Severity of respiratory illness predicts early death of Covid patient, not comorbidity — study

The IJMR study shows that the severity of respiratory illness, blood parameters and lactate levels predicted early death of Covid-19 patients within 24 hours.

A woman is tested for Covid-19 in Bengaluru | Representational image | PTI file photo

New Delhi: Severity of respiratory illness and parameters of blood predict the early death of Covid-19 patients rather than age or presence of comorbidity, found a study published by the IJMR (Indian Journal of Medical Research).

The study, titled ‘Epidemiological and Clinical Characteristics & Early Outcome of Covid-19 patients in a Tertiary Care Teaching Hospital in India: A Preliminary Analysis’, has been written by 13 authors working in the Department of Anesthesiology, Pain Medicine and Critical Care of All India Institute of Medical Sciences (AIIMS), Delhi.

In the study, all adult patients admitted to the screening intensive care unit (ICU) of  AIIMS who fulfilled the WHO case definition of Covid-19 and confirmed to have the disease using reverse transcription-polymerase chain reaction (RT-PCR) test were included.

Published on 18 August, the study found that nearly half of the patients were presented with “severe and critical disease” and they required “high-flow nasal oxygen or invasive mechanical ventilation at admission”. 

However, the severity of their respiratory illness, haematological parameters (related to blood) and lactate rather than age or presence of comorbidity predicted early death within 24 hours, the study stated.

The parameter of lactate shows the disruption in the person’s acid-base (pH) balance caused by an inadequate amount of oxygen in cells and tissues. The higher level of lactate indicates that organs are not functioning properly. 

How the study was conducted? 

The study was conducted on 235 patients, with 68 per cent being male. 

The most common symptoms, according to the study, were fever (68.1 per cent), cough (59.6 per cent) and shortness of breath (71.9 per cent). Hypertension (28.1 per cent) and diabetes mellitus (23.3 per cent) were the most common associated comorbid illnesses.

“The 24 hours ICU mortality was 8.5 per cent, and non-survivors had higher respiratory rate and lower baseline oxyhaemoglobin saturation at presentation and higher baseline serum lactate, total leucocyte count, absolute neutrophil count, prothrombin time and INR compared to survivors,” said the study.

Prothrombin time and INR are the tests that measure how much time it takes for a patient’s blood to clot whereas higher total leucocyte count and  absolute neutrophil count show presence of infection in the body.

Oxyhemoglobin is a “measure of how much of the oxygen-carrying capacity due to hemoglobin is being utilised”.