1
Q
What are the 4 newborn physiological adaptations required at birth?
A
- respiratory system
- cardiovascular system
- thermal adaptation
- metabolic adaptation
2
Q
What factors can influence effective ventilation (4)?
A
- The infant must clear amniotic fluid from the lungs.
- Surfactant must be adequate.
- Respiratory musculature must be sufficient.
- The infant must establish a regular pattern of breathing.
- Pulmonary perfusion must match ventilation (VQ matching).
- Increased pulmonary blood flow must occur.
3
Q
What 4 factors are included for establishment of effective respiration at prior/during birth?
A
- catecholamine surge that occurs prior to the onset of labour,
- the postnatal decrease in 02 concentration,
-the increase in C02 concentration and - decrease in pH that trigger the respiratory centre,
- the mechanical squeeze on the chest as the infant moves through the vaginal canal, and
- further expansion of the lungs as the infant cries
4
Q
What are the profound changes that occur in the cardiovascular system during transition from fetal to neonatal life?
A
fetal circulation:
- high pulmonary vascular resistance (PVR) and
- low systemic vascular resistance (SVR),
- three shunts: ductus venosus, ductus arteriosus, foramen ovale
At birth:
- the umbilical cord is clamped and the placenta is removed as the organ of gas exchange (along with the ductus venosus), and therefore the lungs must take over this role.
- Fetal fluid must be absorbed and alveoli expanded in order for the lungs to effectively take over oxygenation.
- Mechanical compression of the chest during birth creates negative pressure, drawing air into the lungs, and positive intrathoracic pressure created when the newborn cries keeps alveoli open and forces remaining fetal fluid out of the lungs.
- As oxygen enters the lungs, the pulmonary vascular bed dilates, allowing for increased blood flow to the lungs and decreased pressure in the right atrium.
- The left atrial pressure exceeds the right atrial pressure due to increased pulmonary venous return to the left atrium and less blood flow to the right atrium, which leads to functional closure of the foramen ovale.
- Blood is now following the path of right atrium to right ventricle to lungs
After birth:
- SVR rises and PVR falls, causing a reversal of blood flow through the ductus arteriosus.
-Instead of bypassing the lungs, blood is now sent to the lungs.
- Closure of the ductus arteriosus is due to a rise in P02 concentration after birth and a decrease in circulating prostaglandin levels (from removal of the placenta).
- Closure of the ductus arteriosus happens gradually, with 90% of infants having full closure by 48 hours of age; therefore, in the first days of life, there may be some bidirectional shunting of blood, depending on the levels of PVR and SVR
5
Q
How is oxygenated blood delivered from placenta to fetus via umbilical vein in the fetal circulation?
A
- Some of this blood perfuses the liver and some of it bypasses the hepatic system through the ductus venous, a connection between the umbilical vein and the inferior vena cava (IVC).
- Once this oxygenated blood enters the IVC, it is mixed with de-oxygenated blood from the lower body and sent to the right atrium.
- Approximately half of this blood is sent directly to the left atrium through the foramen ovale, while the rest enters the right ventricle.
- The blood flow across the foramen ovale is due to high PVR, ensuring the pressure in the right atrium is higher than the left.
- Most of the blood that makes its way to the right ventricle is shunted across the ductus arteriosus directly into the aorta (again this is due to increased resistance in the pulmonary vessels).
- The remaining approximately 10% of the blood coming from the right ventricle perfuses the lung tissue.
6
Q
What makes newborns predisposed to heat loss (3)?
A
- they have a large surface area in relation to their body weight,
- limited body fat, and
- decreased ability to shiver to stay warm
7
Q
What are 3 of the processes that term infants have available to stay warm?
A
- increased muscle activity,
- non-shivering thermogenesis (burning brown fat),
- peripheral vasoconstriction
8
Q
Newborn still rely on caregiver to maintain thermoregulation, what happens if there were no caregiver support?
A
- infants will use up oxygen and glucose in an effort to produce heat;
- this yields lactic acid and
- can lead to metabolic acidosis, hypoglycemia, decreased surfactant production and poor growth.
9
Q
Where is Glycogen is stored for use after birth?
A
- liver
10
Q
Use of brown fat for heat production is called?
A
- non-shivering thermogenesis
11
Q
The use of glucose and oxygen to produce heat produces?
A
- lactic acid
12
Q
The connection between the umbilical vein and the inferior vena cava is called the?
A
- ductus venosus
13
Q
What signals the ductus arteriosus to close (2)?
A
- An increase in p02 and a
- decrease in prostaglandin signals the ductus arteriosus to close
14
Q
What is perinatal asphyxia or intrapartum hypoxia-ischemia?
