Nurse-determined assessment of cardiac output. Comparing a non-invasive cardiac output device and pulmonary artery catheter: A prospective observational study

Background

The accurate measurement of Cardiac output (CO) is vital in guiding the treatment of critically ill patients. Invasive or minimally invasive measurement of CO is not without inherent risks to the patient. Skilled Intensive Care Unit (ICU) nursing staff are in an ideal position to assess changes in CO following therapeutic measures. The USCOM (Ultrasonic Cardiac Output Monitor) device is a non-invasive CO monitor whose clinical utility and ease of use requires testing.

Objectives

To compare cardiac output measurement using a non-invasive ultrasonic device (USCOM) operated by a non-echocardiograhically trained ICU Registered Nurse (RN), with the conventional pulmonary artery catheter (PAC) using both thermodilution and Fick methods.

Design

Prospective observational study.

Setting and participants

Between April 2006 and March 2007, we evaluated 30 spontaneously breathing patients requiring PAC for assessment of heart failure and/or pulmonary hypertension at a tertiary level cardiothoracic hospital.

Methods

SCOM CO was compared with thermodilution measurements via PAC and CO estimated using a modified Fick equation. This catheter was inserted by a medical officer, and all USCOM measurements by a senior ICU nurse. Mean values, bias and precision, and mean percentage difference between measures were determined to compare methods. The Intra-Class Correlation statistic was also used to assess agreement. The USCOM time to measure was recorded to assess the learning curve for USCOM use performed by an ICU RN and a line of best fit demonstrated to describe the operator learning curve.

Results

In 24 of 30 (80%) patients studied, CO measures were obtained. In 6 of 30 (20%) patients, an adequate USCOM signal was not achieved. The mean difference (±standard deviation) between USCOM and PAC, USCOM and Fick, and Fick and PAC CO were small, −0.34 ± 0.52 L/min, −0.33 ± 0.90 L/min and −0.25 ± 0.63 L/min respectively across a range of outputs from 2.6 L/min to 7.2 L/min. The percent limits of agreement (LOA) for all measures were −34.6% to 17.8% for USCOM and PAC, −49.8% to 34.1% for USCOM and Fick and −36.4% to 23.7% for PAC and Fick. Signal acquisition time reduced on average by 0.6 min per measure to less than 10 min at the end of the study.

Conclusions

In 80% of our cohort, USCOM, PAC and Fick measures of CO all showed clinically acceptable agreement and the learning curve for operation of the non-invasive USCOM device by an ICU RN was found to be satisfactorily short. Further work is required in patients receiving positive pressure ventilation.     

Continuous minimally invasive peri-operative monitoring of cardiac output by pulmonary capnotracking: comparison with thermodilution and transesophageal echocardiography

A number of technologies are available for minimally-invasive cardiac output measurement in patients during surgery but remain little used. A system has been developed based on CO₂ elimination (VCO₂) by the lungs for use in ventilated patients, which can be fully integrated into a modern anesthesia/monitoring platform, and provides semi-automated, continuous breath-by-breath cardiac output monitoring. A prototype measurement system was constructed to measure VCO₂ and end-tidal CO₂ concentration with each breath. A baseline measurement of non-shunt cardiac output was made during a brief change in ventilator rate, according to the differential CO₂ Fick approach. Continuous breath-by-breath monitoring of cardiac output was then performed from measurement of VCO₂, using a derivation of the Fick equation applied to pulmonary CO₂ elimination. Automated recalibration was done periodically and data was processed and cardiac output displayed in real time. Measurements were compared with simultaneous measurements by bolus thermodilution in 77 patients undergoing cardiac surgery or liver transplantation. Overall mean bias [sd] for agreement in cardiac output measurement was −0.1 [1.2] L/min, percentage error +44.2%, r = 0.92. Concordance in measurement of changes of at least 15% in cardiac output was 80%. The method followed sudden changes in cardiac output due to arrythmias and run onto cardiopulmonary bypass in real time. The accuracy and precision were comparable to other clinical techniques. The method is relatively seamless and largely automated and has potential for continuous, cardiac output monitoring in ventilated patients during anesthesia and critical care.     

