UTILIZACIÓN DE FACTORES DE CRECIMIENTO PARA LA DIFERENCIACIÓN

septic shock

D Sturgess1_{, R Pascoe}2_{, G Scalia}2_{, B Venkatesh}1 1_{University of Queensland, Brisbane, Australia;} 2_{The Wesley} Hospital, Brisbane, Australia

Critical Care2009, 13(Suppl 1):P200 (doi: 10.1186/cc7364) Introduction The plasma B-type natriuretic peptide concentration (BNP) appears not to predict fluid responsiveness in septic shock but no account has been made for the potential influence of cardiac rhythm [1]. Also, no comparison has been made between BNP and other clinical guides to fluid therapy, such as the Doppler aortic flow time corrected for heart rate (FTc) or central venous pressure (CVP). The aim of this preliminary study was to compare BNP, FTc and CVP as predictors of fluid responsiveness in septic shock patients without cardiac dysrhythmia.

Methods A prospective study of 10 consecutive adult septic shock patients (in sinus rhythm; 60% mechanically ventilated) treated with intravenous fluid challenge (4% albumin 250 ml over 15 min) in an Australian tertiary ICU. Results presented as the mean ± SD.

Results The APACHE II score was 21.8 ± 12.7. Haemodynamic assessment incorporating transcutaneous aortic Doppler (USCOM®₎ occurred before and 5 minutes after fluid challenge. Concurrent with the initial assessment, blood samples were collected for BNP assay (ADIVA Centaur®_{). Four patients demonstrated an increase} in stroke volume ≥15% (responders). Three of the responders had

an elevated baseline BNP (>144 pg/ml). The percentage change in stroke volume correlated with baseline FTc (r= –0.81;

P= 0.004) but not with BNP (r= –0.3; P= 0.4) or CVP (r= –0.4;

P= 0.2).

Conclusions Our data confirm that neither BNP nor CVP appear to predict fluid responsiveness. Furthermore, elevated BNP should not be viewed as a contraindication to fluid challenge in septic shock, as it does not exclude favourable haemodynamic response. Transcutaneous FTc offers promise as a predictor of fluid responsiveness and should be evaluated further.

Reference

1. Pirracchio R, et al.: Impaired plasma B-type natriuretic peptide clearance in human septic shock.Crit Care Med

2008, 36:2542-2546. P201

Intraoperative fluid optimization using stroke volume variation in high-risk surgical patients: preliminary results of a randomized prospective single-center study

J Beneš, I Chytra, P Altmann, M Hluchy, E Kasal, R Sviták, R Pradl, M Štepán

University Hospital, Plzen, Czech Republic

Critical Care2009, 13(Suppl 1):P201 (doi: 10.1186/cc7365) Introduction Stroke volume variation (SVV) is a good and easily obtained predictor of fluid responsiveness that can be used to guide fluid therapy in mechanically ventilated patients. During major abdominal surgery in patients with compromised cardiovascular reserves, inappropriate fluid management may result in occult organ hypoperfusion or in fluid overload and increased postoperative morbidity. The aim of our study was to evaluate the influence of SVV-guided fluid optimization on organ functions and postoperative morbidity and mortality in high-risk patients undergoing major abdominal surgery.

Methods Patients undergoing elective intraabdominal vascular and nonvascular surgery were randomly assigned to a control group with routine intraoperative care and a SVV group with fluid management guided by SVV derived from the Vigileo/FloTrac system. The intervention target was to maintain the SVV index below 10% with colloid boluses of 3 ml/kg. Postoperative ICU care was the same for both groups. Demographic parameters, comorbidities, performed surgical procedures, mortality and ICU and hospital lengths of stay were assessed. Laboratory parameters of organ hypoperfusion in the perioperative period (pH, base excess, serum lactate) and number of infectious and organ complications on day 7 and day 30 after operation were evaluated. The Mann–Whitney, unpaired t test and chi-squared test were used accordingly; P <0.05 was considered statistically significant. The study was approved by the local hospital ethic committee. Results A total of 80 patients were enrolled and randomized in the SVV (n = 40) and control (n = 40) groups. No significant differences between both groups in assessed parameters were found except for a difference in arterial pH (7.37 ± 0.05 vs. 7.35 ± 0.05; P = 0.04), lactate serum concentration at the end of the operation (median (IQR): 1.5 (1.2 to 1.9) mmol/l vs. 2.2 (1.39 to 2.35) mmol/l; P= 0.03) and the trend to lower rate of complications on day 30 in the SVV group (11 patients (39%) vs. 20 patients (57%); P = 0.06).

