Spotting the sick neonate - ED Perspective

Emergency Medicine is knowing "something about everything" in contrast to specialists who endeavor to know "everything about something". Therefore, as frontline physicians, we must know about common neonatal problems as well. 

While taking care of neonates, special attention needs to be paid to the adequacy of airway and breathing as they have limited compensatory reserves. As a rule, we should always consider early use of positive-pressure ventilation or endotracheal intubation for respiratory distress. Tachypnea in neonates can be very nonspecific as it may be due to underlying cardiovascular, respiratory failure or other systemic diseases. But as with everything else in EM, regardless of the cause, primary management remains similar i.e supporting ABCs. Here is a list of common life-threatening neonatal conditions:

Neonatal Sepsis (Pnemonia, Meningitis, Shock)

The height of the temperature does not distinguish a viral versus bacterial cause in neonates. Neonatal Sepsis is one of the most common causes of neonatal cardiorespiratory distress and most experts keep a low threshold for a full sepsis workup in neonates.  Fever in the first month of life is defined as rectal temperature ≥38°C, and hypothermia is rectal temperature <36.5°C (97.7°F). Early-onset sepsis (commonly septic shock) is seen in first few days and is usually associated with is usually associated with maternal or perinatal risk factors, such as maternal fever, prolonged rupture of membranes, and fetal distress. In contrast, late-onset sepsis (commonly meningitis) usually occurs after 7 days of birth and tends to develop gradually, with no predisposing risk factors. 

Clinical signs of early or late-onset sepsis in neonates are non-specific. They may demonstrate lethargy, irritability, seizures, tachypnea, grunting, hypo/hyperthermia, jaundice, rash, poor feeding, diarrhea, vomiting. Tachypnea and respiratory distress may be a sign of sepsis, meningitis, or urinary tract infection. Neck stiffness and other signs of meningismus may not be seen in neonates with meningitis. Common pathogens most frequently encountered in neonatal sepsis are gram-positive cocci (β-hemolytic streptococci) and enteric organisms (Escherichia coli and Klebsiella species, and Haemophilus influenzae). Other possible agents could be Listeria monocytogenes, viruses such as enteroviruses (coxsackievirus and echovirus), respiratory syncytial virus and influenza A virus. 

Work up includes FBC, CRP, Cultures, Urine Analysis, Renal Function, LFT and Coags and imaging as indicated. Admission and IV empiric IV antibiotics is a norm. The initial choice usually includes ampicillin (covers group B Streptococcus and Listeria) and an aminoglycoside (covers E. coli and other gram-negative organisms). Ceftriaxone is avoided in neonates as it can cause kernicterus. Use cefotaxime instead. Acyclovir is added for neonates with a maternal history of herpes or suspicious cerebrospinal fluid findings and all neonates who are ill appearing.


Congenital Heart Disease

Congenital heart defects that present with cyanosis include transposition of the great arteries, tetralogy of Fallot, tricuspid atresia, truncus arteriosus, and total anomalous pulmonary venous return. Acyanotic lesions include those that result in pulmonary overcirculation such as VSD, ASD, PDA and atrioventricular canal as well as those with restricted pulmonary or systemic blood flow such as pulmonary stenosis, aortic stenosis, and aortic coarctation.

Suspect congenital heart disease in any well-developed neonate who presents with unexplained cardiorespiratory collapse, cyanosis, and or tachypnea, especially without chest retractions or use of accessory muscles for breathing. Undiagnosed congenital heart disease may be first identified after discharge:

Day 7-14:  Lesions dependent on pulmonary or systemic blood flow through the ductus arteriosus (e.g., hypoplastic left heart syndrome, critical coarctation of the aorta) present with shock and acidosis as the duct begins to close. 
>Day 14: Lesions that involve left-to-right shunting of blood (ASD/VSD) typically present after the second week of life as pulmonary vascular resistance falls, allowing pulmonary overcirculation and the onset of congestive heart failure.

Neonates with cyanosis secondary to congenital heart disease rarely have respiratory symptoms other than tachypnea whereas neonates with lung disease producing cyanosis show respiratory distress, grunting, tachypnea, and retractions. The single most important therapeutic intervention for duct-dependent lesions is IV PGE1 to restore ductal patency. 

