"Antihypertensive" management of hypertension during pregnancy, how to choose different classes of antihypertensive drugs?
Gestational hypertensive disorder is a common obstetric complication, the main clinical manifestations are high blood pressure, edema, proteinuria, can be accompanied by systemic multi-organ damage or failure, classification includes preeclampsia-eclampsia, chronic hypertension, chronic hypertension complicated by preeclampsia and gestational hypertension. In the past, antispasmodic treatment was prioritized to prevent eclamptic tics, but effective blood pressure control is now considered an important factor in preventing serious complications such as eclampsia, cardiovascular and cerebrovascular accidents, and placental abruption.
Considering fetal safety and placental circulation, what antihypertensive drugs to choose, when to start antihypertensive drugs, and the goals to be achieved are all clinically important questions.
01 The diagnosis and evaluation of hypertension during pregnancy should be correct: pregnant women should rest quietly for at least 5 minutes; Sitting or lying position, relaxed limbs; The cuff is the right size; right upper extremity blood pressure; The cuff should be at the same level as the heart.
1.Definition of gestational hypertension: Hypertension: SBP 140mmHg and/or DBP 90mmHg measured at least 2 times in the same arm.
If the blood pressure is elevated for the first time, the blood pressure should be remeasured at an interval of 4 hours or more, such as SBP 140mmHg and/or DBP 90mmHg for both measurements; Severe hypertension: Diagnosis is made in patients with SBP 160 mmHg and/or DBP 110 mmHg, repeated measurements at intervals of several minutes;
Severe hypertension: SBP 160 mmHg and/or DBP 110 mmHg;
Hypertensive emergency: severe hypertension such as acute onset that lasts for 15 minutes;
White coat hypertension: high office blood pressure (140-90 mmHg) compared to 130-80 mmHg at home;
Normal 24-hour ambulatory blood pressure definition:
The average throughout the day is 130 80mmHg, the daytime average is 135 85mmHg, and the night average is 120 70mmHg.
2.Classification of hypertensive disorders in pregnancy: gestational hypertension: first onset of hypertension after 20 weeks of gestation, SBP 140 mmHg and/or DBP 90 mmHg, negative urine protein test;
Severe gestational hypertension:
SBP 160mmHg and/or DBP 110mmHg;
Preeclampsia-Eclampsia: Hypertension after 20 weeks of gestation, accompanied by any of the following:
Urine protein quantification 03 g for 24 hours, or urine protein Creatinine ratio 03, or random urine protein (+
There is no urine protein but one of the following organs or systems is involved: abnormal changes in important organs such as heart, lungs, liver, kidneys, or blood system, digestive system, nervous system, placenta-fetal involvement, etc.;
Severe preeclampsia: persistently elevated blood pressure and/or urine protein levels, or organ function involvement or placental development in pregnant women Fetal complications:
1) Uncontrollable continuous elevation of blood pressure: systolic blood pressure 160mmHg and/or diastolic blood pressure 110mmHg;
2) persistent headache, visual disturbances or other central nervous system abnormalities;
3) persistent epigastric pain and manifestations of hepatic subcapsular hematoma or hepatic rupture;
4) Abnormal aminotransferase levels: elevated levels of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) in the blood; (5) Impaired renal function: urine protein quantification" 20 g/24 h；oliguria (24-hour urine output < 400 ml, or urine output per hour <17 ml), or serum creatinine level 106 mol l;
6) hypoproteinemia with ascites, pleural effusion, or pericardial effusion;
7) Hematologic abnormalities: platelet count is continuously decreased and lower than 100 109 L; microvascular hemolysis with anemia, elevated serum lactate dehydrogenase (LDH) levels, or jaundice;
8) heart failure;
9) pulmonary edema;
10) Fetal growth restriction or oligohydramnios, fetal death in utero, placental abruption, etc. Eclampsia: tonic tics that occur on the basis of preeclampsia that cannot be explained by other causes; Chronic hypertension in pregnancy: Pregnant women with prior hypertension or systolic blood pressure of 140 mmHg and/or diastolic blood pressure of 90 mmHg before 20 weeks' gestation, without significant exacerbations or acute severe hypertension during pregnancy;
or high blood pressure first detected after 20 weeks of gestation but persists beyond 12 weeks postpartum; Chronic hypertension with preeclampsia Pregnant women with chronic hypertension have no proteinuria before 20 weeks of gestation and proteinuria after 20 weeks of gestation; There is proteinuria, and the amount of protein in the urine increases significantly after 20 weeks of pregnancy;
Any one of the above manifestations of severe preeclampsia, such as a further increase in blood pressure. Others require dynamic monitoring and early identification: "white coat hypertension", transient or transient hypertension, single proteinuria, fetal growth restriction, thrombocytopenia, neurological symptoms, abnormal laboratory indicators.
