ASPHYXIA AND Respiratory fetal distress

ASPHYXIA AND Respiratory fetal distress

1. 1 BIRTH ASPHYXIA

2. INTRODUCTION 2 New born infants normally start to breathe without assistance and usually cry after delivery. By one minute after birth, most infants are breathing well. If an infant fails to sustain respirations after birth, the infant is diagnosed with asphyxia neonatorum .

3. INTRODUCTION 3 Asphyxia is as a result of intra uterine hypoxia , a deficiency of O2 in tissues & hypercapnea ( excessive concentration CO2) in the blood prior to or at delivery. Asphyxia Neonatorum requires emergency treatment because it can lead to complications such as brain damage and death may follow if not corrected immediately.

4. INTRODUCTION 4 Therefore the midwives attending to a pregnant woman should be very competent Be able to anticipate and recognize the problem of asphyxia Be skilled or proficient in immediate resuscitation technique to save the lives of these babies. Initiate immediate intervention Be proficient in initial magnt of infant at birth

5. GENERAL OBJECTIVES 5 At the end of this lecture students should be able to acquire the knowledge and skills in the management of the baby with asphyxia neonatorum

6. SPECIFIC OBJECTIVES 6 At the end of this lecture students should be able to; Define Asphyxia Neonatorum State the causes/predisposing factors Describe in detail the pathophysiology of Asphyxia Neonatarum Explain the types of asphyxia neonatorum Discuss the Management of a baby with Asphyxia Neonatorum or Birth Asphyxia State the complications of Asphyxia Neonatarum

7. Definition of terms 7 Asphyxia neonatorum is a condition in which a viable newborn infant fails to initiate and sustain respirations after delivery (Sellers P.M, 2010). Asphyxia neonatorum is failure to establish and sustain respiration at birth (Novak and Broom 1999).

8. CAUSES/ PREDISPOSING FACTORS 8 Factors that cause intra-uterine hypoxia prior to or at delivery. These may be 1. Maternal causes 2. Placental and cord causes 3. Foetal causes  

9. CAUSES/ PREDISPOSING FACTORS 9 1. Maternal causes (may occur during anc ) A. Lack of oxygen in the maternal circulation (hypoxia) due to: Severe anemia Severe cardiac disease Respiratory disease such as tuberculosis, pneumonia, asthma…

10. CAUSES/ PREDISPOSING FACTORS 10 Maternal causes ………………….. B. Reduction in uterine blood flow (vasoconstriction) due to: Severe hypertension Ante-partum hemorrhage Aorto-caval compression Supine hypotension syndrome

11. CAUSES/ PREDISPOSING FACTORS 11 2. Placental causes Placental infarcts Placental separation (placental prae -via, placental abruption or trauma). 3. Fetal causes Intra-uterine growth retardation Prematurity Birth injury

12. CAUSES/ PREDISPOSING FACTORS 12 4. Umbilical causes Knots in the cord Cord compression Prolapsed of the cord Short cord

13. CAUSES/ PREDISPOSING FACTORS 13 During labor Depression of baby's respiratory centre by drugs or anaesthesia given to the mother few hours (4 hours) before delivery such as pethidine, diazepam. Misuse of oxytocin drugs in labour (when you have good contractions) may cause severe uterine contraction (h ypertonic ) with poor resting tone in between contractions leading to fetal distress and asphyxia follows. Prolonged labor

14. CAUSES/ PREDISPOSING FACTORS 14 In the neonatal period ( At birth) Blockage of air ways due to aspiration of meconium, blood, mucus and/or liquor Congenital abnormalities such as nose atresia Severe disease such as anemia, septicemia

15. PATHOPHYSIOLOGY 15 Oxygenation of the fetus is dependent on oxygenation of the mother , adequate perfusion of the placental site , placental function, fetoplacental circulation and adequate fetal hemoglobin . Absence or impairment of any of these factors will result in a reduction of oxygen supply to the fetus leading to intra-uterine hypoxia.

