NIV of comatose patients with acute poisoning: The NICO Trial

The CASE 

A 28 yo patient is brought in by ambulance with a depressed conscious state. The ambulance was called by friends who give a history of the patient drinking all night. There is no known other substances.

On arrival:

• GCS 8
• Afebrile
• HR 98bpm,
• BP 136/62
• Saturations 97% on room air.

 Would you intubate this patient?

What if the GCS was 5 or 6?

In days gone by, due to the depressed conscious state and the uncertainty of other substances, we would, in most cases opt for intubating this patient, to secure the airway avoiding the risks of aspiration. Should we? Are creating more potential problems?

I must admit that in pure intoxication, if the patient can be nursed appropriately(resource problem), I would hold off on intubation. However if there was any other substance involved, or there was a risk of intracranial injury (which is difficult to pick), I would intubate.

Along comes the NICO Trial (1) (Non-invasive Airway Management of Comatose Poisoned Emergency Patients).

 Question They Asked

“In patients with suspected poisoning and Glasgow Coma Scale score less than 9, is a conservative airway strategy of withholding intubation associated with a reduction of death, intensive care unit length of stay, and hospital length of stay compared with routine practice?”

 What They Did

This was a multicentre study(20 Emergency Departments and 1 ICU in France), Randomised Trial.

N= 225

The study was not blinded and the need for intubation in the conservative group was left to the clinician’s judgement.

Patients that were excluded included:

• Pregnant patients
• Those that were Involuntarily detained
• Patients that required immediate airway control (ie., these patients were intubated) which included:
  • Patients in respiratory distress
  • When there was a suspicion of brain injury
  • If the patient had a seizure
  • If they were in a shock state.
• Patients that had overdoses on a cardiac drug, including beta blockers, Calcium Channel Blockers or ACE Inhibitors.
• Patients that had taken a reversible toxin eg opioids.

Primary Outcome:

They looked at an end point of in-hospital death, length of ICU stay, and length of hospital stay.

Secondary Outcomes:

Adverse events from intubation and pneumonia within 48 hours.

What They Found:

• There were no in hospital deaths in both groups.
• There was a decrease in Median ICU and Hospital Stay
• The rate of occurrence of pneumonia was less in the conservative group 8 (6.9%) and 16 (14.7%) patients, respectively (absolute risk difference, −7.8% [95% CI, −15.9% to 0.3%]) This means that NNT is 13.
• The adverse effects of intubation were less in the conservative group (6% vs 14.7%; absolute risk difference, 8.6% [95% CI, −16.6%

Conclusion by the authors.

“Among comatose patients with suspected acute poisoning, a conservative strategy of withholding intubation was associated with a greater clinical benefit for the composite end point of in-hospital death, length of ICU stay, and length of hospital stay.”

My Take on This and Will it Change my Practice?

A few things to comment on:

• Nearly 70% of all the patients had alcohol intoxication ie., no other drugs were involved. 
• No activated charcoal was given in any cases. That probably makes sense given that most patients had alcohol intoxication.
• In patients that had taken other substances, most of the toxins ingested had a short half life. We are therefore unsure if the same would occur if longer acting toxins were taken.

This study tells me is that certainly in alcohol intoxication, a conservative strategy( ie., no intubation) may be best. However other forms of poisoning I’m still not sure about. For short acting toxins, we can perhaps, use the same conservative strategy.

References

1. Freund Y et al. Effect of Noninvasive Airway management of Comatose Patients with Acute Poisoning: A Randomized Clinical Trial.   2023;330(23):2267-2274. PMID: 38019968