A review of hemodynamic monitoring techniques, methods and devices for the emergency physician

Invasive Arterial BP Measurements in the Emergency Department-When, if Ever, is it Indicated?

PURPOSE OF REVIEW

Extremes of blood pressure (BP) are common among patients that visit emergency departments. In this review article, we discuss the specific indications for invasive blood pressure monitoring in the ED, particularly in the context of undifferentiated shock and hypertensive emergencies.

RECENT FINDINGS

In most cases, non-invasive techniques suffice for blood pressure monitoring, however, in certain patient presentations intermittent automated oscillometry bears significant drawbacks. The most evident drawback is the extended intervals between measurements. Invasive BP (IBP) monitoring offers a pivotal tool for patients with critical illness who require accurate, timely, blood pressure monitoring and indirectly monitors for complications involving vital organ systems. In the management of patients with critical illness or at risk for end organ injury, invasive methods that directly measure BP via arterial cannulation continues to be an established standard. Overall, evaluating patients on an individual basis, with the understanding that patients who present with extreme blood pressure values need closer monitoring, should prompt consideration of invasive methods of blood pressure monitoring.

Decrease of haemoconcentration reliably detects hydrostatic pulmonary oedema in dyspnoeic patients in the emergency department - a machine learning approach

BACKGROUND

Haemoglobin variation (ΔHb) induced by fluid transfer through the intestitium has been proposed as a useful tool for detecting hydrostatic pulmonary oedema (HPO). However, its use in the emergency department (ED) setting still needs to be determined.

METHODS

In this observational retrospective monocentric study, ED patients admitted for acute dyspnoea were enrolled. Hb values were recorded both at ED presentation (T0) and after 4 to 8 h (T1). ΔHb between T1 and T0 (ΔHbT1-T0) was calculated as absolute and relative value. Two investigators, unaware of Hb values, defined the cause of dyspnoea as HPO and non-HPO. ΔHbT1-T0 ability to detect HPO was evaluated. A machine learning approach was used to develop a predictive tool for HPO, by considering the ability of ΔHb as covariate, together with baseline patient characteristics.

RESULTS

Seven-hundred-and-six dyspnoeic patients (203 HPO and 503 non-HPO) were enrolled over 19 months. Hb levels were significantly different between HPO and non-HPO patients both at T0 and T1 (p < 0.001). ΔHbT1-T0 were more pronounced in HPO than non-HPO patients, both as relative (-8.2 [-11.2 to -5.6] vs. 0.6 [-2.1 to 3.3] %) and absolute (-1.0 [-1.4 to -0.8] vs. 0.1 [-0.3 to 0.4] g/dL) values (p < 0.001). A relative ΔHbT1-T0 of -5% detected HPO with an area under the receiver operating characteristic curve (AUROC) of 0.901 [0.896-0.906]. Among the considered models, Gradient Boosting Machine showed excellent predictive ability in identifying HPO patients and was used to create a web-based application. ΔHbT1-T0 was confirmed as the most important covariate for HPO prediction.

CONCLUSIONS

ΔHbT1-T0 in patients admitted for acute dyspnoea reliably identifies HPO in the ED setting. The machine learning predictive tool may represent a performing and clinically handy tool for confirming HPO.

Dynamic monitoring tools for patients admitted to the emergency department with circulatory failure: narrative review with panel-based recommendations

Intravenous fluid therapy is commonly administered in the emergency department (ED). Despite the deleterious potential of over- and under-resuscitation, professional society guidelines continue to recommend administering a fixed volume of fluid in initial resuscitation. Predicting whether a specific patient will respond to fluid therapy remains one of the most important, but challenging questions that ED clinicians face in clinical practice. Surrogate parameters (i.e. blood pressure and heart rate), are widely used in usual care to estimate changes in stroke volume (SV). Due to their inadequacy in estimating SV, noninvasive techniques (e.g. bioreactance, echocardiography, noninvasive finger cuff technology), have been proposed as a more accurate and readily deployable method for assessing flow and preload responsiveness. Dynamic monitoring systems based on cardiac preload challenge and assessment of SV, by using noninvasive and continuous methods, provide more accurate, feasible, efficient, and reasonably accurate strategy for prediction of fluid responsiveness than static measurements. In this article, we aimed to analyze the different methods currently available for dynamic monitoring of preload responsiveness.

A Population-Informed Particle Filter for Robust Physiological Monitoring Using Low-Information Time-Series Measurements

OBJECTIVE

To present the population-informed particle filter (PIPF), a novel filtering approach that incorporates past experiences with patients into the filtering process to provide reliable beliefs about a new patient's physiological state.

