Oxygenation remains unaffected by increased inspiration-to-expiration ratio but impairs hemodynamics in surfactant-depleted piglets

Objectives Prolongation of inspiratory time is used to reduce lung injury in mechanical ventilation. The aim of this study was to isolate the effects of inspiratory time on airway pressure, gas exchange, and hemodynamics, while ventilatory frequency, tidal volume, and mean airway pressure were kept constant.Design Randomized experimental trial.Setting Experimental laboratory of a University Department of Anesthesiology and Intensive Care.Animals Twelve anesthetised piglets.Interventions After lavage the reference setting was pressure-controlled ventilation with a decelerating flow; IE was 11, and PEEP was set to 75% of the inflection point pressure level. The IE ratios of 1.51, 2.31, and 41 were applied randomly. Under open lung conditions, mean airway pressure was kept constant by reduction of external PEEP.Measurement and results Gas exchange, airway pressures, hemodynamics, functional residual capacity (SF₆ tracer), and intrathoracic fluid volumes (double indicator dilution) were measured. Compared to the IE of 11, PaCO₂ was 8% lower, with IE 2.31 and 41 (p0.01) while PaO₂ remained unchanged. The decrease in inspiratory airway pressure with increased inspiratory time was due to the response of the pressure-regulated volume-controlled mode to an increased IE ratio. Stroke index and right ventricular ejection fraction were depressed at higher IE ratios (SI by 18% at 2.31, 20% at 41; RVEF by 10% at 2.31, 13% at 41;p0.05).Conclusion Under open lung conditions with an increased IE ratio, oxygenation remained unaffected while hemodynamics were impaired.This study was supported by the Swedish Medical Research Council (project 4252), the Swedish Heart-Lung Foundation, Stockholm, Sweden, and the Laerdal Foundation for Acute Medicine, Stavanger, Norway     

Transbronchial regional electroplethysmography of the lungs

Objective. The objective of this study was to describe a method of transbronchial regional electroplethysmography of the lungs.Methods. The electrical resistance of a division of a lung, such as a segment or subsegment, as well as its pulsatile oscillation, were measured using a two-part process: A catheter-transducer was wedged into a small bronchus and the electrical resistance of a blood sample obtained from the same patient was measured. The electroplethysmograph (EPG) was developed for this purpose. The theory behind our method is based on a model of the lung as a three-component structure (blood-tissue-air). We performed experiments on isolated lung lobes of animals, using simultaneous electrometric and direct determination of physiologic indices for regional lung function.Results. Equations have been proposed to calculate blood volume, V_b (±10%); air volume, V_a (±11%); pulsatile increment of the blood volume, V (±10%); and regional stroke volume, RSV (±20%) per 100 cm³ of the lung. The proposed formulas yield an accuracy that is adequate for the clinical range of variations in V_b and V_a, as well as V and RSV. Experiments on lung lobes indicate that the conductivity of lung tissue (_t) is not large. This allows one to calculate the above indices without our having obtained accurate values for conductivity.Conclusions. The method of Transbronchial regional electroplethysmography of the lungs is described and cases in which this method was used for clinical investigation are presented.Glossary Resistivity of suspension - ₁ Resistivity of conducting medium - ₂ Resistivity of conducting spheres - Electroconductivity of the lung at diastole - ₁ Electroconductivity of the lung at systole - _b Electroconductivity of blood - _t Electroconductivity of tissue - _bt Electroconductivity of conducting medium (blood+tissue) - Pulsatile electroconductivity increment in the lung - _e Electrical equivalent of regional stroke volume - V Volume of lung - V_B Blood volume of lung - V_T Tissue volume of lung - V_A Air volume of lung - V_b Regional blood volume per lung volume unit - V_a Regional air volume per lung volume unit - V Regional pulsatile blood increment in the lungs - Ratio of the conducting medium (blood+tissue) volume to the lung volume unit - Ratio of the blood volume to the volume unit of the conducting medium - R Electrical resistance - R Electrical resistance increment - RSV Regional stroke volume per the organ volume unit - F Form-factor - l Cell length - S Cell cross-section area - K Empirical correction coefficient - K₁ Coefficient of electrode installation     

