APNEA IN NEWBORN (1) and how to diagnose it.pptx

Apnea in newborn

1. APNEA IN NEWBORN

2. Cessation of breathing for> 20 seconds or for shorter duration in presence of bradycardia or change in skin colour(pallor or cyanosis). Bradycardia - <100 bpm Desaturation - < 80-85%. DEFINITION

3. PERIODIC BREATHING: Cessation of breathing for about 15 sec without vital changes.Common in preterms at 2-6 week of life during quite sleep. Intermittent hypoxia: Short and repetitive episodes of hypoxemia and desaturation without bradycardia or apnea .

4. Inveresly proportional to gestational age. 10-25%: 34 weeks of gestation >60% : < 28 weeks of gestation Apnea of infancy: Apnea in term baby. Persistent apnea : Apnea continuing beyond 37 weeks of PMA. Extreme apnea event: Apnea > 30 sec and/or heart rate <60 for >10 seconds. INCIDENCE

5. PHYSIOLOGY

6. APNEA OF PREMATURITY Immaturity of the brainstem and peripheral chemoreceptors resulting in abnormal ventilator response to hypoxia and hypercarbia . Immature reflex responses Presents after 1-2 days of life and within 7 days. Apnea in 1 st 24 hours and beyond 7 days of life :more likely to have secondary cause. ETIOLOGY

7. Temperature instability: Both hypothermia and hyperthermia Metabolic: Acidosis, hypoglycemia , hypocalcemia , hypo/hypernatremia. Hematological : Anemia,polycythemia Neurological: Intracranial hemorrhage,infections , seizures,perinatal asphyxia,MgSO4 in mother,placental transfer of narcotic drugs. Cardiac: CHD, PDA, hypo/hypertension SECONDARY CAUSES

8. Gastro intestinal: NEC, gastro esophageal reflx,abdominal distension. Infections: Sepsis,pneumonia,meningitis,necrotising enterocolitis .

9. . In fetal life,placenta does the gas exchange with intermittent breathing. In postnatal life,a continuous respiratory muscle activity is required to maintain gas exchange. In AOP ,the ventilation processes are disrupted and thus exchange not possible. PATHOGENESIS

10. CO2 chemosensitivity Response to hypoxia and hyperoxia Sensitivity to neurotransmitters Laryngeal reflexes Ventilation control processes

11. CO2 chemosensitivity

12. Sensitivity to neurotransmitters

13. The reflex apnea has been shown to be associated with contraction of Thyroaretenoid muscle,causing closure of glottis and swallowing Movements,which signify active stimulation of expiratory related Brainstem cen tr es .

14. CENTRAL ( 40% ) : Characterised by cessation of inspiratory efforts due to reduced central drive.No chestwall and abdominal movements. OBSTRUCTIVE(10%) : Here inspiratory effort present but not able to breathe due to obstructed airway due to secretions,too much neck flexion etc. MIXED( 50%) : Most common. Initial reduced central drive followed by obstructed airway. TYPES

15. Respiration: Neonatal cardiorespiratory monitors utilise impedence technology to measure respiration which only measures chestwall movements.Hence effective only to diagnose central apnea . Heart rate: Identifies bradycardia Pulse oximetry : Identifies desaturation. MONITORS FOR APNEA

16. Apnea of prematurity is a diagnosis of exclusion. All other secondary causes to be ruled out on individual basis depending on the history. INVESTIGATIONS

17. Immediate management Tactile stimulation Neck in slight extension Airway suctioning if secretions present O2 support if hypoxia PPV to be initiated if infant does not respond to tactile stimulation. MANAGEMENT

18. PHARMACOTHERAPY Methylxanthines : Mainstay of treatment Not indicated for prevention of apnea of prematurity or for secondary causes. MOA: Competitive antagonism of adenosine receptors .Increases minute ventilation Improves CO2 sensitivity Decreases hypoxic depression of breathing and periodic breathing. Enhances diaphragmatic contractility. SPECIFIC MEASURES

19. CAFFEINE CITRATE THEOPHYLLINE HALF LIFE 25-371 HRS(101 HRS) 13-29 HRS DOSE LD:20mg/kg of caffeine citrate(10mg/kg of caffeine) MD: 5-10 MG/KG/day of caffeine citrate LD: 5-6 mg/kg MD: 1.5-3 MG/KG Q8-12H THERAPEUTIC DRUG LEVEL 8-20microg/ml 5-10microg/ml TOXICITY Broad therapeutic window Narrow therapeutic window

20. 1ml: 20 mg Trade name: R- CAFF LD: 20 mg/kg followed by MD Of 5 mg/kg after 24 hours.

21. INDICATIONS: When apneic episodes are frequent If baby requires PPV for apnea that is unresponsive to tactile stimulation. Methylxanthines are continued till 34 weeks of PMA and stopped if no Episode of apnea has occurred in last 7 days. ADVERSE EFFECTS Tachycardia Jitteriness Irritability Feed Intolerance Vomiting Hyperglycemia

22. What if there is apnea on caffeine? Additional dose of 10mg/kg caffeine citrate can be given. Maintanence dose can be increased by 20%. If administered orally, methylxanthenes are best given with feedings. Because,the daily caffeine dose often disrupts the infant’s sleep pattern at night. Input and output should be monitered because methylxanthines can cause mild diuresis. Stools should be checked for occult blood because these drugs can cause gastric irritation and in some cases lead to NEC.

23. Available as 1 ml solution 1ml=20 mg caffeine citrate PRICE: Rs 265 OTHER BRANDS CAFIRATE APNICAF CAFWELL

24. CPAP CPAP effectively treats mixed and obstructive apnea but not pure central apnea . It stabilises partial pressure of O2 by increasing the functional residual capacity,altering the influence onn stretch receptors on respiratory timing or by splinting the upper airway in open position.

25. NIPPV can be tried if methylxanthine and CPAP therapy fails. NIPPV improves patency of upper airway by creating intermittently elevated pharyngeal pressure. Intermittent inflation of pharynx activate respiratory drive by Heads paradoxical reflex,wherein lung inflation provokes an augmented inspiratory reflex. Nasal Intermittent positive pressure ventilation

26. Normal lung ventilation Ventilator settings MODE: SIMV PRVC/ SIMV PC WITH PS FiO2: 100% then tapered to minimal settings RR : 40 PIP: 10-12 PEEP:5 I:E RATIO: 1:2 PS above PEEP: 8-10 MECHANICAL VENTILATION

27. Remains controversial Transfusion of PRBC if hematocrit is <25% to30% and the infant has episodes of apnea and bradycardia that are frequent or severe while continuing treatment with caffeine. Blood transfusion role in reducing apneic spells

28. Spastic diplegia or quadriplegia Bilateral retrolental fibroplasia resulting in significant visual impairment. Sensorineural deafness Varying degrees of mental retardation. COMPLICATIONS