Bronchiolitis

Neonates with bronchiolitis present with nasal discharge and sneezing followed by diminished appetite, difficulty with feeds, cough, dyspnea, irritability, and, occasionally, periods of apnea. Respiratory symptoms include hypoxia, wheezing, retractions, and possibly palpable liver and spleen due to pulmonary hyperinflation. Factors associated with complications of bronchiolitis include prematurity, underlying pulmonary or congenital heart disease, initial oxygen saturation <92% and bronchiolitis caused by RSV.

Management remains supportive as in infants and toddlers. Antibiotics have no role in the management of bronchiolitis. CXR is done to rule out other causes of breathlessness. Bronchodilators may be tried but there is limited evidence to support their routine use. Adrenaline nebs may also be administered. There is conflicting evidence regarding the use of steroids. Full sepsis evaluation is done only if they appear critcially ill.

Airway Issues
Most of these anomalies are identified prior to discharge. 
Upper respiratory tract problems: choanal atresia, laryngomalacia, tracheomalacia, micrognathia, macroglossia, tracheoesophageal fistula, vascular slings
Lower respiratory tract: congenital lobar emphysema, sequestration, cystic adenomatous malformation, congenital diaphragmatic hernia

All these diagnoses should be considered in any infant with respiratory distress. Admission and work up is needed for diagnosis.

Neuromuscular Disorders

Muscle weakness in neonates may be associated with a compensatory increase in respiratory rate. Possible etiologies include Infantile botulism, Down’s syndrome; Hypoxic-ischemic encephalopathy,  Myelomeningocele, Spinal muscular atrophy, Myasthenia gravis, metabolic disorders and myotonic dystrophy.

Inborn Errors of Metabolism (IEM)

Since most metabolic toxins cross the placenta and are cleared by maternal enzymes, most newborns in-uterus are asymptomatic and present after enteral feeding begins. Sudden deterioration of a well neonate should always prompt consideration of metabolic diseases. Vomiting, altered mental status, hypoglycemia, ketonuria, poor feeding and cardiorespiratory distress are the most common clinical features of metabolic emergencies.  Hypoglycemia with negative urinary ketones suggests a fatty acid oxidation defect, and hypoglycemia with positive urinary ketones suggests organic acidemias. Reaching a precise diagnosis is often not possible in ED and management is limited to maintaining normoglycemia, supplementing fluids and electrolytes, blood gas analysis, checking serum ammonia levels and capillary ketone levels. Administer dextrose containing IV fluids for a suspected metabolic disease until specialty consultation can be obtained.  

Empiric therapy with arginine and sodium benzoate can reduce ammonia levels drastically. Early aggressive treatment may eliminate the need for dialysis.

Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia results from a deficiency in one of the five enzymes involved in the production of cortisol. It is one of the life-threatening endocrine emergencies that present in the neonatal period. Despite screening for this disorder, neonates may present in shock before screening results are known, typically in the first or second week of life. On examination, look for virilization, ambiguous genitalia, and hyperpigmentation. Hyponatremia and hyperkalemia occur in the salt-wasting form of congenital adrenal hyperplasia. ED management includes fluid resus with 10-20 mL/kg of normal saline, correction of hypoglycemia and administering steroids i.e. hydrocortisone 25mg IV/IM/IO, and urgent management of hyperkalemia. 

Image taken from http://what-when-how.com/acp-medicine/the-adrenal-part-2/

Avoid giving for treating hyperkalemia in an infant as this may result in profound hypoglycemia.

Intracranial and Intra-abdominal Hemorrhage

Birth trauma, NAI, and Vitamin K deficiency predispose to Intracranial bleed.
Neonates with abdominal distention, dehydration, bilious vomiting may have underlying congenital malrotation leading to midgut volvulus and bowel infarction. Necrotizing enterocolitis is classically seen in premature infants with poor feeding; abdominal distension, tenderness, and discoloration; lethargy or irritability; vomiting or diarrhea; temperature instability; apnea; and circulatory collapse. Other possibilities include testicular torsion and NAI.



