*What are the benefits of the apgar scoring system?

*see chart on slide 8 and KNOW it

Reproducible numerical measurement

Objective criteria for neonatal resuscitation

Refocused outcome on neonatal as well as maternal well-being

1953 Virginia Apgar

What are the general changes in CO that occur during pregnancy for the mom?

25% increase by ______

50% increase by ______

100% increase by _____

150% increase in ______

Increases from the 5th week to a maximum at 32 weeks, where it remains stable until labor and delivery, and the immediate postpartum period.

25% increase by 8 weeks

50% increase by start of 3rd trimester

100% increase by active labor

150% increase in immediate postpartum period

How much is the CO increased in the immediate postpartum period?

Why?

150%!!!

d/t relief of aortacaval compression = increased venous return and decreased afterload per lec

How long does it take the CO to come down after delivery?

Decreases to prelabor values by 48 hours postpartum

Decreases to 10% above prepregnant values by 2 weeks

Returns to normal between 12 and 24 weeks postpartum

What is the major contributor to increased cardiac output:

 Heart Rate or Stroke Volume?

Stroke Volume

*see graph on slide 12

What is the change in stroke volume seen during pregancy?

____ % increase by __ weeks gestation 

___ % increase by term

20% increase by 4 weeks gestation

25-50% increase by term

20%

Development of the intervillous space, a low resistance vascular bed (exchange site for mom and baby's blood)

Vasodilation caused by prostacyclin, estrogen, and progesterone

Compression of the IVC occurs as early as _____ weeks gestation?

T/F Nonetheless, it is not necessary to utilize left uterine displacement here because the compression is minimal.

13-16 weeks gestation

False -- must utilize left uterine displacement!!

Increased femoral venous pressure

50% increased by 13-16 weeks

250% increase at term in the supine position

What maternal symptoms are seen due to Aortic compression in pregancy?

Fetal issues d/t this?

Aortic compression does not result in maternal symptoms

but may result in decreased uteroplacental blood flow

Per graph on slide 17 HR is increased during a contraction with a pt in pain, but if pain is removed/controlled as with an epidural the BP ________ and HR ______.

 See graph on slide 17 for explanation

List three factors affecting blood pressure.

HR is increased during a contraction when a pt is in pain, but if pain is removed/controlled as with an epidural the BP increases and HR decreases (compensatory).

See graph on slide 17 for explanation

Maternal Age

Parity 

Position 

In regards to parity (#of births) which women have higher BP? 

In pregnancy BP is highest in the _____ position, d/t _____.

nulliparous women have a higher BP than multiparous women

Supine

aortic compression

*note BP is higher in upper ext. d/t aortic compression and thus incr. afterload, but would be lower if measured in the lower ext.

What is a common extra heart sound heard in pregnant women.

What else might be noted with auscultation of a pregnant pt's heart? Why?

Loud S3 in many women

murmur

75% of women have tricuspid regurg and many also have mitral regurg d/t the increase in ventricular mass that leads to incompetency of the valve.

How much does plasma increase by term?

RBCs?

45%

30%

*thus pts have dilutional anemia

Estrogens increase plasma renin activity which enhances renal sodium reabsoprtion and water retention by the renin-angiotensin-aldosterone system

Progesterone also enhances aldosterone production

Increasing erythropoietin concentration due to progesterone, prolactin, and placental lactogen

beginning at 8-12 weeks 

11.6 g/dl and 35.5%

Just understand H&H is usually a bit lower than normal

Is oxygen transport compromised by physiologic (dilutional) anemia of pregnancy?

Why or why not?

NO

Increased maternal CO

Increased partial pressure of arterial oxygen

Right shift in oxyhemoglobin dissociation curve

Hemodilution is thought to be a protective mechanism against ?

There actually is a _____ relationship between Hgb and frequency of _____ _____.

placental thrombosis and infarction

direct

placental infarction

What are the changes in coagulation seen during pregnancy? (3)

The increase in coagulation (hypercoaguable state) may be a protective mechanism to deal with the ________________?

