Emergency department noninvasive (NICOM) cardiac outputs are associated with trauma activation, patient injury severity and host conditions and mortality

Ward based goal directed fluid therapy (GDFT) in acute pancreatitis (GAP) trial: A feasibility randomised controlled trial

BACKGROUND

Goal-directed fluid therapy (GDFT) reduces complications in patients undergoing major general surgery. There are no reports of cardiac output evaluation being used to optimise the fluid administration for patients with acute pancreatitis (AP) in a general surgery ward.

METHOD

50 patients with AP were randomised to either ward-based GDFT (n = 25) with intravenous (IV) fluids administered based on stroke volume optimisation protocol or standard care (SC) (n = 25), but with blinded cardiac output evaluation, for 48-h following hospital admission. Primary outcome was feasibility.

RESULTS

50 of 116 eligible patients (43.1%) were recruited over 20 months demonstrating feasibility. 36 (72%) completed the 48-h of GDFT; 10 (20%) discharged within 48-h and 4 withdrawals (3 GDFT, 1 SC). Baseline characteristics were similar with only 3 participants having severe disease (6%, 1 GDFT, 2 SC). Similar volumes of IV fluids were administered in both groups (GDFT 5465 (1839) ml, SC 5211 (1745) ml). GDFT group had a lower heart rate, blood pressure and respiratory rate and improved oxygen saturations. GDFT was not associated with any harms. There was no evidence of difference in complications of AP (GDFT 24%, SC 32%) or in the duration of stay in intensive care (GDFT 0 (0), SC 0.7 [(Van DIjk et al., 2017) 33 days). Length of hospital stay was 5 (2.9) days in GDFT and 6.3 (7.6) in SC groups.

CONCLUSION

Ward-based GDFT is feasible and shows a signal of possible efficacy in AP in this early-stage study. A larger multi-site RCT is required to confirm clinical and cost effectiveness.

Updates in Hemodynamic Monitoring: A Review for Pharmacists

Vital signs are regularly monitored in hospitalized patients. In the intensive care unit (ICU), traditional non-invasive blood pressure monitoring and telemetry may not provide enough information to determine the etiology of hemodynamic instability or guide intervention. Arterial catheters remain the gold-standard for continuous blood pressure monitoring and are commonly used in ICU patients. Pulmonary artery catheters and central venous catheters are beneficial in select patient populations and provide more advanced and specific information about a patient's hemodynamics. However, neither are benign and can increase risk of complications such as infection, arrhythmias, pneumothorax and vascular or valvular damage. In the past 10 years, the development of reliable non-invasive (NICOM), or minimally-invasive (MICOM), cardiac output monitoring devices has accelerated. The MICOM devices require an arterial catheter to obtain hemodynamic values, whereas NICOM devices do not require any arterial or venous access. These devices have emerged to be particularly useful in evaluating and managing patients with suspected mixed shock. As these devices become more prevalent, it is imperative that clinical pharmacists become familiar with interpreting this data as it may have a substantial impact on medication selection and optimization. This review will discuss the basics of NICOM and MICOM devices, limitations with these methods of monitoring, and clinical application for pharmacists.

Early hemodynamic assessment using NICOM in patients at risk of developing Sepsis immediately after emergency department triage

Background

One factor leading to the high mortality rate seen in sepsis is the subtle, dynamic nature of the disease, which can lead to delayed detection and under-resuscitation. This study investigated whether serial hemodynamic parameters obtained from a non-invasive cardiac output monitor (NICOM) predicts disease severity in patients at risk for sepsis.

Methods

Prospective clinical trial of the NICOM device in a convenience sample of adult ED patients at risk for sepsis who did not have obvious organ dysfunction at the time of triage. Hemodynamic data were collected immediately following triage and 2 hours after initial measurement and compared in two outcome groupings: (1) admitted vs. dehydrated, febrile, hypovolemicdischarged patients; (2) infectious vs. non-infectious sources. Receiver operator characteristic (ROC) curves were calculated to determine whether the NICOM values predict hospital admission better than a serum lactate.

