Obstetrics and Gynecology

CHAPTER 30
Obstetrics and Gynecology


Leon Plowright and Christine Chen


Test Taking Tip


Remember to review the management of tubo-ovarian abscesses and the physiologic changes of the pregnant patient during each of the trimesters.


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FIGURE 30-1. The muscles and vasculature of the pelvis. (Reproduced from Brunicardi FC, Andersen DK, Billiar TR, et al. Schwartz’s Principles of Surgery. 9th ed. www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


ANATOMY


What are the branches of the internal iliac artery (hypogastric)?


Posterior division: Iliolumbar, lateral sacral, superior gluteal Anterior division: Obturator, internal pudendal, inferior gluteal, umbilical, middle vesicle, inferior vesicle, middle hemorrhoidal, uterine, vaginal


Arterial supply to the uterus:


Uterine artery from the hypogastric and ovarian arteries directly from the aorta


Right ovarian vein originates from:


Inferior vena cava


Left ovarian vein originates from:


Left renal vein


Vaginal arterial supply


Upper: cervical branch of the uterine artery


Middle: inferior vesical


Lower: internal pudendal and middle hemorrhoidal


The major arterial supply to the cervix is located:


In the lateral cervical walls at the 3 and 9 o’clock positions


The external pudendal artery supply:


The rectum, labia, clitoris, perineum


Artery that supplies the round ligament:


Sampson


Inferior epigastric artery and vein originates from:


External iliac artery and external iliac vein, respectively


Levator ani complex:


Iliococcygeus, pubococcygeus, puborectalis


Boundaries of the femoral triangle:


Sartorius, adductor longus muscle, and inguinal ligament


Floor of the femoral triangle is formed by:


Iliopsoas, pectineus, and adductor longus


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FIGURE 30-2. The avascular spaces of the female pelvis. (Reproduced from Brunicardi FC, Andersen DK, Billiar TR, et al. Schwartz’s Principles of Surgery. 9th ed. www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


Space of Retzius:


The area between the bladder and the symphysis pubis, bounded laterally by the obliterated hypogastric arteries


Cul-de-sac of Douglas:


Also known as the rectouterine pouch or fold and is located anterior to the rectum, separating the uterus from the large intestine


Boundaries of the paravesical space:


Anterior: pubic symphysis


Posterior: cardinal ligament


Medial: superior vesical artery


Lateral: obturator internus muscle


Boundaries of the pararectal space:


Anterior: cardinal ligament


Posterior: sacrum


Medial: rectum


Lateral: iliac vessels


Anatomic relationship between the uterine artery and the ureter:


At approximately 2 cm from the cervix, the uterine artery crosses above and in front of the ureter.


Support of the uterus:


The cardinal and uterosacral ligaments


Vaginal lymphatics:


Upper third: Iliac


Middle third: hypogastric


Lower third: inguinal


Aorta lies at this spinal level:


L4


Innervation to the uterus:


Hypogastric plexus by sympathetic merging at Frankenhauser plexus (uterovaginal plexus) Pain sensory to T11 to 12


Sensory innervation of the vagina:


Pudendal nerve (S2–S4)


Obturator nerve:


Sensory and motor to the medial thigh


Sciatic nerve:


L4 to S2; passing through the greater sciatic foramen to supplying the muscles of lateral leg and foot


PHYSIOLOGY


Increases in pregnancy:


GFR by 50%: 90 mL/min prepregnancy versus 125 mL/min pregnancy


Total T4


Total T3


PTH


Prolactin


Plasma fibrinogen: 300 mg/dL prepregnancy versus 600 mg/dL pregnancy


ESR


TBG: thyroxine-binding globulin


Cholesterol


Heart rate: Increased 10 to 15 bpm


Cardiac output: 1.5 mL/min more than prepregnant average


Prostacyclin


Thromboxane


Plasma volume


Red cell volume


Alkaline phoshatase


Human placental lactogen


Progesterone


Estradiol


Decreases in pregnancy:


Total serum calcium


Albumin (decrease by 30%)


BUN and creatinine: due to increase in GFR


Hgb and Hct


Factor XI


Factor XIII


TSH


Systemic vascular resistance


pCO2: 35 to 40 mm Hg prepregnant to 28 to 30 mm Hg pregnant


Respiratory volume


Antithrombin III (anti-factor Xa)


Anticoagulant protein S


Cross the placenta:


Propylthiouracil, TRH, iodine, magnesium sulfate, IgG, propanolol, warfarin


Does not cross the placenta:


T3, T4, TSH, insulin, glucagon, heparin, prednisone


hCG peaks at:


8 to 10 weeks gestation


Average weight gained in pregnancy:


25 lb


Average weight and volume of non-pregnant uterus:


40 to 70 g and 10 mL


Average weight and volume of pregnant uterus:


1100 to 1200 g and 5000 mL


What supports pregnancy during the first 14 weeks of pregnancy prior to the development of the placenta?


The corpus luteum, which secretes progesterone


Gestational age at which the uterus rises out of the pelvis:


12 weeks gestation


In late pregnancy blood flow rate to the uterus:


450 to 650 mL/min


Percentage of uterine blood flow direct to the placenta at term:


80% to 90%


Pulmonary function in pregnancy:


Increase: Tidal volume, inspiratory capacity, minute ventilation, minute oxygen uptake


Decrease: Functional residual capacity (by 15%), residual volume, expiratory reserve volume


Unchanged: Maximum breathing capacity, forced expiratory volume (FEV1)


Physiologic hydronephrosis of pregnancy resolve in:


12 to 16 weeks postpartum


Gastric acid production and gastric emptying:


Increased and decreased, respectively, in pregnancy


Two GI disorders in third trimester pregnancy:


Acute fatty liver of pregnancy and cholestasis of pregnancy


OBSTETRICAL CONDITIONS AND COMPLICATIONS


Incidence of hypertensive disease in pregnancy:


12% to 22%


New onset hypertension and proteinuria after 20 weeks gestation in a previously normotensive woman:


Preeclampsia


Criteria for diagnosis of preeclampsia:


Mild: BP 140/90, 6 hours apart plus at least 1+ protein on urine dip or >300 mg of protein on 24-hour urine


Severe: BP 160/110 6 hours apart plus at least 3+ protein on urine dip or 5000 mg of protein on 24-hour urine protein


New-onset hypertension without proteinuria after 20 weeks gestation in a previously normotensive woman:


Gestational hypertension


New-onset grand mal seizure in woman with preeclampsia:


Eclampsia


Treatment of preecalmpsia:


Magnesium sulfate for seizure prophylaxis, labetalol and hydralazine for BP control and expedient delivery


HELLP syndrome is characterized by:

Aug 13, 2019 | Posted by in ABDOMINAL MEDICINE | Comments Off on Obstetrics and Gynecology
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