Background: This study looked at the characteristics and outcomes of critically ill patients with confirmed influenza A(H1N1) pdm09 infection
in the Western Balkans in the post‑pandemic period. Materials and Methods: This retrospective observational study of medical records
and associated data collected during the post‑pandemic period included all mechanically ventilated adult patients of two university‑affiliated
hospitals of the Western Balkans between 1 January and 31 March 2019 who had influenza A(H1N1) pdm09 infection confirmed by real‑time
reverse transcriptase‑polymerase chain reaction from nasopharyngeal swab specimens and respiratory secretions. Results: The study included
89 patients, 49 males(55.1%), aged 56.09 ± 12.64 years. The median time from shift from hospital time to intensive care unit was 1 day (range:
1–2). In the post‑pandemic period, cases observed in this study were found to have the following comorbidities: cardiovascular diseases in
44 (49.4%) patients and diabetes in 21 (23.6%) patients. Thirty‑one patients (34.8%) in this study were obese. All 89 patients(100%) experienced
some degree of acute respiratory distress syndrome, and 39 (44%) had multiorgan failure. Eighty‑three patients (93%) were intubated and
mechanically ventilated, 6 (7%) received non‑invasive mechanical ventilation, 12 (13%) were treated with vvECMO and 36 (40%) received
renal replacement therapy. Vasoactive support was needed by 56 (63%) patients. The median duration of mechanical ventilation was 9 (6–15.5)
days. The hospital mortality rate was 44%. Conclusion: Critically ill patients with confirmed influenza A (H1N1) pdm09 infection in the
post‑pandemic season were older, required vasoactive drugs more often, and there was a trend of higher survival compared to H1N1 infection
patients in the previous pandemic seasons.
