Comparison of two cohort of patients with severe tetanus in ICU

Introduction

Tetanus is a toxic disease produced by Clostridium tetani mostly prevented by immunization, but it is still prevalent in the Third World, has a high mortality rate and uses a high number of ICU resources. Our objective is to show our experience in two different periods managing this disease.

Methods

We compared a historical cohort of 126 patients (1981-1993) – group 1 – with a prospective cohort of 101 patients (1994–2000) – group 2, with severe tetanus. The differences between groups were: the use of lower dose of human tetanus immunoglobulin (HTIG) in group 2 (500 UI in group 2 versus 5000–7500 UI in group 1); the use of more advanced ventilators in group 2 and early physiotherapy in group 2. Both groups were compared considering: age, sex, incubation period (IP), onset period (OP), symptomatic period (SP), autonomic instability (AI), period of use of benzodiazepine (Pbenzo), curare (Pcur), mechanical ventilation (PMV), ICU stay (PICU), complications and mortality. Analysis were done with t-test for independent samples for continuous variables and chi-squared test for categorical variables. The level of significance was considered P < 0.05.

Results

Group 2 was older (49 × 39 years - P < 0.001), with less women (14/101 in group 2 × 32/126 in group 1 - P < 0.005) and presented more chronic pulmonary obstructive disease (P < 0.05) and alcoholism (P < 0.05) than group 1. There was no significant difference between groups considering other concomitant diseases (ischemic cardiopathy, diabetes mellitus, systemic arterial hypertension). Group 2 presented longer PI (P = 0.04), OP (P = 0.02), SP (P < 0.001), PICU (P < 0.001), Pbenzo (P < 0.001), Pcur (P < 0.001), and PMV (P < 0.001) than group 1. During clinical evolution, group 2 presented higher incidence of arrythmias, respiratory and urinary infections than group 1 (P < 0.001). Group 1 presented more pneumothorax and cardiopulmonary arrest (P < 0.001) than group 2, probably secondary to problems with mechanical ventilators. There were no differences between both groups regarding hypertension, hypotension and renal failure. The mortality rate was 36.5% in group 1 and 16.8% in group 2 (P < 0.005).

Conclusions

1) The reduced mortality in group 2 (P < 0.005) is probably related to advances in ICU resources (advanced ventilators and early physiotherapy). 2) The higher incidence of infections in group 2 is probably related to longer ICU stay, mechanical ventilation period and use of invasive procedures. 3) Smaller doses of HTIG (500 UI) can be safely used.