Archive | February, 2017

Peds “step by step”(for FWS)

27 Feb

submitted by Amit Kumar, M.D.

 

“Step by Step”

-Algorithm to identify pediatric patients (<90 days) with fever without a source (38°C, in patients with a normal PE and no respiratory symptoms or a diarrheal process) as low risk for invasive bacterial infection

-Developed by European group of EPs, validated

-Identifies “low risk” group not requiring LP and empiric antibiotics, and fit to be managed outpatient

-Found to be more sensitive than Rochester Criteria and Lab-score

step-by-step-algorithm

(Pediatric Assessment Triangle = appearance, work of breathing, circulation)

(PCT = procalcitonin)

-There, add it to your toolbox!

References:
Gomez, B., Mintegi, S., Bressan, S., Dalt, L. D., Gervaix, A., & Lacroix, L. (2016). Validation of the “Step-by-Step” Approach in the Management of Young Febrile Infants. Pediatrics, 138(2). doi:10.1542/peds.2015-4381

Pediatric assessment triangle article

NEPHROLITHIASIS (quick review)

10 Feb

submitted by Christina Brown, M.D. 

Kidney stones:anatomy_kidneystones

  • Most common cause of renal colic
  • Stone composition:
    • 80%: Calcium stones (calcium oxalate > calcium phosphate)
    • 5% uric acid
    • Others: Magnesium ammonium phosphate (struvite), cystine
  • Associated with infections caused by urea-splitting organisms (eg, Pseudomonas, Proteus, Klebsiella) along with an alkalotic urine
  • 90% of urinary calculi are radiopaque.

 

Epidemiology and Etiology

  • 1% of the population
  • Twice as common in men as women
  • Theories on stone formation:
    • Urinary supersaturation of solute followed by crystal precipitation
    • Decrease in the normal urinary proteins inhibiting crystal growth
    • Urinary stasis from a physical anomaly, catheter placement, neurogenic bladder, or the presence of a foreign body

 

Pediatric Considerations

  • Rare in children
  • When present, indication of an overt metabolic or genetic disorder
  • Painless hematuria common presentation (up to 30%)

 

Causes of stone formation:

  • Metabolic abnormalities (50%)
  • Urologic abnormalities (20%)
  • Infection (15%)

 

History

  • Sudden onset of severe pain in the costovertebral angle, flank, and/or lateral abdomen
  • Colicky or constant pain: Patient cannot find a comfortable position
  • Hematuria: Gross hematuria in 1/3 of patients
  • Nausea/vomiting

 

ESSENTIAL WORKUP

  • Urinalysis
  • Microscopic hematuria present in >80%
  • Gross hematuria
  • Absent urinary blood in 10–30%
  • No correlation between the amount of hematuria and the degree of urinary obstruction
  • WBC/bacteria suggests infection

 

Imaging – CT:

  • Helical CT has replaced IV pyelogram (IVP) as test of choice.
  • Detects calculi as small as 1 mm in diameter
  • Advantages over IVP:
    • Performed rapidly
    • Does not require IV contrast media
    • Detects other non-urologic causes of symptoms, such as abdominal aortic aneurysms (AAAs)
  • Indications:
    • 1st-time diagnosis
    • Persistent pain
    • Clinical confusion with pyelonephritis

 

Renal Ultrasound:

  • unilateral hydronephrosis suggests possible obstructive stone
  • no radiation involved, but does not eval for non-urologic causes of symptoms

 

ED TREATMENT/PROCEDURES

  • Hydration:
    • Initiate IV crystalloid infusion with 1 L of normal saline infused over 30–60 min followed by 200–500 mL/hr.
    • Bolus volume compromised patients with 500-mL increments until urine output adequate
  • Analgesics (morphine, ketorolac):
    • Combination of IV NSAIDS and opioids decrease ED stay.
  • Antiemetics (prochlorperazine, ondansetron, droperidol, hydroxyzine)
  • α-Blockers (tamsulosin) or calcium-channel blockers (nifedipine) have been shown to decrease time to spontaneous stone passage:
    • Most efficacious for stones <5 mm in diameter
    • Tamsulosin and nifedipine equally effective
    • prescribe on discharge.

