Prepared by: Ayda Khader Respiratory problems. 2 Out line: Objective Pathophysiology Signs of...

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Objective : list the signs of respiratory distress identify the pertinent anatomical features that contribute to neonatal respiratory distress describe some of the common neonatal respiratory conditions discuss neonatal respiratory and cardiovascular support define the effects of the environment upon the neonate explain the options for maintaining nutrition and hydration propose measures to support the parents with a baby in the neonatal unit. 3

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Prepared by: Ayda Khader Respiratory problems 2 Out line: Objective Pathophysiology Signs of respiratory compromise Common respiratory problem Respiratory care Neonatal ventilation A safe environment Objective Pathophysiology Signs of respiratory compromise common respiratory problem Respiratory care Objective : list the signs of respiratory distress identify the pertinent anatomical features that contribute to neonatal respiratory distress describe some of the common neonatal respiratory conditions discuss neonatal respiratory and cardiovascular support define the effects of the environment upon the neonate explain the options for maintaining nutrition and hydration propose measures to support the parents with a baby in the neonatal unit. 3 Neonates are susceptible to respiratory compromise, for a number of reasons: This may be a result of their stage of lung development and contributing lack of maturation in the other body systems. The gestation of the baby at birth has implications for the susceptibility to disease processes like hyaline membrane disease (HMD), where surfactant production is inhibited. 4 Neonates experience an increased work of breathing owing to the high compliance of the neonatal lung, resulting from the cartilaginous nature of the rib structure. This flexibility allows for some collapse of the airways with each breath, which would not occur with a rigid rib structure. Subsequently, with each breath, the baby needs to generate larger pressures within the lung to prevent respiratory compromise through airway collapse. 5 Neonates also have a different diaphragmatic muscle structure to adults. The neonatal diaphragm is more susceptible to fatigue owing to the composition and the location of the muscle within the neonatal chest. The size of neonatal airways is smaller, which generates higher resistance to air flow and a smaller area through which perfusion can occur. 6 the tendency for pulmonary blood flow to bypass areas of hypoxia, across the alveolar bed, consequently reducing the alveoli perfusion. 7 Signs of respiratory compromise Grunting Grunting is an audible noise heard on expiration. The sound appears when there is partial closure of the glottis as the breath is expired. The baby is attempting to preserve some internal lung pressure and prevent the airways from collapsing completely at the end of the breath. 8 Retractions Chest distortions occur due to an increase in the need to create higher inspiratory pressures in a compliant chest. They appear as intercostal, subcostal or sternal recession across the thorax. 9 Asynchrony Here the breathing has a see-saw pattern as the abdominal movements and the diaphragm work out of unison. This is a result of increased muscle fatigue and the compliant chest wall. 10 Tachypnoea This is a compensatory rise in the respiratory rate initiated from the respiratory centre. It is described as a breathing rate above 60, and aims to remove the hypercarbia and prevent hypoxia Nasal flaring This is an attempt to minimize the effect of the airways resistance by maximizing the diameter of the upper airways. The nares are seen to flare open with each breath. 11 Apnoea Apnoea is an absence of breathing for more than 20s. Apnoea occurs as the conclusion of increasing respirator fatigue in the term baby. The pre-term baby may also experience apnoea of prematurity due to the immature respiratory centre and obstructive apnoea from occluded airways. 12 Common respiratory problems Pneumothorax pneumothoraces are known to occur spontaneously in 1% of the newborn population either during or after birth pneumothorax at birth is caused by the large pressures generated by the baby's first breaths. These may be in the range of up to 4080cm of water. This can lead to alveoli distension and rupture that allows air to leak to a number of sites most notably the potential space between the lung pleura. 