis may be responsible for the high mortality due to sepsis. Ischemic preconditioning (IP) is a method for the protection of tissues and organs against ischemia/reperfusion injury by reducing reactive oxygen species levels, lipid peroxidation and apoptosis. In the present study, the effects of IP were investigated in cecal ligation and puncture (CLP)-induced sepsis in rats. The three groups of animals used in the present controlled study were the sham-operated group (sham, n=7), which only underwent a laparotomy; the sepsis group (sepsis, n=7), which underwent cecal ligation and perforation; and the IP + sepsis group (IP+sepsis, n=7), which underwent CLP immediately prior to the application of three cycles of IP to the hind limb. The study was terminated at 6 h after the induction of CLP. Blood, kidney and lung tissue samples were collected for the determination of serum creatinine, blood urea nitrogen (BUN), neutrophil gelatinase-associated lipocalin (NGAL) and lung tissue malondialdehyde (MDA) levels, as well as histological examination. The serum creatinine, plasma NGAL and lung tissue MDA levels in the sepsis group were significantly increased compared with those in the sham and the IP+sepsis groups (P<0.05). Alveolar macrophage counts, histological kidney and lung injury scores, kidney (caspase 3) and lung tissue immuonreactivity (M30) scores in the sepsis group were also significantly increased compared with those in the sham and IP+sepsis groups (P<0.05). The alveolar macrophage count in the IP+sepsis group was increased compared with that in the sham group (P<0.05). In conclusion, IP inhibits lipid peroxidation and attenuates histological injury and apoptosis in the lung and kidney during sepsis.

The effects of dexmedetomidine on secondary acute lung and kidney injuries in the rat model of intra-abdominal sepsis.

In the present study, the effects of dexmedetomidine on secondary lung and kidney injuries were studied in the rat model of intra-abdominal sepsis by immunohistological and biochemical examinations. We measured serum creatinine, kidney tissue malondialdehide and plasma neutrophil gelatinase-associated lipocalin levels. In order to evaluate tissue injury we determined kidney tissue mononuclear cell infiltration score, alveolar macrophage count, histological kidney and lung injury scores and kidney and lung tissue immunoreactivity scores. We demonstrated that dexmedetomidine attenuates sepsis-induced lung and kidney injuries and apoptosis in the rat model of sepsis. There is still need for comparative studies in order to determine the effects of dexmedetomidine on organ functions in early human sepsis.

Respiratory and hemodynamic responses to mobilization of critically ill obese patients.

PURPOSE: The aim of this study was to investigate the effects of mobilization on respiratory and hemodynamic parameters in critically ill obese patients. METHODS: Critically ill obese patients (n = 31) were included in this retrospective study. Data were collected from patients' files and physiotherapy records of mobilization sessions. Heart rate (HR), systolic/diastolic/mean blood pressure, respiratory rate (RR), and percutaneous oxygen saturation (SpO(2)) were recorded. Cardiorespiratory parameters were collected just prior to the mobilization, just after the completion of the mobilization and after 5 minutes recovery period. Respiratory reserve was calculated before and after the mobilization. RESULTS: A total of 37 mobilization sessions in 31 obese patients (mean age: 63.3 years, mean BMI: 32.2 kg/m(2)) who received physiotherapy were analyzed. Respiratory rate increased significantly after the completion of the mobilization compared to initial values (p < 0.05). SpO(2) significantly increased (p < 0.05) and all other parameters remained similar (p > 0.05) compared to initial values after the recovery period. Mobilization resulted in a significant increase in respiratory reserve (p < 0.05). CONCLUSION: Early mobilization in intensive care unit promotes respiratory reserve in obese patients. We found that mobilization can be performed safely in critically ill obese patients if cardiorespiratory parameters are continuously monitored.

Ischaemic preconditioning attenuates haemodynamic response and lipid peroxidation in lower-extremity surgery with unilateral pneumatic tourniquet application: a clinical pilot study.