16. PATHOPHYSIOLOGY 16 Initially, the fetus responds to hypoxia by accelerating its heart rate in an effort to maintain supplies of oxygen to the brain. At birth the infant becomes cyanosed and apnoeic and this is called asphyxia livida (dark blueish grey in colour)

17. PATHOPHYSIOLOGY 17 If hypoxia persists, glucose depletion will stimulate anaerobic glycolysis resulting in a metabolic acidosis. Cerebral vessels dilatation and brain swelling may occur. Peripheral circulation will be reduced to meet the demands of heart and brain; and cardiac glycogen reserves are also depleted.

18. PATHOPHYSIOLOGY 18 With increasing hypoxia, circulatory collapse and bradycardia increases and the baby now passes into the phase of Asphyxia pallid (pale) With continued bradycardia, the anal sphincter relaxes and the fetus may pass meconium into the liquor. Gasping breathing movements triggered by hypoxia result in the aspiration of meconium stained liquor into the lungs which presents an additional problem after delivery.

19. TYPES OF ASPHYXIA 19 There are two main types of asphyxia namely : mild and severe asphyxia. Mild Asphyxia It is often caused by obstruction to the airway. It is of short duration and responds to prompt and adequate treatment especially suctioning.

20. SIGNS & SYMPTOMS MILD ASPHYXIA 20 Short delay in onset of respirations (30 seconds). The Apgar score is 5 – 7 with good muscle tone. Response to stimuli is present. The baby is deeply cyanosed. Cord pulsation is strong and cord feels firm.

21. SIGNS & SYMPTOMS SEVERE ASPHYXIA 21 This occurs due to intra uterine hypoxia and is of long duration. Apgar score is less than 5. Baby makes no attempt to breath. Heart rate is slow and feeble (less than 40beats/minute). Muscle tone is poor and baby is limp and unresponsive to stimuli. Baby looks pale and grey (Cyanosis) The baby is in shock.

22. MANAGEMENT 22 Aims Establish and maintain a clear air way Maintain a normal heart rate Maintain normal respiratory rate and pattern Ensure effective circulation. Correct acidosis. Prevent hypothermia and hypoglycemia.

23. MANAGEMENT 23 Management and care; depend on the severity of the condition. depends on neonatal resuscitation which comprises of a series of actions that are taken in order to revive a newborn baby. First and foremost, preparations are done before baby is born

24. MANAGEMENT 24 As part of ward routine the resuscitaire should be prepared by the midwife ward daily. The equipment should be available and in good working condition. Preferably each delivery room should have a resuscitaire. Do a quick assessment using the apgarscore

25. SIGN SCORE 1 2 Heart rate Absent Less than 100/min Over 100/min Respiratory effort Absent Weak/ irre -gular Strong/re-gular Muscle tone Atony Some flexion Active movement Reflex irritability No response Grimace Cough or sneeze Color Universal cyanosis or pallor Pink body, acrocyano-sis Completely pink 25

26. MANAGEMENT… 26 Interpretation of the Apgar score, in asphyxia neonatorum 8- 10: no respiratory depression and the infant is in good condition 5- 7: the infant has mild asphyxia 3-4: the infant has moderate asphyxia 0-2: the infant has severe asphyxia

27. MANAGEMENT 27 The Apgar score at one minute shows the immediate situation and is an index of asphyxia and the need for intervention and resuscitation. The score obtained at five minutes after birth gives a good indication of the infants response to resuscitative measures and ability to withstand hypoxemia, and correlates best with the long term prognosis for mental development and or/ neonatal death ( Sellers P.M, 2010).

28. MANAGEMENT 28 Nursing considerations Make sure the working environment is prepared whenever one reports for work in anticipation of emergencies Equipment should be tested and in working condition. All the instruments required for resuscitation should be available.

29. MANAGEMENT 29 Preparation for resuscitation Preparation includes equipment, medicines and staff. Equipment includes: Pre-warmed resuscitaire or flat surface for resuscitation. Penguin sucker. Working suction machine. Suction tubes size 6 or 8. Endotracheal tube size 2mm, 2.5mm, 3mm, and 3.5. Pediatric ambu bag with face mask, cannulars , sterile gloves…

30. MANAGEMENT 30 Equipment …. Pediatric laryngoscope with correct blade. Oxygen cylinder or concentrator. Intravenous fluids like 5% dextrose, Artificial ventilation machine. Overhead radiant warmer. Stop watch. Stethoscope Sterile disposable syringes and needles.

