Cyanosis in newborns
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Ifeoma Anaya, M.D.[2]
Synonyms and keywords:
Overview
Cyanosis is coined from the word kuaneos which is greek for dark blue. It is classified into two major types: peripheral and central cyanosis. Cyanosis results when there is an increase in the absolute concentration of deoxygenated hemoglobin to a level of 3-5g/dl. A systematic way of classifying the common causes of cyanosis in newborns is by using the ABC which stands for Airway, Breathing, and Circulation.
Historical Perspective
- Cyanosis is coined from the word kuaneos which is greek for dark blue. This is as a result of the bluish discoloration of the skin or mucous membranes depending on etiology. [1]
Classification
- Cyanosis is classified into two major types:[2]
- Peripheral Cyanosis (acrocyanosis) which is located on the hands and feet. It is mostly physiological and relatively common.
- Central cyanosis which is considered to be pathological and requiring immediate evaluation until proven otherwise.
Pathophysiology
- Central yanosis results when there is an increase in the absolute concentration of deoxygenated hemoglobin to a level of 3-5g/dl. Deoxygenated hemoglobin is dusky blue or purple which gives rise to the discoloration seen in skin and mucous membranes compared to bright red oxyhemoglobin.[1]
- Oxygen is transported in blood predominantly as bound to hemoglobin while an insignificant amount is transported dissolved in plasma. Sufficient tissue perfusion is largely dependent on the concentration of saturated hemoglobin.
- In the setting of high hemoglobin concentrations (normal relative polycythemia, 14-20g/dl) seen in normal infants, cyanosis becomes apparent at higher PaO2 (partial pressure of oxygen) compared to the setting of severe anemia where a much lower PaO2 would result in clinically recognizable cyanosis due to very low hemoglobin concentration. Therefore, cyanosis is a factor of the concentration of deoxygenated hemoglobin and not merely oxygen saturation. For example, a neonate with a hemoglobin concentration of 24g/dl exhibits signs of central cyanosis at 88% arterial saturation (SaO2) while cyanosis is not clinically obvious in an anemic infant until SaO2 falls to about 62%. [1] [3]
- Fetal and adult hemoglobin possess different capabilities of oxygen binding. If a newborn has mostly adult hemoglobin, cyanosis would be observed at a higher PaO2 of 42-53mmHg corresponding to SaO2 of 75%-85% compared to predominantly fetal hemoglobin(PaO2 of 32-42mmHg); infants have varied proportions of adult and fetal hemoglobin. Therefore, a serious reduction in PaO2 would have set in before cyanosis becomes apparent in a newborn with high levels of fetal hemoglobin, a setting that shifts the oxygen dissociation curve to the left. [3]
- Several changes occur in the newborn as soon as the first breath is taken. Blood flow resistance decreases in the pulmonary vasculature as a result of the increase in oxygen tension; this increase in oxygen tension and pulmonary circulation causes functional closure of the patent ductus arteriosus. Also, the foramen ovale closes from raised left atrial pressures. The events leading to the closures of these shunts invariably abolishes the right-to-left shunts of the fetal circulation. The first breath also causes a net absorption of the fluid from the respiratory system which expands the lungs and in turn initiates gaseous exchange. Furthermore, removal of the low-pressure placental bed causes an increase in blood flow resistance of the systemic vasculature. These are the normal physiological changes observed in the normal neonate after birth. [1]
- Deviations from these can result in pathological conditions requiring immediate interventions; infants, especially those born prematurely will require medical assistance to make this phenomenal transition. [4]
- In peripheral cyanosis, there is normal SaO2 with an increase in oxygen uptake by tissues resulting in a large arteriovenous difference in the venous aspect of the capillaries. Vasoconstriction could also be a cause. This type of cyanosis is seen majorly at the extremities.
Causes
- A systematic way of classifying the common causes of cyanosis in newborns is by using the ABC which stands for Airway, Breathing, and Circulation.
| Causes of Cyanois in newborns | |||||||||||||||||||||||||||||||||||||||||||||||
| Airway | Breathing | Circulation | |||||||||||||||||||||||||||||||||||||||||||||
| • Cystic hygroma • Hemangioma • Choanal atresia • Micrognathia • Laryngomalacia • Tracheal stenosis • Vascular rings • Vocal cord paralysis • Pierre-Robin sequence | • Phrenic nerve palsy • Congenital diaphragmatic hernia • Hypoventilation • Pulmonary hypoplasia • Congenital cystic adenomatoid malformation • Pneumonia | • Congenital heart diseases Tetralogy of Falot Tricuspid atresia Pulmonary atresia Pulmonary stenosis Ebstein's anomaly Transposition of great arteries Hypoplastic left heart syndrome Atrioventricular canal defect Total anomalous pulmonary venous return • Anemia • Methemoglobinemia • Polycythemia • Persistent pulmonary hypertension | |||||||||||||||||||||||||||||||||||||||||||||
Epidemiology and Demographics
- The prevalence of [disease name] is approximately [number or range] per 100,000 individuals worldwide.
- In [year], the incidence of [disease name] was estimated to be [number or range] cases per 100,000 individuals in [location].
Age
- Patients of all age groups may develop cyanosis depending on the etiology.
- It is however commonly observed among newborns due to the peculiarities of birth and the changes that occur during the transition from fetal to neonatal life.
Gender
- No documented eveidence of gender predilection.
Race
- There is no racial predilection for [disease name].
