Rosen & Barkin's 5-Minute Emergency Medicine Consult (68 page)

• Ampicillin/sulbactam: 3 g (peds: 100–200 mg ampicillin/kg/24 h) IV q6h
  
• Cefoxitin: 2 g (peds: 80–100 mg/kg/24 h) IV q6h
  
• Ceftriaxone: 1 g (peds: 50–100 mg/kg) IV q24h
  
• Ciprofloxacin: 400 mg (peds: 20–40 mg/kg) IV q12h
  
• Ertapenem: 1 g IM/IV q24h
  
• Metronidazole: 500 mg (peds: 30–50 mg/kg/24 h) IV q8–12h
  
• Morphine sulfate: 3–5 mg (peds: 0.1–0.2 mg/kg per dose q2–q4h) IV, every 15 min titrated to effect
  
• Piperacillin/tazobactam: 3.375 g (peds: 150–300 mg/kg/d if <6 mo; 240–400 mg/kg/d if >6 mo) IV q6h
  

FOLLOW-UP

• Surgical intervention of acute appendicitis
  
• Observation or further diagnostic workup if diagnosis is uncertain
  

Patients with abdominal pain thought not to be appendicitis may be discharged if they meet the following criteria:

• Resolved or resolving symptoms
  
• Minimal or no abdominal tenderness
  
• No lab/radiologic abnormalities
  
• Able to tolerate PO intake
  
• Adequate social support and able to return if symptoms worsen
  

24–48 hr recheck for patients discharged from the ED with abdominal pain of unclear etiology

• Pediatric and geriatric patients present atypically and have increased perforation rates
  
• Imaging is not required in a classic presentation of acute appendicitis
  
• Appendicitis cannot be ruled out on any imaging modality if the appendix is not visualized
  

• Basaran A, Basaran M. Diagnosis of acute appendicitis during pregnancy: A systematic review.
  Obstet Gynecol Surv
  . 2009;64(7):481–488.
  
• Hennelly KE, Bachur R. Appendicitis update.
  Curr Opin Pediatr
  . 2011;23:281–285.
  
• Long SS, Long C, Lai H, et al. Imaging strategies for the right lower quadrant pain in pregnancy.
  AJR Am J Roentgenol
  . 2011;196:4–12.
  
• Singh A, Danrad R, Hahn PF, et al. MR imaging of the acute abdomen and pelvis: Acute appendicitis and beyond.
  Radiographics
  . 2007;27:1419–1431.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Abdominal Pain
  
• Vomiting, Adult; Vomiting, Pediatric
  

CODES

• 540.1 Acute appendicitis with peritoneal abscess
  
• 540.9 Acute appendicitis without mention of peritonitis
  
• 541 Appendicitis, unqualified
  

BASICS

• Acute toxicity:
  
  • Caused by intentional ingestion, malicious poisoning, or medication error
    
• Minimal lethal ingested dose ∼2 mg/kg
  
• Chronic toxicity:
  
  • Resulting from occupational exposures, water or food contamination, or use of folk remedies containing arsenic
    
• Ingestion is the primary route of exposure
  
• Inhalational toxicity is possible from arsine gas exposure
  

• Most cases seen in the ED result from intentional ingestion or malicious poisoning
  
• Sodium arsenate, found in ant killer, is the most common acute exposure in the US
  
• Contaminated food and water supplies are the most common cause worldwide
  
• Inorganic arsenic trioxide has been recently approved as a chemotherapeutic agent for acute myelogenous leukemia (AML)
  
• Melarsoprol, an organic arsenical, has been used to treat trypanosomiasis since 1949
  
• Found in pesticides, certain folk remedies (herbal balls), industrial wood preservatives
  
• May be released as arsine gas from combustion of zinc- and arsenic-containing compounds
  

• Arsenic exists in several forms—gas (arsine, or lewisite), organic, elemental, and inorganic
  
• Inorganic forms (pentavalent and trivalent arsenic) are most frequently involved in toxic exposures:
  
  • Pentavalent arsenic uncouples oxidative phosphorylation
    
  • Most pentavalent arsenic is converted to the more toxic trivalent arsenic in the body
    