31. MANAGEMENT 31 Drugs to combat acidosis and stimulate respiratory centre such as Dextrose solution 10% or 5%, Sodium bicarbonate 4%, Normal saline Drugs such as naloxane hydrochloride ( Narcan ), Adrenaline1:10.000 should be available.

32. IMMEDIATE CARE OF THE NEWBORN 32 During 2 nd stage of labour, after delivery of the head, do the following interventions; Wipe off the excess secretions from nostrils & mouth - to prevent the baby from aspirating the secretions and to help initiate respirations. Feel for the cord around the neck. If loose, slip it over the shoulders but if tight clamp with 2 forceps and cut it to prevent strangulation.

33. Immediate Care ………… 33 When the whole body is delivered over the mother’s abdomen, the midwife quickly wipes off the secretions to prevent hypothermia by evaporation. Note the Apgar score at one minute after birth to check if the baby needs resuscitation immediately. Upon having a quick assessment of the baby and the condition is unsatisfactory, cut the cord long for resuscitation measures such as administration of drugs.

34. Immediate Care …… 34 Note the time of delivery as it helps to assess the duration of resuscitation . Show the baby to the mother to identify the sex and quickly explain the condition to the mother.

35. RESUSCITATION OF THE ASPHYXIETED BABY 35 Is the major management of the asphyxiated baby. Aims of resuscitation To establish respiration and maintain ventilation To establish cerebral circulation and so prevent cerebral and other organ cell damage To avoid acidosis, hypothermia, hypoglycemia and to maintain blood pressure

36. RESUSCITATION…. 36 Transfer baby to the resuscitaire with the radiator heater on for warmth. Put baby in a supine position with the head slightly extended to maintain a clear airway (neutral position) use the neonatal resuscitation algorithm to resuscitate the baby

37. RESUSCITATION…. 37 Ventilate with mask closely fitting mask applied over the baby’s nose and mouth taking care not to encroach on baby’s eyes. The baby’s jaw must be held forward and supported to maintain the patent airway. If the baby fails to respond to intermittent positive pressure ventilation (IPPV) by the mask and the bag, or if bradycardia is present, endotracheal intubation by the doctor should be done without delay.

38. RESUSCITATION…. 38 Complications of intubation Pneumothorax- can occur if the Endotracheal tube is inserted too far into the right bronchus Tracheal perforation Esophageal perforation Laryngeal oedema may occur after extubation causing respiratory distress .

39. RESUSCITATION…. 39 If bradycardia persists or the heart rate is less than 100 beats per minute, external cardiac massage may be applied. This is achieved by placing the tips of the index fingers of one hand over the middle sternum or by encircling the baby’s chest with the fingers on the spine and thumbs on the lower mid sternum by depressing the chest at the rate of 100-120 times per minute.

40. Position for cardiac Compressions in the neonate 40

41. Alternative Position 41

42. RESUSCITATION…. 42 If still the respirations cannot be initiated, the following drugs can be given: Naloxone hydrochloride 100mg per kg body weight via the umbilicus or IM to reverse the effects of maternal narcotic effects. Sodium bicarbonate 5ml IV is given to correct metabolic acidosis. Sodium bicarbonate is given slowly to avoid rapid elevation of serum osmolarity with the risk of intracranial haemorrhage .

43. RESUSCITATION…. 43 Dextrose 5ml of 5% or 10% may be given IV to correct or prevent hypoglycemia. Vitamin K: up to 2ml may be given IM to reduce the risk of haemorrhage Dexamethasone: 1-2mg may be given IV or IM to minimize the risk cerebral oedema if severe asphyxia is present .

44. SUBSEQUENT CARE 44 Subsequent care of the newborn will depend upon the response to resuscitation. The baby that responds promptly is united with the mother and subsequent care of the newborn is given while a baby whose condition requires further management is rushed to the neonatal intensive care nursery for further management.

45. COMPLICATIONS OF NEONATAL ASPHYXIA 45 May be due to the condition itself or procedures. Hypoxemia- leading to brain damage and deafness. Hypercapnea - leads to vasodilatation of the cerebral vessels and congestive oedema resulting to rupturing of cerebral vessels. Acidosis Respiratory acidosis Metabolic acidosis

46. 46 COMPLICATIONS ………….. Aspiration pneumonia Pneumothorax Tracheal perforation . Mental retardation/ Brain damage / -due to the death of brain cells following hypoxia.

