Philip Marino

Pulmonary vascular and right ventricular dysfunction in adult critical care: current and emerging options for management: a systematic literature review

IntroductionPulmonary vascular dysfunction, pulmonary hypertension (PH), and resulting right ventricular (RV) failure occur in many critical illnesses and may be associated with a worse prognosis. PH and RV failure may be difficult to manage: principles include maintenance of appropriate RV preload, augmentation of RV function, and reduction of RV afterload by lowering pulmonary vascular resistance (PVR). We therefore provide a detailed update on the management of PH and RV failure in adult critical care.MethodsA systematic review was performed, based on a search of the literature from 1980 to 2010, by using prespecified search terms. Relevant studies were subjected to analysis based on the GRADE method.ResultsClinical studies of intensive care management of pulmonary vascular dysfunction were identified, describing volume therapy, vasopressors, sympathetic inotropes, inodilators, levosimendan, pulmonary vasodilators, and mechanical devices. The following GRADE recommendations (evidence level) are made in patients with pulmonary vascular dysfunction: 1) A weak recommendation (very-low-quality evidence) is made that close monitoring of the RV is advised as volume loading may worsen RV performance; 2) A weak recommendation (low-quality evidence) is made that low-dose norepinephrine is an effective pressor in these patients; and that 3) low-dose vasopressin may be useful to manage patients with resistant vasodilatory shock. 4) A weak recommendation (low-moderate quality evidence) is made that low-dose dobutamine improves RV function in pulmonary vascular dysfunction. 5) A strong recommendation (moderate-quality evidence) is made that phosphodiesterase type III inhibitors reduce PVR and improve RV function, although hypotension is frequent. 6) A weak recommendation (low-quality evidence) is made that levosimendan may be useful for short-term improvements in RV performance. 7) A strong recommendation (moderate-quality evidence) is made that pulmonary vasodilators reduce PVR and improve RV function, notably in pulmonary vascular dysfunction after cardiac surgery, and that the side-effect profile is reduced by using inhaled rather than systemic agents. 8) A weak recommendation (very-low-quality evidence) is made that mechanical therapies may be useful rescue therapies in some settings of pulmonary vascular dysfunction awaiting definitive therapy.ConclusionsThis systematic review highlights that although some recommendations can be made to guide the critical care management of pulmonary vascular and right ventricular dysfunction, within the limitations of this review and the GRADE methodology, the quality of the evidence base is generally low, and further high-quality research is needed.

Abnormal Lung Function in Adults With Congenital Heart Disease: Prevalence, Relation to Cardiac Anatomy, and Association With Survival

Background— Restrictive lung defects are associated with higher mortality in patients with acquired chronic heart failure. We investigated the prevalence of abnormal lung function, its relation to severity of underlying cardiac defect, its surgical history, and its impact on outcome across the spectrum of adult congenital heart disease. Methods and Results— A total of 1188 patients with adult congenital heart disease (age, 33.1±13.1 years) undergoing lung function testing between 2000 and 2009 were included. Patients were classified according to the severity of lung dysfunction based on predicted values of forced vital capacity. Lung function was normal in 53% of patients with adult congenital heart disease, mildly impaired in 17%, and moderately to severely impaired in the remainder (30%). Moderate to severe impairment of lung function related to complexity of underlying cardiac defect, enlarged cardiothoracic ratio, previous thoracotomy/ies, body mass index, scoliosis, and diaphragm palsy. Over a median follow-up period of 6.7 years, 106 patients died. Moderate to severe impairment of lung function was an independent predictor of survival in this cohort. Patients with reduced force vital capacity of at least moderate severity had a 1.6-fold increased risk of death compared with patients with normal lung function (P=0.04). Conclusions— A reduced forced vital capacity is prevalent in patients with adult congenital heart disease; its severity relates to the complexity of the underlying heart defect, surgical history, and scoliosis. Moderate to severe impairment of lung function is an independent predictor of mortality in contemporary patients with adult congenital heart disease.

Bosentan in pulmonary hypertension associated with fibrotic idiopathic interstitial pneumonia.

