Grand Rounds Recap 10.12.2016

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Coagulation Studies with Dr. Murphy-Crews

Read the background and introductory post here first

How do we measure these pathways?

  • aPTT measures the intrinsic pathway
  • PT/INR measures extrinsic which includes Factor VII

Case #1: MCA stroke in a patient who is on “medicines for her atrial fib” and has an INR of 1.4. Can you assume she is just therapeutically anti-coagulated?

  • No. NOACs can elevate your INR
  • How do we screen for NOACs?
    • Bottom Line
      • No consistent marker across NOACs
      • Thrombin Time (TT) may be sensitive for dabigatran
      • Anti-Xa may be sensitive for Xa inhibitors
    • Dabigatran
      • A normal TT essentially excludes clinically significant dabigatran levels
      • PT/aPTT are less sensitive and may be normal despite clinically active drug levels (1/5 people with dabigatran have normal PTT)
      • Dilute TT and Ecarin clotting time may provide more linear relationship but are not widely available or rapid
    • Rivaroxaban
      • Increases the PTT but sensitivity is varies
      • A normal PT cannot exclude
      • aPTT has very poor correlation
      • anti-Xa sensitive by not timely enough
    • Apixaban
      • PT/aPTT may prolong but not consistently

Case #2: Enoxaparin and warfarin with a subdural hematoma 

  • Enoxaparin: protamine
  • Warfarin: FFP v PCCs
  • Activated charcoal for any NOAC ingestion<2h 
  • Dabigatran- hemodialysis
  • Xa inhibitors- PCCs?

What about an asymptomatic INR?

Case #3: Elevated INR and Cirrhosis

  • What does an elevated INR mean in cirrhosis
    • due to synthetic dysfunction in the liver
  • Synthetic dysfunction tends to decrease both pro coagulants and anticogulant factors
  • Most sources recommend INR <2, Plt >20K to do a large volume paracentesis, although TEG better marker of functional anticoagulation if true coagulation status needed

Case #4: DIC

  • Labs: low platelets, normal or increase INR, aPTT normal or increased, Fibrinogen low, D-Dimer normal or increased, peripheral smear with helmet cells
  • Treatment: treat underlying causes
    • Temporize with transfusions only as needed

Case Follow-up with Dr. Winders

Middle aged female with COPD, Chiari malformation s/p surgery, hyperthyroidism, heroin abuse, depression presenting with concerns for seizure. 2 episodes of shaking in her sleep with bowel and bladder incontinence. Normal neurological exam. TSH elevated. Ventricular bigeminy then found to have runs of wide-complex tachycardia, had 2 episodes of torsades with ROSC and found to have prolonged QT secondary to hypokalemia. 

QT Interval

  • Start at earliest Q to end of T
    • II, V5
  • Bazett’s Formula= QT/sqroot(RR)
    • Overestimates in tachycardia
  • QTc of 480 has 98% sensitivity for TdP
  • QTC of 500 93% sensitivity but improved specificity for TdP

Drug Induced QT-prolongation

  • Does low-dose droperidol administration increase the Risk of Drug-induced QT prolongation? 3000 with only 3 adverse events

TdP: Risk Factors

  • QT Prolongation —> 4x risk suddent cardiac death with QTc >500
  • Women 
  • Heart disease
  • Polypharm
  • Bradycardia
  • Advanced age
  • HypoK/HypoMg

TdP: Treatment

  • Electrolytes
  • Remove offending pharmacology
  • Overdrive pacing
  • Class IB anti-arrhythmic 
  • Goal of HR >90

R1 Diagnostics Lecture: Synovial Fluid Analysis with Dr. Harty

See his introductory post here for some background first

Case #1: Young male patient with STI exposure with acute R knee pain and swelling

  • WBC 60,000; clear gram stain; culture pending
  • WBC count and diff in septic arthritis
    • Sensitivity of 50,000: 56%
  • Gram stain
    • Positive in 71% gram +
    • Positive in ~40-50% gram - 
    • Positive in <25% gonococcal causes

Case #2: 40yo with alcoholism with knee pain

  • WBC 90,000: clear gram stain, culture pending; needle shaped crystals with neg birefringence
  • Septic arthritis can happen concurrent with crystal disease

Discharge, Treat, or Transfer: Management of Facial Trauma in a Community ED

Facial Fractures:

  • Diagnosis: L tripod fracture, orbital floor fracture
  • Treatment: Who gets fixed?
    • Those who are entrapped need to be fixed in 24h
    • Forced ductions 
  • Follow-up: Who gets followed-up?
    • Cosmesis 
  • Complications: Facial deformity
    • Diplopia: higher % if not fixed in 2 weeks

Lip lacerations

  • Diagnosis: Facial laceration violating the vermillion border
  • Repair: 
    • Begin with the structures that require alignment (lip, eyebrow)
    • Repair orbicularis oris musculature with Vicryl 
  • Complications
    • Asymmetry if appropriate anatomic structures are not well-aligned