47. Other complications include : 47 Hypoglycemia Acute renal failure. Atelectasis. Ischaemic hypoxia encephalopathy. Respiratory Distress Syndrome

48. PREVENTION OF ASPHYXIA NEONATORUM 48 Good antenatal care. Taking note of high risk pregnancies and these should be delivered in hospital. Good management of labour to avoid prolonged labour. Avoid giving drugs such as pethidine to the mother especially 4 hours before delivery or when cervix is 6cm cm dilated.

49. 49 THE END of part 1 BREAK????

50. 50 RESPIRATORY DISTRESS SYNDROME (RDS)

51. INTRODUCTION 51 Respiratory Distress syndrome (RDS) is used interchangeably with the diagnosis of Hyaline Membrane Disease (HMD) The diagnosis for HMD is derived at from the presence of hyaline membranes in the airways resulting from the damaged epithelium RDS refers to the clinical disease process which occurs as a result of insufficient production of surfactant RDS is seen mostly in premature babies but can be mimicked by other conditions such as maternal DM and Asphyxia neonatarum .

52. GENERAL OBJECTIVE 52 At the end of this lecture students should be able to acquire the knowledge and skills in the management of the baby with Respiratory Distress syndrome or HMD

53. SPECIFIC OBJECTIVES 53 At the end of this lecture students should be able to; Define Respiratory Distress syndrome or HMD State the causes/predisposing factors for Respiratory Distress syndrome or HMD Describe in detail the pathophysiology of Respiratory Distress syndrome or HMD List the signs and symptoms of RDS Discuss the Management of a baby with Respiratory Distress syndrome or HMD State the complications of Respiratory Distress syndrome or HMD

54. DEFINITION 54 RDS or Hyaline membrane disease is a condition characterized by difficulty in breathing few hours or soon after birth which is mostly confined to preterm babies because of lung immaturity caused by deficiency of lung surfactant.

55. INCIDENCE 55 10-15% seen in babies weighing about 2.5kg or less due to short gestation (prematurity). Unusual in low birth weight babies born after 37 completed weeks of gestation. Incidence higher in babies of Diabetic mothers, weighing more than 2.5kg and born before 36 th week of gestation.

56. Incidence cont; 56 Incident is lower in babies of short gestation age delivered when the pregnancy was complicated by PROM. This is because there tends to be accelerated development of pulmonary surfactant.

57. Predisposing factors 57 Preterm babies weighing 2.5kg or less Low birth weight born after 37 weeks of gestation Babies of diabetic mothers (LGA) Maternal and foetal factors resulting in preterm labour and birth ( Incidence lower in P/E and PROM) Asphyxia due to reduced oxygen tension reduces synthesis of surfactant.

58. Predisposing factors… 58 Conditions that inhibit synthesis of surfactant= hypoxia, hypoglycaemia, hypothermia and acidosis Caesarean delivered babies non discharge of fluids from the lungs. Multiple pregnancy Pre-eclampsia immaturity

59. OTHER CAUSES OF RESPIRATORY DISTRESS IN THE NEWBORN 59 Transient Tachypnoea of the newborn. - found in term babies with mature lungs but delays in clearing of lung fluids. - Commonly found in babies born by c/s. - attributed to gradual chest compression.

60. other causes….. 60 2.Meconeum Aspiration Syndrome- Usually seen n small for dates babies, post mature with fetal distress. Liquor inhalation causes the syndrome characterized by respiratory distress. 3.Transient Tachypnoea of the New born (TTN). Usually found in term babies with mature lungs. Common in babies delivered by caesarean section.

61. other causes…. 61 Pneumothorax Congenital pneumonia Pulmonary haemorrhage Drugs given to the mother

62. PATHOLOGY 62 In this condition there is insufficient surfactant , a substance present in the alveolar walls. Surfactant serves to reduce surface tension and adhesiveness within the lung alveoli so that whatever their size, the same pressure is required to inflate them., thus ensuring uniform inflation of the alveoli.

63. Pathology.. 63 Surfactant is a complex phospholipid secreted by type II alveolar cells from about 22 weeks of gestation but only seen in lung fluid after 30 weeks. Measurement of surfactant is expressed as a ratio between Lecithin and Sphingomyelin in tracheal fluid and the ratio is 2:1, this ratio denotes that the fetus or baby is mature.