02 Classification of antihypertensive drugs and selection of drugs during pregnancy1Classification of antihypertensive drugs:
1) Diuretics (thiazides).
2) Adrenergic blockers receptor (zorazinoids) receptors (lol).
3) Calcium antagonists (dipine).
4) ACE inhibitors (pril).
5) Angiotensin II receptor antagonists (sartans).
6) Sympathetic inhibitor: methyldopa.
2.It should be safe & effective during pregnancy.
Pharmacologic diuretics, adrenergic blockers, and angiotensin-converting enzyme inhibitor II receptor antagonists should be avoided during pregnancy, which have varying degrees of effect on the fetus.
Diuretics: can reduce maternal blood volume, often causing adverse perinatal infants; High doses can cause fetal thrombocytopenia, interfere with fetal coagulation mechanisms, and have a risk of bleeding. Adrenergic blockers: Receptors (e.g., prazosin) should be used with caution due to less clinical experience. Receptor class (representative drug propranolol) is associated with intrauterine hypoxia, low birth weight and increased perinatal mortality, and should not be used for gestational hypertension**.
ACE inhibitor II receptor antagonists: fetal exposure to ACE inhibitors during the first 3 months of pregnancy increases the risk of severe congenital malformations.
Drugs can be used during pregnancy: labetalol, methyldopa: are commonly used antihypertensive drugs during pregnancy, safe.
Labetalol: is a new third-generation receptor antagonist and 1-receptor antagonist. The antihypertensive effect of labetalol can dilate vasodilates by antagonizing 1 receptors and activating 2 receptors to relax vascular smooth muscle, while cardiac output is not significantly reduced, and maternal heart rate and placental blood perfusion are not significantly changed.
There is no significant relationship between use during pregnancy and teratogenicity.
Nifedipine, nimodipine: It is a calcium antagonist, ** has obvious efficacy in gestational hypertension, and it is easy and safe to use. There are no experimental data to suggest that these drugs have teratogenic, fetal blood pressure, or alter uteroplacental blood flow.
Hydralazine: It can directly dilate peripheral blood vessels, mainly dilating arterioles, has a strong antihypertensive effect, reduces peripheral total resistance and lowers blood pressure, can improve the blood flow of the kidney, uterus and brain, and has no adverse effects on the fetus. Table 1: Recommended selection of antihypertensive drugs during pregnancy in different countries**.
3.Timing, goals, and principles of blood pressure lowering should be evaluated before blood pressure reduction: classification of hypertensive disorders during pregnancy; severity and duration of hypertension; whether there is organ damage; gestational age of onset; Past ** conditions.
Antihypertensive purpose: to prevent the occurrence of severe preeclampsia and eclampsia, lowering blood pressure can halve the risk of developing severe hypertension, prevent cardiovascular and cerebrovascular accidents, prevent placental abruption, and improve maternal and infant outcomes.
