Hyperchloremic metabolic acidosis due to saline absorption during laser enucleation of the prostate: a case report.

BACKGROUND: Recent technological advancements have enabled the use of electrolyte solutions such as saline or buffered electrolyte solution during transurethral resection or laser enucleation of the prostate. However, saline absorption may cause hyperchloremic metabolic acidosis. CASE PRESENTATION: A male in his late seventies underwent holmium laser enucleation of the prostate under a combination of subarachnoid block and general anesthesia. Intraoperatively, abdominal distension prompted the attending anesthesiologist to consider the possibility of SGA malposition, and the trachea was intubated. Oropharyngeal and neck edema was observed, and laboratory examination revealed considerable acidosis with hyperchloremia. Further evaluation confirmed the absorption of a large amount of saline into the circulation via the perforated bladder. Application of the simplified Stewart approach clearly suggested that hyperchloremia was the principal cause of metabolic acidosis. The dilution of albumin attenuated acidosis. CONCLUSIONS: Absorption of normal saline during laser enucleation of prostate caused hyperchloremic metabolic acidosis and airway edema.

Comparison of volume and hemodynamic effects of crystalloid, hydroxyethyl starch, and albumin in patients undergoing major abdominal surgery: a prospective observational study.

BACKGROUND: The volume effect of iso-oncotic colloid is supposedly larger than crystalloid, but such differences are dependent on clinical context. The purpose of this single center observational study was to compare the volume and hemodynamic effects of crystalloid solution and colloid solution during surgical manipulation in patients undergoing major abdominal surgery. METHODS: Subjects undergoing abdominal surgery for malignancies with intraoperative goal-directed fluid management were enrolled in this observational study. Fluid challenges consisted with 250 ml of either bicarbonate Ringer solution, 6% hydroxyethyl starch or 5% albumin were provided to maintain optimal stroke volume index. Hematocrit derived-plasma volume and colloid osmotic pressure was determined immediately before and 30 min after the fluid challenge. Data were expressed as median (IQR) and statistically compared with Kruskal-Wallis test. RESULTS: One hundred thirty-nine fluid challenges in 65 patients were analyzed. Bicarbonate Ringer solution, 6% hydroxyethyl starch and 5% albumin were administered in 42, 49 and 48 instances, respectively. Plasma volume increased 7.3 (3.6-10.0) % and 6.3 (1.4-8.8) % 30 min after the fluid challenge with 6% hydroxyethyl starch and 5% albumin and these values are significantly larger than the value with bicarbonate Ringer solution (1.0 (- 2.7-2.3) %) Colloid osmotic pressure increased 0.6 (0.2-1.2) mmHg after the fluid challenge with 6% hydroxyethyl starch and 0.7(0.2-1.3) mmHg with 5% albumin but decreased 0.6 (0.2-1.2) mmHg after the fluid challenge with bicarbonate Ringer solution. The area under the curve of stroke volume index after fluid challenge was significantly larger after 6% hydroxyethyl starch or 5% albumin compared to bicarbonate Ringer solution. CONCLUSIONS: Fluid challenge with 6% hydroxyethyl starch and 5% albumin showed significantly larger volume and hemodynamic effects compared to bicarbonate Ringer solution during gastrointestinal surgery. TRIAL REGISTRATION: UMIN Clinical Trial Registry UMIN000017964. Registered July 01, 2015.

Association of Oral Intake and Transient Mixed Venous Oxygen Desaturation in Patients Undergoing Fast-Track Postoperative Care After Open-Heart Surgery.

OBJECTIVE: The impact of early resumption of oral intake after cardiac surgery on hemodynamics has not been characterized. The authors examined the effects of early oral intake on the oxygen supply-demand relationship in patients undergoing on-pump cardiac surgery in an early recovery after surgery program. DESIGN: Prospective data were collected in postcardiac surgical patients in a multidisciplinary intensive care unit (ICU) during an 18-month period. SETTING: Single institution study. PARTICIPANTS: Forty-three patients who underwent either mitral or aortic valve repair and were successfully liberated from ventilatory support within 10 hours after surgery. INTERVENTIONS: Patients were either allowed to resume oral intake on the morning of the first postoperative day or not at the discretion of the surgical team after extubation. MEASUREMENTS AND MAIN RESULTS: The oxygen supply-demand relationship was assessed continuously with cardiac index and mixed venous oxygen saturation (SvO2). Among the subjects, 22 patients were allowed to eat, and transient SvO2 decrease was noted in 13 patients. All transient SvO2 decreases occurred in the patients with early oral intake. The hemodynamic status and oxygen supply-demand relationship did not differ between the patients with and without transient SvO2 decrease. All the subjects were discharged successfully from the ICU on the first postoperative day, and the length of hospital stay was similar irrespective of SvO2 decrease after early oral intake. CONCLUSIONS: Early oral intake shortly after extubation was associated with transient but significant SvO2 decrease in patients who underwent fast-track recovery after open-heart surgery. Because this phenomenon did not negatively affect the postoperative outcome, early oral intake may not be harmful.