A
- When organ of gas exchange fails (placenta or lungs)
- used to describe impaired gas exchange or inadequate blood flow to the fetus/newborn that occurs during labour and delivery
- hypoxia (↓pO2) and hypercapnia (↑pCO2)
- perinatal asphyxia puts all of infants organ systems at risk for damage due to hypoxia and decreased perfusion
15
Q
What are causes of asphyxia to occur prenatally (3)?
A
- pregnancy-induced hypertension (PIH), leading to poor placental function
- placental abruption
- compression of the umbilical cord
- low maternal 02 levels
- low maternal blood pressure
- inadequate relaxation of the uterus during labour
16
Q
What 2 cues might suggest presence of asphyxia in an infant in utero?
A
- Fetal heart rate decelerations
- Passage of meconium is also a clue to the presence of asphyxia.
17
Q
What disorders affect gas exchange in a newborn leading to asphyxia (3)?
A
- congenital diaphragmatic hernia
- sepsis
- congenital heart defects
- severe anemia
- low blood pressure
- respiratory problems that limit oxygen intake (meconium aspiration, severe RDS)
18
Q
What are 2 ways infant response to hypoxia to provide their organs with oxygen?
A
Alteration of blood flow:
- to provide those organs necessary for immediate survival—the brain and the heart—with as much oxygen as possible at the cost of non-vital organs (diving reflex).
- blood is shunted away from non-vital organs such as the lungs, intestines, kidneys, and peripheral vessels.
Tachycardia:
- increase in heart rate is a reflection of the heart’s effort to increase cardiac output in response to the decrease in blood oxygen levels.
- When the heart rate increases, the cardiac output and blood pressure are improved, therefore increasing perfusion and oxygenation
19
Q
When does infant switch from aerobic to anaerobic metabolism?
A
- when oxygen availability is compromised
- Hypoxia and asphyxia alter glucose production and utilization by requiring an increase in glycogeolysis to meet the increased metabolic and energy demands
20
Q
What is anaerobic metabolism?
A
- is less efficient than aerobic metabolism and requires significantly more glucose to create energy.
- This rapidly depletes the glucose reserves; this decreased energy production is often inadequate to maintain normal cell processes and leads to the accumulation of lactic acid, which causes metabolic acidosis
- Hypoxia will also lead to hypercapnia (↑CO2) due to the body’s attempt to bring in more oxygen and will result in respiratory acidosis
21
Q
How is asphyxia characterized?
A
- Asphyxia is a process characterized by inadequate/insufficinent gas exchange, leading to progressive hypoxia, hypercapnia, and acidosis, which may occur in utero or shortly after an infant is born.
22
Q
What causes inadequate gas exchange in utero (3)?
A
- pregnancy-induced hypertension
- abruptio placenta
- cord compression
- apnea at birth
- meconium aspiration
23
Q
What negative response to the pulmonary system as a result of infant having been asphyxiated (3)?
A
- Respiratory distress,
- meconium aspiration,
- persistent pulmonary hypertension,
- atelectasis,
- pneumonia
24
Q
What are 3 negative response to the cardiovascular system as a result of infant having been asphyxiated?
A
- Congestive heart failure,
- cardiogenic shock,
- hypotension,
- disseminated intravascular coagulation (DIC)
25
What are 2 negative response to the GI system as a result of infant having been asphyxiated?
- Feeding intolerance,
- necrotizing enterocolitis (NEC)
26
What are 2 negative response to the renal system as a result of infant having been asphyxiated?
- Decreased urine output,
- hyperkalemia,
- renal failure
27
What are 3 negative response to the central nervous system as a result of infant having been asphyxiated?
- Hypoxic-ischemic encephalopathy (HIE),
- periventricular leukomalacia (PVL)
- seizures,
- sometimes long-term neurological problems such as cerebral palsy and cognitive deficits
28
What nursing measures could you implement in order to prevent further asphyxia and to prevent the complications associated with asphyxia (3)?
- Immediate effective resuscitation with provision of warmth, ventilatory support, and maintenance of adequate circulation. Establishing spontaneous respirations, a normal heart rate, and correcting acidosis will prevent further brain injury.
- Assess for the effects of asphyxia: hypoxia, hypercapnia, acidosis, and hypoglycemia, which may show up in many ways, such as seizures, apnea, respiratory distress, intolerance of feeds (when started), and temperature instability.
- Closely monitor the infant’s vital signs (including blood pressure), oxygen saturation, blood work results, and urine output.
- Maintain the infant’s warmth—prevent cold stress.
