When a loud noise means big trouble

Of all the problems a hospital doctor can be called about in the middle of the night, stridor is one of the scariest. It’s a sound anyone can recognise – a high-pitched, grating rasp, accompanied in films by the affected person clutching their throat and staggering sideways. It’s a noise you can’t ignore.

We’d admitted Mr R earlier in the day with tonsillitis. His tonsils were so enlarged and tender that he couldn’t swallow liquids, and so he’d been admitted for fluids and antibiotics. He wasn’t the most appealing patient: he’d refused to change into a gown, preferring to lounge on his bed in a pair of Y-fronts and an Iron Maiden T-shirt, and he’d upset the nurses by addressing them as “Babycakes”. When we’d admitted him, he’d exhaled luxuriantly into my colleague’s face and said “Bet that doesn’t smell too hot, does it?”. “I’m not getting meadows,” my colleague agreed.

His petulance had made him hard to examine – he undoubtedly had some trismus (spasm of the jaw muscles, which makes it hard to open your mouth), but he’d exaggerated it, presenting us with a mouth pursed like a goldfish’s when asked to open wide. Now, at 3am, things were more serious. Coming to the dark ward, it was obvious something was wrong. Mr R’s light was on; his curtains were drawn and bulging with nurses. The patients on either side were awake, sitting up in their covers and holding their phones.

Mr R’s stridor was audible from the door. Unlike many signs in medicine, stridor sends an unambiguous message. It tells you that your airway is becoming obstructed; that is, your windpipe is becoming blocked. Each scraping inhalation measures progress towards an even more frightening noise: silence.

The gasping tells you your patient is still breathing, at least. And while he is, you need to assess him. You can’t just jump to treatment. You have to bend in under the patient’s panicky face to put your stethoscope on his chest, take his pulse and feel his calves to check for deep vein thrombosis.

Mr R’s pulse was racing; his fingertips were turning blue. The most obvious thing was his head, which seemed to have developed instant mumps: his neck had swollen grotesquely. I went to the desk and phoned the registrar. Mr R was in theatre within half an hour; he needed a tracheostomy.

Anything that obstructs your airway can cause stridor. It may be an object from outside – a peanut, a lost filling. It could be the result of something inside: a tumour blocking your bronchus, tissues swollen by an anaphylactic reaction or an infection, such as croup. Contrary to frequent patient belief, simple tonsillitis almost never causes stridor in adults: your throat is unlikely to “swell shut”, as one patient told me hers was doing, although it may feel that way.

Mr R’s tonsils were a decoy; his fetid breath was a better lead. He’d developed a condition called Ludwig’s angina (named after the German doctor who first identified it, and nothing to do with heart disease – the “angina” here just means “strangling”). Ludwig’s angina is an infection of the floor of the mouth, beneath the tongue. As it progresses, the tissues swell, pushing the tongue up and blocking the passage of air. The bacteria often track from an infected molar; as our teeth have improved, so Ludwig’s angina has largely vanished in Britain. Mr R needed surgery to drain the infection. Back on the ward, he was very quiet ...

Sophie Harrison is a hospital doctor in South Yorkshire. Some details have been changed in the interest of confidentiality