13 Babies receiving any assisted ventilation have an increased susceptibility to a pneumothorax. there may be reduced breath sounds on the affected side, displaced heart sounds and a distorted chest/diaphragm movement with respiration and distension of the chest on the affected These signs become harder to detect in the baby with bilateral pneumothoraces. side 14 X-ray examination is the major method for definitive diagnosis of pneumothorax 15 Treatments Thoracentesis Hollow needle or cannula is inserted into the pleural space to release air, allowing the lung to reinflate. Because pneumothorax is potentially life-threatening for a newborn, immediate removal of accumulated air by thoracentesis may be warranted. This procedure carries a risk of damaging the lung pleura with needle tracks as the lung reinflates. A chest tube can be inserted into the pleural space for complete resolution of the pneumothorax. Only can be performed by specifically trained personnel 16 17Normal Labor and Childbirth Occasionally a pneumothorax can be managed conservatively with observation and breathing oxygen enriched air to aid the reabsorption of the extra-alveolar gas. 18 Transient tachypnoea of the newborn Most newborns make the transition from fetal to Newborn life without incident During fetal life the lungs are filled with a serous fluid, During and after birth this fluid must be removed and replaced with air Passage through the birth canal during vaginal birth compresses the thorax,which help remove this fluid 19 TTN occurs when the liquid in the lung is removed slowly or in completely These infants present with respiratory distress normally restricted to tachypnoea alone with rates up to 120 breaths/min. Occasionally supplemental oxygen is required This condition is self limlted,usually resolved within days after birth 20 The most common predisposing factor for TTN is a caesarean section Although these babies tend to require initial care on a neonatal unit, their stay is usually of a short duration with the provision of oxygen and observation. 21 Chest X-ray: Increased interstitial markings wet lung 22 Infection/pneumonia pneumonia present with signs of respiratory distress in the newborn. All babies presenting with respiratory distress need to be treated for infection until there is proof to the contrary Pre-term infants have an immature immunological response and hence less resistance to infection 23 However, pneumonia presenting before 48hrs of age has normally been acquired either at or before birth where apresentation after 48hrs indicates a late onset infection possibly resulting from hospitalization. All infants with infection require antibiotics but their length of stay on a neonatal unit will vary depending upon the nature of the infection. 24 Patchy infiltrates (aspiration) Bilateral diffuse granular pattern Streaky Patchy infiltrates (aspiration) Bilateral diffuse granular pattern Streaky 25 Meconium aspiration syndrome Most often found in post date infants > 40 weeks, but may occur in infants >34 weeks Fetal asphyxia causes the passage of meconium into the liquor. Obstruction of large and small airways with aspirated meconium A baby can develop meconium aspiration syndrome if stimulated to breathe or gasp, either in utero,intrapartum,postpartum period 26 A significant number of births have meconium-stained liquor but only a few will cause the severe meconium aspiration syndrome, with its associated mortality that is seen in the NNU The initial respiratory distress may be mild, moderate or severe with a gradual deterioration first 1224hrs in the moderate or severe cases. The baby may present with cyanosis, increased work of breathing and a barrel- shaped chest 27 X-Ray Increased AP diameter Hyperinflation Atelectasis Pneumothorax 28 This accumulation can then lead to the rupture of the alveoli and cause the baby to develop a pneumothorax meconium has contact with the lung tissue a pneumonitis occurs and a fertile site for infection is created. Endogenous surfactant is also broken down in the presence of meconium. These infants will need full intensive care and ventilation to prevent further deterioration. 29 Respiratory distress syndrome respiratory distress syndrome (RDS) is used interchangeably with the diagnosis of HMD The disease occurs as a result of the insufficient production of surfactant maternal diabetes can also inhibit surfactant production. The 50% of babies born before 30 completed weeks' gestation experience RDS while 1% of all newborn babies may experience RDS 30 Surfactant is acomplex mixture of 6phosoholipid and 4protien, Begins at weeks of gestation, and gradually increases until birth ( good amount in unstressed infant at 36 W) produced by the type II epithelial cells to reduce the surface tension within the alveoli, preventing their collapse at the end of exhalation. Collapsed alveoli require much greater pressure and exertion to reinflate than do partially collapsed alveoli. 31 The introduction of surfactant therapy into neonatal care has significantly decreased the mortality and morbidity previously seen in RDS. Surfactant consists of several different types of proteins and phospholipids, which also help prevent infection and produce further surfactant. 32 The X-ray has a ground-glass appearance across the lung fields, while severe disease is represented by a white-out, the greater the density of the white out reflecting the severity of the disease Mild disease may need oxygen alone but the more severe will need surfactant and ventilatory support. The length of stay on the NNU is dependent upon the severity of the disease and the gestational age of the baby. 33 Decrease production of surfactant Hypoxia Acidosis Hypothermia Hypotension Hypothyroidism Diabetes Birth asphyxia Meconium aspiration syndrom Secondary surfactant deficiency Intra partum asphyxia Pulmonary infections Pulmonary haemorrhage Meconium aspiration syndrom Oxygen toxicity along with barotrauma or volutrauma to the lungs RDS occurs more common in the following individuals Male infants Infants born to mothers with diabetes Infants delivered via cesarean without maternal labour Second-born twins Infants with a family history of RDS RDS occurs less common in the following individuals Use of antenatal steroids Pregnancy-induced or chronic maternal hypertension Prolonged rupture of membranes Maternal narcotic addiction Physical findings Tachypnea Expiratory grunting (from partial closure of glottis) Subcostal and intercostal retractions Cyanosis Nasal flaring Extremely immature infants may develop apnea and/or hypothermia Normal chest x-ray RDS x-rays The incidence of RDS by GA Cardiac disease Cardiac defects affect 1% of births and can be divided into left-sided and right-sided defects. They account for 30% of congenital defects. 