Shock Management for Cardio-surgical ICU Patients - The Golden Hours

Development and usability testing of a patient digital twin for critical care education: a mixed methods study

Background

Digital twins are computerized patient replicas that allow clinical interventions testing in silico to minimize preventable patient harm. Our group has developed a novel application software utilizing a digital twin patient model based on electronic health record (EHR) variables to simulate clinical trajectories during the initial 6 h of critical illness. This study aimed to assess the usability, workload, and acceptance of the digital twin application as an educational tool in critical care.

Methods

A mixed methods study was conducted during seven user testing sessions of the digital twin application with thirty-five first-year internal medicine residents. Qualitative data were collected using a think-aloud and semi-structured interview format, while quantitative measurements included the System Usability Scale (SUS), NASA Task Load Index (NASA-TLX), and a short survey.

Results

Median SUS scores and NASA-TLX were 70 (IQR 62.5-82.5) and 29.2 (IQR 22.5-34.2), consistent with good software usability and low to moderate workload, respectively. Residents expressed interest in using the digital twin application for ICU rotations and identified five themes for software improvement: clinical fidelity, interface organization, learning experience, serious gaming, and implementation strategies.

Conclusion

A digital twin application based on EHR clinical variables showed good usability and high acceptance for critical care education.

Trends and Outcomes of Transcatheter Tricuspid Valve Repair and Surgical Tricuspid Valve Repair in Patients With Tricuspid Valve Regurgitation; A Population Based Study

Data on clinical outcomes of transcatheter tricuspid valve repair (TTVR) compared with surgical tricuspid valve repair (STVR) in patients with tricuspid valve regurgitation (TVR) remains limited. Data from the national inpatient sample (2016-2020) and propensity-score matched (PSM) analysis was utilized to determine adjusted odds ratio (aOR) of inpatient mortality and major clinical outcomes of TTVR compated with STVR in patients with TVR. A total of 37,115 patients with TVR were included: 1830 (4.9%) and 35,285 (95.1%) underwent TTVR and STVR, respectively. After PSM, there was no statistically significant difference in baseline characteristics and medical comorbidities between both groups. Compared with STVR, TTVR was associated with lower inpatient mortality (aOR 0.43 [0.31-0.59], P < 0.01), cardiovascular complications (aOR 0.47 [0.3-0.45], P < 0.01), hemodynamic complications (aOR 0.47 [0.4-0.55], P < 0.01), infectious complications (aOR 0.44 [0.34-0.57], P < 0.01), renal complications (aOR 0.56 [0.45-0.64], P < 0.01), and need for blood transfusion. There was no statistically significant difference in odds of major bleeding events (aOR 0.92 [0.64-1.45], P 0.84). Also, TTVR was associated with less mean length of stay (7 days vs 15 days, P < 0.01) and less cost of hospitalization ($59,921 vs $89,618) compared with STVR. There was an increase in the utility of TTVR associated with a decrease in the utility of STVR from 2016 to 2020 (P < 0.01). Our study showed that compared with STVR, TTVR was associated with lower inpatient mortality and clinical events. Nevertheless, further studies are needed to investigate the difference in outcomes between both procedures.

Wingless-related integration site (WNT) signaling is activated during the inflammatory response upon cardiac surgery: A translational study

Objective

Cardiac surgery and the use of cardiopulmonary bypass initiate a systemic inflammatory response. Wingless-related integration site (WNT) signaling is part of the innate immunity and has been attributed a major role in the regulation of inflammation. In preclinical research, WNT-5a may sustain an inflammatory response and cause endothelial dysfunction. Our aim was to investigate WNT signaling after cardiac surgery and its association with postoperative inflammation (Clinicaltrials.gov, NCT04058496).

Methods

In this prospective, single-center, observational study, 64 consecutive patients for coronary artery bypass grafting (CABG) ± valve surgery were assigned into three groups: off-pump CABG (n = 28), on-pump CABG (n = 16) and combined valve-CABG surgery (n = 20). Blood samples were acquired before surgery, at intensive care unit (ICU) admission and 4, 8, and 48 h thereafter. Plasma concentrations of WNT-5a and its antagonists Secreted frizzled-related protein 1 (sFRP-1), Secreted frizzled-related protein 5 (sFRP-5), and WNT inhibitory factor 1 (WIF-1) were determined by enzyme-linked immunosorbent assay. In addition, plasma concentrations of six inflammatory cytokines were measured by multiplex immunoassay. Parameters were analyzed for evolution of plasma concentration over time, interactions, intergroup differences, and association with clinical outcome parameters.

