Diagnosis of ventilator-associated pneumonia: comparison between ante-mortem and post-mortem cultures in trauma patients

PURPOSE

To evaluate the diagnostic utility of ante-mortem tracheal aspirates for diagnosis of ventilator-associated pneumonia (VAP). Trauma victims represent an otherwise healthy population, who are on multiple invasive life-support devices, which predispose them to severe infections like VAP. The diagnosis of VAP is challenging, due to the difficulty in obtaining a representative sample from lungs. We studied the diagnostic utility of tracheal aspirates by comparing its results with the post-mortem lung cultures.

MATERIALS AND METHODS

A total of 106 fatal trauma patients were included in the study. Lung samples and cardiac blood were taken for culture at the time of autopsy. The results of ante-mortem and post-mortem cultures were compared.

RESULTS

Septicemia was the cause of death in 51 (48%) of the fatal cases and VAP was identified in 36 (34%) cases. A total of 96 (90.5%) cases had pathogens isolated from lung samples. In 62 (58%) cases, the same organism was isolated from ante-mortem and post-mortem respiratory samples.

CONCLUSIONS

Culture results of a properly collected tracheal aspirate should be taken into consideration along with Centre for Disease Control and Prevention (CDC's) diagnostic criteria to maximise the diagnosis of VAP.

Factor V Leiden and prothrombin gene G20210A mutations are uncommon in portal vein thrombosis in India

BACKGROUND

Extra-hepatic portal vein obstruction due to portal vein thrombosis (PVT) is an important cause of portal hypertension in several regions including India. The cause of thrombosis in these patients remains unclear. We studied the frequency of mutations in genes for coagulation factors V and II (prothrombin) in 61 Indian patients with PVT and 49 healthy control subjects.

METHODS

The presence of factor V Leiden mutation and of G20210A prothrombin gene mutation was determined using polymerase chain reaction followed by restriction fragment length polymorphism. Chi-squared test was used to compare patients and controls.

RESULTS

Of the 61 patients (median age 11 years; 47 male) studied, 49 were children. One of 61 (1.6%) patients with PVT was heterozygous for factor V Leiden mutation and none had the G20210 prothrombin gene mutation. The frequencies of these mutations were not different from those in control subjects (2/49 and 0/46, respectively).

CONCLUSION

Factor V Leiden and G20210 prothrombin gene mutations are infrequent in Indian patients with PVT. Thus, these mutations are unlikely to be responsible for PVT in the Indian population.

Low frequency of factor V Leiden and prothrombin G20210A mutations in patients with hepatic venous outflow tract obstruction in northern India: a case-control study

BACKGROUND

Factor V Leiden (FVL) and prothrombin gene (G20210A) mutations are known to be associated with venous thromboembolism. Several studies have shown an association of these mutations with hepatic venous outflow tract obstruction (HVOTO). We studied the prevalence of these mutations among patients with HVOTO in northern India in comparison with healthy population.

METHODS

Genomic DNA from patients with HVOTO and healthy controls was analyzed for the presence of FVL and prothrombin gene G20210A mutations, using PCR and restriction-fragment length polymorphism.

RESULTS

Fifty-nine patients with HVOTO (age 5-69 years, median 27; 39 male) and 49 unrelated healthy controls from the same geographic region were studied. Of the 59 patients, 19 had a block in the hepatic vein, 7 in inferior vena cava, and 33 had mixed block. Presentation was with acute thrombosis in 9 patients and with long-standing obstruction in 50 patients. Among 49 controls, heterozygous and homozygous FVL mutations were observed in 2 and 0 subjects, respectively, with an allele frequency of 2% (2 of 98). In comparison, among 59 patients with HVOTO, four had heterozygous and none had homozygous FVL mutation, with an allele frequency of 3.4% (p=ns versus controls). The G20210A prothrombin gene mutation was not found in any of the patients or controls.

CONCLUSION

FVL and prothrombin G20210A mutations appear to have no role in the pathogenesis of HVOTO in our patients with Budd-Chiari syndrome, consisting largely of those with long-standing obstruction of the inferior vena cava.

Hepatitis B virus genotype A is more often associated with severe liver disease in northern India than is genotype D

BACKGROUND

The clinical outcome of chronic hepatitis B may depend on hepatitis B virus (HBV) genotype. Data from India on this aspect are limited and contradictory. We studied the frequency of HBV genotypes and their clinical significance.

METHODS

Stored sera from patients with chronic HBV infection were tested for HBV genotype using PCR-RFLP. Clinical data, and biochemical and serological parameters were retrieved from medical records; patients were classified as having chronic hepatitis or cirrhosis.

RESULTS

Of 70 patients studied (mean age [SD] 38.4 [17.0] years; 63 men; ALT 140 [177] U/L), 32 had chronic hepatitis and 38 had cirrhosis. HBeAg was positive in 50/67 (75%), and anti-HBe in 12/66 (18%). Genotype A was the commonest (37; 53%), followed by D (32; 46%) and C (1; 1%). Patients with genotype A more often had ALT elevation exceeding 1.5 times normal (30/37 [81%] than those with genotype D (18/31 [58%]; p< 0.05). They also more often had positive HBeAg (32/37; 86%) and negative anti-HBe (33/36; 92%) than those with genotype D (18/29 [62%] and 21/29 [72%], respectively; p< 0.05 each). Of 37 patients with genotype A, 23 (62%) had cirrhosis and 14 (38%) had chronic hepatitis; of 32 patients with genotype D, 15 (47%) had cirrhosis and 17 (53%) had chronic hepatitis (p=ns). In the subgroup aged> 25 years, genotype A patients more often had cirrhosis than those with genotype D (23/28 [82%] vs 13/23 [57%]; p < 0.05).

CONCLUSION

HBV genotypes A and D were the commonest in our population. Genotype A was more often associated with ALT elevation, HBeAg positivity, absence of anti-HBe and, among those aged 25 years and above, cirrhosis of liver, than was genotype D.