- Ensure sufficient glucose intake—usually the infant is NPO, so an IV is initiated. Fluid intake may be restricted to 50–70 mL/kg/hr to prevent fluid overload (since renal function may be impaired due to hypoxia) and to prevent cerebral edema.
- Keeping the infant NPO will give the gut an opportunity to recover.
- Developmentally supportive and family-centred care is key!
29
What is meconium composed of?
- the first stool of the infant, is composed of material ingested in utero such as amniotic fluid, bile, mucous, and epithelial cells.
- Meconium is very thick and sticky, like tar
30
What is the difference in meconium aspiration in preterm (less than 32 weeks) vs full term infants?
- Preterm infants, particularly those less than 32 weeks gestation, rarely experience meconium aspiration as their guts contain very little meconium.
- Meconium aspiration is a common feature of perinatal asphyxia for full- and post-term infants
- Full- and post-term infants, in contrast, have large amounts of meconium in their colons.
31
What are 2 reasons that post-term infants are at risk for meconium aspiration?
- They have large amounts of meconium in their gut.
- These infants can be quite large (if they continue to grow in utero) and consequently suffer second stage problems arising from their larger size.
- If they have not been growing—because the placenta has been deteriorating—they will likely be stressed and may already be experiencing hypoxia, causing meconium passage
32
What is the steps when meconium is expelled into amniotic fluid?
meconium expelled into amniotic fluid -> hypoxia causes infant to gasp -> delivery -> first breath -> meconium aspiration -> hypoxia
- When full- and post-term fetuses experience hypoxia, their gastrointestinal wall relaxes and meconium is expelled into the amniotic fluid
- if the hypoxia is severe, the infant can gasp (even in utero), causing the meconium to be aspirated into the airways.
- When the infant begins breathing at birth, the meconium is further aspirated, leading to severe respiratory distress, hypoxia and hypercapnia
33
What are 4 ways meconium aspiration causes hypoxia in the neonate?
- airway obstruction: The glottis, trachea, and smaller airways are physically obstructed, resulting in atelectasis, air trapping and alveolar collapse.
- surfactant dysfunction: Meconium deactivates surfactant and may inhibit surfactant synthesis, which results in atelectasis throughout the lungs.
- increased pulmonary vascular resistance: This occurs as a result of the hypoxia/asphyxia, which can result in the ductus arteriosus staying open (right-to-left shunting) and the maintenance of fetal circulation.
- chemical pneumonitis: The contents of the meconium can irritate the airways and parenchyma, causing the release of cytokines, which results in inflammation of the airways.
34
What is the comparison of normal and impaired pulmonary blood flow (4)?
Normal pulmonary blood flow:
- closure of ductus arteriosus
- closure of foramen ovale
- pulmonary vasodialtion
- increase PO2
Impaired Pulmonary blood flow:
- patent ductus ateriosus
- (+/-) patient foramen ovale
- pulmonary vasoconstriction
- decrease PO2
35
Why are full term infant more vulnerable to persistent pulmonary hypertension of the newborn (PPHN) than preterm infant?
- because the muscles in the walls of their pulmonary vessels are well developed and are highly sensitive to hypoxia
- Preterm infants, while they can and do experience asphyxia, are less likely to develop PPHN because their pulmonary vessels are less muscularized and less sensitive to hypoxia
36
Why is the development of PPHN adds to infants vulnerability?
- a rising blood oxygen level is critical to successful transition.
- Recall that in utero, low pO2 levels help to keep the ductus arteriosus open and cause pulmonary vasoconstriction.
- Together, a patent ductus arteriosus and pulmonary vasoconstriction shunt blood away from the lungs (right-to-left shunting).
- During transition, rising pO2 begins to close the duct and causes pulmonary vasodilation, lung fluid is absorbed, and the lungs take over the process of gas exchange (which was previously done by the placenta).
- In the presence of hypoxia, pulmonary vasoconstriction continues, which in turn will maintain a patent ductus arteriosus that can lead to pulmonary hypoperfusion
37
What are the ABCs of resuscitation as per NRP?
A - airway - position and clear
B - breathing - stimulate to breath
C- circulation - assess heart rate and colour
38
What is the APGAR score and when is it done?
Appearance: colour
Pulse: heart rate
Grimace: reflex irritability
Activity: muscle tone
Respiration: breathing
- An infant is given a score in each category at 1 and 5 minutes (and sometimes at 10 minutes).
- The highest score possible would be 10 (a score of 2 in each category)
- Apgar score quantifies the infant’s response to extrauterine life and resuscitative measures.
39
What are the normal range for capillary blood gas?
