Discussion
Pulmonary hypertension is one of the most serious complications of
parturient women. Because of special pathophysiological mechanism, there
are some different treatments on liquid balance, anesthesia, operation,
postoperative treatment and ventilator settings. A study on the outcome
of 151 women with pulmonary hypertension showed that although the
general mortality rate dropped to 4.6% (7 / 151), the mortality rate of
idiopathic pulmonary arterial hypertension (iPAH) was still as high as
42.9% (3 / 7) [1]. PAH is the first group of
pulmonary hypertension classification, with higher risk of complications
and mortality [2]. Because of the atypical
clinical manifestations of PAH, clinicians should have enough vigilance
to find clues and make early diagnosis, which is the most important
first step for the survival of women with PAH [3].
This was a case of maternal death of PAH 5 years ago. She was diagnosed
HELLP syndrome and her possible cause of death was considered pulmonary
embolism. We thought her death was inevitable at that time[4]. Now looking back again, we found there were
some obvious defects and errors in the diagnosis and treatment on the
maternal and it was necessary to discuss it again. If time goes back,
maybe she would avoid death.
First of all, although the patient did not diagnose PAH during
pregnancy, she had obvious dizziness and clubbing fingers, hypoxemia and
increased hemoglobin. An experienced doctor should suspect the
underlying disease of cardiovascular or lung basic diseases and
immediately give a color Doppler echocardiography to find out the cause.
The patient did color Doppler echocardiography on the first day after
the operation and showed an obvious manifestations of high load of right
ventricle, such as right atrium and right ventricle enlargement,
tricuspid valve and pulmonary valve regurgitation, left ventricle
compression becoming smaller, ventricular septum and left ventricular
free wall moving in the same direction, pulmonary artery pressure rose
to 70mmHg. It was no doubt that the diagnosis of severe pulmonary
hypertension. We considered she was an iPAH.
PAH patients have a special pathophysiological mechanism, progressive
right heart failure is the most common cause of deterioration[3]. In patients with severe right heart
insufficiency, the preload reserve function of the right heart is
significantly reduced, and the tension-free or low tension stage is
significantly shortened or disappeared, a very small amount of fluid
change may lead to a significant change in cardiac output and a large
fluctuation in hemodynamics [5]. Because of the
underlying disease of PAH, positive fluid balance and positive pressure
ventilation during operation cause acute aggravation of right precordial
and afterload. The increase of right ventricular pressure compressed the
left ventricle through the interventricular septum, the decrease of left
ventricular volume led to the limitation of diastolic function, the
decrease of cardiac output, and then the decrease of blood pressure and
oxygenation. The spasm of pulmonary artery because of the low blood
pressure and oxygenation aggravated the pulmonary hypertension to enter
the vicious circle of autonomic deterioration.
If time goes back, based on our current understanding of PAH and the
application of critical ultrasound technology, patients will be given
cardiac ultrasound examination immediately after admission to make an
early diagnosis of PAH; obstetricians may be more active in choosing to
terminate pregnancy as soon as possible; anesthesiologists may not
choose general anesthesia and will be more strict in controlling
intraoperative fluid intake, because a study have suggested an
associated between general anesthesia and maternal mortality in women
receiving general compared with neuraxial anesthesia for delivery[6]; ICU physicians may strengthen diuretic
treatment or even choose continuous blood purification treatment, as
well as a lower PEEP, which was a “domino effect” caused by untimely
diagnosis because of the doctors were not alert to PAH.
Secondly, the first week after operation is the peak period of death of
PAH maternal, obviously the ICU physicians at that time were
inexperienced in this respect. The patient’s blood pressure dropped on
the second day after operation, which was exactly the manifestation of
low cardiac output caused by right ventricular overload and compression
of left ventricle. Low blood pressure was the most serious situation of
right heart failure. If time goes back, we will closely monitor
echocardiography to dynamically guide the liquid treatment, increase the
dosage of diuretics or actively apply continuous blood purification to
reduce the right heart load and to promote the extent of reverse fluid
resuscitation. Prone position ventilation can reduce the pulmonary
artery pressure and extracorporeal membrane oxygenation(ECMO)
treatment can improve oxygenation and pulmonary artery spasm, which
would also be considered.
Unfortunately, this patient had severe preeclampsia with hypoproteinemia
and partial HELLP syndrome. It has been reported that the proportion of
PAH with severe preeclampsia was as high as 6.7%[7]. On the first day after the operation, the
patient’s hemoglobin decreased, but there was no obstetric hemorrhage
and serious infection. At that time, we explained the decrease of
hemoglobin by Hellp syndrome. If time goes back,we will also consider
maybe hemodilution was another reason for a dropped hemoglobin level,
because of the change of postpartum hormone level and the release of
abdominal pressure as well as the fluid of peripheral tissue edema in
severe preeclampsia returned to the great vessels. This kind of internal
liquid infusion quietly increased the preload of right heart and misled
clinicians to set a small goal for negative fluid balance in patients.
In the second day after operation, due to the insufficient consideration
of endogenous fluid reflux in patients with severe preeclampsia, the
wrong decision to reduce the dosage of diuretics accelerated the
patients’ right heart failure and death.
Although the WHO against pregnancy for PAH women, the actual situation
was that PAH women had a significant increase in the trend[3]. Although time can not goes back, the
experiences of this case five years ago will help us more better in the
next time. In summary, when severe preeclampsia met PAH, clinicians
should strengthen their vigilance in the early diagnosis of PAH, be
familiar with the pathophysiological characteristics of right heart
failure, do a good job on reverse fluid resuscitation, especially should
enlarge the amount of negative fluid balance considered the endogenous
fluid transfer; strengthen the close monitoring and treatment of
hemodynamics guided by intensive ultrasound; emphasize a
multidisciplinary team(MDT) that including obstetricians,
anesthesiologist, ICU physician and cardiologist.
Patient’s consent: We have obtained the permission to publication from
the patient’s family.
REFERENCES
[1] Karen Sliwa, Iris M. van Hagen, Werner Budts, Lorna Swan,
Gianfranco Sinagra et al. Pulmonary hypertension and pregnancy outcomes:
data from the registry of pregnancy and cardiac disease (ROPAC) of the
European society of cardiology. European Journal of Heart Failure. 2016,
18, 1119–1128
[2] Meng ML, Landau R, Viktorsdottir O, Banayan J, Grant T, et al.
Pulmonary hypertension in pregnancy: a report of 49 cases at four
tertiary North American sites. Obstet Gynecol 2017,129:511–20.
[3] Stephanie R. Martin, Alexandra Edwards. Pulmonary hypertension
and pregnancy. Obstetrics & Gynecology. 2019, 134(5): 974-987.
[4] Liu Yuqi, Guoliang Tan, Shang Chengming, Sun Xuri. The ICU is
becoming a mian battlefield for severe maternal rescure in China: an
8-year single center clinical experience. CCM. 2017, 45(11): e1106-1110
[5] Pinsky MR. My paper 20 years later: effect of positive
end-expiratory pressure on right ventricular function in humans.
.Intensive Care Med,. 2014, 40(7): 935-941
[6] Jais X, Olsson KM, Barbera JA, Blanco I, Torbicki A, et al.
Pregnancy outcomes in pulmonary arterial hypertension in the modern
management era. Eur Respire J 2012, 40:881–5.
[7]
Erin Thomas, Jie Yang, Jianjin Xu, Fabio V. Lima, Kathleen
Stergiopoulos. Pulmonary hypertension and pregnancy outcomes: insights
from the national inpatient sample. J Am Heart Assoc. 2017, 6:
e006144-6156