References:
Tintinalli textbook of EM - 8th edition


Posted by:

              

     Lakshay Chanana

     

     Speciality Doctor

     Northwick Park Hospital

     Department of Emergency Medicine

     England

     @EMDidactic

Neonatal Problems - Part 2

Gastroesophageal Reflux and Vomiting 

Regurgitation of small amounts of milk or formula is common in neonates due to reduced lower esophageal sphincter pressure. Parents often confuse regurgitation with vomiting. Adequate weight gain in a baby with GER is reassuring but those who fail to thrive or have respiratory symptoms related to feeding should be investigated for anatomic causes of regurgitation. Reflux can be reduced with  thick feeds and feeding in upright position. Regurgitation with stridor and cough should be evaluated for anatomical defects. Potential causes of vomiting include tracheoesophageal fistula with esophageal atresia, GI obstruction or midgut malrotation, intussusception, necrotising enterocolitis  It may also be a symptom of sepsis, raised ICP, inborn errors of metabolism, incarcerated hernia. 

Diarrhea and Dehydration 

Neonates are susceptible to dehydration and electrolyte abnormalities associated with severe diarrhoea. Bloody diarrhoea may be a symptom of volvulus, intussusception, or necrotising enterocolitis. Abdominal distention may also occur in association with diarrhoea, bowel obstruction, constipation, necrotizing enterocolitis, or ileus due to sepsis. Obtain serum electrolytes, glucose, stool testing and a urine sample in the setting of fever to evaluate for UTI.

Blood in Diaper 

Potential causes include blood from genital tract in girls, anal fissure, swallowed maternal blood, coagulopathies, necrotizing enterocolitis, allergic or infectious colitis, congenital defects or idiopathic. A newborn with a single event of hematochezia and no concerning findings may be observed as an outpatient. Persistent symptoms or concerning exam findings should be further evaluated. 

Constipation 

Infrequent bowel movements in neonates do not necessarily mean that the infant is constipated. Infants occasionally may go without a bowel movement for 5 to 7 days and then pass a normal stool. However, if the neonate has never passed stools, especially if there has not been a stool in the first 48 hours of life, consider intestinal stenosis, Hirschsprung’s disease, or meconium ileus associated with cystic fibrosis. Neonates with constipation should have a careful evaluation of thyroid function and lumbosacral spine for evidence of occult neural tube defects. The diagnosis of Hirschsprung’s disease is supported by absence of feces on rectal examination, a tonic or tight sphincter tone, and an abrupt change in bowel luminal size on barium enema, and is confirmed by a rectal biopsy demonstrating absence of ganglion cells. 

Neonatal Jaundice

Jaundice signifies hyperbilirubinemia and can represent normal new-born physiology or a pathologic process. 

Physiologic jaundice is characterized by a slow rise in bilirubin (<5 milligrams/dL per 24 hours), with a peak of 5 to 6 milligrams/dL during the second to the fourth days of life and a decrease to <2 milligrams/dL by 5 to 7 days. Decreased neonatal hepatic glucuronyl transferase activity, a shortened life span of neonatal red blood cells and relative polycythemia, and decreased intestinal bacterial colonization all lead to an increase in enterohepatic circulation that produces the normal rise in bilirubin seen in physiologic jaundice. 

Breast milk jaundice occurs be due to the presence of substances that inhibit glucuronyl transferase in the breast milk; it may start as early as the third to fourth day and reaches a peak of 10 to 27 milligrams/dL by the third week of life. Cessation of breastfeeding is not routinely recommended. It is unlikely to cause kernicterus and usually can be treated with phototherapy, when necessary. 

Breast feeding (starvation) jaundice occurs when a newborn is exclusively breastfed and the mother’s milk supply is still inadequate. Poor oral intake leads to reduced bowel movement and less bilirubin excretion through the GI tract. Treatment is optimizing the neonate’s feeding pattern with supplementations or donated breast milk. Severe hyperbilirubinemia may require treatment.

Excessive hyperbilirubinemia can lead to permanent brain injury (kernicterus). 

Distinguishing between physiologic and pathologic neonatal jaundice is important, and the timing of the onset of jaundice in the newborn provides useful clues. 

Timing:
<24hrs - Congenital or Acquired  infections, ABO/Rh incompatibility, Hematoma (Cephal/IM)
2-3 days - Physiologic
3-7days - Congenital or Acquired  infections, CN Syndrome, Giblert's Syndrome
>7 days -  Acquired infection, Breast milk jaundice, Congenital or acquired hepatitis, Biliary Atresia, RBS membrane of enzyme defects, Metabolic (galactosemia, fructosemia)

Key questions to evaluate jaundice:

• Day of onset
• Blood group and Rh status
• Maternal infections during pregnancy
• Maternal blood type and RhoGAM® administration
• Color of stool 
• Fever
• Family history of hemolytic anaemia 
• Conjugate or Unconjugate Hyperbilirubinemia

Scleral icterus is typically noted with serum bilirubin >5 mg/dL. 