- pH: 7.35–7.45
- bicarb: HCO3- 20–26
- pCO2: 35–45
- PaO2: 50–80: aterial
-PcO2:
- bases excess: BE -4 –+4
high CO2: respiratory acidosis: hypoventilation
low bicarb and low base excess: metabolic acidosis
40
Why is management of perinatal asphyxia involves every organ system?
- Management of perinatal asphyxia involves every organ system because perinatal asphyxia has multiple organ system sequelae.
- Every organ system is vulnerable to damage from hypoxia as a result of perinatal asphyxia and must, therefore, be supported.
41
How would you advise Meagan to proceed with her assessment of Vinod? What does she need to pay attention to?
- Assessment during resuscitation is based on the NRP sequences of airway, breathing, and circulation.
- In these sequences, position, colour, HR, respiratory rate, and effort and oxygen saturation are important parameters.
- Assessment must also be multi-system. Once an infant is resuscitated and stabilized, a baseline assessment must be done with a view to collecting key information in each system. This can be done by a systems approach or from a head-to-toe approach
42
What are the 3 interrelated but separate processes that blood gas analysis assesses?
- oxygenation
- ventilation
- acid-base homeostasis
43
How is oxygenation assessed?
- Oxygenation is assessed by how much oxygen the lungs are delivering to the bloodstream, indicated by the pO2 and oxygen saturation:
pO2 measures dissolved oxygen (3% of total oxygen)
- normal values for pO2 are: arterial sample = 50–80 mmHg, capillary sample = 40–60 mmHg
***arterial pO2 values are much more accurate than capillary pO2 values
O2 sat measures oxygen carried on hemoglobin (97% of total oxygen)
- normal range for O2 saturation is 88%–95%
- pulse oximetry should be used instead of capillary pO2 values (as they are not as accurate as arterial values)
44
How is ventilation determined?
- Alveolar ventilation is determined by the pCO2 level.
- Carbon dioxide is very sensitive to minute ventilation, which is the volume of air inspired and exhaled in a minute.
- Minute ventilation (tidal volume × rate) and, in particular, tidal volume (volume of air moved with each breath) is affected by the functioning of the pulmonary system.
- Normal values for pCO2 are 35–45 mmHg.
- Hypoventilation leads to a buildup of CO2:
A high amount of CO2 in the bloodstream, such as when ventilation is impaired, decreases the pH as excess carbon dioxide combines with water to form carbonic acid, creating respiratory acidosis.
- Hyperventilation leads to a decrease in CO2:
A low amount of CO2 in the bloodstream, usually caused by over-ventilation, will cause a respiratory alkalosis.
45
What is acid-base homeostasis? Normal range for pH?
- Acid–base homeostasis is the balance of acid to base necessary to keep the blood pH level normal.
The acid–base balance of an infant’s blood is reflected by the pH:
- Normal range for pH is 7.35–7.45.
- A pH less than 7.35 indicates acidosis.
- A pH more than 7.45 indicates alkalosis.
46
What is respiratory acidosis caused by?
Caused by:
- too much CO2, which combines with water to form carbonic acid, which in turn drops the pH
- hypoventilation
47
What is metabolic acidosis caused by?
Occurs with hypoxia and/or poor perfusion caused by:
- failure of the kidneys to eliminate the hydrogen ions they normally eliminate from the body via urine
- failure of the kidneys to reabsorb the bicarbonate they normally recycle back into the body
- too much lactic acid
- anaerobic metabolism produces a lot of lactic acid as a by-product, which lowers the pH
48
What is Respiratory Alkalosis caused by?
Alkalosis (state of too much base or too little acid) is:
- caused by too little carbon dioxide
- occurs with hyperventilation (either spontaneously or by a mechanical ventilator set with too high a rate)
49
What is metabolic alkalosis caused by?
- loss of acid through gastric suctioning
50
What is seizure accompanied with?
- accompanied by abnormalities of gaze or extraocular movement
51
What is the difference between seizure and jittery?
- Seizures are not stimulus sensitive—if you touch an infant and the infant responds with his/her arm shaking, the infant is jittery, not having a seizure.
- The dominant movement in a seizure is clonic jerking, in that the movements have a fast and slow component.
- Seizure movements will not stop if you flex the affected limb, while jitteriness will stop.
52
What should be documented if a seizure was witnessed (4)?
- time of onset and duration of seizure
- preceding activity, that is, at the end of a feed
- type of movement, that is, cycling, twitching
- body parts involved, that is, right arm
- change in level of consciousness/alertness
- change in vital signs
- post-seizure status—alertness, vital signs, tone
53
What are some causes of seizures (3)?