RATIONALE Pulmonary hypertension (PH) associated with fibrotic idiopathic interstitial pneumonia (IIP; idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia) confers important additional morbidity and mortality. OBJECTIVES To evaluate the safety and clinical efficacy of the dual endothelin-1 receptor antagonist bosentan in this patient group. METHODS In a randomized, double-blind, placebo-controlled study, 60 patients with fibrotic IIP and right heart catheter confirmed PH were randomized 2:1 to bosentan (n = 40) or placebo (n = 20). The primary study endpoint was a fall from baseline pulmonary vascular resistance index (PVRi) of 20% or more over 16 weeks. MEASUREMENTS AND MAIN RESULTS Sixty patients (42 men; mean age, 66.6 ± 9.2 yr), with a mean pulmonary artery pressure of 36.0 (± 8.9) mm Hg, PVRi 13.0 (± 6.7) Wood Units/m(2) and reduced cardiac index of 2.21 (± 0.5) L/min/m(2) were recruited to the study. Accounting for deaths and withdrawals, paired right heart catheter data were available for analysis in 39 patients (bosentan = 25, placebo = 14). No difference in the primary outcome was detected, with seven (28.0%) patients receiving bosentan, and four (28.6%) receiving placebo achieving a reduction in PVRi of greater than or equal to 20% (P = 0.97) at 16 weeks. There was no change in functional capacity or symptoms between the two groups at 16 weeks, nor any difference in rates of serious adverse events or deaths (three deaths in each group). CONCLUSIONS This study shows no difference in invasive pulmonary hemodynamics, functional capacity, or symptoms between the bosentan and placebo groups over 16 weeks. Our data do not support the use of the dual endothelin-1 receptor antagonist, bosentan, in patients with PH and fibrotic IIP. Clinical trial registered with www.clinicaltrials.gov (NCT 00637065).

Disease targeting therapies in patients with Eisenmenger syndrome: response to treatment and long-term efficiency.

OBJECTIVES To examine long-term efficacy of disease targeting therapies (DTT) in patients with Eisenmenger syndrome. METHODS All adult patients with Eisenmenger syndrome treated with DTT at our institution were included. Functional class (FC), oxygen saturation and 6-minute walk test distance (6 MWTd) were analysed retrospectively. RESULTS Between 2002 and 2010, 79 Eisenmenger patients (21 males, 16 with Down syndrome) aged 34 ± 10 years (range 17-68 years) were included. Median follow-up was 3.3 years (range 0.2 to 8.9 years). 6 MWTd increased early after initiation of DTT, with a plateau after approximately 3 years and no obvious trend towards a deterioration on average during longer-term follow-up. Two patients died during follow-up and escalation of treatment was required in 18 patients after a median period of 2.5 years. Escalation of therapy was also associated with an increase in 6 MWTd. In addition, FC improved on DTT and oxygen saturation, increased, both at rest and peak exercise. This effect was more pronounced in the patients with the lowest baseline oxygen saturation at rest. CONCLUSIONS Long-term DTT is safe and improves objective exercise capacity and subjective symptoms. Response to DTT was typically observed early after initiation of DTT and was, on average, maintained longer-term. However, 1 in 5 patients required escalation of DTT, with time, due to symptomatic deterioration and this was associated with an afresh improvement in 6 MWTd.

Six-minute walk test distance and resting oxygen saturations but not functional class predict outcome in adult patients with Eisenmenger syndrome

BACKGROUND Eisenmenger syndrome (ES) represents the extreme manifestation of pulmonary arterial hypertension in patients with congenital heart disease, associated with significant exercise intolerance and mortality. Even though of six-minute-walk-test (6MWT) is routinely used in these patients, little is known about its prognostic value in comparison to functional class. METHODS AND RESULTS We included 210 adult patients with ES who underwent a total of 822 6MWTs. Median walking distance (6MWD) was 330 m [IQR 260-395], oxygen saturation (SO2) at baseline 86% [IQR 82-91%] and SO2 at peak-exercise 69% [IQR 60-80%]. In patients commenced on advanced therapy for pulmonary hypertension, but not in the reminder, there was a significant improvement in walking distance (297±97 m vs. 325±87 m,P=0.0019), SO2 at rest (84.9±7.1 vs. 86.8±5.9%,P=0.003), SO2 at peak exercise (69.1±12.7 vs. 72.3±12.2%,P=0.04) and NYHA functional class (P=0.0047). During a follow up of 3.3 years, 29 patients died. On time-dependent Cox analysis, 6MWD (HR 0.94 per 10 m, 95%CI: 0.91-0.97,P<0.001) and baseline SO2 (HR 0.90, 95%CI:0.86-0.94,P<0.0001) were predictors of death. In contrast, age, functional class, peak-exercise SO2 and SO2 change were not related to mortality. A three-fold increased risk of death was identified in patients not reaching a 6MWD of 350 m or with baseline SO2 below 85%. CONCLUSIONS The 6MWD and resting SO2, but not functional class were predictive of outcome in this contemporary cohort of Eisenmenger patients and should be incorporated in both risk stratification and management algorithms for these patients.

Pathophysiology of pulmonary hypertension in acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome are characterized by protein rich alveolar edema, reduced lung compliance, and acute severe hypoxemia. A degree of pulmonary hypertension (PH) is also characteristic, higher levels of which are associated with increased morbidity and mortality. The increase in right ventricular (RV) afterload causes RV dysfunction and failure in some patients, with associated adverse effects on oxygen delivery. Although the introduction of lung protective ventilation strategies has probably reduced the severity of PH in ALI, a recent invasive hemodynamic analysis suggests that even in the modern era, its presence remains clinically important. We therefore sought to summarize current knowledge of the pathophysiology of PH in ALI.

