Vasopressin or norepinephrine in early hyperdynamic septic shock: a randomized clinical trial

Objective To compare the effects of arginine-vasopressin (AVP) and norepinephrine (NE) on hemodynamic variables, organ dysfunction, and adverse events in early hyperdynamic septic shock.Design and setting Randomized, controlled, open-label trial.Patients and participants Twenty-three patients with early (12 h) hyperdynamic septic shock in two teaching hospitals.Interventions AVP (0.04–0.20 U min^–1, n = 13) as a single agent or NE (0.1–2.8 μg kg^–1 min^–1, n = 10) infusion for 48 h to achieve mean arterial pressure at or above 70 mmHg.Measurements and results Hemodynamic parameters and Sequential Organ Failure Assessment (SOFA) score were measured. AVP and NE equally increased mean arterial pressure over 48 h, but NE was required in 36% of AVP patients at 48 h. Compared to baseline, AVP increased systemic vascular resistance, decreased exposure to NE, decreased cardiac output by decreasing heart rate, increased creatinine clearance, and improved SOFA score. The PrCO₂ – PaCO₂ difference remained stable throughout the study. One AVP patient developed acute coronary syndrome with dose-dependent ECG changes. Three patients in both groups died during their ICU stay.Conclusion In early hyperdynamic septic shock, the administration of high-dose AVP as a single agent fails to increase mean arterial pressure in the first hour but maintains it above 70 mmHg in two-thirds of patients at 48 h. AVP decreases NE exposure, has no effect on the PrCO₂ – PaCO₂ difference, and improves renal function and SOFA score.This work was supported by the Cardiovascular Critical Care research Network FRSQ and departmental funding.     

Effects of vertical positioning on gas exchange and lung volumes in acute respiratory distress syndrome

Objective Supine position may contribute to the loss of aerated lung volume in patients with acute respiratory distress syndrome (ARDS). We hypothesized that verticalization increases lung volume and improves gas exchange by reducing the pressure surrounding lung bases.Design and setting Prospective observational physiological study in a medical ICU.Subjects and intervention In 16 patients with ARDS we measured arterial blood gases, pressure-volume curves of the respiratory system recorded from positive-end expiratory pressure (PEEP), and changes in lung volume in supine and vertical positions (trunk elevated at 45° and legs down at 45°).Measurements and results Vertical positioning increased PaO₂ significantly from 94 ± 33 to 142 ± 49 mmHg, with an increase higher than 40% in 11 responders. The volume at 20 cmH₂O measured on the PV curve from PEEP increased using the vertical position only in responders (233 ± 146 vs. –8 ± 91 ml in nonresponders); this change was correlated to oxygenation change (ρ = 0.55). End-expiratory lung volume variation from supine to vertical and 1 h later back to supine, measured in 12 patients showed a significant increase during the 1-h upright period in responders (n = 7) but not in nonresponders (n = 5; 215 ± 220 vs. 10 ± 22 ml), suggesting a time-dependent recruitment.Conclusions Vertical positioning is a simple technique that may improve oxygenation and lung recruitment in ARDS patients.Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Replacement of 24-h creatinine clearance by 2-h creatinine clearance in intensive care unit patients: a single-center study

