NURS2038 Week 1-2 Notes PDF

COMPLEX CARE OF THE NEONATE 1 Neonatal Thermoregulation 36.5°C to 37.4 ̊C, (may differ differ slightly at hospitals) Homoeostasis Thermoregulation for the newborn? Homeostasis is the balance between the body’s ability to I...

COMPLEX CARE OF THE NEONATE 1 Neonatal Thermoregulation 36.5°C to 37.4 ̊C, (may differ differ slightly at hospitals) Homoeostasis Thermoregulation for the newborn? Homeostasis is the balance between the body’s ability to In utero → baby receives heat from placenta & produce heat and lose heat. uterus. Intrauterine environment is thermoconstant at Sensors or receptors 37.7 ̊C. ↓ Birth room temp usually 21-25 ̊C → results in send messages to the control centre rapid heat loss due to wet skin. ↓ if required, effectors make changes in order to maintain stability. Hypothermia Hyperthermia Core tempt >36.5°C Core tempt 36.5° 3.Hypothalamic stimulation → causes Dress baby in warm clothes Routine observations as per noradrenaline to be released in BAT Temperature eg. Singlet and long leg/arm DR chart or per medical 26- 30 weeks Note: Avoid placing the temperature probe over brown fat deposit gestation and increases in the third areas. Use soft tissue areas (i.e. abdomen if supine). trimester (2-7% total body weight) It is found around the: Scapulae Kidneys Adrenals Neck Axillae Aorta  Effects of cold stress in the neonate Cold ↓ Activation of Non-shivering Thermogenesis ↓ (Metabolism of brown fat) ↓ Increased oxygen consumption Increased glucose use ↓ ↓ Increased respiratory rate Depletion of glycogen stores ↓ ↓ Pulmonary vasoconstriction Hypoglycemia ↓ Tissue hypoxia ↓ Peripheral vasoconstriction ↓ Anaerobic metabolism ↓ Metabolic acidosis Rewarming the infant in SCBU Birth, resuscitation Rewarm slowly (0.5 ̊C per hour/set cot temp and transport 1-1.5 ̊C above core temp) Delayed transition from Behavioural fetal to neonatal Oxygenation Nesting and positioning the neonate in a flexed changes circulation Vasoconstriction position → ↓surface area exposure → assist Hypotonia increase: pulmonary resistance which with thermoregulation Apnoea Lethargy Weak cry decreases Warming mattresses – ‘inditherm’→ for re- Poor feeding oxygenation warming Surfactant Monitor closely (vital signs every 30min) Glucose Per axilla 30/60 and continuous probe Increased uptake of Surfactant glucose = Production decreased measurement hypoglycaemia results in increased Blood pressure (vasodilation may lead Decreased energy for surface tension causing atelectasis and to hypotension) growth worsening hypoxia Heart rate and rhythm (bradycardia & arrhythmias common with hypothermia) Vasoconstriction Acidosis May need to check blood glucose Prolonged causing Increase in pulmonary decreased perfusion artery pressure causing May need oximetry resulting in anaerobic decreased blood flow to metabolism lungs COMPLEX CARE OF THE NEONATE 1 Fetal Circulation - Review BODY SYSTEM INTRAUTERINE EXTRAUTERINE CHANGES PFO closes with first breath Increase in SVR, once PVR reduces Cardiovascular Fetal circulation Closure of PDA Closure of PFONormal circulation Develops mostly in 30 trimester Major bronchi, bronchioles and alveoli Clearance of fetal lung fluid developed First cry Respiratory Lungs full of fluid Reduction in PVR Type 2 pneumocytes secrete surfactant Spontaneous breathing Fetal breathing Digestive enzymes released Digestive Swallowing amniotic fluid Passage of meconium Tolerance of milk Evaporative heat loss when vernix washed off? Antibiotic properties Integumentary Vernix production from 18 weeks Transdermal water loss for preterms Skeletal Moulding during birth Cortisol activates sodium pump that clears lung fluid Endocrine Placental supply of glucose and nutrients Catecholamine for adaptation (adrenaline and noradrenaline) Endocrine response to break down glycogen and fat to glucose IgM - 15 weeks gestation, 1% antibody IgA from breast milk, protects gut Lymphatic/Immunity producedIgG - 20 weeks gestation, maximum Vulnerable - late onset sepsis levels 32 weeks - term, crosses placenta Immunisations Blood flow increase to kidneys Urinary Renal harmone release Urine production Neutral Thermal Environment (NTE) The effect of hyperthermia Ideal environment in which an infant can maintain ↑Metabolic rate normal body temperature