Pulse Contour Analysis and Transesophageal Echocardiography: A Comparison of Measurements of Cardiac Output During Laparoscopic Colon Surgery

Effect of different targets of goal-directed fluid therapy on intraoperative hypotension and fluid infusion in robot-assisted laparoscopic gynecological surgery: a randomized non-inferiority trial

Carotid corrected flow time (FTc) and tidal volume challenge pulse pressure variation (VtPPV) are useful clinical parameters for assessing volume status and fluid responsiveness in robot-assisted surgery, but their usefulness as goal-directed fluid therapy (GDFT) targets is unclear. We investigated whether FTc or VtPPV as targets are inferior to PPV in GDFT. This single-center, prospective, randomized, non-inferiority study included 133 women undergoing robot-assisted laparoscopic gynecological surgery in the modified head-down lithotomy position. Patients were equally divided into three groups, and the GDFT protocol was guided by FTc, VtPPV, or PPV during surgery. Primary outcomes were non-inferiority of the time-weighted average of hypotension, intraoperative fluid volume, and urine output. Secondary outcomes were optic nerve sheath diameter (ONSD) pre- and post-operatively and creatinine and blood urea nitrogen preoperatively and on day 1 post-operatively. No significant differences were observed in intraoperative hypotension index, infusion and urine volumes, and ONSD post-operatively between the FTc and VtPPV groups and the PPV group. No differences in serum creatinine and urea nitrogen levels were identified between the FTc and VtPPV groups preoperatively, but on day 1 post-operatively, the urea nitrogen level in the FTc group was higher than that in the PPV group (4.09 ± 1.28 vs. 3.0 ± 1.1 mmol/L, 1.08 [0.59, 1.58], p < 0.0001), and the difference from the preoperative value was smaller than that in the PPV group (- 2 [- 2.97, 1.43] vs. - 1.34 [- 1.9, - 0.67], p = 0.004). FTc- or VtPPV-guided protocols are not inferior to that of PPV in GDFT during robot-assisted laparoscopic surgery in the modified head-down lithotomy position.Trial registration: Chinese Clinical Trial Registry (ChiCTR2200064419).

Intraoperative cardiac function assessment by transesophageal echocardiography versus FloTrac/Vigileo™ system during pectus excavatum surgical repair

BACKGROUND

Pectus excavatum (PE), a congenital deformity of the chest wall, can lead to cardiac compression and related symptoms. PE surgical repair can improve cardiac function. Intraoperative transesophageal echocardiography (TEE) has been successfully employed to assess intraoperative hemodynamic variations in patients undergoing PE repair. FloTrac/Vigileo™ system (Edwards Life-sciences Irvine, CA) (FT/V) is a minimally invasive cardiac output monitoring system. This retrospective study aimed to assess hemodynamic changes in surgical repair of PE using FT/V and concordance with parameters measured by TEE.

RESULTS

N=19 patients submitted to PE repair via Ravitch or Nuss technique were enrolled. Intraoperative cardiac assessments simultaneously obtained via TEE and FT/V system were investigated. The agreement between TEE-derived cardiac output (CO-TEE) and FT/V system parameter (COAP) was evaluated. The relationship between COTEE and COAP was analyzed for all data using linear regression analysis. A significant correlation between COAP and COTEE values (R = 0.65, p < 0.001) was found. Bland-Altman analysis of COAP and COTEE showed a bias of 0.13 L/min and a limit of agreement of - 2.33 to 2.58 L/min, with a percentage error of 48%. Intraoperative measurements by TEE and FT/V both showed a significant increase in CO after surgical correction of PE (p < 0.005).

CONCLUSIONS

FT/V system compared to TEE in hemodynamic monitoring during PE surgery yielded clinically unacceptable results due to a high percentage error. After surgical correction of PE, CO, measured by TEE and FT/V, significantly improved.

