1 / 25

Critical Care of Patients with Sickle Cell Disease

Critical Care of Patients with Sickle Cell Disease. James H. Hanson M.D. Director of Critical Care Children’s Hospital & Research Center Oakland Associate Clinical Professor of Pediatrics UCSF. Pathophysiology of Sickle Hemoglobin. Hemoglobin SS Hemoglobin SC Hemoglobin S- b thal

chars
Download Presentation

Critical Care of Patients with Sickle Cell Disease

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Critical Care of Patients with Sickle Cell Disease James H. Hanson M.D. Director of Critical Care Children’s Hospital & Research Center Oakland Associate Clinical Professor of Pediatrics UCSF

  2. Pathophysiology of Sickle Hemoglobin • Hemoglobin SS • Hemoglobin SC • Hemoglobin S-bthal • abnormal red blood cell cytoskeleton • hemoglobin polymerization • impaired red cell deformability • impaired microvascular flow • increased endothelial activation

  3. Acute Chest Syndrome • Pulmonary infiltrates • sometimes with effusion • with one or more of the following: • Chest pain • 40% also have abdominal pain • Fever • Impaired oxygenation • May also have chills • Often preceded by vaso-occlusive crisis • high phospholipase A-2 levels

  4. Acute Chest Syndrome • intravascular clogging • fat embolism • atelectasis • infection • thromboembolism

  5. Infectious Causes • Staph aureus • Strep pneumoniae • Hemophilus influenzae • Klebsiella pneumoniae • Chlamydia • Mycoplasma • Viral most common

  6. Vicious Cycle • sickling worsens with hypoxemia, acidosis • atelectasis causes vasoconstriction • sluggish flow and more occlusion • chest pain causes splinting • underaeration and atelectasis • narcotics for pain may decrease ventilation • increased atelectasis • increased PaCO2 increases acidosis

  7. Co-morbidities • asthma • marked anemia • thrombocytopenia • pulmonary hypertension • cor pulmonale

  8. One thing leads to another • acute chest syndrome often recurs • gradual scarring • restrictive lung disease • pulmonary hypertension • even without overt acute chest episodes • cor pulmonale • 20% of patients with ACS develop neurologic complications (often beginning with confusion)

  9. Therapy of Acute Chest Syndrome • Oxygen • avoid excess which reduces erythropoiesis • Careful rehydration • maintain euvolemia • judicious use of furosemide often helpful • Antibiotics • erythromycin or azithromycin • cefuroxime • Pain control • narcotics • ketorolac • acetaminophen

  10. Therapy of Acute Chest Syndrome • Improve oxygen delivery • reduce % hemoglobin S • packed red cell transfusion – early on! • exchange transfusion if still worsening (rarely needed if transfused early) • bronchodilators • albuterol regardless of presence or absence of wheezing • non-invasive ventilation • endotracheal intubation • adequate PEEP • incentive spirometry

  11. Therapy of Acute Chest Syndrome • Dexamethasone may shorten course • However, use of steroids associated with: • 1/3 of patients are readmitted • Increased risk of avascular necrosis • Pancreatitis • Mental status changes • Clinical trial being designed

  12. Therapy of Acute Chest Syndrome • Unproven therapies, but “seem to work” • Dornase alfa inhaled • Nitric oxide • ECMO

  13. Cerebral Vascular Accident • 300X > control patients without sickle cell disease • 11% with HgbSS will have CVA by age 15y • 2% of patients with HgbSC • 17-22% of Hgb SS patients have “silent” CVAs • Abnormal MRIs in 1/3 of patients by age 15 • Abnormal transcranial Doppler:  risk •  risk if baseline Hgb low or WBC high • Higher risk if BP normal to high • Higher if patient has moya-moya collaterals • Strokes reduced with chronic exchange transfusion • keep % Hgb S < 30

  14. Cerebral Vascular Accident • Standard management of airway, breathing, and circulation • More concern about hyperosmolar therapy • could induce more sickling • Transfuse and/or exchange to keep HgbS < 30% and Hgb 10-11 mg/dL • Avoid extremes of blood pressure • Normal BP is lower in sickle cell patients • Avoid hyperglycemia

  15. Splenic Sequestration • 15% of Hgb SS patients between 6-36 months • Rapid enlargement of spleen • Drop in hemoglobin • Rise in reticulocytes • Drop in platelets • Shock • Hemoglobinuria and renal failure • Liver sequestration rare • Rhabdomyolysis rarely

  16. Splenic Sequestration • Support intravascular volume • Pain control • Transfusion and rarely exchange • Splenectomy if recurrent or refractory • Immunize to pneumococcus; meningococcus • When liver involved, may need vitamin K • Closely monitor urine output

  17. Sepsis • Chronic penicillin or amoxicillin is indicated due to functional asplenia • Assure pneumococcal vaccination • Follow Surviving Sepsis Campaign guidelines

  18. Iron Overload • Results from > 20-30 units PRBCs • Desferoxamine (or deferiprone) for iron chelation • Cardiac dysfunction and CHF • Pancreatic disease and diabetes mellitus (no DKA) • Hepatic dysfunction • hepatocellular carcinoma • Hypothalamic pituitary dysfunction • sex hormone deficiency

  19. Iron Overload • Manage organ dysfunction as usual • Continuous desferoxamine infusion • Deferiprone (L1) available in many countries - may help • Other newer agents becoming available • May be eligible for solid organ transplant

  20. Transfusion • Preoperative transfusion to Hgb 9-10 gm/dl improves morbidity • Avoid Hgb > 12 gm/dl (hyperviscosity) • Sickledex negative blood • Phenotypically match, at least to C, E, Kell • high rate of alloimmunization • Leukodepleted blood

  21. Exchange transfusion • Use only if straight transfusion inadequate • Pheresis machine preferable • Manual exchange acceptable • dilute PRBCs with 5% albumin or NS to Hct 30 • monitor vital signs closely • May need calcium • 150 mL/kg removed and replaced (“double volume”) should reduce %S to < 30% • Blood exposure precautions • Use blood warmer

  22. Priapism • Painful, prolonged erection • Difficult to treat • Hydration, but not excessive • Narcotics • Transfusion not usually successful • Urologic injection/aspiration • Erectile dysfunction common sequela • especially in older patients

  23. Future directions • Sildenafil reduces pulmonary hypertension • improves exercise endurance • Gardos channel blockers (not yet available) • improve intraRBC dehydration • improve markers of hemolysis • Arginine + hydroxyurea improves available nitric oxide, and may help vasculopathy

  24. Hematopoietic Cell Transplant • BMT or other stem cell transplant can be a curative therapy for SCD • About 90 % survival • About 80% disease-free survival • Gonadal dysfunction • Minority have progression of lung disease • if prior lung disease present • Best candidates those who have had mild cerebrovascular accidents • Best outcomes in minimally-transfused • But how do you predict who is at risk?

  25. Perioperative Management • Preoperative transfusion improves morbidity • Highest risk of acute chest syndrome in first 48 hours after surgery • Outpatient surgery may be ill-advised • Better outcomes with laparoscopy

More Related