A recent study has found that withdrawal of Nicotine and Caffeine can cause unwanted suffering to patients in intensive care units (ICUs), leading to unnecessary laboratory testing and diagnostic imaging such as X-rays and MRIs.

The study is being discussed this year in an annual meeting, 'Euroanaesthesia' in Vienna, Austria. "Nicotine and caffeine are some of the most commonly used and highly addictive substances in modern society, but they are often overlooked as a potential source of significant withdrawal symptoms when abruptly discontinued in ICU", explains Maya Belitova, the lead researcher of the study.

Several withdrawal symptoms include nausea, vomiting, headaches, and delirium can last for up to 2 weeks. These symptoms resemble conditions such as meningitis, encephalitis, and intracranial haemorrhage--this may confuse clinical diagnosis and result in unnecessary tests which can cause discomfort to patients, shelling out a lot of money, and waste of time."

In Europe, up to 27 per cent of the population smokes and more than half drink coffee. The systematic review, synthesising all the available evidence from the scientific literature, included 12 studies investigating withdrawal symptoms and treatment in ICUs between 2000 and 2018, involving 483 adults (aged 18-93).

Results showed that acute nicotine withdrawal substantially increases agitation (64 per cent smokers vs 32 per cent non-smokers) and the number of the tracheal tube and intravenous line displacements caused by agitation in ICU patients (14 per cent smokers vs 3 per cent non-smokers).

However, nicotine substitution therapy was shown to contribute to the development of ICU delirium (severe confusion and disorientation)--which is associated with prolonged intubation, increased length of stay, and greater risk of dying. Sudden caffeine withdrawal can lead to drowsiness, nausea, vomiting, headaches, and can increase rates of ICU delirium. Caffeine benzoate has been successfully used to treat headaches but substitution in the ICU has a limited evidence base.

"ICU patients may benefit from nicotine substitution or caffeine supplementation, but with little evidence for their effectiveness, this should be left up to the judgement of treating physicians", said Belitova.

"There is a lack of evidence on abrupt caffeine withdrawal, its complications and therapeutic options. Future research should focus on acute caffeine withdrawal as an independent risk factor for agitation and delirium in ICU and on available treatment options," she added.