Clinical trial NCT04032366: iNO as Salvage Treatment of Hypoxemia After TAAD Surgery
Official title: Inhaled Nitric Oxide as Salvage Treatment of Hypoxemia After Type A Acute Aortic Dissection Surgery (INSTEAD)
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Type A Aortic Dissection
Keywords: Hypoxemia
Type A acute aortic dissection
inhaled nitric oxide
Lead sponsor: Shanghai Zhongshan Hospital
Sponsor class: OTHER
First posted: 2019-07-25
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: post-surgical type A aortic dissection patients with hypoxemia

Brief summary: 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.

Detailed 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.

Eligibility criteria: 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;

Primary outcomes:
measure: Intrapulmonary shunt with a PEEP of 5 cm H2O
timeFrame: 6 to 24 hours after surgery
measure: Intrapulmonary shunt with a PEEP of 10 cm H2O
timeFrame: 30 minutes after increasing PEEP to 10cm H2O
measure: Intrapulmonary shunt with a PEEP of 10 cm H2O and inhaled nitric oxide
timeFrame: 30 minutes after inhaling nitric oxide
measure: Intrapulmonary shunt with inhaled nitric oxide and a PEEP of 5 cm H2O
timeFrame: 30 minutes after decreasing PEEP to 5cm H2O
Secondary outcomes:
measure: cardiac output collected from PAC with a PEEP of 5 cm H2O
timeFrame: 6 to 24 hours after surgery
measure: pulmonary artery pressure collected from PAC with a PEEP of 5 cm H2O
timeFrame: 6 to 24 hours after surgery
measure: pulmonary artery wedge pressure collected from PAC with a PEEP of 5 cm H2O
timeFrame: 6 to 24 hours after surgery
measure: cardiac output collected from PAC with a PEEP of 10cm H2O
timeFrame: 30 minutes after increasing PEEP to 10cm H2O
measure: pulmonary artery pressure collected from PAC with a PEEP of 10 cm H2O
timeFrame: 30 minutes after increasing PEEP to 10cm H2O
measure: pulmonary artery wedge pressure collected from PAC with a PEEP of 10 cm H2O
timeFrame: 30 minutes after increasing PEEP to 10cm H2O
measure: cardiac output collected from PAC with a PEEP of 10 cm H2O and inhaled nitric oxide
timeFrame: 30 minutes after inhaling nitric oxide
measure: pulmonary artery pressure collected from PAC with a PEEP of 10 cm H2O and inhaled nitric oxide
timeFrame: 30 minutes after inhaling nitric oxide
measure: pulmonary artery wedge pressure collected from PAC with a PEEP of 10 cm H2O and inhaled nitric oxide
timeFrame: 30 minutes after inhaling nitric oxide
measure: cardiac output collected from PAC with inhaled nitric oxide and a PEEP of 5 cm H2O
timeFrame: 30 minutes after decreasing PEEP to 5 cm H2O
measure: pulmonary artery pressure collected from PAC with inhaled nitric oxide and a PEEP of 5 cm H2O
timeFrame: 30 minutes after decreasing PEEP to 5 cm H2O
measure: pulmonary artery wedge pressure collected from PAC with inhaled nitric oxide and a PEEP of 5 cm H2O
timeFrame: 30 minutes after decreasing PEEP to 5 cm H2O
Other outcomes:
Locations:
city: Shanghai
country: China
facility: Zhongshan hospital Fudan University
state: Shanghai
Study officials:
affiliation: Fudan University
name: Guo-wei Tu, PhD
role: PRINCIPAL_INVESTIGATOR
References: