iNO as Salvage Treatment of Hypoxemia After TAAD Surgery

Inhaled Nitric Oxide as Salvage Treatment of Hypoxemia After Type A Acute Aortic Dissection Surgery (INSTEAD)

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.

Study Overview

• Status: Unknown
• Conditions: Type A Aortic Dissection
• Intervention / Treatment: Drug: inhaled nitric oxide; Device: PEEP

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.

• Study Type: Observational
• Enrollment (Anticipated): 20

Contacts and Locations

Study Locations

• China
  • Shanghai
    • Shanghai, Shanghai, China, 200030
      • Recruiting
      • Zhongshan Hospital Fudan University
      • Contact: Zhe Luo, PhD; Phone Number: 02164041990 02164041990; Email: ec@zs-hospital.sh.cn
      • Contact: Guowei Tu, PhD; Phone Number: 02164041990 02164041990; Email: ec@zs-hospital.sh.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 76 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

post-surgical type A aortic dissection patients with hypoxemia

Description

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;

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
PEEP 5; post-surgical type A acute aortic dissection patients was ventilated with a PEEP of 5cm H2O, without inhaled nitric oxide
PEEP 10; post-surgical type A acute aortic dissection patients was ventilated with a PEEP of 10cm H2O, without inhaled nitric oxide	Drug: inhaled nitric oxide; using of inhaled nitric oxide; Other Names: iNO; Device: PEEP; increasing PEEP or decreasing PEEP
PEEP 10 +iNO; post-surgical type A acute aortic dissection patients was ventilated with a PEEP of 10cm H2O, with inhaled nitric oxide
PEEP 5 +iNO; post-surgical type A acute aortic dissection patients was ventilated with a PEEP of 5cm H2O, with inhaled nitric oxide	Drug: inhaled nitric oxide; using of inhaled nitric oxide; Other Names: iNO; Device: PEEP; increasing PEEP or decreasing PEEP

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intrapulmonary shunt with a PEEP of 5 cm H2O	intrapulmonary shunt calculated by Fick equation with a PEEP of 5 cm H2O	6 to 24 hours after surgery
Intrapulmonary shunt with a PEEP of 10 cm H2O	intrapulmonary shunt calculated by Fick equation with a PEEP of 10 cm H2O	30 minutes after increasing PEEP to 10cm H2O
Intrapulmonary shunt with a PEEP of 10 cm H2O and inhaled nitric oxide	intrapulmonary shunt calculated by Fick equation with a PEEP of 10 cm H2O and inhaled nitric oxide	30 minutes after inhaling nitric oxide
Intrapulmonary shunt with inhaled nitric oxide and a PEEP of 5 cm H2O	intrapulmonary shunt calculated by Fick equation with inhaled nitric oxide and a PEEP of 5 cm H2O	30 minutes after decreasing PEEP to 5cm H2O

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
cardiac output collected from PAC with a PEEP of 5 cm H2O	cardiac output in L/min	6 to 24 hours after surgery
pulmonary artery pressure collected from PAC with a PEEP of 5 cm H2O	pulmonary artery pressure in mmHg	6 to 24 hours after surgery
pulmonary artery wedge pressure collected from PAC with a PEEP of 5 cm H2O	pulmonary artery wedge pressure in mmHg	6 to 24 hours after surgery
cardiac output collected from PAC with a PEEP of 10cm H2O	cardiac output in L/min	30 minutes after increasing PEEP to 10cm H2O
pulmonary artery pressure collected from PAC with a PEEP of 10 cm H2O	pulmonary artery pressure in mmHg	30 minutes after increasing PEEP to 10cm H2O
pulmonary artery wedge pressure collected from PAC with a PEEP of 10 cm H2O	pulmonary artery wedge pressure in mmHg	30 minutes after increasing PEEP to 10cm H2O
cardiac output collected from PAC with a PEEP of 10 cm H2O and inhaled nitric oxide	cardiac output in L/min	30 minutes after inhaling nitric oxide
pulmonary artery pressure collected from PAC with a PEEP of 10 cm H2O and inhaled nitric oxide	pulmonary artery pressure in mmHg	30 minutes after inhaling nitric oxide
pulmonary artery wedge pressure collected from PAC with a PEEP of 10 cm H2O and inhaled nitric oxide	pulmonary artery wedge pressure in mmHg	30 minutes after inhaling nitric oxide
cardiac output collected from PAC with inhaled nitric oxide and a PEEP of 5 cm H2O	cardiac output in L/min	30 minutes after decreasing PEEP to 5 cm H2O
pulmonary artery pressure collected from PAC with inhaled nitric oxide and a PEEP of 5 cm H2O	pulmonary artery pressure in mmHg	30 minutes after decreasing PEEP to 5 cm H2O
pulmonary artery wedge pressure collected from PAC with inhaled nitric oxide and a PEEP of 5 cm H2O	pulmonary artery wedge pressure in mmHg, etc	30 minutes after decreasing PEEP to 5 cm H2O

Collaborators and Investigators

• Sponsor: Shanghai Zhongshan Hospital

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2019
• Primary Completion (Anticipated): December 31, 2021
• Study Completion (Anticipated): December 31, 2021

Study Registration Dates

• First Submitted: July 16, 2019
• First Submitted That Met QC Criteria: July 23, 2019
• First Posted (Actual): July 25, 2019

Study Record Updates

• Last Update Posted (Actual): February 5, 2020
• Last Update Submitted That Met QC Criteria: February 1, 2020
• Last Verified: July 1, 2019

More Information

Terms related to this study

• Keywords: inhaled nitric oxide; Hypoxemia; Type A acute aortic dissection
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Signs and Symptoms, Respiratory; Aneurysm; Aneurysm, Dissecting; Hypoxia; Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Vasodilator Agents; Autonomic Agents; Peripheral Nervous System Agents; Protective Agents; Bronchodilator Agents; Anti-Asthmatic Agents; Respiratory System Agents; Antioxidants; Free Radical Scavengers; Endothelium-Dependent Relaxing Factors; Gasotransmitters; Nitric Oxide
• Other Study ID Numbers: INSTEAD

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No