Conclusions Fluid optimization guided by SVV during major abdominal surgery decreases blood lactate at the end of operation and may be associated with a trend for a lower rate of post- operative organ complications.

Acknowledgement Supported by the research grant MSM0021620819.

Table 1 (abstract P199) Main results

Liberal, Goal, Restricted, PFR1 PFR3 PFR2 Age (years) 60 55 60 Surgery duration (hours) 6 6 5.5 Colloids (ml) 1,000 500 1,100 Crystalloids (ml) 4,600 2,200 1,450 Enteral nutrition (days from surgery) 4 4 3 Bowel movement (days from surgery) 3 4 3 Hospital length of stay (days) 11.5 11.5 9

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P202

Impedance cardiography in the estimation of

hemodynamic and fluid status of coma patients during continuous venovenous hemodiafiltration

A De Nicola, MJ Sucre

San Leonardo Hospital, Castellammare di Stabia, Italy Critical Care2009, 13(Suppl 1):P202 (doi: 10.1186/cc7366) Introduction Most ICU patients on continuous venovenous hemodiafiltration (CVVHDF) are in multisystem failure and require extensive monitoring [1]. Impedance cardiography (ICG) techno- logy provides a measurement of fluid status using the thoracic fluid content (TFC), along with cardiac output (CO), cardiac index (CI) and systemic vascular resistance index (SVRI). NICCOMO® (Medis, Germany), a noninvasive ICG device that provides trust- worthy measures, could be a complementary monitor for CVVHDF, supporting fluid balance and helping avoid hemodynamic instability [2].

Methods The study was an analysis of coma patients with acute renal failure while undergoing CVVHDF (Equasmart®_{; Hemodec,} Italy). By means of NICCOMO® _{the TFC, CI, CO, mean arterial} pressure and SVRI were constantly recorded. Employing the Pearson method, the percentage variations in each of the para- meters during the CVVHDF treatment were correlated to the amount of fluid removed (FR), normalized to body weight.

Results Ten patients were studied (six men and four women); the age range was 53.1 ± 15.2 years. A total of 16.6 l of fluid was removed during CVVHDF (830 ml/day over 20 treatment days). The median FR per day was 1,837 ml and the median hourly FR rate was 252 ml. TFC diminished in all patients at the end of CVVHDF treatment (average reduction 14.8 ± 9/kΩ), while all other hemodynamic parameters showed both increases and decreases. We found that the percentage TFC changes were closely and inversely related with those of FR (r= –0.68,

P<0.001); other hemodynamic parameters showed a moderate correlation with FR. The ICG device was helpful to promptly identify one patient who experienced hemodynamic instability and to prevent it.

Conclusions TFC is a reliable and noninvasive method for evaluating the quantity of FR during CVVHDF. This parameter changed consistently with fluid subtraction and TFC measurements can guide the extent of FR. This compact ICG device provides safe and accurate readings and seems to be one of the best options for evaluation of basic hemodynamic parameters and TFC during hemodiafiltration.

References

1. Vincent JL, et al.: Rev Med Brux2008, 29(1 Suppl):S9-S13. 2. Wynne L, et al.: J Surg Res2006, 133:55-60.

P203

Pulse and systolic pressure variation assessment in partially assisted ventilatory support

P Formenti, M Zaniboni, M Umbrello, A Galimberti, R Pinciroli, P Morelli, L Bolgiaghi, G Iapichino

Istituto di Anestesia e Rianimazione, Milan, Italy

Critical Care2009, 13(Suppl 1):P203 (doi: 10.1186/cc7367) Introduction The use of pulse pressure variation (PPV) and systolic pressure variation (SPV) is possible during controlled mechanical ventilation (MV) [1]. Even in acute respiratory failure, controlled MV tends to be replaced by assisted ventilatory support, which may generate a tidal volume (Tv) inadequate to change the pulmonary venous flow and swing in pleural pressure [2]. This

makes the use of dynamic indices unreliable. Our hypothesis was that during a pressure-support-assisted ventilatory (PSV) approach few imposed breaths (flow-triggered synchronized intermittent mechanical ventilation (SIMV)) could allow the monitoring of PPV and SPV. We therefore tested whether PPV and SPV during PSV + SIMV could be as accurate as in controlled MV.

