MOC May 2015: Serious Curveball "Weakness with Visual Field Deficits"

Chief Complaint - Stroke Code: Weakness with Visual Field Deficits

31 y.o. male with pmhx of carotid artery dissection and pericarditis who presents to the Emergency Department for evaluation of possible stroke.

Stroke code called prior to arrival for right sided weakness and visual field deficit.  Pt arrived to the ED stroke neurologist at bedside.  Pt states unable to stand last night 2/2 weakness also ℅ left shoulder pain.

On arrival BP 78/48 pt ℅ decreased urine output and left sided abdominal pain.  Recently diagnosed with strep throat and started on amoxicillin.  He also continues to have generalized weakness without any focal deficits. Patient denies any monocular visual field deficits, focal weakness, black/bloody stools or emesis, or known sick contacts.

Of note, the patient had a right carotid dissection with left sided deficits three years ago for which he did not receive TPA and has since fully recovered.

Physical Exam:

First Vitals:

Temp: 97.6 °F (36.4 °C) BP: 78/48 mmHg Pulse: 112 Resp: 18 SpO2: 96 %

HEENT: Dry mm, pale

Cardiac: Tachycardic no murmur/r/g

Respiratory: CTAB

Abdomen: Soft diffusely tender, greatest LUQ tenderness

MS: MAEE, no TTP

Neuro: 2-12 intact, normal sensation B UPPER EXTREMITY/LE, MAEE, normal finger-nose-finger, visual field B deficit when sitting up, no visual field cut

Extremities: distal pulses intact

Psychiatry: Anxious

Bedside u/s as below

Istat creatinine is back at 2.9, SBP improved to 100 ~ 1L open fluids pt is taken to CT scan.  While you wait the following labs come back.

CBC 20.8>10.7<351
Chemistry 134/5.1/99/20/15/2.82 ALT 140 AST 103 INR 1.4 Lactic Acid 3.7 CT Chest Abdomen Pelvis WO: Splenomegaly with probable spontaneous rupture and pneumoperitoneum. CT Head Brain WO: Old right hemispheric infarct Medical Course Surgery and IR were consulted and the patient underwent successful coil embolization of the splenic artery on 3/29/2015. He was admitted to the ICU following the procedure. It was felt this was likely spontaneous splenic rupture from splenomegaly due to infectious mononucleosis The patient's Hgb dropped to 6.6 on the day following embolization and he received 1 U PRBC. His hgb stabilized in the 8-9 range. WBC remained elevated in the 15-20 range and plts rose as high as 927K.  He was seen by infectious disease and given recommendations regarding functional asplenia. He received vaccinations against pneumococcus, meningococcus, and Hib after 2 weeks. Mononucleosis Infectious mononucleosis is very common and caused by EBV.   Complications of Mononucleosis Splenomegaly and splenic rupture Spontaneous splenomegaly is seen in 50-60% of patients. Splenic rupture occurs in 0.06-0.5% and occurs spontaneously in ~50% of patients. Usually occurs between the 4th and 21st day of symptomatic illness.   Neurologic syndromes GBS Facial or cranial nerve palsies Meningoencephalitis Transverse myelitis Peripheral neuritis Optic neuritis Encephalomyelitis Treatment for uncomplicated mononucleosis with splenomegaly Supportive care Use of steroids has been controversial.  Double blind placebo trial 1996 looked at 94 patients with mononucleosis and gave acyclovir/prednisolone or placebo.  It did NOT affect duration of clinical symptoms or development of EBV cellular immunity Meta-analysis of Acyclovir in five randomized controlled trials show no benefit with Acyclovir over placebo. Return to sports More than 50% of patients develop splenic enlargement.  All athletes should refrain from sport activities during early illness.   Most ruptures occurs within 2-21 days after onset of clinical symptoms and rarely occur after the fourth week Some studies recommend ultrasound prior to return to contact sports.  Most practitioners use clinical judgement and return to training within three weeks from symptom onset and after 4-7 weeks for contact sports. Splenic Rupture Can be initially managed with observation, angiographic embolization or surgery depending on the hemodynamic status of the patient and grade of splenic injury.  Because the rarity of spontaneous splenic rupture no clear consensus of treatment has been reached.   Etiology: Acute increase in portal venous pressure caused by valsalva maneuver causing vascular engorgement.  Sudden compression of the enlarged spleen occurs from contraction of the diaphragm or the abdominal wall causing thinning capsule to rupture.   Treatment Hemodynamically unstable Requires IR ablation or surgery Embolization is contraindicated in patients >55 Retrospective multicenter trial with 1275 patients found angioembolization increased likelihood of splenic salvage More than 70% of patients with spontaneous splenic rupture ultimately undergo splenectomy Hemodynamically stable Observation, serial hemoglobin Thinking Errors Anchoring Bias - Deciding upon a diagnosis too early without adjusting to new information Availability bias - Thinking a similar presentation is happening in the current situation due to similarity Confirmation Bias - A tendency to search for or interpret information in a way that confirms your preconception.   The use of heuristics or protocols can be misleading if the initial diagnostic impression is wrong Diagnosis momentum - Accepting a previous diagnosis without appropriate data Overconfidence bias - Over assurance with one’s own ability and judgement Premature closure - Completing a case prior to receiving all the information Search-satisfying bias - A moment where you feel as though you figured out the answer without any further thought Almost all of these errors have an anchoring bias meaning we do not broaden our ddx and jump to conclusions. The busier we get the more important it is to step back broaden our perspective and use metacognition to reduce cognitive diagnostic errors. Key learning points: Hypotension + free fluid on ultrasound will require surgical or IR embolization Steroids and acyclovir do not improve symptoms from mononucleosis It is difficult to overcome the confirmation bias.  If something doesn’t fit (ie low BP) take a step back and broaden your Ddx Questions In the hemodynamically unstable patient with ruptured spleen what is the appropriate treatment: Fluid and blood products and observation Surgical or IR intervention with embolization Fluid hydration avoidance of blood products Acyclovir, steroids, and fluids What is the appropriate treatment for uncomplicated mononucleosis Steroids Acyclovir Acylovir + steroids Supportive care True or False: Splenic rupture can only occur with trauma. True or False: Confirmation bias can be overcome with taking a step back reevaluating the evidence and using metacognition. References Tynell E, Aurelius E, Brandell A, et al. Acyclovir and prednisolone treatment of acute infectious mononucleosis: a multicenter, double-blind, placebo-controlled study. J Infect Dis 1996; 174:324. Candy B, Hotopf M. Steroids for symptom control in infectious mononucleosis. Cochrane Database Syst Rev 2006; :CD004402. Thompson SK, Doerr TD, Hengerer AS. Infectious mononucleosis and corticosteroids: management practices and outcomes. Arch Otolaryngol Head Neck Surg 2005; 131:900. Kinderknecht JJ. Infectious mononucleosis and the spleen. Curr Sports Med Rep 2002; 1:116. Ali J. Spontaneous rupture of the spleen in patients with infectious mononucleosis. Can J Surg 1993; 36:49. Banerjee A, Duane TM, Wilson SP, et al. Trauma center variation in splenic artery embolization and spleen salvage: a multicenter analysis. J Trauma Acute Care Surg 2013; 75:69. Stephenson J, DuBois J. Nonoperative management of spontaneous splenic rupture in infectious mononucleosis: A case report and review of the literature.  Pediatrics 2007;432-435. Pines. Profiles in patient safety: confirmation bias in emergency medicine.  Acad Emerg Med 2006; 90-94.