Normal Pregnancy Flashcards
What are the first 3 steps in newborn resuscitation after delivery?
- warm and dry infant - also stimulates breathing
- ABC’s, grasp umbilical cord to check HR
- Evaluate infant for color and signs of resp. distress such as grunting, nasal flaring, chest retractions, tachypnea
What are the 5 parameters used to give an infant an apgar score?
HR Respiratory effort Muscle tone Skin color Response to stimulation
When are apgar scores given?
1, 5, and 10 minutes of life
What is the primary cause of cardiac arrest in neonates and infants?
hypoxemia
What are indications for bag mask ventilation in an infant?
apnea
HR
What is the ventilatory rate for a newborn?
40-60 bpm
What airway pressures can you use for the first breath after delivery?
30-40 cm H2O
What is the airway pressure you can use for an infant after a normal delivery?
15-20 cm H2O
What is the airway pressure you can use on an infant with diseased lungs after delivery?
20-40 cm H2O
What are indications for intubation of a newborn?
- prolonged bag and mask ventilation
- ineffective bag and mask ventilation
- tracheal suctioning
- severe prematurity
What would be the ETT size for a 6.5 lb (>3000 gms) infant?
4.0
What would be the ETT size for a 4.5-6.5 lb (2000-3000 gms) infant?
3.5
What would be the ETT size for a 2-4.5 lb (1000-2000 gms) infant?
3.0
What would be the ETT size for a 2 lb (
2.5
What should you do to optimize intubating position in an infant?
shoulder roll
When should you start chest compressions on an infant?
if after 15-30 secs of positive pressure with 100% FiO2 and HR is
How many inches should you compress the chest when doing CPR on an infant?
1/2-3/4
What is the compression ratio to breaths in an infant?
5:1
What should you do if you see meconium during delivery?
prevent stimulation to limit/prevent crying and decrease chance of meconium aspiration, infant immediately intubated and suctioned, suction while withdrawing ETT and may be repeated prn
Which phase of pregnancy does your CO increase the most?
first 13 weeks
How much does your CO increase with pregnancy?
40%
What causes the increase in CO with pregnancy?
increased HR by about 15 bpm
increased stroke volume by 25-30%
Why does CO/blood flow increase during pregnancy?
blood flow increases to uterus, breasts, and kidneys
When does uterine blood flow increase the most during pregnancy?
from week 32-40
What happens do the vasculature during pregnancy?
veins distend/dilate 150%
What happens to the epidural space during pregnancy?
veins are distended and engorged which decreases LA requirements
What EKG changes would you see with pregnancy?
left axis deviation, ST and T wave changes in lead III due to heart size increasing by 12% and heart displaced up and left and rotated laterally
What are hematologic changes with pregnancy?
hemodilution (40-50% increase in plasma volume and 20-30% increase in red cell mass)
increased fibrinogen and clotting factors
increased platelets
increased WBC in 3rd trimester and during labor
What is aortocaval compression?
pregnant uterus compresses the aorta and IVC in the supine position
What is supine hypotension syndrome?
fetus compresses aorta and IVC causing decrease in CO up to 24%, decreased uterine blood flow, fetal acidosis
What are symptoms of supine hypotension syndrome?
N/V
diaphoresis
possible changes in cerebration
fetal bradycardia
What is the treatment for supine hypotension syndrome?
wedge under right hip
tilting OR table 15-30 degrees to the left
using a mechanical uterine displacing table
What changes occur to the respiratory tract during pregnancy?
- vascular engorgement of nasopharynx, larynx, trachea, bronchi (vocal changes and difficulty breathing through nose can occur)
- progesterone-mediated relaxation of bronchial musculature (decreases airway resistance)
What changes occur to the lung volumes during pregnancy?
decreased FRC
increased TV
same TLC
What changes occur with gas exchange during pregnancy?
50% increase in minute ventilation decreased PaCO2 (avg. 32 mmHg) increased PaO2 (avg. 105 mmHg) compensatory decrease in bicarb O2 consumption increases 20%, 60% in labor
What are anesthesia implications regarding the pulmonary changes with pregnancy?
- smaller size ETT (6.0 or 6.5)
- avoid NG tubes
- beware of “Afrin addicts” - rebound effect
- rapid maternal desaturation occurs with apnea
- preoxygenation is key
- inhalation induction faster
What are mechanical GI changes that occur with pregnancy?
- small and intestines displaced cephalad (increased intragastric pressure)
- stomach is more vertically positioned
- angle of GE junction is changed
What are physiologic GI changes that occur with pregnancy?
- relaxation of the lower esophageal sphincter
- delayed gastric emptying
- delayed intestinal mobility
- gastric pH decreases
- increased incidence of heartburn
What are anesthetic implications regarding GI changes with pregnancy?
- all pregnant women considered full stomach >14 weeks
- aspiration risk increases
- avoid + pressure ventilation with mask anesthesia
- use RSI with GETA
- Consider use of Bicitra 30 mL PO, Reglan 10 mg IV, IV H2 blocker
What happens to serum cholinesterase levels during pregnancy and what does this mean regarding some of our drugs?
serum cholinesterase levels decrease which means we would give less drug (Ex: succ and ester LA)
What happens to the MAC during pregnancy?
decreases by 25-40%
What happens to the elimination half-life of most of our drugs during pregnancy?
longer elimination half-life due to increased volume of distribution
When do altered drug responses from pregnancy return to normal?
about 3 months post-partum
What is important regarding blood flow to the placenta?
not autoregulated, directly dependent on uterine perfusion pressure and number and size of spiral arteries
What are factors that decrease uterine blood flow?
uterine contractions uterine hypertonus maternal hypotension or hypertension aortocaval compression drug induced hypotension or hypertension
What are the mechanisms of placental transfer or drugs/substances?
passive diffusion (O2, CO2, drugs, electrolytes)
active transport (amino acid, H2O soluble vitamins)
facilitated diffusion (glucose)
filtration (water, some solids)
pinocytosis (immunoglobulins, proteins, macromolecules)
What are factors that determine drug concentrations in the uterine artery?
drug dosage route of administration maternal metabolism and excretion maternal protein binding maternal pH and drug pKa
What are drug properties that affect the rate of placental transfer?
lipid solubility
molecular weight
Do ionized substances cross the placenta?
No
Can you give benzos during pregnancy?
No, transfers to baby and can cause cleft lip and palate
When is the optimal time for elective surgery during pregnancy?
2nd trimester
What does gravida mean?
number of pregnancies
What do the numbers after parity mean?
1st number = term pregnancies
2nd number = pre-term pregnancies (20-37 weeks)
3rd number = spontaneous and elective abortions (
What causes variable decelerations?
cord compression
What causes early decelerations?
head compression
What causes accelerations?
normal physiological response to sympathetic stimulation
What causes late declerations?
placental insufficiency
