1044 SECTION IX Pediatric Critical Care Hematology and Oncology symptoms ACS can progress in hours, is the second leading cause of hospitalization in SCD, and is the most common reason that children 1[.]
1044 S E C T I O N I X Pediatric Critical Care: Hematology and Oncology TABLE Management of Acute Chest Syndrome 88.2 Antibiotics A cephalosporin to cover encapsulated organisms, particularly S pneumoniae, and a macrolide, as Mycoplasma and Chlamydia are the most common infectious pathogens Oxygen Maintain saturations 94% Judicious fluid resuscitation Maintain euvolemia Avoid aggressive fluid resuscitation, as fluid overload may worsen cardiac and respiratory status Prevention of atelectasis • IS has been shown to prevent development of ACS Use IS or developmentally appropriate alternatives • Chest physiotherapy and ambulation may be of benefit once atelectasis and consolidation is present • BiPAP or CPAP as a preventive measure is untested but appropriate, as early intervention may prevent atelectasis and minute areas of collapse, preventing progression and the need for intubation Pain management Opiates should be carefully titrated to minimize splinting and allow IS while minimizing respiratory depression (small opiate boluses before IS may be helpful) Unfortunately, opiates are often withheld due to concerns of respiratory depression In fact, pain relief can improve respiratory mechanics, significantly improving clinical status Bronchodilators Are indicated, as asthma is common in sickle cell disease, and its presence increases the risk of ACS, and a subset of patients respond independent of documented wheezing Corticosteroids Use remains controversial, as they tend to improve ACS but lead to rebound pain Tapering of even pulsed steroids may reduce the rebound Transfusion For multilobar disease, worsening pulmonary status despite conservative methods of treatment, or those who are critically ill BiPAP or CPAP For worsening pulmonary status, clinical decline, or those who are critically ill Intubation and mechanical ventilation For those who fail noninvasive ventilation Consider inhaled nitric oxide if hypoxia Extracorporeal membrane oxygenation To be considered in those in whom mechanical ventilation and pharmacologic support are not sufficient ACS, Acute chest syndrome; BiPAP, biphasic positive airway pressure; CPAP, continuous positive airway pressure; IS, incentive spirometry symptoms ACS can progress in hours, is the second leading cause of hospitalization in SCD, and is the most common reason that children 12 years and older are admitted to the ICU.51 Mortality attributable to ACS is high, accounting for 25% of all deaths in SCD In children, the mortality rate from ACS is 1%, compared with 4% in adults, with most deaths in children occurring in those younger than years (see Fig 88.5).52 Risk factors include a history of asthma, high baseline hemoglobin concentration (Hgb), and low HbF Factors associated with mortality include a prior episode of ACS, development of respiratory failure within 48 hours of presentation, sepsis, and simultaneous presentation with pain.52 Etiologies vary by age with multiple etiologic factors often present and include bacterial infections with typical and atypical organisms, viral infections, and fat emboli, as well as pulmonary infarction and hemorrhage.53 In addition, a functionally based etiology is suboptimally controlled chest pain resulting in poor lung expansion and increased atelectasis that then leads to vasoocclusion and inflammation Plastic bronchitis is a frequent occurrence in ACS54 (eFig 88.13) Presentation CS frequently occurs to days into a VOE ACS should be A suspected when there is fever, chest pain, cough, or other pulmonary symptoms However, notably, there is no single pattern of signs and symptoms that predicts ACS, and up to 35% of patients will have a normal pulmonary examination.52,55 As a result, there should always be a low threshold to obtain a chest radiograph to rule out ACS Leukocytosis and significant drops in Hb and platelets are common.52 Significant morbidity is associated with ACS, including pneumothorax and empyema, and 14% of patients developed respiratory failure in one study.53 Risk factors for respiratory failure include (1) extensive lobar involvement, (2) platelet count less than 199,000/µL, and (3) a history of cardiac disease.53 Management Detailed care plans are presented in Table 88.2 and eFig 88.12, and management guidelines published by Howard et al provide a comprehensive approach to treatment.22,56 Management of ACS can be addressed in stages Although there are not many randomized controlled trials to guide care of ACS,57,58 suggestions for an approach to care are presented in Table 88.2 All patients should receive conservative care The use of steroids deserves special attention Although their use in ACS is controversial (see Table 88.2), due to the risk of rebound pain with steroid withdrawal a taper is indicated, even if only pulsed therapies are used (as in asthma or prior to extubation).59–61 Transfusion has been shown to significantly improve oxygenation and clinical status in ACS.22,53,56 Although transfusion is usually effective at reversing ACS, because of the risks, including alloimmunization, transfusion is not part of initial management unless the patient is severely ill Although 20% to 70% of patients with ACS are transfused, views differ on performing a simple transfusion targeting a posttransfusion Hgb of 10 g/dL or an exchange transfusion targeting the same Hgb while lowering the HbS to under 30%.22,52,53,56 Both approaches improve oxygenation and are safe and effective However, exchange transfusion requires exposure to more