Management of Paraquat Poisoning with Respiratory Failure, Chills, and Rigors
The most effective treatment for paraquat poisoning with respiratory failure, chills, and rigors includes immediate decontamination, restricted oxygen therapy (target saturation 85-88%), combined immunosuppressive therapy with methylprednisolone, cyclophosphamide, and dexamethasone, along with early hemoperfusion within 2-4 hours of ingestion.
Initial Management and Decontamination
- Remove all contaminated clothing and perform thorough skin decontamination with soap and water 1
- Healthcare providers must wear appropriate protective equipment (gloves) to prevent secondary exposure 1
- If within 1-2 hours of ingestion, consider gastric lavage to reduce absorption 1
- Administer activated charcoal to bind any remaining toxin in the gastrointestinal tract 1
Respiratory Management
- Restrict supplemental oxygen to target saturation of 85-88% - this is critical as excessive oxygen worsens paraquat-induced lung injury through enhanced free radical production 1
- Only provide oxygen when saturation falls below 85% to minimize further lung damage 1
- Avoid mechanical ventilation with high oxygen concentrations when possible 1
- If intubation is necessary for airway protection:
- Use the lowest possible FiO2 settings
- Consider permissive hypoxemia strategy
- Monitor closely for signs of worsening respiratory failure
Immunosuppressive Therapy
- Implement combined immunosuppressive therapy immediately 1, 2:
- This regimen has shown improved survival rates compared to supportive care alone 2
- The combination of methylprednisolone, cyclophosphamide, and dexamethasone is associated with the highest survival rate (48%) 2
Extracorporeal Elimination
- Initiate hemoperfusion with activated charcoal within 2-4 hours of ingestion 1
- Do not delay hemoperfusion as efficacy decreases significantly after the first 4 hours post-ingestion 1
- Consider continuous kidney replacement therapy (CKRT) for patients with severe renal impairment 1
Antioxidant Therapy
- Administer N-acetylcysteine (300 mg/kg/day for up to 3 weeks) to reduce oxidative stress 1
- Consider other antioxidants to combat free radical damage
Management of Chills and Rigors
- Provide antipyretics for fever control
- Consider benzodiazepines for severe rigors
- Maintain normothermia with warming or cooling measures as needed
- Monitor for signs of infection, as chills and rigors may indicate secondary infection
Renal Management
- Monitor renal function closely as acute kidney injury occurs in approximately 50% of cases 1
- Provide appropriate fluid management and diuresis 1
- Initiate renal replacement therapy if indicated by severe renal failure 3
- Watch for non-oliguric renal failure 1
Monitoring and Supportive Care
- Continuously monitor:
- Respiratory status (work of breathing, respiratory rate, oxygen saturation)
- Renal function (urine output, creatinine, BUN)
- Hepatic function (liver enzymes, bilirubin)
- Acid-base balance
- Manage fluid and electrolyte imbalances
- Provide nutritional support
- Prevent complications of critical illness (DVT prophylaxis, stress ulcer prevention)
Prognosis
- Plasma paraquat concentrations and urine dithionite tests are important prognostic indicators 1
- Absence of caustic burns in the upper digestive tract indicates a better prognosis 4
- Patients younger than 45 years have better outcomes with immunosuppressive therapy (41% vs 33.7% survival) 2
- Overall mortality remains high despite treatment, with survival rates around 26.4% 2