42 Right-sided lesions (CCHD) The most frequently seen lesions are transposition of the great arteries,tetralogy of Fallot, pulmonary atresia or stenosis These babies typically present as a blue baby. Their respiratory distress, if present, is mild and consists of tachypnoea alone. These babies will remain cyanotic in the presence of 100% oxygen. An urgent cardiac assessment will need to be sought. 43 Cyanotic Heart Disease Tetralogy of Fallot (TOF) Transposition of great arteries (TGA) Truncus Arteriosus Tricuspid Atresia Total Anomalous Pulmonary Venous Connection (TAPVC) 44 Tetralogy of Fallot Transposition of the Great Arteries Left-sided lesions(ACHD) The most frequently occurring left-sided lesions are hypoplastic left heart syndrome and coarctation of the aorta. These frequently present with neonatal heart failure. Initially the baby may appear irritable, lethargic, sweaty and not interested in feeding. The presence of effortless tachypnea may be seen. This tachypnea is characterized by the lack of any other sign of respiratory compromise Acyanotic Heart Disease Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), Patent Ductus Arteriosus (PDA), Atrioventricular Septal Defect (AVSD). 48 Ventricular Septal Defect (VSD) Atrial Septal Defect (ASD) Tricuspid Atresia Hypoplastic Left Heart Syndrome What to anticipate in the neonatal unit The anxious and frightened parents will be confronted with a technological environment with an array of buzzers, bleeps, flashing lights and alarms. It is easy to lose sight of the baby behind the technology. However, all these machines and alarms will have a role to play in the care of the baby. 53 Respiratory care Babies showing signs of respiratory compromise require a further assessment by a paediatrician or nurse practitioner. This may necessitate an admission to the NNU for continuous supervision and observation of their respiratory status. 54 They require the skills of practitioners who can monitor and assess their critical changes in status and implement the care that is required. To assist in these observations the use of saturation monitors, transcutaneous monitors, arterial catheter readings and blood gas monitoring are used. When satisfactory oxygenation is not being achieved, the baby may need additional oxygen. This can be delivered via nasal cannula, into the incubator or into a headbox, creating an oxygen-enrich ed micro-environment 55 Some babies will need additional ventilatory support to assist the maintenance of an adequate airway or to maximize their respiratory status 56 Neonatal ventilator 57 Definition Method to mechanically assist or replace spontaneous breathing when patients cannot do so on their own. The goal of MV is to improve oxygenation, ventilation, and decrease work needed for effective breathing so used until pt. can resume breathing on his/her own. 58 Type of MV: Positive pressure ventilation (Currently used) Increasing the pressure in the patient's airway through an endotracheal or tracheostomy tube and thus forcing additional air into the lungs Negative pressure ventilation (Historically common ) Creates a negative pressure environment around the patient's chest, thus sucking air into the lungs Pt must have adequate lung elasticity 59 Three types of positive pressur ventilators: 1-Pressure Cycled Ventilators: Rarely used. Used post-anesthesia, for short periods, and for resp. therapy. Pushes air into lungs until a predetermined airway pressure is reached. Tidal volumes and inspiratory times variable. 2-Time Cycled Ventilators : Used for infants and neonates. Tidal volumes and pressure is variable according to pt and/or ventilators. Vent. Pushes air into lungs until preset time has elapsed. 60 3-Volume Cycled Ventilators: Pushes gas into lungs until a preset volume is delivered regardless of pressure needed to deliver volume. Pressure limits set so as not to over expand the lungs. Constant Tidal volume delivered regardless of compliance of lungs or chest wall, and airway resistance (advantage) 61 CMV (Controlled mandatory Ventilation ) Conventional ventilation techniques are increasingly being delivered in ways similar to the natural breathing patterns. During the critical phase of the illness the ventilator may deliver preset rates and pressures only. However, as the baby stabilizes and improves, ventilators are now able to mimic the babies' individual rates, pressures or lung volumes thereby minimizing the associated lung trauma. Advantage: rests muscles of respiration Disadvantage: awake patient tends to buck the ventilator thus requires sedation and neuro- muscular blockade. 