Asphyxia of the newborn. Birth trauma

1. Asphyxia of the newborn. Birth trauma Prof. H.A. Pavlyshyn

2. Definition • WHO: Asphyxia is incapacity of newborn to begin or to support spontaneous respiration after delivery due to breaching of oxygenation during labor and delivery Asphyxia is absense or ineffective respiration of newborn of 1 minute old with Apgar score less than 4

3. Definition • Ukraine:Asphyxia of newborn as a nosological form is conditioned by causes when severe maternal-placental and (or) umbilical blood flow is disturbed and leads to development of metabolic acidosis

4. Asphyxia: means “a stopping of the pulse”, but more useful is a definition of impaired or interrupted gas exchange. These situations can take place: a. Intrauterine:the gas exchange depends on the function of placenta, and the blood-flow in the umbilical vessels. b.Postnatal:after delivery the gas exchange takes place in the pulmonary vesicles or alveoli and depends on the function of the heart, lungs and brain. Asphyxia

5. Causes of Asphyxia Fetal hypoxia: • Mother: hypoventilation during anesthesia, cyanotic heart disease, respiratory failure or carbon monoxide poisoning. • Low maternal blood pressure as a result of the hypotension that may cause compression of the vena cava & aorta by the gravid uterus • Premature separation of the placenta; placenta previa • Impedance to the circulation of blood through the umbilical cord as a result of compression or knotting of the cord • Uterine vessel vasoconstriction by cocaine, smoking • Placental insufficiency from numerous causes, including gestosis, eclampcia, toxemia, postmaturity • Extremes in maternal age (< 20 years or >35 years) • Preterm or postterm gestation.

6. Causes of Asphyxia Intrapartus asphyxia: • More frequently inadequate obstetric aid • Using forceps, vacuumextraction, cresteller, caesarean section (immediate) • Trauma: narrow pelvis, malpresentation • Extremely rapid or prolonged labor • Multiple gestation • Drugs depression of CNS: anesthesia, sedatives & analgesics • Meconium-stained amniotic fluid

7. Causes of Asphyxia Postnatal hypoxia: • Anemia due to severe hemorrhage or hemolytic disease • Shock from adrenal hemorrhage, intraventricular hemorrhage, overwhelming infection, massive blood loss • Failure to breathedue to a cerebral defect, narcosis or injury • Failure of oxygenation resultingfrom of cyanotic congenital heart disease or deficient pulmonary function

8. Predisposing risk factors for asphyxia are: • Multiple gestation; • Placental abruption; • Placenta previa; • Preeclampsia; • Meconium-stained amniotic fluid; • Fetal bradycardia; • Prolonged rupture of fetal membranes; • Extremes in maternal age(senior 35 y, junior 20 y); • Maternal diabetes; • Maternal use of illicit drugs;

9. Apgar Score of the Newborn

10. Postnatal symptoms of ASPHYXIA MILD ASPHYXIA • ° The infant who experiences mild asphyxia initially will be depressed. This is followed by a period of hyperalertness, which resolves within 1 or 2 days. ° Clinical symptoms: • hyperalertness (jitteriness), • increased irritability and tendon reflexes, • exaggerated Moro response; • ° There are no local signs • ° The prognosis is excellent for normal (good) outcome.

11. CRITERIA OF MODERATE ASPHYXIA ° The infant who experiences moderate asphyxia will be very depressed. This is followed by a prolonged period of hyperalertness and hyperreflexia. ° Clinical symptoms: • lethargy, hypotonia • suppressed reflexes with or without seizures • Generalised seizures often occur 12 to 24 hours after episode of asphyxia, but are controlled easily, resolving in a few days regarding of therapy. • ° The prognosis is variable (20-40% with abnormal outcome).