- intracranial hemorrhage (ICH)—responsible for up to 16% of seizures in infants
- intraventricular hemorrhage (IVH)—also often caused by asphyxia and/or hypoxia and common in preterm infants
- metabolic disturbances—hypoglycemia, hypocalcemia, hypomagnesemia, and hyperphosphatemia
- bacterial meningitis—often group B Strep
- viral encephalitis
- hypoxic-ischemic encephalopathy (HIE)—the most common cause of seizures in term infants, accounting for 60%–65% of seizures; often caused by intrapartum hypoxia-ischemia, which leads to decreased blood flow to the brain, resulting in areas of ischemic damage
54
What should a nurse do if suspect infant is having a seizure?
- Stay with the infant and observe him/her closely.
- If the infant is apneic or shows signs of respiratory distress, provide oxygen and ventilation as necessary.
- Attempt to stop the movement by gently touching or flexing the involved extremity—this will distinguish seizures from jitteriness.
- Document the seizure, noting preceding events or disturbances, exact description and type of seizure activity, duration of seizure, and condition of infant during and following the seizure.
- Report the seizure activity, specifying why you felt this was a seizure and not a normal movement or jitteriness.
- Review results of diagnostic tests to determine the cause of seizures.
- Give medications as ordered to control the seizures.
- Ensure the parents are informed of the seizure and provide support to them.
- Support and comfort the infant during and after the seizure.
55
How should a nurse facilitate family-centered care for infant and family?
- Provide the parents with emotional support and factual information about what is happening with Vinod. Keep in mind you may need to repeat the information several times.
- Offer to contact family members/friends who can provide support for the parents.
- Provide Ranjeet and Jason with information about where Vinod is going: the specific address of the hospital, the phone number of the NICU he is being transferred to, directions as to how to get to the new hospital, any information about the unit (for example, give them an information brochure/pamphlet about the unit if available).
- Talk with Ranjeet’s postpartum nurse and discuss the feasibility and appropriateness of obtaining a discharge order for Ranjeet so she can accompany Vinod to the tertiary centre.
- Discuss with the physician in charge of transferring Vinod or the Infant Transport Team the possibility of Ranjeet accompanying Vinod in the ambulance.
- Encourage Ranjeet and Jason to hold/touch/stroke/talk to Vinod while awaiting transfer—skin-to-skin contact is ideal!!
- Acknowledge any feelings of fear, anxiety, grief, and so on expressed by Ranjeet and Jason, and encourage them to express their feelings if they want. Validate that their feelings are normal.
- Many parents have feelings associated with loss, such as the loss of a perfect pregnancy and birth experience, the loss of a healthy baby, as well as the loss of the experience of bonding and breastfeeding.
- Loss of a normal birth coupled with potential transport away from the birthing hospital results in a separation that complicates the grief response.
- Provide a private place in NICU (through the use of screens, curtains, and so on) where Vinod and his parents can be without the curious eyes of others observing their every move during this stressful time.
- Provide Ranjeet and Jason with a photograph of Vinod (many units have a camera available for just this purpose).
- Discuss with Ranjeet her plans for feeding Vinod, that is, whether she’s planning to breastfeed Vinod. Hopefully Meagan or her postpartum nurse has already talked with her about this and if she is planning to breastfeed, she is starting to express her milk (pump).
56
What are some of the factors that remove control from parents who have a baby admitted to the NICU?
- The environment of a typical NICU—the equipment, the noise, the number of people
- The lack of a normal typical routine that occurs with a newborn who doesn’t have any special needs—infants usually are in the room with their mothers, the main focus is on how to care and feed the infant, there is lots of happiness, and so on; in contrast, holding, caring for, and feeding the infant in NICU is often limited
- Fear of death and disability of the infant—the loss of the perfect infant
- Lack of knowledge about what is happening to their infant
57
What are 3 to support Sarah developmentally (DCS) during procedure?
- best practice to always have two-person blood draws, the lab technician or RN who is drawing the blood and another person whose job is to support the infant through the procedure.
Other possible ways to support Sarah developmentally:
- are to provide sucrose drops during painful procedures,
- dim the lights and
- decrease noise, and
- offer skin-to-skin contact as early as possible
58
What is SGA caused by (3)? increased risk for (3)?
Caused by:
- maternal infection
- genetic abnormalities
- placental insufficiency
Increased risk for:
- hypocgylcemia/hyperglycemia
- temperature instability
- NEC
59
What is LGA caused by (3)? increased risk for (3)?
Caused by:
- larger parents
- weight gain during pregnancy
- maternal diabetes
Increased risk for
- problems with glucose regulation
- hypogylcemia
- respiratory distress
- hyperbilirubinemia
60
What are the patterns of illness?