Objective To estimate the usefulness of 2-h creatinine clearance (CrCl) in the ICU and define variables that may reduce agreement. Design Prospective study. Setting Polyvalent ICU of a university hospital. Patients 359 patients. Interventions We compared 24-h CrCl (CrCl-24h), as the standard measure, with 2-h CrCl (CrCl-2h) (at the start of the period) and the Cockroft–Gault equation (Ck-G). Measurements and results The 2-h sample was lost in two patients (0.6%) and the 24-h sample was lost in 50 patients (13.9%). The mean Ck-G was 87.4 ± 3.05, with CrCl-2h 109.2 ± 4.46 and CrCl-24h 100.9 ± 4.21 ml/min/1.73 m² (r ² of 0.88 for CrCl-2h and 0.84 for Ck-G). The differences from ClCr-24h were 21.8 ± 3.3 ( p < 0.001) for the Ck-G and 8.3 ± 2.6 ( p < 0.05) for CrCl-2h ( p < 0.05). In the subgroup of patients with CrCl-24h < 100 ml/min/1.73 m², the CrCl-24h value was 52.9 ± 2.71 vs. 51.6 ± 2.14 for CrCl-2h ( p = ns) and 57.6 ± 2.56 ( p < 0.001) for the Ck-G. Patients with CrCl < 100 ml/min only showed variability in hyperglycemia during the 24-h period. Conclusions In intensive care patients, 24-h CrCl results in a large proportion of non-valid determinations, even under conditions of close monitoring. Two-hour CrCl is an adequate substitute, even in patients who are unstable or who have irregular diuresis where a 24-h collection is impossible. The Cockroft–Gault equation seems less useful in this setting. All the authors participated actively in the present study. This is an original paper that has not been submitted for publication elsewhere, though partial results of the study were presented at the Annual Congress of the ESICM in Amsterdam (September 2005), and the final results were presented at the Annual Congress of the SEMICYUC (Pamplona, 2006). The authors received no external financing for conduct of the study, and there are no conflicts of interest for any of them. This article is discussed in the editorial available at: .     

Dramatic beneficial effects of sildenafil in recurrent massive pulmonary embolism

Objective Sildenafil has a well established pulmonary vasodilatory effect, but has seldom been used in critically ill patients. We report a case of severe recurrent pulmonary embolism in which sildenafil was used as a rescue therapy. Results After oral administration of 50 mg of sildenafil, cardiac index increased from 2.1 l/min/m² to 3.2 l/min/m²; mean pulmonary artery pressure decreased from 56 mmHg to 46 mmHg, and pulmonary vascular resistance index decreased from 700 dynes/cm⁻⁵/m² to 425 dynes/cm⁻⁵/m², without reduction of arterial systemic pressure. Clinical condition also improved during the following days under treatment of 50 mg sildenafil three times daily. Conclusions These observations should stimulate studies with sildenafil in the ICU setting. Sildenafil is easy to administer in every ICU and at any time. If its potential is confirmed, it may be a life-saving drug in some emergency situations caused by severe pulmonary hypertension. The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.     

Can dynamic indicators help the prediction of fluid responsiveness in spontaneously breathing critically ill patients?

Objective To investigate whether the respiratory changes in arterial pulse (ΔPP) and in systolic pressure (ΔSP) could predict fluid responsiveness in spontaneously breathing (SB) patients. Because changes in intrathoracic pressure during spontaneous breathing (SB) might be insufficient to modify loading conditions of the ventricles, performances of indicators were also assessed during a forced respiratory maneuver. Design Prospective interventional study. Setting A 34-bed university hospital medico-surgical ICU. Patients and participants Thirty-two SB patients with clinical signs of hemodynamic instability. Intervention A 500-ml volume expansion (VE). Measurements and results Cardiac index, assessed using transthoracic echocardiography, increased by at least 15% after VE in 19 patients (responders). At baseline, only dynamic indicators were higher in responders than in nonresponders (13 ± 5% vs. 7 ± 3%, p = 0.003 for ΔPP and 10 ± 4% vs. 6 ± 2%, p = 0.002 for ΔSP). Moreover, they significantly decreased after VE (11 ± 5% to 6 ± 4%, p < 0.001 for ΔPP and 8 ± 4% to 6 ± 3%, p < 0.001 for ΔSP). ΔPP and ΔSP areas under the ROC curve were high (0.81 ± 0.08 and 0.82 ± 0.08; p = 0.888, respectively). A ΔPP ≥ 12% predicted fluid responsiveness with high specificity (92%) but poor sensitivity (63%). The forced respiratory maneuver reproducing a dyspneic state decreased the predictive power. Conclusions Due to their lack of sensitivity and their dependence to respiratory status, ΔPP and ΔSP are clearly less reliable to predict fluid responsiveness during SB than in mechanically ventilated patients. However, when their baseline value is high without acute right ventricular dysfunction in a participating patient, a positive response to fluid is likely. This study was presented at the American Thoracic Society international conference, 2005, San Diego, California. This article is discussed in the editorial available at: .     

