Pediatric emergency medicine trisk 633

lesions causing congestive heart failure Skeletal abnormalities, hand and arm in particular, can be associated with cardiac malformations Distinguish cool mottled distal extremities due to coarctation from cutis marmorata, a normal mottling in infants that appears with exposure to cold In many cases of cardiac disease, the breath sounds will be normal and typical signs of respiratory distress absent However, infants with left-sided obstructive disease and total anomalous pulmonary venous return can present with grunting, retractions, and tachypnea In either cardiac or respiratory distress there can be reduced oxygen saturations A hyperoxia test, using arterial blood gas analysis while 100% oxygen is supplied at a bedside, can be performed to distinguish between cardiac and pulmonary causes of cyanosis The neonate with cyanotic heart disease has little response to supplemental oxygen, whereas in pulmonary disease the increase in saturation may be dramatic In practice, an increase in PO2 to more than 220 mm Hg would suggest respiratory disease; 100 to 220 mm Hg would require evaluation for cyanotic CHD; less than 100 mm Hg would suggest cyanotic CHD, and marked cyanosis less than 40 to 50 mm Hg would be likely to have a poor mixing disease such as transposition of the great arteries If the hyperoxia test reveals positive or borderline results, immediate further evaluation for cyanotic CHD by the pediatric cardiologist is needed Chest radiographs should be obtained to rule out pulmonary disease as well as to evaluate for pulmonary vascular markings, cardiomegaly, and characteristic features found with some CHD—as in a “boot-shaped heart” seen with tetralogy of Fallot (TOF) The assessment of cardiomegaly requires both an AP and lateral chest radiograph and adequate inflation of the lungs Electrocardiogram (ECG) and echocardiogram should be obtained Because sepsis and myocarditis are on the differential of neonates presenting with symptoms of CHD, CBC, blood culture, urinalysis, and urine culture should be obtained Consider lumbar puncture in light of clinical examination and history and the overall stability of the patient Management Airway management is always of primary concern If the neonate is in respiratory distress, establish a secure airway and maintain adequate oxygenation Intubation with sedation and paralysis may reduce cardiac demand significantly Neonates with hypotension require fluid and resuscitation and possibly inotropic support with dopamine or dobutamine Neonates with strong clinical suspicion for ductaldependent CHD should receive prostaglandin E1 (PGE1 ) infusion in advance of a definitive diagnosis PGE1 is the standard medical intervention in neonate with duct-dependent lesions PGE1 relaxes the ductus and allows ongoing critical shunting of blood from left to right or right to left, depending on the cardiac lesion The initial intravenous dose of PGE1 is 0.01 mcg/kg/min in neonates with echocardiographic confirmation of a large patent DA to prevent closure and maintain ductal patency If the size of ductus is unknown or the ductus is restrictive, the starting dose is 0.05 mcg/kg/min If no improvement, the dose can be increased incrementally to a maximum of 0.1 mcg/kg/min After the infant’s condition has stabilized, the usual maintenance dose is 0.025 mcg/kg/min Apnea, bradycardia, hypotension, fluid–electrolyte imbalances, irritability, fever, and cutaneous flushing are potential complicating side effects of PGE1 The physician should have all intubation equipment readily available because apnea can occur at any time during infusion A second intravenous catheter should also be in place to provide resuscitative fluids as necessary Consult immediately with a cardiovascular specialist and transfer to a facility with pediatric cardiac expertise NEONATAL RESPIRATORY AND AIRWAY PROBLEMS Goals of Emergency Care Acute airway obstructions and respiratory distress in neonates can cause swift respiratory deterioration The neonatal airway has distinct features that predispose it to occlusion more frequently than children and adults Additionally, neonates have very low respiratory reserve (e.g., intubation attempt should only be attempted for 30 seconds before cardiovascular instability ensues) and high metabolic demands Rapid evaluation and diagnosis of acute life-threatening conditions