METHODS

To derive the PIPF, we formulate the filtering problem as recursive inference on a probabilistic graphical model, which includes representations for the pertinent physiological dynamics and the hierarchical relationship between past and present patient characteristics. Then, we provide an algorithmic solution to the filtering problem using Sequential Monte-Carlo techniques. To demonstrate the merits of the PIPF approach, we apply it to a case study of physiological monitoring for hemodynamic management.

RESULTS

The PIPF approach could provide reliable beliefs about the likely values and uncertainties associated with a patient's unmeasured physiological variables (e.g., hematocrit and cardiac output), characteristics (e.g., tendency for atypical behavior), and events (e.g., hemorrhage) given low-information measurements.

CONCLUSION

The PIPF shows promise in the presented case study, and may have applications to a wider range of real-time monitoring problems with limited measurements.

SIGNIFICANCE

Forming reliable beliefs about a patient's physiological state is an essential aspect of algorithmic decision-making in medical care settings. Hence, the PIPF may serve as a solid basis for designing interpretable and context-aware physiological monitoring, medical decision-support, and closed-loop control algorithms.

Value of variation of end-tidal carbon dioxide for predicting fluid responsiveness during the passive leg raising test in patients with mechanical ventilation: a systematic review and meta-analysis

Background

The ability of end-tidal carbon dioxide (ΔEtCO2) for predicting fluid responsiveness has been extensively studied with conflicting results. This meta-analysis aimed to explore the value of ΔEtCO2 for predicting fluid responsiveness during the passive leg raising (PLR) test in patients with mechanical ventilation.

Methods

PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched up to November 2021. The diagnostic odds ratio (DOR), sensitivity, and specificity were calculated. The summary receiver operating characteristic curve was estimated, and the area under the curve (AUROC) was calculated. Q test and I² statistics were used for study heterogeneity and publication bias was assessed by Deeks’ funnel plot asymmetry test. We performed meta-regression analysis for heterogeneity exploration and sensitivity analysis for the publication bias.

Results

Overall, six studies including 298 patients were included in this review, of whom 149 (50%) were fluid responsive. The cutoff values of ΔEtCO2 in four studies was 5%, one was 5.8% and the other one was an absolute increase 2 mmHg. Heterogeneity between studies was assessed with an overall Q = 4.098, I² = 51%, and P = 0.064. The pooled sensitivity and specificity for the overall population were 0.79 (95% CI 0.72–0.85) and 0.90 (95% CI 0.77–0.96), respectively. The DOR was 35 (95% CI 12–107). The pooled AUROC was 0.81 (95% CI 0.77–0.84). On meta-regression analysis, the number of patients was sources of heterogeneity. The sensitivity analysis showed that the pooled DOR ranged from 21 to 140 and the pooled AUC ranged from 0.92 to 0.96 when one study was omitted.

Conclusions

Though the limited number of studies included and study heterogeneity, our meta-analysis confirmed that the ΔEtCO2 performed moderately in predicting fluid responsiveness during the PLR test in patients with mechanical ventilation.

Development and internal validation of the HIV In-hospital Mortality Prediction (HIV-IMP) risk score

BACKGROUND

Despite advances in availability and access to antiretroviral therapy (ART), HIV still ranks as a major cause of global mortality. Hence, the aim of this study was to develop and internally validate a risk score capable of accurately predicting in-hospital mortality in HIV-positive patients requiring hospital admission.

METHODS

Consecutive HIV-positive patients presenting to the Charlotte Maxeke Johannesburg Academic Hospital adult emergency department between 7 July 2017 and 18 October 2018 were prospectively enrolled. Multivariate logistic regression was used to determine parameters for inclusion in the final risk score. Discrimination and calibration were assessed by means of the area under the receiver operating curve (AUROC) and the Hosmer-Lemeshow goodness-of-fit test, respectively. Internal validation was conducted using the regular bootstrap technique.

RESULTS

The overall in-hospital mortality rate was 13.6% (n = 166). Eight predictors were included in the final risk score: ART non-adherence or not yet on ART, Glasgow Coma Scale < 15, respiratory rate > 20 breaths/min, oxygen saturation < 90%, white cell count < 4 × 10⁹ /L, creatinine > 120 μmol/L, lactate > 2 mmol/L and albumin < 35 g/L. After internal validation, the risk score maintained good discrimination [AUROC 0.83, 95% confidence interval (CI): 0.78-0.88] and calibration (Hosmer-Lemeshow χ² = 2.26, p = 0.895).

