The use of central venous pressure has been abandoned for the assessment of intravascular volume status. The dynamic fluctuation of central venous pressure according to heart rate is quantitatively measured by spectral analysis of the central venous pressure waveform. Its clinical utility in the assessment of intravascular volume status is investigated.
The use of central venous pressure, which is one of the static preload indices, has been abandoned for the assessment of intravascular volume status because of its unreliability. The static preload indices have been replaced with dynamic preload indices, such as stroke volume variation or pulse pressure variation because the dynamic preload indices reliably predict fluid responsiveness and perform better than the static preload indices. However, the periodic component of central venous pressure, which goes with cardiac cycles, has not been investigated. The power corresponding to heart rate from spectral analysis of central venous pressure waveform represents the extent of the dynamic fluctuation of central venous pressure and is assumed to reflect intravascular volume status. It is hypothesized that the spectral power of central venous pressure corresponding to heart rate represents intravascular volume status.
Study Type
OBSERVATIONAL
Enrollment
60
The right internal jugular vein is located at the first rib level under ultrasound-guidance. Using an out-of-plane technique, a needle is introduced into the lumen of the vessel. The aspiration of blood into the syringe connected to the hub of the needle confirms the placement of the needle tip in the lumen. After the syringe is detached from the needle, a guidewire is advanced into the vessel lumen through the needle. A dilator is introduced over the guidewire and subsequently is removed. Then, a central venous catheter is introduced over the guidewire into the vessel lumen through the pathway expanded by the dilator. The catheter tip is placed in the superior vena cava by inserting the catheter as far as the distance between the edge of the right transverse process of the first thoracic vertebra and the carina, which is preoperatively measured on a posteroanterior chest radiograph.
Following the placement of a central venous catheter, a fluid-filled system for monitoring central venous pressure is connected to the proximal lumen of the catheter. The reference transducer is placed at the level of 4/5 of the anteroposterior diameter of the thorax.
Daegu Catholic University Medical Center
Daegu, South Korea
Spectral power of central venous pressure corresponding to heart rate during 5 minutes before graft procurement
A band-pass filter (0.15-3 Hz) is applied to the 5 minute-long segment. The 5 minute-long segments are divided into 100 second-long segments overlapping 50% with each adjacent segment. Each segment is submitted to fast Fourier transformation. The spectral powers obtained from the periodograms of each segment are averaged. The integrated area corresponding to heart rate is the spectral power corresponding to heart rate.
Time frame: During 5 minutes before graft procurement
Spectral powers of central venous pressure corresponding to respiratory rate and heart rate during 5 minutes before the first dose of furosemide
A band-pass filter (0.15-3 Hz) is applied to the 5 minute-long segment. The 5 minute-long segments are divided into 100 second-long segments overlapping 50% with each adjacent segment. Each segment is submitted to fast Fourier transformation. The spectral powers obtained from the periodograms of each segment are averaged. The integrated areas corresponding to respiratory rate and heart rate are the spectral powers corresponding to respiratory rate and heart rate.
Time frame: During 5 minutes before the first dose of furosemide
Spectral powers of central venous pressure corresponding to respiratory rate and heart rate between 30 and 35 minutes after surgical incision
A band-pass filter (0.15-3 Hz) is applied to the 5 minute-long segment. The 5 minute-long segments are divided into 100 second-long segments overlapping 50% with each adjacent segment. Each segment is submitted to fast Fourier transformation. The spectral powers obtained from the periodograms of each segment are averaged. The integrated areas corresponding to respiratory rate and heart rate are the spectral powers corresponding to respiratory rate and heart rate.
Time frame: Between 30 and 35 minutes after surgical incision
Spectral power of central venous pressure corresponding to respiratory rate during 5 minutes before graft procurement
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Patients fast from 10 pm the day before surgery. On the arrival at the operating room, an intravenous catheter for Plasmalyte infusion is placed into the right cephalic or basilic vein. The distal lumen of the central venous catheter is used for the infusion of 6% hydroxyethyl starch. Fluid requirements due to anesthesia, surgery, and no per os intake are not replaced by minimizing the administration of the fluids. Five minutes after the collection of the baseline data, 20 mg of furosemide is administered to promote diuresis for facilitating the venous outflow of the liver. An additional dose of furosemide 20 mg is given if the urine output is \<1 ml/kg within 30 minutes after the first dose. Unless the second dose of furosemide produces \>1 ml/kg of urine within 30 minutes, 40 mg of furosemide is administered. In the absence of effective diuresis (1 ml/kg within 30 minutes after each dose), the use of furosemide is abandoned and the patients are excluded from the study.