Continuous and intermittent cardiac output measurement in hyperdynamic conditions: pulmonary artery catheter vs. lithium dilution technique

OBJECTIVE: This study aimed to assess the level of agreement of both intermittent cardiac output monitoring by the lithium dilution technique (CO(Li)) and continuous cardiac output monitoring (PulseCO(Li)) using the arterial pressure waveform with intermittent thermodilution using a pulmonary artery catheter (CO(PAC)). DESIGN: Prospective, single-center evaluation. SETTING: University Hospital Intensive Care Unit. PATIENTS: Patients (n=23) receiving liver transplantation. INTERVENTION: Pulmonary artery catheters were placed in all patients and CO(PAC) was determined using thermodilution. CO(Li) and PulseCO(Li) measurements were made using the LiDCO system. MEASUREMENTS AND MAIN RESULTS: Data were collected after intensive care unit admission and every 8h until the 48th hour. A total of 151 CO(PAC), CO(Li) and PulseCO(Li) measurements were analysed. Bias and 95% limit of agreement were 0.11lmin(-1) and -1.84 to + 2.05 lmin(-1) for CO(PAC) vs. CO(Li) (r=0.88) resulting in an overall percentage error of 15.6%. Bias and 95% limit of agreement for CO(PAC) vs. PulseCO(Li) were 0.29 lmin(-1) and -1.87 to + 2.46 lmin(-1) (r=0.85) with a percentage error of 16.8%. Subgroup analysis revealed a percentage error of 15.7% for CO(PAC) vs. CO(Li) and 15.1% for CO(PAC) vs. PulseCO(Li) for data pairs less than 8 lmin(-1), and percentage errors of 15.5% and 18.5% respectively for data pairs higher than 8 lmin(-1). CONCLUSION: In patients with hyperdynamic circulation, intermittent and continuous CO values determined using the LiDCO system showed good agreement with those obtained by intermittent pulmonary artery thermodilution.     

Continuous blood pressure monitoring via non-invasive radial artery applanation tonometry and invasive arterial catheter demonstrates good agreement in patients undergoing colon carcinoma surgery

Purpose

Radial artery applanation tonometry (RAAT) has been developed and utilized for continuous arterial pressure monitoring. However, evidence is lacking to clinically verify the RAAT technology and identify appropriate patient groups before routine clinical use. This study aims to evaluate the RAAT technology by comparing systolic blood pressure (SBP), mean blood pressure (MBP) and diastolic blood pressure (DBP) values in patients undergoing colon carcinoma surgery.

Methods

Blood Pressure (BP) values obtained via RAAT (TL-300, Tensys Medical Inc., San Diego, CA, USA) and conventional arterial catheterization from 30 colon carcinoma surgical patients were collected and compared via Bland-Atman method, linear regression and 4-quadrant plot concordance analysis.

Results

For SBPs, MBPs and DBPs, means of the differences (±standard deviation; 95% limits of agreement) were ?0.9 (±7.6; ?15.7 to 13.9) mmHg, 3.1 (±6.5; ?9.6 to 15.8) mmHg and 4.3 (±7.4; ?10.3 to 18.8) mmHg, respectively. Linear regression coefficients of determination were 0.8706 for SBPs, 0.8353 for MBPs and 0.6858 for DBPs. Four-quadrant concordance correlation coefficients were 0.8740, 0.8522 and 0.7108 for SBPs, MBPs and DBPs, respectively.

Conclusions

A highly selected patient collective undergoing colon carcinoma surgery was studied. BP measurements obtained via the TL-300 had clinically acceptable agreement with that acquired invasively using an arterial catheter. For use in clinical routine, it is necessary to take measures for improvement regarding movement artifacts and dilution of noise. A large sample size of patients under various conditions is also needed to further evaluate the RAAT technology before clinically routine use.