Methods A prospective case–control study. Thirty patients who met the criteria of weaning from controlled MV were included. PPV and SPV were measured, first, during 20 minutes in PSV with three per minute flow-triggered SIMV breaths (10 ml/kg, duration 5 s, inspiration to expiration ratio 1:3) (T1), and then during three consecutive breaths in controlled MV (respiratory rate 12/min, duration 5 s, inspiration to expiration ratio 1:3, Tv 10 ml/kg, positive end-expiratory pressure and FiO₂ as in PSV) (T2). Throughout 20 minutes of data collection, saline infusions were kept constant (3 ml/hour) without performing any fluid loading. Correlation and Bland–Altman analysis were used to compare respective values of PPV and SPV in the two modes of ventilation.

Results Significant correlations were found between dynamic indices in SIMV during pressure support ventilation and those in controlled MV mode. The mean differences between two measurements were: PPV 0.6 ± 2.8% (limit of agreement: –5.0 and 6.2), SPV 0.5 ± 2.3 mmHg (limit of agreement: –4.0 and 5.1). Conclusions PPV and SPV measured during SIMV fitted with the findings in controlled MV. Dynamic indexes could be accurately monitored in patients breathing with assisted respiratory assistance adding an imposed large enough SIMV breath [3]. References

1. De Backer D, et al.: Can one predict fluid responsiveness in spontaneously breathing patients? Intensive Care Med

2007, 33:1111-1113.

2. Heenen S, et al.: How can the response to volume expan- sion in patients with spontaneous respiratory movements be predicted? Crit Care2006, 10:R102.

3. Zaniboni M, et al.: Pulse and systolic pressure variation assessment in partially assisted ventilatory support. J Clin Monit Comput2008, 22:355-359.

P204

Does the pleth variability index improve fluid management during major abdominal surgery?

P Forget, F Lois, M De Kock

St-Luc Hospital, Université Catholique de Louvain, Brussels, Belgium

Critical Care2009, 13(Suppl 1):P204 (doi: 10.1186/cc7368) Introduction Dynamic parameters predict fluid responsiveness and improve fluid management during surgery. We intend to demonstrate that the noninvasive pleth variability index (PVI) guides peroperative fluid management and optimizes the circulatory status.

Methods Patients scheduled for major abdominal surgery were randomized into two groups comparing the peroperative PVI- directed fluid management (group P) versus standard care (control, group C). Protocol: induction of general anesthesia was followed by, in group P, 500 ml followed by 2 ml/kg/hour crystalloids; 250 ml colloids infused if PVI >13% for more than 5 minutes; if required, vasoactive support was introduced after lowering PVI <10%. In group C, 500 ml crystalloids followed by fluids at the discretion of the anesthesiologist.

Results Eighty-two patients completed the protocol. No difference was detected in preoperative characteristics, type of surgery and anesthesia. Peroperative and postoperative (24-hour) crystalloid infusions were significantly different. Lactate levels were

S83 significantly lower in group P, whereas the peroperative and post-

operative volumes infused in group P were lower (Figure 1). Conclusions The PVI improves peroperative fluid management in abdominal surgery. The reduced mean volume infused associated with reduced lactate levels suggests the capacity of the PVI to infer tailored fluid administration.

P205

Plethysmography variability index: a new fluid responsiveness parameter

M Feissel1_{, R Kalakhy}1_{, J Badie}1_{, G Robles}1_{, J Faller}1_,

JL Teboul2

1_{CHBM, Belfort, France;} 2_{APHP, Le Kremlin Bicetre, France} Critical Care2009, 13(Suppl 1):P205 (doi: 10.1186/cc7369) Introduction New predictors of fluid responsiveness have been obtained from plethysmographic waveforms displayed on pulse oxymeters. However, they require recordings on a PC and offline operator-dependent analysis. A new parameter called the plethysmography variability index (PVI) has been proposed by a pulse oxymetry manufacturer to be used for the purpose of fluid responsiveness. Its advantage is that it can be automatically calculated and displayed on the screen of the pulse oxymetry monitor. The aim of the study is to test the accuracy of this parameter to predict fluid responsiveness in critically ill patients. Methods Inclusion criteria were septic shock patients fully adapted to their respirator and on sinus rhythm. Methods involved simultaneous recording of the following tracings: invasive blood pressure, plethysmography pulse oxymeter (Philips™), ECG, airway pressure and digit values inscribed on the device (Masimo™). Echocardiography was used to calculate the velocity–time integral (VTI). We infused fluid (500 ml saline) in patients with pulse pressure variation (ΔPP) ≥15% and performed passive leg raising (PLR) in patients with ΔPP <15%. We compared the PVI with ΔPP and with the variability of pulse oxymeter wave amplitude (ΔPPleth) and sought the best threshold PVI value that predicted ΔPP >15%. Patients who increased their VTI by more than 15% in response to fluid or to PLR were defined as responders. The significance of the PVI threshold to distinguish between responders and nonresponders was examined.

