Interesting Case Rounds Rebecca Burton-MacLeod R5 (yikes!), Emerg Med July 5 th, 2007

Case 21M presents to ED c/o CP X ~4 hrs Retrosternal, radiated bilaterally Not pleuritic + SOB +nauseas; not dizzy, no palpitations Also c/o generalized abdo pain, and pain to bilateral thighs (present x2days)

History cont’d No previous similar episodes, but sometimes his legs “have pain” Pt moved from India about 2mos prior, ++ language barrier ! PMHx: “healthy” Meds: none Allergies: none

Further hx Questions ?

Physical exam HR 115, BP 128/72, RR 26, Temp 37.9, sats 92% r/a Pt ++ uncomfortable, tearful CNS—A+O CVS—N heart sounds, PPP Resp—lungs clear Abdo—generalized mild tenderness, no guarding, no rebound, + BS MSK—c/o ++ tenderness to palpation bilateral thighs; no erythema or swelling noted

Investigations ??

Investigations CXR EKG CBC, lytes, Cr

EKG

Bloodwork Hgb 77 Plt 185 WBC 31 Lytes, Cr N

“Have you ever been told you have anemia before?”…

Sickle cell disease Autosomal recessive disease Caused by substitution of valine for glutamine in Hgb beta-chain (Hgb S)

Sickle cell distribution

Sickle cell crisis Vaso-occlusive crisis Aplastic crisis Splenic sequestration Acute chest syndrome Infections

Case cont’d Pt received: IV N/S 1L bolus; 2x maintenance fluids IV morphine 5mg boluses to total of 20mg Oxygen by n.p.

Case cont’d Called back to see pt as noted to be ++SOB Sats now 85% on r/a Clinically—wheezes and crackles heard bilaterally on auscultation of lungs Temp now 38.7C ABG—on 8L O2: pH 7.24 /CO2 51 /O2 50; lactate 12

Any thoughts ?

Acute chest s/o Defined as: New infiltrate on CXR Associated with new symptoms (fever, cough, sputum production, dyspnea, hypoxia) Occurs in 50% of SCD pts; recurrent in 80% Preceded by vaso-occlusive crisis in half of patients Leading cause of death for pts with SCD

Risk factors for ACS Young Homozygous sickle-cell genotype Fever Winter months Surgery Previous ACS events AVN of bones High Hgb levels Low fetal Hgb levels High steady-state leukocyte counts

Pathophysiology Infection Fat embolism Thromboembolism Vaso-occlusive sickling erythrocytes Hypoventilation due to rib/sternal infarction and pain Hypoventilation due to narcotic administration Pulmonary edema due to fluid overload

Sign / symptoms ~25% of adults have other symptoms of pain (usually lower extremities)

Mgmt Identify and treat precipitating factors Maintain/improve oxygenation Prevent further alveolar collapse Maintain adequate fluid volume Control pain Treat underlying infection

Oxygenation Administer O2 to keep PaO2 ~ Pts may require simple, or exchange transfusions (allow removal of Hgb S) if severe anemia Incentive spirometry, CPAP, or intubation/ mechanical ventilation with PEEP

Indications for exchange tx Evidence of rapid clinical deterioration SaO2 <80% despite aggressive ventilatory support Serial decline in SaO2 Worsening/unstable vital signs Persistent RR >30/min

Maintain fluid volume Replenish dehydration with N/S For further fluid volume, use D5W/0.25N/S Hypotonic fluids preferred as allows water to enter RBC Causes osmotic swelling and reduced tendency for sickling

Treat underlying infection 2 nd -3 rd gen cephalosporin +/- macrolide Bacteremia in ~3.5% of cases of ACS Strep pneumoniae H. flu Staph aureus Salmonella Enterobacter Clostridia

Other therapies DBRCT of IV dex in peds (n=43) showed SS shorter hosp stays, dec blood transfusions, dec clinical deterioration Multiple case reports and animal studies of nitric oxide improving pt symptoms (lack of NO bioavailability in SCD) Poloxamer-188 (non-ionic surfactant) may shorten duration of ACS and length of hospitalization (n=43)

Questions ?

References Rosens Ballas SK, et al. Safety of purified poloxamer 188 in SCD. Hemoglobin Bernini JC, et al. Beneficial effects of IV dexamethasone in children with mild to mod severe ACS complicating SCD. Blood Gladwin MT, et al. The ACS in SCD. Am J Resp Crit Care Med Kararmaz, A et al. ACS in a patient with SC anemia successfully treated with erythrocytopheresis. Int J Emerg Inten Care Med Machado RF. Nitric oxide based therapies in SCD: the evidence continues to mount. Crit Care Med Vichinsky EP, et al. ACS in SCD: clinical presentation and course. Blood Yale SH, et al. ACS in SCD. Postgrad Med