     

Comparison of an advanced minimally invasive cardiac output monitoring with a continuous invasive cardiac output monitoring during lung transplantation

The aim of this study was to compare a continuous non-calibrated left heart cardiac index (CI) measurement by arterial waveform analysis (FloTrac^®/Vigileo^®) with a continuous calibrated right heart CI measurement by pulmonary artery thermodilution (CCOmbo-PAC^®/Vigilance II^®) for hemodynamic monitoring during lung transplantation. CI was measured simultaneously by both techniques in 13 consecutive lung transplants (n = 4 single-lung transplants, n = 9 sequential double-lung transplants) at distinct time points perioperatively. Linear regression analysis and Bland–Altman analysis with percentage error calculation were used for statistical comparison of CI measurements by both techniques. In this study the FloTrac^® system underestimated the CI in comparison with the continuous pulmonary arterial thermodilution (p < 0.000). For all measurement pairs we calculated a bias of ?0.55 l/min/m² with limits of agreement between ?2.31 and 1.21 l/min/m² and a percentage error of 55 %. The overall correlations before clamping a branch oft the pulmonary artery (percentage error 41 %) and during the clamping periods of a branch oft the pulmonary artery (percentage error 66 %) failed to reached the required percentage error of less than 30 %. We found good agreement of both CI measurements techniques only during the measurement point “15 min after starting the second one-lung ventilation period” (percentage error 30 %). No agreement was found during all other measurement points. This pilot study shows for the first time that the CI of the FloTrac^® system is not comparable with the continuous pulmonary-artery thermodilution during lung transplantation including the time periods without clamping a branch of the pulmonary artery. Arterial waveform and continuous pulmonary artery thermodilution are, therefore, not interchangeable during these complex operations.     

Accidental catheter removal in critically ill patients: a prospective and observational study

Introduction  

The importance of accidental catheter removal (ACR) lies in the complications caused by the removal itself and by catheter reinsertion. To the best of our knowledge, no studies have analyzed accidental removal of various types of catheters in the intensive care unit (ICU). The objective of the present study was to analyze the incidence of ACR for all types of catheters in the ICU.     

Introducing intravascular microdialysis for continuous lactate monitoring in patients undergoing cardiac surgery: a prospective observational study

Introduction

Lactate is a marker of hypoperfusion and may be used for risk assessment in critically ill patients. Although evidence suggests that repeated lactate measurements are of clinical interest, how and when lactate should be analyzed is controversial. Intravascular microdialysis provides a novel method for the continuous monitoring of lactate, which may be clinically beneficial in critically ill patients.

Methods

Circulating lactate levels were continuously monitored in 80 patients undergoing cardiac surgery using either a separate single-lumen microdialysis catheter or a triple-lumen central venous catheter with an integrated microdialysis function. The catheter was placed with the tip positioned in the superior vena cava. Arterial blood gas samples were taken every hour to obtain reference values, and the lactate levels were analyzed in a blood gas analyzer.

Results

A total of 1,601 paired microdialysis–arterial blood gas lactate samples were obtained. Bland-Altman analysis showed a bias (mean difference) ± limits of agreement (±1.96 SD) of 0.02 ± 0.42 mmol/L. The regression coefficient was 0.98 (P = 0.0001).

Conclusions

Central venous microdialysis is an accurate and reliable method for continuous blood lactate monitoring in patients undergoing cardiac surgery. The system may be useful for early lactate-guided therapy in critically ill patients.     