-perinatal asphyxia
- pretrem birth
- NICU
MSOE --> can lead to MODS --> can lead to MSOF (death or chronic MODS)
- MSOE: multisystem organ
- MODS: multiorgan dysfunction syndrome
- MSOF: multisystem organ failure
61
What is important during the transition from intrauterine to extrauterine life (3)?
- first breath is critical
- respiration must be established
- extrauterine adaptation must occur in all systems
62
What is jaundice?
- yellowing of the skin
- physiologic: usually 24 hours after birth
- pathological: serum bili above 5mmol/L
63
What is the difference between Unconjugated vs conjugated bili?
Pathological: serum bili ↑ above 5mmol/l :
- Unconjugated: red blood cells breakdown
- Conjugated bili: unconjugated to conjugated in liver
64
How does oxygenated blood flow in fetal circulation?
- oxygenated blood enter umbilical vein
from placenta
- goes through the ductus venosus
- travels up the inferior vena cava
- enters R. atrium
- goes through the foramen ovale
- to the L. atrium
- then to the L.ventricle
- out to the ascending aorta to supply nourishment to brain and upper extremities
65
How does deoxygenated blood flow in fetal circulation?
- enters superior vena cava
- into R. atrium
- to R. ventricle
- into the pulmonary artery where some of the blood goes to the lungs to supply oxygen and nourishment
- also flows from the right ventricle through the ductus arteriosus
- where it enters the descending aorta (some blood goes to the lower extremities)
- then back to the placena
66
What are the 3 fetal shunts and their job?
ductus venosus:
- fetal blood vessel connecting the umbilical vein to the inferior vena cava
- allows oxygenated blood from the placenta to bypass the liver.
- Plays a critical role in shunting oxygenated blood to the fetal brain with DA and FO.
- carries mostly high oxygenated blood
foramen ovale:
- shunts highly oxygenated blood from right atrium to left atrium
- A foramen ovale allows blood to bypass the lungs
ductus ateriosus:
- right to left shunting
- pulmonary artery (high pressure) to aorta (low pressure)
- pulmonary vascular resistance is high
67
What are 5 happens after birth (cardiopulmonary system)?
- First breaths of air the baby takes at birth → fetal circulation changes
- Larger amount of blood → to the lungs to pick up oxygen
- Ductus arteriosus begins to wither and close off
- Circulation ↑ in lungs and more blood flows into the left atrium of the heart
- increased pressured causes foramen ovale to close and blood to circulate normally
68
What is critical congenital heart disease (CCHD)? 3 examples of CCHD?
- Severe and often duct-dependent lesions that require early intervention
Example of CCHD include:
- hypoplastic left heart syndrome,
- transposition of the great arteries,
- tricuspid atresia,
- tetralogy of fallot,
69
How is CCHD screening done (5)?
- Infants born at or above 34 weeks gestation
- Pulse oximetry between 24-36 hours of age
- Measure preductal (Rt hand) and postductal (either foot) 02 sats
- 02 sats 95% or > Rt hand and foot
- 3% or less between Rt hand and foot
70
Why is CCHD not screened for infants <34 weeks?
- Prems often receive 02
- 02 sats measured but no pre/post ductal measurements
- Difficult to interpret 02 sats due to lung disease and other illnesses
71
What if infant failed CCHD screening?
- repeat 1 hour after first initial screen
- max total of 3 screens with 1 hour between each screen
- notify doctor
72
What are 3 causes perinatal asphyxia antenatal? Intrapartum? Postpartum?
antenatal
- Pregnancy induced hypertension,
- maternal respiratory disease,
- maternal cardiac disease
intrapartum:
- Placenta previa,
- abruption,
- cord accident,
- prolonged second stage
postpartum:
- Meconium aspiration,
- CNS depression,
- pulmonary disease,
- sepsis,
- shock,
- congenital anomalies
73
What are 3 consequences of perinatal asphyxia (O2, CO2, pH)?
- Hypoxia
- Hypercapnia
- Acidosis (respiratory and metabolic)
74
What are 3 multisystem that perinatal asphyxia effects?
- HIE,IVH, PVL
- RDS, MAS
- PPHN, PDA
- NEC, AKI
- Hypoglycemia
- Hypothermia
- Hyperbilirubinemia
75
What is the difference between hypoxia and hypoxemia?
- Hypoxemia: ↓amount of 02 in the blood
- Hypoxia: Decreased amount of blood in the tissues
76
What is hypecapnia? 3 causes of hypercapnia?