Continuous cardiac output monitoring after cardiopulmonary bypass: a comparison with bolus thermodilution measurement

Objective The interchangeability of continuous measurement of cardiac output (CO) with the traditional bolus method in patients after cardiopulmonary bypass (CPB) is uncertain.Design Prospective observational clinical study.Setting A 20-bed surgical ICU at a university hospital.Patients Fourteen deeply sedated, ventilated, post-cardiac surgery patients, all equipped with a pulmonary artery catheter.Interventions Six hours after the end of the CPB, 56 simultaneous bolus and continuous measurements were compared by a linear regression analysis and Bland–Altman analysis. Bolus CO was estimated by averaging triplicate injections of 10 ml room-temperature NaCl 0.9%, delivered randomly during the respiratory cycle. A stringent maximum difference of 0.55 l min^—1 (about 10% of the mean bolus measured) was considered as a clinically acceptable agreement between the two types of measurements. To be interchangeable the limits of agreement (± 2 SD of the mean difference between the two methods) should not exceed the chosen acceptable difference.Measurements and results Continuous was correlated with bolus CO, with a correlation coefficient of r² = 0.68. (p< 0.01). The Bland–Altman analysis demonstrated an objective mean bias of 0.33 ± 0.6 l min^–1 (confidence interval of –0.87 – 1.58) with 34% of measured values falling outside of the clinically acceptable limits.Conclusion Our results suggest that, in the first 6 h after CPB, continuous and bolus CO determinations are not interchangeable; one third of the values obtained by continuous CO fell outside the strict limits of clinically useful precision.Electronic supplementary material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.This work was performed in the Surgical Intensive Care Division at the University Hospital of Geneva, Switzerland.The authors declare no conflict of interest (Financial and non-financial).     

Renal blood flow and function during recovery from experimental septic acute kidney injury

Objective To measure renal blood flow (RBF) and renal function during recovery from experimental septic acute kidney injury (AKI). Design Controlled experimental study. Subjects Nine merino ewes. Setting University physiology laboratory. Intervention We recorded systemic and renal hemodynamics during a 96-h observation period (control) via implanted transit-time flow probes. We then compared this period with 96 h of septic AKI (48 h of Escherichia coli infusion) and subsequent recovery (48 h of observation after stopping E. coli). Measurements and results Compared with the control period, E. coli infusion induced hyperdynamic sepsis (increased cardiac output and decreased blood pressure) and septic AKI (serum creatinine 65.4 ± 8.7 vs. 139.9 ± 33.0 μmol/l; creatinine clearance 73.8 ± 12.2 vs. 40.2 ± 17.2 ml/min; p < 0.05) with a mortality of 22%. RBF increased (278.8 ± 33.9 vs. 547.9 ± 124.8 ml/min; p < 0.05) as did renal vascular conductance (RVC). During recovery, we observed a decrease in RVC and RBF with all values returning to control levels. Indices of tubular function [fractional excretion of sodium (FENa) and urea (FEUn) and urinary sodium concentration (UNa)], which had been affected by sepsis, returned to control values after 18 h of recovery, as did serum creatinine. Conclusions Infusion of E. coli induced a hyperdynamic circulatory state with hyperemic AKI. Recovery was associated with relative renal vasoconstriction and reduction in RBF and RVC back to control levels. Indices of tubular function normalized more rapidly than changes in RBF. This article is discussed in the editorial available at: .     

Plethysmographic dynamic indices predict fluid responsiveness in septic ventilated patients