while metabolic rate ↑ Oxygen consumption (therefore also oxygen and glucose) is minimal. Dehydration↑from insensible water loss Peripheral vasodilation/ hypotension Fluid, Neutral Thermal Zone (NTZ) electrolyte abnormalities Environment created to maintain body temperature and Seizures minimise oxygen consumption and calorie expenditure. COMPLEX CARE OF THE NEONATE 1 Fetal Circulation Ductus Arteriosus Lung alveoli Shunt from pulmonary artery Continues to increase ↓ Develop until 8 years old to aortic arch ↓ Foramen Ovale allows blood to move from right ventricle Opening on the septum between the right ↓ and left atrium to circulation bypassing foetal lungs ↓ blood flows from right to left atrium ↓ Pulmonary arteries deoxygenated blood flows into the right Constricted – increased pulmonary atrium (via the inferior vena cava) resistance ↓ (5%-10% of cardiac output enters mixes with oxygenated blood (that has pulmonary circulation) come from placenta) Surfactant Fetal breathing movements Produced from 32 weeks From 11 weeks fetus develops chest decreases surface tension on alveoli muscles and diaphragm Lung fluid (different to surfactant) Promotes cell production and differentiation Catecholamine release during labour and birth → assists with absorption. Reabsorbed within 12-24 hours.) COMPLEX CARE OF THE NEONATE 1 Fetal breathing movements Clinical signs of the compromised newborn Is not breathing (Apnoeic) Poor muscle tone (floppy) Is Cyanosed Pale Has alveoli filled with clear fluid Persistent cyanosis (central) Is dependent on the placenta as the organ of gas exchange Depressed respiratory effort (gasping or apnoea) Pulmonary arterioles are constricted Bradycardia Pulmonary blood flow is minimal (high pulmonary vascular resistance) Blood flow is diverted across the foramen ovale and ductus Air or supplemental oxygen for arteriosus resuscitation? Blood is oxygenated in the placenta Potential adverse effects with 100% oxygen Oxygen rich blood is returned to the fetus from the placenta Increases oxidative stress via the unbilical vein (occurs when antioxidants levels are low - Imbalance between the production of reactive oxygen species and Blood returns →to the heart via the ductus venosus and and antioxidant defences). enters the inferior vena cava Increases damage to organs ↓ Increases mortality rates From the inferior vena cava → blood enters the right atrium of For term or near-term infants, begin IPPV with AIR the heart → most blood bypasses the right ventricle → is (21% OXYGEN). shunted through the foramen ovale → enters the left atrium. ↓ If requiring cardiac compressions, change to 100% From the left atrium of the heart → blood moves into the left OXYGEN. ventricle → delivered to the fetal tissues via the aorta. Begin with 30% Oxygen for preterm infants < 35 weeks ↓ Deoxygenated and nutrient poor blood is sent → back to the placenta via right and left umbilical arteries. ↓ Some blood in the right atrium → enters the right ventricle; blood in the right ventricle enters the pulmonary trunk → most of the blood bypasses the lungs through the ductus arteriosus. COMPLEX CARE OF THE NEONATE 1 When the newborn breathes a cascade of cardio respiratory events occur...... 1. Lungs expand with air, surfactant released 3. Pulmonary arterioles dilate and 2. Fetal lung fluid leaves alveoli Air 4. Pulmonary blood flow increases 5. Blood flows through the lungs to pick up oxygen 6. Blood oxygen levels rise 7. Cyanosis regresses 8. Infant becomes pink COMPLEX CARE OF THE NEONATE 1 Oxygen Saturations - Oximeter Follow target oxygen saturations on ANZCOR neonatal algorithm. Pre-ductal oxygen saturations can be collected on the Right hand of a newborn (NOT the left) Patent ductus arteriosus which can take 1-2 days to close. Brachiocephalic artery supplies oxygenated blood to head, neck and right side of body - therefore, less deoxygenated blood to this side (including R hand), more accurate reading of the oxygen in baby's body/ brain. Post Ductal oxygen saturations can be collected on the left or right foot Infant should be settled, NOT crying or feeding Once oximeter in place, wait a minimum of 30 seconds for a good trace. Oxygen saturation screening improves detection of critical congenital heart disease. Medications Adrenaline Normal Saline GiveifHR