Podcast #322: Methemoglobinemia

Author: Nick Hatch, M.D.

Educational Pearls:

  • Methemoglobinemia is when the iron in hemoglobin is in the Fe3+ (ferric) state rather than the normal Fe2+  (ferrous) state. Methemoglobin cannot release oxygen at the tissues.
  • Symptoms include cyanosis, headache, tachycardia, dyspnea, and lethargy.
  • Suspect in setting of hypoxia that does not improve with oxygenation, and clinical cyanosis with a normal PaO2 on ABG.
  • Treatment is methylene blue which reduces the iron back to the ferrous state.
  • Causes can be Dapsone, Lidocaine, Benzocaine.

 

References:

Agarwal N, Nagel RL, Prchal JT. Dyshemoglobinemias. In: Disorders of Hemoglobin: Genetics, Pathophysiology, and Clinical Management, 2nd ed, Steinberg M (Ed), 2009. P.607

Cortazzo JA, Lichtman AD. (2014). Methemoglobinemia: a review and recommendations for management. Journal of Cardiothoracic and Vascular Anesthesia. 28:1043.

Darling R, Roughton F. (1942). The effect of methemoglobin on the equilibrium between oxygen and hemoglobin. American Journal of Physiology. 137:56.

Podcast #321: Migraine Treatment in ED

Author: Jared Scott, M.D.

Educational Pearls:

  • Recent study compared Compazine with Benadryl vs. Dilaudid for acute migraine management in the ED.
  • Compazine + Benadryl demonstrated migraine relief in 60% of patients compared to the 31% of patients who were relieved with Dilaudid.
  • Compazine + Benadryl is a superior migraine treatment than Dilaudid.

References:

Friedman BW, et. al. (2017). Randomized study of IV prochlorperazine plus diphenhydramine vs IV hydromorphone for migraine. Neurology. 89(20):2075-2082

Podcast #320: PE in Pregnancy

Author: Don Stader, M.D.

Educational Pearls:

  • Pulmonary embolism is one of the leading causes of maternal mortality.
  • There is disagreement among different medical societies about the value of D-dimer as a screening modality. If you use it, consider the rational D-dimer approach whereby you add 250 to your cut-off for every trimester.
  • A useful screening modality is an ultrasound of bilateral lower extremities looking for DVT.
  • Keep in mind, both a V/Q scan and CT scan have a significant amount of radiation. CTA is probably the right diagnostic test (less radiation than CT w&w/o).
  • Always use the shared decision-making model and clinical acumen to choose your tests.

References:

Leung AN, et. al. (2011). An official American Thoracic Society/Society of Thoracic Radiology clinical practice guideline: evaluation of suspected pulmonary embolism in pregnancy. American Journal of Respiratory and Critical Care Medicine. 184(10):1200-8

 

Polak JF, Wilkinson DL. (1991). Ultrasonographic diagnosis of symptomatic deep venous thrombosis in pregnancy. American Journal of Obstetrics and Gynecology. 165(3):625-9.

Sachs BP, et. al. (1987). Maternal mortality in Massachusetts. Trends and prevention. New England Journal of Medicine. 316(11):667-72.

Check out this episode!

Podcast #319: Cardiac Arrest Survival Factors

Author: Aaron Lessen, MD

Educational Pearls:

  • Shockable rhythms like V-fib or V-tach have a better prognosis than patients with PEA or asystole.
  • Recent study has shown an initial electrical frequency in PEA between 10-24/min had worse outcomes than PEA with initial rhythm over 60/min.
  • Patients with an initial electrical frequency in PEA over 60/min did just as well as patients with shockable rhythms. Of them, there was a 22% survival rate with 15% having a good neurologic outcome.

References:

Weiser, C., et al. (2018). Initial electrical frequency predicts survival and neurological outcome in out of hospital cardiac arrest patients with pulseless electrical activity. Resuscitation. 125:34-38

Podcast #318: Nystagmus

Author: Erik Verzemnieks, M.D. 

Educational Pearls:

-Common causes of nystagmus: Congenital disorders, CNS diseases (MS, CVA), Intoxication

-Drugs associated (ETOH, Ketamine, PCP, SSRI, MDMA, Lithium, Phenytoin, Barbiturates)

-If a patient has nystagmus and is intoxicated, consider other drugs and etiologies as potential sources

References:
Alpert JN. (1978). Downbeat nystagmus due to anticonvulsant toxicity. ?Annals of

Neurology.? 4(5):471-3.
Rosenberg, ML. (1987) Reversible downbeat nystagmus secondary to excessive

alcohol intake. ?Journal of Clinical Neuroophthalmology?. 7(1):23-5.

Weiner AL, Vieira L, McKay CA, Bayer MJ. (2000). Ketamine abusers presenting to the emergency department: a case series. ?Journal of Emergency Medicine.? 18(4):447-51.

Podcast #317: Elbow Dislocation

Author: John Winkler, M.D.

Educational Pearls:

-Lower mechanisms of injury have a lower chance of an associated fracture or major ligament injury.

-One major concern is having a fracture fragment in the joint (can lead to chronic arthritic pain).

 -Evaluation should involve checking the neurovascular status of the arm and reduce the fracture as soon as possible. Immobilize arm in a sling and consult orthopedics if there is intra-articular involvement.

References:

https://orthoinfo.aaos.org/en/diseases–conditions/elbow-dislocation/

Mehta, JA; Bain, GI. (2004). Elbow dislocations in adults and children. ?Clinics in Sports Medicine.? 23(4):609-27.

Podcast #316: Abnormalities in Alcohol Intoxication

Author: Michael Hunt, M.D.