Utility of the FloTrac™ Sensor for Anesthetic Management of Laparoscopic Surgery in a Patient After Pneumonectomy: A Case Report and Literature Review

BACKGROUND Pneumonectomy is associated with various anatomical changes and potential complications involving the respiratory and cardiovascular systems. How laparoscopic surgery affects cardiorespiratory status in postpneumonectomy patients is yet to be ascertained. Here, we describe the use of the FloTrac™ sensor for the anesthetic management of laparoscopic adrenalectomy in a postpneumonectomy patient. CASE REPORT A 35-year-old woman underwent an extended hysterectomy and right pneumonectomy for retroperitoneal angiosarcoma and lung metastases, respectively. The metastasis was found in her left adrenal gland; therefore, laparoscopic adrenalectomy was scheduled. Spirometry demonstrated the following: forced vital capacity (FVC), 1.90 L (55.6% of predicted value); vital capacity, 53.6%; forced expiratory volume (FEV₁), 1.38 L (47.3% of predicted value); and FEV₁/FVC, 72.4%. The heart and mediastinal structures had shifted into the right hemithorax. Hugh-Jones classification was grade 2. The induction of general anesthesia was planned. The patient was orotracheally intubated and managed with the pressure control ventilation-volume guaranteed mode of ventilation, targeting an expired tidal volume of 6-7 ml/kg, without using PEEP. We evaluated cardiac output (CO), cardiac index (CI), stroke volume (SV), and stroke volume variation (SVV) using a FloTrac™ sensor. After the establishment of pneumoperitoneum, SVV increased. CO and SV decreased slightly; however, the patient's hemodynamic status was stable. After surgery, we extubated the patient in the operating room; she demonstrated good progress and was discharged home on postoperative day 5. CONCLUSIONS We found changes in the values of SVV after pneumoperitoneum in a postpneumonectomy patient. The FloTrac™ sensor may be a minimally invasive and promising monitor for detecting hemodynamic changes associated with laparoscopic surgery in postpneumonectomy patients.

The effects of laparoscopic urologic surgery on cardiac functions: A pulse wave velocity study

OBJECTIVE

The aim of this study is to evaluate the effects of laparoscopic urologic surgery on cardiac functions by the parameter pulse wave velocity (PWV), a noninvasive method.

MATERIAL AND METHODS

Between July 2012 and February 2013, a total of 47 patients were included in this prospective controlled study. Patients who have been scheduled for laparoscopic surgery (LS) (n=30) and open surgery (n=17) were enrolled in the study. Preoperative, perioperative, and postoperative cardiovascular parameters were measured by a PWV instrument, and the results were compared between laparoscopic (L) group and open (C) group.

RESULTS

In the L group, compared to preoperative values, perioperative systolic arterial pressure, diastolic arterial pressure, and mean arterial pressure increased considerably, by 2.6%, 7.9%, and 4.7%, respectively. This was in contrary to reductions in these parameters by 9.5%, 5.7%, and 10%, respectively, in the C group. For the L group, cardiac output (CO) and cardiac index (CI) were increased in the perioperative period and decreased in the postoperative period. For the C group, there were no changes in measurements of perioperative and postoperative CO and CI. However, these changes in CO and CI were not significantly different between the L and C groups. Postoperative large artery elasticity index decreased in both groups. However, these changes did not represent significant difference between groups.

CONCLUSION

Compared to open surgery, LS may cause increases in perioperative blood pressures. In addition, increased blood pressures may last even on the first postoperative day. These effects may be more important for patients with high cardiovascular risk.

Reliability of Cardiac Output Measurements Using LiDCOrapid and Calibration by Transesophageal Echocardiography With the Continuous Pulmonary Artery Thermodilution Method in Patients Undergoing Aortic Valve Replacement for Aortic Stenosis

OBJECTIVE

This study investigated the accuracy of arterial waveform analysis estimations of cardiac output (CO_AW) and the efficacy of calibrations involving transesophageal echocardiography with continuous cardiac output values obtained using a pulmonary artery catheter.

DESIGN

Prospective cohort study.

SETTING

University hospital operating room.

PARTICIPANTS

Twelve patients undergoing aortic valve replacement for aortic stenosis.