donors, is more time-consuming, requires specialized equipment and trained staff, and may require central access in this population with increased thrombotic risk Thus, a simple direct transfusion is recommended for most situations.22,56,62,63 The benefit of direct transfusion in patients with a high Hgb (.9 g/dL) is less clear, as a minimal number of red cells can be transfused and exchange may be more advantageous in this circumstance Noninvasive ventilation (NIV) lacks robust data to support its routine use but can be helpful for some patients.22,56 One small study determined that bilevel positive airway pressure (BiPAP) use was successful in staving off invasive mechanical ventilation,64 whereas another found improvement in gas exchange and respiratory rate but not in hypoxemia or patient comfort.65 Invasive ventilation will be necessary for a subset of patients who have 1044.e1 ACUTE CHEST SYNDROME Diagnosis Definition: A new infiltrate on CXR in a patient with sickle cell disease Monitoring Diagnostic (if not previously obtained) Fluids, nutrition, general care CBC, diff., Maintain platelet count “euvolemia.” and reticulocyte IV + PO 1–1.25 × Continuous count initially maintenance pulse oximetry and daily until More fluid is Consider improving (compare appropriate only if CR monitor with patient’s patient is dehydrated baseline values) or if insensible Record losses are increased daily input and CXR Repeat (e.g., persistent output and for clinical fever) weight deterioration looking for Incentive progression May spirometry × 10 need serial CXRs breaths q hr during the day Type and cross (0800–2200), if match (minor awake at night, and antigen matched if prior to all CXRs available, sickle negative, leukocyte Encourage depleted RBC) to ambulation, activity have blood available Obtain red cell extended phenotyping for sickle cell patients if not done previously (at a minimum type for RhD, Cc, Ee and Kell) Vital signs q 2–4 hr Blood cultures if T ≥38.3°C or history of recent fever Capillary or arterial blood gas and assessment by PICU team for severe illness Medications/treatments Discharge criteria Oxygen to maintain O2 saturation >93% Off O2 Ceftriaxone 75 mg/kg q 24 hr IV (Prophylactic penicillin may be discontinued while on broad-spectrum antibiotics.) Afebrile >24 hr and negative cultures for 24 hours (if applicable) Azithromycin 10 mg/kg PO ×1, then mg/kg PO qd days 2–5, or other macrolide antibiotic Good oral intake, able to take all oral medications including antibiotics Chest physical therapy if consolidation is present Adequate pain relief (if needed) Follow patient’s specific pain plan If not with oral analgesics available consider morphine 0.1 mg/kg IV q hr or 0.01–0.1 mg/kg/hr continuous Discharge instruction infusion or PCA for severe pain Alternative completed regarding analgesics (but not Demerol) may be used in home use of individual cases Adequate pain relief is incentive spirometry essential to avoid splinting and improve while on opiates respiratory dynamics (Splinting worsens Follow-up plans respiratory status) coordinated with Consider round the clock bronchodilators, hematology service especially if patient has history of wheezing CXR to establish or asthma Some patients benefit even if not new baseline in 2–3 clinically obstructed months Consider use of BiPAP or CPAP if not improving with routine measures Consider red cell transfusion for progressive respiratory decline despite incentive spirometry and #1–6 above Pain control and incentive spirometry are commonly underutilized Transfuse initially if severely ill a Simple transfusion to a HCT of 30% (no clear benefit to exchange transfusion) b Exchange transfusion for patients with progressive disease and a Hct >27% or lack of improvement >36 hrs post simple transfusion Target a Hct of 30% and Hb S or Hb S + C 93% Prescribe medication for seizures if present Prescribe medication for intracranial pressure if present Broad-spectrum IV antibiotics if febrile Discharge criteria Clinically and neurologically stable >24 hr after transfusions Afebrile >24 hr Hematology and physical therapy follow-up organized If applicable and not on broad-spectrum antibiotics, continue prophylactic penicillin Exchange transfusion or erythrocyte -apheresis to a Hct of 30% and HbS ≤30%; remove femoral or central venous catheter as soon as possible to reduce risk of thrombosis If exchange transfusion cannot be done acutely a simple transfusion with RBC to a Hct of 30% may be done but should be followed by an exchange transfusion when available Quantitative HbS after transfusion or at discharge • eFig 88.14 Clinical guidelines for acute stroke in sickle cell CBC, Complete blood count; CR, cardio- respiratory; CSF, cerebrospinal fluid; CT, computed tomography; diff, differential; ICU, intensive care unit; HCT, hematocrit; I O, intake and output; IV, intravenous; RBC, red blood cell; MRA, magnetic resonance angiography; MRI, magnetic resonance imaging (From Center for Children with Special Needs Sickle Cell Disease—Critical Elements of Care 5th ed Seattle: Seattle Children’s Hospital; 2012.) ... chest syndrome complicated by plastic bronchitis (Courtesy Dr Wendy Su.) CHAPTER 88 Hemoglobinopathies 1045 worsening respiratory failure despite attempts at NIV and optimal medical management... Stroke. Clinical guidelines for stroke (eFig 88.14) provide elements of a detailed care plan.22 This section focuses on acute, clinically apparent cerebrovascular accident (CVA) related to SCD;... discussed later).74,75 Patients with HbS/C disease and other compound heterozygotic states not have this significantly increased risk, although it may be higher than that in the general population