12. CRITERIA OF SEVERE ASPHYXIA • ° Severe metabolic or mix acidosis pH ≤ 7.00 in arterial blood of umbilical vessels; • ° Assessment by Apgar is 0-3 during more than 5 minutes; • ° Neurological symptomssuch as general hypotonia, lethargy, coma, seizures, brainstem, autonomous dysfunction; • ° Evidence of multiorgan system dysfunction in the immediate neonatal period - damage of vital organs (lungs, heart and others) in fetus or newbon;

13. CRITERIA OF SEVERE ASPHYXIA • ° Severe asphyxia is associated with coma, intractable seizures activity, cerebral oedema, intracranial haemorrhage. • ° The infant often became progressively more depressed over the first 1 to 3 days, as a cerebral oedema develops, and death may occur during this period. • Survival is usually associated with poor long-term outcome (100% with abnormal outcome);

14. Acute complications associated with Asphyxia • hypoxic-ischemic encephalopathy (HIE) • hypotension • seizures • persistent pulmonary hypertension • hypoxic cardiomyopathy • necrotizing enterocolitis • acute tubular necrosis • adrenal hemorrhage and necrosis • Hypoglycemia, polycytemia • disseminated intravascular coagulation

15. Hypoxic-ischemic cerebral injury – HIE (encephalopathy) • Is caused by a combination of hypoxemia, ischemia, that results in a decreased supply of oxygen to cerebral tissue • During perinatal asphyxia, birth trauma, hypercapnia and acidosis may contribute further to the cerebral insult.

16. Sarnat criteria • Level of consciousness • Neuromuscular control • Muscle tone • Posture • Stretch reflexes • Segmental myoclonus • Complex reflexes: Suck, Moro, oculovestibular tonic neck • Autonomic function

17. Sarnat criteria • Pupils • Respirations • Heart rate • Bronchial & salivary secretions • Gastrointestinal motility • Seizures • EEG • Duration of symptoms

19. DIAGNOSIS • Clinical symptoms and metabolic derangement – blood sample from the umbilical artery - low pH (< 7, 00) - indicates the intrapartum asphyxia. • Renal and/or cardiac failure • Assessment of the brain: EEG Serial recordings are almost necessary. Low voltage. Burst-suppression patterns or electrical inactivity are associated with bad prognosis. Rapid resolutionof EEG abnormalities and/or normal interictal EEG are associated with a good prognosis.

20. Ultrasoundand Doppler technique • Ultrasound: to measure the growth of the fetus. The growth retarded fetus is in a great risk of developing asphyxia. Ultrasound can be useful in premature newborns. • Doppler techniques: to measure the blood flow in the umbilical vessels or aorta. A low flow or decreasing flow indicates a fetus in risk of asphyxia. • Computed tomography: CT is of major value both acutely during theneonatal period and later in childhood. The optimal timing of CT scanning isbetween 2 and 4 days.

21. ABC resuscitation • A- Airways (maintenance of passableness of airway) • B- breathing (stimulation of breathing) • C- circulation (support of circulation) • D-drug

22. ABC resuscitation • Step A- immediately after delivery the infant’s head should be placed in a neutral or slightly extended position • Roller towel under the shoulders

23. And airway established by clearing the mouth, then the nose by rubber bag

24. If it is inadequate we must use step B. At first the tactile stimulation should be given to newborn, for example - gentle flicking of the feet or heel

25. ABC resuscitation • or rubbing of the back

26. If meconium is present in amniotic fluid, after sucking of mouth and nose we must suck a pharynx by tube after laryngoscope

27. If these measures are inadequate, mechanical ventilation should be initiated, using mask and bag ventilation

28. If ventilation is adequate supplemental oxygen may be given to improve heart rate or skin colour

29. If mechanical ventilation does not improve the respiration, heart rate or colour skin, the following step is “C”-circulation. At first the assessment of heart rate is necessary

30. If heart rate is less than 60 beats/minute, or between 60 and 80 beats and is not improving, cardiac compression must be performed

31. ABC resuscitation • Big fingers must lie on the sternum, other fingers should lie under the back of newborn

32. ABC resuscitation • If heart rate is less then 80 beats per minute the cardiac compression should be continued. • If heart rate is 80 beats per minute or more the cardiac compression should be stopped .

33. Birth trauma • The term “Birth trauma” is used to denote mechanical and anoxic trauma incurred by the infant during labor and delivery. • The process of birth is associated with compressions, contractions, and tractions.

