Hemodynamic profile of pulmonary hypertension (PH) in ARDS

Abstract

Acute respiratory distress syndrome (ARDS) is a diffuse lung injury that leads to a severe acute respiratory failure. Traditional diagnostic criteria for pulmonary hypertension (PH), in this situation, may be unreliable due to the effects of positive pressure ventilation and vasoactive agents. The aim of this study is to describe the hemodynamic characteristics of PH secondary to ARDS, in relation with respiratory parameters. We assessed the hemodynamic, respiratory function, and ventilator parameters in a cohort of 38 individuals with ARDS-associated PH defined by mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg. Individual characteristics: PaO2/FiO2 = 110 ± 60 mmHg, alveolar-arterial oxygen gradient (A-aO2) = 549 ± 148.9 mmHg, positive end-expiratory pressure (PEEP) = 8.7 ± 3.5 cmH2O, pulmonary static compliance (Cstat) = 30 ± 12.1 L*cmH2O-1, mPAP = 35.4 ±6.6 mmHg, pulmonary artery wedge pressure (PAWP) = 15.6 ± 5.5 mmHg, cardiac index (CI) = 3.4 ± 1.2 L/min/m2, pulmonary vascular resistance (PVR) = 3.3 ± 1.6 Wood units (WU), right atrial pressure (RAP) = 13.4 ± 5.4 mmHg, diastolic pulmonary gradient (DPG) = 12.6 ± 6.5 mmHg, and trans-pulmonary gradient (TPG) = 19.7 ± 7.7 mmHg. The composite marker—DPG >7 mmHg and PVR > 3 WU—is associated with lower CI (P = 0.016), higher mPAP (P = 0.003), and lower pulmonary static compliance (P = 0.028). We confirmed a poor prognosis of ARDS associated with PH, with a 50% survival rate after 17 days. We observed that the survival rate at 28 days was better in the case of improvement in the PaO2/FiO2 ratio in the first 24 h (log rank P = 0.003). ARDS associated with PH is a severe condition with a very poor survival rate. The composite marker DPG > 7 mmHg and PVR > 3 WU seemed to better describe the hemodynamic and respiratory dysfunction. The improvement in PaO2/FiO2 ratio in the first 24 h defined a better survival in our cohort of patients.

Pulmonary hypertension and right ventricular involvement in hospitalised patients with COVID-19

“…Downloaded from The association between severe acute respiratory failure and PH has been demonstrated by several studies, mainly focusing on critically ill patients treated in ICU setting. [21][22][23][24] Secondary alterations of pulmonary vascular haemodynamics during acute respiratory distress syndrome (ARDS) are multifactorial, depending on hypoxia, vascular remodelling or compression by oedema or fibrosis, increased alveolar pressure, vasoconstriction, local thrombosis or pulmonary embolism, and reduced pulmonary compliance and use of PEEP. 4 5 7 25 While the advanced stages of COVID-19 are characterised by severe ARDS and need of mechanical ventilation (and the mentioned pathophysiological mechanisms could be directly translated to such scenario), whether a less-advanced SARS-CoV-2 pneumonia could determine a significant change in pulmonary vascular haemodynamics leading to PH and RV involvement was unknown.…”

Mechanisms of Pulmonary Hypertension in Acute Respiratory Distress Syndrome (ARDS)

“…In addition to this high prevalence and despite best measures, ARDS has a high mortality rate of up to 45% (Bellani et al, 2016 ). Treatment of ARDS is complex, involving ventilatory and non-ventilatory management strategies including conservative fluid management, low tidal volume ventilation, prone positioning, inhaled vasodilator therapy and in refractory cases, extra corporeal membrane oxygenation (Peek et al, 2009 ; Calcaianu et al, 2017 ).…”

“…ARDS is a complex disease with multifactorial consequences; as such, in addition to elevated mPAP, other parameters have been strongly associated with mortality such as partial pressure of carbon dioxide (PaCO 2 ), partial pressure of oxygen (PaO 2 ), or PaO 2 /fraction of inspired oxygen (FiO 2 ). Additionally, pulmonary vascular dysfunction, as measured by an increase in transpulmonary pressure gradient and PVR, was associated with increased mortality in ARDS patients (Monchi et al, 1998 ; Meduri et al, 2009 ; Bull et al, 2010 ; Calcaianu et al, 2017 ). In addition, the composite marker diastolic pulmonary gradient >7 mmHg and PVR >3 Wood Units (WU) seemed to provide a better description of hemodynamic and respiratory dysfunction than other measurements, correlating with a more severe illness and worse patient outcomes (Calcaianu et al, 2017 ).…”

“…Additionally, pulmonary vascular dysfunction, as measured by an increase in transpulmonary pressure gradient and PVR, was associated with increased mortality in ARDS patients (Monchi et al, 1998 ; Meduri et al, 2009 ; Bull et al, 2010 ; Calcaianu et al, 2017 ). In addition, the composite marker diastolic pulmonary gradient >7 mmHg and PVR >3 Wood Units (WU) seemed to provide a better description of hemodynamic and respiratory dysfunction than other measurements, correlating with a more severe illness and worse patient outcomes (Calcaianu et al, 2017 ). These findings are summarized in Table 2 and underscore disruptions in the lung vasculature in ARDS as potential disease-amplifying effects that are not fully understood.…”

Pulmonary hypertension with adult respiratory distress syndrome: prevalence, clinical impact, and association with central venous pressure

“… 7 Although the importance of ACP identification and prevention is widely accepted in the management of ARDS, 6 , 8 the prevalence, progression, and prognosis of PH associated with ARDS, has not been fully investigated. 9 Additionally, scoring criteria have been limited to the field of mechanical ventilation (pneumonia as a cause of ARDS and driving pressure) and gas exchange (PaCO 2 and PaO 2 /FiO 2 ) and have not involved any hemodynamic monitoring parameters; notably, CVP has been associated with prognosis in critically ill patients 10 – 12 and should be included during the evaluation and identification of PH.…”