Results In the first step 25 patients were enrolled. Fifty paired values were analysed. The r2 _{coefficients between ΔPP–PVI,} ΔPPleth–PVI and ΔPP–ΔPPleth were 0.81, 0.79 and 0.74, respectively. A threshold PVI value of 20 identified patients with ΔPP >15% with a sensitivity of 84% and specificity of 90%. In a second step 18 other patients were enrolled. All patients with PVI >20 (n= 8) were fluid responders and 10 patients with PVI <20 were PLR nonresponders.

Conclusions The PVI automatically obtained from a pulse oxymetry device seems an accurate index of fluid responsiveness. The numerical value of 20 distinguished responders from non- responders with good sensitivity and specificity.

P206

Calibration of pulse contour continuous cardiac output analysis

L Weng, B Du, XY Hu, JM Peng

Peking Union Medical College Hospital, Beijing, China Critical Care2009, 13(Suppl 1):P206 (doi: 10.1186/cc7370) Introduction We evaluated the effect of the calibration interval on the reliability of pulse contour cardiac output (COpc) measurement [1].

Methods Eleven patients were investigated for over 10 hours using two COpc monitors simultaneously. One COpc (COpcCAL) monitor was calibrated hourly, while the other (COpcNOCAL) was calibrated once initially without any further calibration. COpcCAL was compared with COpcNOCAL.

Results A total of 116 pairs of cardiac output measurement was obtained. After 3 hours, the correlation between COpcCAL and COpcNOCAL was r2_{= 0.85, P <0.0001, bias ± SD was –0.43 ±} 0.87 ml/minute; after 6 hours, r2_{= 0.68, P = 0.0064, bias ± SD} was –0.83 ± 1.39 ml/minute; after 10 hours, r2_{= 0.70, P= 0.0026,} bias ± SD was –0.81 ± 1.21 ml/minute. See Figures 1 and 2. Conclusions The calibration interval has no effect on the reliability of the COpc measurement.

Reference

1. Gödje O, et al.: Reliability of a new algorithm for continu- ous cardiac output determination by pulse-contour analy- sis during hemodynamic instability. Crit Care Med 2002, 30:52-58.

P207

Is the pulse pressure variation a good predictor of fluid responsiveness in mechanically ventilated patients with low tidal volume?

C Costa, S Vieira, G Friedman, L Fialkow

Hospital de Clinicas de Porto Algre, Brazil

Critical Care2009, 13(Suppl 1):P207 (doi: 10.1186/cc7371) Introduction Dynamic preload indicators are superior to static indicators for predicting fluid responsiveness [1-3]. The aim of this study is to evaluate the influence of a low tidal volume on the capacity of pulse pressure variation (PPV) to predict fluid responsiveness.

Methods A transversal and interventional study that included 30 critically ill patients with acute circulatory failure, sedated and mechanically ventilated with a tidal volume of 6 to 7 ml/kg. Mechanical ventilatory measurements including positive end- expiratory pressure plateau and peak pressures, static compliance and hemodynamic measurements including PPV, heart rate, mean systemic and pulmonary arterial pressures, central venous pressure, pulmonary capillary wedge pressure and cardiac index were obtained before and after fluid challenge, performed with 1,000 ml crystalloids or 500 ml colloids. Fluid responsiveness was defined as an increase in cardiac index of at least 15%.

Results Thirty patients were enrolled: aged 56 ± 16.8 years, APACHE score = 28 ± 8, male = 15; 19 patients with septic shock, one patient with sepsis, five patients in postoperative liver transplantation, three patients with acute pancreatitis, one patient with cardiogenic shock and one patient in postoperative aortic

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aneurysm. Before fluid challenge: total positive end-expiratory pressure = 09 ± 3.7 cmH₂O, static compliance = 34.3 ± 16.3 cmH₂O, pulmonary capillary wedge pressure = 13.8 ± 5 mmHg, central venous pressure = 11.6 ± 5 mmHg. Fourteen patients were fluid responders (Figure 1). The best threshold value of PPV was 10% (receiver operating characteristic curve area = 0.7, 95% CI = 0.51 to 0.9), sensibility of 50%, specificity of 94%, a

positive predictive value of 88%, a negative predictive value of 68%, a positive likelihood ratio of 8.0 and a negative likelihood ratio of 0.53.