Unconjugated hyperbilirubinemia is much more common, presents earlier in the neonatal period, and is related to the normal or abnormal breakdown of hemoglobin, although inherited enzyme deficiencies or infection may be pathologic causes. Conjugated hyperbilirubinemia results from the inability to excrete bilirubin into the bile and intestines and is usually the result of primary hepatic or biliary disease such as biliary atresia or hepatitis. Conjugated hyperbilirubinemia is always pathologic and often presents later in the neonatal period with jaundice, acholic stools, and dark urine.

The treatment of hyperbilirubinemia depends on the cause, but for most cases of unconjugated hyperbilirubinemia, phototherapy is sufficient. For severe cases, exchange transfusion may be required. 

References;

Tintinalli's Emergency Medicine 8th edition

Posted by:

              

     Lakshay Chanana

     

     Speciality Doctor

     Northwick Park Hospital

     Department of Emergency Medicine

     England

     @EMDidactic

  

Neonatal Problems - Part 1

Emergency Department visits in neonates are often due to unclear and nonspecific symptoms. Subtle signs may not point to a specific illness. For instance, Respiratory, Cardiac, Abdominal and Metabolic pathologies can all cause respiratory distress. Many visits just need reassurance and understanding of what constitutes normal for a neonate but the key remains to differentiate benign symptoms from potentially life-threatening underlying disease.

Normal Neonatal Patterns

1. Feeding pattern are quite erratic in the few weeks of life. Breastfed infants take shorter and more frequent feeds (q1-3hrs) as compared to formula fed ones. Adequate Intake is considered if weight gain ranges between 20-30gms/day in the first three months. It is important to remember that neonates loose up to 12% (may be more in exclusively breast fed infants) of their body weight in the first week and are back to their birth weight by 15th day of life. 

2. Just like feeding, bowel movements also varies in number, colour and  consistency. 

Meconium (fist stool) is passed within the first 24 hours after birth. Color changes from black->dark green->yellow seedy by day 4. Failure to pass meconium in the first 48 hours of life may suggest Hirschsprung’s disease or cystic fibrosis.  Breastfed infants may occasionally go 5 to 7 days without a bowel movement. In contrast, overfeeding or use of formula that is too high in sugar content also can produce loose stools.

3. Normal respiratory rate in neonates is 30 to 60 breaths/min. Neonates increase minute ventilation almost entirely through an increase in respiratory rate rather than inspiratory volume. A resting RR >60 breaths/min requires evaluation. Observe respirations to determine if breathing is thoracic or abdominal. Since neonates are obligate nose breathers, even nasal congestion may cause respiratory distress. Periodic breathing (alternating periods of a normal/fast/slow rate with pauses of 3-10 seconds between breaths) is common in pre-term infants. Prolonged Apnea (>20 seconds) or apnea accompanied by bradycardia, cyanosis, or a change in muscle tone is abnormal and requires evaluation. 

4. Infants sleep pattern is fragmented ranging from from 20 minutes to 6 hours cycles spread throughout the day and night. By 6 months, most infants are sleeping through the night. It is important to look for any physical reason of unexplained nighttime cry. Benign causes of cry include Reflux, Wet or Soiled Nappies, Hunger, Too hot or too cold, Teething etc. Carefully look for other pathologies in an episode of acute, inconsolable crying. 

Crying

Inconsolable crying requires a thorough history and head-to-toe examination. Here is a list of illnesses presenting as crying. 

CNS: Intracranial Bleed (NAI, VIt K deficiency), Meningitis and Raised ICP
ENT: Choanal Atresia, Otitis Media, URTI
Eye: Corneal Abrasion, FB eye
CVS: Arrythmias, Heart Failure
RS: Pneumonia
GI: Oral Thrush, Stomatitis, Volvolus, Intussusception, Hernia, Anal Fissure, reflux, UTI, Diaper Rash, Gastroenetritis
GU: Testicular torsion, hair tourniquet, paraphimosis
MSK: NAI, Hair tourniquet 
Metabolic: Inborn errors, hypoglycaemia, Congenital Adrenal Hyperplasia 

If a careful history and complete physical examination does not reveal any source and the infant remains quiet during the ED observation period, reassure and advise follow up with the general practitioner. 

