Prevalence, characteristics, and outcomes of patients presenting with cardiogenic unilateral pulmonary edema.

BACKGROUND: Cardiogenic unilateral pulmonary edema (UPE) is a rare entity, frequently leading to initial misdiagnosis. We sought to assess the prevalence of UPE and to determine its impact on prognosis compared with bilateral pulmonary edema. METHODS AND RESULTS: We studied the characteristics and outcomes of patients admitted to our institution for cardiogenic pulmonary edema during an 8-year period. The study population included 869 consecutive patients. The prevalence of UPE was 2.1%: 16 right-sided UPE (89%) and 2 left-sided UPE (11%). In patients with UPE, blood pressure was significantly lower (P≤0.01), whereas noninvasive or invasive ventilation and catecholamines were used more frequently (P=0.0004 and P<0.0001, respectively). The prevalence of severe mitral regurgitation in patients with bilateral pulmonary edema and UPE was 6% and 100%, respectively (P<0.0001). In patients with UPE, use of antibiotic therapy and delay in treatment were significantly higher (P<0.0001 and P=0.003, respectively). In-hospital mortality was 9%: 39% for UPE versus 8% for bilateral pulmonary edema (odds ratio, 6.9; 95% confidence interval, 2.6 to 18; P<0.001). In multivariate analysis, unilateral location of pulmonary edema was independently related to death whatever the model used (adjusted odds ratio, 6.5; 95% confidence interval, 1.3 to 32; P=0.021 for model A; and adjusted odds ratio, 6.8; 95% confidence interval, 1.1 to 41; P=0.037 for model B). CONCLUSIONS: Unilateral pulmonary edema represented 2.1% of cardiogenic pulmonary edema in our study, usually appeared as an opacity involving the right lung, and was always associated with severe mitral regurgitation. Unilateral pulmonary edema is related to an independent increased risk of mortality and should be promptly recognized to avoid delays in treatment.

Computed tomography for the detection of free-floating thrombi in the right heart in acute pulmonary embolism.

OBJECTIVES: The aim of this study was to assess the prevalence of free-floating thrombi in the right heart (FFT) and the accuracy of computed tomography (CT) for their detection in pulmonary embolism (PE). METHODS: We studied 340 consecutive patients presenting with PE. All patients underwent CT and echocardiography. RESULTS: The prevalence of FFT was 3.5% in the global population of PE and 22% in high-risk PE. Dyspnoea, cardiogenic shock, cardiac arrest and tachycardia were more frequently found in patients with FFT (p = 0.04, p < 0.0001, p = 0.0003 and p = 0.01, respectively). Sensitivity and specificity of CT for the detection of FFT were 100% (95% confidence interval: 74%-100%) and 97% (95%-99%), whereas positive and negative predictive values were 57% (34%-78%) and 100% (99%-100%). Among patients with FFT, right ventricular dilation was always detected by CT, whereas no right ventricular dilation was found among patients with a false diagnosis of FFT performed by CT (p < 0.0001). CONCLUSION: Prevalence of FFT is 3.5% and differs according to the clinical presentation. Detection of FFT by CT is feasible and should lead to echocardiography being promptly performed for the confirmation of FFT.

PaCO2 and alveolar dead space are more relevant than PaO2/FiO2 ratio in monitoring the respiratory response to prone position in ARDS patients: a physiological study.

