Reduction in membrane component of diffusing capacity is associated with the extent of acute pulmonary embolism

Abstract

Acute pulmonary embolism (PE) often decreases pulmonary diffusing capacity for carbon monoxide (DL,CO), but data on the mechanisms involved are inconsistent. We wanted to investigate whether reduction in diffusing capacity of alveolo-capillary membrane (DM) and pulmonary capillary blood volume (Vc) is associated with the extent of PE or the presence and severity of right ventricular dysfunction (RVD) induced by PE and how the possible changes are corrected after 7-month follow-up. Forty-seven patients with acute non-massive PE in spiral computed tomography (CT) were included. The extent of PE was assessed by scoring mass of embolism. DL,CO, Vc, DM and alveolar volume (VA) were measured by using a single breath method with carbon monoxide and oxygen both at the acute phase and 7 months later. RVD was evaluated with transthoracic echocardiography and electrocardiogram. Fifteen healthy subjects were included as controls. DL,CO, DL, CO/VA, DM, vital capacity (VC) and VA were significantly lower in the patients with acute PE than in healthy controls (P<0·001). DM/Vc relation was significantly lower in patients with RVD than in healthy controls (P = 0·004). DM correlated inversely with central mass of embolism (r = −0·312; P = 0·047) whereas Vc did not. DM, DL,CO, VC and VA improved significantly within 7 months. In all patients (P = 0·001, P = 0·001) and persistent RVD (P = 0·020, P = 0·012), DM and DL,CO remained significantly lower than in healthy controls in the follow-up. DM was inversely related to central mass of embolism. Reduction in DM mainly explains the sustained decrease in DL,CO in PE after 7 months despite modern treatment of PE.

N-terminal Pro-brain Natriuretic Peptide, High-sensitivity Troponin and Pulmonary Artery Clot Score as Predictors of Right Ventricular Dysfunction in Echocardiography

“…Acute pulmonary embolism Q3 24 displays a wide spectrum of clinical severity. Rapid risk strati- 25 fication is crucial for the clinical management of patients with 26 APE. Haemodynamic status on admission is considered the 27 most important prognostic factor in terms of short-term mor-28 tality [3,4].…”

“…An arterial blood gas analysis was carried out on admis- Computed Tomography Pulmonary Angiography was per-138 formed as previously described [24,25]. The volume of con- The mass of embolism was scored using the method of 147 Mastora et al [26], in which the percentage of obstructed 148 surface of each artery is evaluated using a five-point scale.…”

The TL,NO/TL,CO ratio cannot be used to exclude pulmonary embolism

“…reported lowered T L,CO in acute PE similar to the values found by Wimalaratna et al . (74% of predicted) which were still lowered after seven months (Piirilä et al ., ). The T L,CO values we found (69% of predicted) are comparable with the results of both Wimalaratna et al .…”

“…(), but it is hard to compare these values to acute PE. In , Piirilä et al . reported lowered T L,CO in acute PE similar to the values found by Wimalaratna et al .…”

Exertional Desaturation as a Predictor of Rapid Lung Function Decline in COPD: Consider Pulmonary Embolic Disease and Pulmonary Hypertension Too

“…Restrictive ventilator defects with reduction in both FEV 1 and forced vital capacity have been reported in pulmonary embolic disease and pulmonary hypertension by mechanisms that are not yet clear (although secondary localized fibrosis has been postulated in chronic thromboembolic pulmonary hypertension) [2,3,4]. Finally, P-wave dispersion (independent of lung function) can occur as an early phenomenon in pulmonary hypertension in COPD, causing atrial arrhythmias.…”