Buck principle: stable; Not less than 130 80mmHg; Emergency hypotensive: severe hypertension, organ damage such as acute left ventricular failure; The range of blood pressure reduction should not be too large, 10%-25% of the average arterial pressure (MAP) is appropriate, and it should reach stability in 24-48 hours; Individualized.
03Step-down hierarchical management.
1.Gestational hypertension: diet and lifestyle; Outpatient**; Lowering blood pressure as appropriate; 2.Severe gestational hypertension, preeclampsia, severe preeclampsia hospitalization: pregnant women with SBP 160mmHg or DBP 110mmHg are emergency;
Magnesium sulfate: used for the prevention of eclampsia in severe preeclampsia, before the onset of severe preeclampsia, not as a antihypertensive drug;
Sedation: when magnesium sulfate is ineffective or contraindicated;
Diuresis: patients with preeclampsia have hypovolemia, so it is best to avoid diuresis**, and low-dose furosemide may be considered if generalized edema, pulmonary edema, cerebral edema, renal insufficiency, heart failure, or oliguria are present;
promote the maturation of the fetal lungs;
Choose when and how to terminate your pregnancy. 3.Eclampsia: magnesium sulfate** convulsions;
Reduces intracranial pressure; Actively control blood pressure below 160mmHg and 110mmHg; correction of acidosis; Termination of pregnancy.
4.Pregnant patients with chronic hypertension: dynamic monitoring of blood pressure changes, mainly antihypertensive**; Prevent the occurrence of preeclampsia. 5.Chronic hypertension with preeclampsia: Chronic hypertension and preeclampsia**; Patients with clinical signs of severe preeclampsia should be treated as severe preeclampsia.
04 Emergency blood pressure reduction method.
1.For those who have not used antihypertensive drugs, oral administration is preferred, blood pressure is monitored every 10-20 minutes, and intravenous administration is immediately changed after 2-3 times when the effect is not obvious;
2.If persistent severe hypertension develops during the use of oral antihypertensive drugs**, intravenous antihypertensive methods should be considered;
3.After the blood pressure reduction is achieved, it is still necessary to closely monitor the blood pressure changes (e.g., every 10 minutes for 1 hour, then every 15 minutes for 1 h, then every 30 minutes for 1 h, and then every 1 hour for 4 h).
05 Maternal and child monitoring during blood pressure reduction.
1.Mothers monitor changes in body weight and urine output; Observe closely for self-conscious symptoms, such as abdominal pain and bleeding. Epigastric pain, neurological symptoms, etc., to assess the condition and the occurrence of serious complications; monitoring of blood pressure adjustment medications; Tests to monitor the function of the fundus, vital organs, coagulation function, blood lipids, blood uric acid levels, urine protein quantification and electrolyte levels, etc.; Magnesium sulfate is used to monitor magnesium ions and calcium ions; and**Assess the condition, discontinue or start magnesium sulfate.
2.Fetal monitoring of fetal movement changes, fetal heart rate, umbilical cord blood flow, fetal growth and development, and amniotic fluid volume.
06 Table 3 of commonly used antihypertensive drugs: commonly used oral drugs during pregnancy.
*Table 4: Common intravenous drug use during pregnancy**.
07Summary In order to prevent severe hypertension and complications, actively lower blood pressure** Antihypertensive drugs: the first choice of starting drugs: labetalol, nifedipine, methyldopa; Nifedipine tablets are selected for hypertensive emergencies.
Prohibited drugs: ACE inhibitor ARB class Timely and standardized application of oral drugs Try to use a single drug as much as possible, combine drugs with poor effect, if a combination of drugs is required, combine with short-acting + long-term effects, and adjust the medication time according to the time of blood pressure fluctuations Choose different intravenous drugs according to the different indications of pregnant women, if inpatients have taken oral drugs to lower blood pressure and have severe hypertension again, they can directly lower blood pressure intravenously without choosing oral nifedipine tablets Nitroprusside is the last drug to be used Maternal and child monitoring should be done during the blood pressure lowering process.