C-reactive protein in adults with pulmonary arterial hypertension associated with congenital heart disease and its prognostic value

Objectives To assess the relationship of C-reactive protein (CRP) to clinical outcome and mortality in adults with pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD-PAH). Background Approximately 5–10% of adults with congenital heart disease (ACHD) develop PAH, which in turn is associated with substantial morbidity and mortality. Although CRP is known to predict outcome in idiopathic PAH, little is known regarding its prognostic value in CHD-PAH. Methods We obtained and analysed 1936 CRP values in a total of 225 adults with CHD-PAH (median age at study entry 34.0 years (27.0–41.7); 32.9% male, 35% with Down syndrome), performed over a 12-year period. High CRP values related to infection or blood transfusions were excluded from the analysis. Results During a median follow-up of 4.8 years (1149 patients-years), 50 patients died. The median CRP concentration on the last assessment was 5.0 mg/L (IQR 2.0–10.0), higher in deceased patients compared with survivors (11.5 mg/L (6.0–23.0) vs 4.0 mg/L (1.5–8.0), p<0.0001). Following univariate Cox regression analysis, CRP emerged as a strong predictor of mortality (HR 1.18; 95% CI 1.11 to 1.26, p<0.0001) and remained significant after adjustment for age, presence of Down syndrome and advanced PAH therapy. Survival–receiver–operator characteristic analysis identified an optimal cut-off value of 10 mg/L. Patients with CRP >10 mg/L had more than a threefold increased risk of death (HR 3.63, 95% CI 2.07 to 6.38, p<0.0001). Conclusions Serum CRP is a simple but powerful marker of mortality in CHD-PAH patients and should be incorporated in the risk stratification and routine assessment of these patients.

Association of haemodynamic changes measured by serial central venous saturation during ultrafiltration for acutely decompensated heart failure with diuretic resistance and change in renal function

BACKGROUND Patients with acute decompensated heart failure with diuretic resistance (ADHF-DR) have a poor prognosis. The aim of this study was to assess in patients with ADHF-DR, whether haemodynamic changes during ultrafiltration (UF) are associated with changes in renal function (Δcreatinine) and whether Δcreatinine post UF is associated with mortality. METHODS Seventeen patients with ADHF-DR underwent 20 treatments with UF. Serial bloods (4-6 hourly) from the onset of UF treatment were measured for renal function, electrolytes and central venous saturation (CVO2). Univariate and multivariate analysis were performed to assess the relationship between changes in markers of haemodynamics [heart rate (HR), systolic blood pressure (SBP), packed cell volume (PCV) and CVO2] and Δcreatinine. Patients were followed up and mortality recorded. Cox-regression survival analysis was performed to determine covariates associated with mortality. RESULTS Renal function worsened after UF in 17 of the 20 UF treatments (baseline vs. post UF creatinine: 164±58 vs. 185±69μmol/l, P<0.01). ΔCVO2 was significantly associated with Δcreatinine [β-coefficient of -1.3 95%CI (-1.8 to -0.7), P<0.001] and remained significantly associated with Δcreatinine after considering changes in SBP, HR and PCV [P<0.001]. Ten (59%) patients died at 1-year and 15(88%) by 2-years. Δcreatinine was independently associated with mortality (adjusted-hazard ratio 1.03 (1.01 to 1.07) per 1μmol/l increase in creatinine; P=0.02). CONCLUSIONS Haemodynamic changes during UF as measured by the surrogate of cardiac output was associated with Δcreatinine. Worsening renal function at end of UF treatment occurred in the majority of patients and was associated with mortality.

Pleural Effusions in the Critically Ill

Pleural effusions commonly occur in the critically ill and arise primarily through a combina-tion of organ failure (cardiac, renal, hepatic), sepsis and poor nutrition leading to hypoalbuminaemia. The incidence varies considerably, with estimates ranging from 8% to 60% depending on whether clinical or radiological criteria are applied. Effu-sions are typically defined in terms of transudates (protein content <30 g/dL) and exudates (<30 g/ dL). The nature and cause of a pleural effusion is usually determined by pleural fluid aspiration and analysis, together with non-invasive imaging such as chest radiography, ultrasound and computer-ised tomography (CT). Management is dependent on the underlying cause (e.g. heart failure, pneu-monia), effusion size and symptom severity. Treat-ment may be initially medical (thoracocentesis, diuretics, antibiotics), though surgical intervention (intercostal drains, pleurodesis, pleural shunts) may be required in more complex cases such as empyema or neoplasia.