Table 2.
Clinical Management of Organophosphorus-poisoned Patients
| Intervention | Comment | Time Point |
|---|---|---|
| Maintain airway and provide adequate oxygenation (>85% saturations) | Quick and efficient securing of the airway. Note: the depolarizing neuromuscular blocker suxamethonium will have a prolonged effect (up to 12 h) due to acetylcholinesterase inhibition. Avoid where possible (25, 112, 113). | Within minutes after nerve agent poisoning, within minutes to hours after insecticide poisoning to avoid hypoxic brain damage |
| Administer escalating dose atropine regimen | Give intravenous atropine (initially 0.6–3 mg, doubling every 5 min until muscarinic features start to subside). This will help maintain patient oxygenation and lessen the risk of aspiration injury. Infusions of atropine may be required for many days; titrate to effect (93, 94). Do not delay if oxygen is not immediately available (92). | Within minutes after nerve agent poisoning, within minutes to hours after insecticide poisoning to avoid hypoxic brain damage |
| Administer benzodiazepines | Give diazepam 10–20 mg or lorazepam 2–4 mg to control seizure activity and agitation, and to sedate intubated patients. | Minutes to hours |
| Administer oximes | Give 1 g pralidoxime or 250 mg obidoxime, then an infusion. Oximes are not of proven clinical benefit but can be considered in patients presenting early. Patients should be weaned when possible, preferably guided by neurophysiological studies. | Hours to days |
| Ventilation strategy | Use protective ventilation (6 ml/kg); avoid plateau pressures >30 cm H2O. | For the duration of ICU stay; days to weeks |
| Response to NDMRs may be unpredictable (25, 114). Titrate dose to effect. | As required for intubation and ventilation. | |
| Use of aminosteroid NMBAs (e.g., rocuronium) may provide some protection of nicotinic receptors. | ||
| Cardiovascular instability | Dysrhythmias and severe hypotension can occur in OP poisoning and are treated by standard ICU practices (53). Note: effects of drugs that are metabolized by plasma cholinesterase (BuChE) (e.g. esmolol, may prolonged in OP poisoning). | Hours to days |
| Prevention of VAP | Provide VAP prevention strategies: sit the patient at 30–45°, consider selective digestive and/or oropharyngeal decontamination (66), start antibiotics (after consultation with a local microbiologist) only if bronchopneumonia or sepsis is suspected (64). | Hours to days |
| Inhaled β-agonists, anticholinergics | Standard therapy for many critical care units. Observe for tachyarrhythmias when combined with intravenous atropine. | For the duration of ICU stay; days to weeks |
| Prevention of CIP/CIM | Wean as early as possible from the ventilator to reduce the risk of CIP/CIM. | >7 d to weeks |
| ICU sedation | Minimal sedation and daily sedation holds as per VAP prevention strategies and staffing levels allow (64). This will allow early identification of the return of consciousness in poisoned patients who can then be weaned from the ventilator. | For the duration of ICU stay; days to weeks |
| Standard ICU care to improve survival of patients with ARDS | GI ulceration care, nutrition, thrombosis prophylaxis, timely antibiotics for infections, judicious intravenous fluid management and lung protective ventilation strategies (115). | For the duration of ICU stay; days to weeks |
| Careful observation | Careful observation of patients with OP insecticide poisoning will identify cholinergic features, labored respiratory efforts, and proximal muscle weakness heralding the onset of IMS or delayed cholinergic effects. | Hours to days after poisoning and after extubation |
| Extubation | Requires several hours of successful spontaneous ventilation and the ability to lift their head off the bed on at least three different time points before a trial of extubation should be attempted (96). | Hours to days |
| If prolonged ventilation is anticipated, consider tracheostomy. Be aware of laryngeal muscle dysfunction. |
Definition of abbreviations: ARDS = acute respiratory distress syndrome; BuChE = butyrylcholinesterase; CIP = critical illness polyneuropathy; CIM = critical illness myopathy; GI = gastrointestinal; ICU = intensive care unit; IMS = intermediate syndrome; NDMRs = nondepolarizing muscle relaxants; NMBA = neuromuscular blocking agent; OP = organophosphate; VAP = ventilator-associated pneumonia.