ABSTRACT
<p><b>OBJECTIVE</b>To assess the possibility of using arterial pressure waveform or pulse oximetry plethysmographic waveform variation to estimate the pulmonary arterial wedge pressure (PAWP).</p><p><b>METHODS</b>Fourteen American Society of Anesthesiologists grade I - II patients aged 33 - 69 years and weighing 62.0 +/- 9.5 kg scheduled for elective abdominal tumor surgery were studied. Their hemoglobin exceeded 120 g/L and hematocrit exceeded 35 percent. Pre-operative acute hypervolemic hemodilution was applied immediately after general anesthestic induction and tracheal intubation. PAWP, systolic pressure variation (SPV), delta down (dDown), SPV(plet), dDown(plet) and other hemodynamic parameters were measured and recorded when total fluid volume (crystalloid and colloid) infused reached 10 ml/kg and 20 ml/kg and again at the end of the operation. Central venous pressure was maintained at 10 - 12 mm Hg during operation. Systolic blood pressure at the end of Valsalva maneuver (airway pressure was kept at 22 mm Hg) and the systolic pressure before the Valsalva manoeuvre during apnea were used to calculate arterial pressure ratio (APR).</p><p><b>RESULTS</b>APR, SPV, dDown, SPV(plet) and dDown(plet) all correlated well with PAWP (r = 0.717, -0.695, -0.680, -0.522 and -0.624 respectively, P < 0.01). There was a closer linear correlation between APR and PAWP than between the other parameters. The regression equation was PAWP (mm Hg) = 0.207 x APR (%) - 0.382.</p><p><b>CONCLUSION</b>During positive pressure mechanical ventilation, APR, SPV, dDown, SPV(plet) and dDown(plet) can be used to estimate PAWP effectively.</p>
Subject(s)
Adult , Aged , Humans , Middle Aged , Blood Pressure Determination , Methods , Oximetry , Plethysmography , Positive-Pressure Respiration , Pulmonary Wedge PressureABSTRACT
Objective To assess the possibility of using arterial pressure waveform or pulse oximetry plethysmographic waveform variation to estimate the pulmonary arterial wedge pressure (PAWP) Methods Fourteen ASA Ⅰ Ⅱ patients aged 33 69 years and weighing (62 0?9 5)kg scheduled for elective abdominal tumor surgery were studied Their Hb exceeded 120g/L and Hct 35% Anesthesia was induced with midazolam 0 04mg/kg atropine 8?g/kg,fentanyl 2?g/kg,propofol 2mg/kg and vecuronium 0 1mg/kg and maintained with isoflurane The patients were intubated and mechanically ventilated and P ET CO 2 was maintained at 4 67 5 33 kPa Radial artery was connulated for arterial pressure waveform monitoring and Swan Ganz catheter was inserted via right internal jugular vein and connected to continuous cardiac output monitor (VGS2,Baxter,USA) for hemodynamic monitoring Hypervolumic hemodilution was performed after induction of anesthesia and intubation with crystalloid and colloid (1:1) infused at a rate of 0 7ml?kg -1 ?min -1 PAWP, systolic pressure variation (SPV), delta down (dDown), SPV plet and dDown plet and other hemodynamic parameters were measured and recorded when total fluid volume (crystalloid and colloid) infused reached 10ml/kg and 20 ml/kg and at the end of operation, CVP was maintained at 10 12mm/kg during operation Systolic blood pressure at the end of Valsalva maneuver (airway pressure was kept at 30 cmH 2O) and the systolic pressure before the Valsalva maneuver during apnea were used to calculate arterial pressure ratio (APR) Results APR,SPV,dDown,SPV plet and dDown plet all correlated well with PAWP (r=o 7174,-0 6951,-0 680-0 5216 and 0 6237 respectively P
ABSTRACT
Objective To assess the feasibility of using plethysmographic waveform variation for estimating the blood volume.Methods After general anesthesia,tracheal intubation and 750ml liquid infusion,the systolic pressure variation(SPV),dDown(delta down),dUp(delta up),SPV plet,dDown plet,dUp plet,cardiac output and other hemodynamic parameters were recorded as control.Then,300ml of blood were drained quickly from radial artery into reservoir bag,and replaced with equal volume Gelofusine.The parameters were recorded again after blood drainage and volume replacement respectively.Results The changes in plethysmographic waveform correlated well with changes in arterial dDown(r==0804 ,P=0005)after acute loss of 300ml blood and dDown and dDown pletincreased from(459?294)mm Hg and (1024?532)% to (700?336)mm Hg and (1611?744)% respectively.Moreover,dDown,SPV plet and dDown pletvaried significantly(P