Incr. platelet consumption (some pts get thrombocytopena)

Marked increases in fibrinogen & Factor VII =

Shortening of the PT & PTT (faster clotting times)

The increase in coagulation (hypercoaguable state) may be a protective mechanism to deal with the acute hemorrhage at delivery

Changes in hemoglobin concentration

Decreases for the first three postpartum days

Rises rapidly for the next three days

Gradually returns to prepregnant levels at 6 weeks postpartum

d/t pronounced diuresis = Hgb becomes concentrated

changes that take place in coagulation during pregnancy:

During the first 3-5 postpartum days fibrinogen and platelet counts begin to rise, concurrent with an increased incidence of thrombotic events

(1st few days after birth are dangerous for the mom d/t high risk for thrombosis)

Coags return to normal at 2 weeks

How much blood is lost during vaginal delivery?

During C/S?

vaginal: 600ml

C/S: 1000ml

At delivery, maternal venous capacitance is reduced by the volume of the ______ (____ml)

This volume is ____ replaced or ____ in the maternal blood loss estimate.

At delivery, maternal venous capacitance is reduced by the volume of the intervillous space (>500ml)

This volume is NOT replaced or counted in the maternal blood loss estimate.

How much does the colloid osmotic pressure decrease in pregnancy?

What is the decrease in colloidal osmotic pressure due to? (2)

Colloid osmotic pressure decreases by about 5mm Hg during pregnancy

Reduction in albumin (4.5 to 3.3 g/dl)

Reduction in total protein (7.8 to 7g/dl)

How much does MV increase w/ pregnancy

What causes increased MV?

45%

Progesterone sensitizes the respiratory center to CO2 

PaCO2 falls to 30mmHg by 12th week

also...Increased CO2 production

It doesn't

increase in MV is solely d/t increased TV

Cause there's a baby in there!!!

Gravid uterus and decreased thoracic cage movement

FRC/CC Ratio

 CC>> FRC = 

CC>FRC = 

CC<FRC = 

CC in the amount of air that has to stay in the lungs to keep ____ _____ ____.

CC>> FRC = atelectasis

CC>FRC = Low VA/Q

CC<FRC = Normal

CC in the amount of air that has to stay in the lungs to keep small airways open.

**How does the FRC change?

What about when pregnant pt is supine?

Decreases by 20%

Decreases by 70%

rapid oxygen desaturation

**PRE-OXYGENATION IS PARAMOUNT PRIOR TO INDUCTION**

Hyperventilation may itself reduce uterine blood flow

Mechanism unclear

Effective pain relief

Labor epidural

What are factors that compound airway managment?

Should you use an LMA or nasal airway with these pts?

1. Capillary engorgement of the mucosa

2. Edema of the Oropharynx, Larynx, & Trachea

3. Manipulation of the airway (suctioning, airway insertion,  intubation - avoid nasal instrumentation if possible)

NO - only use if really needed and BE GENTLE!

Unaltered

Slowed during labor

What causes slowed esophageal peristalsis & intestinal motility during pregancy?

When does this occur?

Increased progesterone levels

as progesterone levels rise (so early in preg)

Displaces the intrabdominal segment of the esophagus into the thorax

Reduces tone in the LEHPZ which normally prevents reflux

Intragastric pressure elevated in 3rd trimester

IM and IV opioids

Intrathecal opioids

Bolus epidural opioids (100mcg Fentanyl)

Gastric empyting returns to normal about ___ after delivery?

Dr Anderson considers a ___ trimester pregnant lady to be full stomach until __ after birth.

18 hours after delivery

Dr Anderson considers a1st trimester pregnant lady to be full stomach until 2-3 days after birth.

What causes the decreased BUN and Creatnine seen in pregancy?

Increased cardiac output + incr. plasma volume

↓

Increased renal plasma flow & incr. GFR by 50%

Common for liver function tests increase to _______ in pregnancy

...usually not an issue.

What changes are seen r/t the gall bladder?

What happens to bile and what can this cause?

Gallbladder volumes markedly increase 

 the rate of emptying slows

Bile becomes concentrated predisposing the pt to gallstones

Plasma cholinesterase concentration_______25% during the ____ trimester and remains at that level for up to_______postpartum

Does this cause a clinically relevant change in duration of sux?

Plasma cholinesterase concentration decreases 25% during the first trimester and remains at that level for up to 6 weeks postpartum

no

How does MAC change in pregnancy?

When does it return to normal?

MAC reduced about 30% from early pregnancy

returning to normal about 3 days postpartum

Increased progesterone has a sedative effect and reduces MAC in animal studies

Increased CNS serotonergic activity

Increased endorphin levels during pregnancy

*if give enough progesterone can cause LOC

What brings about pregnancy induced analgesia?

How can this effect be ablated?

