Left ventricular-arterial coupling is associated with prolonged mechanical ventilation in severe post-cardiac surgery patients: an observational study

Abstract

BackgroundWeaning post-cardiac surgery patients from mechanical ventilation (MV) poses a big challenge to these patients. Optimized left ventricular-arterial coupling (VAC) may be crucial for reducing the MV duration of these patients. However, there is no research exploring the relationship between VAC and the duration of MV. We performed this study to investigate the relationship between left ventricular-arterial coupling (VAC) and prolonged mechanical ventilation (MV) in severe post-cardiac surgery patients.MethodsThis was a single-center retrospective study of 56 severe post-cardiac surgery patients from January 2015 to December 2017 at the Department of Critical Care Medicine of Peking Union Medical College Hospital. Patients were divided into two groups according to the duration of MV (PMV group: prolonged mechanical ventilation group, MV > 6 days; Non-PMV group: non-prolonged mechanical ventilation group, MV ≤ 6 days). Hemodynamics and tissue perfusion data were collected or calculated at admission (T0) and 48 h after admission (T1) to the ICU.ResultsIn terms of hemodynamic and tissue perfusion data, there were no differences between the two groups at admission (T0). Compared with the non-prolonged MV group after 48 h in the ICU (T1), the prolonged MV group had significantly higher values for heart rate (108 ± 13 vs 97 ± 12, P = 0.018), lactate (2.42 ± 1.24 vs.1.46 ± 0.58, P < 0.001), and Ea/Ees (5.93 ± 1.81 vs. 4.05 ± 1.20, P < 0.001). Increased Ea/Ees (odds ratio, 7.305; 95% CI, 1.181–45.168; P = 0.032) and lactate at T1 (odds ratio, 17.796; 95% CI, 1.377–229.988; P = 0.027) were independently associated with prolonged MV. There was a significant relationship between Ea/EesT1 and the duration of MV (r = 0.512, P < 0.01). The area under the receiver operating characteristic (AUC) of the left VAC for predicting prolonged MV was 0.801, and the cutoff value for Ea/Ees was 5.12, with 65.0% sensitivity and 90.0% specificity.ConclusionsLeft ventricular-arterial coupling was associated with prolonged mechanical ventilation in severe post-cardiac surgery patients. The assessment and optimization of left VAC might be helpful in reducing duration of MV in these patients.

A systemic congestive index (systemic pulse pressure to central venous pressure ratio) predicts adverse outcomes in patients undergoing valvular heart surgery

“…The cardiovascular system is intrinsically pulsatile in nature and is characterized by both ventricular‐arterial and ventricular‐ventricular interactions 15–17 . As shown in previous studies, ventricular‐arterial interactions have been associated with adverse outcomes in patients undergoing cardiac surgery 18 . SPP is influenced by ventricular‐arterial interactions and encompasses the combined effects of left ventricular contractile properties and arterial characteristics such as input impedance 19,20 .…”

“…[15][16][17] As shown in previous studies, ventricular-arterial interactions have been associated with adverse outcomes in patients undergoing cardiac surgery. 18 SPP is influenced by ventricular-arterial interactions and encompasses the combined effects of left ventricular contractile properties and arterial characteristics such as input impedance. 19,20 Thus, the SPP serves as a proxy for ventriculararterial interactions and can be utilized as a prognostic tool for patients undergoing valvular heart surgery.…”

Risk Factors for Prolonged Mechanical Ventilation and Weaning Failure: A Systematic Review

“…Risk factors identified as relevant for PMV or prolonged weaning include age [ 1 , 16 ], comorbidities (previous stroke, renal impairment, poor cardiac function, chronic obstructive pulmonary disease [COPD]) [ 17 , 18 , 19 , 20 , 21 ] and various laboratory parameters (low platelets, elevated blood urea nitrogen, elevated creatinine, low serum albumin, elevated blood glucose levels or hypernatremia) [ 16 , 18 , 19 , 20 , 22 , 23 ]. Blood gas analysis values (lower HCO 3 - or pH values or higher PaCO 2 ) as well as parameters of ventilator settings (FiO 2 ≥ 0.39, level of PEEP) [ 19 , 24 ] or gas exchange (PaO 2 /FiO 2 <200 mm Hg) [ 16 ] were also identified as relevant.…”

“…In addition to patients in medical or surgical ICUs without further specification, there were studies that included patients surviving sepsis with respiratory failure, tracheotomized patients undergoing MV, patients admitted to respiratory ICUs, or patients admitted to the ICU after cardiac surgery. Risk factors identified as relevant for PMV or prolonged weaning include age [1,16], comorbidities (previous stroke, renal impairment, poor cardiac function, chronic obstructive pulmonary disease [COPD]) [17][18][19][20][21] and various laboratory parameters (low platelets, elevated blood urea nitrogen, elevated creatinine, low serum albumin, elevated blood glucose levels or hypernatremia) [16, 18-20, 22, 23]. Blood gas analysis values (lower HCO 3 or pH values or higher PaCO 2 ) as well as parameters of ventilator settings (FiO 2 ≥ 0.39, level of PEEP) [19,24] or gas exchange (PaO 2 /FiO 2 <200 mm Hg) [16] were also identified as relevant.…”