Results

At baseline, WNT-5a, sFRP-1, and WIF-1 were present in a minimal concentration, while sFRP-5 was elevated. A higher baseline value of WNT-5a, sFRP-5, and WIF-1 resulted in higher subsequent values of the respective parameter. At ICU admission, WNT-5a and sFRP-5 reached their maximum and minimum value, respectively. WIF-1 decreased over time and was lowest 8 h after surgery. sFRP-1 changed minimally over time. While WNT-5a returned to the baseline within 48 h, sFRP-5 and WIF-1 did not reach their baseline value at 48 h. Of the investigated WNT system components, only WIF-1 partially reflected the severity of surgery. WNT-5a and WIF-1 had an impact on postoperative fluid balance and noradrenaline requirement.

Conclusion

WNT-5a, sFRP-5, and WIF-1 are part of the systemic inflammatory response after cardiac surgery. WNT-5a peaks immediately after cardiac surgery and returns to baseline within 48 h, presumably modulated by its antagonist sFRP-5. Based on this translational study, WNT-5a antagonism may be further investigated to assess potentially beneficial effects in patients with a dysregulated inflammation after cardiac surgery.

Cardiovascular Safety of Clonidine and Dexmedetomidine in Critically Ill Patients after Cardiac Surgery

Purpose

The aim of this retrospective study was to assess the haemodynamic adverse effects of clonidine and dexmedetomidine in critically ill patients after cardiac surgery.

Methods

2769 patients were screened during the 30-month study period. Heart rate (HR), mean arterial pressure (MAP), and norepinephrine requirements were assessed 3-hourly during the first 12 hours of the continuous drug infusion. Results are given as median (interquartile range) or numbers (percentages).

Results

Patients receiving clonidine (n = 193) were younger (66 (57-73) vs 70 (63-77) years, p=0.003) and had a lower SAPS II (35 (27-48) vs 41 (31-54), p=0.008) compared with patients receiving dexmedetomidine (n = 141). At the start of the drug infusion, HR (90 (75-100) vs 90 (80-105) bpm, p=0.028), MAP (70 (65-80) vs 70 (65-75) mmHg, p=0.093), and norepinephrine (0.05 (0.00-0.11) vs 0.12 (0.03-0.19) mcg/kg/min, p < 0.001) were recorded in patients with clonidine and dexmedetomidine. Bradycardia (HR < 60 bpm) developed in 7.8% with clonidine and 5.7% with dexmedetomidine (p=0.51). Between baseline and 12 hours, norepinephrine remained stable in the clonidine group (0.00 (-0.04-0.02) mcg/kg/min) and decreased in the dexmedetomidine group (-0.03 (-0.10-0.02) mcg/kg/min, p=0.007).

Conclusions

Dexmedetomidine and the low-cost drug clonidine can both be used safely in selected patients after cardiac surgery.

QTc prolongation after haloperidol administration in critically ill patients post cardiovascular surgery: A cohort study and review of the literature

Objective

From case reports, haloperidol administration has been associated with QTc prolongation, torsades de pointes, and sudden cardiac death. In a vulnerable population of critically ill patients after cardiac surgery, however, it is unclear whether haloperidol administration affects the QTc interval. Thus, the aim of this study is to explore the effect of haloperidol in low doses on this interval.

Method

This retrospective cohort study was performed on a cardio-surgical intensive care unit (ICU), screened 2,216 patients and eventually included 68 patients with delirium managed with oral and intravenous haloperidol. In this retrospective analysis, electrocardiograms were taken prior and within 24 h after haloperidol administration. The effect of haloperidol on QTc was determined with a Person correlation, and inter-group differences were measured with new long QT comparisons.

Results

In total, 68 patients were included, the median age was 71 (64–79) years and predominantly male (77%). Haloperidol administration followed ICU admission by three days and the cumulative dose was 4 (2–9) mg. As a result, haloperidol administration did not affect the QTc (r = 0.144, p = 0.23). In total, 31% (21/68 patients) had a long QT before and 27.9% (19/68 patients) after haloperidol administration. Only 12% (8/68 patients) developed a newly onset long QT. These patients were not different in the route of administration, cumulative haloperidol doses, comorbidities, laboratory findings, or medications.

