Comparison of demographic, clinical, radiological characteristics and comorbidities in mechanically ventilated and nonventilated, adult patients admitted in ICU with confirmed diagnosis of influenza A (H1N1).

INTRODUCTION: Influenza A(H1N1) infection affected Indian population in 2009. Patients needed ICU admission and monitoring. Simple demographic, clinical and radiological variables are described in this article in mechanically ventilated and nonventilated patients. OBJECTIVES: To describe and correlate demographic, clinical, radiographic characteristics and comorbidities in mechanically ventilated and nonventilated, adult patients admitted in ICU with confirmed diagnosis of Influenza A(H1N1) infection. MATERIAL AND METHODS: Retrospective study of records of 100 RT-PCR confirmed patients with Influenza A (H1N1) infection from August 2009 to March 2010 was done. Each patient underwent an evaluation to determine demographic, clinical and radiographic features, comorbidities, mechanical ventilator required or not. RESULTS: 35 Patients required mechanical ventilation. 27 required IMV, 4 required NIMV while 4 patients initially were put on NIMV required IMV subsequently. 19 (40.42%) female patients required mechanical ventilator. Mean age of mechanically ventilated patients was 33 years, mean duration of illness was 7.9 days, mean duration of hospital stay was 6.8 days. 07 (20.00%) patients with pregnancy, 05 (14.29%) with DM, 05 (14.29%) with HT, 04/11.43%) with obesity required mechanical ventilator. 97.14% patients with fever, 88.54% with breathlessness, 11.43% with haemoptysis, 31.42% patients with throat pain required mechanical ventilator. However except Tachypnoea (p <0.01) no other symptom was statistically significant for mechanical ventilation 33(36.26%) patients with abnormal X ray,16 (80.00%) patients with right sided, 09(60.00%) patients with left sided and 40(71.43%) patients with bilateral disease required mechanical ventilator, right sided (p < 0.01) and bilateral (p <0.01) disease is statistically significant for requirement of mechanical ventilator. 33(47.14%) patients with lower zone involvement, 44 (67.70%) patients with middle zone and 23 (47.92%) patients with upper zone involvement required mechanical ventilator. Upper zone disease (p < 0.01) and middle zone disease (p < 0.01) is statistically significant for requirement of ventilator. 23 (47.92%) patients with right upper zone, 29 (42.64%) patients with right middle zone, 29 (46.77%) with left middle zone, 32 (42.67%) with right lower zone involvement required mechanical ventilator. RUZ (p < 0.01), RMZ (p < 0.01), LMZ (p < 0.001) and RLZ (p < 0.01) involvement had statistical significance for requirement of mechanical ventilator. 20 (33.89%) patients with patchy consolidation, 08 (36.36%) patients with reticulonodular and 05 (50.00%) patients with nodular pattern required mechanical ventilator however none of the pattern is statistically significant for mechanical ventilator. 08 (72.72%) patients with 6 zone involvement, 05 (50.00%) patients with single zone, 08 (40.00%)patients with 4 zone and 06 (33.33%) patients with 3 zone involvement required mechanical ventilator,however none was statistically significant for mechanical ventilator. All four patients requiring NIMV survived, while 28 died out of 31 on IMV. CONCLUSIONS: Mechanical ventilation requirement was more in females, in presence of comorbidities like pregnancy, DM, HT, in presence of tachypnoea, in presence of bilateral disease and in presence of middle zone and right upper zone disease and with multiple zone disease. All patients with heart involvement required mechanical ventilator. If there is radiological finding of right upper zone involvement, then, there is more probability that these patients require mechanical ventilator for case management. Similarly, RMZ, LMZ and RLZ and cardiomegaly if shown in X-ray, the necessity of ventilator management is more.

Clinicoradiologic correlation in adult patients diagnosed with novel influenza A (H1N1).

