Episode 4 – Transfusions and Ingested Foreign Bodies

Episode 4 – Transfusion Emergencies (iTunes or Listen Here

The Free Open Access Medical Education (FOAM) –from Dr. Ryan Radecki’s erudite blog, Emergency Medicine Literature of Note..

Infections & Transfusions” – a JAMA meta-analysis found that higher hemoglobin targets were associated with an increased incidence of infection with a number needed to harm of 20-38.  The  group with a target level of 7-9 g/dL had an infection rate of 11.8% (95% CI, 7.0%-16.7%)  compared with an infectious complication rate of 16.9% (95% CI, 8.9%-25.4%) in the “liberally” transfused group.

Grilling Injuries on Memorial Day” – Grilling isn’t risk free.  Dr. Radecki reviewed a case series of six individuals who presented in one year to a hospital after ingesting meat cooked on a grill.  Three patients had neck pain with wire grill bristles removed via laryngoscopy and three had abdominal pain necessitating removal – 2 by colonoscopy and 1 with urgent surgery secondary to intestinal perforation.

The Bread and Butter

We summarize some key topics from the following readings,  Tintinalli (7e) Chapters 233; Rosen’s (8e) Chapter 7…but, the point isn’t to just take our word for it.  Go enrich your fundamental understanding yourself!

Transfusion Reactions

Immediate Reactions – great FOAM summary from Life in the Fast Lane: Transfusion Risks, Transfusion Reactions 

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The Ones Our Patients Care About (Infectious – statistics are US based)

  • Bacterial contamination is rare: 1/500,000 – 1/1,000,000
    • Most common pathogen: Yersinia Entercolitica
  • More common in platelets: 1/1000-1/2000 per Rosen, CDC, and the AABB  (Tintinalli cites 1 in 6 million)
  • Most Common virus: Parvovirus B19 (1 in 10,000).  The others are very very rare: HIV and Hepatitis C > 1 in 1 million, Hepatitis B 1 in 100,000-200,000

Ingested Foreign Bodies

  • Beware the button battery. These can cause necrosis within hours in the esophagus and must be removed ASAP.
  • Objects that are irregular, very sharp, or have dimensions greater than 2.5cm in width or 6 cm in length that are still in the stomach or duodenum – call GI to have these removed via endoscopy.

Generously donated Rosh Review questions (scroll for answers)

Question 1 A 55-year-old woman is receiving a blood transfusion due to persistent vaginal bleeding and a hemoglobin of 5 mg/dL. While receiving the transfusion, she develops fever, chills, back pain, pain at the site of transfusion, and tachycardia. [polldaddy poll=8109900]

Question 2 A 28-year-old man presents with a 1-day history of rectal bleeding. In the ED, he is hypotensive, thrombocytopenic, and is found to be passing melena. He receives a transfusion of platelets and packed red blood cells as part of his resuscitation. Twenty minutes after the start of his platelet transfusion, his BP is 90 mm Hg systolic, he becomes dyspneic, and his oxygen saturation drops from 99% on room air to 91% on 2L of oxygen supplementation. On exam, you note rales at the lung apices and that he is using accessory muscles to breathe. His chest radiograph shows diffuse interstitial infiltrates. [polldaddy poll=8109907]

Question 3 [polldaddy poll=8109908]

 

References:

Emery M.  Blood and Blood Products.  Rosen’s Emergency Medicine. 2014: 8th ed. p 75-80.e2

Coil CJ, Santen SA.  Transfusion Therapy  Tintinalli’s Emergency Medicine: A Comprehensive Review. 7th ed.

Hillyer CD, Josephson CD, Blajchman MA, et al. Bacterial contamination of blood components: risks, strategies, and regulation: joint ASH and AABB educational session in transfusion medicine. Hematology Am Soc Hematol Educ Program. 2003:575-89.