Significance of results

These results indicated that low-dose intravenous haloperidol was safe and not clinically relevant for the development of a newly onset long QT syndrome or adverse outcomes and support recent findings inside and outside the ICU setting.

The modern cardiovascular care unit: the cardiologist managing multiorgan dysfunction

PURPOSE OF REVIEW

Despite many advances in the management of critically ill patients, cardiogenic shock remains a challenge because it is associated with high mortality. Even if there is no universally accepted definition of cardiogenic shock, end-perfusion organ dysfunction is an obligatory and major criterion of its definition.Organ dysfunction is an indicator that cardiogenic shock is already at an advanced stage and is undergoing a rapid self-aggravating evolution. The aim of the review is to highlight the importance to diagnose and to manage the organ dysfunction occurring in the cardiogenic shock patients by providing the best literature published this year.

RECENT FINDINGS

The first step is to diagnose the organ dysfunction and to assess their severity. Echo has an important and increasing place regarding the assessment of end-organ impairment whereas no new biomarker popped up.

SUMMARY

In this review, we aimed to highlight for intensivists and cardiologists managing cardiogenic shock, the recent advances in the care of end-organ dysfunctions associated with cardiogenic shock. The management of organ dysfunction is based on the improvement of the cardiac function by etiologic therapy, inotropes and assist devices but will often necessitate organ supports in hospitals with the right level of equipment and multidisciplinary expertise.

Intra-operative events during cardiac surgery are risk factors for the development of delirium in the ICU

BACKGROUND

Risk factors for delirium following cardiac surgery are incompletely understood. The aim of this study was to investigate whether intra-operative pathophysiological alterations and therapeutic interventions influence the risk of post-operative delirium.

METHODS

This retrospective cohort study was performed in a 12-bed cardiosurgical intensive care unit (ICU) of a university hospital and included patients consecutively admitted after cardiac surgery during a 2-month period. The diagnosis of delirium was made clinically using validated scores. Comparisons between patients with and without delirium were performed with non-parametric tests. Logistic regression was applied to identify independent risk factors. Results are given as number (percent) or median (range).

RESULTS

Of the 194 consecutive post-cardiac surgery patients, 50 (26 %) developed delirium during their ICU stay. Univariate analysis revealed that significant differences between patients with and without delirium occurred in the following intra-operative variables: duration of cardiopulmonary bypass (184 [72-299] vs 113 (37-717) minutes, p < 0.001), lowest mean arterial pressure (50 [30-70] vs 55 [30-75] mmHg, p = 0.004), lowest haemoglobin level (85 [56-133] vs 98 [53-150] g/L, p = 0.005), lowest body temperature (34.5 [24.4-37.2] vs 35.1 [23.9-37.2] °C, p = 0.035), highest noradrenaline support (0.11 [0.00-0.69] vs 0.07 [0.00-0.42] μg/kg/minute, p = 0.001), and frequency of red blood cell transfusions (18 [36 %] vs 26 [18 %], p = 0.018) and platelet transfusions (23 [46 %] vs 24 [17 %], p < 0.001). Only platelet transfusions remained an independent risk factor in the multivariate analysis (p < 0.001).

CONCLUSIONS

In patients undergoing cardiac surgery, various intra-operative events, such as transfusion of platelets, were risk factors for the development of a post-operative delirium in the ICU. Further research is needed to unravel the underlying mechanisms.

Shock Management for Cardio-surgical Intensive Care Unit Patient: The Silver Days

Shock in cardio-surgical intensive care unit (ICU) patients requires prompt identification of the underlying condition and timely therapeutic interventions. Management during the first 6 hours, also referred to as "the golden hours", is of paramount importance to reverse the shock state and improve the patient's outcome. The authors have previously described a state-of-the-art diagnostic work-up and discussed how to optimise preload, vascular tone, contractility, heart rate and oxygen delivery during this phase. Ideally, shock can be reversed during this initial period. However, some patients might have developed multiple organ dysfunction, which persists beyond the first 6 hours despite the early haemodynamic treatment goals having been accomplished. This period, also referred to as "the silver days", is the focus of this review. The authors discuss how to reduce vasopressor load and how to minimise adrenergic stress by using alternative inotropes, extracorporeal life-support and short acting beta-blockers. The review incorporates data on fluid weaning, safe ventilation, daily interruption of sedation, delirium management and early rehabilitation. It includes practical recommendations in areas where the evidence is scarce or controversial. Although the focus is on cardio-surgery ICU patients, most of the considerations apply to critical ill patients in general.