This week we talked about the management of anaphylaxis and a rare case of systemic mastocytosis. See our previous blog posts on anaphylaxis. Life saving key points:
- ABCs! Consider intubation early if there is stridor or airway edema
- 35% of intravascular volume can go extravascular in <10 minutes because of inappropriate vasodilation. IV fluids!
- The dose of epinephrine is 0.5 mg. Depending on the vial concentration, this is either 0.5mL of 1:1000 (1mg/ml) IM injection, or 5mL of 1:10 000 (0.1mg/mL) of a slow IV push
Mastocytosis is a disorder of excessive mast cell accumulation, arising from genetic mutations in the bone marrow. The clinical presentation may vary:
- Cutaneous: A variety of skin manifestations including nodules or a maculopapular rash. Darier's sign is urticaria and redness when the skin lesions are rubbed or scratched
- Systemic: Infiltration of mast cells into different organs can lead to end-organ effects, such as cytopenias
- Work-up for mastocytosis includes a serum tryptase level, bone marrow biopsy and skin biopsy if lesions are present
- Symptoms of mast cell degranulation, including recurrent anaphylaxis, can occur with both cutaneous and systemic forms. Identifying common triggers can help manage this condition, in addition to medications like H1/H2 blockers and anti-leukotrienes
- Flash pulmonary edema occurs when there is an acute increase in end diastolic pressure, creating rapid accumulation of fluid in the lung interstitium and alveoli
DDx:
Acute valve rupture or regurgitation
Diastolic dysfunction + stress like HTN or afib
Myocardial injury - ischemia, infarction etc
Hypertensive emergency
"Pickering syndrome" of bilateral renal artery stenosis - an indication for renal artery revascularization
- Adrenal insufficiency should be on the differential if a patient has nonspecific symptoms, such as weakness, fatigue, nausea/vomiting, abdominal pain, confusion or presyncope
- Primary versus secondary? Primary adrenal insufficiency can have hyperkalemia, hyperpigmentation and more severe hypotension compared to a pituitary cause. Hyponatremia can actually be found in both - either from lack of mineralocorticoids (primary) or from SIADH (secondary)
- Treatment of an adrenal crisis is IV fluids and hydrocortisone 100 mg IV Q8H. If this is a new diagnosis then all labs should be drawn before steroids are given. If the patient is not acutely ill, a morning cortisol level and ACTH stim test are used to confirm the diagnosis
- Here is a review on adrenal insufficiency
- Cauda equina or spinal cord compression is a medical emergency that requires immediate attention. Severe back pain, saddle paresthesia, weakness, bladder retention or bowel incontinence are all symptoms of compression
- On exam, there may be signs of upper or lower motor neuron weakness depending on where the compression is (spinal cord vs the cauda equina nerve roots)
- Dexamethasone can decrease spinal cord edema if compression is confirmed. An urgent surgery consult for possible decompression is needed. There is also a role for radiation depending on the cause of compression, for example in metastatic bone disease
- Based on the American College of Radiology guidelines, other 'red flags' of back pain that require imaging include age > 70 (or > 50 with osteoporotic risk factors), history of cancer or surgery, unexplained fever or weight loss, immunocompromised state, IV drug use, trauma, or if the back pain persists for greater than 6 weeks
- Delirium tremens can occur 48-96 hours after withdrawal of alcohol and is associated with increased mortality. The clinical triad includes delirium, tremors and autonomic instability. DTs are treated with benzodiazepines - neuroleptics should be avoided because they can lower the seizure threshold and precipitate arrhythmias (long QT)
- Hallucinations that occur within 12-24 hours (with normal vitals) are from alcoholic hallucinosis. They should resolve by 48 hours and are treated conservatively
- Giving lorazepam 2 mg IV after an alcohol withdrawal seizure has been shown to decrease recurrent seizures in this RCT
- Patients suspected of having meningitis require an LP and early antibiotic therapy. No single item on history or physical exam is accurate enough to rule in or out meningitis:
- Signs of meningeal irritation such as Brudzinski or Kernig's are rarely seen in patients with meningitis (low sensitivity). Nuchal rigidity is commonly seen in elderly patients without meningitis (low specificity)
- Although there is limited data, the jolt accentuation maneuver may be the most helpful sign in meningitis
- Four days of dexamethasone started before or with the first dose of antibiotics has been shown to decrease mortality. The subgroups that benefited most in this RCT were patients with strep pneumonaie meningitis or severe disease (GCS < 11)
- Check out the official IDSA guidelines to review the complete management of meningitis
Check out our previous blog posts on ascites and SBP
Here is a helpful flowchart that reviews the pathophysiology of ascites in cirrhosis - thanks Calgary med students!
- In a patient with diabetes, hypoglycemia is defined as bs < 4
- In a patient without diabetes, the diagnosis should be based on Whipple's triad:
1) Symptoms consistent with hypoglycemia
2) A low plasma glucose when symptoms are present (often bs < 2.5 used)
3) Improvement of symptoms when glucose normalizes
- Does the patient look sick? Secondary causes of hypoglycemia include sepsis, adrenal insufficiency, liver or kidney failure
- No obvious cause? Specialized investigations to determine exogenous versus endogenous insulin production should only be tested when hypoglycemia is present
- C-peptide is a byproduct created when insulin is made in the body, so levels will only be elevated with endogenous insulin production. Don't forget that medications like sulfonylureas will cause an elevated C-peptide because they stimulate endogenous insulin production