Auricular lacerations

  • Treatment: Repair
    • Typically including cartilage, Vicryl
    • Bolster on both sides 
  • Complications: Deformity from failure of cartilage to approximate or auricular fibrosis from hematoma

Lip Lacerations

  • Treatment:
    • <1cm: no repair
    • complex repair including muscle 
  • Complications
    • deformity

Nasal lacerations in to the ala

  • Diagnosis: Nasal laceration extending into the nasal cavity
  • Treatment: Full thickness repair without tension
  • Complications: deformity, missed lacrimal duct injury

Nasal Fractures

  • Diagnosis: displaced nasal bone fracture
  • Treatment: regional anesthesia vs sedation and reduction
  • Complications: deformity

Mandibular fractures

  • Do not need to transfer
  • DO need to follow-up as they generally get fixed within a week

Summary:

  • Follow-up matters
  • Trust your skills, communicate with your patients

 

EM-Peds Joint Lecture: Asthma & Bronchiolitis

Asthma:

  • Treatments:
    • Albuterol +/- ipratropium
      • MDI vs neb vs continuous
    • Steroids
    • Mg
    • NS bolus

Albuterol MDI & Spacer: same as or better than nebulizers

Dexamethasone vs Prednsione: 

  • No difference in relapse, revise to ED, sx improvement, and admission
  • Benefits: less vomiting, convenience for patients, improved compliance with completion

Early use of steroids: systemic corticosteroids within 1 hour of presentation to the ED, reduces admission

PRAM (Pediatric Respiratory Assessment Measure)

  • 18 months - 7 yo presenting with wheezing
    • PRAM >8 at 90 min predictive admission, don’t use triage PRAM score
      • 50% sensitivity
      • 98% specificity
      • PPV 73%
      • AUC 0.85
  • O2 Saturation
    • >95%  + 0
    • 92-94% + 1
    • <92% + 2
  • Suprasternal Retractions
    • Present +2
  • Scalene Muscle Use
    • Present +2
  • Air Entry
    • Normal + 0
    • Decreased at the base + 1 
    • Decreased at the apex and the base + 2 
    • Minimal or absent + 3
  • Wheezing
    • Absent + 0
    • Expiratory only + 1
    • Inspiratory (+/- expiratory) + 2
    • Audible without stethoscope or silent chest + 3 

Mild PRAM Score 0-3

  • Albuterol MDI & Spacer
  • Dexamethasone 
  • If repeat score is 0-3 after treatment, may go home
  • If repeat score is higher, move algorithms 

Moderate PRAM Score 4-7

  • 3 back-to-back nebulizer albuterol/atrovent
  • Dexamethasone
  • If repeat immediate post treatment PRAM score is
    • 0-7, observe for 60 min then re-score:
      • 0-3 d/c home
      • 4-7 albuterol neb admit on q1h
      • >8 to severe algorithm, impending resp failure to appropriate algorithm
    • >8 go to severe algorithm
    • Impending respiratory failure to appropriate algorithm

Severe PRAM Score 8-12

  • 3 back-to-back nebulizer albuterol/ipratropium
  • Dexamethasone
  • IV placement + NS bolus
  • Mg bolus 
  • MIVF after bolus
  • If repeat PRAM score immediately post treatment
    • 0-7 then attempt to space to q1h albuterol nebs
    • >8 then admit on continuous to PICU or stepdown

Status asthmaticus

  • 3 back-to-back & IV methylprednisone
  • IV Mg or IM Epi
  • IVF Bolus
  • Terbutaline SQ/IV
  • Consider ketamine

Bronchiolitis

Days 3-5: minute-to-minute variability in lower respiratory symptoms

  • sit it out for 10min, they tend to look better after 10min
  • If they do not look better after 20min, come back in because they are probably not having a minute-to-minute variation anymore

Bronchiolitis Guidelines: 1 month to 23 months without underlying disease processes

  • CXR? No
    • Children <2 with wheezing, radiographic pneumonia is associated with 
      • Temp >38
      • O2 Sat <92%
      • 20% of children with both fever and hypoxia had a radiographic pneumonia
      • Anecdotal rules: Diagnosis not classic based on HPI/physical, both fever and sat <92%, or new fever 5-7 days after illness
    • Recommended
      • Superficial suction
      • Oxygen
      • High Flow Oxygen
      • NG or IV fluids
    • Not recommended
      • Albuterol
      • Racemic Epi
      • Steroids
      • HT saline
      • Antibiotics
    • Fever in bronchiolitis
      • 1/3 of patients with bronchiolitis have fever
        • Usually present early in illness
        • Usually <39
    • Older infants with bronchiolitis: does exist between 12-24 months
    • Higher risk kids:
      • Lung disease of prematurity
      • Congenital heart disease
      • Neuromuscular disorders
      • Immunodeficiency
      • Increased risk of apnea
        • <2 months 
        • preterm and <48wks of adjusted age
        • observed apnea at home
    • Discharge Criteria
      • Age <2 months
        • No tachypnea based on age
      • No or only mild retractions
      • Initial O2 sat >94% (probably okay to be discharged if less than 92%)
      • No or 1 albuterol or epic given in first hour
      • Adequate oral intake