Educational Pearls:

  • 1% of patients presenting to ED with alcohol intoxication end up going to the ICU.
  • Most common critical illnesses were acute hypoxic respiratory failure, sepsis, and intracranial hemorrhage.
  • Predictive markers: Vital abnormalities (hypoxia, tachycardic, tachypneic, hypothermic, hyperthermia, hypoglycemia) and patients receiving parenteral sedatives had higher incidence of ICU admission.

References:

Klein, LR; et al. (2018). Unsuspected Critical Illness Among Emergency Department Patients Presenting for Acute Alcohol Intoxication. Annals of Emergency Medicine. 71(3):279-288

Podcast #315: Retropharyngeal Infections in Pediatrics

Author: Dr. Karen Woolf, MD

Educational Pearls:

  • Anatomy : base of skull to posterior mediastinum, anteriorly bounded by middle layer of deep cervical fascia and posteriorly by the deep layer, communicates to lateral pharyngeal space bounded by carotid sheath. Lymph node chains draining nasopharynx, sinuses, middle ear, etc. run through it.
  • Epidemiology & Microbiology: most common kids 2-4, (neonates too). Polymicrobial (GAS, MSSA, MRSA, respiratory anaerobes).
  • Signs and symptoms can include pharyngitis, dysphagia, odynophagia, drooling, torticollis, muffled voice, respiratory distress, stridor, neck swelling, and trismus.
  • Exam may show drooling, posterior pharyngeal swelling, anterior cervical LAD, or a neck mass.
  • Imaging: Get CT neck w/IV contrast!
  • DDx: epiglottis, croup, bacterial tracheitis, peritonsillar abscess, trauma, foreign body, angioedema, cystic hygroma, meningitis, osteomyelitis, tetanus toxin.
  • Tx: Unasyn, if not responding add Vancomycin or Linezolid; surgical drainage if airway is compromised.
  • Complications: airway obstruction, sepsis, aspiration pneumonia, IJ thrombosis, carotid artery rupture, mediastinitis.

References:

Craig FW, Schunk JE. Retropharyngeal abscess in children: clinical presentation, utility of imaging, and current management. Pediatrics 2003; 111:1394.

Fleisher GR. Infectious disease emergencies. In: Textbook of Pediatric Emergency Medicine, 5th ed, Fleisher GR, Ludwig S, Henretig FM (Eds), Lippincott Williams & Wilkins, Philadelphia 2006. p.783.

Goldstein NA, Hammersclag MR. Peritonsillar, retropharyngeal, and parapharyngeal abscesses. In: Textbook of Pediatric Infectious Diseases, 6th ed, Feigin RD, Cherry JD, Demmler-Harrison GJ, Kaplan SL (Eds), Saunders, Philadelphia 2009. P.177

Podcast #314: Psychogenic nonepileptic seizures (PNES)

Author: Gretchen Hinson, M.D.

Educational Pearls:

  • PNES vs. epilepsy: postictal state is diagnostic of an epileptic seizure (sonorous respirations and/or confusion, lasting typically 20-30 minutes); Epileptiform seizures show decrease in convulsion frequency, but increase in convulsion amplitude while PNES convulsions demonstrate episodic convulsion amplitudes; and epileptiform seizures usually do not pause.
  • PNES is a form of conversion disorder and can be associated with underlying personality disorder; however there are patients with epilepsy that also can have PNES which complicates the diagnosis and treatment.
  • Patients that are malingering may have flailing movements and might talk during the episodes – both not typical of epileptic seizures or PNES.
  • Treatment for PNES is with psychotropic medications and psychotherapy as opposed to antiepileptic medications

 

References:

Avbersek, A; Sisodiya, S. (2010). Does the primary literature provide support for clinical signs used to distinguish psychogenic nonepileptic seizures from epileptic seizures?.  Journal of neurology, neurosurgery, and psychiatry. 81(7):719-25.

Devinsky, O; Gazzola, D; LaFrance, W. Curt (2011). Differentiating between nonepileptic and epileptic seizures. Nature Reviews. Neurology. 7 (4): 210?220.

Lesser, RP. (2003). Treatment and Outcome of Psychogenic Nonepileptic Seizures. Epilepsy Currents. 3(6):198-200. doi:10.1046/j.1535-7597.2003.03601.x.

Pillaia, JA; Hautab SR. (2012). Patients with epilepsy and psychogenic non-epileptic seizures: An inpatient video-EEG monitoring study. Seizure. 21(1): 24-27.

Podcast #313: Flu Screening

Author: Peter Bakes, M.D.

Educational Pearls:

  • High risk patients: underlying lung disease, immunocompromised, extremes of age (<2 or >65), underlying cardiac/renal/neurologic disease, and pregnant women.
  • Testing: RT-PCR (RNA based test that is both sensitive and specific)
  • Workup: comorbidities dictate whether or not they are screened; CXR indicated in high risk patients with respiratory symptoms.
  • Morbidity from flu comes from secondary pneumonia, sepsis, and septic shock.
  • Treatment options are Tamiflu and Relenza (Relenza is contraindicated in patients with lung disease).
  • High risk patients see average of 2.5 days shortening of illness and a decrease in illness severity. Low risk patients see average of 1.5 days shortening of illness.

References:

https://www.cdc.gov/flu/about/disease/high_risk.htm

Binnicker MJ, Espy MJ, Irish CL, Vetter EA. Direct Detection of Influenza A and B Viruses in Less Than 20 Minutes Using a Commercially Available Rapid PCR Assay. J Clin Microbiol. 2015 Jul; 53(7): 2353-4.

Longo, Dan L. (2012). “187: Influenza”. Harrison’s principles of internal medicine (18th ed.). New York: McGraw-Hill. ISBN 9780071748896.