# Elevated D-dimer Levels in the Exacerbation of End-Stage Chronic Obstructive Pulmonary Disease (COPD) With Hypercapnia

## TL;DR

This case study shows that very high D-dimer levels in a COPD patient with severe symptoms may not indicate a blood clot in the lungs.

## Contribution

The study highlights that elevated D-dimer levels in end-stage COPD with hypercapnia may not always signal pulmonary embolism.

## Key findings

- The patient had a very high D-dimer level of 5.58 μg/mL without evidence of pulmonary embolism.
- Severe COPD with hypercapnic respiratory failure was the likely cause of elevated D-dimer levels.
- The case supports the idea that high D-dimer levels in COPD exacerbations may not require immediate clot-focused treatment.

## Abstract

D-dimer levels can be elevated in a variety of conditions including pulmonary embolism, deep vein thrombosis, disseminated intravascular coagulation, pregnancy, cigarette smoking, and infection. It has been proposed that D-dimer levels in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) can predict short-term and long-term survival. Here, we present a case of an elderly male who presented to the hospital with shortness of breath with an oxygen saturation of 77% on his two liters of home nasal cannula. He had a history of chronic obstructive pulmonary disease (COPD), heart failure with preserved ejection fraction (HFpEF), coronary artery disease, and current tobacco use. Labs indicated an elevated D-dimer level of 5.58 μg/mL. He was admitted to the intensive care unit (ICU) due to severe symptoms, which improved on bilevel positive airway pressure (BiPAP). His chest X-ray showed bilateral interstitial opacities with hyperexpansion. A computed tomography (CT) angiogram of the lungs did not show pulmonary embolism, but chronic bronchitis and severe emphysematous changes were evident. The patient’s elevated D-dimer levels coincided with acute hypercapnic respiratory failure from end-stage (Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage IV) COPD. The patient’s hospital course was complicated by pneumothorax on day 10 of admission. He was managed conservatively and transferred to long-term acute care due to the continued need for BiPAP support and a high-flow nasal cannula. This case and others continue to support that even very high levels of D-dimer in symptomatic patients may not indicate the presence of pulmonary embolism.