Œdème pulmonaire aigu lors d’une menace d’accouchement prématuré : rôle de la tocolyse par la nicardipine

Use of continuous infusion of nicardipine to control persistent postpartum hypertension: A retrospective study

To evaluate the effect of continuous infusion of nicardipine on the management of uncontrolled blood pressure (BP) during postpartum period. This retrospective study included 209 women diagnosed in hospital with hypertensive disorders during pregnancy and had uncontrolled BP after delivery between January 2018 to December 2020 Uncontrolled BP was defined as persistent elevation of systolic BP ≥ 160 mm Hg or diastolic BP ≥ 110 mm Hg. Patients were divided into 2 groups: nicardipine (N = 53; continuous nicardipine infusion and additional bolus of labetalol or hydralazine) and control (N = 156; consecutive bolus of labetalol or hydralazine). BP data were analyzed using the Mann-Whitney U and χ2 tests by dividing the time interval of 4 hours by the delivery time. The highest BP trends showed that the mean values of both systolic and diastolic BP immediately before delivery were higher in the nicardipine group than in the control. After 8 to 12 hours following delivery, both systolic and diastolic BP were lower in the nicardipine group than in the control. Subsequently, 16 to 20 hours after delivery, both systolic and diastolic BP were significantly lower in the nicardipine group than in the control (137/80 vs 141/84 mm Hg). Initially, the proportions of uncontrolled BP in the nicardipine group were higher than those in the control; however, it then became lower at all time intervals 8 hours after delivery. The proportions of patients who received additional antihypertensive agents and the median cumulative dosages were lower in the nicardipine group than in the control. Continuous infusion of nicardipine can help manage uncontrolled BP during the postpartum period.

Hemodynamic effects of intravenous nicardipine in severely pre-eclamptic women with a hypertensive crisis

OBJECTIVE

Nicardipine permits rapid control of blood pressure in women with severe pre-eclampsia (PE) and hypertensive crisis. Our objective was to investigate its maternal and fetal hemodynamic effects.

METHODS

Ten severely pre-eclamptic pregnant women who required intravenous nicardipine for severe hypertension were included in this prospective observational trial. Maternal macrocirculation was assessed by transthoracic echocardiography. Maternal microcirculatory perfusion was examined sublingually with the sidestream dark field imaging technique. Fetal hemodynamics were assessed by Doppler examinations of the uteroplacental and fetal circulations. Maternal cardiac output, total vascular resistance, mitral E/A ratio and capillary heterogeneity index, uterine artery pulsatility index and fetal cerebroplacental ratio were considered primary outcomes. Paired measurements, obtained before administration of nicardipine infusion and after stabilization of blood pressure, were compared.

RESULTS

Administration of nicardipine significantly reduced the mean arterial blood pressure (median difference, 26 mmHg; P = 0.002) and total vascular resistance (median difference, 791 dynes × s/cm(5) ; P = 0.002) in all included women. This induced a reflex tachycardia with consequent increase in cardiac output of 1.55 L/min (P  =  0.004). There were no significant changes in the other determinants of maternal or fetal hemodynamic parameters.

CONCLUSIONS

Nicardipine effectively reduces blood pressure through selective afterload reduction that triggers an increase in cardiac output, without affecting maternal diastolic function, or microcirculatory, uteroplacental or fetal perfusion. This hemodynamic response is uniform and predictable. Fetomaternal cardiovascular profiling can be achieved by combining transthoracic echocardiography with obstetric Doppler.

[Adverse effects and hemodynamic effects of nifedipine as a tocolytic]

OBJECTIVES

To describe maternal and fetal adverse effects, in particular cardiorespiratory, of nifedipine as tocolytic, as well as effects on hemodynamic parameters.

MATERIALS AND METHODS

A retrospective evaluative study describing the use of nifedipine as tocolytic at CHU Sainte-Justine in Montreal. Demographic data as well as maternal blood pressure and adverse effects, and maternal and fetal heart rate were collected from medical records of women treated with nifedipine following our tocolysis protocol between January 1st 2004 and March 1st 2007.

RESULTS

The medical records of 213 pregnant women were included in the study. Cardiorespiratory adverse effects were noted in 69 (32.4%); of these, 19 (8.9%) had serious cardiorespiratory adverse events, including 6 acute pulmonary edema or overload. Mean maternal systolic and diastolic blood pressures were significantly decreased and mean maternal and fetal heart rates were significantly increased after the bolus dose. Other adverse effects were reported for 100 (46.9%) women.

CONCLUSION

Nifedipine may cause cardiorespiratory adverse effects warranting a close monitoring.

Effect of magnesium sulfate and nifedipine on the risk of developing pulmonary edema in preterm births

OBJECTIVE

To evaluate the risk of developing pulmonary edema in women exposed to nifedipine, magnesium sulfate (MgSO4), or both in a preterm setting.

