Toxicology Case Study: Acetaminophen Poisoning
\nHistory: A 20-year-old female presents to the Emergency Department after
\ningesting over 50 tablets of Tylenol Extra Strength\u00ae eight hours prior to
\narrival in a suicide attempt. She denies coingestants and complains of
\nnausea.
\nPMH: None.
\nPhysical Examination:
\nT: 99 \u00b0F HR: 90 bpm RR: 12 breaths per minute BP: 120\/72 mm Hg
\nGeneral: Tearful female in no acute distress.
\nHEENT: Pupils 4 mm and reactive, moist mucus membranes.
\nPulmonary: Clear to auscultation.
\nCV: Tachycardic with regular rhythm.
\nAbdomen: Normal bowel sounds, nontender to palpation.
\nNeurologic: Unremarkable.<\/p>\n
Pharmacology Case Study Questions
\n1. What is the most important historical information that should be obtained?
\n2. What diagnostic testing, if any, would you perform?
\n3. What treatment, if any, should be initiated immediately?
\n4. What is the appropriate disposition of this patient?
\n5. Explain the mechanism of toxicity of acetaminophen. <\/p>\n
Case Study: Acetaminophen Poisoning
\n1. The presence of coingestants and confirmation of the time of ingestion is the most
\nimportant historical information to obtain. The time of ingestion should be
\ndetermined so that accurate plotting of the level on the Rumack-Matthew
\nnomogram can be accomplished to determine the risk of toxicity. Tylenol Extra
\nStrength\u00ae contains 500 mg of acetaminophen (APAP) per tablet; however there is
\nno reliable way to predict toxicity based on the patient\u2019s report of the quantity
\ningested.
\n2. The only initial laboratory tests that should be obtained are a serum APAP level
\nand a pregnancy test. Because the Rumack-Matthew nomogram does not risk
\nstratify patients based on levels obtained prior to four hours after ingestion,
\nobtaining acetaminophen levels prior to this time is not useful except possibly to
\nsubstantiate a claim of overdose. One may consider ordering baseline LFTs and
\nPT\/PTT if the APAP level is in the toxic range, but this early after the ingestion,
\none would expect those to be normal if the patient has no underlying disease. A
\ntoxicology screen would not be useful because the patient is relatively
\nasymptomatic and has a normal exam.
\n3. Because the ingestion occurred eight hours earlier, N-acetylcysteine (loading dose
\n140 mg\/kg) should be administered prior to the laboratory results. The antidote is
\nmost effective if administered within the first 8-10 hours. If the level is non-toxic,
\nfurther doses are not indicated. If the patient presents prior to the eight hour
\nmark, there is no known advantage to administering NAC before the level returns.
\nIn this patient, the eight hour level is 250 mcg\/ml.
\n4. Because the patient\u2019s eight hour acetaminophen level places her in the \u201cprobable
\nhepatotoxicity\u201d category, she should be admitted for the full course of NAC.
\nSuicide precautions should be continued as an inpatient.
\n5. Hepatic metabolism of acetaminophen occurs via the cytochrome p450 system
\nand produces a highly reactive metabolite called N-acetyl-p-benzoquinone imine,
\n(NAPQI). In therapeutic doses, approximately 4% of APAP is metabolized via the
\nP450 system and the resultant NAPQI is detoxified by the glutathione stores in the
\nliver. In the presence of toxic doses, the amount of acetaminophen metabolized
\nby the cytochrome p450 system increases, subsequently depleting glutathione
\nstores and leading to an increased amount of NAPQI. NAPQI acts to cause
\ntoxicity by binding to the hepatocyte and resulting in cell death.<\/p>\n","protected":false},"excerpt":{"rendered":"
Toxicology Case Study: Acetaminophen Poisoning History: A 20-year-old female presents to the Emergency Department after ingesting over 50 tablets of Tylenol Extra Strength\u00ae eight hours prior to arrival in a suicide attempt. She denies coingestants and complains of nausea. PMH: None. Physical Examination: T: 99 \u00b0F HR: 90 bpm RR: 12 breaths per minute BP: […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1296,1560,1363,627,985,279,1660],"tags":[1658,1657,1247,1659],"class_list":["post-5218","post","type-post","status-publish","format-standard","hentry","category-pharmacology-toxicology-case-study-assignment-help","category-case-study-research-writing-and-analysis","category-health-nursing-case-study-homework-help","category-how-to-write-a-case-study-examples-assignments","category-pharmacokinetics-and-pharmacodynamics","category-pharmacology","category-toxicology-assignment-help","tag-acetaminophen-toxicity","tag-n-acetylcysteine-nac-treatment","tag-nursing-papers","tag-suicide-attempt"],"_links":{"self":[{"href":"https:\/\/www.colapapers.com\/nursing\/wp-json\/wp\/v2\/posts\/5218","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.colapapers.com\/nursing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.colapapers.com\/nursing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.colapapers.com\/nursing\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.colapapers.com\/nursing\/wp-json\/wp\/v2\/comments?post=5218"}],"version-history":[{"count":1,"href":"https:\/\/www.colapapers.com\/nursing\/wp-json\/wp\/v2\/posts\/5218\/revisions"}],"predecessor-version":[{"id":5219,"href":"https:\/\/www.colapapers.com\/nursing\/wp-json\/wp\/v2\/posts\/5218\/revisions\/5219"}],"wp:attachment":[{"href":"https:\/\/www.colapapers.com\/nursing\/wp-json\/wp\/v2\/media?parent=5218"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.colapapers.com\/nursing\/wp-json\/wp\/v2\/categories?post=5218"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.colapapers.com\/nursing\/wp-json\/wp\/v2\/tags?post=5218"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}