INTRODUCTION: Our aims in this study were to report changes in the ratio of alveolar dead space to tidal volume (VDalv/VT) in the prone position (PP) and to test whether changes in partial pressure of arterial CO2 (PaCO2) may be more relevant than changes in the ratio of partial pressure of arterial O2 to fraction of inspired O2 (PaO2/FiO2) in defining the respiratory response to PP. We also aimed to validate a recently proposed method of estimation of the physiological dead space (VDphysiol/VT) without measurement of expired CO2. METHODS: Thirteen patients with a PaO2/FiO2 ratio < 100 mmHg were included in the study. Plateau pressure (Pplat), positive end-expiratory pressure (PEEP), blood gas analysis and expiratory CO2 were recorded with patients in the supine position and after 3, 6, 9, 12 and 15 hours in the PP. Responders to PP were defined after 15 hours of PP either by an increase in PaO2/FiO2 ratio > 20 mmHg or by a decrease in PaCO2 > 2 mmHg. Estimated and measured VDphysiol/VT ratios were compared. RESULTS: PP induced a decrease in Pplat, PaCO2 and VDalv/VT ratio and increases in PaO2/FiO2 ratios and compliance of the respiratory system (Crs). Maximal changes were observed after six to nine hours. Changes in VDalv/VT were correlated with changes in Crs, but not with changes in PaO2/FiO2 ratios. When the response was defined by PaO2/FiO2 ratio, no significant differences in Pplat, PaCO2 or VDalv/VT alterations between responders (n = 7) and nonresponders (n = 6) were observed. When the response was defined by PaCO2, four patients were differently classified, and responders (n = 7) had a greater decrease in VDalv/VT ratio and in Pplat and a greater increase in PaO2/FiO2 ratio and in Crs than nonresponders (n = 6). Estimated VDphysiol/VT ratios significantly underestimated measured VDphysiol/VT ratios (concordance correlation coefficient 0.19 (interquartile ranges 0.091 to 0.28)), whereas changes during PP were more reliable (concordance correlation coefficient 0.51 (0.32 to 0.66)). CONCLUSIONS: PP induced a decrease in VDalv/VT ratio and an improvement in respiratory mechanics. The respiratory response to PP appeared more relevant when PaCO2 rather than the PaO2/FiO2 ratio was used. Estimated VDphysiol/VT ratios systematically underestimated measured VDphysiol/VT ratios.

Acute cor pulmonale.

PURPOSE OF REVIEW: Acute cor pulmonale is a form of acute right heart failure produced by a sudden increase in resistance to blood flow in the pulmonary circulation, which is now rapidly recognized by bedside echocardiography. RECENT FINDINGS: In the clinical setting, acute cor pulmonale is mainly observed as a complication of massive pulmonary embolism or acute respiratory distress syndrome. In acute respiratory distress syndrome, the worsening effect of mechanical ventilation has been recently emphasized. SUMMARY: As a general rule, the treatment consists in rapidly reducing resistance to blood flow in the pulmonary circulation, obtained by a specific strategy according to etiology.

Actual incidence of global left ventricular hypokinesia in adult septic shock.

RATIONALE AND OBJECTIVE: To evaluate the actual incidence of global left ventricular hypokinesia in septic shock. METHOD: All mechanically ventilated patients treated for an episode of septic shock in our unit were studied by transesophageal echocardiography, at least once a day, during the first 3 days of hemodynamic support. In patients who recovered, echocardiography was repeated after weaning from vasoactive agents. Main measurements were obtained from the software of the apparatus. Global left ventricular hypokinesia was defined as a left ventricular ejection fraction of <45%. MEASUREMENTS AND MAIN RESULTS: During a 3-yr period (January 2004 through December 2006), 67 patients free from previous cardiac disease, and who survived for >48 hrs, were repeatedly studied. Global left ventricular hypokinesia was observed in 26 of these 67 patients at admission (primary hypokinesia) and in 14 after 24 or 48 hrs of hemodynamic support by norepinephrine (secondary hypokinesia), leading to an overall hypokinesia rate of 60%. Left ventricular hypokinesia was partially corrected by dobutamine, added to a reduced dosage of norepinephrine, or by epinephrine. This reversible acute left ventricular dysfunction was not associated with a worse prognosis. CONCLUSION: Global left ventricular hypokinesia is very frequent in adult septic shock and could be unmasked, in some patients, by norepinephrine treatment. Left ventricular hypokinesia is usually corrected by addition of an inotropic agent to the hemodynamic support.

Hemodynamic effects of passive leg raising: an echocardiographic study in patients with shock.

OBJECTIVES: To determine the effects of passive leg raising (PLR) on hemodynamics and on cardiac function according to the preload dependency defined by the superior vena cava collapsibility index (DeltaSVC). RESULTS: Forty patients with shock, sedated and mechanically ventilated, were included. Transesophageal echocardiography was performed. At baseline (T1), two groups were defined according to DeltaSVC. Eighteen patients presenting a DeltaSVC > 36%, an indicator of preload dependency, formed group 1, whereas 22 patients (group 2) exhibited a DeltaSVC < 30% (not preload-dependent). Measurements were then performed during PLR (T2), back to baseline (T3), and after volume expansion (T4) in group 1 only. At T1, DeltaSVC was significantly higher in group 1 than in group 2, 50 +/- 9% and 7 +/- 6%, respectively. In group 1, we found a decrease in DeltaSVC at T2 (24 +/- 9%) and T4 (17 +/- 7%), associated with increased systolic, diastolic and arterial pulse pressures. Cardiac index also increased, from 1.92 +/- 0.74 (T1) to 2.35 +/- 0.92 (T2) and 2.85 +/- 1.2 l/min/m(2) (T4) and left ventricular end-diastolic volume from 51 +/- 41 to 61 +/- 51 and 73 +/- 51 ml/m(2). None of these variations was found in group 2. No change in heart rate was observed. CONCLUSION: Hemodynamic changes related to PLR were only induced by increased cardiac preload.

