Clinical Trial Details
— Status: Suspended
Administrative data
NCT number |
NCT04455789 |
Other study ID # |
AkdenizU-2 |
Secondary ID |
|
Status |
Suspended |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
August 1, 2019 |
Est. completion date |
August 1, 2024 |
Study information
Verified date |
January 2024 |
Source |
Akdeniz University |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Previous studies showed that, best lung protective strategies of ventilation parameters are
based on driving pressure in damaged lungs. But there are few studies concerning the effects
of different positions during different types of surgery on driving pressure with normal
lungs.So the investigators decided to compare mechanical ventilation based on driving
pressure with conventional mechanical ventilation in patients with lateral decubitus position
during total hip replacement surgery. The investigators hypothesised that, there will be
better intraoperative hemodynamic and respiratory parameters with better early postoperative
results in patients whom mechanical ventilation parameters are adjusted according to driving
pressure.
In this randomised, controlled, double blind study, 60 patients who will have total hip
replacement surgery will be recruited to the study. 30 patients will be ventilated by 8 ml/kg
tidal volume and 5 cmH20 PEEP, in conventional lung protective group. And the other 30
patients will be ventilated by 8 ml/kg tidal volume and PEEP level with the lowest driving
pressure.
The investigators primary goal in this study study is to compare the effects of conventional
lung protective ventilation with ventilation based on driving pressure on hemodynamic and
respiratory parameters. And secondly, the investigators aim to compare the effects of these
two techniques s on early postoperative outcome. The investigators primary result parameters
are intra operative fluid consumption, lactate, etC02 and mix venous oxygen saturation
levels.The investigators secondary result parameters are postoperative mechanical
ventilation, ICU stay and discharge times.
Description:
There may be physiologic and pathologic pulmonary changes because of inflammatory cytokine
release during total hip replacement surgery due to surgical invasivity or advanced age,
comorbidities, perioperative immobility of patients. Also intraoperative mechanical
ventilation can cause volutrauma, barotrauma or atelectrauma risk because of lateral position
during hip replacement surgery. All these factors can cause pulmonary complications and
vascular permeability increase in dependent and independent regions due to neutrophil
response increase. Intraoperative hypovolemia is often observed in this group patients
because of preoperative prolonged fasting periods, insufficient fluid intake due to
preoperative delirium and depression. Also mechanical ventilation with positive pressure
slightly decreases venous return to the heart resulting decrease in cardiac output. It is
more obvious in the presence of hypovolemia. Providing continuous sufficient intravascular
volume is necessary for prevention of tissue hypoxia and providing optimal cardiac output. It
is known that intra operative hemodynamic optimisation, has positive effects on mortality
ratio. But proper intravascular volume is not always easy to maintain, and it is not always
easy for anaesthetists to identify deficiency or overload of intra operative intravascular
volume. In recent years, intravascular volume therapies are goal directed by the reflections
of respiratory mechanics on arterial pressure and pulse oximetry. Plethysmographic wave
changes observed in pulse oximetry induced by positive pressure ventilation is accepted as
indicator of hypovolemia. Hemodynamic changes induced by respiratory mode can be measured by
invasive arterial monitorization. This dynamic variable is called as pulse pressure variation
index and is correlated with amplitude changes observed in pulse oximetry signals. These
variations are based on changes observed in pulse wavelength due to the changes in
intrathoracic pressure. In some pulse oximetry devices, this is done as standard function as
path variability index (PVI). PVI is measurement of dynamic changes of perfusion index during
a whole respiratory cycle. Pulse oximetry wave length changes enables the evaluate
hypovolemia noninvasively.
PVI is gaining importance as a dynamic parameter in evaluating fluid treatment during
surgery. Goal directed fluid therapy has shown positive effects on results on patient
survival. In a study which fluid therapy was guided by PVI changes and it was reported that,
goal directed fluid therapy had positive results.The investigators also, use some invasive
and noninvasive monitorization techniques, including PVI and CVP, to monitor static and
dynamic hemodynamic parameters during hip replacement surgery and we apply fluids according
to our fluid therapy protocols. The investigators use blood gas analysis to monitor the
efficiency of this treatment.
In this study, in both groups the investigators will apply fluid according to PVI values, so
if any difference detected is observed between groups will be because of the differences of
respiratory parameters between groups. And the investigators can detect, PVI stability and
less fluid needs differences between groups.
PETCO2 is, another parameter which will be evaluated in this study, is a factor of tissue CO2
production (VCO2), alveolar ventilation and cardiac output (mainly pulmonary blood flow). It
is known that, when CO2 produced at the tissues and formed in lungs are constant, the changes
of etCO2 are due to the blood flow differences and it is related to changes of cardiac
output. For this reason, PETCO2 is suggested as a noninvasive measure for continuous
assessment of cardiac output. At the same time, it is possible to comment about changes of
dead space by measuring arterial CO2 pressure.
Decrease of PETCO2, resulted from cardiac output decrease, can not be explained only with the
decrease rate of excretion of CO2, but also can be explained by the changes of production of
CO2 caused by dependency to oxygen supply. On the contrary, when cardiac output is high,
pulmonary blood flow is no longer a limiting factor for PETCO2 formation, and PETCO2 is
related to sufficiency of alveolar ventilation.
As a result, etCO2 measurement has some advantages; it is simple noninvasive and does not
require a invasive hemodynamic measurement.