Results

50 patients were enrolled, 32 (64 %) were admitted to the hospital. Mean age was 49.5 (± 16.5) years and 62 % were female. There were no significant associations between changes in hemodynamic variables and patient disposition from the ED or diagnosis of infection. Lactate was significantly higher in admitted patients and those with infection (p = 0.01, p = 0.01 respectively). The area under the ROC [95 % Confidence Intervals] for lactate was 0.83 [0.64–0.92] compared to 0.59 [0.41–0.73] for cardiac output (CO), 0.68 [0.49–0.80] for cardiac index (CI), and 0.63 [0.36–0.80] for heart rate (HR) for predicting hospital admission.

Conclusions

CO and CI, obtained at two separate time points, do not help with early disease severity differentiation of patients at risk for severe sepsis. Although mean HR was higher in those patients who were admitted, a serum lactate still served as a better predictor of patient admission from the ED.

Comparison of cardiac output, IVC diameters and lactate levels in prediction of mortality in patients in emergency department; An observational study

Objective:

Fluid overload is an independent marker for mortality in critically ill patients. Assessment of fluid status and fluid responsiveness is crucial for the management of these patients. In this study, we compared the lactate level, inferior vena cava (IVC) diameter and non-invasive cardiac output (CO) monitoring in prediction of mortality in emergency department.

Methods:

This was a cross sectional observational study which comprised of 68 patients and was performed in ED of Tabriz University of Medical Sciences, Iran, from Sept 2016 until Sept 2017. IVC diameter was measured before the P-wave on ECG to avoid interference with a-wave and v-wave on the venous pressure curve, and during maximal inspiration and expiration to avoid Valsalva-like maneuvers. An arterial lactate sample was taken from all patients before performing the initial resuscitation. All patients underwent non-invasive CO monitoring by CO₂ rebreathing technique. Mortality was noted on day 28.

Results:

Deceased patients had a significantly low level of IVC diameters, less CO values and more lactate levels. However, based on ROC curve analysis, the prediction accuracy and validity of both CO values obtained by rebreathing CO₂ and IVC diameter was poor and the highest accuracy was obtained by lactate level assessment.

Conclusion:

Initial lactate value is a reliable parameter for prediction of mortality in non-traumatic critically ill patients. IVC diameter changes during spontaneous ventilation and non-invasive CO monitoring does not possess acceptable accuracy for prediction of mortality in these patients.

Ward-based Goal-Directed Fluid Therapy (GDFT) in Acute Pancreatitis (GAP) trial: study protocol for a feasibility randomised controlled trial

INTRODUCTION

Acute pancreatitis is an inflammatory disease of the pancreas with high risk of developing multiorgan failure and death. There are no effective pharmacological interventions used in current clinical practice. Maintaining fluid and electrolyte balance is the mainstay of supportive management. Goal-directed fluid therapy (GDFT) has been shown to decrease morbidity and mortality in surgical conditions with systemic inflammatory response. There is currently no randomised controlled trial (RCT) investigating the role of GDFT based on cardiac output parameters in patients with acute pancreatitis in the ward setting. A feasibility trial was designed to determine patient and clinician support for recruitment into an RCT of ward-based GDFT in acute pancreatitis, adherence to a GDFT protocol, safety, participant withdrawal, and to determine appropriate endpoints for a subsequent larger trial to evaluate efficacy.

METHODS AND ANALYSIS

The GDFT in Acute Pancreatitis trial is a prospective two-centre feasibility RCT. Eligible adults admitted with new onset of acute pancreatitis will be enrolled and randomised into ward-based GDFT (n=25) or standard fluid therapy (n=25) within 6 hours from the diagnosis and continuing for the following 48 hours. Cardiac output parameters will be monitored with a non-invasive device (Cheetah NICOM; Cheetah Medical). The intervention group will consist of a protocolised GDFT approach consisting of stroke volume optimisation with crystalloid fluid boluses, while the control group will receive standard care fluid therapy as advised by the clinical team. The primary endpoint is feasibility. Secondary endpoints will include safety of the intervention, complications, mortality, admission to intensive care unit, cost and quality of life.

ETHICS AND DISSEMINATION

Ethics approval was granted by the London Central Research Ethics Committee (17/LO/1235, project ID: 221872). The results of this trial will be presented to international conference with interest in general surgery and acute care and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ISRCTN36077283.

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.

Non-invasive cardiac output monitoring device "ICON" in trauma patients: a feasibility study

PURPOSE

Assessment of hemodynamics is crucial for the evaluation of major trauma patients. Cardiac output (CO) monitoring provides additional information and may improve volume resuscitation. The goal of this prospective pilot study was to evaluate the feasibility of a new non-invasive CO monitoring (NICOM) device in the emergency department (ED).