Conclusions The baseline PPV is a good predictor of fluid responsiveness in mechanically ventilated patients with low tidal volume. The threshold value of 10% was associated with a significant increase in cardiac index after volume expansion.

Figure 2 (abstract P206)

Bland–Altman plot of COpcCAL and COpcNOCAL. Solid line, bias; dashed lines, ± 2SD.

Figure 1 (abstract P206)

S85 References

1. Teboul JL: Relation between respiratory changes in arterial pulse pressure and fluid responsiveness in septic patients with acute circulatory failure.Am J Respir Crit Care Med

2000, 162:134-138.

2. De Backer D: Pulse pressure variations to predict fluid responsiveness: influence of tidal volume. Intensive Care Med2005, 31:517-523.

3. Chung-Chi H: Prediction of fluid resposiveness in acute respiratory distress syndrome patients ventilated with low tidal volume and high positive end-expiratory pressure.

Crit Care Med2008, 36:2810.

P208

Proving the effectiveness of three dynamic indices to predict fluid responsiveness in septic mechanically ventilated patients

P Wacharasint, A Lertamornpong, A Wathanathum, A Wongsa

Phramongkutklao Hospital, Bangkok, Thailand

Critical Care2009, 13(Suppl 1):P208 (doi: 10.1186/cc7372) Introduction Fluid responsiveness is still a cornerstone in managing patients with severe sepsis and septic shock. Recently new technologies have been generated for facilitating the accuracy of predicting fluid responsiveness at the bedside, based on cardiopulmonary interaction [1,2]. We evaluated the effectiveness and accuracy of three dynamic indices, currently available in intensive care monitoring devices, which are pulse pressure variation (PPV) [3], stroke volume variation (SVV) and pulse oximetry plethysmographic waveform variation (POPV) in septic mechanically ventilated patients [4].

Methods A prospective clinical trial was conducted in 20 septic patients 18 years of age and older who had invasive blood pressure monitoring with an intraarterial cannula. PPV, SVV and POPV (%) were calculated and compared with the percentage cardiac index (CI) change. Patients with a CI increase induced by volume expansion >15% were classified as responders, and <15% as nonresponders. A parametric paired ttest was used to compare hemodynamic parameters at baseline and after volume expansion. Student’s t test was used to compare hemodynamic parameters in the responders and nonresponders groups. Receiver operating characteristic curves were used to evaluate the

predictive value of various indices on fluid responsiveness.

P<0.05 was considered significant.

Results We found a strong correlation existed for PPV for detection of a volume expansion-induced change in CI (r2 ₌ 0.794), followed by SVV (r2_{= 0.667), and POPV (r}2_{= 0.633). The} areas under the receiver operating characteristic curves were 0.96 for PPV (P<0.001), 0.92 for SVV (P= 0.001), and 0.85 for POPV (P= 0.008). Respiratory variation in POPV exceeding 14% (sensi- tivity of 72%, specificity of 90%), SVV exceeding 11% (sensitivity 90%, specificity 92%), allowed detection of PPV exceeding 12% (sensitivity 84%, specificity 96%).

Conclusions In the septic mechanically ventilated patients, PPV is the most effective dynamic parameter for predicting fluid responsiveness; all of PPV, SVV and POPV are well correlated with the percentage change of CI.

References

1. Michard F, Teboul JL: Predicting fluid responsiveness in ICU patients: a critical analysis of the evidence. Chest

2002, 121:2000-2008.

2. Bendjelid K, Romand JA: Fluid responsiveness in mechani- cally ventilated patients: a review of indices used in inten- sive care. Intensive Care Med2003, 29:352-360.

3. Michard F, et al.: Relation between respiratory changes in arterial pulse pressure and fluid responsiveness in septic patients with acute circulatory failure. Am J Respir Crit Care Med2000, 162:134-138.

4. Feissel M, et al.: Plethysmographic dynamic indices predict fluid responsiveness in septic ventilated patients. Intensive Care Med2007, 33:993-999.

P209

Cross-comparison of the trending accuracy of continuous cardiac output measurement devices in postoperation patients

HK Kim, M Hadian, D Severyn, MR Pinsky

University of Pittsburgh Medical Center, Pittsburgh, PA, USA Critical Care2009, 13(Suppl 1):P209 (doi: 10.1186/cc7373) Introduction Arterial pulse analysis estimates of cardiac output (CO) are less invasive than pulmonary artery catheter (PAC)- derived ones. Although PAC bolus thermodilution CO (COtd) values are the reference CO values for most clinical studies, there is no defined gold standard. We therefore compared the co- variance of three commercially available arterial pulse analysis

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