Validation of esophageal Doppler for noninvasive hemodynamic monitoring under pneumoperitoneum

Predicting fluid responsiveness using esophagus Doppler monitoring and pulse oximetry derived pleth variability index; retrospective analysis of a hemodynamic study

BACKGROUND

Fluid therapy during major surgery can be managed by providing repeated bolus infusions until stroke volume no longer increases by ≥ 10%. However, the final bolus in an optimization round increases stroke volume by < 10% and is not necessary. We studied how different cut-off values for the hemodynamic indications given by esophagus Doppler monitoring, as well as augmentation by pulse oximetry, are associated with a higher or smaller chance that stroke volume increases by ≥ 10% (fluid responsiveness) before fluid is infused.

METHODS

An esophagus Doppler and a pulse oximeter that displayed the pleth variability index were used to monitor the effects of a bolus infusion in 108 patients undergoing goal-directed fluid therapy during major open abdominal surgery.

RESULTS

The analyzed data set comprised 266 bolus infusions. The overall incidence of fluid responsiveness was 44%, but this varied greatly depending on pre-infusion hemodynamics. The likelihood of being fluid-responsive was 30%-38% in the presence of stroke volume > 80 mL, corrected flow time > 360 ms, or pleth variability index < 10%. The likelihood was 21% if stroke volume had decreased by <8% since the previous optimization, which decreased to 0% if combined with stroke volume > 100 mL. By contrast, the likelihood of fluid responsiveness increased to 50%-55% when stroke volume ≤ 50 mL, corrected flow time ≤ 360 ms, or pleth variability index ≥ 10. A decrease in stroke volume by > 8% since the previous optimization was followed by a 58% likelihood of fluid responsiveness that, in combination with any of the other hemodynamic variables, increased to 66%-76%.

CONCLUSIONS

Single or combined hemodynamic variables provided by esophagus Doppler monitoring and pulse oximetry derived pleth variability index could help clinicians avoid unnecessary fluid bolus infusions.

The determination of real fluid requirements in laparoscopic resection of pheochromocytoma using minimally invasive hemodynamic monitoring: a prospectively designed trial

Background

Hemodynamic instability is frequently observed during adrenalectomy for pheochromocytoma (PCC). Guidelines recommend liberal preoperative volume administration. However, it is unclear whether fluid deficiency or vasoplegia causes shifting hemodynamics and whether minimally invasive hemodynamic monitoring with esophageal Doppler (EDM) can help visualize intraoperative changes avoiding volume overload and complications.

Methods

Ten patients with biochemically verified PCC and five patients with hormonally inactive adrenal tumors (HIAT; control group) were treated following a strict protocol. During laparoscopic adrenalectomy, goal-directed fluid therapy was performed using EDM. Hemodynamic and biochemical data were documented. The primary outcome variables were fluid requirement and hemodynamic parameters.

Results

Applying EDM, total intraoperative fluid administration was slightly higher in PCC patients than in patients with HIAT (2100 ± 516 vs. 1550 ± 622 ml, p = 0.097; 12.9 ± 4.8 vs. 8.3 ± 0.7 ml kg⁻¹ h⁻¹, p = 0.014). Hemodynamics varied considerably within the PCC group and was associated with type and level of secreted catecholamines. Arterial blood pressure and systemic vascular resistance index reached their minimum in the 10-min period after resection of PCC. Without liberal fluid administration, an increase in cardiac index was observed in both groups comparing baseline measurements to end of surgery. This increase was statistically significant only in PCC patients (PCC: 2.31 vs. 3.15 l min⁻¹ m⁻², p = 0.005; HIAT: 2.08 vs. 2.56 l min⁻¹ m⁻², p = 0.225).

Conclusions

As vasoplegia, but not hypovolemia, was documented after tumor resection, there is no evidence that PCC patients profit from liberal fluid administration during laparoscopic adrenalectomy. To avoid volume overload, noninvasive techniques such as EDM should be routinely used to visualize the variable intraoperative course.

Trial registration: ClinicalTrials.gov, Identifier: NCT01425710.

Perioperative Outcomes of Robotic-Assisted Hysterectomy Compared With Open Hysterectomy

BACKGROUND

Increasing numbers of robotic hysterectomies (RH) are being performed. To provide ventilation (with pneumoperitoneum and steep Trendelenburg position) for these procedures, utilization of lung protective strategies with limiting airway pressures and tidal volumes is difficult. Little is known about the effects of intraoperative mechanical ventilation and high peak airway pressures on perioperative complications. We performed a retrospective review to determine whether patients undergoing RH had increased pulmonary complications compared to total abdominal hysterectomy (TAH).