METHODS

Single-center prospective observational pilot study including 20 trauma patients admitted to a level 1 trauma center. CO was continuously monitored for 60 min after ED admission using the new NICOM device ICON^®. This device measures changes of the thoracic bioimpedance to calculate CO. Conventional vital signs were recorded simultaneously. Feasibility, safety, reliability, user-friendliness, and impact of the device on standard ED procedures were assessed.

RESULTS

Thirteen (65%) patients were male, median age was 57.5 (IQR 25), and median ISS was 10.5 (IQR 14.8). Median CO over time was 9.8 l/min (IQR 4.6). No adverse effects were recorded. The device proved to be user-friendly with no negative impact on routine ED care. In four patients, detachment of electrodes was observed, and in four patients, the CO recording was temporary discontinued. Short-term changes of the CO were observed 44 times after the placement of electrodes and during patient transfers.

CONCLUSIONS

Non-invasive CO monitoring proved to be feasible and safe for the initial hemodynamic evaluation of trauma patients. Problems with the NICOM device were detachment of electrodes and temporary signal loss. Due to the small sample size and relatively low injury burden of the patients included in this study, further prospective investigation is warranted.

The Evolving Science of Trauma Resuscitation

This review summarizes the evolution of trauma resuscitation from a one-size-fits-all approach to one tailored to patient physiology. The most dramatic change is in the management of actively bleeding patients, with a balanced blood product-based resuscitation approach (avoiding crystalloids) and surgery focused on hemorrhage control, not definitive care. When hemostasis has been achieved, definitive resuscitation to restore organ perfusion is initiated. This approach is associated with decreased mortality, reduced duration of stay, improved coagulation profile, and reduced crystalloid/vasopressor use. This article focuses on the tools and methods used for trauma resuscitation in the acute phase of trauma care.

Comparison of stroke volume measurement between non-invasive bioreactance and esophageal Doppler in patients undergoing major abdominal-pelvic surgery

PURPOSE

Bioreactance is a non-invasive technology for measuring stroke volume (SV) in the operating room and critical care setting. We evaluated how the NICOM^® bioreactance device performed against the CardioQ^® esophageal Doppler monitor in patients undergoing major abdominal-pelvic surgery, focusing on the effect of different hemodynamic interventions.

METHODS

SV_NICOM and SV_ODM were simultaneously measured intraoperatively, including before and after interventions including fluid challenge, vasopressor boluses, peritoneal gas insufflation/removal, and Trendelenburg/reverse Trendelenburg patient positioning.

RESULTS

A total of 768 values were collected from 21 patients. Pre- and post-intervention measures were recorded on 155 occasions. Bland-Altman analysis revealed a bias of 8.6 ml and poor precision with wide limits of agreement (54 and -37 ml) and a percentage error of 50.6%. No improvement in precision was detected after taking into account repeated measurements for each patient (bias: 8 ml; limits of agreement: 74 and -59 ml). Concordance between changes in SV_NICOM and SV_ODM before and after interventions was also poor: 78.7% (all measures), 82.4% (after vasopressor administration), and 74.3% (after fluid challenge). Using Doppler SV as the reference technique, the area under the receiver operating characteristic curve assessing the ability of the NICOM device to predict fluid responsiveness was 0.81 (0.7-0.9).

CONCLUSIONS

In patients undergoing major abdomino-pelvic surgery, SV values obtained by NICOM showed neither clinically or statistically acceptable agreement with those obtained by esophageal Doppler. Although, in the setting of this study, bioreactance technology cannot reliably replace esophageal Doppler monitoring, its accuracy for predicting fluid responsiveness was higher, up to approximately 80%.

TRIAL REGISTRATION

Observational study.

Blood pressure and heart rate from the arterial blood pressure waveform can reliably estimate cardiac output in a conscious sheep model of multiple hemorrhages and resuscitation using computer machine learning approaches

BACKGROUND

This study was a first step to facilitate the development of automated decision support systems using cardiac output (CO) for combat casualty care. Such systems remain a practical challenge in battlefield and prehospital settings. In these environments, reliable CO estimation using blood pressure (BP) and heart rate (HR) may provide additional capabilities for diagnosis and treatment of trauma patients. The aim of this study was to demonstrate that continuous BP and HR from the arterial BP waveform coupled with machine learning (ML) can reliably estimate CO in a conscious sheep model of multiple hemorrhages and resuscitation.

