Asma en embarazadas
10
October

By Adem Lewis / in , , , , , /


The objectives for asthmatic pregnant
women are similar to those established for the asthmatic population at large: control symptoms, improve lung function, prevent exacerbations, and minimise, to the extent possible, the side effects of
the medication used. In addition to the shared objectives,
with asthmatic pregnant women, the ultimate goal is for her to
give birth to a healthy child, while at the same time ensuring the
safety of the women bearing said child. It is important to keep asthma
under control during pregnancy because otherwise, it can
significantly impact both maternal as well as
foetal morbidity and mortality. Asymptomatic pregnant women
run a higher risk of uterine haemorrhage, hospital stays, premature birth, induced labour, C-sections, continuous, intense vomiting, which prevents the expectant mother
from getting proper nutrition and which could lead to
dehydration, which is known as hyperemesis gravidarum, high blood pressure associated
with proteinuria—also known as pre-eclampsia— and placenta previa, where the placenta
is positioned in the lower third of the uterus, which can block the
opening to the cervix and is a major cause of bleeding during the
first trimester of pregnancy. As for foetal risks, it may experience retarded intrauterine growth
and have a low birth weight. It is important to know proper
asthma treatment, since undertreating is the most common error in the treatment of
asthmatic pregnant women. There are two main treatment groups for asthma.: First, we have bronchodilators, which can,
in turn be subdivided into three categories: first we have beta-2 adrenergic agonists.
These bronchodilators can be of two varieties: short-acting (like salbutamol and terbutaline), which are both safe during pregnancy, and long-acting (like salmeterol and formoterol), which we should reserve
for patients with severe night-time symptoms that make it difficult
for them to fall asleep. Secondly, we have anticholinergics. Ipratropium bromide is
safe during pregnancy. Lastly, we have theophylline, though it is not widely used.
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Although it does not
increase teratogenicity, it requires on-going monitoring of
concentrations at the serum level, on account of the fact that during the third trimester of
pregnancy, theophylline washing is reduced by as much as 20%. The second treatment group
is anti-inflammatories, which can be sub-divided as follows: First, we have corticoids,
which can be inhaled (budesonide and beclometasone are
the inhaled corticoids of choice— we will reserve fluticasone for patients with asthma) and which require high doses, or, alternatively, corticoids may be administered
systemically. Prednisone, methylprednisolone and
prednisolone are the drugs of choice here. Systemic corticoids are
crucial when treating severe acute asthma. They are also
essential for managing severe acute asthma during pregnancy. Short-term use is safe and does not increase
perinatal mortality. Long-term use may
lead to hyperglycaemia and the effects associated thereto. We also have antileukotriene
drugs, montelukast and zafirlukast. Routine use is not
recommended during pregnancy and will be reserved for
asthmatic pregnant women with poorly-managed asthma, provided they used these drugs
prior to the pregnancy, with good results. There are other treatment groups
which we may, at times, need to use with asthmatic pregnant women, such as membrane stabilising drugs like
nedocromil and cromoglycate. Cromoglycate is the drug of choice and is reserved for asthmatic patients with persistent asthma, provided they used these drugs prior
to the pregnancy, with good results. Immunotherapy, on the other hand, should
not be initiated during pregnancy, though it also shouldn’t be suspended in patients who are already under this
treatment, provided that they tolerate it well. We will use antihistamines with
asthmatic pregnant women in whom allergic rhinitis
causes significant discomfort. In any case, first line treatment
for allergic rhinitis should be cromoglycate or topical nasal corticoids added to normal saline solution
or a hypertonic solution. We will reserve antihistamines for cases where it
is most necessary, since they can pass
through the placental barrier. Cetirizine, loratadine and desloratadine
should be used, since they are considered among the lower-risk decongestant drugs. If necessary, during the
first trimester we can use oxymetazoline, though not for
more than 2-3 consecutive days. If we need to use this kind of drug
during the second or third trimester, pseudoephedrine is the drug of choice. Asthma exacerbation should be
considered a medical emergency and should be treated as it would be
in the case of any other asthma patient. The severity of the exacerbation
is determined by the anamnesis, the patient’s physical exam, and the results of complimentary testing. With the patient’s physical exam, we should pay close attention
to heart rate, respiration rate, use of accessory muscles, and the presence or absence
of wheezing upon auscultation. When reading the arterial blood gas
of an asthmatic pregnant patient, we must factor in several
physiological considerations. During the first trimester of pregnancy,
as a result of the increase in progesterone, hyperventilation may occur. This may lead to a decrease PCO2 and
an increase in pH,. This means that respiratory alkalosis is
physiological during pregnancy. Therefore, when reading the arterial
blood gas during an asthma crisis, a PO2 level below 70 mmHg would be considered serve hypoxia, and a
PCO2 level above 35 mmHg acute respiratory failure. Patient management in the A&E
is based on three main pillars: first and foremost,
oxygen therapy, to maintain a saturation
of 94-98% and avoid both maternal and foetal hypoxia. Secondly, we have nebulised short-acting beta-2
agonists—we will use salbutamol in doses of 2.5 to 5 mg diluted in 3 cm3 of physiological
saline solution. We would recommend a maximum of 3
nebulisations during the first 90 minutes, subsequently spacing them
out every hour or two according to the patient’s response to the nebulisation. We often
add ipratropium bromide is doses of 250 to 500 mcg, since it acts in conjunction
with salbutamol to improve bronchodilator function without increasing side effect. The third pillar is
systemic corticoids. We will use them when the patient’s signs and symptoms
do not show clear improvement with bronchodilator treatment. Methylprednisolone is the drug of choice, in doses of 1-2 mg
per kg, IV, in bolus. The dose should subsequently be reduced to 60-80 mg every 12 hours according
to the patient’s response. Poorly-managed asthma has a profound
impact on maternal and foetal morbidity and mortality. When left unmanaged, asthma is more dangerous
for the mother and foetus than possible occasional side effects that could arise as a result
of proper use of the medication. Asthma in pregnant women should be treated
the same way it would be in all other asthmatic patients. The treatment base is bronchodilators, and if the intensity
is moderate or severe, anti-inflammatory treatment
should be added. We should educate asthmatic expectant
mothers to: recognise early warning signs and symptoms of exacerbation, use the medications properly, avoid exposure to environmental
factors that are triggers for them, and to quit smoking.


2 thoughts on “Asma en embarazadas

  1. yo tengo 6 meses de embarazo y staba usando salbutamol beclometasona por inhalación y estaba muy asustada xq me dijern q no lo podia usar porque mi bb hiba a nacer sin lengua y mal formado pero gracias a su video toda esas dudas se han ido gracias

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