STUDY DESIGN

We carried out a retrospective case-control study at a large tertiary care center from 2007 to 2012. Cases of pulmonary edema were age, and gestational age matched to controls at a ratio of 1 case to 4 controls. Logistic regression analysis was used to estimate the effect of nifedipine and/or MgSO4 on the development of pulmonary edema while controlling for predetermined confounding variables. Stepwise logistic regression analysis was used to evaluate additional risk factors of pulmonary edema.

RESULTS

A total of 150 charts were reviewed (28 cases and 122 controls). Nifedipine did not increase the odds of developing pulmonary edema [adjusted odds ratio (OR)=1.22 (confidence interval (CI) 0.50, 3.01), P=0.67], whereas exposure to MgSO4, or both MgSO4 and nifedipine, significantly increased the risk of developing pulmonary edema [adjusted OR=3.91 (CI 1.44, 10.65), P=0.008 and adjusted OR=4.75 (CI 1.15, 19.71), P=0.032, respectively]. In the stratified analysis, this association persisted even in nonpreeclamptic women [nifedipine: adjusted OR=0.91 (CI 0.33, 2.52), P=0.852; MgSO4: adjusted OR=3.51 (CI 1.26, 9.76), P=0.016; both: adjusted OR=3.39 (0.76, 15.07), P=0.108]. Other independent risk factors for pulmonary edema were multi-fetal pregnancy, azithromycin, and erythromycin administration.

CONCLUSION

MgSO4 treatment is strongly associated with the development of pulmonary edema when used either as a tocolytic agent or for seizure prophylaxis. In light of the availability of safer alternatives, MgSO4 should be used for tocolysis only in cases whereby the benefits clearly outweigh the risks.

Nicardipine-induced acute pulmonary edema: a rare but severe complication of tocolysis

We report four cases of acute pulmonary edema that occurred during treatment by intravenous tocolysis using nicardipine in pregnancy patients with no previous heart problems. Clinical severity justified hospitalization in intensive care unit (ICU) each time. Acute dyspnea has begun at an average of 63 hours after initiation of treatment. For all patients, the first diagnosis suspected was pulmonary embolism. The patients' condition improved rapidly with appropriate diuretic treatment and by modifying the tocolysis. The use of intravenous nicardipine is widely used for tocolysis in France even if its prescription does not have a marketing authorization. The pathophysiological mechanisms of this complication remain unclear. The main reported risk factors are spontaneous preterm labor, multiple pregnancy, concomitant obstetrical disease, association with beta-agonists, and fetal lung maturation corticotherapy. A better knowledge of this rare but serious adverse event should improve the management of patients. Nifedipine or atosiban, the efficiency of which tocolysis was also studied, could be an alternative.

Calcium channel blockers as tocolytics: principles of their actions, adverse effects and therapeutic combinations

Dihydropyridine Ca²⁺ channel blockers (CCBs) are widely accepted in the treatment of premature labour. Their mechanism of action in tocolysis involves the blockade of L-type Ca²⁺ channels, influenced by the Ca²⁺-activated K⁺ channels, beta-adrenergic receptors (β-ARs) and sexual hormones. In clinical practice, most experience has been gained with the use of nifedipine, whose efficacy is superior or comparable to those of β-agonists and oxytocin antagonists. Additionally, it has a favourable adverse effect profile as compared with the majority of other tocolytics. The most frequent and well-tolerated side-effects of CCBs are tachycardia, headache and hypotension. In tocolytic therapy efforts are currently being made to find combinations of tocolytic agents that yield better therapeutic action. The available human and animal studies suggest that the combination of CCBs with β-AR agonists is beneficial, although such combinations can pose risk of pulmonary oedema in multiple pregnancies and maternal cardiovascular diseases. Preclinical data indicate the potential benefit of combinations of CCBs and oxytocin antagonists. However, the combinations of CCBs with progesterone or cyclooxygenase inhibitors may decrease their efficacy. The CCBs are likely to remain one of the most important groups of drugs for the rapid inhibition of premature uterine contractions. Their significance may be magnified by further clinical studies on their combined use for tocolysis.

Infiltrative lung diseases in pregnancy

Pregnancy may affect the diagnosis, management, and outcome of infiltrative lung disease (ILD). Conversely, ILD may affect pregnancy. ILD may occur as a result of drugs administered commonly or specifically during pregnancy. Most ILDs predominate in patients older than 40 years and are thus rare in pregnant women. During pregnancy ILD may arise de novo and preexisting ILD may be exacerbated or significantly worsened. Some ILDs generally do not alter the management of pregnancy, labor, or delivery. Preexisting ILD no longer contraindicates pregnancy systematically, but thorough evaluation of ILD before pregnancy is required to identify potential contraindications and adapt monitoring.

