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49 Cards in this Set
- Front
- Back
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What are the most common morbid items encountered in obstetrics?
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Severe hemorrhage and severe preeclampsia
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Key point about NPO and obstetrics
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-regardless of the last oral intake, all OB patients are considered to be a full stomach and at risk of aspiration
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Key point about managing labor pain
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-nearly all PO opioids and sedatives rapidly cross the placenta and affect the baby, so regional techniques for pain control are preferred
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Key point about drug mixtures in the epidural
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-using a mixture of local and opioid for lumbar epidural anesthesia during labor reduces drug requirments compared to using either alone
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Key point about level of block needed for the stages of labor
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-the first stage of labor requires block of T10-L1, the 2nd stage requires T10-S4
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What is the most versatile and commonly used technique for labor?
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-continuous lumbar epidural anesthesia since it can be used for pain relief in the first stage of labor, and then also for analgesia/anesthesia for vaginal or c-section
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Key point about lumbar epidurals and the progression of labor
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-when dilute mixes of local and an opioid are used epidural analgesia has little if any effect on the progress of labor
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Key concept about epidural catheter placement
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-even if aspiration is negative for blood or CSF, the catheter can still be intravascular or intrathecal
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Key point about the most common side effect of regional anesthesia and it's treatment
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-hypotension is the most common side effect
-it must be treated aggressively with ephedrine and fluids to prevent fetal compromise |
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Key point about CSE
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-may especially benefit patients with severe pain early in labor, and those who get analgesia/anesthesia just prior to delivery
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Key point about anesthesia for c-section
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-spinal or epidural is preferred to general because it's associated with lower maternal mortality
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Key point about spinal vs. epidural for c-sections
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-spinal is easier to perform and results in more rapid and intense neural blockade than epidural
-epidural allows greater control over sensory level and causes a slower drop in arterial BP |
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Key point about preventing systemic local toxicity
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-is best avoided by slowly giving dilute solutions for labor pain, and fractioning the total dose for an epidural into 5ml increments
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Key point about the life of the mother vs. the life of the fetus in a difficult intubation during c-section
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-if doing general for c-section and intubation fails, the life of the mother takes priority over delivery of the fetus
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Key point about the most common cause of severe morbidity of OB and it's causes
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-maternal hemorrhage is one of the most common severe morbidities
-causes include placenta previa, abruptio placentas, and uterine rupture |
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What 3 syndromes are included in pregnancy induced hypertension?
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1. Preeclampsia
2. Eclampsia 3. HELLP syndrome |
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What are the common causes of postpartum hemorrhage?
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-uterine atony
-retained placenta -obstetric lacerations -uterine inversion -use of tocolytics prior to delivery |
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Key point about the most common cause of neonatal depression and preventing it
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-the most common cause during labor is intrauterine asphyxia
-fetal monitoring throughout labor is good to identify at risk babies, to detect fetal distress, and to evaluate the effect of acute interventions |
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What are the guidelines by the American College of Obstetricians and Gynecologists and the ASA about anesthesia and obstetrics?
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-an anesthesia service by readily available continuously
-a c-section be started within 30 min of recognition of its need -also, high-risk pts, like those undergoing VBAC (trial of vaginal birth after previous c-section) might need immediate availability of anesthesia services |
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General point about surgical risk of obstetric patients
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-although most women of childbearing age are healthy and good surgical candidates, pregnancy, certain maternal and fetal factors, and preexisting medical conditions significantly increase surgical and obstetric risks
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How is pregnancy relates mortality calculated?
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As pregnancy-related deaths/ number of live births
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Pregnancy-related mortality
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-has decreased nearly 100fold since 1900, though hasn't fallen since 1982 (in fact may have risen due to better reporting)
-in the US was 11.8 deaths per 100,000 live births from 1991-1999, and is similar in Canada and the UK |
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In which women is overall mortality higher?