64. Pathology…. 64 When surfactant is little or deficient, surface tension in smaller alveoli is very great, causing them to collapse. Larger alveoli continue to expand resulting in uneven expansion with progressive alveolar collapse

65. Pathology… 65 For normal lung function, it is essential to have enough surfactant so as to reduce surface tension and keep the alveoli expanded following expiration.

66. SIGNS & SYMPTOMS 66 Condition of the baby is good at birth with an Apgar Score of 9/10. Within a few hours (4 plus) the baby develop progressive difficult in breathing . Resp. rate rises ( tachypnoea ) to >60/minute

67. Clinical course…. 67 flaring of nares Intercostal recession on inspiration Granting on expiration substernum / suprasternal The intercostal recessions are due to inability to exert enough inspiration pressure to expand the alveoli. Seesaw respiration

68. Clinical course…. 68 Expiratory grunting is from an attempt to expire against a partially closed larynx, thus delaying alveolar collapse. --Alveolar ventilation is progressively reduced with resultant hypoxemia clinically presenting as cyanosis. -- Cyanosis may be reduced by 40% Oxygen at first, then may become unresponsive even to high level of Oxygen.

69. Clinical course… 69 Increased hypoxia leads to retention of more Carbon dioxide producing respiratory and metabolic acidosis which further hinders synthesis of surfactant .

70. INVESTIGATIONS or Diagnosis 70 History ANC Labour G/A= premature - Apgar 9/10 then condition starting to deteriorate.

71. INVESTIGATIONS….. 71 Auscultation of lungs reveals reduced breath sounds. Chest X-ray shows a characteristic fine “ground glass” mottling distributed fairly, evenly through the lung field with a poorly defined cardiac boarder Blood gas analysis- blood gaseous rule out respiratory deficiency

72. PROGNOSIS 72 Baby’s condition deteriorates progressively during the first 24-48hrs after birth, then signs of distress decrease and recovery usually occurs after 72hrs when the baby starts to synthesize surfactant

73. MANAGEMENT 73 The treatment and nursing care of an infant with RDS is largely supportive and includes all the general measures required for a premature infant.

74. Objectives of Care 74 Maintain respiration. Prevent hypoglycemia. Reduce or reverse metabolic acidosis. Prevent hypothermia. Prevent complications such as metabolic acidosis.

75. 1. Maintain a clear airway 75 Maintain patent air way by suctioning gently. Gentle suctioning is done to remove secretions that interfere with gaseous flow in the respiratory tract. With a clear airway, Oxygen is then administered. The goals of oxygen therapy are to provide adequate oxygen to the tissues, prevent lactic acid accumulation resulting from hypoxia.

76. Maintain clear airway… 76 It is required that the oxygen be warmed and humidified. If the infant does not require mechanical ventilation, oxygen is supplied by nasal cannula or via nasal catheter in conjunction with continuous positive airway pressure (CPAP).

77. Maintain clear airway… 77 If oxygen required concentration is above 30%, oxygen can be supplied to a plastic hood placed over the infants head to supply variable concentrations of humidified oxygen. Respiratory assessment, Blood gas analysis and degree of cyanosis are reliably used to control the amount of oxygen to administer.

78. Maintain clear airway… 78 Blood gas analysis (PaO2 and PC02) can be measured by the monitor but if this is not available samples of blood are taken 4 hourly and analyzed. If there is still evident cyanosis, the nurse should then increase incubator oxygen concentration until central cyanosis is relieved.

79. Maintain clear airway… 79 At this stage, if oxygen saturation of the blood cannot be maintained at a satisfactory level and carbon dioxide level (PaC02) rises, the infant will require ventilatory assistance.

80. Indications for mechanical ventilation 80 Rising arterial C02 tension (PaC02) Falling arterial 02 tension (Pa02) Fall in respiratory rate/ apnoea Cyanosis unrelieved by high concentrations of oxygen. Falling blood pressure and tachycardia; progressing to pallor which is an evidence of peripheral circulation failure.