METHODS

Hemodynamic parameters (BPs, HR) were derived from 100-Hz arterial BP waveforms of 10 sheep records, 3 hours to 4 hours long. Two models (mean arterial pressure, Windkessel) were then applied and merged to estimate COVS. ML was used to develop a rule for identifying when models required calibration. All records contained 100-Hz recording of pulmonary arterial blood flow using Doppler transit time (COFP). COFP and COVS were analyzed using equivalence tests and Bland-Altman analysis, as well as waveform and concordance plots.

RESULTS

Baseline COFP varied from 3.0 L/min to 5.4 L/min, while posthemorrhage COFP varied from 1.0 L/min to 1.8 L/min. A total of 315,196 pairs of data were obtained. Equivalence tests for individual records showed that COVS was statistically equivalent to COFP (p < 0.05). Smaller equivalence thresholds (<0.3 L/min) indicated an overall high COFP accuracy. The agreement between COFP and COVS was -0.13 (0.69) L/min (Bland-Altman). In an exclusion zone of 12%, trending analysis found a 92% concordance between 5-minute changes in COFP and COVS.

CONCLUSION

This study showed that CO can be reliably estimated using BPs and HR from the arterial BP waveform in combination with ML. A next step will be to test this approach using noninvasive BPs and HR.

Non-invasive hemodynamic monitoring in trauma patients

BACKGROUND

The assessment of hemodynamic status is a crucial task in the initial evaluation of trauma patients. However, blood pressure and heart rate are often misleading, as multiple variables may impact these conventional parameters. More reliable methods such as pulmonary artery thermodilution for cardiac output measuring would be necessary, but its applicability in the Emergency Department is questionable due to their invasive nature. Non-invasive cardiac output monitoring devices may be a feasible alternative.

METHODS

A systematic literature review was conducted. Only studies that explicitly investigated non-invasive hemodynamic monitoring devices in trauma patients were considered.

RESULTS

A total of 7 studies were identified as suitable and were included into this review. These studies evaluated in a total of 1,197 trauma patients the accuracy of non-invasive hemodynamic monitoring devices by comparing measurements to pulmonary artery thermodilution, which is the gold standard for cardiac output measuring. The correlation coefficients r between the two methods ranged from 0.79 to 0.92. Bias and precision analysis ranged from -0.02 +/- 0.78 l/min/m(2) to -0.14 +/- 0.73 l/min/m(2). Additionally, data on practicality, limitations and clinical impact of the devices were collected.

CONCLUSION

The accuracy of non-invasive cardiac output monitoring devices in trauma patients is broadly satisfactory. As the devices can be applied very early in the shock room or even preclinically, hemodynamic shock may be recognized much earlier and therapeutic interventions could be applied more rapidly and more adequately. The devices can be used in the daily routine of a busy ED, as they are non-invasive and easy to master.

Noninvasive cardiac output monitoring using bioreactance-based technique in pediatric patients with or without ventricular septal defect during anesthesia: in comparison with echocardiography

BACKGROUND

We evaluated the use of bioreactance-based noninvasive cardiac output (CO) monitoring technique (NICOM(™), CO(NICOM)) in pediatric patients with or without ventricular septal defect (VSD) during anesthesia induction to determine its agreement with the measurements assessed by echocardiography (echo, CO(ECHO)).

METHODS

Twenty-eight pediatric patients with normal heart anatomy (group NHA) and 32 with isolated ventricular septal defects (group VSD) were included in this study. The cardiac output was measured simultaneously in minute-by-minute using NICOM and echo (Simpson's rule) during anesthesia induction and intubation. Linear regression and revised Bland-Altman analyses were performed to evaluate the agreement by comparing the paired CO results. The mean percent error ((CO(ECHO)-CO(NICOM))/CO(ECHO) × 100%) was used to assess the impact of congenital heart disease on the agreement.

RESULTS

The measurements of CO by NICOM and echo techniques were highly correlated in group NHA (γ = 0.96, P < 0.005) and VSD (γ = 0.84, P < 0.005). The mean bias (CO(ECHO) - CO(NICOM)) between the two methods was 0.03 and 0.31 l·min(-1) with the limits of agreement (LOA) -0.29 to +0.35 l·min(-1) and -0.44 to +1.05 l·min(-1), which include 96.9% (31/32) and 89.3% (25/28) of all patients' different data in group NHA and VSD, respectively. The median percent errors were significantly lower at all time points in group NHA than those in group VSD (all P < 0.05).