Prone positioning unloads the right ventricle in severe ARDS.

BACKGROUND: Despite airway pressure limitation, acute cor pulmonale persists in a minority of ARDS patients. Insufficient airway pressure limitation, hypercapnia, or both may be responsible. Because prone positioning (PP) has been shown to be a safe way to reduce airway pressure and to improve alveolar ventilation, we decided to assess its effect on right ventricular (RV) pressure overload in ARDS patients. METHODS: Between January 1998 and December 2006, we studied 42 ARDS patients treated by PP to correct severe oxygenation impairment (Pao2/fraction of inspired oxygen ratio, <100 mm Hg). RV function was evaluated by bedside transesophageal echocardiography, before and after 18 h of prone-position ventilation. RV enlargement was measured by RV/left ventricular (LV) end-diastolic area ratio in the long axis. Septal dyskinesia was quantified by measuring short-axis systolic eccentricity of the LV. RESULTS: Before PP, 21 patients (50%) had acute cor pulmonale, defined by RV enlargement associated with septal dyskinesia (group 1), whereas 21 patients had a normal RV (group 2). PP was accompanied by a significant decrease in airway pressure and Paco2. In group 1, this produced a significant decrease in mean (+/-SD) RV enlargement (from 0.91+/-0.22 to 0.61+/-0.21) after 18 h of PP (p=0.000) and a significant reduction in mean septal dyskinesia (from 1.5+/-0.2 to 1.1+/-0.1) after 18 h of PP (p=0.000). CONCLUSION: In the most severe forms of ARDS, PP was an efficient means of controlling RV pressure overload.

Is there a safe plateau pressure in ARDS? The right heart only knows.

OBJECTIVE: Airway pressure limitation is now a largely accepted strategy in adult respiratory distress syndrome (ARDS) patients; however, some debate persists about the exact level of plateau pressure which can be safely used. The objective of the present study was to examine if the echocardiographic evaluation of right ventricular function performed in ARDS may help to answer to this question. DESIGN AND PATIENTS: For more than 20 years, we have regularly monitored right ventricular function by echocardiography in ARDS patients, during two different periods, a first (1980-1992) where airway pressure was not limited, and a second (1993-2006) where airway pressure was limited. By pooling our data, we can observe the effect of a large range of plateau pressure upon mortality rate and incidence of acute cor pulmonale. RESULTS: In this whole group of 352 ARDS patients, mortality rate and incidence of cor pulmonale were 80 and 56%, respectively, when plateau pressure was > 35 cmH(2)O; 42 and 32%, respectively, when plateau pressure was between 27 and 35 cmH(2)O; and 30 and 13%, respectively, when plateau pressure was < 27 cmH(2)O. Moreover, a clear interaction between plateau pressure and cor pulmonale was evidenced: whereas the odd ratio of dying for an increase in plateau pressure from 18-26 to 27-35 cm H(2)O in patients without cor pulmonale was 1.05 (p = 0.635), it was 3.32 in patients with cor pulmonale (p < 0.034). CONCLUSION: We hypothesize that monitoring of right ventricular function by echocardiography at bedside might help to control the safety of plateau pressure used in ARDS.

Validation of a skills assessment scoring system for transesophageal echocardiographic monitoring of hemodynamics.

