CHENNAI: The death of an asymptomatic COVID-19 patient just a day after he was discharged from quarantine has raised a question of whether the infection is silently depleting the oxygen levels in the body tissues of the patients.
Arumugam (58), a corporation office assistant at Royapuram, was quarantined in Kilpauk Medical College (KMC) Hospital on May 18 after he tested positive. "He was completely asymptomatic for nearly 10 days, so we discharged him on May 28," said KMC dean Dr P Vasanthamani.
A day later, he collapsed and died while having dinner. Doctors suspect this could be a rare case of slow hypoxia — the lack of oxygen in body tissues — which ultimately leads to cardiac arrest and death.
When oxygen levels drop severely, people often feel breathless. However, when it is slow, people experience euphoria, confusion, and impaired psychomotor performance, almost like a sense of high. Patients are often unaware of their oxygen deprivation. "He was eating dinner with us and talking normally. Within a matter of ten minutes, he collapsed and died," said his son, who did not want to be named.
He said that Arumugam showed no symptoms at any time. "My father had no co-morbid conditions like diabetes or hypertension. He was, in fact, a hockey player," his son said. Arumugam’s daughter tested positive in the second week of May, following which samples were collected from the man.
He, however, did not go through an exit test before he was discharged from KMC. "We do not do exit test for asymptomatic or mildly symptomatic patients," Dr P Vasanthamani said.Speaking to Express, a senior government doctor handling Covid patients, on condition of anonymity, said, in rare cases, people have experienced hypoxia without realising it.
"Some people have the tendency to enjoy the confusion that comes from oxygen deprivation. They feel a certain high. If this had happened with this patient, he may not have realised that he was getting deprived of oxygen," the doctor said.
Dr Anantha Subramaniam, consultant pulmonologist from Kauvery Hospital, said that clinically a strange trend has been observed in COVID-19 patients. “Usually, there is shortness of breath when people have low oxygen supply. This is not happening in Covid patients. They don’t realise it unless oxygen level becomes really low. The mechanism is unclear,” he said.
When the normal blood oxygen saturation (SpO2) is below 94-96 per cent, people start feeling breathless. Dr Subramaniam, however, said that many patients experience breathless only when the saturation drops below 80 per cent, making it dangerous.
In a prolonged period, this may lead to a sudden cardiac arrest, says Dr Pradeep G Nayar, senior consultant cardiologist from Fortis Malar Hopital. "Heart is one of the most oxygen-demanding organ. Hypoxia can cause damage to cardiac muscle. There might be irregular electrical activity if there is prolonged Hypoxia. All this may result in a sudden cardiac arrest," he said.
Where ventilators fail to save lives
In April, an expert panel told doctors to monitor oxygen levels of all patients, including the asymptomatic. Subclinical hypoxia is a condition wherein the body is deprived of oxygen. The oxygen levels do not improve even when the patient is put on ventilator.