CONCLUSION

The HIV In-hospital Mortality Prediction (HIV-IMP) risk score has overall good discrimination and calibration and is relatively easy to use. Further studies should be aimed at externally validating the score in varying clinical settings.

Relationship between Augmentation Index and Wall Thickening Fraction during Hypotension in an Animal Model of Myocardial Ischemia-Reperfusion and Heart Failure

AIMS

Non-invasive indices to evaluate left ventricular changes during ischemic heart failure are needed to quantify the myocardial impairment and the effectiveness of therapeutic manoeuvres. The aims of this work were to calculate the Wall Thickening Fraction (WTF) and the Augmentation Index (AIx) and to assess the relationship between WTF and AIx using data obtained from an animal model with heart failure followed by a myocardial ischemia stage and a reperfusion stage.

METHODS

Nine Corriedale sheep that had been monitored for 10 minutes during a basal stage underwent 5-minute myocardial ischemia, followed by 60-minute reperfusion. Seven of them were subjected to an induced heart failure through an overdose of halothane, two of which were treated with intra-aortic counterpulsation during the reperfusion stage. The remaining two animals were monitored during their ischemia-reperfusion stage.

RESULTS

Data obtained in the 5 animals suffering from heart failure followed by myocardial ischemia showed that: a) heart failure induction determined decrease in cardiac output, cardiac index and systolic and diastolic aortic pressure (AoP) with respect to their basal values (p<0.05), b) myocardial ischemia decreased the WTF compared with basal and induced heart failure values (p<0.05), c) during the reperfusion stage accompanied by induced heart failure, WTF increased with respect to values observed during the ischemia induction stage (p<0.05); nevertheless, basal values were not recovered after reperfusion (p<0.05). During this 60-minute stage, systolic and diastolic AoP values were lower (p<0.05) than those at the basal stage.

CONCLUSION

AIx and WTF values calculated from synchronically recorded values of aortic pressure and left ventricular wall thickness during the reperfusion stage in all animals (n = 9) showed a negative correlation (p<0.05). Analysed data provided evidence of a negative relationship between a left ventricular index of myocardial function and an arterial index obtained from AoP waves.

Point-of-care ultrasound stewardship

Rapid adoption and widespread use of point-of-care ultrasound (POCUS) has impacted diagnostic testing and clinical care across medical disciplines. The benefits of POCUS must be weighed against certain pitfalls, such as the risk of misdiagnosis and false assurance. Beyond technical error in image acquisition and interpretation, an important pitfall is reliance on POCUS results without considering pre-test patient characteristics or the diagnostic accuracy of POCUS in varying clinical contexts. In this article, we introduce the concept of POCUS stewardship that emphasizes critical evaluation of clinical indications prior to performing POCUS as well as the individual patient and test characteristics of POCUS when integrating results into clinical decisionmaking. Adherence to these principles can lead to optimized POCUS application and improved patient care.

Return of spontaneous circulation in patients with out-of-hospital cardiac arrest caused by pulmonary embolism using early point-of-care ultrasound and timely thrombolytic agent application: Two case reports

Introduction:

Acute pulmonary embolism is a confirmed cause of up to 5% of out-of-hospital cardiac arrest and 5%–13% of unexplained cardiac arrest in patients. However, the true incidence may be much higher, as pulmonary embolism is often clinically underdiagnosed. Thrombolytic therapy is a recognized therapy for pulmonary embolism–associated cardiac arrest but is not routinely recommended during cardiopulmonary resuscitation. Therefore, clinicians should attempt to identify patients with suspected pulmonary embolism. Many point-of care ultrasound protocols suggest diagnosis of pulmonary embolism for cardiac arrest patients.

Case presentation:

We describe two male patients (60 years and 66 years, respectively) who presented to the emergency department with cardiac arrest within a period of 1 week. With administration of point-of care ultrasound during the ongoing cardiopulmonary resuscitation in both patients, fibrinolytic therapy was initiated under suspicion of cardiac arrest caused by pulmonary embolism. Both patients had return of spontaneous circulation; however, only the second patient, who received fibrinolytic therapy relatively early, was discharged with a good outcome. In this report, we discussed how to diagnose and manage patients with cardiac arrest–associated pulmonary embolism with the help of point-of care ultrasound. We also discuss the different clinical outcomes of the two patients based on the experience of the clinicians and the timing of thrombolytic agent application.