- Too much C02 in blood
Amount of C02 in the blood is the result of:
- Body’s metabolism (production)
- Alveolar ventilation (excretion)
causes:
- lung immaturity
- apnea
- inadequate ventilator settings
- skeletal muscle weakness
- seizure
- sedation
77
What is acidosis? 3 cause metabolic acidosis and respiratory acidosis?
- pH < 7.35
- An increased acidity in the blood and other body tissues
metabolic acidosis:
- hypoxemia
- Hypotension
- Poor tissue perfusion
- Anemia
- Sepsis
- Respiratory distress
respiratory acidosis:
- inadequate alveolar ventilation: depression of breathing center in the brain
- Upper airway obstruction
- Stiffness of the chest wall
- Significant ventilation/perfusion imbalance
78
How does fetus/infant respond to asphyxia (2)?
Fetus or infant attempts to ↑ cardiac output by ↑ their heart rate:
- Inability to increase stroke volume
Peripheral vasoconstriction
- Maintaining blood flow to heart, brain and adrenals “diving reflex”
Eventually fails
- Acidosis, bradycardia and hypotension will result
79
What is passage meconium a marker for?
- Passage of meconium in utero is a marker for antepartum or intrapartum asphyxia
episodes of asphyxia:
- Sphincter relaxes releasing meconium into amniotic fluid
- During subsequent asphyxia episodes infant gasping→ aspiration meconium
80
What are signs of meconium?
may be stained greenish or yellowish appearance if the meconium was passed a considerable amount of time before
- The infant’s skin,
- umbilical cord, or
- nailbeds
81
What are 5 signs and symptoms of meconium aspiration syndrome MAS?
- Rapid or labored breathing
- Cyanosis
- Slow heartbeat
- A barrel-shaped chest
- Low Apgar score
82
What are 3 risk factors of MAS?
- Difficult delivery
- Advanced gestational age
Maternal:
- Diabetic
- Hypertension
- Chronic respiratory or cardiovascular disease
- Heavy smoker
- Umbilical cord complications
- Poor intrauterine growth
83
What does persistent pulmonary hypertension of the newborn (PPHN) result in?
- Low p02
- ↑ PVR
- PDA, PFO remain open
- Right → left shunting
- ↓ pulmonary blood flow
- cyanosis
84
What happens if pulmonary vascular resistance (PVR) remains high after birth? Causes?
- PPHN
- Tachypnea,
- retractions,
- cyanosis
- Low partial pressure of arterial oxygen (Pa02) despite high oxygen
High PVR forces blood through fetal shunts which causes:
- Murmur
- Hypoxia,
- acidosis
85
How is PPHN managed / preventing high PVR (3)?
- Oxygen Administration (vasodilator)
- Respiratory support
- Minimal stimulation
- Administering sedation and muscle relaxants * Surfactant administration
- Inhaled nitric oxide administration
- Monitoring arterial blood gas results
86
What are the compensatory and decompensatory responses to hypoxia?
compensatory responses:
- tachypnea
- tachycardia
- blood flow redistribution
Decompensatory responses:
- A,B and D’s
- decrease cardiac contractility
- hypotonia, decreased alertness * hypothermia
- GI, liver, GU, skin ischemia
- decrease hematologic and immunologic functioning
87
What are some central nervous system prematurity in preterm infants (3)?
- no stored glycogen, high oxygen needs
- fragile blood vessels
- weak blood brain barrier
- blood flow pressure passive
- poor differentiation
- poor autonomic regulation
- periventricular area growing rapidly early in gestation
- cerebral cortex dominant later in gestation
88
What happens to infant when experiencing respiratory dysfunction?
- Blood flow is redistributed to ensure the heart, adrenals and the brain get sufficient oxygen
- ↓ blood to gut, kidneys, liver, lungs, skin, and limbs get less blood
- Tachypnea & tachycardia are compensatory responses
- Tiring and increasing hypoxia leads to apnea, bradycardia and desaturations
- All organs are experiencing hypoxia, acidosis worsens, cardiac performance worsens
- Vicious downward spirals → multiorgan effects and damage
89
What are the composition of body fluids?
- body water -> extracellular (33%) + intracellular (66%)
- extracellular --> interstitial (25%) + plasma (8%)
90
What happens fluids in infant after birth?
- After birth, there is efflux of fluid from the intracellular fluid (ICF) to the extracellular fluid (ECF) compartment
- This increase in the ECF compartment floods the neonatal kidneys eventually resulting in a sodium and water diuresis by 48-72 hours
- Loss of this excess ECW results in physiological weight loss in the first week of life.