OBJECTIVE: Transesophageal echocardiography (TEE) is increasingly used in hemodynamic monitoring in the intensive care unit. This paper describes and validates a scoring system for assessing competence in TEE performed by intensivists for this indication. DESIGN: Prospective study over an 18-month period. SETTINGS: Two medical intensive care units. METHODS: The scoring system is used to assess four aspects of TEE: quality of the views (score out of 14); semiquantitative evaluation of respiratory variations in the superior vena cava, valve regurgitation, size of the right ventricle (score out of 10); accuracy of measurement of velocity-time integrals for pulmonary and aortic flow, peak velocity of the E and A waves of mitral flow, left ventricular fractional area change (score out of 8); summary and proposed treatment (score out of 8). The scoring system was validated by using it to assess intensivists after 1 month (M1), 3 months (M3) and 6 months (M6) of training. TEE was done on a mechanically ventilated, hypotensive patient and scored by comparing the intensivist's examination with that of the expert examiner. The intensivists were divided into two groups of theoretical expertise at the start of training. RESULTS: Nineteen intensivists were evaluated. The scores at M1 for level 0 (no experience in echocardiography) and level 1 (previous experience) were, respectively, 18.5 +/- 4 and 24.7 +/- 5. The scores at M1, M3, and M6 were, respectively, 20.4 +/- 5, 30.4 +/- 5 and 35.7 +/- 3. At M6, the intensivists had performed TEE 29 +/- 10 times. CONCLUSION: The scoring system was discriminatory and sensitive to change, and could be used as a tool to assess an intensivist's mastery of TEE.

Efficacy of therapeutic hypothermia after out-of-hospital cardiac arrest due to ventricular fibrillation.

AIM OF THE STUDY: We investigated implementation and efficacy of mild therapeutic hypothermia in the treatment of out-of-hospital cardiac arrest due to ventricular fibrillation. MATERIALS AND METHODS: Two periods were compared, an historical one (36 patients) between 2000 and 2002 where therapeutic hypothermia was never used, and a recent period (32 patients) between 2003 and 2005 where therapeutic hypothermia (32-34 degrees C) was implemented prospectively in our unit. Cooling was obtained by simply using wet cloths and ice packs. Survival in the two groups and factors associated with survival were analysed, together with the neurological prognosis in discharged patients. RESULTS: Survival was significantly higher in the hypothermia group (56% versus 36%), whereas no significant difference was observed in severity between the two periods. Only age, time from return to spontaneous circulation <20min, and therapeutic hypothermia were independently associated with survival. Therapeutic hypothermia was well tolerated and was associated with a significant improvement in neurological outcome. Whereas only 23% of patients actually reached the target temperature in 2003, 100% did in 2005. CONCLUSION: Therapeutic hypothermia is efficient in significantly improving survival and neurological outcome of out-of-hospital cardiac arrest with ventricular fibrillation. By using a simple method, it can be implemented easily and quickly, without side effects.

Bedside echocardiographic evaluation of hemodynamics in sepsis: is a qualitative evaluation sufficient?

OBJECTIVE: Transesophageal echocardiography (TEE) has proven its efficiency in assessing hemodynamics in patients by its ability to evaluate cardiac function and fluid responsiveness. Classically, it requires quantitative measurements, whereas in routine practice TEE is used in our unit especially as a qualitative procedure. We assessed the accuracy of this qualitative central hemodynamic evaluation obtained by TEE at the bedside. DESIGN AND SETTING: Prospective study conducted in a medical ICU between September 2004 and April 2005. All TEE examinations performed in consecutive patients hospitalized for septic shock and mechanically ventilated for an associated acute lung injury were eligible for evaluation. Intensivists trained in echocardiography were asked to classify (a) respiratory changes in the superior vena cava (SVC), (b) left ventricular (LV) systolic function, (c) right ventricular (RV) end-diastolic size, and (d) shape and kinetics of the interventricular septum (IVS). A post-hoc quantitative evaluation was then performed by a trained investigator unaware of the patients' status. RESULTS: We evaluated 83 examinations in 30 patients. Qualitative evaluation was easily able to distinguish patients with significant or nonsignificant SVC respiratory changes, normal, moderately or markedly depressed LV systolic function, and nondilated or dilated right ventricle. Acute cor pulmonale was also well recognized. CONCLUSION: By its ability accurately to evaluate hemodynamic status qualitative TEE could be useful for intensivists in managing circulatory failure in septic shock, rendering the more time-consuming quantitative evaluation useless.

Cardiac function during intraperitoneal CO2 insufflation for aortic surgery: a transesophageal echocardiographic study.

