Takashige Yamada

Multicenter study verifying a method of noninvasive continuous cardiac output measurement using pulse wave transit time: a comparison with intermittent bolus thermodilution cardiac output.

BACKGROUND: Many technologies have been developed for minimally invasive monitoring of cardiac output. Estimated continuous cardiac output (esCCO) measurement using pulse wave transit time is one noninvasive method. Because it does not require any additional sensors other than those for conducting 3 basic forms of monitoring (electrocardiogram, pulse oximeter wave, and noninvasive (or invasive) arterial blood pressure measurement), esCCO measurement is potentially useful in routine clinical circulatory monitoring for any patient including low-risk patients. We evaluated the efficacy of noninvasive esCCO using pulse wave transit time in this multicenter study. METHODS: We compared esCCO and intermittent bolus thermodilution cardiac output (TDCO) in 213 patients, 139 intensive care units (ICUs), and 74 operating rooms (ORs), at 7 participating institutions. We performed electrocardiogram, pulse oximetry, TDCO, and arterial blood pressure measurements in patients in ICUs and ORs; a single calibration was performed to measure esCCO continuously. TDCO measurement was performed once daily for ICU patients and every hour for OR patients, and just before the removal of the pulmonary arterial catheter from patients in both the ICU and OR. We evaluated esCCO against TDCO with correlation analysis and Bland and Altman analysis and also assessed the change of bias over time. Furthermore, we inspected the impact of change in systemic vascular resistance (SVR) on change in bias because abnormal SVR was assumed to be a factor contributing to the change of the bias. RESULTS: From among 588 esCCO and TDCO datasets (excluding calibration points), 587 datasets were analyzed for 213 patients. The analysis results show a correlation coefficient of 0.79 (P < 0.0001, 95% confidence limits of 0.756–0.819), a bias (mean difference between esCCO and TDCO) of 0.13 L/min (95% confidence interval of bias 0.04–0.22 L/min), and a precision (1 SD) of 1.15 L/min (95% prediction interval was −2.13 to 2.39 L/min). There were no significant differences among 3 defined time intervals over 48 hours after calibration (repeated-measures analysis of variance P = 0.781) in the ICU. The influence of SVR on esCCO analysis showed a correlation coefficient between SVR and an error of 0.37 (P < 0.0001, 95% confidence interval 0.298–0.438). CONCLUSION: The efficacy of noninvasive esCCO technology was compared with TDCO in 213 cases. Five hundred eighty-seven datasets comparing esCCO and TDCO showed close correlation and small bias and precision, which were comparable to current arterial waveform analysis technologies.

Transient hemodynamic change and accuracy of arterial blood pressure-based cardiac output.

BACKGROUND: The purpose of this study was to determine the effects of transient arterial blood pressure change on the accuracy of the FloTrac™/Vigileo™ monitor (Edwards Lifesciences, Irvine, CA). METHODS: We compared stroke volume determined with the FloTrac/Vigileo with Doppler during anesthetic induction in 20 patients undergoing abdominal aortic reconstruction. RESULTS: The difference between the FloTrac measurements of stroke volume and the Doppler measurements of stroke volume was −7.5 ± 20.5 mL (mean ± SD) before induction, 0.3 ± 14.9 before laryngoscopy, 17.5 ± 26.9 during laryngoscopy, 20.5 ± 27.6, and −4.5 ± 16.4 mL 3 minutes after endotracheal tube placement. CONCLUSION: The FloTrac/Vigileo measured stroke volume with reasonable accuracy during transient hypotension but overestimated stroke volume during transient hypertension.

Neutrophil gelatinase-associated lipocalin regulates gut microbiota of mice.

Because neutrophil gelatinase‐associated lipocalin (NGAL) is known to provide significant bacteriostatic effects during infectious conditions, we tested the hypothesis that this protein is up‐regulated and secreted into the intraluminal cavity of the gut under critically ill conditions and is thus responsible for the regulation of bacterial overgrowth.

Intra- and postoperative low-dose ketamine for adolescent idiopathic scoliosis surgery: a randomized controlled trial.

In this randomized controlled trial, we examined whether intra‐ and postoperative infusion of low‐dose ketamine decreased postoperative morphine requirement and morphine‐related adverse effects as nausea and vomiting after scoliosis surgery.