 

DISPOSITION

Admission Criteria

  • Obstruction in the presence of infection mandates immediate urologic intervention.
  • Intractable pain with refractory nausea and vomiting
  • Severe volume depletion
  • Urinary extravasation
  • Hypercalcemic crisis
  • Solitary kidney and complete obstruction
  • Relative admission indications (discuss with urologist):
    • High-grade obstruction
    • Renal insufficiency
    • Intrinsic renal disease
    • Stones of size <5 mm usually pass spontaneously; those >8 mm rarely do.

Discharge Criteria

  • Normal vital signs
  • No evidence of concomitant urinary tract infection
  • Adequate analgesia
  • Able to tolerate PO fluids to maintain hydration status

 

PEARLS AND PITFALLS

  • Do not miss a vascular catastrophe mimicking as renal colic.
  • Aggressive pain management and hydration promote passage of stones
  • The absence of hematuria does not exclude the diagnosis of acute renal colic.

 

References:
1. Bartosh S M.: Medical management of pediatric stone disease. Urol Clin North Am. 2004; 31:575–587. [PMID: 15313066]
2. Hollingsworth J M, Rogers M A, and Kaufman S R et al.: Medical therapy to facilitate stone passage: A meta-analysis. Lancet. 2006; 368:1171–1179.
3. Marx J A, Hockberger R S, and Walls R M: eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 7th ed.St. Louis, MO:Mosby;2009.

4. picture

VASOPRESSORS & INOTROPES (PEARLS)

2 Feb

Submitted by Amit Kumar, M.D.

RECEPTOR PHYSIOLOGY:

Alpha 1: In vascular walls; causes: vasoconstriction

Beta 1: In heart; causes: increased inotropy & chronotropy

Dopamine: In renal, splanchnic, cerebral, coronary vascular beds; causes: vasodilation

Vasopressin: V1 receptors in vessels; causes: vasoconstriction, V2 receptors in kidney; maintains osmolality via ADH

pressors_tintinallis

AGENTS:

VASOPRESSORS (A-1 adrenergic):

Norepinephrine (Levophed):

  • Works on A1 and B1 receptors
  • Causes: Potent vasoconstriction (+reflex bradycardia) and modest increase in CO; latter negated by reflex tachycardia
  • 1st line treatment for septic shock
  • 0.5-10mcg/min, titrate up

Phenylephrine (Neo-Synephrine):

  • Works on A1
  • Causes: Potent vasoconstriction
  • 100-180mcg/min. Once BP stable, titrate down to 40-60mcg/min

Epinephrine (Adrenalin)

  • Works primarily on B1, some on A1 and B2. Increase A1 activity in higher doses
  • Causes: Increased CO. At higher doses causes vasoconstriction as well.
  • 1st line for anaphylactic shock, 2nd line for septic shock
  • 0.1-4mcg/kg/min

Dopamine (Intropin)

  • Doses 2-5mcg/kg/min: dopaminergic (vasodilation);
  • 5-10mcg/kg/min: B1 (increased CO);
  • >10mcg/kg/min: A1 (increased vasoconstriction)

INOTROPE (B-1 adrenergic):

Dobutamine (Dobutrex)

  • Works on B1
  • Causes: Increased CO (+ reflex vasodilation)
  • 2.5-20mcg/kg/min

INOTROPE (PDE-inhibitor):

Milrinone (Primacor)

  • Optional loading dose: 50mcg/kg over 10 mins, followed by 0.125-0.75mcg/kg/min

ADH:

Vasopressin (Pitressin)

  • 0.03-0.04U/min
  • Causes: vasoconstriction

GENERAL CONCEPTS:

-Avoid reflex hypotension by titrating pressors down

-Gold standard: use central lines. For extravasation, use phentolamine 5-10mg SC including through the infiltrated line.

-Hypovolemia should be corrected first to achieve maximal vasopressor efficacy

-Do not use low-dose dopamine solely for “renal protection”/to increase UOP

REFERENCES:

-Dellinger RP, Levy MM, Rhodes A, et al. Surviving sepsis campaign: international guidelines for management of severe sepsis and septic shock: 2012. Crit Care Med 2013; 41:580.?

-Hollenberg SM. Vasoactive drugs in circulatory shock. Am J Respir Crit Care Med 2011; 183:847.?

-Picture: Tintinalli’s