Conclusions:

If acute pulmonary embolism is suspected in patients with out-of-hospital cardiac arrest, we recommend prompt point-of care ultrasound examination. Point-of care ultrasound may help identify patients with pulmonary embolism during cardiopulmonary resuscitation, leading to immediate treatment, although the clinical outcomes may vary.

Emergency department non-invasive cardiac output study (EDNICO): an accuracy study

BACKGROUND

There is little published data investigating non-invasive cardiac output monitoring in the emergency department (ED). We assess here the accuracy of five non-invasive methods in detecting fluid responsiveness in the ED: (1) common carotid artery blood flow, (2) suprasternal aortic Doppler, (3) bioreactance, (4) plethysmography with digital vascular unloading method, and (5) inferior vena cava collapsibility index. Left ventricular outflow tract echocardiography derived velocity time integral is the reference standard. This follows an assessment of feasibility and repeatability of these methods in the same cohort of ED patients.

METHODS

This is a prospective observational study of non-invasive methods for assessing fluid responsiveness in the ED. Participants were non-ventilated ED adult patients requiring intravenous fluid resuscitation. Sensitivity and specificity of each method in determining the fluid responsiveness status of participants is determined in comparison to the reference standard.

RESULTS

Thirty-three patient data sets were included for analysis. The specificity and sensitivity to detect fluid responders was 46.2 and 45% for common carotid artery blood flow (CCABF), 61.5 and 63.2% for suprasternal artery Doppler (SSAD), 46.2 and 50% for bioreactance, 50 and 41.2% for plethysmography vascular unloading technique (PVUT), and 63.6 and 47.4% for inferior vena cava collapsibility index (IVCCI), respectively. Analysis of agreement with Cohen's Kappa - 0.08 for CCABF, 0.24 for SSAD, - 0.04 for bioreactance, - 0.08 for PVUT, and 0.1 for IVCCI.

CONCLUSION

In this study, non-invasive methods were not found to reliably identify fluid responders. Non-invasive methods of identifying fluid responders are likely to play a key role in improving patient outcome in the ED in fluid depleted states such as sepsis. These results have implications for future studies assessing the accuracy of such methods.

[Hypovolemic and hemorrhagic shock]

The term "shock" refers to a life-threatening circulatory failure caused by an imbalance between the supply and demand of cellular oxygen. Hypovolemic shock is characterized by a reduction of intravascular volume and a subsequent reduction in preload. The body compensates the loss of volume by increasing the stroke volume, heart frequency, oxygen extraction rate, and later by an increased concentration of 2,3-diphosphoglycerate with a rightward shift of the oxygen dissociation curve. Hypovolemic hemorrhagic shock impairs the macrocirculation and microcirculation and therefore affects many organ systems (e.g. kidneys, endocrine system and endothelium). For further identification of a state of shock caused by bleeding, vital functions, coagulation tests and hematopoietic procedures are implemented. Every hospital should be in possession of a specific protocol for massive transfusions. The differentiated systemic treatment of bleeding consists of maintenance of an adequate homeostasis and the administration of blood products and coagulation factors.

Emergency department non-invasive cardiac output study (EDNICO): a feasibility and repeatability study

Background

There is little published data investigating non-invasive cardiac output monitoring in the emergency department (ED). We assessed six non-invasive fluid responsiveness monitoring methods which measure cardiac output directly or indirectly for their feasibility and repeatability of measurements in the ED: (1) left ventricular outflow tract echocardiography derived velocity time integral, (2) common carotid artery blood flow, (3) suprasternal aortic Doppler, (4) bioreactance, (5) plethysmography with digital vascular unloading method, and (6) inferior vena cava collapsibility index.

Methods

This is a prospective observational study of non-invasive methods of assessing fluid responsiveness in the ED. Participants were non-ventilated ED adult patients requiring intravenous fluid resuscitation. Feasibility of each method was determined by the proportion of clinically interpretable measurements from the number of measurement attempts. Repeatability was determined by comparing the mean difference of two paired measurements in a fluid steady state (after participants received an intravenous fluid bolus).

Results

76 patients were recruited in the study. A total of 207 fluid responsiveness measurement sets were analysed. Feasibility rates were 97.6% for bioreactance, 91.3% for vascular unloading method with plethysmography, 87.4% for common carotid artery blood flow, 84.1% for inferior vena cava collapsibility index, 78.7% for LVOT VTI, and 76.8% for suprasternal aortic Doppler. The feasibility rates difference between bioreactance and all other methods was statistically significant.

