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.

Agreement of Bioreactance Cardiac Output Monitoring With Thermodilution in Healthy Standing Horses

Bioreactance is the continuous analysis of transthoracic voltage variation in response to an applied high frequency transthoracic current and was recently introduced for non-invasive cardiac output measurement (NICOM). We evaluated NICOM compared to thermodilution (TD) in adult horses. Six healthy horses were used for this prospective, blinded, experimental study. Cardiac output (CO) measurements were performed simultaneously using TD and the bioreactance method. Different cardiac output scenarios were established using xylazine (0.5 mg/kg IV) and dobutamine (1.5–3 mcg/kg/min). Statistical analysis was performed by calculating the concordance rate, performing a regression analysis, Pearson correlation, and Bland Altman. The TD-based CO and NICOM values were highly correlated for low, normal and high CO values with an overall correlation coefficient. A 4-quadrant plot showed an 89% rate of concordance. The linear regression calculated a relationship between NICOM and TDCO of Y = 0.4874 · X + 0.5936. For the corrected Bland Altman agreement, the mean bias and lower/upper limits of agreement were −0.26 and −3.88 to 3.41 L/min, respectively. Compared to TD, bioreactance- based NICOM showed good accuracy at induced low, normal, and high CO states in normal horses. Future studies performed under more clinical conditions will show if this monitor can help to assess hemodynamic status and guide therapy in horses in ICU settings and under general anesthesia.

The Incidence of Radial Artery Occlusion in Critically Ill Patients after Cannulation with a Long Catheter

Cardiac output monitoring is a common practice in critically ill patients. The PiCCO (pulse index continuous cardiac output) method requires artery cannulation. According to the manufacturer, the cannula in the radial artery should be removed after three days. However, longer monitoring is sometimes necessary. The aim of this study was to assess the incidence of radial artery occlusion (RAO) after three days of cannulation and to check whether five-day cannulation is related to a higher occlusion rate. An additional assessment was made to verify the presence of occlusion three, fourteen and thirty days after decannulation. The PiCCO cannula was inserted into the radial artery after the Barbeau test and Doppler assessment of blood flow. It was left for three or five days. Doppler was performed immediately after its removal and at three, fourteen and thirty days following decannulation. Thirty-seven patients were randomly assigned for three or five days of cannulation, and twenty-three of them were eligible for further analysis. RAO was found in thirteen (56.5%) patients. No statistical difference was found between the RAO rate for three and five day cannulations (p = 0.402). The incidence of RAO was lower when the right radial artery was cannulated (p = 0.022; OR 0.129). Radial artery cannulation with a PiCCO catheter poses a risk of RAO. However, the incidence of prolonged cannulation appeared to not increase the risk of artery occlusion. ClinicalTrials.gov ID NCT02695407.

Is there still a role for the oesophageal Doppler in cardiac output monitoring?

The oesophageal Doppler monitor received early endorsement as an effective emerging medical technology, although numerous alternatives have since been widely adopted. This article examines the evidence supporting the continued use of the oesophageal Doppler.

Central hemodynamic monitoring in patients with cardiogenic shock

Cardiogenic shock is the pathology most commonly encountered by intensive care physicians. Its frequency averages 410% in STEMI (ST-elevation myocardial infarction) patients and 24% in NONSTEMI (non-ST-elevation myocardial infarction) patients. Effective shock therapy is impossible without understanding the hemodynamic mechanisms of its occurrence. Many authors emphasize that cardiac output is the most important indicator of cardiac function, which necessitates its monitoring. Meanwhile, the cardiac output monitoring is associated with a number of difficulties, including those related to the technology of recording this function. In this article, the authors emphasize the importance of measuring central hemodynamic parameters in patients with predominantly cardiogenic shock. We have tried to structure the knowledge about different techniques of central hemodynamics monitoring, considered advantages and disadvantages of each of them. We believe that the data obtained by hemodynamic monitoring should be closely studied and used, because sometimes multidirectional mechanisms may be involved in the genesis of shock; therefore, therapy should be based on the data obtained in a particular patient.

Perioperative hemodynamic optimization: from guidelines to implementation—an experts’ opinion paper

Despite a large body of evidence, the implementation of guidelines on hemodynamic optimization and goal-directed therapy remains limited in daily routine practice. To facilitate/accelerate this implementation, a panel of experts in the field proposes an approach based on six relevant questions/answers that are frequently mentioned by clinicians, using a critical appraisal of the literature and a modified Delphi process. The mean arterial pressure is a major determinant of organ perfusion, so that the authors unanimously recommend not to tolerate absolute values below 65 mmHg during surgery to reduce the risk of postoperative organ dysfunction. Despite well-identified limitations, the authors unanimously propose the use of dynamic indices to rationalize fluid therapy in a large number of patients undergoing non-cardiac surgery, pending the implementation of a “validity criteria checklist” before applying volume expansion. The authors recommend with a good agreement mini- or non-invasive stroke volume/cardiac output monitoring in moderate to high-risk surgical patients to optimize fluid therapy on an individual basis and avoid volume overload. The authors propose to use fluids and vasoconstrictors in combination to achieve optimal blood flow and maintain perfusion pressure above the thresholds considered at risk. Although purchase of disposable sensors and stand-alone monitors will result in additional costs, the authors unanimously acknowledge that there are data strongly suggesting this may be counterbalanced by a sustained reduction in postoperative morbidity and hospital lengths of stay. Beside existing guidelines, knowledge and explicit clinical reasoning tools followed by decision algorithms are mandatory to implement individualized hemodynamic optimization strategies and reduce postoperative morbidity and duration of hospital stay in high-risk surgical patients.