BACKGROUND: Influenza A(H1N1) infection affected Indian population in 2009. Patients needed ICU admission and monitoring. OBJECTIVES: To describe and correlate clinical and radiographic features of Influenza A(H1N1) infection in patients hospitalised in Intensive care unit. MATERIAL AND METHODS: Retrospective study of records of 100 RT-PCR confirmed patients with Influenza A(H1N1) infection from August 2009 to March 2010 was done. Each patient underwent an evaluation to determine clinical and radiographic features. RESULTS: Mean age of the patients was 33.43 years (+/- 12.152) with maximum patients between 18-40 years, with 53% males and 43% females. Cough (96%), Fever (95%), breathlessness (83%), throat pain (34%), crepitations (69%), Tachypnoea (59%)were the prominent symptoms and signs. 61% (n = 63) had comorbid condition like pregnancy (n = 13,20.63%), Diabetes Mellitus (DM) (n = 12,19.05%), HT (n = 11,17.60%), Obesity (n = 10, 15.87%) and Rheumatic Valvular Heart Disease (RVHD) (n = 6,09.52%). Chest X ray was abnormal in 91% patients and normal in 09% pts. Bilateral findings were seen in 61.53% cases. Most common zones affected were lower zones (77.46%), then middle zones (71.42%), followed by upper zones (42.7%). Most common patterns were consolidation (64.83%), reticulonodular (24.17%) and nodular (10.98%). 27.47% had two, 21.97% had four, 19.78% had three,12.08% had six, 7.69% had five and 10.98% had single zone involvement. Fever, cough and tachypnoea were present in all 100% pts with nodular pattern while crepitations were observed in 79.66% cases of consolidation. Patchy consolidation was seen in comorbidities like pregnancy (n = 10) and obesity (n = 06), while reticulonodular pattern was observed in hypertensive patients (n = 06). Maximum number of deaths were between 21 and 30 years of age (60.71%). Total number of deaths were 28 with 60.71% (n = 17) deaths between 21 and 30 years of age. Deaths were more in presence of comorbidities like Pregnancy (n = 5, 17.85%), Hypertension (n = 4,14.28%), Diabetes (n = 3 10.21%) and RVHD (n = 3,10.71%), in presence of RLZ involvement (92.85%), RMZ (89.28%), LMZ (85.21%) and RUZ involvement (71.42%), with consolidation pattern (57.14%) followed by reticulonodular pattern (21.42%) and in presence of six zone involvement (36.37%) followed by four zone (35%) and then by three(33%) and two (32%) zone involvement. Mean duration of hospital stay was 9.1 days. 23% patients stayed for less than 5 days, 41% stayed between 9 and 14 days while only 7% required to stay for more than 15 days. 37% pts showed normal Xray at the time of discharge or death. 38% patients showed persistence of radiological lesion at discharge or death. CONCLUSIONS: Young to middle age patients were commonly affected. Common comorbidities were Pregnancy, Diabetes, Hypertension, and Obesity and patients had fever, cough, breathlessness, tachypnoea, crepitations as common clinical features. Radiologically it was multizonal, bilateral disease with predominant lower zone involvement and common patterns were consolidation followed by reticulonodular and nodular. Patchy consolidation was more common in pregnancy and obesity while reticulonodular pattern was more in hypertensive patients. Fever, cough and tachypnoea were present in all 100% pts with nodular pattern. Crepitations were common in pts with consolidation. Clinical recovery preceded radiological recovery. Young to middle aged individuals died more. Deaths were more in presence of comorbidities like Pregnancy, HT, DM and RVHD, also with RLZ, RMZ, LMZ involvement and with consolidation pattern and with six zone involvement.

Retrospective analysis of necropsy findings in patients of H1N1 and their correlation to clinical features.

India reported its first case of H1N1 in July 2009 in Pune and since then, the number of reported cases and deaths exploded in India. Since very little data is available about histopathological findings in patients of H1N1 fatal cases in India, a retrospective chart analysis of necropsy findings of 15 cases of 2009 H1N1 fatal cases was performed. Common clinical features were fever, cough, and breathlessness followed by sore throat and rhinorrhea. Common lung findings were mononuclear cell infiltration, thick alveolar septae, intraalveolar hemorrhage. The other findings were congested pulmonary blood vessels, pulmonary edema, cytomegaly, fibrin accumulation and formation of eosinophilic membrane. These findings are suggestive of diffuse alveolar damage (DAD) and DAD with hemorrhage. All patients who underwent necropsy had radiographic findings suggestive of unilobar or multilobar pneumonia. This clinical finding can be correlated pathologically in these patients as all of them had either polymorphonuclear or mononuclear infiltrate. Furthermore, necrotizing pneumonitis pattern seen on these patients is the likely cause of mortality in these patients. Although clinical ARDS pattern was noted in all these patients, it was well correlated in lung pathology in all these cases.