Original Article
Thromboembolic events in patients with severe pandemic influenza A/H1N1

https://doi.org/10.1016/j.ejim.2015.08.017Get rights and content

Abstract

Background

The 2009 pandemic influenza A/H1N1 developed as a novel swine influenza which caused more diseases among younger age groups than in the elderly. Severe hypoxemic respiratory failure from A/H1N1 pneumonia resulted in an increased need for ICU beds. Several risk groups were identified that were at a higher risk for adverse outcomes. Pregnant women were a particularly vulnerable group of patients The CDC reported on the first ten patients with severe illness and acute hypoxemic respiratory failure associated with A/H1N1 infection, none of whom were pregnant, but they noticed that half of the patients had a pulmonary embolism.

Methods

During a four-month period from September to December 2009, 252 patients were admitted to our hospital with confirmed pandemic influenza H1N1 by real-time reverse transcriptase-polymerase chain reaction test (rRT-PCR). We cared for twenty patients (7.9%) admitted to MICU with severe A/H1N1. Results on Thrombotic events were identified in five (25%) of our critically ill patients.

Conclusions

We recommend that patients with severe influenza A/H1N1 pneumonitis and respiratory failure be administered DVT prophylaxis in particular if there are additional risk factors for TVE. Further prospective studies on the relationship of influenza A/H1N1 and VTE are needed.

Introduction

The 2009 pandemic influenza A/H1N1 developed as a novel swine influenza which caused more diseases among younger age groups than in the elderly [1]. Although not as devastating as the 1918 Spanish Flue, it did cause more than 17,700 deaths worldwide. Severe hypoxemic respiratory failure from A/H1N1 pneumonia resulted in an increased need for ICU beds [2]. Several risk groups were identified that were at a higher risk for adverse outcomes [2]. Pregnant women were a particularly vulnerable group of patients; in the Californian cohort of 94 pregnant women with A/H1N1, 18 required ICU admissions and among them 6 died [3]. The CDC reported on the first ten patients with severe illness and acute hypoxemic respiratory failure associated with A/H1N1 infection, none of whom were pregnant, but they noticed that half of the patients had a pulmonary embolism [4]. This is in contrast to the findings from a Dutch group that patients with proven pulmonary embolism were less likely to have evidence of recent influenza illness than a control group in whom pulmonary embolism had been ruled out [5].

We report our experience with five patients that suffered clinically striking thrombotic events among 20 patients admitted to the medical intensive care unit (MICU) with severe A/H1N1.

Section snippets

Methods and results

During a four-month period from September to December 2009, 252 patients were admitted to our hospital with confirmed pandemic influenza H1N1 by real-time reverse transcriptase-polymerase chain reaction test (rRT-PCR). We cared for twenty patients (7.9%) admitted to MICU with severe A/H1N1 (Table 1); seven men and 13 women. Their mean age (SD) was 36 (14) years (range: 19–67). None had received vaccination. All patients received oseltamivir as soon as the suspicion of A/H1N1 was raised in

Discussion

We reported on five patients (25%) among 20 severely ill ICU patients with proven A/H1N1 pandemic infection, who experienced a clinically significant thrombotic event among them two arterial thrombotic events in two young pregnant women: CVA and acute myocardial infarction. Three patients had DVT without an underlying central line. All three women were pregnant and two of them succumbed to their severe illness.

One report has described thromboembolic events (TVE) as a complication in proven

Conflict of interests

The authors have no conflicts of interest to report and they have not been paid for the work submitted.

References (16)

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