(This article is based on a case posed by Dr.Celeste Maycock,a real advocate of academic excellence)
As per definition this neonate fit in ALTE ( Acute Life Threatening Event). ALTE is subjective to care provider but it is important enough to be careful in managing this type of case as well as it is paramount to document care fully. Let us understand component of ATLE:
Frightenning to parents or care provider
blue (cynosis)
limping (loss of tone)
choking (unable to breath)
So this is a case of ATLE
Pt. came : need Red card inside : to be directed to ER: immediate vitals including RBG and SpO2
While looking at neonate place to medium flow oxygen,Monitor Airway, breathing, circulation (ABCs) with respiratory compromise, establish an airway & provide supportive therapy (e.g., oxygen, mechanical ventilation) Monitor Vital signs
- Establish vascular access for sampling blood ):
- If sepsis is suspected or another specific cause is not identified, start on broad spectrum antibiotics (e.g., ampicillin and gentamycin) after obtaining a CBC, urinalysis, blood & urine cultures (if possible). Left untreated, sepsis may lead to pulmonary disease & left ventricular dysfunction.
- Administering meds (if needed. kept on talking with mother and get all information from the mother ante natal,perinatal including baby's last 2 week (for this case):
Now go for differential one by one for each component of ALTE
CYNOTIC:
Pregnancy HX ___> Associated causes of cyanosis
- Gestational diabetes mellitus (GDM) -->TTN (ransient tachypnea of the newborn) (, RDS, hypoglycemia, TGA
- Oligohydramnios-->Pulmonary hypoplasia
- Pregnancy induced hypertension -->IUGR, polycythemia, hypoglycemia
- Lithium intake (1st trimester)--->Ebstein’s anomaly
- Advanced maternal age->Trisomy 21 associated with many congenital heart defects (cyanotic and acyanotic)
Labour Hx----> Associated causes of cyanosis
- PROM, fever, GBS +ve -->Sepsis
- Sedatives/anesthetics--->Respiratory depression, apnea
- C-section -->TTN, PPHN (persistent pulmonary hypertension of the newborn)
- Preterm infant-->RDS
- Meconium-->MAS (pneumonia)
YOUR DIFFERENTIAL STARTS HERE......MOTHER's HX FIRST
Do thorough Physical examination: I always consider dealing with neonate is almost a vetrenary practice: Neonate doesnot say any thing.
Look at the neonate differentiate cynosis is whether peripheral or central
Look at the vitals,
1/signs of respiratory distress : tachypnea, retractions, nasal flaring & grunting usually indicate a respiratory problem
2/Congenital heart disease : absent or effortless tachypnea.
3/Sepsis often has the following findings: peripheral cyanosis, HR, Increase RR, Decrease BP, Increase/Decrease temp (DDX: left-sided obstructive lesions: hypoplastic left heart syndrome, critical aortic stenosis & severe coarctation of the aorta).
4/Rule out choanal atresia. If in doubt, attempt to insert a catheter through the nares
Listen for murmurs: a systolic murmur audible in most forms of cyanotic CHD (exception: d-TGA with intact ventricular septum & no pulmonary stenosis).
Assess the abdomen: scaphoid abdomen in diaphgragmatic hernia
Consider neurological disorders: observe for apnea and periodic breathing, which may be related to immaturity of the nervous system. Seizures can cause cyanosis if the infant fails to breathe during the episodes.
Tracheal atresia with tracheooesophageal connection can give cynosis with feeding effort.
Here it becomes imperative to think about the various mechanism of cyanosis. Then, organize your thoughts by anatomical systems.
Ventilation/perfusion mismatch : delivery
- Airway disease: transient tachypnea of the newborn (TTN), respiratory distress syndrome (RDS), pneumonia, aspiration (meconium, blood, amniotic fluid), atelectasis, diaphragmatic hernia, pulmonary hypoplasia, pulmonary hemorrhage, CCAM
- Extrinsic compression of the lungs: pneumothorax, pleural effusion, hemothorax,
- Intracardiac: The 5 T’s: Tetralogy of Fallot, Tricuspid atresia, Transposition of the great arteries, Total anomalous pulmonary venous return, Truncus arteriosus; and pulmonary atresia, Ebsteins anomaly (abnormal tricuspid valve), hypoplastic left heart (shunts)
- Great vessel level: persistent pulmonary, hypertension of the newborn
- Intrapulmonary level: pulmonary arteriovenous malformation
Alveolar Hypoventilation
- CNS depression: asphyxia, maternal sedation, intraventricular hemorrhage, seizure, meningitis, encephalitis
- Airway obstruction: choanal atresia, laryngomalacia, Pierre Robin syndrome
- Neuromuscular disease: phrenic nerve inury, neonatal myasthenia gravis
Diffusion Impairment
- Pulmonary edema: left-sided obstructive cardiac disease (aortic stenosis), cardiomyopathy
- Pulmonary fibrosis
Decrease Hemoglobin O2 affinity
- Methemoglobinemia (congenital, drugs)
Decrease Peripheral circulation (peripheral cyanosis)
- Sepsis, shock of any cause, polycythemia, hypothermia, hypoglycemia, low cardiac output (hypocalcemia, cardiomyopathies, etc)
Investigation:
CBC
Increase or decrease WBC : sepsis
- Hematocrit > 65% : polycythemia
Serum glucose:
Arterial Blood Gases (ABGs):
- Arterial PO2: to confirm central cyanosis : SaO2 not as good an indicator due to Increase fetal Hb affinity for O2 (left-shift)
- Increase PaCO2: may indicate pulmonary or CNS disorders, heart failure
- Decrease pH: sepsis, circulatory shock, severe hypoxemia
- Methemoglobinemia: Decrease SaO2, normal PaO2, chocolate-brown blood
Hyperoxia test:
- Administer 100 % oxygen for > 10 min
- PaO2 > 100 mmHg: pulmonary disease likely
- PaO2 < 70 mmHg, rise by < 30 mmHg or SaO2 unchanged: cardiac cause (R-L shunt) likely
- Total anomalous pulmonary venous return may respond
- Pulmonary disease with a massive intrapulmonary shunt may not respond
Pre-ductal & Post-ductal PaO2 or SaO2 measurements (pre- and post- ductus arteriosus):
- Preductal artery (right radial) PaO2 10 – 15 mmHg > post ductal artery (umbilical artery line) PaO2 : R – L ductal shunt (e.g., pulmonary diseases, commonly PPHN)
- SaO2 can also be measured (right hand & right or left leg) : significant if > 10-15 % difference.