The comparison between stroke volume variation and filling pressure as an estimate of right ventricular preload in patients undergoing renal transplantation.

PURPOSE: The purpose of this prospective, observational study was to respiratory variation of stroke volume (stroke volume variation, SVV) against central venous pressure (CVP) and pulmonary artery diastolic pressure (PADP) as an estimate of right and left ventricular preload. METHODS: With IRB approval and informed consent, 31 patients undergoing living related renal transplantation were analyzed. Under general anesthesia with positive pressure ventilation, stroke volume index and SVV were continuously monitored with FloTrac/Vigileo monitor. Right ventricular end-diastolic volume index (RVEDVI) as well as CVP and PADP were continuously monitored with volumetric pulmonary artery catheter. Data of every 30 min interval were used for analysis. The relationship between RVEDVI and CVP, PADP, SVV was analyzed with non-linear regression and the goodness-of-fit was assessed with coefficient of determination (R(2)) of each regression curve. The ability of CVP, PADP and SVV to correctly differentiate RVEDVI <100, <120 or >138 ml/m(2), which were used to guide fluid administration, was also assessed with ROC analysis. RESULTS: Three hundred forty-eight data sets were obtained and analyzed. The goodness of fit between RVEDVI and SVV (R(2)) = 0.48) was better than that between RVEDVI and CVP or PADP (R(2)) = 0.19 and 0.33, respectively). The area under the ROC curve of SVV was significantly high compared to CVP or PADP. CONCLUSIONS: This study confirmed the theoretical framework of right ventricular preload and ventricular filling pressure and respiratory variation of stroke volume. The result also suggests that SVV can correctly predict preload status compared to pressure-based indices.

Pros and cons of tetrastarch solution for critically ill patients.

Proper fluid management is crucial for the management of critically ill patients. However, there is a continuing debate about the choice of the fluid, i.e., crystalloid vs. colloid. Colloid solution is theoretically advantageous to the crystalloid because of larger volume effect and less interstitial fluid accumulation, and hydroxyethyl starch (HES) is most frequently used for perioperative setting. Nevertheless, application of HES solution is relatively limited due to its side effects including renal toxicity and coagulopathy. Since prolonged presence of large HES molecule is responsible for these side effects, rapidly degradable HES solution with low degree of substitution (tetrastarch) supposedly has less potential for negative effects. Thus, tetrastarch may be more frequently used in the ICU setting. However, several large-scale randomized trials reported that administration of tetrastarch solution to the patients with severe sepsis has negative effects on mortality and renal function. These results triggered further debate and regulatory responses around the world. This narrative review intended to describe the currently available evidence about the advantages and disadvantages of tetrastarch in the ICU setting.

Low molecular weight pentastarch is more effective than crystalloid solution in goal-directed fluid management in patients undergoing major gastrointestinal surgery.

BACKGROUND: This prospective observational study compared the volume effect between hydroxyethyl starch (HES) and crystalloid solution and its context dependency in intraoperative goal-directed fluid management. METHODS: With institutional review board (IRB) approval, 35 patients undergoing major gastrointestinal surgery were enrolled. Fluid challenge consisting of 250 ml of either bicarbonate Ringer solution (BRS) or low molecular weight pentastarch (HES 70/0.5) was given to maintain stroke volume index >35 ml/m2. The context of fluid challenge was classified as related to either epidural block (EB) or blood loss (BL) or as nonspecific. The primary end point was the interval between index fluid challenge and the next fluid challenge, and the secondary end point was the hemodynamic parameter at the end of fluid challenge. Differences in these parameters in each clinical context were compared between BRS and HES 70/0.5. A p value <0.05 was considered statistically significant. RESULTS: Eighty-eight, 77, and 127 fluid challenges were classified as related to EB and BL and as nonspecific, respectively. In the nonspecific condition, the median (range) interval after fluid challenge with HES 70/0.5 and BRS was 45 (11-162) min and 18 (8-44) min, respectively, and the difference was statistically significant. Also, mean arterial pressure and stroke volume index significantly increased, whereas stroke volume variation significantly decreased after fluid challenge with HES 70/0.5 compared with BRS. Such differences were not observed in the other situations. CONCLUSIONS: HES 70/0.5 exerted larger volume effects than did crystalloid under nonspecific conditions. However, similar volume effects were observed during volume loss and extensive sympathetic blockade.