INTERVENTIONS

A pulmonary artery catheter was placed in each patient, and continuous cardiac output was determined using thermodilution principles. LiDCOrapid and transesophageal echocardiography were used to measure CO_AW and to perform the calibration, respectively.

MEASUREMENTS AND MAIN RESULTS

Simultaneous recording of continuous cardiac output and CO_AW values were performed every 20 minutes, after inducing anesthesia. CO_AW was calibrated using transesophageal echocardiography (CO_AW-cal) before and after initiating cardiopulmonary bypass (CPB); the CO_AW and CO_AW-cal were recorded concurrently using a LiDCOrapid monitor. For the pre-CPB dataset (34 data pairs), the mean bias and percentage error were, respectively, 0.10 L/min and 34% for CO_AW versus continuous cardiac output and -0.098 L/min and 27% for CO_AW-cal versus continuous cardiac output. Similarly, for the post-CPB (45 data pairs), the mean bias and percentage error were, respectively, 0.75 L/min and 34% for CO_AW and 0.059 L/min and 26% for CO_AW-cal. A 4-quadrant plot demonstrated an acceptable pre-CPB concordance rate of 93.3% for CO_AW and 93.8% for CO_AW-cal.

CONCLUSION

CO_AW measurements, using LiDCOrapid, have acceptable trending ability pre-CPB. The determination of cardiac output variations, using transesophageal echocardiography, is useful for managing patients undergoing aortic valve replacement for aortic stenosis.

Comparison of pulmonary artery catheter, echocardiography, and arterial waveform analysis monitoring in predicting the hemodynamic state during and after cardiac surgery

Objective:

The aim of this trial was to determine whether Flotrac Vigileo™ (FV™) provides a reliable representation of the hemodynamic state of a cardiac surgical patient population when compared to pulmonary artery catheter (PAC) and echocardiography in the peril-operative period.

Design:

This was a prospective observational trial comparing perioperative hemodynamic states using transesophageal echocardiography (TEE), transthoracic echocardiography (TTE), FV™ and PAC during and post cardiothoracic surgery.

Setting:

Tertiary regional hospital Intensive Care Unit (ICU).

Participants:

50 consecutive adult cardiothoracic patients with written consent provided.

Intervention:

Comparison of the perioperative hemodynamic states using echocardiography, FV™ and PAC was performed. Evaluation of the hemodynamic state (HDS) was performed using TEE, TTE, PAC and FV™ during and after cardiac surgery. Data were compared between the three hemodynamic assessment modalities.

Main Outcome Measure:

Predicted hemodynamic state.

Results:

FV™ and PAC were shown to correlate poorly with TEE/TTE assessment of the hemodynamic state. Both PAC and FV™ showed significant discordance with echocardiographic assessment of the hemodynamic state.

Conclusions:

In this trial, FV™ and PAC were shown to agree poorly with TTE/TEE assessment of the HDS in an adult cardiothoracic population. Agreement between the FV™ and PAC was also poor. Caution is recommended in interpreting isolated hemodynamic monitoring data. All hemodynamic monitoring devices have inherent sources of error. Caution is advised in interpreting any single device or measurement as a gold standard. We suggest that hemodynamic measuring devices such as FV™/PAC may act as triggers for a global hemodynamic assessment including consideration of TTE/TEE.

Systematic review of uncalibrated arterial pressure waveform analysis to determine cardiac output and stroke volume variation

The FloTrac/Vigileo™, introduced in 2005, uses arterial pressure waveform analysis to calculate cardiac output (CO) and stroke volume variation (SVV) without external calibration. The aim of this systematic review is to evaluate the performance of the system. Sixty-five full manuscripts on validation of CO measurements in humans, published in English, were retrieved; these included 2234 patients and 44,592 observations.

