Anesthetized Ventilated Patients Clinical Trial
Official title:
Pulse Transit Time in Anesthetized Ventilated Patients: Affect of Blood Pressure or Cardiac Output as Measured With NICOM Monitor
Pulse transit time (PuTT) - the time between R wave on ECG and initiation of upstroke in the peripheral arterial waveform - described in the previous studies as value that reflects changes in both blood pressure and blood volume. The investigators are assuming that PuTT changes reflect the dynamic of systolic blood pressure but not cardiac output fluctuations.
Background Pulse transit time (PuTT) - the time between R wave on ECG and initiation of
upstroke in the peripheral arterial waveform - described in the previous studies as value
that reflects changes in both blood pressure and blood volume. We are assuming that PuTT
changes reflect the dynamic of systolic blood pressure but not cardiac output fluctuations.
Clinical trial objectives Investigate a link between PuTT (Pulse transit time) and changes
in blood pressure and cardiac output measured by non-invasive cardiac output monitoring
device (NICOM).
Endpoints PuTT Blood pressure: systolic, diastolic, mean Heart rate Cardiac output-Index
Systemic vascular resistance-Index
Prospective nonrandomized clinical trial
Inclusion criteria Need for continuous invasive monitoring of blood pressure - according to
the type of surgery the patient's health status Normal sinus rhythm
Exclusion criteria Pregnancy Cave to Nitroglycerine or Phenylephrine Chronic renal failure
with creatinine level above 2 mg%
Safety assessment methods Monitoring of cardiac output is one of the most important elements
of hemodynamic monitoring. In the past this monitoring was based mainly on the invasive and
awkward methods causing usage only in exceptional cases. NICOM device allows accurate
non-invasive monitoring of cardiac output During anesthesia patient care changes are made
according to changes in vital indicators such as blood pressure, pulse, cardiac output. So
during the study, anesthesia care can be affected by the indices obtained using a NICOM.
Data processing and analysis During the surgery the continuous monitoring of blood pressure
by peripheral artery catheter and cardiac output by NICOM will be applied.
In case of hemodynamic changes the patient will be treated according to the standard care:
In case of decrease of systolic blood pressure below 80 mmHg (in the patients with history
of arterial hypertension - below 90 mmHg) and HR is above 70 bpm the patient will be treated
by repeated boluses of Phenylephrine 50-100 mcg until the systolic blood pressure will
increase by at least 20%.
Intraoperative hypertension above 160 mmHg will be treated by repeated boluses of
Nitroglycerine 100 mcg until the systolic blood pressure will decrease by at least 20%.
Hypovolemia will be treated by boluses of colloid solution - HAES 6% - at dose of 7 ml/kg of
body mass during 15 min.
Study procedures
Cardiac output will be measured by NICOM just before and after each treatment of hemodynamic
events that described above. Simultaneous records of ECG, arterial and plethysmographic
waveforms will be made just before and after each event.
Systolic blood pressure and PuTT will be measured OFFLINE from the recorded waveforms.
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Observational Model: Cohort, Time Perspective: Prospective