Capillary refill time as part of an early warning score for rapid response team activation is an independent predictor of outcomes

DiCARTTM device to measure capillary refill time: a validation study in patients with acute circulatory failure

Capillary Refill Time (CRT) is a valuable metric to assess cutaneous perfusion. Its prognostic value in patients with acute circulatory failure has been reported as improved when the measurement is standardized. The DiCART™ device is a fully automated CRT measurement tool requiring validation. We conducted a comparative interventional single-center study including 25 patients with acute circulatory failure, to evaluate the agreement between CRT measured by an automated measurement device (CRTDiCART) and CRT measured clinically (CRTCLIN). CRT was measured on the fingertip, chest, and knee. Three measurements were performed at each location to obtain an average for each site. The measurements were conducted both clinically and using the DiCART™ device by two different operators, each blinded to the results. Agreement was determined using intraclass correlation coefficient (ICC) and Bland and Altman analysis. The ICC between CRTCLIN and CRTDiCART was 0.46 (95% Confidence Interval (CI) 0.32, 0.59) across all measurement sites; the mean bias was 0.23s (95% CI -0.17, 0.64), with upper Limit of Agreement (LoA) 2.77s (95% CI 2.44, 3.20) and lower LoA - 2.30s (-2.73, -1.97). Intra observer ICC was 0.85 (95% CI 0.74, 0.91) for CRTCLIN and 0.43 (95% CI 0.15, 0.64) for CRTDICART. Inter observer ICC was 0.86 (95% CI 0.76, 0.92) for CRTCLIN and was 0.41 (95% CI 0.14, 0,63) for CRTDICART. The DiCART™ device showed poor agreement with clinical CRT in patients with acute circulatory failure, which does not support its use in routine practice.

A pilot observational study of the association of 24-hour mortality with the subjective assessment of the forearm skin temperature and moisture compared to other bedside indicators of illness severity

Background

Although the association of peripheral skin temperature with infection, serious illness and death have been recognised for centuries, few studies have explicitly compared this finding with other bedside indicators of illness severity. This study compared subjectively assessed dorsal forearm skin temperature and moisture with other indicators of illness severity.

Methods

Non-interventional observational study of acutely ill medical patients admitted to a low-resource Ugandan hospital, which examined the association of subjectively assessed dorsal forearm skin temperature and other bedside findings with death within 24 h.

Results

While in hospital 653 patients had 2,104 observations; the dorsal forearm skin was subjectively felt to be abnormally hot or cold at 239 observations, and this finding was associated with 24-hour mortality (odds ratio 4.48, 95% CI 1.89-10.46); this increased risk of death was comparable to the increased mortality risk associated with tachypnoea, hypoxia, and a Shock Index >1.0, but considerably lower than that associated with a Kitovu Fast Triage score >0. When stratified according to both temperature and wetness, 'cold and wet' and 'hot and wet' skin were associated with higher early warning scores. Cold or hot forearm skin had a specificity for 24-hour mortality of 0.83, but a sensitivity of only 0.34; therefore, its absence does not rule-out the chance of imminent death.

Conclusion

Touching and feeling the skin temperature and moisture is a valuable clinical sign, which can be rapidly determined at the bedside. However, although it has high specificity, its sensitivity for imminent death is low.

Research Progress on the Measurement Methods and Clinical Significance of Capillary Refill Time

The monitoring of peripheral circulation, as indicated by the capillary refill time, is a sensitive and accurate method of assessing the microcirculatory status of the body. It is a widely used tool for the evaluation of critically ill patients, the guidance of therapeutic interventions, and the assessment of prognosis. In recent years, there has been a growing emphasis on microcirculation monitoring which has led to an increased focus on capillary refill time. The International Sepsis Guidelines, the American Academy of Pediatrics, the World Health Organization, and the American Heart Association all recommend its inclusion in the evaluation of the system in question. Furthermore, the methodology for its measurement has evolved from a traditional manual approach to semiautomatic and fully automatic techniques. This article presents a comprehensive overview of the current research on the measurement of capillary refill time, with a particular focus on its clinical significance. The aim is to provide a valuable reference for clinicians and researchers and further advance the development and application of microcirculation monitoring technology.

