Development and comparison of an esophageal Doppler monitoring-based treatment algorithm with a heart rate and blood pressure-based treatment algorithm for goal-directed fluid therapy in anesthetized dogs: A pilot study.

The objective of this pilot study was to determine the feasibility of a study comparing the efficacy of an esophageal Doppler monitor (EDM)-based fluid therapy algorithm with a heart rate (HR)- and mean arterial blood pressure (MAP)-based algorithm in reducing hypotension and fluid load in anesthetized dogs. Client-owned dogs undergoing general anesthesia for surgical procedures were randomized to two groups. An EDM probe for monitoring blood flow in the descending aorta was placed in each dog before receiving a crystalloid bolus (5 mL/kg) over 5 min. Fluids were repeated in case of fluid responsiveness defined by increasing Velocity Time Integral (VTI) ≥ 10% in group EDM and by decreasing HR ≥ 5 beats/min and/or increasing MAP ≥ 3 mmHg in group standard. The feasibility outcomes included the proportion of dogs completing the study and the clinical applicability of the algorithms. The clinical outcomes were the total administered fluid volume and the duration of hypotension defined as MAP < 60 mmHg. Data was compared between groups with Mann-Whitney U-test. p < 0.05 were deemed significant. Of 25 dogs screened, 14 completed the study (56%). There were no differences in the proportion of recorded time spent in hypotension in group standard [2 (0-39)% (median (range))] and EDM [0 (0-63) %, p = 1], or the total volume of fluids [standard 8 (5-14) mL/kg/h, EDM 11 (4-20) mL/kg/h, p = 0.3]. This study declined the feasibility of a study comparing the impact of two newly developed fluid therapy algorithms on hypotension and fluid load in their current form. Clinical outcome analyses were underpowered and no differences in treatment efficacy between the groups could be determined. The conclusions drawn from this pilot study provide important information for future study designs.

Usability of Esophageal Doppler for Monitoring of Concealed Retroperitoneal Hemorrhage during Laparoscopy Assisted Subtotal Gastrectomy / 대한구급학회지

Hemodynamic monitoring is an essential element in the management of perioperative patients. In addition, anesthesiologists routinely used blood pressure (invasive or non invasive), heart rate, urinary output and central venous pressure as monitoring modalities. Esophageal doppler monitoring, as a minimally invasive hemodynamic assessment tool, has a good correlation with pulmonary artery catheterization in measuring cardiac output. We experienced a case of concealed retroperitoneal hemorrhage in a patient who underwent a laparoscopic subtotal gastrectomy. When surgeons tried to close trocar sites, the patient's blood pressure dropped rapidly. At laparoscopy, we could not find gross bleeding. However, we could detect hypovolemia by esophageal doppler monitoring (CardioQ, Deltex(TM), UK). The procedure was converted to open laparotomy. Thereafter, we could find retroperitoneal hemorrhage, and vascular repair was done successfully. The patient recovered without any other complications.

The hemodynamic effects of a reversed Trendelenburg in elderly patients with increased cardiac risk during laparoscopic cholecystectomy.

BACKGROUND: We studied the hemodynamic changes induced by pneumoperitoneum and a reversed Trendelenburg in elderly patients with increased cardiac risk (ASA class III; n = 30; age 70.8 +/- 4.9 years, mean +/- SD) and compared the results with elderly patients at normal risk (ASA class II; n = 30; age 69.2 +/- 4.1 years) during laparoscopic cholecystectomy. METHODS: The transesophageal Doppler monitor was performed after induction of general anesthesia (pre-incision), after onset of pneumoperitoneum (insufflation), after head-up (20degrees) and a left lateral tilt (15degrees) (reversed Trendelenburg) and after deflation and horizontal position (desufflation). Mean arterial pressure (MAP), heart rate, cardiac index (CI) and systemic vascular resistance (SVR) were measured, respectively. RESULTS: Induction of pneumoperitoneum and head-up tilt in patients with cardiac risk resulted significantly in a decrease in CI and an increase in SVR compared with patients with normal risk (P < 0.05), and that remained until deflation, but no interval changes in MAP and heart rate. The CI, MAP and heart rate decreased and SVR increased significantly in patients with cardiac risk compared with patients with normal risk before incision (P < 0.05). No complications occurred. The results indicate that pneumoperitoneum and a reversed Trendelenburg are associated with significant but relatively benign hemodynamic changes. CONCLUSIONS: Anesthesia for laparoscopic cholecystectomy in elderly patients with increased cardiac risk should be performed with an adequate hemodynamic monitoring.

