iNO as Salvage Treatment of Hypoxemia After TAAD Surgery

Fudan University

Status: Unknown

Conditions: Type A Aortic Dissection

Treatments: Device: PEEP; Drug: inhaled nitric oxide

Study type: Observational

Funder types: Other

Identifiers

NCT04032366

INSTEAD

Details and patient eligibility

About

The purpose of this study was to clarify the possible mechanism of hypoxemia after surgical treatment of type A acute aortic dissection and the possible mechanism of the treatment role of inhaled nitric oxide in refractory hypoxemia.

Full description

The investigators' previous study has stressed that inhaled nitric oxide therapy might play an ameliorative role in patients with refractory hypoxemia after surgical treatment of type A acute aortic dissection. The possible reason might be the decreasing of intrapulmonary shunt because previous studies showed that inhaled nitric oxide could decrease intrapulmonary shunt by selectively dilating the pulmonary vessels in ventilated areas. As a result, the investigators designed this observational study to calculate the intrapulmonary shunt before and after inhaled nitric oxide therapy. Intrapulmonary shunt was calculated from oxygen content (CO2) of different sites ( artery, mixed venous, alveolar capillary) by Fick equation:(CaO2-CcO2)/(CvO2-CcO2). A FiO2 of 1.0 and tidal volume of 6~8 ml/kg were chosen. Oxygen content was calculated from hemoglobin (Hb), oxygen saturation (SO2) and oxygen partial pressure (PO2) by the following equation: CO2 = 1.34*Hb*SO2 + 0,0031*PO2. PaO2, SaO2, PvO2 and SvO2 were measured from arterial and mixed venous blood samples taken from the radial arterial catheter and from the pulmonary artery catheter. ScO2 was estimated to be 1.0 with a FiO2 of 100%. PcO2 was considered to be the same as PAO2 (partial pressure of oxygen in the alveoli), and was calculated from the alveolar gas equation with PAO2 = [(atmospheric pressure - 47) * (FiO2)] - PaCO2/0.8.Other variables such as hemodynamic variables from pulmonary artery catheter were also collected.

Enrollment: 20 estimated patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Adult
• Type A aortic dissection;
• After surgery;
• P/F ratio ≤ 200mmHg

Exclusion criteria

• Intracardiac shunt;
• Contradiction of PAC;
• Chronic pulmonary diseases before surgery;
• ECMO;
• Anticipation of death within 48 hours after operation;

Trial design

20 participants in 4 patient groups

PEEP 5

Description:

post-surgical type A acute aortic dissection patients was ventilated with a PEEP of 5cm H2O, without inhaled nitric oxide

PEEP 10

Description:

post-surgical type A acute aortic dissection patients was ventilated with a PEEP of 10cm H2O, without inhaled nitric oxide

Treatment:

Drug: inhaled nitric oxide

Device: PEEP

PEEP 10 +iNO

Description:

post-surgical type A acute aortic dissection patients was ventilated with a PEEP of 10cm H2O, with inhaled nitric oxide

PEEP 5 +iNO

Description:

post-surgical type A acute aortic dissection patients was ventilated with a PEEP of 5cm H2O, with inhaled nitric oxide

Treatment:

Drug: inhaled nitric oxide

Device: PEEP