Serum MIP-1α and IL-8 in septic patients

We studied blood MIP-1 and IL-8 in 38 septic patients and 5 healthy volunteers. Both chemokines were undetectable in the healthy volunteers. In sepsis, serum MIP-1 was detected in 45% of the patients and IL-8 in 84%. The levels of MIP-1, but not of IL-8, correlated with CRP, IL-6 and TNF levels. Complication, including various organ failures and mortality, showed no correlation with serum MIP-1 levels. In contrast, we found increased levels of serum IL-8 in septic patients with disseminated intravascular coagulation, central nervous system (CNS) dysfunction or renal failure, and the mortality rate was higher in the IL-8-detectable group than in the IL-8 undetectable group (50% vs 0%,p<0.05). In conclusion, the production of both MIP-1 and IL-8 was increased and initially detectable levels of circulating IL-8 predicted high mortality in sepsis.Objective To determine the significance of the C-C chemokine MIP-1 and the C-X-C chemokine IL-8 in sepsis.Design Prospective study.Setting Clinical investigation, emergency department and general intensive care unit of university hospital.Patients and participants 38 septic patients and 5 healthy volunteers were studied. Sepsis was diagnosed following the criteria formulated by ACCP/SCCM.Interventions 10–20 ml of blood was drawn from each patient at the time of initial diagnosis of sepsis.Measurements and results MIP-1 and IL-8 were determined by sand-wich ELISA. Both chemokines were undetectable in the healthy volunteers. In sepsis, serum MIP-1 was detected in 45% of the patients and IL-8 was detected in 84%. The levels of MIP-1, but not of IL-8, correlated with CRP, IL-6 and TNF levels. Complications, including various organ failures and mortality, showed no correlation with serum MIP-1 levels. In contrast, we found increased levels of serum IL-8 in patients with disseminated intravascular coagulation (DIC) (p<0.05), central nervous system (CNS) dysfunction (p<0.05), renal failure (p<0.01) and the mortality rates were higher in the IL-8 detectable group than in the IL-8 undetectable group (50% vs 0%,p<0.05).Conclusions The production of MIP-1 and IL-8 was increased in sepsis. Furthermore, an initially detectable level of circulating IL-8, but not MIP-1, predicted a high mortality in sepsis diagnosed according to the ACCP/SCCM criteria.This study was supported in part by a Grant-in-Aid from the Japanese Ministry of Education, Science and Culture, the Waxman Institute Research Fund and the Keio Fukuzawa Fund     

Assessment of left ventricular diastolic function with Doppler tissue imaging: effects of preload and place of measurements

Mitral inflow velocities are widely used for the evaluation of left ventricular (LV) diastolic function. However, they are closely affected by other factors such as preload. The purpose of this study was to evaluate the usefulness of tissue Doppler velocities obtained from the mitral annulus for the evaluation of ventricular relaxation in patients under different loading conditions. We also evaluated the effect of preload at different sides on the mitral annulus. The study population consisted of 62 consecutive patients (38 male, 24 female with a mean age of 42 ± 13 years) who have undergone hemodialysis. Both mitral inflow velocities (E wave, A wave, E wave deceleration time and isovolumetric relaxation time) and mitral annulus tissue Doppler velocities (E, A) from the septal, lateral, anterior, posterolateral and inferior sides of the mitral annulus were measured immediately before and after hemodialysis. Mitral inflow E and A wave velocities and E/A ratio decreased significantly (p < 0.001, p = 0.007, p < 0.001, respectively) after hemodialysis. Mitral annulus E wave velocities and E/A ratios obtained from five different sides of the annulus also changed significantly (p < 0.001 for all); however, there was no change in the A wave velocity (p > 0.05 for all) after hemodialysis. The decrease in E wave and E/A ratio in mitral inflow measurements and E velocities and E/A ratios in tissue Doppler measurements were correlated with the amount of fluid extracted (for mitral inflow E wave, r = 0.392, p = 0.002 and E/A ratio, r = 0.280 and p = 0.027; for lateral side E, r = 0.329, p = 0.009 and E/A ratio, r = 0.286, p = 0.04; for septal side E, r = 0.376, p = 0.003 and E/A ratio, r = 0.297, p = 0.019; for anterior side E, r = 0.342, p = 0.007 and E/A ratio, r = 0.268, p = 0.035; for posterolateral side E, r = 0.423, p = 0.001 and E/A ratio, r = 0.343, p = 0.007; and for inferior side E, r = 0.326, p = 0.01 and E/A ratio, r = 0.278, p = 0.029). We conclude that mitral annular velocities obtained by tissue Doppler are preload dependent parameters for the evaluation of LV diastolic function.     