Relationship between catheter care and catheter-associated urinary tract infection at Japanese general hospitals: a prospective observational study

BACKGROUND: The risk factors for catheter-associated urinary tract infections (CAUTIs) that are associated with catheter care have not been examined in detail by prospective studies or randomised clinical trials. OBJECTIVES: To examine the patterns of catheter care and to identify the CAUTI risk factors associated with catheter care. DESIGN: Prospective observational study. METHODS: Between January and December 2004, 555 adult patients who were catheterised for 3 days in five general hospitals in Japan were surveyed. One researcher collected the following data twice a week: catheter insertion method, catheter management, and signs and symptoms of urinary tract infections. The relative risk exceeding 1 by the Poisson regression were selected for Cox proportional hazard analysis in order to calculate adjusted risks. In addition, expected reductions in the incidence of CAUTIs by elimination of the risk factors were estimated using the population attributable risk percent. RESULTS: The mean duration of catheterisation was 25 days. The overall incidence of CAUTIs was 3.9 cases per 1000-device days; the incidence of CAUTIs ranged from 0.6 to 7.2 cases per 1000-device days among the five hospitals. Only fecal incontinent patients were analysed since they accounted for 94% of the CAUTI cases. In the univariate analysis, the silver-alloy catheter, which contains antimicrobial property, emerged as a potential risk. Since silver-alloy catheters were used in only one hospital, silver-alloy catheter care was compared with that of the other types of catheter, and a significantly higher percentage of inappropriate care was observed. In the final Cox model, two variables remained: 'non-pre-connected closed system (standard system)' (RR 2.35, 95%CI 1.20-4.60, p = 0.013) and 'no daily cleansing of the perineal area' (RR 2.49, 95%CI 1.32-4.69, p = 0.005). The population attributable risk percent suggested that the use of a 'pre-connected closed system' and 'daily cleansing of the perineal area' could reduce the incidence of CAUTIs by nearly 50%. CONCLUSIONS: Our investigation identified fecal incontinence as the major risk factor for CAUTIs in the study population. However, attributable risk percent indicates that the implementation of two basic elements of catheter care could reduce CAUTIs by nearly 50%. The hospital using silver-alloy catheters had the highest CAUTI rates, strongly suggesting the hazards of relying on the antimicrobial property of silver and the resultant laxity in care.     

Monitoring in resuscitation: Comparison of cardiac output measurement between pulmonary artery catheter and NICO

Aim

The cardiac output and coronary perfusion pressure generated from chest compressions during resuscitation manoeuvres can predict effectiveness and successful outcome. Until now, there is no good method for haemodynamic monitoring during resuscitation. Noninvasive partial carbon dioxide rebreathing system (NICO, Novametrix Medical Systems, Inc., Wallingford, CT, USA) is a relatively new non-invasive alternative to thermodilution for measuring cardiac output. The accuracy of the NICO system has not been evaluated during resuscitation. The aim of this study is to compare thermodilution cardiac output method with NICO system and to assess the utility of NICO during resuscitation.

Methods and design

Experimental study in 24 Yorkshire pigs.Paired measurements of cardiac output were determined during resuscitation (before ventricular fibrillation and after 5, 15, 30 and 45 min of resuscitation) in the supine position. The average of 3 consecutive thermodilution cardiac output measurements (10 ml 20 °C saline) was compared with the corresponding NICO measurement.

Results

Bland and Altman plot and Lin's concordance coefficient showed a high correlation between NICO and thermodilution cardiac output measurements although NICO has a tendency to underestimate cardiac output when compared to thermodilution at normal values of cardiac output.

Conclusions

There is a high degree of agreement between cardiac output measurements obtained with NICO and thermodilution cardiac output during resuscitation.The present study suggests that the NICO system may be useful to measure cardiac output generated during cardiopulmonary resuscitation.     