The effect of laparoscopy on cardiac function is controversial. We hypothesized that cardiac dysfunction related to increased afterload could be predominant in patients undergoing elective abdominal aortic repair. To test this hypothesis, we conducted a transesophageal echocardiographic study in 15 patients during laparoscopic aortic surgery. We systematically assessed left ventricular (LV) and right ventricular (RV) functions. Measurements were obtained in the supine position without pneumoperitoneum and with an intraabdominal pressure of 14 mm Hg. Then, patients were turned to the right lateral position without pneumoperitoneum and intraabdominal pressure was increased to 7 mm Hg and to 14 mm Hg. Pneumoperitoneum induced a 25% arterial blood pressure increase and a 38% increase in LV systolic wall stress. A 25% decrease in LV ejection fraction and an 18% decrease in LV stroke volume were observed, associated with an increase in LV end-systolic volume. LV diastolic function impairment was observed without change in LV end-diastolic volume. Respiratory alterations in superior vena cava diameter were never observed, suggesting that volume status remained optimal. Respiratory changes in RV stroke volume were increased according to intraabdominal pressure and body position, reflecting an increase in RV afterload. In conclusion, peritoneal CO2 insufflation in patients scheduled for laparoscopic aortic surgery could impair LV and RV systolic functions as a consequence of increased afterload.

Diagnosis of right ventricular dysfunction in acute pulmonary embolism using helical computed tomography.

Forty-six consecutive patients with pulmonary embolism (PE) who underwent pulmonary angiography, helical computed tomography (CT), and echocardiography in the investigators' emergency department were studied. It was determined that the CT right ventricular (RV)/left ventricular (LV) end-diastolic area ratio was correlated with PE obstruction and echocardiography. A CT RV/LV area ratio >1 had a sensitivity of 88% and a specificity of 88% in diagnosing significant PE. The present study suggests that helical CT may be used as a triage tool in acute PE for selecting high-risk patients, using calculation of the RV/LV area ratio to detect RV dysfunction.

Prone position improves mechanics and alveolar ventilation in acute respiratory distress syndrome.

OBJECTIVE: We tested the hypothesis that ventilation in the prone position might improve homogenization of tidal ventilation by reducing time-constant inequalities, and thus improving alveolar ventilation. We have recently reported in ARDS patients that these inequalities are responsible for the presence of a "slow compartment," excluded from tidal ventilation at supportive respiratory rate. DESIGN: In 11 ARDS patients treated by ventilation in the prone position because of a major oxygenation impairment (PaO(2)/FIO(2)

Incidence, causes and prognosis of hypotension related to meprobamate poisoning.

OBJECTIVE: Meprobamate self-poisoning has been reported as potentially inducing hypotension. We examined the incidence and causes of hypotension induced by this poisoning and its prognosis. DESIGN AND SETTING: Retrospective observational study conducted in a medical ICU between June 1997 and October 2003. Seventy-four patients admitted for meprobamate poisoning and needing mechanical ventilation were included. Demographic, clinical, and laboratory data were compared between patients with and without hypotension. All echocardiograms recorded in patients with hypotension were reviewed, and left ventricular (LV) and right ventricular (RV) functions were assessed. RESULTS: Twenty-nine (40%) patients exhibited hypotension without any significant difference in age, gender, cardiac history, or meprobamate concentration in blood when compared to patients without hypotension. Base excess was significantly lower in patients with hypotension. Echocardiography demonstrated a hypokinetic state, associating decreased LV ejection fraction (45+/-15%) and cardiac index (2+/-0.7 l min(-1) m(-2)), and increased inferior vena cava diameter. Most patients with hypotension received inotropic drugs by infusion, and were ventilated for significantly longer. CONCLUSIONS: Meprobamate self-poisoning induces hypotension, notably related to cardiac failure, in about 40% of cases. This has important therapeutic consequences, as frequent inotropic drug infusion. The mechanisms of cardiac toxicity remain largely unknown, and no predictive factor could be isolated.

Early veno-venous haemodiafiltration for sepsis-related multiple organ failure.

INTRODUCTION: We conducted a prospective observational study from January 1995 to December 2004 to evaluate the impact on recovery of a major advance in renal replacement therapy, namely continuous veno-venous haemodiafiltration (CVVHDF), in patients with refractory septic shock. METHOD: CVVHDF was implemented after 6-12 hours of maximal haemodynamic support, and base excess monitoring was used to evaluate the improvement achieved. Of the 60 patients studied, 40 had improved metabolic acidosis after 12 hours of CVVHDF, with a progressive improvement in all failing organs; the final mortality rate in this subgroup was 30%. In contrast, metabolic acidosis did not improve in the remaining 20 patients after 12 hours of CVVHDF, and the mortality rate in this subgroup was 100%. The crude mortality rate for the whole group was 53%, which is significantly lower than the predicted mortality using Simplified Acute Physiology Score II (79%). CONCLUSION: Early CVVHDF may improve the prognosis of sepsis-related multiple organ failure. Failure to correct metabolic acidosis rapidly during the procedure was a strong predictor of mortality.