Objectives In septic patients, reliable non-invasive predictors of fluid responsiveness are needed. We hypothesised that the respiratory changes in the amplitude of the plethysmographic pulse wave (ΔP_PLET) would allow the prediction of changes in cardiac index following volume administration in mechanically ventilated septic patients. Design Prospective clinical investigation. Setting An 11-bed hospital medical intensive care unit. Patients Twenty-three deeply sedated septic patients mechanically ventilated with tidal volume ≥ 8 ml/kg and equipped with an arterial catheter and a pulse oximetry plethysmographic sensor. Interventions Respiratory changes in pulse pressure (ΔPP), ΔP_PLET and cardiac index (transthoracic Doppler echocardiography) were determined before and after volume infusion of colloids (8 ml/kg). Measurements and main results Twenty-eight volume challenges were performed in 23 patients. Before volume expansion, ΔPP correlated with ΔP_PLET (r ² = 0.71, p < 0.001). Changes in cardiac index after volume expansion significantly (p < 0.001) correlated with baseline ΔPP (r ² = 0.76) and ΔP_PLET (r ² = 0.50). The patients were defined as responders to fluid challenge when cardiac index increased by at least 15% after the fluid challenge. Such an event occurred 18 times. Before volume challenge, a ΔPP value of 12% and a ΔP_PLET value of 14% allowed discrimination between responders and non-responders with sensitivity of 100% and 94% respectively and specificity of 70% and 80% respectively. Comparison of areas under the receiver operator characteristic curves showed that ΔPP and ΔP_PLET predicted similarly fluid responsiveness. Conclusion The present study found ΔP_PLET to be as accurate as ΔPP for predicting fluid responsiveness in mechanically ventilated septic patients. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. This work was performed in the Medical Intensive Care Unit, Centre Hospitalier, Belfort, France. Funding: No external funding     

The effect of iNOS deletion on hepatic gluconeogenesis in hyperdynamic murine septic shock

Objective To investigate the role of the inducible nitric oxide synthase activation-induced excess nitric oxide formation on the rate of hepatic glucose production during fully resuscitated murine septic shock. Design Prospective, controlled, randomized animal study. Setting University animal research laboratory. Subjects Male C57Bl/6 and B6.129P2-Nos2^tm1Lau/J (iNOS^−/−) mice. Interventions Fifteen hours after cecal ligation and puncture, anesthetized, mechanically ventilated and instrumented mice (wild-type controls, n = 13; iNOS^−/−, n = 12; wild-type mice receiving 5 mg·kg⁻¹ i.p. of the selective iNOS inhibitor GW274150 immediately after cecal ligation and puncture, n = 8) received continuous i.v. hydroxyethylstarch and norepinephrine to achieve normotensive and hyperdynamic hemodynamics. Measurements and results Measurements were recorded 18, 21 and 24 h after cecal ligation and puncture. Liver microcirculatory perfusion and capillary hemoglobin O₂ saturation (laser Doppler flowmetry and remission spectrophotometry) were well maintained in all groups. Despite significantly lower norepinephrine doses required to achieve the hemodynamic targets, the rate of hepatic glucose production (gas chromatography–mass spectrometry measurements of tissue isotope enrichment during continuous i.v. 1,2,3,4,5,6-¹³C₆-glucose infusion) at 24 h after cecal ligation and puncture was significantly higher in both iNOS^−/− and GW274150-treated mice, which was concomitant with a significantly higher hepatic phosphoenolpyruvate carboxykinase activity (spectrophotometry) in these animals. Conclusions In normotensive, hyperdynamic septic shock, both pharmacologic and genetic deletion of the inducible nitric oxide synthase allowed maintenance of hepatic glucose production, most likely due to maintained activity of the key regulatory enzyme of gluconeogenesis, phosphoenolpyruvate carboxykinase. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. G. Albuszies and J. Vogt contributed equally to this article.     

The changing pathogens of complicated parapneumonic effusions or empyemas in a medical intensive care unit

Objectives To assess the incidence, pathogens, and outcome of complicated parapneumonic effusions or empyemas in a medical intensive care unit (MICU) patients with pleural effusions. Design and setting Prospective study of febrile MICU patients with pleural effusion carried out in a tertiary care hospital between April 2001 and September 2003. Patients The study included 175 patients with a temperature above 38° for more than 8 h with evidence of pleural effusion confirmed by chest radiography and ultrasound. Intervention Routine thoracentesis and effusion cultures. Results The prevalence of complicated parapneumonic effusions or thoracic empyemas in febrile MICU patients with pleural effusions was 45% (78/175). A total of 78 micro-organisms were isolated from the pleural fluid of 58 patients (positive microbiological culture 74%) including aerobic Gram-negative (n = 45), aerobic Gram-positive (n = 23), anaerobic (n = 5), Myobacterium tuberculosis (n = 3), and Candida (n = 2). The infection-related mortality rate of complicated parapneumonic effusions or empyemic patients in the MICU was 41% (32/78). Conclusion The development of complicated parapneumonic effusions or thoracic empyemas in MICU patients is a high-mortality disease. The increasing incidence of aerobic Gram-negative pathogens in empyema has become a more urgent problem. Electronic supplementary material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.     

