Medical brain notes 42

  CLASSIFICATION   Various classifications of hypertensive disorders in preg-nancy have been proposed. Box 16.1 presents a commonly used classification. Because hypertensive disorders in preg-nancy represent a spectrum of disease, classification systems should be used as a guide only   Chronic Hypertension Chronic hypertension  is defined as hypertension present beforethe 20th week of pregnancy or hypertension present before preg-nancy.  The categories of hypertension in pregnancy andthe blood pressure (BP) criteria used to define each are as follows:   ·              Mild hypertension: Systolic pressure of  >= 140–180 mm Hg or diastolic pressure of  >= 90–100 mm Hg or both ·              Severe hypertension: Systolic pressure of  >= 180 mm Hg or diastolic pressure of  >= 100 mm Hg   A major risk with c...

  PATHOPHYSIOLOGY   Hypertension in pregnancy affects the mother and new-born to varying degrees. Given the characteristic multi-system effects, it is clear that several pathophysiologic mechanisms are involved (Fig. 16.1).  The predominant patho-physiologic finding in preeclampsia and gestational hypertension is  maternal vasospasm. Several potential causes for mater-nal vasospasm have been postulated:   ·       Vascular changes:  Instead of noting the physiologictrophoblast-mediated vascular changes in the uterine vessels (decreased musculature in the spiral arterioles leads to the development of a low-resistance, low-pressure, high-flow system), inadequate maternal vas-cular response is seen in cases of preeclampsia and/or intrauterine fetal growth restriction. Endothelial dam-age is also noted within the vessels.   ·       Hemostatic changes:  Increased platelet activationwith increased consump...

  EVALUATION   The history and physical examination are directed toward detection of pregnancy-associated hypertensive disease and its signs and symptoms. A review of current obstetric records, if available, is especially helpful to ascertain changes or progression in findings.  Visual disturbances, es-pecially scotomata, or unusually severe or persistent headaches are indicative of vasospasm.  Right-upper-quadrant pain mayindicate liver involvement, presumably involving disten-tion of the liver capsule. Any history of loss of conscious-ness or seizures, even in the patient with a known seizure disorder, may be significant.   The position of the patient influences blood pressure.  It islowest with the patient lying in the lateral position, high-est when the patient is standing, and at an intermediate level when she is sitting. The choice of the correct-size blood pressure cuff also influences blood pressure readings, with falsely high measurements noted whe...

  MANAGEMENT   The goal of management of hypertension in pregnancy is to bal-ance the management of both fetus and mother and to optimize the outcome for each.  Maternal blood pressure should be mon-itored and the mother should be observed for the sequelae of the hypertensive disease. Intervention for maternal indi-cations should occur when the risk of permanent disability or death for the mother without intervention outweighs the risks to the fetus caused by intervention. For the fetus, there should be regular evaluation of fetal well-being and fetal growth, with intervention becoming necessary if the intra-uterine environment provides more risks to the fetus than delivery with subsequent care in the newborn nursery.   Chronic Hypertension   The management of patients with chronic hypertension in preg-nancy involves closely monitoring maternal blood pressure and watching for the superimposition of preeclampsia or eclampsia, and following the fetus for appropria...