The “Hay-fork” sign in the ultrasonographic diagnosis of intussuception

Ultrasonography was used to evaluate a palpable abdominal mass in a woman. The characteristic hay-fork image led to the correct diagnosis of colocolic intussusception, which had not been suspected. This sign appears to be highly specific for intussusception.     

New aspects of pulmonary mechanics: ‘slowly” distensible compartments of the respiratory system,identified by a PEEP step maneuver

Objective The aims of the present study were 1) to evaluate a method for identification of slowly distensible compartments of the respiratory system (rs), which are characterized by long mechanical time constants (RC) and 2) to identify slowly distensible rs-compartments in mechanically ventilated patients.Design Prospective studyon a physical lung model.Setting Intensive Care Unit, University Hospital, Tübingen.Patients and participants 19 patients with severe lung injury (acute respiratory distress syndrome, ARDS) and on 10 patients with mild lung injury.Measurements and results Positive end-expiratory pressure (PEEP)-increasing and-decreasing steps of about 5 cmH₂O were applied and the breath-by-breath differences of inspiratory and expiratory volumes (V) were measured. The sequence of Vs were analyzed in terms of volume change in the fast compartment (V_fast), the slow compartment (V_slow), total change in lung volume (VL) and mechanical time constant of the slow compartment (RC_slow). Thirty-eight measurements in a lung model revealed a good correlation between the preset V_slow/VL and V_slow/VL measured: r²=0.91 The V_slow/VL measured amounted to 0.94±0.15 of V_slow/VL in the lung model. RC_slow measured was 0.92±0.43 of the RC_slow reference. Starting from a PEEP level of 11 cmH₂O PEEP-increasing and PEEP-decreasing steps were applied to the mechanically ventilated patients. Three out of ten patients with mild lung injury (30%) and 7/19 patients with ARDS (36.8%) revealed slowly distensible rscompartments in a PEEP-increasing step, whereas 15/19 ARDS patients and 1/10 patients with mild lung injury showed slowly distensible rs-compartments in a PEEP-decreasing step (78.9% vs 10%,P<0.002, chi-square test).Conclusions The gas distribution properties of the respiratory system can be easily studied by a PEEP-step maneuver. The relative contribution of the slow units to the total increase of lung volume following a PEEP step could be adequately assessed. Slowly distensible rs-compartments could be detected in patients with severe and mild lung injury, however significantly more ARDS patients revealed slow rs-compartments in PEEP-decreasing steps. The influence of slowly distensible rs-compartments on pulmonary gas exchange is unknown and has yet to be studied.The work was performed at the Klinik für Anaesthesiologie und Transfusionsmedizin der Universität Tübingen     

Tissue Doppler imaging estimation of pulmonary artery occlusion pressure in ICU patients

Objective Earlier reports suggested that transthoracic (TTE) determination of the ratio of mitral inflow E wave velocity to early diastolic mitral annulus velocity (E/E) measured by tissue Doppler imaging (TDI) closely approximates PAOP in cardiac patients. However, the value of E/E for PAOP assessment in ICU patients has not been evaluated. This study assessed whether the E/E ratio provides an accurate estimation of pulmonary artery occlusion pressure (PAOP) in mechanically ventilated ICU patients.Design and setting Prospective, open, clinical study in the ICU of a university hospital.Patients Twenty-three consecutive mechanically ventilated patients.Interventions Volume expansion in 14 patients.Measurements and results Doppler TTE or TEE mitral inflow and TDI mitral annulus velocities were determined and compared with PAOP measured using a Swan-Ganz catheter. Of all the Doppler variables studied the best correlations were observed between PAOP and the lateral (r=0.84) and medial (r=0.76) annulus E/E ratio and remained highly significant when the analysis was restricted to TEE (r=0.91 and 0.86) or TTE (r=0.73 and 0.61). The sensitivities and specificities of estimating PAOP at 15 mmHg or higher were, respectively, 86% and 81% for lateral E/E above 7.5 and 76% and 80% for medial E/E above 9. PAOP changes after volume expansion (700±230 ml) were limited and accurately assessed by repeated E/E determinations.Conclusions In mechanically ventilated ICU patients TTE or TEE E/E determinations using TDI closely approximate PAOP.     

Intrathoracic blood volume accurately reflects circulatory volume status in critically ill patients with mechanical ventilation

Positive pressure ventilation in patients with acute respiratory failure (ARF) may render the interpretation of central venous pressure (CVP) or pulmonary wedge pressure (PCWP) difficult as indicators of circulating volume. The preload component of cardiac (CI) and stroke index (SI) is also influenced by the increased intrathoracic pressures of positive pressure ventilation. Moreover CI and SI do not indicate volume status exclusively but also contractility and afterload. We investigated whether intrathoracic blood volume (ITBV) more accurately reflects blood volume status and the resulting oxygen transport (DO₂). CVP, PCWP, cardiac (CI) and stroke index (SI) were measured, oxygen transport index (DO₂I) and oxygen consumption index (VO₂I) were calculated in 21 ARF-patients. Ventilatory patterns were adjusted as necessary. CI, SI and intrathoracic blood volume index (ITBVI) were derived from thermal dye dilution curves which were detected with a 5 F fiberoptic thermistor femoral artery catheter and fed into a thermaldye-computer. All data were collected in intervals of 6h. There were 224 data sets obtained. Linear regression analysis was performed between absolute values as well as between the 6 h changes (prefix ). The following correlation coefficients were determined: CVP/CI and PCWP/CI 0.01 and –0.142 (p<0.05); CVP/SI and PCWP/SI –0.108 and –0.228 (p<0.01); ITBVI/CI and ITBV/SI 0.488 (p<0.01) and 0.480 (p<0.01); ITBVI and DO₂I 0.460 (p<0.01); CVP/CI and PCWP/CI –0.069 and–0.018; CVP/SI and PCWP/SI –0.083 and –0.009; ITBVI/CI and ITBVI/SI 0.715 (p<0.01) and 0.646 (p<0.01); ITBVI and DO₂I 0.707 (p<0.01). We conclude that in mechanically ventilated patients ITBV is a suitable indicator of circulating blood volume.     

Does psychological characteristic influence physicians’ communication styles? Impact of physicians’ locus of control on interviews with a cancer patient and a relative

Context Physicians psychological characteristics may influence their communication styles and may thus interfere with patient-centred communication.Objective Our aim was to test the hypothesis that, in interviews with a cancer patient and a relative, physicians with an external locus of control (LOC; who believe that life outcomes are controlled by external forces such as luck, fate or others) have a communication style different from that of physicians with an internal LOC (who believe that life outcomes are controlled by their own characteristics or actions).Design, setting, participants and intervention Eighty-one voluntary physicians practising in the field of oncology were recorded while performing an actual and a simulated interview with a cancer patient and a relative.Main outcome measures Physicians communication skills were assessed using the Cancer Research Campaign Workshop Evaluation Manual. Physicians LOC was assessed using the Rotter I–E scale. The communication skills of the upper and lower quartiles of physicians in respect of their scores on this scale were compared using Students t test.Results In actual interviews, physicians with an external LOC talked more to the relative (P=0.017) and used more utterances with an assessment function (P=0.010) than physicians with an internal LOC. In simulated interviews, physicians with an external LOC used less utterances that give premature information (P=0.031) and used more utterances with a supportive function, such as empathy and reassurance (P=0.029), than physicians with an internal LOC.Conclusion These results provide evidence that physicians LOC can influence their communication styles. Physicians awareness of this influence constitutes a step towards a tailoring of their communication skills to every patients and relatives concerns and needs and thus towards a patient-centred communication.This research program was supported by the Fonds National de la Recherche Scientifique—Section Télévie of Belgium, the Fonds dEncouragement à la Recherche de lUniversité Libre de Bruxelles (Brussels, Belgium) and the CAM Training and Research Group (Brussels, Belgium).     

The patients’ perceptions of migraine and chronic daily headache: a qualitative study

This study aimed to gain insight into the management of migraine and chronic daily headache (CDH) from the patients perspective. This article outlines the patients perceptions of migraine and chronic daily headache. Thirteen semi–structured interviews were carried out with patients suffering from IHS migraine. Five patients, due to their headache frequency of more than 15 headache days per month, were classed as CDH patients. The data were transcribed verbatim and analysed in accordance with the grounded theory methodology. The main themes were: headaches, impact and headaches related to health issues. The theme headaches was sub-divided into their pain and symptoms, differentiating between their headaches and perceptions of headaches as barriers and facilitators to management. The patients perceptions of migraine and CDH were sometimes conflicting and influenced the patients management behaviours. The qualitative methodology may help to inform doctors, other healthcare professionals and headache researchers about the patients perspective and possibly develop future headache research, care and education.     