Goal-directed fluid management reduces vasopressor and catecholamine use in cardiac surgery patients

Objective We examined whether guiding therapy by an algorithm based on optimizing the global end-diastolic volume index (GEDVI) reduces the need for vasopressor and inotropic support and helps to shorten ICU stay in cardiac surgery patients. Design and setting Single-center clinical study with a historical control group at an university hospital. Patients Forty cardiac bypass surgery patients were included prospectively and compared with a control group. Interventions In the goal-directed therapy (GDT) group hemodynamic management was guided by an algorithm based on GEDVI. Hemodynamic goals were: GEDVI above 640 ml/m², cardiac index above 2.5 l/min/m², and mean arterial pressure above 70 mmHg. The control group was treated at the discretion of the attending physician based on central venous pressure, mean arterial pressure, and clinical evaluation. Results In the GDT group duration of catecholamine and vasopressor dependence was shorter (187 ± 70 vs. 1458 ± 197 min), and fewer vasopressors (0.73 ± 0.32 vs. 6.67 ± 1.21 mg) and catecholamines (0.01 ± 0.01 vs. 0.83 ± 0.27 mg) were administered. They received more colloids (6918 ± 242 vs. 5514 ± 171 ml). Duration of mechanical ventilation (12.6 ± 3.6 vs. 15.4 ± 4.3 h) and time until achieving status of fit for ICU discharge (25 ± 13 vs. 33 ± 17 h) was shorter in the GDT group. Conclusions Guiding therapy by an algorithm based on GEDVI leads to a shortened and reduced need for vasopressors, catecholamines, mechanical ventilation, and ICU therapy in patients undergoing cardiac surgery. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Cytokeratin 19 fragments in patients with acute lung injury: a preliminary observation

Objective Cytokeratin 19 (CK19) is a specific cytoskeletal structure for alveolar epithelium. We hypothesized that the levels of CK19 fragments in bronchoalveolar lavage (BAL) fluid could serve as an index of epithelial injury and as a prognosis marker in patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). The aims of our study were, in patients with ALI/ARDS: (1) to measure CK19 fragments concentrations in BAL fluid, (2) to assess its prognostic value, and (3) to identify the cellular source of CK19 in the alveolar space.Design Prospective preliminary study.Setting University hospital surgical ICU.Patients Twenty-two mechanically ventilated patients with ALI/ARDS and 10 non-ventilated control patients. Plasma samples were obtained for 11 ALI/ARDS patients.Measurements and results The concentration of BAL CK19 fragments was higher in patients (median 4916 pg/ml, 25th–75th percentile 2717–10533) than in controls (2208 pg/ml. 767–3923; p = 0.05), and higher in 10 non-survivors (7051 pg/ml, 4372–13371) than in 12 survivors (2888 pg/ml, 1315–5639; p = 0.03 among ALI/ARDS patients). BAL CK19 fragment concentration did not correlate with simplified acute physiologic score, lung injury score or PaO₂/FIO₂ ratio, but correlated positively with BAL albumin concentration (p = 0.002) and with number of BAL macrophages (p = 0.0001). Plasma CK19 fragment concentrations were 10 times lower than those in BAL. Immunohistochemical staining for CK19 showed a strong labelling of injured detached epithelial cells and hyperplastic epithelium in ALI/ARDS lung samples.Conclusion CK19 fragment concentrations were found to be elevated in BAL fluid in ALI/ARDS patients compared with control subjects. High BAL CK19 fragment levels were associated with a poor prognosis.Electronic supplementary material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.     

