Cholinergic crisis

While die patient is receiving a cholinergic drug it is important for the nurse to monitor for drug toxicity or cholinergic crisis. 

Fenthion has also exhibited delayed neurotoxicity in which the initial cholinergic crisis was delayed 5 days and recurred 24 days after ingestion. Psychosis was a persistent manifestation. Because of the high lipid solubility of fenthion, toxin analysis of repeated fat biopsies was an essential component of patient management. ... 

The pronounced weakness that may result from inadequate therapy of myasthenia gravis (myasthenic crisis) can be distinguished from that due to anticholinesterase overdose (cholinergic crisis) by the use of edrophonium. In cholinergic crisis, edrophonium will briefly cause a further weakening of muscles, whereas improvement in muscle strength is seen in the... 

Overdosage may result in cholinergic crisis, characterized by severe nausea, vomiting, diarrhea, increased salivation, diaphoresis, bradycardia, hypotension, flushed skin, stomach pain, respiratory depression, seizures, and paralysis of muscles. 

Symptoms of increasing muscle weakness may be due to cholinergic crisis (overdosage) or myasthenic crisis (increased disease severity) if crisis is myasthenia, patient will improve after 1-2 mg edrophonium if cholinergic, withdraw am-benonium and administer atropine... 

Overdosage causes symptoms of cholinergic crisis such as muscle weakness, nausea, vomiting, miosis, bronchospasm, and respiratory paralysis. 

Since symptoms of anticholinesterase overdose (cholinergic crisis) may mimic underdosage (myasthenic weakness), their condition may be worsened by the use of this drug... 

Overdose may cause cholinergic crisis, characterized by increased salivation, lacri-mation, severe nausea and vomiting, bradycardia, respiratory depression, hypotension, and increased muscle weakness. Treatment usually consists of supportive measures and an anf icholinergic such as afropine. 

Overdose produces a cholinergic crisis manifested as abdominal discomfort or cramps, nausea, vomiting, diarrhea, flushing, facial warmth, excessive salivation, diaphoresis, lacrimation, pallor, bradycardia or tachycardia, hypotension, bron-chospasm, urinary urgency, blurred vision, miosis, and fasciculation (involuntary muscular contractions visible under the skin). 

These patients may also exhibit symptoms of excessive stimulation of muscarinic receptors (abdominal cramps, diarrhea, increased salivation, excessive bronchial secretions, miosis, bradycardia). Small doses of edrophonium (1-2 mg intravenously) will produce no relief or even worsen weakness if the patient is receiving excessive cholinesterase inhibitor therapy. On the other hand, if the patient improves with edrophonium, an increase in cholinesterase inhibitor dosage may be indicated. Clinical situations in which severe myasthenia (myasthenic crisis) must be distinguished from excessive drug therapy (cholinergic crisis) usually occur in very ill myasthenic patients and must be managed in hospital with adequate emergency support systems (eg, mechanical ventilators) available. 

THA overdosage can result in a cholinergic crisis with severe nausea, vomiting, salivation, sweating, bradycardia, hypotension, convulsions, etc. Progressive muscle weakness may result in death from asphyxiation. Treatment with anticholinergics (such as intravenous atropine sulfate) and general supportive treatment are recommended. 

Severe OP-poisoning is evidenced by the rapid onset of unconsciousness, local or generalized seizures, incontinence and other manifestations of a cholinergic crisis. Further indications of severe intoxication may include a slow heartbeat, tearing, toxic psychosis... 

The actions of edrophonium [ed roe FOE nee um] are similar to those of neostigmine, except that it is more rapidly absorbed and has a short duration of action (10-20 minutes). Edrophonium is a quarternary amine and is used in the diagnosis of myasthenia gravis. Intravenous injection of edrophonium leads to a rapid increase in muscle strength. Care must be taken since excess drug may provoke a cholinergic crisis. Atropine is the antidote. 

Nicotinic symptoms may be observed initially, but muscarinic signs can be observed concurrently. Later in the course of poisoning, muscarinic signs predominate. Persistent depolarizing neuromuscular blockade may develop after initial resolution of the cholinergic crisis and can cause sudden respiratory failure and death (Reutter, 1999 Weinstein Alibek, 2003). Initial patient diagnoses and treatments are likely to be based on observations of signs and symptoms by the paramedic or other health care professionals at the scene (Table 25.3). Rescuers and health care workers must prevent direct... 

Cowan, F.M., Shih, T.M., Lenz, D.E., Madsen, J.M., Broomfield, C.A. (1996). H pothesis for synergistic toxicity of organo-phosphorus poisoning-induced cholinergic crisis and anaphylactoid reactions. J. Appl. Toxicol. 16 25-33. 

FIGURE 61.3. Helpful mnemonic for cholinergic crisis (BAG the PUDDLES). Illustrations are copyright protected and printed with permission hy Alexandre M. Katos (Rotenherg and Newmark, 2003). 

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