62 SIMV( Synchronized Intermittent Mandatory Ventilation ) Preset tidal volume, at a preset rate (a minimum backup) Additional spontaneous breaths at tidal volume and rate determined by patient Often used with pressure support to decrease the work of breathing Potential Advantages Better patient-ventilator interaction Less hemodynamic effects Potential disadvantages Higher work of breathing than CMV or PC 63 CPAP (continuous positive airway pressure ) Nasal continuous positive airway pressure (NCPAP) is used either as a therapy for moderate disease or as weaning tool. Use of positive pressure throughout respiratory cycle for pts who are breathing spontaneously. Keeps alveoli open during inspiration and prevents alveolar collapse during expiration. The aim is to avoid the trauma of an endotracheal tube and the bronchiolar damage from ventilation. 64 Complications of mechanical ventilation Nosocomial pneumonia Barotrauma - parenchymal damage due to high airway pressure/volume Hemodynamic compromise - due to high intrathoracic pressure and reduced venous return (hypotension) Decrease lung elasticity (Ventilator Dependence) Tension pneumothorax 66 Alternative ventilation options HFOV (high freguency oscillated ventilation) NO ( Nitric oxide) CNEEP ( Continuous nasal end expiratory pressure) ECMO ( Extracorporeal membrane oxygenation) 67 NOTES: Cardiac failure in a neonate is rare and the majority of arrests are respiratory in origin. Nevertheless, neonates may require support to maintain an efficient and effective heart beat Normally a respiratory cause is considered first before other explanations are explored. Continuous observation and supervision of the cardiac parameters will be needed, which can be achieved using either an indwelling catheter or non- invasive monitoring. 68 A bradycardia (a heart rate dropping to below 80) may be a sign of various influences such as a blocked endotracheal tube or sepsis Neonates may need additional cardiovascular support through medication 69 The role and benefits of breastmilk are clearly established Premature baby has an immature gut can give rise to feeding difficulties. A pre-term baby has little nutritional reserves and will need supplementation The majority of such babies will receive a glucose- based intravenous infusion. can give milk feeds via a nasogastric, orogastric or nasojejunal tube and increase the volumes as the baby's condition allows immature babies need a cautious introduction to milk, whether expressed breastmilk or formula feeds, as these infants are susceptible to necrotizing enterocolitis (NEC). 70 TPN is normally administered through a central line, either a longline or umbilical catheter. TPN typically contains amino acids, fat, carbohydrates, minerals, vitamins and trace elements to prevent the depletion of these essential components TPN have some undesirable side-effects upon the liver, giving rise to a conjugated hyperbilirubinaemia or cholestasis. 71 Necrotizing enterocolitis NEC has mild symptoms as a painful distended abdomen, blood in the stool and poor food tolerance. However there may be more acute pathology; symptoms may include air within the gut wall, leading to a perforation, hypovolaemic shock and disseminated intravascular coagulation. delaying feeding and administration of antibiotics can alter the dominant gut flora,This can lead to a proliferation of anaerobes and bacterial invasion into the gut wall lead to episodes of hypoxia Treatment is initially with antibiotics and medical management 72 neonate has an increased susceptibility to infection owing to the immaturity of the neonatal defence mechanisms Their responses to infection take longer as the organisms are new and not recognized by the memory cells. The complement cascade, a supplementary defence mechanism of plasma proteins, remains inefficient the skin are immature. Consequently the neonate has a reduced ability to fight infection 73 neonatal infection, whether prenatal or postnatal, continues to contribute to neonatal mortality hence the use of prophylactic antibiotics is widespread throughout developed countries A baby needs the environment to require minimal metabolic activity to maintain temperature stability Babies for whom an inadequate thermoneutral environment is achieved have an increased mortality and morbidity The neonate experiences a number of stressors within the neonatal environment 74 The importance of attachment for the future relationship between the parents and their baby has been recognized identifies factors that can influence a family's reactions to a child's hospitalization and lists them as the severity of illness and threat to the baby, previous experiences, familiarity with medical practice and procedures, available support systems, coping strategies, family stresses The midwife and nursing team can assist the parents to overcome difficulties by improving the quality of their communication for parents and by facilitating the parents' easy and frequent access to their baby 75 The parents should be enabled to develop the skills needed to care for their own baby and be given the information and empowerment to deliver that care, therefore ensuring that the care is family centred, rather than medical and technology focused 76 Thank you