An observational study of bispectral index monitoring for out of hospital cardiac arrest

Cerebral resuscitation is the most important goal of advanced life support. Currently, there are no objective monitoring methods available to gauge the effectiveness of advanced life support on cerebral resuscitation. We assessed the utility of bispectral index (BIS) monitoring during cardiopulmonary resuscitation as a marker of cerebral resuscitation. Twenty one patients with out of hospital cardiac arrest had a BIS monitor applied during the resuscitation, in addition to standard advanced life support. The BIS monitor was also applied to a cadaver to assess the role of artefact. Illustrative data are presented, outlining the process of evaluation undertaken. A major component of the BIS tracing during external chest compressions appears to be due to movement artefact. Our pilot data indicate that with current technology, BIS monitoring is not a clinically reliable marker of the efficacy of external chest compressions.     

Severe electrolyte disorders following cardiac surgery: a prospective controlled observational study

Introduction

Electrolyte disorders are an important cause of ventricular and supraventricular arrhythmias as well as various other complications in the intensive care unit. Patients undergoing cardiac surgery are at risk for development of tachyarrhythmias, especially in the period during and immediately after surgical intervention. Preventing electrolyte disorders is thus an important goal of therapy in such patients. However, although levels of potassium are usually measured regularly in these patients, other electrolytes such as magnesium, phosphate and calcium are measured far less frequently. We hypothesized that patients undergoing cardiac surgical procedures might be at risk for electrolyte depletion, and we therefore conducted the present study to assess electrolyte levels in such patients.

Methods

Levels of magnesium, phosphate, potassium, calcium and sodium were measured in 500 consecutive patients undergoing various cardiac surgical procedures who required extracorporeal circulation (group 1). A total of 250 patients admitted to the intensive care unit following other major surgical procedures served as control individuals (group 2). Urine electrolyte excretion was measured in a subgroup of 50 patients in both groups.

Results

All cardiac patients received 1 l cardioplegia solution containing 16 mmol potassium and 16 mmol magnesium. In addition, intravenous potassium supplementation was greater in cardiac surgery patients (mean ± standard error: 10.2 ± 4.8 mmol/hour in cardiac surgery patients versus 1.3 ± 1.0 in control individuals; P < 0.01), and most (76% versus 2%; P < 0.01) received one or more doses of magnesium (on average 2.1 g) for clinical reasons, mostly intraoperative arrhythmia. Despite these differences in supplementation, electrolyte levels decreased significantly in cardiac surgery patients, most of whom (88% of cardiac surgery patients versus 20% of control individuals; P < 0.001) met criteria for clinical deficiency in one or more electrolytes. Electrolyte levels were as follows (mmol/l [mean ± standard error]; cardiac patients versus control individuals): phosphate 0.43 ± 0.22 versus 0.92 ± 0.32 (P < 0.001); magnesium 0.62 ± 0.24 versus 0.95 ± 0.27 (P < 0.001); calcium 1.96 ± 0.41 versus 2.12 ± 0.33 (P < 0.001); and potassium 3.6 ± 0.70 versus 3.9 ± 0.63 (P < 0.01). Magnesium levels in patients who had not received supplementation were 0.47 ± 0.16 mmol/l in group 1 and 0.95 ± 0.26 mmol/l in group 2 (P < 0.001). Urinary excretion of potassium, magnesium and phosphate was high in group 1 (data not shown), but this alone could not completely account for the observed electrolyte depletion.

Conclusion

Patients undergoing cardiac surgery with extracorporeal circulation are at high risk for electrolyte depletion, despite supplementation of some electrolytes, such as potassium. The probable mechanism is a combination of increased urinary excretion and intracellular shift induced by a combination of extracorporeal circulation and decreased body temperature during surgery (hypothermia induced diuresis). Our findings may partly explain the high risk of tachyarrhythmia in patients who have undergone cardiac surgery. Prophylactic supplementation of potassium, magnesium and phosphate should be seriously considered in all patients undergoing cardiac surgical procedures, both during surgery and in the immediate postoperative period. Levels of these electrolytes should be monitored frequently in such patients.     

