Cardiac Tamponade

Overview

Pathophysiology

  • Increase in pericardial pressure leads to a decrease in preload
  • As right-sided pressures increase the intraventricular septum moves into the left ventricle decreasing cardiac output

The size of the pericardial effusion is not as important as the rate of fluid accumulation within the pericardium.

Causes

Many potential causes including autoimmune conditions, infection (viral and bacterial), myocarditis, and malignancies.

The two causes to always consider first. Management requires surgical repair.

  • Aortic Dissection
  • Ventricular free wall rupture (examples: post-MI or after pacemaker placement)

Diagnosis

  • Bedside ultrasound is vital in establishing the diagnosis (see video below)
  • IVC with greater 50% collapse is around 97% sensitive for ruling out the diagnosis
  • Pulsus paradoxus, physical exam, and electrical alternans are not reliable in the diagnosis of pericardial tamponade

Management

Definitive Management

  • Definitive management is drainage (see video above)
  • For hemopericardium surgical repair is necessary

Hemodynamic Support 

  • Small fluid bolus staring at 500cc
  • If right ventricular pressures are elevated, then a fluid bolus may decrease cardiac output by causing septal shift into the left ventricle (assess patient’s response to fluid bolus)
  • Norepinephrine for further hemodynamic support
  • Try to avoid dobutamine, epinephrine, and dopamine since they tend to have a greater effect on HR and will decrease diastolic filling time

Emergency Medicine Foam

EM@3AM – Cardiac Tamponade

Approach To Back Pain

 

Red Flags Signs/Symptoms

History Suggestive Diagnosis
New frequent falls, fecal incontinence, urinary urgency, overflow incontinence, bilateral leg symptoms General findings of cord compression/cauda equina
History of weight loss or cancer Epidural tumor/metastasis
Anticoagulation use or recent spinal procedure Epidural hematoma
Fever, immunocompromised, history of IVDU Epidural abscess

Most useful red flags are likely history of cancer, steroid use, abnormal neurologic findings,  difficulty walking, and anticoagulation use.

Patient with no red flags and a normal neurologic examination are at extremely low risk for a serious cause of back pain.

Differential (Serious Causes)

Spinal Pathology

Cancer Related

  • Epidural metastatic disease
  • Intradural metastatic disease
  • Intramedullary tumor

Infectious Related

  • Epidural abscess
  • Vertebral osteomyelitis
  • Infectious discitis

Other

  • Spinal epidural hematoma
  • Central disc herniation with cauda equina

Intrabdominal/Retroperitoneal

  • Aortic dissection
  • AAA
  • Pancreatitis
  • Peptic Ulcer Disease
  • Cholangitis
  • Ureteral colic

Evaluation

Classic presentations are frequently absent making the diagnosis of serious causes of back pain difficult. Many patients with cauda equina syndrome do not have fecal or urinary incontinence or saddle anesthesia on presentation. Only 10% of patients with spinal epidural abscess present with the classic triad of fever, back pain, and neurological deficits. Patients with metastatic epidural cord compression will have no known history of cancer 20% of the time.

Exam

Patients can be difficult to examine. If they can squat and walk on their toes and heels, they most likely have intact motor function. Sensation is likely intact if the patient has sensation to light touch over the anterior thigh (L2-L3), anterior knee (L4), dorsal foot (L5), and posterior leg (S1)

Consider an abdominal exam and/or bedside abdominal ultrasound. In a patient over 50 with risk factors for AAA and a history not consistent with other causes of back pain strongly consider a point of care ultrasound.

Labs

A patient with a normal ESR (less than 20mm/hr) and CRP (less than 1.0) is low risk for an epidural abscess. A normal ESR and CRP cannot exclude other causes of back pain such as central disc herniation or epidural hematoma.

Imaging

  • Plain films have little diagnostic utility and are insensitive. Postive x-rays are likely to need further advanced imaging
  • CT mainly used to assess for fractures
  • MRI is the diagnostic study of choice for serious causes of back pain

Scenarios 

The diagnostic approach should be individualized based on history, exam, and red flags.

Algorithm from Annals of Emergency Medicine

Case Approach
A patient with back pain with no neurologic symptoms and a normal neurologic exam. The patient is likely low risk and can be treated conservatively.
A patient with a history of IVDU whos back pain is worse with movement. Exam is normal, and he is afebrile. An ESR and CRP could likely be used to help assess for an epidural abscess. If negative, the patient can likely be treated conservatively with outpatient follow up.
A patient with a history of anticoagulation use and back pain that is worse when turning to the left. The pain started after moving boxes.  An ESR and CRP would not be helpful as the patient does not have risk factors for an epidural abscess. If the patient has no neurologic findings then discharge for an outpatient MRI is a reasonable approach.
A patient with a history of HIV and fever. A MRI is indicated in a patient who is febrile and immunocompromised. The patient is at risk for epidural abscess, vertebral osteomyelitis, and infectious discitis.
A patient with a history of steroid use and progressive back pain for the last 2 days. There is no history of back pain in the past.

Steroid use places the patient at risk for pathologic fracture and epidural abscess. ESR and CRP can be used to assess the need for MRI. For the evaluation of a possible fracture, a CT scan can be utilized.

