Diagnosis for Self-Ingestion of More Than 100 Tablets of Phenobarbital
The diagnosis is Phenobarbital Overdose (or Barbiturate Poisoning/Intoxication), which should be documented with the intentional nature of ingestion (self-ingestion/intentional overdose) and the approximate quantity ingested. 1, 2
Diagnostic Coding Considerations
Document this as "Phenobarbital Overdose" or "Barbiturate Intoxication" with notation of intentional self-harm, as this captures both the toxicological emergency and the psychiatric context that will be essential for subsequent care planning 1, 2
The ingestion of more than 100 tablets represents a massive overdose that will likely produce severe toxicity, as lethal blood levels of phenobarbital are typically greater than 80 µg/mL (usually 100-200 µg/mL), and therapeutic levels are only 5-40 µg/mL 2
Clinical Manifestations to Document
The diagnosis should be supported by documenting the expected clinical syndrome, which includes:
CNS and respiratory depression progressing potentially to Cheyne-Stokes respiration, areflexia, and coma 2
Cardiovascular manifestations including tachycardia, hypotension, and potential shock syndrome with circulatory collapse 2
Pupillary findings showing constriction to a slight degree (though severe poisoning may cause paralytic dilation) 2
Other systemic effects including oliguria, lowered body temperature, and in extreme cases, cessation of all electrical brain activity on EEG 2
Important Diagnostic Pitfalls
Barbiturate intoxication may be confused with alcoholism, bromide intoxication, and various neurological disorders, so the diagnosis must clearly state the known ingestion history to guide appropriate treatment 2
Consider co-ingestion with other CNS depressants (alcohol, opiates) as this creates additive life-threatening effects and should be documented if suspected 1
Differential diagnosis should exclude hypoglycemia, head trauma, cerebrovascular accidents, convulsive states, and diabetic coma, particularly if the history is unclear 2
Severity Indicators to Document
Document the depth of coma at presentation, as this correlates with major complications including pneumonia and cardiovascular instability 3
Note any respiratory depression requiring airway protection, as this is a critical management indicator 1
Document hemodynamic status (hypotension, shock) as this determines need for aggressive interventions including potential extracorporeal treatment 1