Respiratory Viruses in Mechanically Ventilated Patients

A Pilot Study

Raquel Nazareth; Maria-Jesus Chasqueira; Maria-Lúcia Rodrigues; Carolina Paulino; Catarina Conceição; Lia Lêdo; Úrsula Segura; Madalena Santos; António Messias; Pedro Póvoa; Paulo Paixão

Disclosures

BMC Pulm Med. 2020;20(39) 

In This Article

Methods

Study Design

This was a prospective observational study analyzing mini-bronchoalveolar lavage (mini-BAL) samples of invasive mechanical ventilated patients from two polivalent Intensive Care Units (ICUs) of Lisbon district, in Portugal. Patients were divided in two groups; WORI group included patients admitted for causes other than respiratory infection and not receiving antibiotic therapy (respiratory symptoms were excluded at time of admission, namely cough and sputum; chest x-ray was performed in all the patients to exclude lower respiratory infection. It was not possible to obtain reliable information about the presence of respiratory symptoms before admission nor about influenza vaccination history). WRI group included patients admitted for acute respiratory infection and on antibiotic therapy. All patients enrolled in the study required endotracheal intubation to treat their acute respiratory failure.

Exclusion criteria were age less than 18 years, pregnancy, immunosupression and antiviral therapy on admission. The participants, or their legal representatives, were informed about the study objectives and their signed consents were obtained previously to the sample collection. The Ethic Committees of both participating centers approved the study protocol.

Patient demographics, comorbidities, Acute Physiology and Chronic Health Evaluation (APACHE) II score and Simplified Acute Physiology Score (SAPS) II, admission diagnosis and ICU clinical outcome were recorded.

Sample collection was performed with a Combicath® kit, between December 2016 and March 2017.

Mini-BAL procedure

A protected mini-BAL (with a double catheter, Combicath® kit (Plastimed, Saint-Leu-La Forêt, France)) was performed on the first 24 h after the tracheal intubation and invasive mechanical ventilation. A combicath was introduced blindly through the oro-tracheal tubeuntil its end on the lower third of the trachea and wedged in the bronchial tree. Mini-BAL samples were obtained by intilling 2 mL of room temperature saline solution (0.9%), followed by gentle suction after the infusion of each aliquot. Samples were stored at − 80 °C until processed.

Laboratory Methods

Clinical samples were processed using the QIAmp MinElute Virus Spin kit for extraction, according to the manufacturer's instructions (Qiagen, Valencia, CA).

"In house" real-time Taqman PCR and RT-PCR techniques, detailed elsewhere,[16] were used for the detection of DNA and RNA respiratory viruses: adenovirus, human bocavirus (HBoV), influenza virus A/B, respiratory syncytial virus (RSV), human parainfluenza virus (HPIV) types 1/3 and 2/4, human enterovirus (HEV), human rhinovirus (HRV), human metapneumovirus (HMPV), human coronavirus (HCoV) group 1 (229E, NL63) and 2 (OC43, HKU1).

Data Analysis

Descriptive analysis was performed, values are expressed as percentages for discrete variables, or as the mean for continuous variables.

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