 

 

A patient with a history of HIV and back pain radiating down the left leg. Patient afebrile with a normal neurologic exam

Patient is at risk for epidural abscess, but the history is consistent with sciatica. ESR and CRP could be used to determine the need for an MRI.

 

 

Emergency Medicine FOAM

Management of Non-traumatic Back Pain (Annals of Emergency Medicine Review Article)

Podcasts

Episode 26: Low Back Pain Emergencies

Episode 39.0 – Killer Back Pain

References

  1. Edlow JA. Managing nontraumatic acute back pain. Ann Emerg Med 2015;66:
    148–53
  2. Singleton J, Edlow J.A. Acute nontraumatic back pain: Risk stratification, emergency department management, and review of serious pathologies. Emerg Med Clin North Am 2016; 34: pp. 743-757

Pediatric Respiratory Emergencies

Foreign Body Aspiration

Patient In Severe Respiratory Distress

  • Alternate between 5 back blows and 5 chest thrust in infants
  • In school-aged kids perform Heimlich
  • If the patient becomes apneic/unconscious, perform laryngoscopy and attempt removal of the foreign body if visible

Surgical Airway in Children

Croup

Overview

  • Harsh barky cough with URI symptoms and stridor
  • Most common in winter months

Severity

Symptoms

Mild Stridor with agitation
Moderate Stridor at rest
Severe Severe stridor with respiratory distress

The Forgotten Diagnoses

Consider an alternative diagnosis in patients unresponsive to standard treatment for croup.

  1. Bacterial Tracheitis
  2. Foreign body aspiration
  3. Retropharyngeal abscess
  4. Epiglottitis

Treatment

  • All patients get dexamethasone 0.6 mg/kg IV or PO (IV formulation is also given PO)
  • Nebulized budesonide 2mg/2mL can be given as an alternative to dexamethasone
  • Patients with moderate to severe croup should be given 0.5 mL racemic epinephrine 2.25 %

In patients with clinical improvement after racemic epinephrine observe for 4 hours before discharge.

Bronchiolitis

Overview 

  • URI symptoms with ronchi, wheezing, or crackles on physical exam
  • Most common in patients less than 2 (wheezing is more consistent with bronchiolitis and not asthma in this age group)
  • Clinical diagnosis
  • Common from November to March

Treatment

  • Nasal suctioning
  • Oxygen therapy for patients with oxygen saturation less than 90%
  • Consider albuterol and/or dexamethasone PLUS racemic epinephrine in ill-appearing patients if other treatments have failed (limited evidence)

ASTHMA

Overview

  • Obstructive lung disease leading to bronchoconstriction and inflammation.

The Forgotten Diagnoses

The below diagnoses can be easily be overlooked.

  1. Anaphylaxis
  2. Foreign body aspiration leading to obstruction of lower airways

Treatment

Treatment Dose
Bronchodilators Give 0.5 mg/kg albuterol (2.5mg/3 mL). Most children can tolerate 15 mg. Albuterol is well tolerated and dosing does not have to be precise. Ipratropium 250 mcg in children less than 20 kg and 500 mcg in children greater than 20 kg. Total of 3 doses of ipratropium can be given
Steroids Sick: Methylprednisolone 1 mg/kg IV
Not Sick: Prednisolone 1mg/kg PO
Magnesium 50 mg/kg IV
Epinephrine Less than 30 kg = Infants give 0.15mg IM
Greater than 30 kg = School age give 0.3mg IM, ok to use approximate dosing for rapid resuscitation of sick asthmatics

Noninvasive ventilation

Despite medical therapy, children with severe respiratory distress may require respiratory support. In general continuous positive airway pressure improves oxygenation and  Bi-level positive pressure ventilation improves ventilation. For more details on noninvasive ventilation listen to the EMCRIT podcast.

Continuous positive airway pressure (CPAP) 

  • Start at 5 cm H2O and titrate to a max of 15 cm H2O

Bi-level positive airway pressure (BPAP)

  • Expiratory positive airway pressure (EPAP) starting at 5 cm H2O with a max of 15 cm H2O
  • Inspiratory positive airway pressure (IPAP) starting at 10 cm H2O with a max of 15 cm H2O

Emergency Medicine FOAM PoDCASTS

Breathe! Approach to the child who is short of breath. St.Emlyn’s

Episode 46.0 – Grand Rounds (Ilene Claudius) – Pediatric SOB

References 

  1. Shefrin A, Busuttil A, Zemek R. Wheezing in infants and children. In: Tintinalli JE, Stapczynski JS, Ma OJ, Yealy DM, Meckler GD, Cline DM, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: McGraw-Hill; 2016:(Ch) 124.
  2. Mapelli E, Sabhaney V. Stridor and drooling in infants and children. In: Tintinalli JE, Stapczynski JS, Ma OJ, Yealy DM, Meckler GD, Cline DM, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: McGraw-Hill; 2016:(Ch) 123.
  3. Nagler J, Cheifetz I. Noninvasive ventilation for acute and impending respiratory failure in children. Post TW, ed. UpToDate. Waltham, MA: UpToDate Inc.