A Retrospective Study to Assess the Outcome  of Ventilatory Support in Patients with H1N1 (swine flu)  Influenza in Isolation ICU: Our Institutional Experience

Neena  Jain; Surendra  Kumar Sethi; Veena  Mathur; Veena   Patodi; Satveer Singh Gurjar; Saurav  Singh

Neena Jain M.D., Senior Professor And Head, Department Of Anaesthesia, J.l.n. Medical College And Hospital, Ajmer, Rajasthan
Surendra Kumar Sethi M.D., Assistant Professor, Department Of Anaesthesia, J.l.n. Medical College And Hospital, Ajmer, Rajasthan.
Veena Mathur M.D., Professor, Department Of Anaesthesia, J.l.n. Medical College And Hospital, Ajmer, Rajasthan
Veena Patodi M.D., Senior Professor, Department Of Anaesthesia, J.l.n. Medical College And Hospital, Ajmer, Rajasthan
Satveer Singh Gurjar M.D., Assistant Professor, Department Of Anaesthesia, J.l.n. Medical College And Hospital, Ajmer, Rajasthan.
Saurav Singh Junior Resident, Department Of Anaesthesia, J.l.n. Medical College And Hospital, Ajmer, Rajasthan

Keywords: H1N1 influenza A; Swine flu; Ventilatory support; Non invasive ventilation; Invasive ventilation; Acute respiratory distress syndrome

Abstract

ABSTRACT
Background: In 2009, an outbreak of swine flu caused by swine-origin influenza AH1N1 virus occurred in Mexico which spread rapidly throughout the world. Acute respiratory distress syndrome (ARDS) is a life threatening complication of H1N1 pneumonia which requires early invasive mechanical ventilation. There is limited literature on the use of non invasive ventilation in these patients which poses a challenge for the anaesthesiologist as intensivist.
Material and Methods: This retrospective analysis was conducted on the patients who were admitted in the swine flu isolation ward/ICU of our hospital during one year period. All the medical records were evaluated retrospectively and the data of clinical presentation of all the patients at the time of admission in isolation ward were recorded. The patients included in the study were evaluated and studied on the basis of various parameters which included the clinical presentation at the time of admission, associated co-morbidities, ventilatory modes offered to the patients on the basis of disease severity and their final outcome.
Results: Atotal of 277 patients were analyzed, out of which 102 patients were H1N1 positive. 40 patients were offered ventilatory support either as non invasive (NIV) or invasive ventilation (IV) or switched over from non invasive to invasive ventilation. Among them, the majority of patients i.e. 29 (73%) patients had associated co-morbidities. Out of 40 patients who required ventilatory support, 12 (30%) patients were discharged, 9 (22%) patients were left against medical advice and 16 (40%) patients expired during the course of treatment in ICU. So the overall mortality among the patients who required ventilatory support was 40% and survival rate was 58% for the patients who were offered NIV as the initial mode of treatment and continued till their recovery or transferred out.
Conclusion: NIV can be considered effective to manage patients with acute hypoxaemic respiratory failure and may be preferred over IV to manage the patients with mild to moderate influenza AH1N1 related ARDS in the absence of associated co-morbidities or multi organ dysfunction with better outcome.