Local Anesthetic Systemic Toxicity with Drs. Bernadoni and Liebman

Categories of local anesthetics

Lidocaine_hci.jpg
  •  Esters (cocaine, benzocaine, procaine, tetracaine)

    • metabolized rapidly by plasma cholinesterase

    • lower potential for systemic toxicity for that reason

  •  Amides (lidocaine, bupivicaine, etc)
    • metabolized in liver
    • higher potential for systemic toxicity
    • *names have “i” before suffix “caine”

Methemoglobinemia

  • Oxidation of iron in hemoglobin from 2+ to 3+
  • Causes left shift of oxygen dissociation curve, concerning for true oxygen carrying capacity in the setting of baseline anemia
  • Generally associated with topical/oropharyngeal benzocaine
  • Usually in context of mucosal defect, enzyme deficiency, or excessive dose (mom keeps slathering oragel on teething child, etc.)
    •  Toxic dose in pediatrics is near 15 mg/kg
  • Particularly concerning with benzocaine spray, can reach toxic dose after only a few sprays in small children
  • At levels of 3-15% in baseline healthy patients, can begin to get low SpO2 saturation, cutaneous discoloration    
  • Treat with methylene blue
    • Treat if levels >25% or if symptomatic

Local Anesthetic Systemic Toxicity (LAST)

  • Symptoms correlate with serum concentration
  • Toxicity also depends on anesthetic given
  • Factors to consider:
    • Dose
    • Rate of administration
    • Site of injection
    • +/- vasoconstrictor
    • Acid-base status of patient serum
    • More acidic blood will have less anesthetic bound to protein
    • Minimum IV toxic dose varies by medication, lidocaine needs near 3x dose to reach toxicity compared to bupivicaine
  • Begins with subjective symptoms (3-6 mcg/ml)
    • Tinnitus, lightheaded, perioral numbness, confusion, lethargy
    • Auditory and visual hallucinations as well
    • Have a high index of suspicion if patients begin to act differently
    • Symptoms usually progress very quickly, within minutes]
    • Can present initially with severe symptoms and cardiovascular collapse, may bypass subjective
  • Mainstay of treatment is intravenous fatty emulsion (IFE) i.e. intralipid
    • Composed of soybean oil and egg yolks (allergies)
    • Three proposed mechanisms of action
      • Lipid sink/sponge theory
        • IFE “soaks up” lipid soluble substances
        • Shunts to non-aqueous areas of body
      • Modulation of intracellular metabolism theory
        • Mass action to overcome alteration of fatty acid metabolism caused by local anesthetic systemic toxicity
      • Activation of ion channels theory

Management of LAST in the ED

  • Surveys conducted in UK ED showed poor results amongst attending physicians and residents regarding specific levels for toxicity or specifics for treatment of LAST
  • Need for increased education in management
  • First for management consider plans for prevention
    • Utilize minimum dose necessary for procedure
    • Consider agent with highest available minimum toxic dose
    • Lidocaine more favorable than bupivicaine in this regard
    • Consider risk factors for LAST
      • Including extremes of age, high and low cardiac output states, and low serum protein states (e.g. cirrhosis), among others
    • Aspirate prior to each injection
    • Ultrasound guidance
      • Shown to result in fewer vascular punctures and lower anesthetic volume required
      • Reduction in LAST by 65%
  • Second: consider monitoring
    • Pulse oximetry
    • HR/BP q 5 minutes
    • 3 lead ECG telemetry
    • Consider end tidal CO2 monitoring based on baseline health/concern for potential phrenic nerve blockade
    • Primary goal is to minimize hypoxia and acidosis (which would worsen/prolong toxicity)
  • Early management of toxicity
    • If early symptoms, 100% O2, intubate as indicated, consider intralipid
    • Seizures
      • Benzodiazepines as mainstay
      • Consider low dose paralytic (minimize acidosis from seizure activity)
      • Lipid therapy
    • Dysrhythmia or cardiac arrest?
      • Lipid therapy
        • Alert ECMO team
      • Begin modified ACLS
        • Epinephrine, give 10-100 mcg titrated to effect/ROSC
        • Amiodarone for persistent ventricular dysrhythmia
        • Avoid vasopressin, CCB, BB, lidocaine
        • Monitor ABG for acidosis and hypoxia
        • Expect prolonged resuscitation
    • Hypotension?
      • Lipid therapy

Lipid therapy: 1.5 ml/kg of lean body mass IV over 1 minute.  Can repeat x1-2.  

  • If improvement is noted, begin 0.25 ml/kg/hr gtt
  • If hypotensive begin 1.5 ml/kg/hr gtt

Other notes:

  • Incidence of delayed LAST >5 minutes appears to be increasing
    • Consider due to ultrasound guidance lowering incidence of accidental IV administration
    • Consider monitoring for 30 minutes after administration