Self-efficacy expectancies versus outcome expectancies as determinants of performance deficits and depressive affect

To compare the depression etiologies specified by self-efficacy theory versus the revised learned helplessness theory, 108 male and female undergraduates were assigned randomly to either high, low, or no self response expectancy manipulations and high, low, or no response outcome expectancy manipulations. Expectancies were modified by combinations of easy or difficult anagrams and graphs showing that most or few students solved the anagrams. Males exhibited performance deficits and depressed affect following manipulations only if self response expectancy had been set low and other response expectancy had been set high. Contrary to revised learned helplessness theory, no performance deficit or depressive affect occurred when both self response and response outcome expectancies were low. Females' performance and affect were not changed by combined low self response and high response outcome manipulations. Repeated subject ratings of self response and response outcome expectancies during manipulations suggest that females set their self response expectancies low before manipulations to avoid depression. Expectancy ratings also showed that self response expectancies correlated more strongly with performance than did response outcome expectancies.We thank Katherine Acosta, Michael Davis, Larry McFarland, and Janine Tronolone for their assistance as experimenters.     

Pharmacognosie du ginseng: état des lieux. La notion d’adaptogène mise en question*

Résumé: A loccasion dune mise au point critique sur les principes actifs du ginseng, on confirme quil est toujours difficile de se faire une opinion claire et précise des qualités de cette «fabuleuse» racine. La majorité des articles tourne autour de sa qualité dadaptogène, terme quil est urgent de définir avec précision pour en finir avec les discours tautologiques. Restent enfin lenjeu commercial qui pousse à lhagiogra-phie et lexotisme qui exalte la crédulité des consommateurs.* Communication présentée lors de la 12^e Journée universitaire de lAMPP septembre 2003 : Ginseng et autres plantes adaptogènes.     

Transthoracic electrical impedance during extracorporeal hemodialysis in acute respiratory failure (“Shocked lung syndrome”)

The alteration (Z ₀ ) of transthoracic electrical impedance (TEI) during extracorporeal hemodialysis (EHD) was investigated in two Groups of patients with acute renal and acute respiratory failure, that differed with respect to the severity of respiratory insufficiency. Group I had moderate respiratory failure (Fi _{O 2} 0.31±0.10, Pa _{0 2} 84±14 mmHg), and Group II had severe respiratory failure (Fi _{0 2} 0.75±0.17, Pa _{O O} 77±14 mmHg). There was a significant correlation between increase in TEI (Z₀) and decrease in body weight (BW) in each individual patient, but the slope of regression lines was remarkably flattened in Group II. In Group I, TEI was 1.9±0.9 , the calculated TEI for 500 gr decrease in BW (Z_{0–500 gr}) was 0.59±0.21 , and a significant correlation existed between pooled data of Z₀ and BW. In Group II TEI increased less significantly, TEI was 0.6±0.3 (P<0.001), Z_{0–500 gr} was 0.26±0.27 (P<0.01), and there was no correlation between pooled data of Z₀ and BW. Increase of TEI in Group II could be completely attributed to increase in hematocrit. It is concluded that patients of Group I with acute renal failure and moderate respiratory failure lost intrathoracic fluid during EHD, whereas patients of Group II with severe respiratory failure did not. TEI during EHD may serve as a test for detection of fixed fluid within the pulmonary interstitium indicating a poor prognosis of the acute respiratory failure.     

Enquête ethnobotanique: screening chimique et efficacité thérapeutique de quelques plantes utilisées contre le paludisme en médecine traditionnelle à Brazzaville

Résumé: Les effets antipaludiques des extraits de trois plantes de la pharmacopée traditionnelle congolaise, Cassia siamea, Cassia spectabilis, Tetracera alnifolia (sélectionnées à partir dune enquête ethnobotanique), ont été étudiés chez des malades (20 pour chaque extrait) présentant une goutte épaisse positive et une hyperthermie. Les grandes familles chimiques de lextrait le plus efficace ont été recherchées en utilisant les méthodes phytochimiques classiques. Lextrait aqueux de Cassia siamea a présenté leffet antipaludique le plus important (sur la parasitémie et lhyperthermie); cette intéressante activité du Cassia siamea pourrait sexpliquer par la présence des alcaloïdes et des quinones.     