Conclusion

Our study shows that non-invasive fluid responsiveness monitoring in the emergency department may be feasible with selected methods. Higher repeatability of measurements were observed in non-ultrasound methods. These findings have implications for further studies specifically assessing the accuracy of such non-invasive cardiac output methods and their effect on patient outcome in the ED in fluid depleted states such as sepsis.

Electronic supplementary material

The online version of this article (10.1186/s13049-019-0586-6) contains supplementary material, which is available to authorized users.

Reference intervals and percentile curve for left ventricular outflow tract (LVOT), velocity time integral (VTI), and LVOT-VTI-derived hemodynamic parameters in healthy children and adolescents: Analysis of echocardiographic methods association and agreement

BACKGROUND

Echocardiographic reference intervals (RIs) for left ventricular outflow tract (LVOT) and velocity time integral (VTI) are scarce in pediatrics.

AIMS

(a) to generate RIs and percentiles for LVOT, VTI, and hemodynamic variables in healthy children and adolescents from Argentina; (b) to analyze the equivalence between stroke volume (SV), cardiac output (CO), and cardiac index (CI) obtained from two-dimensional echocardiography (2D) and LVOT-VTI analysis with pulsed wave Doppler (PWD); and (c) to analyze the association between subjects' characteristics and VTI and LVOT-VTI-derived parameters.

METHODS

Two-dimensional and PWD studies were done in 385 subjects (5-24 years). Mean and standard deviation age-related and body surface area (BSA)-related equations were obtained for VTI and LVOT-VTI-derived parameters (parametric regression methods based on fractional polynomials). BSA- and age-specific percentiles were determined.

RESULTS

Pulsed wave Doppler- and 2D-derived parameters were positively correlated. However, PWD values were always lower than those from 2D. Specific RIs for PWD and 2D data were necessary. Covariance analysis showed that sex-specific RIs were required for LVOT, but not for VTI, VTI-derived CO and CI. Age-related RIs were obtained for LVOT, LVOT-VTI, and VTI-derived CO and CI. BSA-related RIs for VTI-derived CO and CI were obtained.

CONCLUSIONS

Stroke volume, CO, and CI data from 2D and PWD are not equivalent. An accurate analysis of LVOT-VTI-derived parameters requires considering age and BSA. In this study, age- and BSA-related RIs and percentiles for LVOT, VTI, and hemodynamic parameters in healthy children and adolescents were determined, discriminating data according to the methodological approach (2D or PWD).

Point-of-Care Ultrasound Identifies Decompensated Heart Failure in a Young Male with Methamphetamine-Associated Cardiomyopathy Presenting in Severe Sepsis to the Emergency Department

We describe a case of a young male who presents to the emergency department with severe sepsis and decompensated heart failure with underlying Methamphetamine-Associated Cardiomyopathy that was previously undiagnosed. This presentation is unique because Methamphetamine-Associated Cardiomyopathy is an uncommonly reported condition that presented in a complex clinical scenario of severe sepsis and decompensated congestive heart failure. We discuss how we used point-of-care ultrasound (POCUS) in this case to identify an unsuspected disease process and how it changed our initial resuscitation strategy and management. Emergency physicians can utilize point-of-care ultrasound (POCUS) to help identify these high-risk patients in the emergency department and guide appropriate resuscitation. Methamphetamine-Associated Cardiomyopathy (MAC) is an infrequently described complication of methamphetamine abuse, most commonly presented as a nonischemic dilated cardiomyopathy. With the rise in methamphetamine abuse in the United States, complications from methamphetamine use are more commonly presenting to the emergency department. Proper education and rehabilitation, with a goal of abstinence from amphetamine use, may allow patients to potentially regain normal cardiac function. Since the majority of patients present late with severe cardiac dysfunction, early detection is essential amongst critically ill patients since recognition may significantly influence ED management.

Current Use of Invasive and Noninvasive Monitors in Academic Pediatric Intensive Care Units

To describe the current use of noninvasive monitoring compared with traditional invasive monitoring in Pediatric Critical Care Medicine (PCCM) accredited fellowship programs in the United States. A web-based survey with the primary aim of describing the utilization of noninvasive monitoring compared with invasive monitoring was distributed to PCCM program directors (PDs) at the 64 accredited fellowship training programs. Questions focused on demographics and the utilization of invasive and noninvasive monitoring for specific patient populations and disease states. Forty-two (66%) PDs responded to the survey. Capnography and near-infrared spectroscopy (NIRS) were the most commonly reported noninvasive monitoring technology. Arterial and central venous catheters were widely used. Other invasive monitoring devices were used sparingly. Despite widespread use of both invasive and noninvasive monitoring in academic pediatric critical care units across the United States, there is significant variability in the use of noninvasive monitoring compared with invasive monitoring. Further investigation is needed to define the standard of care for the use of noninvasive monitors as practitioners attempt to optimize care while minimizing risks and complications.