Perspectives for capillary refill time in clinical practice for sepsis

BACKGROUND

Capillary refill time (CRT) is defined as the time taken for color to return to an external capillary bed after pressure is applied to cause blanching. Recent studies demonstrated the benefits of CRT in guiding fluid therapy for sepsis. However, lack of consistency among physicians in how to perform and interpret CRT has led to a low interobserver agreement for this assessment tool, which prevents its availability in sepsis clinical settings.

OBJECTIVE

To give physicians a concise overview of CRT and explore recent evidence on its reliability and value in the management of sepsis.

RESEARCH DESIGN

A narrative review.

RESULTS

This narrative review summarizes the factors affecting CRT values, for example, age, sex, temperature, light, observation techniques, work experience, training level and differences in CRT measurement methods. The methods of reducing the variability of CRT are synthesized. Based on studies with highly reproducible CRT measurements and an excellent inter-rater concordance, we recommend the standardized CRT assessment method. The threshold of normal CRT values is discussed. The application of CRT in different phases of sepsis management is summarized.

CONCLUSIONS

Recent data confirm the value of CRT in critically ill patients. CRT should be detected by trained physicians using standardized methods and reducing the effect of ambient-related factors. Its association with severe infection, microcirculation, tissue perfusion response, organ dysfunction and adverse outcomes makes this approach a very attractive tool in sepsis. Further studies should confirm its value in the management of sepsis.

IMPLICATIONS FOR CLINICAL PRACTICE

As a simple assessment, CRT deserves more attention even though it has not been widely applied at the bedside. CRT could provide nursing staff with patient's microcirculatory status, which may help to develop individualized nursing plans and improve the patient's care quality and treatment outcomes.

Early peripheral perfusion monitoring in septic shock

Septic shock is a frequent critical clinical condition and a leading cause of death in critically ill individuals. However, it is challenging to identify affected patients early. In this article, we discuss new perspectives on the methods and uses of peripheral perfusion monitoring, considering the concept of a dysregulated response. Physical examination, and visual and ultrasonographic techniques are used to measure peripheral microcirculatory blood flow to reflect tissue perfusion. Compared with other monitoring techniques, peripheral perfusion monitoring has the benefits of low invasiveness and good repeatability, and allows for quick therapeutic judgments, which have significant practical relevance. Peripheral perfusion monitoring is an effective tool to detect early signs of septic shock, autonomic dysfunction, and organ damage. This method can also be used to evaluate treatment effectiveness, direct fluid resuscitation and the use of vasoactive medications, and monitor vascular reactivity, microcirculatory disorders, and endothelial cell damage. Recent introductions of novel peripheral perfusion monitoring methods, new knowledge of peripheral perfusion kinetics, and multimodal peripheral perfusion evaluation methods have occurred. To investigate new knowledge and therapeutic implications, we examined the methodological attributes and mechanisms of peripheral perfusion monitoring, in this study.

Consensus for the Development of a New Early Warning Score for Predicting Patients' Clinical Deterioration in Angola: A Delphi Study

Background: Nearly 30 years since its inception, the early warning scores (EWSs) remain pivotal, yet variations have emerged for hospital and prehospital use. Aggregated scores, reflecting multiple physiological parameters, outperform single-parameter systems in assessing acute illness severity, though consensus on optimal approaches is lacking. Resource-limited countries, including Angola, lack adapted EWSs, emphasizing the need for cost-effective and adaptable solutions to enhance patient care. Objective: To explore the perspectives of Angolan experts to identify physiological parameters suitable for incorporation into existing EWSs, allowing the development of a new tool adjusted to the healthcare context in Angola. Methods: We conducted a three-round Delphi survey, engaging a national expert panel comprising twenty-five physicians and nurses with expertise in internal medicine, surgery, emergency rooms, intensive care units, and/or teachers at universities or at teaching courses in these fields. Participants were asked to rate items using a five-point Likert scale. Consensus was achieved if the items received a rating ≥ 80% from the panel. Results: Consensus was evident for the inclusion of standard physiological parameters, such as systolic blood pressure, heart rate, respiratory rate, temperature, oxygen saturation, neurological status, and the presence or absence of supplemental oxygen. Furthermore, there was consensus for the consideration of specific items, namely, seizures, jaundice, cyanosis, capillary refill time, and pain-typically not included in the current EWSs. Consensus was reached regarding the exclusion of both oxygen saturation and temperature measurements in healthcare settings where oximeters and thermometers might not be readily available. Conclusion: Angolan experts were able to identify the physiological parameters suitable for incorporation into the basic EWSs. Further study must be conducted to test and validate the impact of the newly suggested vital parameters on the discriminant and predictive capability of a new aggregated model specifically adjusted to the Angolan healthcare setting.

