Nearly one in 100 patients admitted to hospital with Covid-19 develop a punctured lung, scientists have found.
The condition, known as pneumothorax, occurs when when air collects in the space between the lung and the chest wall.
It causes pressure on the lungs and prevents them from expanding.
Researchers believe formation of cysts in lungs could be one of the reasons why Covid-19 patients develop a punctured lung – which has previously been observed in X-rays and CT scans of those with the disease.
Symptoms of the condition include shortness of breath and sudden, sharp chest pain that is worse when taking a deep breath while coughing.
In some cases, treatment may involve draining trapped air.
Based on their findings, published in the European Respiratory Journal, the researchers say punctured lungs are a complication clinicians treating Covid-19 patients should be aware of.
Study author Professor Stefan Marciniak, from the Cambridge Institute of Medical Research, said: “Doctors need to be alert to the possibility of a punctured lung in patients with Covid-19, even in people who would not be thought to be typical at-risk patients.
“Many of the cases we reported were found incidentally – that is, their doctor had not suspected a punctured lung and the diagnosis was made by chance.”
Punctured lungs typically affect older patients with severe underlying lung disease, but being very tall can also be a risk factor for young men.
The team from the University of Cambridge and Addenbrooke’s Hospital, Cambridge University NHS Foundation Trust, looked at clinical data from 71 patients around the UK with Covid-19 who had developed a punctured lung but did not fall in either of the risk categories.
Admissions data from the 16 hospitals showed nearly 1 per cent of Covid-19 patients developed a punctured lung.
The team found that less than two-thirds (63 per cent) of patients with a punctured lung survived.
Individuals younger than 70 had a 71 per cent survival rate, compared with 42 per cent among older patients.
They also found patients with a punctured lung were three times more likely to be male than female, although the survival rate did not differ between the sexes.
Patients who had abnormally acidic blood, a condition that can result from poor lung function, also had poorer outcomes in Covid-19 pneumothorax, the researchers said.
Dr Anthony Martinelli, a respiratory doctor at Addenbrooke’s Hospital and lead author on the study, said: “Although a punctured lung is a very serious condition, Covid-19 patients younger than 70 tend to respond very well to treatment.
“Older patients or those with abnormally acidic blood are at greater risk of death and may therefore need more specialist care.”