RESULTS

have been analysed according to underlying patient conditions, that is, general critical illness and surgery as normodynamic conditions, cardiac and (post)cardiac surgery as hypodynamic conditions, and liver surgery and sepsis as hyperdynamic conditions, and subsequently released software versions. Eight studies compared SVV with other dynamic indices. CO, bias, precision, %error, correlation, and concordance differed among underlying conditions, subsequent software versions, and their interactions, suggesting increasing accuracy and precision, particularly in hypo- and normodynamic conditions. The bias and the trending capacity remain dependent on (changes in) vascular tone with most recent software. The SVV only moderately agreed with other dynamic indices, although it was helpful in predicting fluid responsiveness in 85% of studies addressing this. Since its introduction, the performance of uncalibrated FloTrac/Vigileo™ has improved particularly in hypo- and normodynamic conditions. A %error at or below 30% with most recent software allows sufficiently accurate and precise CO measurements and trending for routine clinical use in normo- and hypodynamic conditions, in the absence of large changes in vascular tone. The SVV may usefully supplement these measurements.

Goal-directed therapy in intraoperative fluid and hemodynamic management

Intraoperative fluid management is pivotal to the outcome and success of surgery, especially in high-risk procedures. Empirical formula and invasive static monitoring have been traditionally used to guide intraoperative fluid management and assess volume status. With the awareness of the potential complications of invasive procedures and the poor reliability of these methods as indicators of volume status, we present a case scenario of a patient who underwent major abdominal surgery as an example to discuss how the use of minimally invasive dynamic monitoring may guide intraoperative fluid therapy.

A comparison of pulse contour wave analysis and ultrasonic cardiac output monitoring in the critically ill

Cardiac output (CO) is a key determinant of major organ blood flow and solute delivery to drug eliminating organs. As such, CO assessment is a key covariate in understanding altered drug handling in the critically ill. Newer minimally-invasive devices are providing unique platforms for such an application, although comparison data are currently lacking. In this study we evaluated the Vigileo (Edwards Lifesciences, Irvine, CA, USA) and USCOM (USCOM Ltd, Sydney, NSW) devices in 62 critically ill patients requiring antibacterial therapy. The mean COVigileo and COUSCOM for the first paired measurements were 8.20±2.65 l/minute and 6.84±2.57 l/minute respectively (P <0.001). A significant correlation was evident in all patients (r=0.537, P <0.001) although the recorded bias was large (1.36±2.51 l/minute, limits of agreement -3.6 to±6.3 l/minute). The overall percentage error was 65%. There was an improved correlation in those admitted with sepsis (r=0.639, P <0.001), compared to trauma (r=0.373, P=0.066), although bias, precision and percentage error were similar in both subgroups. In 54 patients a second paired assessment was obtained at three hours. A weak, although significant correlation (r=0.377, P=0.005) was observed suggesting that gross trends over time were similar. In conclusion, our findings demonstrate poor agreement between these techniques suggesting that these devices are not simply interchangeable when assessing CO in a research or clinical setting.

Drug-administration sequence of target-controlled propofol and remifentanil influences the onset of rocuronium. A double-blind, randomized trial

BACKGROUND

Remifentanil is known to cause bradycardia and hypotension, as well as the decreases of cardiac output (CO). We hypothesized that hemodynamic suppression by remifentanil would affect the onset time of rocuronium. This study investigated whether the onset of rocuronium was influenced by the drug-administration sequence during induction of anesthesia with target-controlled infusion of propofol and remifentanil.

METHODS

Healthy adult patients (n = 126) undergoing elective surgery under general anesthesia were randomized into two groups according to drug-administration sequence. In Remi-Pro-Rocu group (n = 62), remifentanil was infused first, followed by propofol. Then, rocuronium was administered lastly. In Pro-Rocu-Remi group (n = 64), propofol, rocuronium, and remifentanil were given in that order. As a primary outcome, the onset time of rocuronium was measured. Mean arterial pressure (MAP), heart rate (HR), CO, and stroke volume were recorded before anesthesia (T1), at injection of rocuronium (T2), immediately before and after intubation (T3 and T4).

RESULTS

In Remi-Pro-Roc group, the onset of rocuronium was delayed significantly compared with Pro-Rocu-Remi group [median (interquartile range); 130 (105-150) vs. 90 (71-100) s, P < 0.001]. At the time of rocuronium injection (T2), MAP, HR, and CO were significantly lower in Remi-Pro-Rocu group than Pro-Rocu-Remi group (P < 0.001).