Response Time of Different Methods of Cardiac Output Monitoring During Cardiopulmonary Resuscitation and Recovery

partial pressure (PETCO2) and mixed venous hemoglobin oxygen saturation (SvO2) also were continuously monitored and recorded. During the laparotomy, hypotension and tachycardia were noted and were accompanied by facial flushing. This was diagnosed as mesenteric traction syndrome and was treated with fluid administration and intermittent intravenous ephedrine. During this period, high cardiac output was recorded with all devices. The maximal values recorded were 6.9 L/min, 9.2 L/min, 17.4 L/min, and 17.9 L/min via the EDM, NICO, STAT CCO, and trend CCO monitors, respectively. At this point, the SvO2 was 89% and VCO2 was 137 mL/min. These symptoms eventually disappeared, and the patient’s CO subsequently stabilized (measured as 5.5 L/min, 5.1 L/min, 10.1 L/min, and 11.3 L/min via the EDM, NICO, STAT CCO, and CCO monitors, respectively; SvO2 85%, VCO2 126 mL/min. The CO at this point as measured with a bolus thermodilution was 7.0 L/min. During surgical exposure of the aortic aneurysm, a sudden onset of ventricular premature contraction was followed by sustained ventricular tachycardia (VT). Because initial DC cardioversion failed to stop the VT, phenylephrine, lidocaine, nitroglycerin, and epinephrine were administered while closed-chest compression was provided. During CPR, the patient was manually ventilated to ensure adequate ventilation. The minute volume provided during CPR was between 11 L/min and 12 L/min. The third DC cardioversion finally restored the patient to sinus rhythm. The duration of VT was 9 minutes, and chest compression provided a systolic pressure of more than 60 mmHg and diastolic pressure of more than 20 mmHg during CPR. The trend for the EDM, NICO, STAT CCO, and trend CCO monitors are summarized in Figure 1, along with PETCO2 and SvO2 during the CPR period. The CO measured with EDM varied from 0 to 2.5 L/min, and the signal of descending aortic blood flow caused by chest compression was clearly visible during this event using EDM. Three rebreathing cycles were used with a NICO monitor during CPR. The first rebreathing cycles were applied at 2 minutes after the onset of VT and the CO and VCO2 were reported as 2.9 L/min and 104 mL/min, respectively. The second cycle was applied 5 minutes after the onset of VT and failed to estimate the CO. The third rebreathing cycle was applied at 8 minutes after the onset of VT, and the CO and VCO2 were

Psychological and endocrine factors and pain after mastectomy

This prospective study was designed to examine the associations of demographic, clinical, psychological and neuroendocrine factors with acute and chronic post‐operative pain following partial mastectomy.

Descending aortic blood flow during aortic cross-clamp indicates postoperative splanchnic perfusion and gastrointestinal function in patients undergoing aortic reconstruction

BACKGROUND The purpose of this observational study was to investigate the relationship between splanchnic and renal blood flow during infrarenal aortic cross-clamp (XC) and postoperative gastrointestinal perfusion and function. METHODS Descending aortic blood flow (DABF) was continuously monitored with an oesophageal Doppler monitor (Cardio-Q, Deltex Ltd, Chichester, UK) in 31 patients undergoing elective abdominal aortic aneurysm repair. Cardiac output (CO) was determined by indocyanine green dilution before, during, and after XC. Perioperative gastrointestinal perfusion was assessed by gastric intramucosal pH (pHi, Tonocap, GE Healthcare, Helsinki, Finland). Postoperative gastrointestinal recovery was assessed by the number of postoperative days until the patient successfully resumed solid food intake. The relationship between the mean DABF during XC and gastric pHi after XC release and postoperative gastrointestinal recovery was analysed with Spearmans correlation coefficient. RESULTS accounted for ∼ 55% of CO during XC and significantly decreased during XC, despite arterial pressure remaining within an optimal range. There were two distinct relationships between DABF during XC and gastric pHi after XC release. Gastric pHi steeply and linearly declined when indexed DABF was below 0.82 litre min(-1) m(-2). Above this critical value, there was no linear relationship between them. The duration of postoperative gastrointestinal dysfunction was inversely correlated with the mean DABF during XC. The best cut-off value of the mean indexed DABF during XC to prevent prolonged gastrointestinal dysfunction was 1.2 litre min(-1) m(-2). CONCLUSIONS Decreased DABF during XC associates splanchnic hypoperfusion after XC release and delayed recovery of gastrointestinal function.