91
What kind of morbidities is failure to lose extracellular fluid (ECF) in infants (3)?
- patent ductus arteriosus (PDA)
- necrotizing enterocolitis (NEC)
- chronic lung disease (CLD)
- Pulmonary edema
- Chronic heart failure
- Renal failure
92
Whats the principle of fluid and electrolyte balancing?
- Total body water (TBW) equals intracellular fluid (ICF) plus extracellular fluid (ECF)
- ECF equals intravascular fluid (plasma and lymph in the vessels) plus interstitial fluid (between cells)
Water is the main component of the human body
- Adults 60 % water
- Term infants 80 % water
- Preterm infants (23 weeks) 90% water
- fetus 100% water
93
Where do the 3 mandatory losses of water happens in infants (sensible water loss)?
- kidneys: urine
- GI tract: stool and NG/OG drainage
- cerebral spinal fluid: ventricular drainage
94
What is insensible water loss (IWL) infant?
- Evaporation through the infant’s skin: 66% of IWL
- Evaporation through the infant’s respiratory tract: 33% of IWL
- Term infant: can lose 20 mL/kg/day
- Preterm infants: 1000 – 1500 grams – 40-60mL/kg/day
- infant <1000 grams: 60 – 80mL/kg/day
95
What other ways are IWL happen/increased (3)?
- Increased respiratory rate
- Conditions with skin injury
- Surgical malformations
- Increased body temperature
- High ambient temperature
- Use of radiant warmer and phototherapy
- Decreased ambient humidity
- Increased motor activity, crying
96
What are ways insensible water loss (IWL) is decreased by (2)?
- Use of incubators
- Humidification of inspired gases via CPAP or ventilators
- Increased ambient humidity
- Thin transparent plastic barriers
97
What are the fluid requirements in preterm? term?
Preterm
- Calories: 110–120 kcal/kg/day and 150 kcal/kg/day catch up
- Fluid: 60–150 ml/kg/day
Term
- Calories: 100 kcal/kg/day
- Fluid: 60-100 ml/kg/day
98
What can excessive fluid lead to /increased risk for (3)?
- RDS
- BPD: Excessive fluid can worsen therefore treat with diuretics to reduce pulmonary edema
- PDA: Volume overload can open ductus and worsen respiratory status
- HIE
99
When do infants require fluid increase (3)?
infants who are:
- <1500 grams
- Under a radiant warmer
- Receiving phototherapy
- Hyperthermia
- Experiencing diarrhea/vomiting
100
What kind of physical examination of infant reveal changes in fluid status?
- Color: pallor
- Perfusion: poor
- Activity: lethargic
- Mucous membranes: dry or sticky
- Fontanels: sunken
- Vital signs: low BP
- Urine output: low
- Lab results:
101
What causes high and low NA?
Hyponatremia:
- causes: can be due to excess free water or losses
- sign: lethargy, seizure
-treatment: restrict fluids
Hypernatremia
- causes: due to high water loss
- signs: lethargy, seizures, coma
- Treatment: increase fluids or restrict Na
102
What causes high and low postassium?
Hypokalemia
- Causes: diuretics, NG losses
- Signs: ECG changes, abnormal heart beats, lethargy
- Treatment: slowly correct IV or orally
Hyperkalemia
- Causes: iatrogenic, severe acidosis, ARF, RBC breakdown
- Signs: ECG changes, abnormal heart rhythms, death
- Treatment: D/C all K+ intake, Ca gluconate, sodium bicarb, Lasix, dialysis, exchange transfusion
103
What is the purpose of blood urea nitrogen (BUN)?
- normal: 1.8- 8.2 mmol/L
- purpose: Measure how well the kidneys are working
- too little: cause by malnutrition
- too much: caused from kidneys not working properly, dehydration
104
What is the purpose of creatinine?
- normal: 10 - 90mmol/L
- purpose: Is a protein produced by muscle and released into the blood
- too little: Caused by muscular dystrophy
- too much: With high BUN levels indicates problems with the kidneys, reduced renal blood flow, renal failure,
105
What is the purpose of bilirubin?
- Conjugated: <2mg/dL
- unconjugated: <150mg/dL
- purpose: Breakdown of RBC’s, Haeme of the RBC’s converts to bilirubin
- too little: Caused by caffeine, penicillin
- too much: lead to kernicterus and liver or gallbladder disease
106
What are some effects of environment on infants?
- Extrauterine functioning
- Sensory stimulation: noise, light, touch, smells, tastes
- Handling
- Pain, distress, stress
- Treatments and/or procedures
- Mechanical ventilation
- Supplemental oxygen
- Multiple caregivers