CONCLUSION

The onset time of rocuronium is prolonged significantly by early administration of remifentanil during target-controlled infusion of propofol and remifentanil, and it may be due to the decreased CO caused by remifentanil.

Cardiac output assessed by invasive and minimally invasive techniques

Cardiac output (CO) measurement has long been considered essential to the assessment and guidance of therapeutic decisions in critically ill patients and for patients undergoing certain high-risk surgeries. Despite controversies, complications and inherent errors in measurement, pulmonary artery catheter (PAC) continuous and intermittent bolus techniques of CO measurement continue to be the gold standard. Newer techniques provide less invasive alternatives; however, currently available monitors are unable to provide central circulation pressures or true mixed venous saturations. Esophageal Doppler and pulse contour monitors can predict fluid responsiveness and have been shown to decrease postoperative morbidity. Many minimally invasive techniques continue to suffer from decreased accuracy and reliability under periods of hemodynamic instability, and so few have reached the level of interchangeability with the PAC.

Comparison of Cardiac Output Measurements in Critically Ill Patients: Flotrac/Vigileo Vs Transthoracic Doppler Echocardiography

Measurement of cardiac output is an integral part of patient management in the intensive care unit. FloTrac/Vigileo is a continuous cardiac output monitoring device that does not need re-calibration. However, its reliability has been questioned in some studies, especially involving surgical patients. In this study, we evaluated the comparability of FloTrac/Vigileo and transthoracic Doppler echocardiography in 53 critically ill patients requiring continuous cardiac output monitoring. Most of these patients had septic or cardiogenic shock. Cardiac output was measured by both FloTrac/Vigileo and transthoracic Doppler echocardiography. The bias and precision (mean and SD) between the two devices was 0.35±1.35 l/minute. The limits of agreement were -2.3 to 3.0 l/minute (%error=49.3%). When patients with irregular heart rhythms and aortic stenosis were excluded, the bias and precision was 0.02±0.80 l/minute (n=42). The limits of agreement were -1.55 to 1.59 l/minute (%error=29.5%). Patient demographics (body surface area, gender and age) did not affect the bias, but there was a mild tendency for FloTrac/Vigileo to register a higher cardiac output at high heart rates. Changes in cardiac output for two consecutive days correlated well between the two methods (r=0.86; P <0.001). In summary, with the exceptions of patients with irregular heart rhythms and significant aortic stenosis, FloTrac/Vigileo is clinically comparable to transthoracic Doppler echocardiography in cardiac output measurements in critically ill patients.

Transthoracic focused rapid echocardiographic examination: real-time evaluation of fluid status in critically ill trauma patients

BACKGROUND

A transthoracic focused rapid echocardiographic evaluation (FREE) was developed to answer specific questions about treatment direction regarding the use of fluid versus ionotropes in trauma patients. Our objective was to evaluate the clinical utility of the information obtained by this diagnostic test.

METHODS

The FREE was performed by an ultrasonographer or an intensivist and interpreted by a surgical intensivist using a full service portable echo machine (Vivid i; GE Healthcare). The clinical team ordering the examination was surveyed before and after the test was performed.

RESULTS

During a 9-month study period, the FREE was performed in 53 patients admitted to our trauma critical care units. In 80% of patients, an estimated ejection fraction was obtained. Moderate and severe left ventricular dysfunction was diagnosed in 56% of patients, and right heart dysfunction was found in 25% of the patients. Inferior vena cava (IVC) diameter and IVC respiratory variation was visualized in 80% of patients. In 87% (46 of 53), the FREE was able to answer the clinical question asked by the primary team. Strikingly, in 54% of patients, the plan of care was modified as a result of the FREE examination.

CONCLUSIONS

IVC diameter and IVC respiratory variation was able to be obtained in the majority of cases, giving an estimate of fluid status. Estimation of ejection fraction was useful in guiding the treatment plan regarding the requirement of fluid boluses versus ionotropic support. We conclude that the FREE can provide meaningful data in difficult to image critically ill trauma patients.