The hemodynamic effects of a reversed Trendelenburg in elderly patients with increased cardiac risk during laparoscopic cholecystectomy / 대한마취과학회지

BACKGROUND: We studied the hemodynamic changes induced by pneumoperitoneum and a reversed Trendelenburg in elderly patients with increased cardiac risk (ASA class III; n = 30; age 70.8 +/- 4.9 years, mean +/- SD) and compared the results with elderly patients at normal risk (ASA class II; n = 30; age 69.2 +/- 4.1 years) during laparoscopic cholecystectomy. METHODS: The transesophageal Doppler monitor was performed after induction of general anesthesia (pre-incision), after onset of pneumoperitoneum (insufflation), after head-up (20degrees) and a left lateral tilt (15degrees) (reversed Trendelenburg) and after deflation and horizontal position (desufflation). Mean arterial pressure (MAP), heart rate, cardiac index (CI) and systemic vascular resistance (SVR) were measured, respectively. RESULTS: Induction of pneumoperitoneum and head-up tilt in patients with cardiac risk resulted significantly in a decrease in CI and an increase in SVR compared with patients with normal risk (P < 0.05), and that remained until deflation, but no interval changes in MAP and heart rate. The CI, MAP and heart rate decreased and SVR increased significantly in patients with cardiac risk compared with patients with normal risk before incision (P < 0.05). No complications occurred. The results indicate that pneumoperitoneum and a reversed Trendelenburg are associated with significant but relatively benign hemodynamic changes. CONCLUSIONS: Anesthesia for laparoscopic cholecystectomy in elderly patients with increased cardiac risk should be performed with an adequate hemodynamic monitoring.

Comparison with hemodynamic changes of laparoscopic surgery by body position

BACKGROUND: The authors evaluated the hemodynamic effects of body position measured by esophageal Doppler monitor (EDM) during laparoscopic cholecystectomy or gynecologic laparoscopic surgery. METHODS: Fifty patients scheduled to undergo laparoscopic cholecystectomy (Group C) or gynecologic laparoscopic surgery (Group G), were divided into two groups. Pneumoperitoneum was instituted by CO2 gas and the intraperitoneal pressure was kept under 12 mmHg. Hemodynamic parameters at critical points were measured by the use of EDM: before skin incision (T1), 5, 10 and 15 min after changing position (T2, T3 and T4), and 5 min after CO2 exsufflation (T5). RESULTS: MAP (mean arterial pressure) was significantly higher in Group G when compared with Group C 10 min after changing position (T3) (P< 0.05). CO (cardiac output) was significantly decreased in Group G when compared with Group C 10 min after changing position (T3) (P< 0.05). And there were not significant differences in HR (heart rate) between two groups. PV (peak velocity) was significantly decreased in Group G when compared with Group C 10 min after changing position (T3) (P< 0.05). And there were not significant differences in FTc (corrected flow time) between two groups. But FTc in Group C was restored after CO2 exsufflation, FTc in Group G was not restored after CO2 exsufflation. CONCLUSIONS: Changing position in the gynecologic laparoscopic surgery group can elevate MAP and decrease CO. Therefore, careful caution is required in patients with cardiovascular disease who are undergoing gynecologic laparoscopic surgery.

Hemodynamic Effects of Nicardipine Measured by Esophageal Doppler Monitor during Gynecologic Laparoscopic Surgery

BACKGROUND: The authors performed this study to investigate the hemodynamic effect of nicardipine using an esophageal Doppler monitor (EDM) during gynecologic laparoscopic surgery. METHODS: Forty patients scheduled to undergo gynecologic laparoscopic surgery, were divided into two groups; the control group (Group C) and the nicardipine group (Group N). Pneumoperitoneum was initiated using CO2 gas and the intraperitoneal pressure was kept under 12 mmHg. Hemodynamic parameters at critical points were measured using EDM, i.e., before skin incision (T1), 5, 10 and 15 min after the initiation of pneumoperitoneum (T2, T3 and T4), and 5 min after deflation (T5). RESULTS: Mean arterial pressure (MAP) was significantly lower in Group N patients than in Group C patients at 5 and 10 min after the initiation of pneumoperitoneum (T2 and T3) (P < 0.05). No significant heart rate (HR) differences were observed between the two study groups. Cardiac output (CO), peak velocity (PV) and corrected flow time (FTC) were significantly higher in Group N at 10 min after the initiation of pneumoperitoneum (T3) (all P < 0.05). CONCLUSIONS: The nicardipine continuous infusion at 0.5?2.0microg/ kg/min is effective at attenuating hemodynamic changes after pneumoperitoneum during gynecologic laparoscopic surgery.

