The phrase “First Do No Harm” is a Latin quote (Primum non nocere) often (though with little evidence) attributed to Hippocrates and applied to an historic oath for doctors. But in reality, it is virtually impossible for today’s clinicians to live by.
Why? Every cure we attempt has potential harm, every drug we give has side effects, and every procedure has risk. Perhaps a more useful principle to follow would be “the benefits outweigh the risks.” That is, for every drug we prescribe or procedure we propose, we must be clear that it is more likely to benefit rather than harm the patient.
We can tip the balance in favour of benefit by minimising risks. In drug administration this will hinge around giving the correct amount (and no more) of the right drug. In ICU sedation, propofol is the recommended first line drug world-wide, so choosing the right drug is easy. However, getting the dose right for each individual patient is more difficult. And this is where the balance between benefit and risk comes in.
Propofol, which is given by continuous infusion, is prescribed on an fixed dose basis. The only way currently that clinicians in ICU can assess the adequacy of sedation is by stopping the propofol infusion each day and waiting to see what happens – this is called sedation hold. They also regularly attempt to ‘score’ the level of sedation using subjective testing, which is, not surprisingly, known to be unreliable. There are some patients for whom neither a sedation hold nor use of a scoring system is possible. The tendency, understandably, is to give more propofol than might be needed ‘just to be sure’.
This also has risks. Propofol’s commonest side effect is to lower blood pressure. In ICU patients, blood pressure maintenance is often already an issue and giving too much propofol may require the addition of potent drugs that manage this risk by raising blood pressure. And of course, these drugs themselves carry their own risks. Patients who are over sedated in ICU spend longer on a ventilator and get more infections, especially pneumonia. Infections in critically ill patients usually require antibiotics to be given intravenously, again, drugs with potentially serious side effects.
It is easy to see how, even with the very best interests of the patient at the centre of decision making, harm builds on harm. How one drug given at an incorrect dose might require another to be added and so on.
The answer, of course, is to have a more accurate and simple way of measuring propofol to ensure more effective dosing. The introduction of propofol monitoring to help personalise dosing and reduce side effects has been described as potentially ‘game changing’. Somnus is on target to introduce ProSed®, our ICU propofol monitor, into clinical care in 2026. We have already started testing our prototype product with blood from patients.
By making propofol dosing more accurate and easier to monitor, ProSed® will reduce sedation related harm, saving lives and money in ICU.