Short- and long-term outcomes of older patients in intermediate care units

Objective To evaluate short- and long-term outcomes of elderly patients (≥ 65 years) treated at an intermediate care unit (IMCU) and to identify outcome predictors.Design and setting Prospective observational study in the IMCU of a university teaching hospital.Participants We studied 412 patients over 8 months, classified into three groups: under 65 years (control group, n = 158), 65–80 (n = 186), and > 80 (n = 68).Measurements At admission: APACHE II, TISS-28 first day, Charlson Index, diagnosis, and prior Barthel Index. Outcome measures: in-hospital mortality, length of stay, discharge destination, and 2-year mortality and readmissions. Data analysis included multivariate logistic regression and receiver operating characteristics area under the curve (ROC AUC).Results No statistically significant differences between groups were observed in hospital mortality (14.1%), discharge to a long-term facility (2.7%), or 2-year readmissions (1.2 ± 2.1). However, hospital stay was longer in patients aged 65–80 years (14 vs.10 days) and 2-year mortality was higher in those 65 or over (34% vs.10.6%). In the overall series in-hospital mortality was predicted by APACHE II, first-day TISS-28, and diagnosis (ROC AUC 0.81), and 2-year mortality by Charlson Index and age (ROC AUC 0.77). In the elderly patients 2-year mortality was predicted by Charlson and Barthel indices (ROC AUC 0.70).Conclusions Illness severity and therapeutic intervention at admission to IMCU were predictors of short-term mortality, whereas the strongest predictor of long-term mortality was comorbidity. Our results suggest that comprehensive assessment of elderly patients at admission to IMCUs may improve outcome prediction.Electronic supplementary material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.This article is discussed in the editorial available at:     

A self-report-based study of the incidence and associations of sexual dysfunction in survivors of intensive care treatment

Objectives To determine the incidence and associations of sexual dysfunction in survivors of intensive care unit treatment in their first year after hospital discharge using a self-report measure. Design A prospective observational study. Setting ICU Follow-up Clinic, The Royal Berkshire Hospital, Reading. Subjects One hundred and twenty-seven patients aged 18 years and over who spent 3 days or more in the intensive care unit. Main outcome measures Demographic data; reported incidence of sexual dysfunction and post-traumatic stress disorder symptomatology; association between reported sexual dysfunction and age, gender, post-traumatic stress disorder symptomatology and length of intensive care unit stay; patient and partner satisfaction with current sex life. Results Fifty-two patients (43.6%) reported symptoms of sexual dysfunction. There was a significant association between sexual dysfunction and post-traumatic stress disorder symptomatology (p = 0.019). There was no association between reported sexual dysfunction and gender (p = 0.33), age (p = 0.8) or intensive care unit length of stay (p = 0.41). Forty-five per cent of patients and 40% of partners were not satisfied with their current sex life. No other medical practitioner had sought symptoms of sexual dysfunction during the study period. Conclusions Symptoms of sexual dysfunction are common in patients recovering from critical illness and appear to be significantly associated with the presence of post-traumatic stress disorder symptomatology. The intensive care unit follow-up clinic is a suitable forum for the screening and referral of patients with sexual dysfunction. Electronic supplementary material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.     

The combination of the load/force balance and the frequency/tidal volume can predict weaning outcome

Objective To examine whether an appropriately designed combination of an index of ventilatory endurance and the frequency divided by tidal volume ratio (f/V_T) provides prognostic information for weaning outcome not offered by any index alone.Design and setting Prospective study in a multidisciplinary intensive care unit, university hospital.Patients 124 consecutive mechanically ventilated patients.Interventions We designed an index of ventilatory endurance (load/force balance) calculated as the mean inspiratory airway pressure (P_I) during controlled mechanical ventilation/maximum inspiratory pressure (MIP) [P_I equals the triplicate of mean airway pressure (Paw) displayed by the ventilator] and tested its capacity in predicting weaning outcome at 48 h along with f/V_T and many other indices in 75 consecutive mechanically ventilated patients ready to wean. A stepwise discriminant function analysis was used to test the performance of appropriately designed index combination. Threshold values of indices and their combination were prospectively validated in another group of 45 consecutive patients.Results Stepwise discriminant analysis showed that P_I/MIP and f/V_T were the only indices that remained in the model with the function D = 7.628 × mean Paw/MIP + 0.0158 × f/V_T − 2.374. The cutoff point of D = 0.5 had 94% sensitivity, 67% specificity, and 87% correct classifications. Prospective validation demonstrated similar results. The simplified discriminant function D = 15 × mean Paw/MIP + 0.03 × f/V_T − 5 and the cut-off point of D = 1.0 had 89% sensitivity, 67% specificity, and 85% correct classifications.Conclusions The combination of mean Paw/MIP and f/V_T in a simplified discriminant function is useful in predicting weaning outcome.Electronic Supplementary Material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.     