阿托伐他汀联合微创置管引流术与单行纯微创置管引流术治疗慢性硬膜下血肿患者的优劣差异

目的 探讨阿托伐他汀联合经锥颅微创置管引流术与单行纯经锥颅微创置管引流术治疗慢性硬膜下血肿患者(CSDH)的临床疗效差异。方法 选取我院2016年1月至2018年12月CSDH患者62例,随机分为对照组(30例)和观察组(32例);对照组予以经锥颅微创置管引流术治疗;观察组予以微创置管引流术+阿托伐他汀治疗。观察两组临床疗效,神经功能缺损(CSS)评分、日常生活活动能力量表(ADL)评分及并发症、疾病复发情况。结果 治疗后,观察组临床疗效明显高于对照组(P<0.05);观察组CSS评分低于对照组(P<0.05),ADL评分明显高于对照组(P<0.05);观察组总并发症发生率和复发率明显低于对照组(P<0.05)。结论 阿托伐他汀联合经锥颅微创置管引流术治疗CSDH,清除颅内血肿,改善患者神经功能,能达到更好的临床疗效。     

Pulmonary artery catheter versus pulse contour analysis: a prospective epidemiological study

Introduction

The choice of invasive systemic haemodynamic monitoring in critically ill patients remains controversial as no multicentre comparative clinical data exist. Accordingly, we sought to study and compare the features and outcomes of patients who receive haemodynamic monitoring with either the pulmonary artery catheter (PAC) or pulse contour cardiac output (PiCCO) technology.

Methods

We conducted a prospective multicentre, multinational epidemiological study in a cohort of 331 critically ill patients who received haemodynamic monitoring by PAC or PiCCO according to physician preference in intensive care units (ICUs) of eight hospitals in four countries. We collected data on haemodynamics, demographic features, daily fluid balance, mechanical ventilation days, ICU days, hospital days, and hospital mortality. We statistically compared the two techniques.

Results

Three hundred and forty-two catheters (PiCCO 192 and PAC 150) were inserted in 331 patients. On direct comparison, patients with PAC were older (68 versus 64 years of age; p = 0.0037), were given inotropic drugs more frequently (37.3% versus 13%; p < 0.0001), and had a lower cardiac index (2.6 versus 3.2 litres/minute per square meter; p < 0.0001). Mean daily fluid balance was significantly greater during PiCCO monitoring (+659 versus +350 ml/day; p = 0.017) and mechanical ventilation-free days were fewer (12 for PiCCO versus 21 for PAC; p = 0.045). However, after multiple regression analysis, we found no significant effect of monitoring technique on mean daily fluid balance, mechanical ventilation-free days, ICU-free days, or hospital mortality. A secondary multiple logistic regression analysis for hospital mortality which included mean daily fluid balance showed that positive fluid balance was a significant predictor of hospital mortality (odds ratio = 1.0002 for each ml/day; p = 0.0073).

Conclusion

On direct comparison, the use of PiCCO was associated with a greater positive fluid balance and fewer ventilator-free days. After correction for confounding factors, the choice of monitoring did not influence major outcomes, whereas a positive fluid balance was a significant independent predictor of outcome. Future studies may best be targeted at understanding the effect of pursuing different fluid balance regimens rather than monitoring techniques per se.     

The effect of the arterial catheter insertion technique on the success of radial artery cannulation: A prospective and randomized study

Purpose

The main objective of the current investigation was to compare a single wall puncture to vessel transfixing on the success of radial artery cannulation by resident physicians.

Material and Methods

The study was a prospective and randomized investigation. Twelve anesthesiology residents performed radial arterial insertions in 126 patients using both the single wall and vessel transfixing technique in random order. The primary outcome was successful cannulation of the radial artery in 4 or less attempts. Other data collected included the total number of attempts and total time to catheter cannulation.

