Role of the Nitric Oxide (NO) in Pre-oxygenation Before Anesthetic Induction in Patients With a Pulmonary Hypertension in Cardiac Surgery. Pilot Study of Feasibility
Role of the Nitric Oxide (NO) in Pre-oxygenation Before Anesthetic Induction in Patients With a Pulmonary Hypertension in Cardiac Surgery. Pilot Study of Feasibility
The pulmonary hypertension (HTP) due to a left heart disease or a hypoxemiant lung disease is
 frequent in cardiac surgery. The HTP represents an independent risk factor of morbidity and
 mortality in cardiac surgery, entering to the criteria of Euroscore evaluation (European
 System for Cardiac Operative Risk Evaluation).

 An acute perioperative hemodynamic decompensation of these patients is frequent.
 Perioperative hemodynamic modifications, hypoxemia, hypercapnia, sympathetic stimulation,
 increase pulmonary vascular resistances (RVP) and might provoke right ventricular failure.

 The anesthetic induction and the beginning of mechanical ventilation are the most sensible
 times due to the risk of hemodynamic decompensation. The suppression of the sympathetic tonus
 which is consequence of the anesthetic induction, decrease the systemic vascular resistances
 and lead to decrease of blood pressure. In return, the anesthetic induction is associated
 with an increase of pulmonary vascular resistances, resulting in increase of the postcharge
 and the work of the right ventricle (VD). These systemic and pulmonary hemodynamic
 modifications can lead to equalization, or even an inversion of the systemic and pulmonary
 pressures. As consequence, a hemodynamic collapse or even a heart arrest can arise.

 The patients suffering from HTP are hypoxemic. They have very limited oxygen reserves due to
 decrease of the functional residual capacity (CRF). The apnea period, which follows the
 anesthetic induction, is often associated with a fast desaturation, even if a good
 pre-oxygenation was performed before. This desaturation causes an increase of the pulmonary
 vascular resistances with the hemodynamic consequences previously mentioned. A risk of
 hypoxic heart arrest is also present.

 Nitric Oxide (NO) is an endogenous mediator produced from the vascular endothelium. The NO is
 a powerful vasodilator and is used in intensive care in inhaled way as selective pulmonary
 vasodilator (iNO). NO decreases the RVP, the shunt effect and improves the oxygenation by
 optimization of ventilation-perfusion ratio. The short lifetime of iNO (6sec approximately)
 allows a fast metabolism without inducing any undesirable effects such as the systemic
 hypotension.

 No studies, until now, have investigated the use of iNO in pre-oxygenation before anesthetic
 induction in cardiac surgery.

 We hope to demonstrate that iNO used in oxygenation before anesthetic induction will have a
 beneficial effect on the respiratory and cardiovascular parameters.

 Our objective is to estimate the feasibility and the tolerance of iNO before anesthetic
 induction of the patients with a moderate or severe HTP programmed for cardiac surgery with
 extracorporeal circulation. The effect will be estimated in terms of efficiency (hemodynamic
 and respiratory optimization).
Before the anesthetic induction every included patient will follow these protocol:

 -  Standard monitoring (ECG Electrocardiogram, SpO2 Pulsed oxygen saturation)

 -  Insertion of radial arterial line and periferic IV line under local anesthesia,

 -  Insertion of a internal jugular central line and Swan Ganz catheter under local
 anesthesia

 -  Preoxygenation in 100% oxygen for 10 min

 -  Further preoxygenation with a mixture of 100% oxygen associated with the iNO in a dose
 of 1,2 L / mn.

 -  Anesthesia induction and initiation of mechanical ventilation.

 -  Progressive decrease of iNO dose and stop of iNO administration.
Inclusion Criteria:

 - Age > 18 years old

 -  Open-heart cardiac surgery

 -  HTP Pulmonary hypertension (class 2 or 3) with PAPs (Systolic pulmonary artery
 pressure) > 40 mmHg diagnosed by preoperative righ cardiac catheterization or by
 transthoracic echocardiography.

 -  Patient have signed their consent according to the modalities described by the Code of
 Public health system.

 -  Patients affiliated to a national insurance (social security) system.

 Exclusion Criteria:

 -  Heart transplant

 -  HTP of type 1, 4, 5 according to the classification of Dana Point(2008)

 -  Deficit in methemoglobin reductase

 -  Protocole refuse from patient