Increased pain threshold in late pregnancy & labor d/t elevated levels of endorphins and enkephalins in plasma and CSF

Effect ablated by intrathecal or systemic opioid antagonist (narcan)

*Dependence on ____ nervous system for maintenance of hemodynamic stability increases progressively during pregnancy and reaches a peak at term/primarily on venous capacitance of _______.

What do we have to watch out for?

What can attenuate this?

Dependence on sympathetic nervous system for maintenance of hemodynamic stability increases progressively during pregnancy and reaches a peak at term/primarily on venous capacitance of lower extremities

*SNS is responsible for venous tone

Beware of sympathectomy!!!

Prehydration - more than for a reg patient

Pregnant women display a _________response to a carbohydrate load.

So why don't we see hypoglycemia?

We actually see ____ blood sugar following a carbohydrate load.

Pregnant women display a hyperinsulinemic response to a carbohydrate load.

The hyperinsulinemic response is more than compensated for by reduced tissue sensitivity to insulin

Increased blood sugar following a carbohydrate load

During late pregancy fasting blood glucose is decreased. 

What causes this decrease?

What changes are seen in the leukocyte count?

Polymorphonuclear leukocyte function is impaired. 

This explains what 2 things?

Increased incidence of infection

Decreased symptoms of autoimmune disease, such as rheumatoid arthritis

What general change is seen in the curvature of the spine?

This can lead to a numbness of the lateral thigh called __________ which is caused by excessive retraction on the ______ nerve.

Exaggerated lumbar lordosis

meralgia paresthetica

lateral femoral cutaneous nerve

Why does the incidence in carpel tunnel syndrome increase?

Due to changes in nature of connective tissue

ie. Absorption of more fluid (d/t decr colloid osmotic pressure)

An induction dose of sodium thiopental should be ____ by 35%....per notes, but Dr. Anderson says you shouldn't do that b/c you really need to make sure pt is out since you will not be giving them any narcotics or benzos.

How does the elimination half-life of IV induction agents change?

Why?

Which IV agent shows no significant change in elimination half life?

Elimination half-life increased from 11.5 to 26.1 hrs

due to increased volume of distribution

propofol

*note Ron says this is all insignificant

There is a 25% ______ in plasma cholinesterase activity

So why do we see faster recovery with succinylcholine?

What happens after delivery?

decrease plasma cholinesterase activity

Faster recovery is explained by increased volume of distribution

After delivery the decrease in plasma cholinesterase activity and plasma volume alters succinylcholine pharmacokinetics

Do we use a defasciculating dose of NDMR?

 Which 2 nondepolarizers are altered in their pharmacokinetics? How are they altered? Name one that is unaltered.

Does this matter?

NO b/c it will slow onset of Sucs and we want really fast onset to quickly secure airway also myalgias are rare in pregnant pts per lec (this will not be on test)

Vecuronium & Rocuronium - Enhanced sensitivity

 Atracurium Unaltered

No b/c you will be giving small doses and titrating based on PNS per lec

40%

decrease in femoral arterial pressure

d/t Aortic compression in the supine position

Uterine Blood Flow

Non-pregnant?

Pregant?

Non-pregnant - 50-100ml/min

Pregnant - 700-900ml/min

(Uterine art. press - uterine ven. press) 

÷

Uterine vascular resistance

↓uterine arterial pressure d/t systemic hypotension

↑ uterine venous pressure (can occur w/ caval compression)

↑ uterine vascular resistance

Growth of new blood vessels

Vasodilation

Altered response to vasoconstrictors (Angiotensin II, alpha adrenergic agonists)

Vasoactive substances

Increased synthesis of vasodilators(Prostaglandins, NO)

Steroid hormones

shear stress 

AVISs

How does Angiotensin II levels change during pregnancy?

What happens to the vasocontriction response?

2-3 fold increase in blood concentration

Vasoconstriction response is attenuated systemically (not as attenuated in preclampsia)

In pregnancy, uterine vasculature is much ____ responsive to angiotensin II than the systemic vasculature.

What are 2 mechanisms of this?

uterine vasculature is much less responsive to angiotensin II than systemic vasculature

1. Angiotensin II receptor alteration

(AT1 = 10% AT2= 90% in uterus and AT2 receptors dont mediate vasoconstriction...mostly AT1 in systemic vasculature p 41)

2. Local antagonism of effects of angiotensin II

(by Prostacyclin and Nitric Oxide)

How is the systemic sensitivity to alpha-adrenergic agonists changed during pregnancy?