1. C – Up to 20% of all transfusions may lead to some type of adverse reaction. Although most of these reactions are minor, some are life-threatening. The patient is having an acute intravascular hemolytic reaction. This occurs when the recipient’s antibodies recognize and induce hemolysis of the donor’s red blood cells and may result in activation of the coagulation system and disseminated intravascular coagulation. This type of reaction typically presents with back pain, pain at the site of transfusion,headache, fever, hypotension, dyspnea, tachycardia, chills, bronchospasm, pulmonary edema, bleeding, and development of renal failure. First, stop the transfusion. Then initiate intravenous hydration to maintain diuresis.

2.D- This patient is most likely suffering from transfusion-related acute lung injury (TRALI), one of the leading causes of transfusion-related mortality. It is most closely associated with platelet and fresh frozen plasma transfusions, though cases have been reported with packed red blood cells since there is some residual plasma in the packed cells. Symptoms begin abruptly during transfusion or within 6 hours and resemble adult respiratory distress syndrome with noncardiogenic pulmonary edema, dyspnea, hypoxemia, and bilateral infiltrates on chest radiograph.

3. A- The patient is experiencing an allergic reaction without serious signs or symptoms. The transfusion does not need to be stopped for such a reaction; an antihistamine will help to relieve symptoms.

Episode 3 – Ear Emergencies

Episode 3 – Ear Emergencies (iTunes

The Free Open Access Medical Education (FOAM) – SMART EM Pseudoaxioms 2 and Literature Update

The podcast reviews:

  • Bullous Myringitis, a painful infection of the tympanic membrane, is typically caused by viruses, strep. pneumoniae and moraxella and, less commonly, mycoplasma.  The boards have caught up with this. Check out this review by Mellick.
  • PHANTOM-S trial: Use of the STEMO (Stroke Emergency Mobile – an ambulance with neurologist and a CT scanner for suspected strokes) reduced mean alarm-to-treatment time by 25 minutes (95% CI, 20-29; P < .001) without an appreciable neurologic benefit for this intensive intervention.
  • An article by Gregg et al in the NEJM discussed incredible improvements in diabetes outcomes as a result of tight glycemic control. Dr. Newman asserts that much of this is secondary to dilution, as the definition of diabetes changed in 1997.  This resulted in more people with less severe disease being diagnosed with diabetes.

The Bread and Butter

We summarize some key topics from the following readings,  Tintinalli (7e) Chapters 237; Rosen’s (8e) Chapter 92.  A good read on common ear emergencies from EBMedicine…but, the point isn’t to just take our word for it.  Go enrich your fundamental understanding yourself!

Bullous Myringitis

This is a painful infection characterized by bullae on the tympanic membrane (TM), which has a richly innervated outer epithelium (hence the severe otalgia). Patients may collect fluid behind their TM or have a concomitant otitis media.

Etiology: viruses, typical otitis media pathogens.  Mycoplasma and chlamydia have been associated with bullous myringitis but the association is unclear and these are not the most common causes.

Treatment: pain control, pain control, pain control.  Antibiotics are optional in most cases. But then again, antibiotics are not necessary in most cases of otitis media.  Both Rosen and Tintinalli are on board with this.

Perforated Tympanic Membrane

Photo:Didier Descouens (Wikimedia Commons)

Etiology: infection, trauma (q-tips, instrumentation), changes in pressure (diving, flying)

Treatment:  Keep the ear canal dry, follow up with ENT.  Most of these patients can go home.  If the injury is in the posteriorsuperior aspect of the TM or secondary to penetrating trauma, they should see ENT within 24 hours because they may have damage to the bones of the middle ear.

Auricular Hematoma

Etiology: Blunt trauma (often associated with boxing, fights, or termed “rugby ear“)

Treatment:  Incision, drainage, and compression dressing/splint.  Photo guide to repair.

Ototoxic Agents (great table in Tintialli 8 e, Ch 237, p1551)

Risk of hearing loss typically increases with exposure to medication (dose and length of use) and issues with clearance such as renal insufficiency may cause medications to hang around longer than anticipated or at higher levels.

Loop Diuretics: furosemide, bumetanide, ethacrynic acid

Salicylates (aspirin and quinine), NSAIDs

Antibiotics that end in -mycin or -micin: aminoglycosides (gentamicin), vancomycin, erythromycin

Chemotherapeutic agents: vincristine, vinblastine, cisplatin, carboplatin

Topical agents: ethanol, polymixin B, neomycin

Sudden Hearing Loss Differential Diagnosis 

Occurs over the span of three days.