Can mixed venous hemoglobin oxygen saturation be estimated using a NICO monitor

BACKGROUND: We hypothesized that mixed venous hemoglobin oxygen saturation (SvO2) can be estimated by calculation from CO2 production, cardiac output, and arterial oxygen saturation measured using a noninvasive cardiac output (NICO) monitor (Novametrix-Respironics, Wallingford, CT). METHODS: Twenty-three patients undergoing aortic aneurysm repair underwent SvO2 monitoring using a pulmonary artery catheter and cardiac output monitoring using a NICO monitor. The estimated SvO2 value calculated from NICO monitor-derived values was compared with the SvO2 value measured using a pulmonary artery catheter. The accuracy of this estimation was analyzed with Bland-Altman method. The ability of this estimation to track the change of SvO2 was also evaluated using correlation analysis to compare the changes of estimated SvO2 and measured SvO2. RESULTS: The bias ± limits of agreement of the estimated SvO2 against measured SvO2 was −2.1% ± 11.2%. The change of estimated SvO2 was modestly correlated with the change of measured SvO2. CONCLUSIONS: SvO2 derived from the values measured by the NICO monitor cannot be used interchangeably with the values measured spectrophotometrically using the pulmonary artery catheter. More refinement is required to obtain more reliable estimate of SvO2 less invasively. However, large changes of SvO2 may be detected with this method and can be used as a precautionary sign when the balance between oxygen supply and demand is compromised without inserting a central venous catheter.

The effects of epidural anesthesia on growth of Escherichia coli at pseudosurgical site: The roles of the lipocalin-2 pathway

BACKGROUND:Neutrophil-derived lipocalin-2 exerts bacteriostatic effects through retardation of iron uptake by the Gram-negative organisms like Escherichia coli. We tested the hypothesis that the expression of lipocalin-2, a bacteriostatic protein, was upregulated by induction of surgical site infection (SSI) with E coli in healthy and diseased rats and that epidural anesthesia modulated its expression. METHODS:Male Wistar rats were randomized into a healthy or disease group, the latter of which was administered lipopolysaccharide. Both groups were further divided into 3 subgroups, the control, saline, and lidocaine groups: group healthy control (n = 10), healthy saline (n = 10), and healthy lidocaine (n = 10) versus group disease control (n = 15), disease saline (n = 18), and disease lidocaine (n = 19), respectively. While saline was epidurally administered to the control and saline groups, lidocaine was administered to the lidocaine groups. Except for the control groups, E coli was injected to the pseudosurgical site to mimic SSI after abdominal surgery. Plasma concentrations of inflammatory cytokine and lipocalin-2 were measured. At 72 hours, the surgical site tissues were obtained to evaluate mRNA expression of lipocalin-2 and E coli DNA expression. RESULTS:All disease subgroups showed markedly increased plasma inflammatory cytokines versus the healthy subgroups. Among the disease subgroups, plasma concentrations of lipocalin-2 and tissue mRNA expression of lipocalin-2 were significantly increased in group disease lidocaine versus the others. Concurrently, E coli DNA expression in the tissue specimens was also significantly lower in group disease lidocaine as compared with group disease saline. CONCLUSIONS:Epidural anesthesia was associated with an increase in the expression lipocalin-2 and a decrease in the expression of E coli DNA at pseudosurgical sites in sick but not healthy rats. These observations suggest a potential mechanism by which epidural anesthesia could reduce the risk of SSI.

Difference in autologous blood transfusion-induced inflammatory responses between acute normovolemic hemodilution and preoperative donation

PurposeThe inflammatory response triggered by transfusion is implicated in the pathophysiology of transfusion-related immunomodulation. The authors hypothesized that two distinctive autotransfusion methods, acute normovolemic hemodilution (ANH) and preoperative donation (PD), have different influences on both inflammatory mediator generation during storage and the inflammatory response after a transfusion. The purpose of this study was to compare the plasma concentrations of neutrophil elastase (NE), interleukin (IL)-6, IL-8, and IL-10 in patients who underwent either of these two autologous transfusion methods.MethodsWith institutional review board approval, the plasma concentrations of the above inflammatory mediators were determined in 23 patients with ANH and 8 patients with PD at the following time points: after anesthetic induction, at the end of the operation, and the morning of postoperative day 1. The concentrations of these inflammatory mediators were also measured in the donated blood obtained by either ANH or PD before retransfusion.ResultsThe mean storage durations were 3.7 h and 6.1 days for ANH and PD, respectively. Higher concentrations of NE and IL-10 were detected in the PD blood than in the ANH blood. Long duration of storage and/or low temperature may have been responsible for the increased NE and IL-10 concentrations in the PD blood. However, the difference between the two groups in the extent of increased plasma concentrations of these inflammatory mediators was not statistically significant.ConclusionInflammatory mediators were significantly increased in PD blood during storage compared to the blood obtained by ANH. However, their effects on the inflammatory response elicited in the recipients were not significantly different.