METHODS

We performed a single center retrospective review comparing the intraoperative, anesthetic, and immediate and 30-day postoperative course of patients undergoing RH to TAH, including intraoperative ventilatory parameters and respiratory complications. Patients undergoing TAH (201) from 2004 to 2006 were compared to RH (251) from 2009 to 2012. It was our hypothesis that patients undergoing RH would have increased incidence of postoperative pulmonary complications. A secondary hypothesis was that morbid obesity predicts pulmonary complications in patients undergoing RH. Complications were compared between groups using Fisher's exact test. To account for potential confounders, the primary analysis was performed for a subgroup of patients matched on the propensity for RH.

RESULTS

A total of 351 RH and 201 TAH procedures are included. Higher inspiratory pressures were required in ventilation of the RH group (median [25th, 75th] 31 [26, 36] cm H2O) than the TAH group (23 [19, 27] cm H2O) (P < .001) at 30 minutes after incision. Peak inspiratory pressures at 30 minutes after incision for RH increased according to increasing body mass index group (P < .001). There were 163 RH and 163 TAH procedures included in the propensity matched analysis. From this analysis, there were no significant differences in cardiopulmonary complications between RH and TAH (0.6% vs 1.2%; odds ratio = 2.0, 95% confidence interval = 0.2-2.4; P = 1.00). Surgical site infection was significantly lower in the RH compared to TAH group (0.6% vs 8.6%; P < .001). Hospital length of stay was longer for those who underwent TAH versus RH (median [25th, 75th] 2 [2, 3] vs 1 [0, 2] days; P < .001).

CONCLUSIONS

There was no significant difference in perioperative complications in obese and morbidly obese women compared to nonobese undergoing RH. Patients undergoing RH had shorter hospital stays, fewer infectious complications, and no increase in overall complications compared to TAH. Higher ventilatory airway pressures (RH versus TAH and obese versus nonobese) did not result in an increase in cardiopulmonary or overall complications. We believe that peritoneal insufflation attenuates the effect of high airway pressures by raising intrapleural pressure and reducing the gradient across terminal bronchioles and alveoli. Thus, we propose that lung protective strategies for patients undergoing RH account for the markedly elevated intraperitoneal and intrapleural pressures, whereas transpulmonary airway pressures remain static. This reduced transpulmonary gradient attenuates the strain on lung tissue that would otherwise be imposed by ventilation at high pressures.

[Anesthetic management of robot-assisted radical prostatectomy]

The authors have an experience in performing of 700 radical prostatectomies by using of daVinci-robot. The main factors determining parameters of operation and anesthesia are presented in the article. The authors give recommendations for optimization of anesthetic management. The main features of patient preparation for robot-assisted radical prostatectomy, parameters of anesthesia and postoperative management of patients are presented in the article.

Targeting individual hemodynamics to maintain renal perfusion during pneumoperitoneum in a porcine model

BACKGROUND

Although aggressive fluid hydration prevents a decrease in renal cortical perfusion (RCP) during laparoscopic donor nephrectomy, excess fluid is deleterious. We assessed whether goal-directed fluid administration, based on hemodynamic measures, would maintain RCP during pneumoperitoneum with less fluid loading.

METHODS

In a pilot study of 7 pigs, goal-directed fluid administration was guided by monitoring of stroke volume (SV) by esophageal Doppler measurement. During 15 mmHg CO(2) pneumoperitoneum, a bolus of 5 mL/kg 0.9% NaCl was given when SV decreased to 90% of baseline. Next, 18 pigs were randomized into 3 groups: low fluid (5 mL/kg per hour), high fluid (25 mL/kg per hour) and goal directed. Urine output, heart rate, mean arterial pressure, cardiac output, SV, and RCP were recorded every 15 minutes.

RESULTS

Pilot data revealed mean RCP (mL/min per 100 g) was maintained (40 vs 39) during pneumoperitoneum using goal-directed therapy. In the randomized study, RCP was decreased in the low fluid group (43 vs 29; P= .02), but maintained in the high (46 vs 40) and goal-directed (42 vs 39) groups. Mean fluid administered in the goal-directed group during pneumoperitoneum was 10 mL/kg and only 3 of 6 of pigs required boluses. Urine output was decreased in all 3 groups.

CONCLUSION

A goal-directed strategy during pneumoperitoneum allows for tailored fluid administration and maintains RCP with lower volumes of intravenous fluid.