81. Methods of 02 therapy 81 Continuous positive airway pressure (CPAP) – First method used. It provides constant distending pressure to airway in spontaneously breathing infants. This method prevents the alveoli from collapsing by maintaining a continuous positive transpulmonary pressure throughout pulmonary cycle. It requires nasal catheter, nasopharyngeal tubes O2 concentrations are usually high, 80% initially but reduced by 5% until 40%.

82. 82 Intermittent Positive Pressure Ventilation (IPPV) Indications for changing to mechanical ventilation include : Pa02 of less than 40mmHg Apnoea not responding to resuscitation. This method maintains a continuous positive pressure to airways in infants attached to the ventilator. It requires endotracheal intubation.

83. 2. Correction of acidosis 83 Corrective measures are taken to maintain PH above 7.25, a fall in blood PH is due to respiratory acidosis- so give Sodium Bicarbonate 4.2% 1-2mls IV. For Metabolic acidosis give 20% Dextrose 1-2mls/kg body wgt IV. PH is measured after an hour and further adjustments are made.

84. 3. Surfactant replacement 84 Synthetic or exogenous surfactant is administered to preterm neonates with RDS. It is sprayed into the lungs through an endotracheal tube at birth. This improves lung expansion and blood gas values. Suctioning should be delayed for an hour when surfactant is administered.

85. Nursing Care 85 Care of infants with RDS involves all observations and interventions of high risk infants. The nurse should be concerned with the complex problems related to respiratory therapy and the constant threat of hypoxemia and acidosis that complicates the care of these infants.

86. Maintenance of patent airway and breathing. 86 Mucus may collect in the respiratory tract due to the infants pulmonary condition. Suctioning should be done on assessments and not routinely. Assessments include auscultation of the chest, evidence of decreased oxygenation, excess moisture in the ET tube or increased infant irritability.

87. Maintenance of patent airway and breathing 87 Precribed oxygen is administered and adjusted according to the levels of gases in the blood .

88. Position 88 Good positioning is very important to facilitate airway expansion and prevent collection of secretions. This allows oxygen entry into the bronchial tree and alveoli. The baby lies on the side (lateral) with the head supported in alignment by a small or thin folded blanket. OR on the back, positioned to keep the neck slightly extended. With the head slightly extended, the trachea opens to its maximum.

89. Position… 89 However,change positions 2 hourly and use water pillows to guard against skin breakdown

90. 3. Observations 90 Baby to be nursed in an incubator Apex beat 2 hourly Respirations ½ hourly, Observe for signs of respiratory distress- nasal flaring, retractions, tachypnea, apnea, grunting. Temp. checked 2hourly – maintain it at 36.5ºc - 37ºc, regulate incubator temp accordingly Humidity should be between 60-80% Observe state of hydration ( e.g , skin turgor , blood pressure, edema, weight, mucous membranes, fontanel) .

91. Observations….. 91 Observe color and activity of baby Urine output-Increased urination is a good sign. Inspection of the skin is part of the infants assessment.

92. Thermoregulation 92 Baby nursed in an incubator . Monitor the temperature of the infant and that of the incubator half hourly to prevent hyperthermia or hypothermia Skin temperature should be 36.4 to 37.2 degrees Celsius

93. 4. Hydration and Nutrition 93 In acute state IVF of 5-10% Dextrose with 0.18% Sodium Chloride (Dextrose saline) is maintained to provide nutrition, the amount given each day is calculated according to age and wgt of baby. As baby’s condition improves give feeds by naso-gastric tubes (EBM if possible). Gradually increase feeds and gradually reduce IVF until baby starts breastfeeding.

94. 5. Medication 94 Antibiotics to combat risk of infections. Vit K to prevent bleeding 0.5mg if <2.5 kg and 1mg if > 2.5 bwt.

95. Hygiene & Skin care 95 Ensure the incubator is cleaned daily The linen should be dry Top and tail done twice daily. Exert extreme care when performing activities involving skin (e.g. removing dressing, electrodes, tape)

96. Psychological care 96 Involve the mother in the care of baby Explain every procedure done on the baby, to her Let her hold the baby during the period of care

97. Complications 97 Intra ventricular haemorrhage due to hypoxia. Pneumothorax due to rupture of alveoli. Intra pulmonary haemorrhage Disseminated intravascular coagulation Infection.

98. THE END THANK YOU! 98