34. Birth trauma • When fetal size, presentation or neurological immaturity complicate this event, such intrapartum forces may lead to • tissue damage, • edema, • hemorrhage • or fracture in the neonate.

35. The risk of birth injury • Small maternal stature • Maternal pelvic anomalies • Extremely rapid • Prolonged labor • Using forceps, vacuum extraction • Versions and extraction • Deep transverse arrest of descent of presenting part of fetus • Oligohydramnions • Abnormal presentation (i.e. breech)

36. The risk of birth injury • Very low birth weight infant or extreme premature • Postmature infant(> 42 week of gestation) • Cesarean section • Fetal macrosomia • Large fetal head • Fetal anomalies (see teratoma)

37. Classification of birth injuries • I. Soft-tissue injuries • - caput succedaneum • - subcutaneous and retinal hemorrhage, petechia • - ecchymoses and subcutaneous fat necrosis

38. Classification of birth injuries • II. Cranial injuries • cephalohematoma • fractures of the skull

39. Classification of birth injuries • III. Intracranial hemorrhage • subdural hemorrhage • subarachnoid hemorrhage • intra- and periventricular hemorrhage • parenchyma hemorrhage

40. Classification of birth injuries • IV. Spine and spinal cord • fractures of vertebra • Erb-Duchenne paralysis • Klumpke paralyses • Phrenic nerve paralyses • Facial nerves palsy

41. Classification of birth injuries • V. Peripheral nerve injuries • VI. Viscera (rupture of liver, spleen and adrenal hemorrhage) • VII. Fractures of bones.

42. Birth trauma • Petechiae and ecchymosis are common manifestation of birth trauma in the newborn. Petechiae of the skin of the head and neck are common. These lesions resolve spontaneously within 1 week. • They are caused by a sudden increase in intrathoracic pressure during labor when the fetus passes through the birth canal. • They are temporary and are the result of normal course of delivery. • If the etiology is uncertain, studies to rule out coagulation disorders or infections etiology are indicated.

43. Birth trauma • Caput succedaneum is a subcutaneous extraperiosteal fluid collection in the presenting part of fetus • is caused by infiltration of subcutaneous soft tissue in the presenting part resulting from pressure in birth canal • with poorly defined margins • it may extend across the midline over suture lines • This swelling is resolved rather quickly within several days post partum.

44. Cephalohematoma • is a subperiosteal collection of blood resulting from rupture of the blood vessels between the skull and pereostium • its does not extend over suture lines between adjacent bones. • Its occurrence is commonly on one side of the head • The extent of hemorrhage may be severe enough to present as anemia and hypotension with secondary hyperbilirubinemia.

45. Birth trauma

46. It may be a focus of infection leading to meningitis, particularly when there is a concomitant skull fracture. Skull X-rays should be obtained if there are CNS symptoms, if the hematoma is very large or if the delivery was very difficult. • Resolution occurs over 1 to 2 month, occasionally with residual calcification as a thrombus.

47. Birth trauma • INTRACRANIAL HEMORRHAGE • Occurs in 20% to more than 40% of infants with birth weight under 1500 gm, • is less common among more mature infants. • Intracranial hemorrhage may occur in the subdural, subarachnoid, intraventricular or intracerebral regions. • Subdural and subarachnoid hemorrhage follow head trauma (e.g. in breech, difficult and prolonged labor and after forceps delivery). • Other forms of intracranial bleeding are associated with immaturity and hypoxia.

48. Predisposing factors of IVH • premature • respiratory distress syndrome, apnea • pneumothorax • congestive heart failure • presence of patent ductus arteriosus • hypoxic ischemic or hypotensive injuries • increased venous pressure • hypervolemia, hypertensia

49. The structural and functional factors of IVH in low-birth-weight infants • poor structural support of germinal matrix vessels • relatively large blood flow to deep cerebral structure • hypoxic-ischemic injury to germinal matrix or its vessels

50. Clinical manifestation of IVH • Absent Moro reflex • Weakness, seizures, muscular twitching • Poor muscle tone • Hypotonia • Lethargy • excessive somnolence • Pallor or cyanosis • Respiratory distress • Jaundice