Differential Diagnosis categories for any ailment can be remembered by the mnemonic VINDICATE

  • Vascular – sickle cell, polycythemia
  • Infectious/Inflammatory – viruses (zoster oticus or herpes, EBV, CMV, mumps), syphilis, labyrinthitis, temporal arteritis
  • Neoplasms – leukemia, masses,  acoustic neuroma
  • Drugs –  loop diuretics, antibiotics that end in -mycin or -micin (aminoglycosides like gentamicin, vancomycin, erythromycin), salicylates and NSAIDs, chemotherapeutic agents (cisplatin, carboplatin, vinblastine, vincristine, and topical agents (ethanol, polymyxin B, neomycin)
  • Iatrogenic/idiopathic – perforated TM, idiopathic endolymphatic hydrops (Meniere’s disease) – vertigo, hearing loss, tinnitus
  • Autoimmune -granulomatosis with polyangitis (Wegener’s)
  • Trauma – ruptured TM
  • Endocrine – diabetes, high cholesterol

Necrotizing Otitis Externa (Malignant Otitis Externa) – an infection that can turn into osteomyelitis of the skull

Presentation: otalgia, headache, and swelling and tenderness around the ear particularly in the setting of a prolonged course of otitis externa.  Diagnosis often requires CT scan to gauge involvement.

Epidemiology: Diabetics, immunocompromised

Etiology: Pseudomonas (90%)
Treatment:   Pediatrics- imipenem or an aminoglycoside and an antispeudomonal penicillin.  Adults – cephalosporin or quinolone

Dispo: Mild cases with good follow up can get oral quinolones as outpatients. More severe cases – admission, IV antibiotics, and perhaps surgical debridement.

Generously donated Rosh Review questions (scroll for answers)

Question 1.[polldaddy poll=8093105]Screen Shot 2014-06-01 at 9.28.25 PM

Question 2.

A 36-year-old woman presents to the ED complaining of decreased hearing and increased fullness to the right ear. Over the last week, she has used cotton-tipped applicators to attempt to remove cerumen from her right ear. On exam, you notice a cerumen-impacted external canal on the right. You irrigate the right ear with warm saline using an 18-gauge IV catheter and a plastic curette to remove the cerumen. During the procedure, the patient has sudden and complete hearing loss to the right ear. [polldaddy poll=8093098]

 

Question 3. A 16-year-old girl presents complaining of pain behind her left ear. She thought the pain was due to an ear infection and took three of her boyfriend’s leftover antibiotic tablets without seeing her primary care physician. Her ear pain improved for a couple of days, but now she is complaining of fever and discharge from the external auditory canal. Her vitals are T 38.4°C, BP 120/80, HR 108, and RR 18. On physical examination, she has postauricular tenderness, swelling, and erythema. You note purulent otorrhea through a perforated tympanic membrane. [polldaddy poll=8096505]

Answers:

1. D-Bullous myringitis was previously linked to Mycoplasma pneumoniae but it appears, based on middle ear aspirate culture results, that typical acute otitis media pathogens are the true cause. Among these, Streptococcus pneumoniae is most common.
2. C – The patient does not require admission (A) to the hospital. ENT care can be arranged for as an outpatient. Traumatic tympanic membrane perforations do not require otic antibiotics (B) unless the ear was contaminated such as from diving in seawater or the rupture is secondary to infection. The patient should receive more than ac otton ball (D) in her ear. Her management should include analgesia and ENT follow-up because complications of tympanic membrane rupture include facial nerve palsy, vertigo, and hearing loss.

3. C – This patient has necrotizing otitis externa.

References:

Silverberg M, Lucchesi M.  Common Disorders of the External, Middle, and Inner Ear.  Tintinalli’s Emergency Medicine, A Comprehensive Study Guide, ed 7. New York, McGraw-Hill, 2011, (Ch) 237:p 1556-1557.