necessitates an understanding of the different etiologies and coexisting medical problems Respiratory distress caused by nonrespiratory causes (such as cardiac lesions, metabolic acidosis, and neonatal sepsis) should be differentiated from those caused by airway and lower respiratory disease Stabilization of the airway and breathing is a priority There should be appropriate equipment and experienced personnel capable of urgently establishing an airway in a neonate Treatment is aimed at rapid recognition to prevent secondary morbidity KEY POINTS Neonates with respiratory distress or stridor can deteriorate very rapidly Always triage urgently Premature infants with bronchopulmonary dysplasia who develop acute respiratory distress will need admission Intubation attempts in a newborn should be limited to 30 seconds to prevent iatrogenic complications RELATED CHAPTERS Signs and Symptoms Apnea: Chapter 14 Cyanosis: Chapter 21 Respiratory Distress: Chapter 71 Septic-Appearing Infant: Chapter 73 Stridor: Chapter 75 Medical, Surgical, and Trauma Emergencies Cardiac Emergencies: Chapter 86 Infectious Disease Emergencies: Chapter 94 Pulmonary Emergencies: Chapter 99 Diseases That Cause Stridor in a Neonate Goals of Treatment Stridor is the most common symptom of congenital anomalies of the airway in a neonate Clinicians need to rapidly identify conditions that are life threatening and differentiate them from benign etiologies The primary goal should be quick triage and stabilization Supraglottic lesions (e.g., laryngomalacia) usually present with coarse inspiratory stridor whereas tracheal lesions (e.g., tracheomalacia and vascular rings) may present with expiratory stridor or wheezing Infants with glottic or subglottic lesions (e.g., vocal cord paralysis, papillomas, laryngeal web, subglottic hemangiomas, and subglottic stenosis) can have a biphasic musical type of stridor These sounds of stridor can be difficult to differentiate clinically Other symptoms such as cough, cyanosis, and feeding difficulties should also be elicited in the history All neonates with stridor should be assessed for a stable airway, signs of respiratory distress (tachypnea, tachycardia, retractions, cyanosis, and agitation), CO2 retention or aspiration, and placed on continuous pulse oximetry and oxygen to maintain saturations above 95% Blood gas to assess ventilation should also be considered Those with significant stridor may need respiratory support (high-flow humidified nasal cannula, continuous positive airway pressure [CPAP], or intubation and mechanical ventilation) If the airway is unstable, there should be appropriate equipment and personnel experienced in management of a neonatal airway The neonatal larynx has multiple features that are different from that of older children These predispose neonates to very rapid deterioration in respiratory status and can make endotracheal intubation challenging In addition to the smaller size, less than one-third of the adult size larynx, the position of the larynx at birth is higher (C4 rather than C7 in children) The epiglottis is longer and omega shaped Lastly, the cartilage is softer than that of older children, which is thought to contribute to the collapsibility of the laryngeal airway Additionally, neonates have very low respiratory reserve and high vagal tone; each intubation attempt should be preceded by preoxygenation and should not last longer than 30 seconds Vagolytics such as atropine should be given prior to intubation to prevent reflex bradycardia and promote cardiac stability Obtaining an airway film may help in differentiating etiology (e.g., subglottic stenosis, retropharyngeal abscess, soft tissue tumors compressing airway, or congenital cysts) A chest radiograph may also help if there is a suspected pulmonary component Obtaining a blood gas (if possible) helps with assessment of hypoxia and carbon dioxide retention All newborns with respiratory instability should be admitted to an intensive care unit In newborns with significant airway anomalies, surgical consultation is indicated Chapter 75 Stridor , further discusses the diagnosis and management of children with stridor CLINICAL PEARLS AND PITFALLS ... cardiovascular specialist and transfer to a facility with pediatric cardiac expertise NEONATAL RESPIRATORY AND AIRWAY PROBLEMS Goals of Emergency Care Acute airway obstructions and respiratory