Dengue Fever - Clinical and Laboratory Parameters Associated with Complications

This study was conducted on seropositive cases of dengue less than 12 years of age admitted in a tertiary-level referral centre during the outbreak of dengue in Chennai, India, between October and December 2001. Fifty-nine cases were admitted during the study period and detailed clinical history, physical examination and laboratory values were recorded on presentation. The cases were followed-up daily for the clinical and laboratory parameters. These children were stratified based on the presence or absence of complications like shock and haemorrhage. The frequency of various signs and symptoms and the values of laboratory tests were compared between the children with and without complications. The proportions were statistically analysed and the odds ratio for the development of complications based on the presence of each parameter was computed. Sixteen clinical features and eight laboratory investigations were analysed in these patients. The factors related to shock were drowsiness (p=0.0002), positive tourniquet test (p=0.0004), low platelet count (p=0.005) and raised renal parameters (p=0.002). Parameters associated with bleeding manifestations were retro-orbital pain (p=0.006), more hepatomegaly (p=0.002) and low platelet count (p=0.045). Fall of haematocrit by more than 20% on fluid therapy was slightly more in the bleeding group (p=0.07). There was no correlation between tourniquet test positivity and other bleeding manifestations. Bleeding was related to very low platelet counts (<50,000). However, moderately low platelet counts (50,000-100,000/cu.mm) were not associated with increase in the frequency of bleeding manifestations. Patients who did not develop shock were more likely to complain of body pain (p=0.07). These results showed that children with dengue who present with drowsiness, retro-orbital pain, positive tourniquet test, platelet counts below 50,000/cu.mm and a fall of haematocrit on therapy by more than 20% and those who do not have body pain should be monitored very carefully, as they are more prone to develop complications. KEYWORDS: Dengue, complications, associations, Chennai.