Type A Aortic Dissection
Conditions
Keywords
Hypoxemia, Type A acute aortic dissection, inhaled nitric oxide
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.
Interventions
DRUGinhaled nitric oxide
using of inhaled nitric oxide
DEVICEPEEP
increasing PEEP or decreasing PEEP
Sponsors
Shanghai Zhongshan Hospital
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
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;
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Intrapulmonary shunt with a PEEP of 5 cm H2O | 6 to 24 hours after surgery | intrapulmonary shunt calculated by Fick equation with a PEEP of 5 cm H2O |
| Intrapulmonary shunt with a PEEP of 10 cm H2O | 30 minutes after increasing PEEP to 10cm H2O | intrapulmonary shunt calculated by Fick equation with a PEEP of 10 cm H2O |
| Intrapulmonary shunt with a PEEP of 10 cm H2O and inhaled nitric oxide | 30 minutes after inhaling nitric oxide | intrapulmonary shunt calculated by Fick equation with a PEEP of 10 cm H2O and inhaled nitric oxide |
| Intrapulmonary shunt with inhaled nitric oxide and a PEEP of 5 cm H2O | 30 minutes after decreasing PEEP to 5cm H2O | intrapulmonary shunt calculated by Fick equation with inhaled nitric oxide and a PEEP of 5 cm H2O |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| pulmonary artery pressure collected from PAC with a PEEP of 10 cm H2O | 30 minutes after increasing PEEP to 10cm H2O | pulmonary artery pressure in mmHg |
| pulmonary artery wedge pressure collected from PAC with a PEEP of 10 cm H2O | 30 minutes after increasing PEEP to 10cm H2O | pulmonary artery wedge pressure in mmHg |
| cardiac output collected from PAC with a PEEP of 10 cm H2O and inhaled nitric oxide | 30 minutes after inhaling nitric oxide | cardiac output in L/min |
| pulmonary artery pressure collected from PAC with a PEEP of 10 cm H2O and inhaled nitric oxide | 30 minutes after inhaling nitric oxide | pulmonary artery pressure in mmHg |
| cardiac output collected from PAC with a PEEP of 5 cm H2O | 6 to 24 hours after surgery | cardiac output in L/min |
| cardiac output collected from PAC with inhaled nitric oxide and a PEEP of 5 cm H2O | 30 minutes after decreasing PEEP to 5 cm H2O | cardiac output in L/min |
| pulmonary artery pressure collected from PAC with inhaled nitric oxide and a PEEP of 5 cm H2O | 30 minutes after decreasing PEEP to 5 cm H2O | pulmonary artery pressure in mmHg |
| pulmonary artery wedge pressure collected from PAC with inhaled nitric oxide and a PEEP of 5 cm H2O | 30 minutes after decreasing PEEP to 5 cm H2O | pulmonary artery wedge pressure in mmHg, etc |
| pulmonary artery wedge pressure collected from PAC with a PEEP of 10 cm H2O and inhaled nitric oxide | 30 minutes after inhaling nitric oxide | pulmonary artery wedge pressure in mmHg |
| pulmonary artery pressure collected from PAC with a PEEP of 5 cm H2O | 6 to 24 hours after surgery | pulmonary artery pressure in mmHg |
| pulmonary artery wedge pressure collected from PAC with a PEEP of 5 cm H2O | 6 to 24 hours after surgery | pulmonary artery wedge pressure in mmHg |
| cardiac output collected from PAC with a PEEP of 10cm H2O | 30 minutes after increasing PEEP to 10cm H2O | cardiac output in L/min |
Countries
China
Contacts
Primary ContactZhe Luo, PhD
Outcome results
None listed