Optimum needle length for DPT inoculation of Indian infants.

Correct placement of the injected DPT vaccine into the deep muscular layers decreases the local reactions, including the sterile abscess formation. However, recommendations on size of the needle to be used and the angle of injection are not easily available, are not uniform and are based on case reports. The only study based on scientific data of ultrasonographic measurement of fat layer and muscle layer thickness of thigh of only 24 infants of 4 months age covers only American children. (Hick et al, Pediatrics 1989; 84: 136-37). In the present study, we have produced similar data on 215 Indian children belonging to all those age groups in which DPT vaccinations are given. Mean thickness of skin + fat layer in the middle one-third of the anterolateral aspect of thigh was 1.03 +/- 0.23 cm, 1.04 +/- 0.21 cm, 0.95 +/- 0.19 cm and 1.06 +/- 0.27 cm in the age groups of 6-12 weeks (Groups I), 13-18 weeks (Group II), 19-24 weeks (Groups III) and 18 +/- 1 month (Group IV) respectively. These age groups correspond to the timings of first 3 primary doses and the first booster dose of the DPT vaccine in our immunization clinic. Mean thickness of all the soft tissues together at the same site were 1.87 +/- 0.35, 2.17 +/- 0.38, 2.07 +/- 0.39 and 2.07 +/- 0.26 cm respectively for the groups I to IV.(ABSTRACT TRUNCATED AT 250 WORDS)