Ability and safety of a heated humidifier to control hypercapnic acidosis in severe ARDS.

OBJECTIVE: To assess the ability of a heated humidifier to improve CO(2) clearance in ARDS patients submitted to protective ventilation. DESIGN: Prospective clinical study. SETTING: University hospital intensive care unit. PATIENTS: During a 12-month period, we studied 11 ARDS patients under protective mechanical ventilation with severe hypercapnia. INTERVENTION: When PaCO(2) was above 55 mmHg, the heat and moisture exchanger (HME) was removed and patients were ventilated using a heated humidifier (HH) until their recovery or death. The heated humidifier was inserted on the inspiratory limb of the respirator and the inspirated air was saturated to achieve a temperature of 40 degrees C at the Y connector of ventilator tubing and of 37 degrees C at the outlet of the endotracheal tube. MEASUREMENTS AND RESULTS: Mechanical measurements and blood gas analysis were performed just before removal of the HME, and 30 min after mechanical ventilation using HH. Ventilator parameters were kept constant in the two conditions. Using HH instead of HME, PaCO(2) was safely decreased by 11+/-5 mmHg, without any need to change respiratory rate. No significant difference was noted in intrinsic PEEP or airway plateau pressure. Decrease in PaCO(2) after HME removal was strongly correlated with the initial value of PaCO(2). CONCLUSION: Supposing there is an interest in correcting or limiting hypercapnic acidosis in ARDS patients submitted to protective ventilation, HME removal and use of HH appears to be an efficient and safe way of increasing CO(2) clearance.

Superior vena caval collapsibility as a gauge of volume status in ventilated septic patients.

OBJECTIVE: In mechanically ventilated patients inspiratory increase in pleural pressure during lung inflation may produce complete or partial collapse of the superior vena cava. Occurrence of this collapse suggests that at this time external pressure exerted by the thoracic cavity on the superior vena cava is greater than the venous pressure required to maintain the vessel fully open. We tested the hypothesis that measurement of superior vena caval collapsibility would reveal the need for volume expansion in a given septic patient. DESIGN AND SETTING: Prospective data collection for 66 successive patients in septic shock admitted in a medical intensive care unit and mechanically ventilated for an associated acute lung injury. MEASUREMENTS AND RESULTS: We simultaneously measured superior vena caval collapsibility by echocardiography and cardiac index by the Doppler technique at baseline and after a 10 ml/kg volume expansion by 6% hydroxyethyl starch in 30 min. The threshold superior vena caval collapsibility of 36%, calculated as (maximum diameter on expiration-minimum diameter on inspiration)/maximum diameter on expiration, allowed discrimination between responders (defined by an increase in cardiac index of at least 11% induced by volume expansion) and nonresponders, with a sensitivity of 90% and a specificity of 100%. CONCLUSIONS: Superior vena cava measurement should be systematically performed during routine echocardiography in septic shock as it gives an accurate index of fluid responsiveness.

Respiratory changes in inferior vena cava diameter are helpful in predicting fluid responsiveness in ventilated septic patients.

OBJECTIVE: To evaluate the extent to which respiratory changes in inferior vena cava (IVC) diameter can be used to predict fluid responsiveness. DESIGN: Prospective clinical study. SETTING: Hospital intensive care unit. PATIENTS: Twenty-three patients with acute circulatory failure related to sepsis and mechanically ventilated because of an acute lung injury. MEASUREMENTS: Inferior vena cava diameter (D) at end-expiration (Dmin) and at end-inspiration (Dmax) was measured by echocardiography using a subcostal approach. The distensibility index of the IVC (dIVC) was calculated as the ratio of Dmax - Dmin / Dmin, and expressed as a percentage. The Doppler technique was applied in the pulmonary artery trunk to determine cardiac index (CI). Measurements were performed at baseline and after a 7 ml/kg volume expansion using a plasma expander. Patients were separated into responders (increase in CI > or =15%) and non-responders (increase in CI <15%). RESULTS: Using a threshold dIVC of 18%, responders and non-responders were discriminated with 90% sensitivity and 90% specificity. A strong relation (r = 0.9) was observed between dIVC at baseline and the CI increase following blood volume expansion. Baseline central venous pressure did not accurately predict fluid responsiveness. CONCLUSION: Our study suggests that respiratory change in IVC diameter is an accurate predictor of fluid responsiveness in septic patients.