Immediately after the graft procurement, 500 ml of 6% hydroxyethyl starch are infused over 25 minutes. Afterward, Plasmalyte is infused at a rate of 10 ml/min until the end of surgery.
Following anesthesia induction, the right radial artery is catheterized. The catheter is connected to the EV1000 monitor (Edwards Lifesciences, Irvine, CA) through the FloTrac transducer (Edwards Lifesciences). The transducer is level with the one for central venous pressure monitoring. Using pulse contour analysis without external calibration, the stroke volume for each heartbeat is measured. At a 20-second interval, stroke volume variation is calculated as (maximum stroke volume - minimum stroke volume)/mean stroke volume.
A band-pass filter (0.15-3 Hz) is applied to the 5 minute-long segment. The 5 minute-long segments are divided into 100 second-long segments overlapping 50% with each adjacent segment. Each segment is submitted to fast Fourier transformation. The spectral powers obtained from the periodograms of each segment are averaged. The integrated area corresponding to respiratory rate is the spectral power corresponding to respiratory rate.
Time frame: During 5 minutes before graft procurement
Spectral powers of central venous pressure corresponding to respiratory rate and heart rate during 5 minutes after administration of 6% hydroxyethyl starch
A band-pass filter (0.15-3 Hz) is applied to the 5 minute-long segment. The 5 minute-long segments are divided into 100 second-long segments overlapping 50% with each adjacent segment. Each segment is submitted to fast Fourier transformation. The spectral powers obtained from the periodograms of each segment are averaged. The integrated areas corresponding to respiratory rate and heart rate are the spectral powers corresponding to respiratory rate and heart rate.
Time frame: During 5 minutes after administration of 6% hydroxyethyl starch
Stroke volume variation during 5 minutes before the first dose of furosemide
The median of the values calculated at a 20-second interval
Time frame: During 5 minutes before the first dose of furosemide
Stroke volume index during 5 minutes before the first dose of furosemide
The median of the values calculated at a 20-second interval
Time frame: During 5 minutes before the first dose of furosemide
Cardiac index during 5 minutes before the first dose of furosemide
The median of the values calculated at a 20-second interval
Time frame: During 5 minutes before the first dose of furosemide
Stroke volume variation between 30 and 35 minutes after surgical incision
The median of the values calculated at a 20-second interval
Time frame: Between 30 and 35 minutes after surgical incision
Stroke volume index between 30 and 35 minutes after surgical incision
The median of the values calculated at a 20-second interval
Time frame: Between 30 and 35 minutes after surgical incision
Cardiac index between 30 and 35 minutes after surgical incision
The median of the values calculated at a 20-second interval
Time frame: Between 30 and 35 minutes after surgical incision
Stroke volume variation during 5 minutes before graft procurement
The median of the values calculated at a 20-second interval
Time frame: During 5 minutes before graft procurement
Stroke volume index during 5 minutes before graft procurement
The median of the values calculated at a 20-second interval
Time frame: During 5 minutes before graft procurement
Cardiac index during 5 minutes before graft procurement
The median of the values calculated at a 20-second interval
Time frame: During 5 minutes before graft procurement
Stroke volume variation during 5 minutes after administration of 6% hydroxyethyl starch
The median of the values calculated at a 20-second interval
Time frame: During 5 minutes after administration of 6% hydroxyethyl starch
Stroke volume index during 5 minutes after administration of 6% hydroxyethyl starch
The median of the values calculated at a 20-second interval
Time frame: During 5 minutes after administration of 6% hydroxyethyl starch
Cardiac index during 5 minutes after administration of 6% hydroxyethyl starch
The median of the values calculated at a 20-second interval
Time frame: During 5 minutes after administration of 6% hydroxyethyl starch
Total dose of furosemide
The total dose of furosemide used for the promotion of diuresis
Time frame: At graft procurement
Urine output at graft procurement
The total amount of urine output between the placement of urinary catheter and graft procurement
Time frame: At graft procurement
Total urine output at the end of surgery
The total amount of urine output at the end of surgery
Time frame: At the end of surgery
Intraoperative blood loss
Calculated as blood loss (ml) = \[estimated blood volume\*(preoperative hematocrit-postoperative hematocrit)\]/mean between the 2 hematocrit values, where estimated blood volume (ml) = weight(kg)\^0.425\*height(cm)\^0.725\*0.007184\*2217+age(years)\*1.06 for female and weight(kg)\^0.425\*height(cm)\^0.725\*0.007184\*3064-825 for male
Time frame: 1 day after surgery