CONCLUSION

In children without heart defects, the CO measured by NICOM shows a good agreement with the echo during anesthesia induction. The NICOM technique underestimates echo although a strong correlation exists between two methods in children with ventricular septal defect.

Cardiovascular parameters in a mixed-sex swine study of severe decompression sickness treated with the emulsified perfluorocarbon Oxycyte

Intravenous perfluorocarbons (PFC) have reduced the effects of decompression sickness (DCS) and improved mortality rates in animal models. However, concerns for the physiological effects of DCS combined with PFC therapy have not been examined in a balanced mixed-sex population. Thirty-two (16 male, 16 female) instrumented and sedated juvenile Yorkshire swine were exposed to 200 feet of seawater (fsw) for 31 min of hyperbaric air. Pulmonary artery pressure (PAP), cardiac output (CO), and systemic arterial pressure (SAP) were monitored before (control) and after exposure. Animals were randomized to treatment with Oxycyte (5 ml/kg; Oxygen Biotherapeutics, Inc., Morrisville, NC) vs. saline (control) with 100% oxygen administered upon DCS onset; animals were observed for 90 min. Parameters recorded and analyzed included PAP, CO, and SAP. In all animals PAP began to rise prior to cutis marmorata (CM) onset, the first sign of clinical DCS, generally peaking after CM onset. Female swine, compared with castrated males, had a more rapid onset of CM (7.30 vs. 11.46 min postsurfacing) and earlier onset to maximal PAP (6.41 vs. 9.69 min post-CM onset). Oxycyte therapy was associated with a sustained PAP elevation above controls in both sexes (33.41 vs. 25.78 mmHg). Significant pattern differences in PAP, CO, and SAP were noted between sexes and between therapeutic groups. There were no statistically significant differences in survival or paralysis between the PFC and control groups during the 48-h observation period. In conclusion, Oxycyte therapy for DCS is associated with a prolonged PAP increase in swine. These species and sex differences warrant further exploration.

In emergently ventilated trauma patients, low end-tidal CO2 and low cardiac output are associated and correlate with hemodynamic instability, hemorrhage, abnormal pupils, and death

Background

In a smaller experience, the authors previously demonstrated that end-tidal carbon dioxide (PetCO₂) and cardiac output (CO) had a positive association in emergently intubated trauma patients during Emergency Department resuscitation. The aim of this larger study was to reassess the relationship of PetCO₂ with CO and identify patient risk-conditions influencing PetCO₂ and CO values.

Methods

The investigation consists of acutely injured trauma patients requiring emergency tracheal intubation. The study focuses on the prospective collection of PetCO₂ and noninvasive CO monitor (NICOM®) values in the Emergency Department.

Results

From the end of March through August 2011, 73 patients had 318 pairs of PetCO₂ (mm Hg) and CO (L/min.) values. Mean data included Injury Severity Score (ISS) ≥15 in 65.2%, Glasgow Coma Score of 6.4 ± 4.6, hypotension in 19.0%, and death in 34.3%. With PetCO₂ ≤ 25 (15.9 ± 8.0), systolic blood pressure was 77.0 ± 69, CO was 3.2 ± 3.0, cardiac arrest was 60.4%, and mortality was 84.9%. During hypotension, CO was lower with major blood loss (1.9), than without major loss (5.0; P = 0.0008). Low PetCO₂ was associated with low CO (P < 0.0001). Low PetCO₂ was associated (P ≤ 0.0012) with ISS > 20, hypotension, bradycardia, major blood loss, abnormal pupils, cardiac arrest, and death. Low CO was associated (P ≤ 0.0059) with ISS > 20, hypotension, bradycardia, major blood loss, abnormal pupils, cardiac arrest, and death.

Conclusions

During emergency department resuscitation, a decline in PetCO₂ correlates with decreases in noninvasive CO in emergently intubated trauma patients. Decreasing PetCO₂ and declining NICOM CO are associated with hemodynamic instability, hemorrhage, abnormal pupils, and death. The study indicates that NICOM CO values are clinically discriminate and have physiologic validity.