INTRODUCTION: The harmful effects of ischaemia-reperfusion on skeletal muscle during extremity surgery can be diminished by using medications or ischaemic preconditioning METHODS: Twenty patients undergoing lower-limb surgery with use of a tourniquet for at least 1 hour were included in the study and randomised into two groups: a control group with only tourniquet application (T group; n=10); and an ischaemic preconditioning plus tourniquet group (IP-T group; n=10). Blood samples were obtained from the femoral vein of the relevant extremity before tourniquet application (baseline), immediately after tourniquet deflation (TD), at 10 minutes after the tourniquet deflation (TD(10min)) in the T group and additionally after ischaemic preconditioning in the IP-T group. Venous blood pH, partial oxygen pressure (P(vO2)), partial carbon dioxide pressure (P(vCO2)), lactate, potassium, sodium and glucose levels were analysed using a blood gas analyser. Plasma thiobarbituric acid reactive substances (TBARS) level, an index of lipid peroxidation and oxidative stress, was measured. Heart rate, noninvasive mean arterial pressure (MAP) and spontaneous breathing rate (SBR) were recorded at baseline, at TD, and TD(1min), TD(5min) and TD(10min). RESULTS: MAP decreased and SBR increased significantly at TD, TD(1min) and TD(5min) compared with baseline, and venous blood TBARS level significantly increased at TD and TD(10min) compared with baseline in the T group (all P<0.05). No significant changes were observed in the IP-T group. Ischaemic preconditioning caused a rise in PvO2 and a decrease in venous blood pH, P(vCO2), and lactate levels, which was significant compared with baseline (P<0.05) CONCLUSION: Ischaemic preconditioning attenuates haemodynamic response and lipid peroxidation during lower-extremity surgery with unilateral tourniquet application.

A possible perianesthetic serotonin syndrome related to intrathecal fentanyl.

Serotonin syndrome occurs with selective serotonin reuptake inhibitors, opioids, and other serotonergic agents. We describe a possible serotonin syndrome related to intrathecal fentanyl in a patient taking multiple drugs and substances such as ergot alkaloids, marijuana, methylenedioxy-N-methylamphetamine, and ephedrine.

The safe limits of mechanical factors in the apnea testing for the diagnosis of brain death.

Apneic oxygenation is an apnea testing method in the diagnosis of brain death. In this method, oxygen (O2) is delivered into the trachea via an O2 catheter (O2C). However, barotrauma may develop during O2 insufflation into the trachea. Oxygen catheter diameters, O2 catheter tip position in the trachea, and O2 flow rate have been proposed as causes of barotrauma. This study was designed to highlight the airway pressure changes during apneic oxygenation in a model consisting of an anesthesia bag, which was connected to a pressure transducer and to an endotracheal tube (ETT). The pressure of the system was monitored while delivering O2 continuously to the system through O2C of different diameters, which were placed in the ETT. Tested variables were ETT/O2C ratio, O2C tip position in ETT (proximal 1/3 of the ETT, mid point of the ETT, and distal 1/3 of the ETT) and O2 flow rate (6, 8, and 10 L min(-1)). The increase in the airway pressure significantly correlated with O2C tip position in ETT (p = 0.017). ETT/O2C ratio smaller than 1.75 caused significantly high airway pressures (p < 0.05). The pressure was significantly higher at the flow rate of 10 L min(-1) O2 compared with the flow rate of 6 L min(-1) O2 (p < 0.01). Thus, ETT/O2C ratio, O2C tip position in ETT and O2 flow rate are the important factors that determine the airway pressure in the trachea during O2 insufflation. In conclusion, overlooked mechanical factors dangerously increase airway pressure during apnea testing.

What is the meaning of standard venous admixture formula results in septic patients?

The standard venous admixture formula is widely used in the bedside assessment of intrapulmonary shunt in intensive care units. The intrapulmonary shunt fraction calculated by the standard venous admixture formula is affected by the systemic oxygen extraction ratio and thus reflects both systemic and intrapulmonary shunts, especially in septic patients with decreased oxygen extraction ratios. The standard venous admixture formula may cause misestimation of the intrapulmonary shunt fraction, especially in septic patients. Inert gas rebreathing techniques and simultaneous measurement of cardiac output by thermodilution and oxygen consumption by indirect calorimetry may be useful in septic patients.