Cardiac output monitoring: less invasiveness, less accuracy?

Leveraging Hypotension Prediction Index to Forecast LPS-Induced Acute Lung Injury and Inflammation in a Porcine Model: Exploring the Role of Hypoxia-Inducible Factor in Circulatory Shock

Acute respiratory distress syndrome (ARDS) is a critical illness in critically unwell patients, characterized by refractory hypoxemia and shock. This study evaluates an early detection tool and investigates the relationship between hypoxia and circulatory shock in ARDS, to improve diagnostic precision and therapy customization. We used a porcine model, inducing ARDS with mechanical ventilation and intratracheal plus intravenous lipopolysaccharide (LPS) injection. Hemodynamic changes were monitored using an Acumen IQ sensor and a ForeSight Elite sensor connected to the HemoSphere platform. We evaluated tissue damage, inflammatory response, and hypoxia-inducible factor (HIF) alterations using enzyme-linked immunosorbent assay and immunohistochemistry. The results showed severe hypotension and increased heart rates post-LPS exposure, with a notable rise in the hypotension prediction index (HPI) during acute lung injury (p = 0.024). Tissue oxygen saturation dropped considerably in the right brain region. Interestingly, post-injury HIF-2α levels were lower at the end of the experiment. Our findings imply that the HPI can effectively predict ARDS-related hypotension. HIF expression levels may serve as possible markers of rapid ARDS progression. Further research should be conducted on the clinical value of this novel approach in critical care, as well as the relationship between the HIF pathway and ARDS-associated hypotension.

[Intraoperative Hemodynamic Monitoring and Management]

Postoperative deaths are a consequence of postoperative complications - including acute kidney injury and myocardial injury. Postoperative complications are associated with non-modifiable patient-specific risk factors (i.e., age, medical history), but also with potentially modifiable risk factors - including intraoperative hypotension and compromised intraoperative blood flow. Based on patient- and surgery-specific risk factors, the intraoperative hemodynamic monitoring strategy needs to be selected. Intraoperative hypotension is associated with postoperative organ failure and should thus be avoided. To optimize intraoperative hemodynamics, cardiac output-guided hemodynamic management has been proposed. Cardiac output-guided hemodynamic management aims at optimizing oxygen delivery using fluids, vasopressors, and inotropes. Cardiac output-guided hemodynamic management has been shown to reduce postoperative complications compared to routine hemodynamic management in high-risk patients having major surgery.

Improved haemodynamic stability and cerebral tissue oxygenation after induction of anaesthesia with sufentanil compared to remifentanil: a randomised controlled trial

BACKGROUND

Balanced anaesthesia with propofol and remifentanil, compared to sufentanil, often decreases mean arterial pressure (MAP), heart rate (HR) and cardiac index (CI), raising concerns on tissue-oxygenation. This distinct haemodynamic suppression might be attenuated by atropine. This double blinded RCT, investigates if induction with propofol-sufentanil results in higher CI and tissue-oxygenation than with propofol-remifentanil and if atropine has more pronounced beneficial effects on CI and tissue-oxygenation in a remifentanil-based anaesthesia.

METHODS

In seventy patients scheduled for coronary bypass grafting (CABG), anaesthesia was induced and maintained with propofol target controlled infusion (TCI) with a target effect-site concentration (Cet) of 2.0 μg ml- 1 and either sufentanil (TCI Cet 0.48 ng ml- 1) or remifentanil (TCI Cet 8 ng ml- 1). If HR dropped below 60 bpm, methylatropine (1 mg) was administered intravenously. Relative changes (∆) in MAP, HR, stroke volume (SV), CI and cerebral (SctO2) and peripheral (SptO2) tissue-oxygenation during induction of anaesthesia and after atropine administration were analysed.

RESULTS

The sufentanil group compared to the remifentanil group showed significantly less decrease in MAP (∆ = - 23 ± 13 vs. -36 ± 13 mmHg), HR (∆ = - 5 ± 7 vs. -10 ± 10 bpm), SV (∆ = - 23 ± 18 vs. -35 ± 19 ml) and CI (∆ = - 0.8 (- 1.5 to - 0.5) vs. -1.5 (- 2.0 to - 1.1) l min- 1 m- 2), while SctO2 (∆ = 9 ± 5 vs. 6 ± 4%) showed more increase with no difference in ∆SptO2 (∆ = 8 ± 7 vs. 8 ± 8%). Atropine caused higher ∆HR (13 (9 to 19) vs. 10 ± 6 bpm) and ∆CI (0.4 ± 0.4 vs. 0.2 ± 0.3 l min- 1 m- 2) in sufentanil vs. remifentanil-based anaesthesia, with no difference in ∆MAP, ∆SV and ∆SctO2 and ∆SptO2.