CXR
To identify pulmonary causes of cyanosis: pneumothorax, pulmonary hypoplasia, diaphragmatic hernia, pulmonary edema, pleural effusion, etc.
- Useful in evaluating congenital heart disease: e.g., cardiomegaly & vascular congestion: heart failure
- TGA : egg-on-a-string (anterior/posterior relationship of great vessels)
- TOF : boot-shaped heart (RVH)
- TAPVR : snowman, figure 8 (anomalous drainage chamber in superior mediastinum)
Echocardiography
- Indicated if abnormal cardiac examination suggestive of congenital heart defect, failed hyperoxia test (cardiac disease suspected) or has unclear diagnosis
- An infant who fails the hyperoxia test & does not have PPHN or a CXR showing pulmonary disease likely has a congenital heart defect that’s ductus-dependent.
Limping neonate:
now we have to look into hypotonia of the neonate. At least 35 to 40 differnt conditions can give limp (hypotonia) of muscle but we need to focus which also cause limping.
Seizure, hypoglycaemia, sepsis etc.
Hypotonia in Neonate and Infants:
Hypotonia is reduced resistance to passive movement of joints. The deficit causing hypotonia originate in the brain, spinal cord, peripheral nerves, neuromuscular junction, and muscle. There are also non-neuromuscular entities that may be associated with hypotonia including:
1. Prematurity
2. Hypothyroidism
3. Rickets
4. Malnutrition
5. Kernicterus
6. Storage diseases
7. Down Syndrome
8. Sepsis
9. Congestive Heart failure
10. Hypoglycemia
The differential diagnosis of hypotonia is organized anatomically in to central and peripheral causes. Peripheral hypotonia is further divided into disorders of anterior horn cells, peripheral nerves, neuromuscular junction, and muscle. In general, a good history, physical examination, and neurologic exam will lead to the diagnosis.
Characteristicshypotonia (60-80% of cases)
History:
· Seizures
· Delay in attaining normal milestones
PE:
· Don’t track visually
· Fail to imitate facial gestures
· Lethargic and less alter
· Hyperactive DTRs, clones, persistence of primitive reflexes
· Poor head control
Characteristics of Peripheral Hypotonia (15-30% of cases)
History:
· Normal sleep-wake patterns
· Feeding difficulties
PE:
· Responds appropriately to surroundings
· Profound generalized weakness
· Absent reflexes
Central Hypotonia
Hypoxic encephalopathy (19% of cases)
Intracranial hemorrhage
Perinatal trauma
Infections – meningitis or encephalitis
Structural abnormalities
Chromosomal and Genetic abnormalities (31%)
· Tiresome 21 (Downs Syndrome)
o Characteristic features: hypotonia, mental retardation, and congenital heart defects
o Dysmorphic features present in neonates: flat facial profile and nasal bridge, short neck with excess uncial folds, single transverse palmer crease, upslanting palpebral fissures
· Fragile X
o Genetic defect: expansion of trinucleotide repeat (CGG) on X chromosome
o Hypotonia is mild and kids are usually diagnosed after failure to meet developmental milestones
o Characteristic features: mental retardation, autistic features, macrocephaly, large ears, increased testicular size in puberty
· Prader-Willi syndrome:
o Characteristic features: hypotonia, hypogonadism, mental retardation, short stature, and obesity
o Genetic defect: deletion of paternal copy of long arm of chromosome 15q11-13 or maternal uniparental dismay
Now we have differential for both" blue" and "limp" baby , common are hypoglycaemia, sepsis, seizure, structural abnormalities... so we need some more data from the docket....proper vitals including Spo2 & RBG further CBC and routine blood work will help, clinically detailed resp and cvs examination data are important, reflexes should be noted,-----IMPLY PROPER Examination
and documentation.
