Cardiovascular Journal of Africa: Vol 31 No 2 (March/April 2020)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 31, No 2, March/April 2020 AFRICA 71
Sevoflurane- and propofol-based regimens show
comparable effect on oxygenation in patients undergoing
cardiac valve replacement with cardiopulmonary bypass
Zhen Luo, Xiaozhen Wei, Yunxia Zuo, Guizhi Du
Abstract
Background: Our study aimed to compare the effects of
sevoflurane- and propofol-based anaesthetic regimens on
oxygenation during the early period of cardiopulmonary
bypass (CPB) in patients undergoing cardiac valve-replace-
ment surgery.
Methods: Patients undergoing mechanical mitral, aortic or
double valve replacement were enrolled and randomly divided
into two groups: the sevoflurane-based anaesthetic regimen
group consisted of patients who received 1–3% sevoflurane
inhalation during anaesthesia maintenance and the propofol-
based anaesthetic regimen group consisted of patients who
received 6–10 mg/kg/h of propofol infusion during anaes-
thesia maintenance. The partial pressure of oxygen/fraction
of inspired oxygen (PaO2/FiO 2), respiratory mechanics and
haemodynamics were recorded during CPB.
Results: Forty-two patients met the eligibility criteria for the
study. The groups did not differ in terms of clinical and demo-
graphic characteristics, and pre- and intra-operative features.
Changes in oxygenation were mild (mean PaO2/FiO2 from
358 ± 82 to 471 ± 106 mmHg) within one hour of CPB in our
patients. There were no differences in PaO2/FiO 2, respiratory
mechanics and haemodynamics between the sevoflurane and
propofol groups.
Conclusion: In patients undergoing cardiac valve replace-
ment with CPB, lung injury was mild, and sevoflurane- and
propofol-based anaesthetic regimens showed similar effect
on oxygenation, respiratory mechanics and haemodynamics
during the early stage of CPB.
Keywords: oxygenation, sevoflurane, propofol, cardiac valve
replacement, cardiopulmonary bypass
Submitted 29/1/19, accepted 1/9/19
Published online
Cardiovasc J Afr 2019; 31: 71–74
DOI: 10.5830/CVJA-2019-050
During cardiopulmonary bypass (CPB), the lung is subjected to
ischaemia/reperfusion injury and systemic inflammatory response
syndrome.1 Pulmonary complications with variable severity are
common after cardiac surgerywithCPB. However, with improvement
in membrane oxygenation and the development of extracorporeal
circulation, the incidence of lung injury has declined.2
Fast-track cardiac care has been advocated in recent years,
including a complex intervention of several components of care
during cardiac anaesthesia and in the postoperative period. It
has been demonstrated that fast-track anaesthetic techniques
for cardiac surgery contribute to a shorter intensive care unit
(ICU) stay.3
Experimental evidence has documented that propofol, a
widely used intravenous drug for fast-track anaesthetic regimens,
can improve lung function in endotoxin-induced lung injury.4
Volatile anaesthetics are frequently employed in cardiothoracic
surgery, however, the effects of inhalational anaesthetic agents
on pulmonary oxygenation remain controversial.
Recent studies have demonstrated that sevoflurane or
isoflurane could impair oxygenation in oleic acid-induced lung
injury in dogs.5,6 However, in endotoxin-induced lung injury in
rats, sevoflurane improved oxygenation compared to propofol.7
Furthermore, in thoracic aortic occlusion-induced lung injury
in pigs, sevoflurane and propofol showed a similar effect on
oxygenation.8 These results indicate that the effects of sevoflurane
on oxygenation vary with different lung injury models.
The purpose of this study was to evaluate the severity of the
insult on lung oxygenation and the effects of sevoflurane- and
propofol-based anaesthetic regimens on oxygenation during
the early stage of CPB in patients undergoing cardiac valve
replacement surgery. We hypothesised that lung injury would
not be severe and a sevoflurane-based anaesthetic regimen could
not impair oxygenation compared to a propofol-based regimen
during the early period of CPB.
Methods
This prospective, randomised study was approved by the local
institutional ethics committee. Written informed consent was
obtained from every patient. The study was conducted according
to the Declaration of Helsinki.
Patients undergoing mechanical mitral, aortic or double valve
replacement (ASA III) were screened for eligibility. Exclusion
criteria included patients with relevant pulmonary disorders such
as pulmonary oedema, pneumonia, bronchial asthma, acute
respiratory distress syndrome (ARDS), those with pre-operative
pulmonary therapy or pre-operative detected pathological lung-
function tests [vital capacity (VC), forced expiratory volume in one
second (FEV1) and blood gas analysis], and those with an ejection
fraction of less than 30%, significant hepatic disease (alanine
Department of Anaesthesiology, West China Hospital,
Sichuan University, Chengdu, China
Guizhi Du, MD, PhD,
Yunxia Zuo, MD,
Zhen Luo, MD
Xiaozhen Wei, MD