Kent R. Olson, MD
The first priority in the poisoned patient is to assure a patent airway and adequate breathing. Respiratory arrest and pulmonary aspiration are two common complications of depressed mental status that can lead to serious morbidity or death.
The airway may be obstructed by a floppy tongue or by secretions or vomitus. Position the patient to enhance patency by slightly tilting the head backward (extension of the neck) while lifting the head forward relative to the chest (the “sniffing position”). Or, lift the chin forward by placing your fingers behind the angle of the jaw on each side - this lifts the tongue forward, relieving obstruction, and it often provides an uncomfortable stimulus that may awaken the mildly intoxicated patient.
Figures 1 and 2. Airway obstruction in supine positing, and Head tilt
Figure 3. Jaw thrust
Endotracheal intubation: If it is obvious that the airway reflexes are impaired (deep coma, no gag or cough reflex) then the patient will need to be intubated endotracheally. This is usually performed via the orotracheal route, although if the patient is breathing spontaneously the nasotracheal route can be used. Rapid sequence intubation (RSI) is a standardized procedure that includes pre-oxygenation, administration of sedative-hypnotic drugs (e.g., midazolam, etomidate) and muscle relaxants (e.g., succinylcholine, rocuronium) in conjunction with orotracheal intubation. After intubation, a rapid assessment is needed to assure that the endotracheal tube is in the trachea and not the esophagus. This is done by listening over the lungs and stomach, watching for chest rise with ventilation, and use of a carbon dioxide detector on the end of the ET tube. Looking for condensation in the ET tube is also helpful.
If the patient is breathing spontaneously and appears to have satisfactory airway protective reflexes, determine the adequacy of minute ventilation. This can be done by direct observation of the rise and fall of the chest, the measured rate of breathing, and noting a pink color to the mucous membranes indicating oxygenation. Arterial blood gases are definitive but not always readily available and frequently not needed. Pulse oximetry gives an estimate of oxygenation which can be reassuring in the patient who also appears to be ventilating adequately by visual inspection.
Most patients with acute poisoning causing CNS depression can be satisfactorily managed with good supportive care, including airway positioning and assisted ventilation. Some patients will also have depression of their cardiovascular tone, and may need IV fluids or vasopressors.
Start at least one intravenous line, and draw some blood for routine testing (e.g., complete blood count, electrolytes, BUN and creatinine, glucose, liver enzymes, and acetaminophen level). Place the patient on a cardiac monitor, if available, and determinethe rate and rhythm of cardiac activity. Measure the blood pressure.