Evaluation of multiwave pulse total-hemoglobinometer during general anesthesia.

The purpose of this prospective study was to evaluate the accuracy and trending ability of a four-wavelength pulse-total hemoglobinometer that continuously and noninvasively measures hemoglobin in surgical patients. With IRB approval and informed consent, spectrophotometric hemoglobin (SpHb) was measured with a pulse-total hemoglobinometer manufactured by Nihon Kohden Corp (Tokyo, Japan) and compared to the CO-oximeter equipped with blood gas analyzer. Two hundred twenty-five samples from 56 subjects underwent analysis. Bland-Altman analysis revealed that the bias ± precision of the current technology was 0.0 ± 1.4 g/dl and -0.2 ± 1.3 g/dl for total samples and samples with 8 < Hb < 11 g/dl, respectively. The percentages of samples with intermediate risk of therapeutic error in error grid analysis and the concordance rate of 4-quadrant trending assay was 17 % and 77 %, respectively. The Cohen kappa statistic for Hb < 10 g/dl was 0.38, suggesting that the agreement between SpHb and CO-oximeter-derived Hb was fair. Collectively, wide limits of agreement, especially at the critical level of hemoglobin, and less than moderate agreement against CO-oximeter-derived hemoglobin preclude the use of the pulse-total hemoglobinometer as a decision-making tool for transfusion.

[Anesthetic management of patients with pulmonary arterial hypertension (PAH)].

BACKGROUND: Pulmonary arterial hypertension (PAH) is associated with significant perioperative risk due to the severity of cardiac dysfunction related to the RV Tei index greater than 0.83. We evaluated the car- diovascular function during anesthesia to elucidate the characteristics of severity of PAH. METHODS: Nine patients undergoing central venous catheterization under general anesthesia (seven patients) and local anesthesia with sedation (two patients) were studied. RV Tei index of five patients were greater than 0.83 (severe) and in four patients RV Tei index was below 0.83 (moderate). Bioimpedance method was used to determine stroke volume (SV) and cardiac output (CO) non-invasively throughout anesthesia. The correlation between the changes in SV and CO was evaluated by using least squares method. RESULTS: Demographic data showed mean age of 16.6 years, height of 146.9 cm and weight of 39.7 kg. Correlation coefficient of SV and CO in the patients with severe cardiac dysfunction was 0.0-0.21, while in those with moderate cardiac dysfunction it was 0.49-0.93. CONCLUSIONS: In patients with severe PAH, it was demonstrated that CO is maintained by the change in heart rate (HR) but not by SV It is suggested that the control of HR in patients with PAH is of clinical importance in order to maintain CO, if RV index is greater than 0.83.

[Semi-invasive monitoring of cardiac output in renal transplantation by a new device using arterial pressure waveform analysis compare with intermittent pulmonary thermodilution].

BACKGROUND: Clinical usefulness of PA catheter is controversial. We compared a new semi-invasive device (FloTrac/Vigileo) using arterial pressure waveform analysis for CO measurement in patients undergoing renal transplantation with bolus thermodilution method. Simultaneously CCO was measured, and we compared CCO with that obtained by bolus thermodilution method. METHODS: Forty seven patients undergoing renal transplantation were enrolled. A PAC was inserted and radial arterial access was used for semi-invasive determination of CO (APCO) with the Vigileo. CO was measured simultaneously by bolus thermodilution and the Vigileo technique, and after starting operation, volume loading, before surgery, and other points were measured over 1 hour during measurements. And CCO was measured simultaneously at all points. STATISTICAL ANALYSIS: Statistical analysis was performed using the method described by Bland and Altman. Bias was defined as the mean difference between the volumes obtained by pulmonary artery thermodilution and those by arterial pressure waveform analysis. Precision was expressed by the upper and lower limits of agreement. RESULTS: Means of age, height and weight were 45 years, 163.8 cm and 59.2 kg, respectively. Regression analysis of CO; APCO and ICO showed y = 0.8x + 2.2, R2 = 0.57. CCO and ICO; y = 0.8x + 1.1, R2 = 0.74. Average of APCO and ICO; bias = -0.65. SD = 1.54 average of CCO and ICO; bias = 0.38, SD = 1.23. CONCLUSIONS: In renal transplantation, CO measured by a new semi-invasive arterial pressure waveform analysis device showed good agreement with the volume obtained by intermittent pulmonary artery thermodilution method.