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-women >35 yo
-black patients -without prenatal care |
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Leading causes of death for live births
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-PE (21%)
-pregnancy-induced hypertension (19%) -other medical conditions (19%) -infection 14% -cardiomyopathy 11% -CVA 6% -hemorrhage 5% -anesthesia 2% -unknown 1% |
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Major causes of death associated with stillbirth
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-hemorrhage 21%
-pregnancy-induced hypertension 20% -sepsis 19% |
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Additional important causes of death based on the clearer Canadian data
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-add amniotic fluid embolism and intracranial hemorrhage to PE and preeclampsia/pregnancy induced hypertension
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Risk factors for severe obstetric morbidity
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-age >34
-nonwhite -multiple pregnancy -history of hypertension -previous postpartum hemorrhage -emergency c-section |
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Most common causes of severe obstetric morbidity
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-by far the highest are severe hemorrhage and severe preeclampsia
-trailing are HELLP syndrome, severe sepsis, eclampsia, and uterine rupture |
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What are all the things that cause pain during labor?
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-contraction of the myometrium against the resistance of the cervix
-progressive dilation of the cervix and lower uterine segment -stretching and compression of the pelvic and perineal structures |
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What is pain during the 1st stage of labor due to?
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-mostly visceral pain due to uterine contractions and clerical dilation
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Dermatomes involved in the first stage of labor pain
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-initially is confined to T11-12 during the latent phase, eventually involves T10-L1 in the active phase
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Rout of visceral afferent fibers responsible for labor pain
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-travel with sympathetic nerve fibers first to the uterine and cervical plexuses, then through the hypogastric and aortic plexuses before entering the spinal cord with the T10-L1 nerve roots
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Location of labor pain
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-is primarily in the lower abdomen, but can be increasingly referred to the limbo sacral area, the gluteal region, and thighs as labor progresses
-intensity of the pain increases also with progressing clerical dilation and increasing frequency and intensity of contractions |
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Which women have worse pain during the 1st stage of labor?
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-nulliparous women
-those with a history of dysmenorrhea |
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What do studies show about women who have worse pain during the latent stage of labor?
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-they have longer labors and are more likely to have c-sections
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What does the onset of perineal pain at the end of the first stage mean?
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-the beginning of fetal descent and the 2nd stage
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What does this bring in terms of pain?
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-the pain intensifies as there is stretching and compression of pelvic and perineal structures
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What's the sensory innervation to the perineum, and what does this mean about pain during the second stage of labor?
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-sensory to the perineum is by the pudendal nerve (S2-4)
-therefore pain during the second stage involves the T10-S4 dermatomes |
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What do studies show at the intensity of 2nd stage of laor pain?
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Tat the more rapid fetal descent in multiparous women is associated with more intense pain than the more gradual descent in nulliparous women
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Parenteral opioids and sedatives during labor
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-nearly all cross the placenta and can effect the fetus
-concern for the fetus limits their use to early stages of labor, or when regional can't be used |
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How will CNS depressin manifest in the neonate and fetus?
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-in the fetus by loss of beat-to-beat variability in the heart rate and decreased fetal movements (due to sedation) (this all complicates the OB's ability to evaluate fetal well-being
-in the neonate, by prolonged time to sustain respirations, respiratory acidosis, an abnormal neurobehavioral exam |
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What factors affect how depressed the baby will be?
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-the specific agent used
-the dose -the time between the drug and delivery -fetal maturity (premature neonates are the most sensitive) |
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In addition to maternal respiratory depression, what else can opioids do?
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-they can cause maternal nausea/vomiting, and delayed gastric emptying
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Way technique is advocated by some as a way to reduce total opioid requirements?
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-PCAs early in labor
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What's the most commonly used opioid?
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Meperidine
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Meperidine use in labor
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-dose is 10-25 mg IV, or 25-50 mg IM, usually up to a total of 100mg
-since the max maternal and fetal respiratory depression occurs at 10-20 min after IV and 1-3hrs after IM, it's usually given early when delivery isn't expected for 4hrs |
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Besides meperidine, which other opiate is used in labor?
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Fentanyl
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Fentanyl use in labor
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-25-100 mcg doses have a 3-10 min onset, and last about 60 min, and lasts longer after multiple doses
-low doses are shown to have little or no neonatal respiratory depression or affect on APGAR score |
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What is the important point to make about fentanyl in labor though?
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The maternal respiratory depression outlasts the analgesia
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