GIM Week 6 Summary

Question 26

What is the definition of delirium?
Delirium is an acute change in cognition characterized by altered attention and awareness, fluctuating confusion/lucidity in a 24hr period, and typically precipitated by an underlying medical cause.

Delirium can also be associated with perceptual disturbances.

How can you manage it?
Management of delirium includes the following:

• Treat the underlying cause (i.e. infection, pain, metabolic derangement)
• Reorientation techniques:
  • Avoid moving the patient to new environments
  • Have familiar family members be with the patient
  • Correct sensory deficits (i.e. glasses, hearing aids if needed)
• Exposure to sunlight to re-establish circadian rhythm
• Neuroleptic medication if severe agitation:
  • Haloperidol
  • Risperidone, olanzapine, quetiapine (use of atypical antipsychotics has been linked to increased mortality)

Resource
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. 5th ed. Washington, DC: American Psychiatric Association; 2013.

Question 27

A 25 year old man presents to emerge with dyspnea and wheezing on exam. He states that last week he developed a “cold.” He has a 10-year history of asthma. Last year he was admitted to hospital three times for asthma exacerbations, with one ICU admission. He has a personal and family history of atopy.

1. What information in this patient’s history make you concerned for a severe asthma exacerbation?
   The following information on history are red flags for a severe asthma exacerbation:
   • Several admissions to hospital for asthma exacerbation within the last year
   • Prior ICU admission for asthma exacerbation
2. What physical exam signs would you look for to determine the severity of his asthma exacerbation?
   The following physical sings indicate a severe asthma exacerbation:
   • Unable to speak in full sentences
   • Respiratory distress
   • Pulsus paradoxus
   • “silent chest”
   • Hypoxia
   • Peak flow <150L/min is very worrisome
3. What is your acute management of this patient?
   Acute management of an asthma exacerbation includes the following:
   • Stabilize ABCs
   • Short acting beta agonist: Ventolin 4-8 puffs q10min x3
   • Short acting anticholinergic: Atrovent 4-8 puffs q10min x3
   • Steroids: Prednisone 40-80mg PO OD x7-10d
   • O₂ supplementation to keep O₂ sat > 90%

Resource
Lazarus SC. Clinical practice. Emergency treatment of asthma. N Engl J Med. 2010, 363:755-764.

Question 28

You are called to assess a patient on your ward who is complaining of an itchy rash (that appears urticarial), facial flushing and diarrhea shortly after taking penicillin.

1. What reaction is this?
   This is an example of anaphylaxis.
   Anaphylaxis is an IgE-mediated type 1 hypersensitivity reaction. Symptoms are caused by the release of histamine and other inflammatory mediators from mast cells and basophils in response to a specific allergen. This is a medical emergency, as upper airway problems and shock can develop rapidly.
2. What are the possible symptoms of this particular reaction?
   Symptoms of anaphylaxis can include:
   • Urticaria
   • Angioedema
   • Dyspnea, wheezing
   • Upper airway edema
   • Dizziness, syncope, hypotension
   • Nausea, vomiting, abdominal pain, diarrhea
   • Flush
   • Headache
   • Rhinitis
   • Substernal pain
   • Pruritus without rash
   • Seizure
3. How would you manage this?
   The mainstay of treatment is ensuring the patient is stable and has a patent airway, and treating shock:
   • Call for help: get someone with advanced airway skills in the event of rapid upper airway problems
   • Stabilize ABCs
     • If difficulty breathing develops use orotracheal tube or nasotracheal tube (consider intubation in severe cases)
     • Ensure O₂ supplementation – 100% O₂ via non-rebreather face mask
     • Obtain IV access
     • Monitor vitals
   • Epinephrine 0.3-0.5mg IM of 1:1000
   • Ventolin (if wheezing occurs)
   • Antihistamines (give both)
     • Diphenhydramine 50mg IV (H1 receptor blocker, aka Benadryl)
     • Ranitidine 50mg IV (H2 receptor blocker)
   • Methylprednisone 1mg/kg IV can be given after stabilization – some evidence that this helps in preventing a second phase reaction
   • Monitor patient for the next 24 hours for a second phase reaction

Resource
Ellis AK and Day JH. Diagnosis and management of anaphylaxis. CMAJ. 2003, 169:307-311.