[A pilot assessment of the FloTrac cardiac output monitoring system comparing with pulmonary artery catheter method by three versions].

BACKGROUND: Clinical significance of PA catheter is controversial. FloTrac sensor bases its calculations on arterial waveform characteristics. We conducted a pilot assessment of the FloTrac sensor by three versions comparing with pulmonary artery catheter (PCA) methodology. METHODS: Five patients undergoing cardiac surgery and four patients undergoing renal transplantation were enrolled. A PAC was inserted and radial arterial access was used for semi-invasive determination of CO (APCO) with the Vigileo. CO was measured simultaneously by bolus thermodilution and the Vigileo technique, and CCO was measured simultaneously. RESULTS: The correlation with output obtained by FloTrac and obtained by PCA is better with the newer version. Bland Altman analyses demonstrated better agreement between FloTrac and PCA methodology of the newer version. CONCLUSIONS: CO measured by a new semi-invasive arterial pressure waveform analysis device showed better agreement with pulmonary artery thermodilution measurement of the newer version.

[Anesthetic management of caesarean section following the Fontan procedure by using TaskForce Monitor].

The Fontan procedure is performed for patients with a corrected transposition of great arteries, and pregnancies following this surgery are likely to increase in number. We present a parturient with the Fontan physiology. In this case, we used thoracic bio-impedance cardiac output monitoring system "TaskForce Monitor". It was shown that the cardiovascular management by using TaskForce Monitor was useful because of the non-invasive beat-to-beat cardiac output monitoring.

[Cardiovascular effects of human atrial natriuretic peptide during pediatric renal transplantation].

BACKGROUND: We evaluated the cardiovascular effects of human atrial natriuretic peptide (hANP) in the pediatric recipients undergoing renal transplantation. METHODS: Anesthesia was maintained by inhalation of nitrous-oxide and isoflurane in oxygen. Intravenous infusion of hANP at a rate of 0.05 microg x kg(-1) x min(-1) was started on the anastomosis of the renal artery after the fresh frozen plasma had been loaded to achieve PCWP above 17 mmHg. We examined cardiovascular changes by using a pulmonary artery catheter and transesophageal echocardiography. The measurements were done before and after 15 minutes of hANP infusion. RESULTS: An increase in CI and a reduction in PCWP were significant. CONCLUSIONS: The low-dose infusion of hANP was useful in pediatric recipients undergoing renal transplantation for the optimal anesthetic care in view of the improvement of cardiovascular functions.

[Cardiovascular effects of human atrial natriuretic peptide during renal transplantation].

BACKGROUND: We evaluated the cardiovascular effects of human atrial natriuretic peptide (hANP) in the recipients of renal transplantation. METHODS: Anesthesia was maintained by inhalation of nitrous-oxide and isoflurane in oxygen, with epidural block. The recipients were divided into three groups; one group received no hANP infusion as control and the other groups received continuous infusion of hANP at the rate of either 0.05 microg x kg(-1) x min(-1) or 0.1 microg x kg(-1) x min(-1). Intravenous infusion of hANP was started at the anastomosis of renal artery after the fresh frozen plasma was loaded to achieve PCWP over 17 mmHg. In each group, we examined cardiovascular changes by using a pulmonary artery catheter and transesophageal echocardiography. The measurements were done before and after 15 minutes of hANP infusion. RESULTS: In comparison with control, the decreases in PCWP and CVP were significant in the 0.1 microg x kg(-1) x min(-1) group. An increase in CI and the reduction of CVP were significant in 0.05 microg x kg(-1) x min(-1) group, when compared with control group. In the 0.1 microg x kg(-1) x min(-1) group, the reductions of PCWP and CVP and MAP were significant, but the significant increase in CI was characteristic in the 0.05 microg x kg(-1) x min(-1) group. CONCLUSIONS: We conclude that the low-dose infusion of hANP in the recipients of renal transplantation is useful for the optimal anesthetic care because of the cardiovascular improvement.