[Nifedipine or nicardipine in management of threatened preterm delivery: an observational population-based study]

OBJECTIVE

For the first line tocolysis, calcium channel blockers (CCB)--oral nifedipine (Adalate®) or intravenous nicardipine (Loxen®)--are frequently used in France. No study compared nifedipine and nicardipine in management of threatened preterm delivery. From data of a French observational study, we compared factors associated with the use of nifedipine and nicardipine. Efficacy and tolerance of the two treatments were also compared.

METHODS

It was a secondary analysis of EVAPRIMA study, a practice survey describing management of threatened preterm delivery in 107 French maternity units. Only women who received calcium channel blockers in their first line tocolytic therapy were included. We studied obstetrical factors associated with the choice of nifedipine or nicardipine. We also analyzed factors associated with a delivery within seven days following admission using univariate and multivariate analysis. Adverse secondary effects were compared between women who received nifedipine or nicardipine.

RESULTS

Three hundred and four women received calcium channel blockers for their first line tocolytic therapy, in 73 maternity units: 93 (30.6%) women received oral nifedipine and 211 (69.4%) intravenous nicardipine. The same CCB was always prescribed in 69 maternity units. Admission after in utero transfer was less frequent among women who received nifedipine (6.5% versus 17.1%, P=0.01). Premature rupture of the membranes was also less frequent among women who received nifedipine (4.3% versus 13.7%, P=0.02), in comparison with women who received nicardipine. Median duration between admission for threatened preterm labor and delivery was longer when nifedipine was used (44 days versus 36 days, P=0.04). After adjustment on obstetrical factors, the risk to have a delivery within 7 days following admission was not significantly different between nifedipine and nicardipine groups (adjusted OR=0.5 [0.2-1.2]). Among women who received nifedipine only two cases (2.1%) of adverse event were reported with only one case needing a switch of treatment. Thirteen (6.2%) cases of adverse event were reported among women who received nicardipine (P=0.16); in three cases it motivated a switch. However, due to bias and limits inherent in such studies, our results should be interpreted cautiously.

CONCLUSION

Nicardipine is the first choice for French obstetricians in management of severe threatened preterm delivery. However, intravenous nicardipine does not increase gestational duration in comparison with oral nifedipine.

K+ channel openers restore verapamil-inhibited lung fluid resolution and transepithelial ion transport

Background

Lung epithelial Na⁺ channels (ENaC) are regulated by cell Ca²⁺ signal, which may contribute to calcium antagonist-induced noncardiogenic lung edema. Although K⁺ channel modulators regulate ENaC activity in normal lungs, the therapeutical relevance and the underlying mechanisms have not been completely explored. We hypothesized that K⁺ channel openers may restore calcium channel blocker-inhibited alveolar fluid clearance (AFC) by up-regulating both apical and basolateral ion transport.

Methods

Verapamil-induced depression of heterologously expressed human αβγ ENaC in Xenopus oocytes, apical and basolateral ion transport in monolayers of human lung epithelial cells (H441), and in vivo alveolar fluid clearance were measured, respectively, using the two-electrode voltage clamp, Ussing chamber, and BSA protein assays. Ca²⁺ signal in H441 cells was analyzed using Fluo 4AM.

Results

The rate of in vivo AFC was reduced significantly (40.6 ± 6.3% of control, P < 0.05, n = 12) in mice intratracheally administrated verapamil. K_Ca3.1 (1-EBIO) and K_ATP (minoxidil) channel openers significantly recovered AFC. In addition to short-circuit current (Isc) in intact H441 monolayers, both apical and basolateral Isc levels were reduced by verapamil in permeabilized monolayers. Moreover, verapamil significantly altered Ca²⁺ signal evoked by ionomycin in H441 cells. Depletion of cytosolic Ca²⁺ in αβγ ENaC-expressing oocytes completely abolished verapamil-induced inhibition. Intriguingly, K_V (pyrithione-Na), K _Ca3.1 (1-EBIO), and K_ATP (minoxidil) channel openers almost completely restored the verapamil-induced decrease in Isc levels by diversely up-regulating apical and basolateral Na⁺ and K⁺ transport pathways.

Conclusions

Our observations demonstrate that K⁺ channel openers are capable of rescuing reduced vectorial Na⁺ transport across lung epithelial cells with impaired Ca²⁺ signal.

L'œdème aigu du poumon chez des patientes en menace d'accouchement prématuré traitées par inhibiteurs calciques: place de facteurs prédisposants ou pharmacologiques spécifiques?

Calcium channel blockers of the dihydropyridin's family have been associated with the onset of an acute pulmonary edema when they are used as a treatment of preterm labor. We report here four cases of pulmonary edema in pregnant women treated with nicardipine (Loxen) for preterm labor. The physiopathology of pulmonary edema, the pharmacology of calcium channel blockers of dihydropyridin's family and the detailed analysis of our cases and those of the literature make us discuss of the role of these agents and associated population and risk factors in such complication.