Colic: Unknown pathophysiology. Sudden onset of paroxysmal crying, a flushed face, circumoral pallor, tense abdomen, drawn up legs, cold feet, and clenched fists. Colic is defined as a paroxysm of crying for ≥3 hours per day for ≥3 days per week over a 3-week period. It is a diagnosis of exclusion. Rule out other sinister causes of irritability.

There is no specific treatment for colic and casual administration of drugs or sedatives is contraindicated. Colic creates immense stress among caregivers stress. 

Cough/Cold: Cough/Runny nose and Sneezing are usually due to Viral URTI. Neonates with underlying pulmonary or heart disease may develop respiratory failure with even mild URTIs. Check for ill contacts and perinatal infectious risk factors. Respiratory symptoms related with feeding might suggest reflux and aspiration or congenital tracheoesophageal fistula. Respiratory difficulty when quiet and improvement during crying suggest choanal atresia. Treat the underlying condition. Do not give cough suppressants to neonates. Treat nasal congestion with instillation of saline drops and bulb suctioning.

Abnormal Airway Sounds: May be related to benign problems. Distinguish between:

1.Stertor (snoring sound due to soft tissue vibrations in nasopharynx). Stertor can be a symptom of choanal stenosis which can be confirmed by inability to pass a small nasogastric tube through the affected nostril is diagnostic of this condition. 

2. Stridor (sign of upper airway obstruction, can be inspiratory or expiratory) commonly occurs due to laryngomalacia. Stridor may also be a symptom of congenital anomalies causing a fixed obstruction (webs, cysts, atresia, stenosis, clefts, and hemangiomas) anywhere from the nose to the trachea and bronchi. Stridor from fixed lesions is often biphasic. 

• Stridor worsening with cry: laryngomalacia, tracheomalacia, or subglottic hemangioma 
• Stridor accompanied by feeding difficulties: vascular ring, laryngeal cleft, or tracheoesophageal fistula. 
• Stridor with hoarseness or weak cry suggests vocal cord paralysis.
• Stride post intubation: maybe due to subglottic stenosis 
• Stride with fever: croup, epiglottitis, and abscess 

When the diagnosis is uncertain, admit for observation and evaluation. 

Periodic Breathing: Periodic breathing must be differentiated from apnea. Apnea is cessation of breathing for ≥20 seconds, or cessation of breathing for a period <20 seconds accompanied by bradycardia, cyanosis, or a change in muscle tone. It signifies critical illness and warrants investigation and admission for monitoring and therapy. Apnea usually indicates respiratory muscle fatigue and impending respiratory arrest. Provide airway and ventilatory support, and search for the cause. If no obvious cause is found, presume sepsis, obtain cultures, and initi- ate broad-spectrum antibiotics and acyclovir if there is concern for herpes simplex virus. 

Abnormal Movements: 

1. Benign sleep myoclonus: Rhythmic myoclonic jerks observed when the infant is drowsy or in quiet sleep and can be suppressed upon touching and/or waking the infant

2. Startle Reflex: Single myoclonic jerk with extension of the arms and legs triggered by noise or tactile stimulation.

3. Seizures: Present with subtle manifestations, such as eye deviation, tongue thrusting, eyelid fluttering, apnea, pedaling movements, or arching, rather than generalized activity. Neonatal seizures usually indicate a severe underlying structural or metabolic problem and are rarely idiopathic.

Eye Discharge: Clear eye discharge with crusting over the eyelashes without associated conjunctival redness or irritation, is commonly seen in neonates and infants and results from narrow or obstructed nasolacrimal ducts. This condition usually resolves sponta- neously and requires antibiotics only when complicated conjunctivitis or dacryocystitis. Ophthalmologic consultation in needed if problem persists past 12 months of age or  if associated with recurrent infections. Causes of Red Eye include Corneal Abrasion, Acute Glaucoma, Conjunctivitis (Gonococcal, Chlamydial, Herpes Simplex) 

References;

Tintinalli's Emergency Medicine 8th edition

Posted by:

              

     Lakshay Chanana

     

     Speciality Doctor

     Northwick Park Hospital

     Department of Emergency Medicine

     England

     @EMDidactic