Prevalence of pulmonary hypertension associated with severe acute respiratory distress syndrome: Predictive value of computed tomography

Objective To evaluate the prevalence of pulmonary hypertension associated with severe acute respiratory distress syndrome (ARDS) and to asses the value of pulmonary artery trunk diameter (PAT) to predict pulmonary hypertension. Design Prospective studySetting University teaching hospital and ARDS referral center.Patients 103 patients with ARDS, who received both right heart catheterization and chest computed tomography.Interventions None.Measurements and results 95 patients (92.2%) with ARDS had pulmonary artery hypertension, 16 of them (16.8%) mild, 72 (75.8%) moderate, and 7 (7.4%) severe, as assessed by right heart catheterization. Of the patients with moderate and severe pulmonary hypertension, 43 had a pulmonary artery trunk diameter ≥ 29 mm yielding a sensitivity of 0.54 and a specificity of 0.63. Pulmonary artery trunk diameter correlated significantly but weakly with mean pulmonary artery pressure (r = 0.34, p = 0.0004). The positive predictive value was 0.83, and the negative predictive value was 0.28. The diagnosis of pulmonary hypertension by PAT diameter measurements was incorrect in 43.7% of patients with ARDS.Conclusions Pulmonary artery hypertension has a high prevalence in patients with severe ARDS. Measurement of PAT diameter on admission CT scan is an unreliable tool for identification of ARDS patients with pulmonary hypertension.Electronic supplementary material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.     

Point of care management of heparin administration after heart surgery

Objectives Determination of activated partial thromboplastin time (aPTT) is used in coagulation management after heart surgery. Results from the central laboratory take long to be obtained. We sought to shorten the time to obtain coagulation results and the desired coagulation state and to reduce blood loss and transfusions using point of care (POC) aPTT determination.Design Randomized, controlled trial.Setting University-affiliated 20-bed surgical ICU.Patients and participants Forty-two patients planned for valve surgery (Valves) and 84 for coronary artery bypass grafting (CABG) with cardiopulmonary bypass.Interventions Valves and CABG were randomized to postoperative coagulation management monitored either by central laboratory aPTT (Lab group) or by POC aPTT (POC group). Heparin was administered according to guidelines.Measurements and results POC aPTT results were available earlier than Lab aPTT after venipuncture in Valves (3 ± 2 vs. 125 ± 68 min) and in CABG (3 ± 4 vs. 114 ± 62 min). Heparin was introduced earlier in the POC group in Valves (7 ± 23 vs. 13 ± 78 h, p = 0.01). Valves of the POC group bled significantly less than Valves in the Lab group (647 ± 362 ml vs. 992 ± 647ml, p < 0.04), especially during the first 8 h after ICU admission. There was no difference in bleeding in CABG (1074 ± 869 ml vs. 1102 ± 620, p = NS). In Valves, fewer patients in the POC group than in the Lab group needed blood transfusions (1/21 vs. 8/21; p = 0.03). No difference was detected in CABG.Conclusions In Valves in the POC group the time to the desired coagulation state was reduced, as was the thoracic blood loss, reducing the number of patients transfused. This improvement was not observed in CABG. Side effects were similar in the two groups.Electronic supplementary material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.Presented in part at the annual congress of the European Society of Intensive Care Medicine (ESICM) in Amsterdam, 6–8 October 2003.     