Utility of Esophageal Doppler and the Hemodynamic Effect of Nicardipine during a Laparoscopic Cholecystectomy / 대한마취과학회지

BACKGROUND: We performed this study to investigate the hemodynamic effect of nicardipine using an esophageal Doppler monitor (EDM) during a laparoscopic cholecystectomy. METHODS: Forty patients scheduled to undergo a laparoscopic cholecystectomy, were divided into two groups; the control group (Group C) and the nicardipine group (Group N). Pneumoperitoneum was initiated by CO2 gas and the intraperitoneal pressure was kept under 12 mmHg. Hemodynamic parameters at critical points were measured by the use of EDM: before skin incision (T1), 5, 10 and 15 min after the initiation of pneumoperitoneum (T2, T3 and T4), and 5 min after deflation (T5). RESULTS: The mean arterial pressure (MAP) was significantly lower in the Group N patients when compared to the Group C patients 5, 10 and 15 min after the initiation of pneumoperitoneum (T2, T3 and T4), and 5 min after deflation (T5)(P < 0.05). There was no significant differences in heart rate (HR) between patients in the two groups. The cardiac output (CO) was significantly increased in the Group N patients when compared to the Group C patients 5 min after the initiation of pneumoperitoneum (T2)(P < 0.05). The peak velocity (PV) was significantly increased in the Group N patients when compared to the Group C patients 5 and 10 min after the initiation of pneumoperitoneum (T2 and T3)(P < 0.05). The corrected flow time (FTC) was significantly increased in the Group N patients when compared to the Group C patients 5 min after the initiation of pneumoperitoneum (T2)(P < 0.05). CONCLUSIONS: We conclude that nicardipine continuous infusion with 0.5-2.0microgram/kg/min is effective in attenuating the hemodynamic change after pneumoperitoneum during a laparoscopic cholecystectomy.

Comparison of Hemodynamic Data obtained from a Pulmonary Artery Catheter vs. Esophageal Doppler during Liver Transplantation / 대한마취과학회지

BACKGROUND: The measurement of cardiac output is an essential part of anesthetic practice in patients undergoing liver transplantation. A thermodilution technique, using a pulmonary artery catheter is currently accepted as the gold standard in clinical practise. However, its use is associated with several limitations. METHODS: An esophageal doppler monitor was compared with the thermodilution technique in 22 patients undergoing split graft transplantation from a living donor. Six measurement were taken during liver transplantation, 1) control, 2) dissection phase, 3) anhepatic phase, 4) reperfusion phase, 5) after hepatic artery anastomosis, and 6) end of surgery. RESULTS: Significant difference were observed between the two measurement at all times studied with a strong correlation, except at the end of surgery (r > 0.4). CONCLUSIONS: The use of esophageal doppler monitor results in cardiac output measurements which are considerably different from those obtained using thermodilution, but a strong correlation exists between two methods. Thus the use of esohageal monitoring can be recommended in patients undergoing liver transplantation for trend monitoring.

Hemodynamic Changes Measured by Esophageal Doppler Monitor during Laparoscopic Cholecystectomy and Gynecologic Pelviscopy / 대한마취과학회지

BACKGROUND: Laparoscopic cholecystectomy and gynecologic pelviscopy need to induce pneumoperitoneum to allow visualization of the operative field, but the former requires a head-up position whereas the latter needs a Lithotomy-Trendelenburg position. The authors observed hemodynamic changes using an esophageal doppler monitor in both cases. METHODS: Eight females planned for laparoscopic cholecystectomy were assigned to Group 1 and 10 females for gynecologic pelviscopy were assigned to Group 2. Thiopental (5 mg/kg) and vecuronium (0.1 mg/kg) were used to induce general anesthesia. 50% O2-N2O and 1.5 vol.% isoflurane were used to maintain anesthesia. Mechanical ventilation was used with a tidal volume of 10 ml/kg and a respiratory rate of 12 breaths per minute. Mean arterial pressure, heart rate, end-tidal CO2 and peak airway pressure were measured and cardiac output, corrected flow time, and peak velocity were monitored using an esophageal doppler monitor in each group after inducing anesthesia, CO2 inflation, position change, and CO2 deflation. RESULTS: Mean arterial pressure increased in each group while changing position. No significant changes in the heart rate were observed in each group. End-tidal CO2 increased in each group after changing position, and remained elevated even with position reversal and deflation. Peak airway pressure was elevated in each group after CO2 inflation and increased more so with changing posture in group 2 (post inflation: 18.5 +/- 1.4 cmH2O, after position change: 21.4 +/- 2.0 cmH2O). Cardiac output and cardiac index were reduced after the induction of pneumoperitoneum in each group, and reduced more on changing posture in group 2 (CO: 5.9 +/- 2.0 L/min vs. 4.4 +/- 1.5 L/min, CI: 3.7 +/- 1.4 L/min/m2 vs. 2.7 +/- 1.1 L/min/m2). Stroke volume also reduced after changing posture in each group. Corrected flow time was not changed, but peak velocity decreased after CO2 inflation in each group (group 1: 97.4 +/- 30.0 cm/s vs. 78.9 +/- 27.3 cm/s, group 2: 111.9 +/- 14.1 cm/s vs. 88.3 +/- 12.6 cm/s). CONCLUSIONS: The Lithotomy-Trendelenburg position can augment the hemodynamic changes resulting from pneumoperitoneum. Therefore, additional caution is required in patients with cardiovascular disease who are undergoing gynecologic pelviscopy.