Results

Successful radial artery cannulation was achieved in 88% and 86% of patients using the transfixing technique and single wall group, respectively (difference 2%; 95% CI, 14-9, P = 0.8, Fisher exact test). Cannulation was successfully on the first attempt in 38% of the transfixing compared to 54% using the single wall technique (difference − 16%; 95% CI, 32-2, P = 0.1, Fisher Exact test). The median (interquartile range) time to successful cannulation was longer in the transfixing group, 105 (69-176) seconds compared to 65 (25-114) seconds in the single puncture group (P = .009, log-rank test).

Conclusions

Our findings suggest that there does not appear to be an advantage of the transfixing technique over the single wall puncture method for cannulating the radial artery by resident physicians. Cannulation was achieved in shorter time using the single wall puncture technique even after accounting for differences between residents and prior levels of experience.     

Air embolism and cardiac arrest in a patient with a pulmonary artery catheter: a possible association

This patient with acute mitral insufficiency suddenly developed hemoptysis and electromechanical dissociation. A post mortem chest X-ray demonstrated a large amount of air in the right ventricular cavity. It is postulated that this air embolism resulted from a catheter-induced rupture of the pulmonary artery.     

Continuous cardiac output measurement by un-calibrated pulse wave analysis and pulmonary artery catheter in patients with septic shock

Septic shock is a serious medical condition. With increased concerns about invasive techniques, a number of non-invasive and semi-invasive devices measuring cardiac output (CO) have become commercially available. The aim of the present study was to determine the accuracy, precision and trending abilities of the FloTrac and the continuous pulmonary artery catheter thermodilution technique determining CO in septic shock patients. Consecutive septic shock patients were included in two centres and CO was measured every 4 h up to 48 h by FloTrac (APCO) and by pulmonary artery catheter (PAC) using the continuous (CCO) and intermittent (ICO) technique. Forty-seven septic shock patients with 326 matched sets of APCO, CCO and ICO data were available for analysis. Bland and Altman analysis revealed a mean bias ±2 SD of 0.0 ± 2.14 L min^?1 for APCO–ICO (%error = 34.5 %) and 0.23 ± 2.55 L min^?1 for CCO–ICO (%error = 40.4 %). Trend analysis showed a concordance of 85 and 81 % for APCO and CCO, respectively. In contrast to CCO, APCO was influenced by systemic vascular resistance and by mean arterial pressure. In septic shock patients, APCO measurements assessed by FloTrac but also the established CCO measurements using the PAC did not meet the currently accepted statistical criteria indicating acceptable clinical performance.     

Microbiologic surveillance through subglottic secretion cultures during invasive mechanical ventilation: a prospective observational study

PurposeWhether subglottic secretions (SS) culture during invasive mechanical ventilation may aid microbiological surveillance is unknown. We conducted a prospective study to assess SS cultures predictivity of endotracheal aspirate (ETA) and bronchoalveolar lavage (BAL) isolates.Materials and methods109 patients receiving mechanical ventilation for ≥48 hours underwent SS and ETA surveillance cultures twice weekly; blind BAL was performed in case of clinically suspected pneumonia.ResultsSS and ETA cultures were fully concordant in 170 (81%-overall accuracy) of 211 sample pairs. As compared to ETA, SS culture global sensitivity and specificity were 84% [95%CI: 77 to 91] and 74% [95%CI: 66 to 82]; negative and positive predictive values were 82% and 77%. Forty-four episodes of clinically suspected pneumonia were observed. Compared to BAL, SS culture global sensitivity and specificity were 68% [95%CI: 45 to 81] and 63% [95%CI: 44 to 82]; negative and positive predictive values were both 65%. SS sensitivity, specificity, positive and negative predictive values in anticipating BAL isolates were comparable to ETA (all p > 0.20).ConclusionsSS cultures show worthy accuracy in identifying ETA isolates, with excellent sensitivity and good negative predictivity. SS cultures may be not inferior to ETA in predicting BAL results in case of ventilator-associated pneumonia.Trial registration: ClinicalTrials.gov, NCT03153241. Registered on 15 May 2017, https://clinicaltrials.gov/ct2/show/NCT03153241