How does the uterine vasculature compare to the sytemic vasculature regarding responsiveness to alpha-adrenergic agonists?

Decreased sensitivity to alpha adrenergic agonists systemically

But uterine vasculature is more responsive than the systemic vasculature

What 2 things will cause potential impairment of uterine blood flow d/t increased sensitivity to alpha agonists?

T/F: It can be said that in times of stress uterine BF will not be maintained preferentially above essential maternal perfusion

Release of endogenous catecholamines due to stress, hemorrhage, etc 

Exogenous administration of vasocontrictors for management of hypotension

True p 41

How is prostaglandin production changed in pregnancy?

Which one in particular?

Increased production & circulation

Particularly Prostacyclin (PGI2) (vasodilation)

NO is produced in _______, stimulates ______, increasing ____, with subsequent _________

What changes occur with Nitric oxide during pregancy?

T/F if inhibit NO synthase, the mother will have HTN & fetal growth will be inhibited d/t decreased uterine BF?

Produced in vascular endothelium, stimulates guanylate cyclase, increasing cGMP, with subsequent vasodilation

Increased NO production in uterine vs systemic vasculature during pregnancy

True

How does Estrogen affect uterine blood flow?

What mediates this?

Increases uterine blood flow

Appears to be mediated by vasodilation produced by increased nitric oxide → guanylate cyclase → cGMP production

How do ANP and BNP affect uterine blood flow?

In which pts can an ANP infusion be useful?

What does it do?

Shown to attenuate the vasoconstrictive response to angiotensin II

ANP infusion useful in preeclampsia to decrease BP and increase uterine bloood flow

Decreased in uterine but not systemic arteries in (pregnant ewes)

*normally mediates alpha adrenergic receptors in smooth muscle of uterus....etc

What is the likely mechanism of ephedrine's protection of uterine perfusion?

*In pregnancy the uterine arteries are _____ & have increased endothelial cell ____ and the endothelial cells have an _____ ability to synthesize NO.

Enhanced release of nitric oxide from uterine artery endothelium

(vasoconstriction occurs systemically with ephedrine but dilation occurs in the uterus - see picture on slide 56)

*In pregnancy the uterine arteries are dilated & have increased endothelial cell mass and the endothelial cells have an increased ability to synthesize NO

Why is ephedrine usually preferred? (3)

Does ephedrine cross the placenta?

Apparent protection of uterine blood flow

History of safety

Ease of use

yes

Some studies have shown higher cord pH following treatment with phenylephrine or ephedrine?

When would phenylephrine be an appropriate choice?

 phenylephrine

In a pt in whom tachycardia would be detrimental (higher HR w/ ephedrine)

 Despite preserved uterine blood flow, ephedrine crosses the placenta increasing fetal ____.

This might be the cause of ____ cord pH w/ephedrine than w/ phenylephrine

 ephedrine crosses the placenta increasing fetal heart rate

This might be the cause of lower cord pH w/ ephedrine

Simple diffusion (Fick Principle)

Active transport

Pinocytosis

Molecular weight

Maternal drug concentration

Maternal and fetal pH

pKa of drug (only unionized drugs cross placenta)

Protein binding

Lipid solubility

triple M, double P, single L

Inhalational agents

N2O

IV induction agents

Diazepam>Midazolam

Opioids

Local Anesthetics

Atropine

Antihypertensives

Ephedrine

Cocaine

Warfarin

 Glycopyrrolate

LMWH

Anticholinesterases

Muscle relaxants

 (GLAM)

Nope, that's just not true.

Not associated with fetal distress.

What are late decelerations likely due to?

Maintained beat to beat _____ is reassuring

Uteroplacental insufficiency

variability

What are the most common decelerations?

Variable decelerations

 Variable decelerations

Variable in what 3 ways?

What causes variable decelerations?

T/F: Usually well tolerated in healthy fetus

 Variable in magnitude, duration, & time of onset

Umbilical cord compression

True

What is the range for normal heart rate variability?

What does maintained beat to bet variability imply?

5-20 bpm

Maintained beat to beat variability implies fetal well being

Loss of beat to beat variability is associated with ____.

What can this be due to?

Fetal distress

due to

hypoxemia

acidosis

CNS damage

 Barbiturates

Local anesthetics

Opioids

Benzodiazipines

Anticholinergics

Prematurity

Fetal sleep cycles 

(BLOB APL)