The utility of intra-operative three-dimensional transoesophageal echocardiography for dynamic measurement of stroke volume.

Measurement of left ventricular stroke volume and cardiac output is very important for managing haemodynamically unstable or critically ill patients. The aims of this study were to compare stroke volume measured by three-dimensional transoesophageal echocardiography with stroke volume measured using a pulmonary artery catheter, and to examine the ability of three-dimensional transoesophageal echocardiography to track stroke volume changes induced by haemodynamic interventions. This study included 40 cardiac surgery patients. Haemodynamic variables were measured before and 2 min after haemodynamic interventions, which consisted of phenylephrine 100 µg or ephedrine 5 mg. We used Bland-Altman analysis to assess the agreement between the stroke volume measured by three-dimensional transoesophageal echocardiography and by the pulmonary artery catheter. Polar-plot and 4-quadrant plot analyses were used to assess the trending ability of three-dimensional transoesophageal echocardiography compared with the pulmonary artery catheter. Bias and percentage error were -1.2 ml and 20%, respectively. The concordance rate in the 4-quadrant analysis after phenylephrine and ephedrine administration was 75% and 84%, respectively. In the polar-plot analysis, the angular concordance rate was 66% and 73% after phenylephrine and ephedrine administration, respectively. Three-dimensional transoesophageal echocardiography was clinically acceptable for measuring stroke volume; however, it was not sufficiently reliable for tracking stroke volume changes after haemodynamic interventions.

Preoperative hydroperoxide concentrations are associated with a risk of postoperative complications after cardiac surgery.

This study aimed to assess whether preoperative oxidative stress levels can predict postoperative complications in patients undergoing cardiac surgery. Ninety-five cardiac surgery patients received an assessment of preoperative oxidative stress by measurement of hydroperoxide values in blood via the d-Rom test. Area under the receiver operating characteristic curve and also multivariate logistic regression were used to evaluate the prognostic significance of preoperative hydroperoxide concentrations in predicting the occurrence of major organ morbidity and mortality (MOMM). MOMM included death, deep sternal infection, reoperation, stroke, renal failure requiring haemodialysis and prolonged ventilation (>48 hours). The ability of preoperative hydroperoxide concentrations to predict MOMM was not significantly different from that of the European system for cardiac operative risk evaluation (EuroSCORE) (area under the receiver operating characteristic curve 0.822 versus 0.821 respectively, P=0.983). The optimal threshold value of hydroperoxide concentration to differentiate between patients with and without MOMM was 450 UCarr (sensitivity, 87.0%; specificity, 81.9%). Duration of intensive care unit stay, mechanical ventilation time and hospital stay were significantly longer in patients with preoperative hydroperoxide concentrations ≥450 UCarr (H group) compared to those patients with preoperative hydroperoxide concentrations <450 UCarr (L group). An increase in preoperative hydroperoxide concentrations remained associated with an increased risk of MOMM (odds ratios: 1.01, 95% confidence interval: 1.00 to 1.03) and prolonged intensive care unit stay (odds ratio 1.01, 95% confidence interval: 1.00 to 1.02), after adjusting for age, gender and EuroSCORE. In conclusion, an increased hydroperoxide concentration before cardiac surgery is an independent risk factor for severe postoperative complications.

Systemic vascular resistance has an impact on the reliability of the Vigileo-FloTrac system in measuring cardiac output and tracking cardiac output changes.

BACKGROUND: The aim of this study was to examine the ability of the Vigileo-FloTrac system to measure cardiac output (CO) and track changes in CO induced by increased vasomotor tone, under different states of systemic vascular resistance (SVR). METHODS: Forty patients undergoing cardiac surgery were enrolled. Haemodynamic variables including CO measured by the Vigileo-FloTrac system (version 3.02) (APCO), CO measured by a pulmonary artery catheter (ICO), and SVR index (SVRI) were recorded before (T1) and 2 min after (T2) phenylephrine administration (100 µg). Bland and Altman analysis was used to compare ICO and APCO at T1. We used four-quadrant plots and polar plots to compare the trending abilities between ICO and APCO. Patients were divided into three groups according to the SVRI value at T1, with low (<1200 dyn cm(-5) m(2)), normal (1200-2500 dyn cm(-5) m(2)), and high (>2500 dyn cm(-5) m(2)) SVRI states. RESULTS: A total of 155 paired data were collected. The adjusted percentage error was 46.3%, 26.4%, and 61.4%, and the concordance rate between ΔICO and ΔAPCO was 67.5%, 28.8%, and 7.7% in the low, normal, and high SVRI state, respectively. The polar plot analysis showed that the mean angular bias was -22.3°, -46.0°, and -3.51°, and the radial limits of agreement were 70°, 85°, and 87°, in the low, normal, and high SVRI state, respectively. CONCLUSIONS: These results indicate that the reliability of the Vigileo-FloTrac system to measure CO and track changes in CO induced by phenylephrine administration was not clinically acceptable.

Airway problems related to laryngeal mask airway use associated with an undiagnosed epiglottic cyst.

This report describes airway management difficulties in a patient with an asymptomatic and undiagnosed epiglottic cyst. Mask ventilation after induction of general anesthesia was uneventful. Insertion of an LMA resulted in inadequate ventilation. Fiberoptic intubation through an intubating LMA was impossible because the LMA pushed the cyst into the laryngeal inlet. Fibreoptic intubation, assisted by the use of a direct laryngoscope without the LMA was uneventful. Preoperative craniocervical scans performed for assessment of other conditions may reveal asymptomatic pathology in the airway.

Quantitation of nucleotides, nucleosides and bases in antemortem and postmortem bloodstains by high-performance liquid chromatography.

Ante- and post-mortem bloodstains prepared from the blood of volunteers and corpses were analysed for ATP and its related compounds by reversed-phase high-performance liquid chromatography (HPLC). The results showed that (1) ATP was present in a large amount in antemortem bloodstains but not in postmortem stains, (2) AMP, adenosine, inosine, hypoxanthine, xanthine and uracil either were not detected or were detected in smaller amounts in antemortem than in postmortem bloodstains, and (3) ADP was present in both ante- and post-mortem bloodstains. These differences suggest that quantitation of these compounds may be useful in identifying whether bloodstains are ante- or post-mortem.

Re-evaluation of death by asphyxia based on cerebral blood flow (VII)--on the information on electric potentials obtained from deep electroencephalographic electrodes.

The author presents electroencephalographic patterns (a physiological parameter of the brain function observed at rapid and fatal drowning of rabbits), cerebral blood flow (CBF) which support the physiological activities of the brain, and the relationship between systemic respiration and circulation with special reference to changes in the electrical potentials detected by deep electroencephalographic electrodes. The possibility of diagnosis of fatal drowning is examined, based on the results.

Cerebral blood flow and serum haptoglobin in the diagnosis of death by rapid drowning.

Diagnosis of death and the feasibility of resuscitation in cases of acute drowning in fresh water (FW) or sea water (SW) inhalation in rabbits were evaluated using cardiopulmonary function monitoring, measurement of cerebral blood flow (CBF) and determination of haptoglobin (HP). Death took place more quickly in FW drowning, two to five minutes, as compared with four to seven minutes required in SW drowning. In view of the CBF patterns in the brain circulation, many problems exist regarding the judgement of the point of death and the applicability of resuscitation. However, it is considered that brain damage in SW drowning occurs more rapidly than in FW drowning.