L’anis vert (<Emphasis Type="Italic">Pimpinella anisum L.</Emphasis>)

Résumé: Dans cet article, lauteur donne des informations sur lutilisation de lanis vert, Pimpinella anisum L., sous forme de tisane. Il expose rapidement laspect historique concernant notamment la médecine traditionnelle et plus particulièrement celle dEurope centrale. Il propose des formulations de tisanes encore utilisables de nos jours en phytothérapie quotidienne.     

Phyto News

PHYTO NEWS est la revue commentée de communications dans le domaine de la plante médicinale (recherche pharmacologique et clinique), qui nous semble présenter un intérêt médical ou pharmaceutique tel quil puisse permettre de faire progresser dautres études qui aboutiront à une application thérapeutique. Il est cependant important davertir les lecteurs que dune découverte ou dune démonstration pharmacologique ne découle pas immédiatement la justification de lutilisation médicale.

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Phyto-News is a commented review of papers about medicinal plant researches all around the world. The papers must contain information leading to medicinal progress in phytotherapie practice or development in the pharmaceutical area. The reader is advised that not all discoveries will have immediate use in medicine, but each may give ideas for further investigations.

     

Monitoring of respiratory variations of aortic blood flow velocity using esophageal Doppler

Objective The purpose of this study was to determine whether monitoring of respiratory changes in aortic blood flow velocity, recorded by esophageal Doppler, could be used to detect changes in volume depletion.Design Animal study.Animals and interventions After general anesthesia and tracheotomy, ten New Zealand female rabbits, weighing 4–4.5 kg were studied under mechanical ventilation at a fixed tidal volume; during this time 5-ml blood samples were withdrawn (in increments up to a total of 30 ml) and then retransfused.Measurements and results At each step, systolic (SBP), diastolic (DBP), pulse (PP) pressures and maximum descending aortic blood flow (V) were recorded. Respiratory changes of V (V), SBP (SBP) and PP (PP) were calculated as the difference of maximal and minimal values divided by their respective means and expressed as a percentage. The amount of blood withdrawn correlated negatively with SBP, DBP, PP and V and positively with SBP, PP and V. Among these parameters, V correlated best with the amount of blood withdrawn (r=0.89, p<0.001) and it was the most accurate index of volume depletion.Conclusion Monitoring of the respiratory variation in V, calculated by esophageal Doppler technique, seems to be a highly accurate index of blood volume depletion and restitution.Supported by Philips Medical System and Arrow.     

Solubilisation aqueuse d’une huile essentielle

Résumé: Le but de létude présentée ici est la formulation de solutions aqueuses dhuile essentielle de pin sylvestre (Pinus sylvestris. L, Abiétacées) de faible viscosité, limpides, stables et transparentes. Des solutions micellaires sont donc envisagées à laide de surfactifs et dadjuvants de solubilisation. La condition retenue a été lobtention de solutions formulées avec des quantités minimales de surfactifs.     

The respiratory variation in inferior vena cava diameter as a guide to fluid therapy

Objective To investigate whether the respiratory variation in inferior vena cava diameter (D_IVC) could be related to fluid responsiveness in mechanically ventilated patients.Design Prospective clinical study.Setting Medical ICU of a non-university hospital.Patients Mechanically ventilated patients with septic shock (n=39).Interventions Volume loading with 8 mL/kg of 6% hydroxyethylstarch over 20 min.Measurements and results Cardiac output and D_IVC were assessed by echography before and immediately after the standardized volume load. Volume loading induced an increase in cardiac output from 5.7±2.0 to 6.4±1.9 L/min (P<0.001) and a decrease in D_IVC from 13.8±13.6 vs 5.2±5.8% (P<0.001). Sixteen patients responded to volume loading by an increase in cardiac output 15% (responders). Before volume loading, the D_IVC was greater in responders than in non-responders (25±15 vs 6±4%, P<0.001), closely correlated with the increase in cardiac output (r=0.82, P<0.001), and a 12% D_IVC cut-off value allowed identification of responders with positive and negative predictive values of 93% and 92%, respectively.Conclusion Analysis of D_IVC is a simple and non-invasive method to detect fluid responsiveness in mechanically ventilated patients with septic shock.