CONCLUSION

Induction of anaesthesia with propofol and sufentanil results in improved haemodynamic stability and higher SctO2 compared to propofol and remifentanil in patients having CABG. Administration of atropine might be useful to counteract or prevent the haemodynamic suppression associated with these opioids.

TRIAL REGISTRATION

Clinicaltrials.gov on June 7, 2013 (trial ID: NCT01871935 ).

Disagreement in cardiac output measurements between fourth-generation FloTrac and critical care ultrasonography in patients with circulatory shock: a prospective observational study

Background

Cardiac output measurements may inform diagnosis and provide guidance of therapeutic interventions in patients with hemodynamic instability. The FloTrac™ algorithm uses uncalibrated arterial pressure waveform analysis to estimate cardiac output. Recently, a new version of the algorithm has been developed. The aim was to assess the agreement between FloTrac™ and routinely performed cardiac output measurements obtained by critical care ultrasonography in patients with circulatory shock.

Methods

A prospective observational study was performed in a tertiary hospital from June 2016 to January 2017. Adult critically ill patients with circulatory shock were eligible for inclusion. Cardiac output was measured simultaneously using FloTrac™ with a fourth-generation algorithm (CO_AP) and critical care ultrasonography (CO_CCUS). The strength of linear correlation of both methods was determined by the Pearson coefficient. Bland-Altman plot and four-quadrant plot were used to track agreement and trending ability.

Result

Eighty-nine paired cardiac output measurements were performed in 17 patients during their first 24 h of admittance. CO_AP and CO_CCUS had strong positive linear correlation (r² = 0.60, p < 0.001). Bias of CO_AP and CO_CCUS was 0.2 L min⁻¹ (95% CI − 0.2 to 0.6) with limits of agreement of − 3.6 L min⁻¹ (95% CI − 4.3 to − 2.9) to 4.0 L min⁻¹ (95% CI 3.3 to 4.7). The percentage error was 65.6% (95% CI 53.2 to 77.3). Concordance rate was 64.4%.

Conclusions

In critically ill patients with circulatory shock, there was disagreement and clinically unacceptable trending ability between values of cardiac output obtained by uncalibrated arterial pressure waveform analysis and critical care ultrasonography.

Trial registration

Clinicaltrials.gov, NCT02912624, registered on September 23, 2016

Electronic supplementary material

The online version of this article (10.1186/s40560-019-0373-5) contains supplementary material, which is available to authorized users.

Minimally invasive cardiac output technologies in the ICU: putting it all together

PURPOSE OF REVIEW

Haemodynamic monitoring is a cornerstone in the diagnosis and evaluation of treatment in critically ill patients in circulatory distress. The interest in using minimally invasive cardiac output monitors is growing. The purpose of this review is to discuss the currently available devices to provide an overview of their validation studies in order to answer the question whether these devices are ready for implementation in clinical practice.

RECENT FINDINGS

Current evidence shows that minimally invasive cardiac output monitoring devices are not yet interchangeable with (trans)pulmonary thermodilution in measuring cardiac output. However, validation studies are generally single centre, are based on small sample sizes in heterogeneous groups, and differ in the statistical methods used.

SUMMARY

Minimally and noninvasive monitoring devices may not be sufficiently accurate to replace (trans)pulmonary thermodilution in estimating cardiac output. The current paradigm shift to explore trending ability rather than investigating agreement of absolute values alone is to be applauded. Future research should focus on the effectiveness of these devices in the context of (functional) haemodynamic monitoring before adoption into clinical practice can be recommended.

Journal of Clinical Monitoring and Computing 2016 end of year summary: cardiovascular and hemodynamic monitoring

The assessment and optimization of cardiovascular and hemodynamic variables is a mainstay of patient management in the care for critically ill patients in the intensive care unit (ICU) or the operating room (OR). It is, therefore, of outstanding importance to meticulously validate technologies for hemodynamic monitoring and to study their applicability in clinical practice and, finally, their impact on treatment decisions and on patient outcome. In this regard, the Journal of Clinical Monitoring and Computing (JCMC) is an ideal platform for publishing research in the field of cardiovascular and hemodynamic monitoring. In this review, we highlight papers published last year in the JCMC in order to summarize and discuss recent developments in this research area.