GapCO2 and Respiratory Rate in Patients Under Volume Mechanical Ventilation (gapCO2)

105 Hospital of Chinese People's Liberation Army

Status

Unknown

Conditions

Shock

Treatments

Other: Effects of respiratory rate on gapCO2

Study type

Observational

Funder types

Other

Identifiers

NCT02867943

PLA-105-ICU

Details and patient eligibility

About

As an approximate of the difference between venous-to-arterial CO2 tension (∆PCO2), ∆PCO2 is proportional to CO2 production and inversely related to cardiac output (Fick equation). Anaerobic CO2 production is thought to occur when tissue hypoxia is present, mostly because of buffering of bicarbonate ions by the protons produced in excess secondary to the hydrolysis of adenosine triphosphate. Therefore ∆PCO2 has been proposed as a marker of tissue hypoxia.

Full description

An increased ∆PCO2 (> 6 mmHg) could be used to identify patients who still remain inadequately resuscitated, when deciding when to continue resuscitation despite a central venous oxygen saturation (ScvO2) > 70% associated with elevated blood lactate levels.

Under steady states of both VO2 and VCO2, P (v-a) CO2 was observed to increase in parallel with the reduction in cardiac output. However, spontaneous breathing and hyperventilation may reduce PaCO2 and prevent the CO2 stagnation-induced rise in PvCO2.

To date,these studies of ∆PCO2 and respiratory rate in septic shock patients Under Volume Mechanical Ventilation are rarely.

Enrollment

28 estimated patients

Sex

All

Ages

18 to 90 years old

Volunteers

No Healthy Volunteers

Inclusion criteria

Patients were included in the study, if the attending physician find the persistence of signs of hypoperfusion (oliguria, mottled skin, central venous oxygen saturation (ScvO2) <70 % despite a hemoglobin > 8 g/dl),despite achieving adequate intravascular volume and adequate mean arterial pressure (MAP) > 65 mmHg as recommended by the Surviving Sepsis Campaign.

Exclusion criteria

Exclusion criteria were pregnancy, COPD，age less than 18 years old, unstable hemodynamic condition (change of vasoactive drug dosage or fluid administration within 1 h preceding the protocol) and uncontrolled tachyarrhythmias (heart rate>140 beats/min).