Question 29

A 32 year old man is admitted to hospital with a decreased level of consciousness, fever and neck stiffness.

1. What diagnosis are you most worried about?
   This patient’s clinical picture suggests acute bacterial meningitis, which needs to be managed promptly.
2. What diagnostic tests can you do to confirm your diagnosis?
   The time to treatment should be as short as possible, and should be administered prior to investigations if highly suspicious for meningitis.
   Diagnostic tests include:
   • Lumbar puncture to analyze CSF and CSF culture and sensitivity.
     The following findings support the diagnosis of bacterial meningitis (in up to 10% of patients these findings can be normal):
     • Leukocyte count ≥ 2000 x 10⁶/L
     • CSF glucose level <1.9 mmol/L
     • CSF:blood glucose ratio <0.23
     • Positive gram stain in the CSF
   • CT head: evidence suggests that CT head should only be done if the patient presents with coma, papilledema and/or focal neurological deficits. In such a case, antibiotic therapy should be instituted before a CT head is done, and lumbar puncture should immediately follow the CT head
3. What empiric therapy would you start this patient on?
   Empiric antibiotics should be aimed at treating the most common pathogens of bacterial meningitis: Streptococcus pneumoniae, Hemophilus influenza, Neissiria meningitides, and Listeria monocytogenes (more common in elderly, immunocompromised or pregnant patients).
   Therapy should include ceftriaxone (ceftazidime if suspect Pseudomonas infection), vancomycin (for possible resistant Streptococcus pneumonia), and ampicillin (if considering Listeria).
   The patient in this case should receive:
   • Ceftriaxone 2g IV q12h + vancomycin 1g IV q8h

   Dexamethasone can be administered at or prior to the first dose of antibiotic (evidence suggests this reduces morbidity and mortality):

   • Dexamethasone 10mg IV q6h x4d

   Acyclovir can be added as empiric therapy in case of viral meningitis (patients with viral meningitis typically do not appear as sick, yet present with higher fevers).
   Infection prevention and control and infectious diseases should be contacted early on in the management of a patient with meningitis.

Resources
Moayedi Y and Gold WL. Acute bacterial meningitis in adults. CMAJ. 2012, 184:1060. Doi: 10.1503/cmaj.111304.
Quagliarello VJ and Scheld WM. Treatment of bacterial meningitis. N Engl J Med. 1997, 336:708-716.

Question 30

A patient on your ward develops a red, hot, painful, well-defined rash on his right lower leg. You notice he has a temperature of 39⁰C.

1. What is your differential diagnosis?
   The differential diagnosis for this patient includes:
   • Cellulitis (most likely)
   • Erysipelas
   • Venous stasis dermatitis (bilateral, progressive, history of venous stasis dermatitis)
   • Deep vein thrombosis (recent immobilization, orthopaedic surgery, malignancy, history of DVT)
   • Necrotizing fasciitis (crepitus +/- pain out of proportion)
   • Gout, septic arthritis (focused on a joint)
   • Adverse drug reaction (known drug allergy, diffuse rash, onset after drug administration)
   • Malignancy (weight loss, progressive)
2. You suspect he has cellulitis. What are the common pathogens underlying this condition?
   Common pathogens for cellulitis involve gram positive organisms typically found on the skin: Group A Streptococcus, Staphylococcus aureus (especially if purulent lesion).
3. What is your initial treatment?
   Empiric antibiotics typically involve cephalexin/cefazolin for the common pathogens:
   • Cephalexin 500mg PO qid for 5-7days
   • Cefazolin 1-2g IV q8h for 5-7days (if unable to tolerate PO)

   If penicillin allergic:

   • Clindamycin 450mg PO qid (or 600mg IV TID)
   • Moxifloxacin 400mg PO daily or levofloxacin 500mg PO daily
   • Linezolid 600mg PO BID (usually needs infectious disease approval)
   • Vancomycin 1g IV q12h

   In diabetic patients there is a concern for polymicrobial infections, and therefore consideration should be given for starting ciprofloxacin and clindamycin.

Resource
Swartz MN. Clinical practice. Cellulitis. N Engl J Med. 2004, 350:904-912.