The Indian Journal of Tuberculosis - LRS Institute of Tuberculosis ...

Original Article Ind. J. Tub., 1992, 39, 29
LOWER LUNG FIELD TUBERCULOSIS - A TROHOC ANALYSIS
P. Ravindran 1 , M. Joshi 2 , P. Sundaram 2 , R. Jose Raj 3 and K. Parameswaran 4
(Received on 15.5.90; Accepted on 5.6.91)
Summary. Pulmonary Tuberculosis occasionally
presents with atypical features, lower lung field
tuberculosis being one among them At trohoc
analysis of all tuberculosis admissions done
during a period of 5 years-from 1985 to 1989-ibiind
20 cases (2.4%) of lower lung field tuberculosis.
Lower lung field tuberculosis was more common in
diabetic (13.8%) than in n6n-diabetic tuberculosis
patients (1.4%) , the difference being statistically
significant (P< 0.005). It was also observed that
diagnosis of pulmonary tuberculosis on
radiological evidence alone was made more often
(40%) in diabetes msellitus than in patients
without diabetes (12.1%).
Introduction
It is well known that diabetics have a higher
chance of developing pulmonary tuberculosis,
among whom the disease has quite often an
atypical presentation. Lower lung field
tuberculosis is one such presentation.
Material and Methods
This study examines the proportion of those
with diabetes mellitus among hospitalized
patients of pulmonary tuberculosis, and the
extent of lower lung field tuberculosis in them.
The study design adopted was a Trohoc Analysis'
(retrospective cohort) whereby patients with
pulmonary tuberculosis were retrospectively
analyzed with respect to age, sex, clinical,
laboratory and roentgenographic features,
associated disorders and response to treatment.
A trohoc analysis lacks the accuracy and
credibility of a prospective cohort study but is less
time consuming, easier to perform and yields
almost comparable results.
A total of 843 patients with pulmonary
tuberculosis who were admitted in the wards of
the Department of Respiratory Medicine at the
Medical College, Trivandrum over a period of 5
years-1985 to 1989-formed the subject of this
study.
Results
Among the 843 admissions, a total of 20
patients (2.4%) had roentgenographic evidence
of lower lung field tuberculosis (lesions below the
hilum) : 15 were males and 5 females; 8 patients
(40%) belonged to 50-70 age group; the
commonest presenting complaint was cough with
expectoration (65%); 8 patients had cavitary and
12 (60%) non-cavitary lesions. As regards
location, 11 cases had right lung lesions while 9
had left lower lung disease (Table 1).
In all, 723 of the 843 admissions were sputum
positive (85.8%). The total comprised 65 cases
who had diabetes mellitus with 39 (60.0%) being
sputum positive and 778 non-diabetics with 684
(87.9%) being sputum positive (Table 2)
Sputum was positive for AFB in 14 patients
(70%) out of 20 with lower lung field
Table. I. Distribution of lower lung field tuberculosis
according to right or left lung and nature of
lesion as seen in x-ray
Nature of lesion
Rt.
Side of lesion
Lt. Both Total
1. Director and Professor; 2. Associate Professor; 3. Assistant Professor; 4. Post Graduate Student
From the Department of Respiratory Medicine, Medical College, Trivandrum.
Correspondence : Dr. P. Ravindran, Head, Department of Respiratory Medicine, Medical College, Trivandrum.