Respiratory load compensation during mechanical ventilation—proportional assist ventilation with load-adjustable gain factors versus pressure support

Rationale In mechanically ventilated patients respiratory system impedance may vary from time to time, resulting, with pressure modalities of ventilator support, in changes in the level of assistance. Recently, implementation of a closed-loop adjustment to continuously adapt the level of assistance to changes in respiratory mechanics has been designed to operate with proportional assist ventilation (PAV+).Objectives The aim of this study was to assess, in critically ill patients, the short-term steady-state response of respiratory motor output to added mechanical respiratory load during PAV+ and during pressure support (PS).Patients and interventions In 10 patients respiratory workload was increased and the pattern of respiratory load compensation was examined during both modes of support.Measurements and results Airway and transdiaphragmatic pressures, volume and flow were measured breath by breath. Without load, both modes provided an equal support as indicated by a similar pressure–time product of the diaphragm per breath, per minute and per litre of ventilation. With load, these values were significantly lower (p < 0.05) with PAV+ than those with PS (5.1 ± 3.7 vs 6.1 ± 3.4 cmH₂O.s, 120.9 ± 77.6 vs 165.6 ± 77.5 cmH₂O.s/min, and 18.7 ± 15.1 vs 24.4 ± 16.4 cmH₂O.s/l, respectively). Contrary to PS, with PAV+ the ratio of tidal volume (V_T) to pressure–time product of the diaphragm per breath (an index of neuroventilatory coupling) remained relatively independent of load. With PAV+ the magnitude of load-induced V_T reduction and breathing frequency increase was significantly smaller than that during PS.Conclusion In critically ill patients the short-term respiratory load compensation is more efficient during proportional assist ventilation with adjustable gain factors than during pressure support.Electronic supplementary material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.     

The prevalence and characteristics of anaemia at discharge home after intensive care

Objective To document the prevalence of anaemia among ICU survivors at the time of discharge home and to document red cell morphology among anaemic patients.Design and setting Observational cohort study in a single-centre teaching hospital.Patients and participants Three cohorts of ICU admissions over a 3-year period managed with restrictive ICU transfusion practice. The study group comprised the 283 patients who survived and were discharged directly home from our hospital.Measurements and results The median time from ICU discharge to hospital discharge was 13 days (IQR 6–22, range 1–119). Using the last recorded Hb concentration 77.4% (95% CI 72.2–82.1) of patients were anaemic, 32.5% (27.3–38.2) had Hb less than 100 g/l, and 11.3% (8.1–15.5) had Hb less than 90 g/l at hospital discharge. Patients who spent longer in intensive care and in hospital after ICU discharge were more likely to be discharged home anaemic. The strongest predictor of discharge home with Hb less than 100 g/l was Hb at the time of ICU discharge. Multivariate regression analysis showed patient age, gender, APACHE II score, and ICU length of stay not to be independent predictors after including the ICU discharge Hb. Among anaemic patients 82% had normochromic normocytic red cell indices, but 12% had red cell hypochromasia and/or microcytosis, which may indicate iron deficiency.Conclusions Anaemia is highly prevalent among survivors of critical illness and persists until hospital discharge. Most patients have red cell morphology similar to “anaemia of chronic disease”.Electronic supplementary material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.     

Effects of a backboard, bed height, and operator position on compression depth during simulated resuscitation

Objective To investigate the effect of a backboard, cardiopulmonary resuscitation (CPR) provider body position and bed height on the quality of chest compression during simulated in-hospital resuscitation.Design and setting Randomised controlled cross-over trial in a university hospital.Participants Second-year medical student basic life support instructors.Interventions Chest compressions performed on a resuscitation manikin placed on a hospital bed with/without a CPR backboard, kneeling on the bed adjacent to the manikin and lowering the height of the bed.Measurements and results Sub-optimal chest compressions were performed on all surfaces. There were no differences in compression depth: standard CPR, 29 ± 7 mm; backboard CPR, 31 ± 10 mm; kneeling on the bed, 30 ± 7 mm; lowering bed height, 32 ± 10 mm. Compression rate and duty cycle were similar on each surface. Participants failed to recognise their poor quality CPR, and there was no difference in assessment of fatigue or efficacy of CPR between surfaces.Conclusions In contrast to current guidelines, the use of a CPR backboard did not improve chest compressions. Furthermore, kneeling on the bed adjacent to the victim or lowering bed height did not impact materially on the quality of chest compression. These findings should be validated in clinical studies.Electronic supplementary material The electronic reference of this article is . The online full-text version of this article includes electronic supplementary material. This material is available to authorised users and can be accessed by means of the ESM button beneath the abstract or in the structured full-text article. To cite or link to this article you can use the above reference.