- [Disease name] usually affects individuals of the [race 1] race.
- [Race 2] individuals are less likely to develop [disease name].
Risk Factors
- Common risk factors in the development of cyanosis in newborns are evident in the pregnancy and labor period. [5]
- Pregnancy-related risk factors are:
- Advanced age of the mother
- Pregnancy-induced hypertension
- Gestational diabetes
- Intake of Lithium
- Oligohydramnios
- Labor and birth-related risk factors are:
- Cesarean section
- Preterm/prematurity
- Use of anesthetic drugs and/or sedatives
- Sepsis from Prolonged Rupture of Membrane (PROM)
- Meconium aspiration
Natural History, Complications and Prognosis
- The majority of patients with [disease name] remain asymptomatic for [duration/years].
- Early clinical features include [manifestation 1], [manifestation 2], and [manifestation 3].
- If left untreated, [#%] of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
- Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
- Prognosis is generally [excellent/good/poor], and the [1/5/10year mortality/survival rate] of patients with [disease name] is approximately [#%].
Diagnosis
Symptoms
- Symptoms of cyanosis in the newborn may include the following:
- [symptom 1]
- [symptom 2]
- [symptom 3]
- [symptom 4]
- [symptom 5]
- [symptom 6]
Physical Examination
- Patients with [disease name] usually appear [general appearance].
- Physical examination may be remarkable for:
- [finding 1]
- [finding 2]
- [finding 3]
- [finding 4]
- [finding 5]
- [finding 6]
Laboratory Findings
- There are no specific laboratory findings associated with [disease name].
- A [positive/negative] [test name] is diagnostic of [disease name].
- An [elevated/reduced] concentration of [serum/blood/urinary/CSF/other] [lab test] is diagnostic of [disease name].
- Other laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
Electrocardiogram
There are no ECG findings associated with [disease name].
OR
An ECG may be helpful in the diagnosis of [disease name]. Findings on an ECG suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
X-ray
There are no x-ray findings associated with [disease name].
OR
An x-ray may be helpful in the diagnosis of [disease name]. Findings on an x-ray suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no x-ray findings associated with [disease name]. However, an x-ray may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
Echocardiography or Ultrasound
There are no echocardiography/ultrasound findings associated with [disease name].
OR
Echocardiography/ultrasound may be helpful in the diagnosis of [disease name]. Findings on an echocardiography/ultrasound suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no echocardiography/ultrasound findings associated with [disease name]. However, an echocardiography/ultrasound may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
CT scan
There are no CT scan findings associated with [disease name].
OR
[Location] CT scan may be helpful in the diagnosis of [disease name]. Findings on CT scan suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no CT scan findings associated with [disease name]. However, a CT scan may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
MRI
There are no MRI findings associated with [disease name].
OR
[Location] MRI may be helpful in the diagnosis of [disease name]. Findings on MRI suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no MRI findings associated with [disease name]. However, an MRI may be helpful in the diagnosis of complications of [disease name], which include [complications 1], [complication 2], and [complication 3].
Other Imaging Findings
There are no other imaging findings associated with [disease name].
OR
[Imaging modality] may be helpful in the diagnosis of [disease name]. Findings on an [imaging modality] suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
Other Diagnostic Studies
- [Disease name] may also be diagnosed using [diagnostic study name].
- Findings on [diagnostic study name] include [finding 1], [finding 2], and [finding 3].
Treatment
Medical Therapy
- There is no treatment for [disease name]; the mainstay of therapy is supportive care.
- The mainstay of therapy for [disease name] is [medical therapy 1] and [medical therapy 2].
- [Medical therapy 1] acts by [mechanism of action 1].
- Response to [medical therapy 1] can be monitored with [test/physical finding/imaging] every [frequency/duration].
Surgery
- Surgery is the mainstay of therapy for [disease name].
- [Surgical procedure] in conjunction with [chemotherapy/radiation] is the most common approach to the treatment of [disease name].
- [Surgical procedure] can only be performed for patients with [disease stage] [disease name].
Prevention
- There are no primary preventive measures available for [disease name].
- Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
- Once diagnosed and successfully treated, patients with [disease name] are followed-up every [duration]. Follow-up testing includes [test 1], [test 2], and [test 3].
References
- ↑ 1.0 1.1 1.2 1.3 Steinhorn RH (2008). "Evaluation and management of the cyanotic neonate". Clin Pediatr Emerg Med. 9 (3): 169–175. doi:10.1016/j.cpem.2008.06.006. PMC 2598396. PMID 19727322.
- ↑ Izraelit A, Ten V, Krishnamurthy G, Ratner V (2011). "Neonatal cyanosis: diagnostic and management challenges". ISRN Pediatr. 2011: 175931. doi:10.5402/2011/175931. PMC 3317242. PMID 22482063.
- ↑ 3.0 3.1 Lees MH, King DH (1987). "Cyanosis in the newborn". Pediatr Rev. 9 (2): 36–42. doi:10.1542/pir.9-2-36. PMID 3332361.
- ↑ Hooper SB, Polglase GR, Roehr CC (2015). "Cardiopulmonary changes with aeration of the newborn lung". Paediatr Respir Rev. 16 (3): 147–50. doi:10.1016/j.prrv.2015.03.003. PMC 4526381. PMID 25870083.
- ↑ https://learn.pediatrics.ubc.ca/body-systems/neonate/approach-to-neonatal-cyanosis/