  • Trivalent arsenic binds sulfhydryl groups and interferes in hemoglobin production
    
  • Some trivalent arsenic may be methylated into species of varying toxicity
    
  • The more reactive species are DNA damaging and genotoxic
    

DIAGNOSIS

• CNS:
  
  • Altered mental status/encephalopathy
    
  • Neurodevelopmental deficits in children
    
  • Peripheral neuropathy
    
    • Acute: Sensory neuropathy
      
    • Subacute: Sensorimotor neuropathy
      
  • Peripheral dysesthesias
    
  • Headache
    
  • Seizures
    
• Cardiovascular:
  
  • Prolonged QTc interval
    
  • Hypotension (acute) or hypertension (chronic)
    
  • Dysrhythmias, primarily ventricular
    
  • Nonspecific ST segment changes
    
  • Noncardiogenic pulmonary edema
    
• Pulmonary:
  
  • Inhalational exposure increases lung cancer risk and respiratory mortality
    
  • Large acute ingestion (8 mg/kg) may lead to severe respiratory distress
    
    • Pulmonary edema, hemorrhagic bronchitis, and bronchopneumonia
      
• GI:
  
  • Nausea, vomiting after ingestion and possibly inhalation
    
    • Protracted and may be refractory to antiemetics at usual doses
      
    • Can have hemorrhagic gastroenteritis; corrosive to GI tract
      
  • Rice water diarrhea
    
  • Abdominal pain
    
  • Garlic odor to breath, vomit, stools
    
  • Causes acute hepatitis; chronically, can cause portal HTN
    
  • A possible association with diabetes mellitus in chronic exposure
    
• Miscellaneous (usually associated with chronic exposure)
  
  • Acute rhabdomyolysis
    
  • Blackfoot disease in Taiwan: Gangrene from loss of circulation to extremities
    
  • Dermatitis, such as toxic erythroderma and hyperkeratotic, hyperpigmented lesions
    
  • Hemolytic anemia (more pronounced with arsine gas exposure)
    
  • Hypothyroidism (antagonizes thyroid hormone)
    
  • Increased risk of carcinoma (liver/basal cell/squamous cell of skin/bronchogenic)
    
  • Leukopenia (after several days)
    
  • Mees lines (white bands across the nails owing to growth arrest caused by arsenic)
    
  • Patchy alopecia
    
  • Raynaud phenomenon and vasospasticity
    

• Spot urine arsenic level
  
• CBC
  

• Spot urine arsenic level >1,000 μg/L may confirm diagnostic suspicion:
  
  • Peaks 10–50 hr postingestion
    
• Definitive test is 24 hr urine collection with speciation into organic and inorganic types of arsenic.
  
• Blood levels not routinely helpful owing to short half-life in serum (∼2 hr)
  
• CBC to evaluate for anemia, leukopenia, basophilic stippling
  
• Electrolytes, BUN/creatinine, and glucose
  
• Urinalysis to look for evidence of hemolysis/rhabdomyolysis
  
• Liver function tests
  
• Total creatine phosphokinase (CPK) for rhabdomyolysis
  
• Hair and nail arsenic levels:
  
  • Do not help in acute setting
    
  • May help determine chronicity of exposure in select populations
    

• Plain abdominal radiographs to look for radiopaque foreign body
  
• Cranial CT/other studies as indicated by patient’s condition
  

• Acute toxicity:
  
  • Acute appendicitis/colitis/gastroenteritis
    
  • Celiac disease
    
  • Cholera
    
  • Distributive shock
    
  • Encephalopathy
    
  • Toxic ingestions
    
    • Amanita
      mushroom poisoning
      
    • Cyclic antidepressants or other seizure-inducing toxins
      
    • Organophosphates
      
• Chronic toxicity:
  
  • Addison disease
    
  • Guillain–Barré syndrome or other neuropathy
    
  • Raynaud phenomenon
    
  • Thromboangiitis obliterans, or other vasculitides
    
  • Vitamin deficiency (B
    ₃
    , B
    ₆
    , or B
    ₁₂
    )
    
  • Wernicke–Korsakoff syndrome