Accuracy of Ultrasonographic Measurements of Inferior Vena Cava to Determine Fluid Responsiveness: A Systematic Review and Meta-Analysis

OBJECTIVE

Fluid responsiveness is the ability to increase the cardiac output in response to a fluid challenge. Only about 50% of patients receiving fluid resuscitation for acute circulatory failure increase their stroke volume, but the other 50% may worsen their outcome. Therefore, predicting fluid responsiveness is needed. In this purpose, in recent years, the assessment of the inferior vena cava (IVC) through ultrasound (US) has become very popular. The aim of our work was to systematically review all the previously published studies assessing the accuracy of the diameter of IVC or its respiratory variations measured through US in predicting fluid responsiveness.

DATA SOURCES

We searched in the MEDLINE (PubMed), Embase, Web of Science databases for all relevant articles from inception to September 2017.

STUDY SELECTION

Included articles specifically addressed the accuracy of IVC diameter or its respiratory variations assessed by US in predicting the fluid responsiveness in critically ill ventilated or not, adult or pediatric patients.

DATA EXTRACTION

We included 26 studies that investigated the role of the caval index (IVC collapsibility or distensibility) and 5 studies on IVC diameter.

DATA SYNTHESIS

We conducted a meta-analysis for caval index with 20 studies: The pooled area under the curve, logarithmic diagnostic odds ratio, sensitivity, and specificity were 0.71 (95% confidence interval [CI]: 0.46-0.83), 2.02 (95% CI: 1.29-2.89), 0.71 (95% CI: 0.62-0.80), and 0.75 (95% CI: 0.64-0.85), respectively.

CONCLUSION

An extreme heterogeneity of included studies was highlighted. Ultrasound evaluation of the diameter of the IVC and its respiratory variations does not seem to be a reliable method to predict fluid responsiveness.

Cardiac arrest due to pulmonary embolism

Pulmonary embolism (PE) is a potentially life threatening clinical condition that is fairly non-specific in presentation. Massive pulmonary embolism (PE) without cardiac arrest has been associated with a mortality rate of 30%. However, when cardiac arrest ensues, mortality may be as high as 95%. Since outcomes of cardiac arrest following PE are generally dismal, any available potentially life-saving measure must be instituted when the diagnosis of PE is suspected. Despite a lack of randomized controlled trials guiding the management of suspected PE in the cardiac arrest victim, thrombolysis and other therapies have been associated with good outcomes in the handful of published case reports and other small studies.

The PCQP Score for Volume Status of Acutely Ill Patients: Integrating Vascular Pedicle Width, Caval Index, Respiratory Variability of the QRS Complex and R Wave Amplitude

Introduction

Techniques for measuring volume status of critically ill patients include invasive, less invasive, or noninvasive ones. The present study aims to assess the accuracy of noninvasive techniques for measuring volume status of critically ill patients.

Patients and Methods

A total of 111 critically ill patients admitted to the emergency department and undergoing central venous catheterization were included in the study. Five parameters were measured including vascular pedicle width (VPW), diameter of inferior vena cava, caval index, respiratory changes in QRS, and P wave amplitude. Patients with risk factors which could decrease the accuracy of central venous pressure (CVP) value were excluded from study. We compared these parameters with static CVP parameter. Finally, based on the afore-mentioned parameters, PCQP role in criteria was designed.

Results

In detecting loss of circulating blood volume, area under the curve of VPW was 0.92 (90%, confidence interval [CI]: 0.85-0.99), diameter of inferior vena cava was 0.82 (90%, CI: 0.72-0.91), caval index was 0.9 (90%, CI: 0.82-0.98), and changes in QRS and P waves were 0.88 (95%, CI: 0.81-0.95) and 0.73 (95%, CI: 0.63-0.82), respectively. PCQP role in criteria was designed according to these parameters, and at its best cutoff point (score 6), VPW had a sensitivity of 97.4% (95%, CI: 84.57-99.99) and specificity of 83.6% (95%, CI: 72.65-90.86) for the detection of loss of circulating blood volume (<8 cmH₂O).

Conclusion

PCQP score could be a reliable and noninvasive technique for the assessment of volume status in critically ill patients.