Pilot study on optimizing pressure for standardized capillary refill time measurement

Purpose

Capillary Refill Time (CRT) measurement has gained increasing attention in the field of sepsis and septic shock. Recognizing pressure as a fundamental determinant in CRT measurement is crucial for establishing a standardized CRT measurement procedure. In this preliminary study, we elucidated the optimal pressing strength for CRT measurement by analyzing the CRTs measured under varying pressures.

Method

Seventeen healthy individuals were enlisted to undergo CRT tests on their fingertips at various pressure levels. The applied force was initiated at 0.5N and incrementally increased by 0.5N until it reached 10.5N. An integrated Photoplethysmography (PPG) device was employed to capture fluctuations in light intensity. The CRT was automatically derived from the PPG signals via a specialized algorithm. The study included correlation assessment and reliability evaluation. Box plot and Bland-Altman plot were used to visualize the impact of pressure levels on CRTs.

Results

A dataset of 1414 CRTs across 21 pressures showed significant differences (Kruskal-Wallis test, p < 0.0001), highlighting the impact of pressure on CRT. CRT values between 4.5N and 10.5N pressures varied less, with an Intraclass Correlation Coefficient (ICC) of 0.499 indicating moderate consistency. Notably, CRTs at 10N and 10.5N pressures revealed a high ICC of 0.790, suggesting strong agreement.

Conclusion

A pressure range of 4.5N-10.5N is recommended for stable CRT measurements, with 10.0N-10.5N providing optimal consistency and reliability.

Society of Critical Care Medicine Guidelines on Recognizing and Responding to Clinical Deterioration Outside the ICU: 2023

RATIONALE

Clinical deterioration of patients hospitalized outside the ICU is a source of potentially reversible morbidity and mortality. To address this, some acute care hospitals have implemented systems aimed at detecting and responding to such patients.

OBJECTIVES

To provide evidence-based recommendations for hospital clinicians and administrators to optimize recognition and response to clinical deterioration in non-ICU patients.

PANEL DESIGN

The 25-member panel included representatives from medicine, nursing, respiratory therapy, pharmacy, patient/family partners, and clinician-methodologists with expertise in developing evidence-based Clinical Practice Guidelines.

METHODS

We generated actionable questions using the Population, Intervention, Control, and Outcomes (PICO) format and performed a systematic review of the literature to identify and synthesize the best available evidence. We used the Grading of Recommendations Assessment, Development, and Evaluation Approach to determine certainty in the evidence and to formulate recommendations and good practice statements (GPSs).

RESULTS

The panel issued 10 statements on recognizing and responding to non-ICU patients with critical illness. Healthcare personnel and institutions should ensure that all vital sign acquisition is timely and accurate (GPS). We make no recommendation on the use of continuous vital sign monitoring among unselected patients. We suggest focused education for bedside clinicians in signs of clinical deterioration, and we also suggest that patient/family/care partners' concerns be included in decisions to obtain additional opinions and help (both conditional recommendations). We recommend hospital-wide deployment of a rapid response team or medical emergency team (RRT/MET) with explicit activation criteria (strong recommendation). We make no recommendation about RRT/MET professional composition or inclusion of palliative care members on the responding team but suggest that the skill set of responders should include eliciting patients' goals of care (conditional recommendation). Finally, quality improvement processes should be part of a rapid response system.

CONCLUSIONS

The panel provided guidance to inform clinicians and administrators on effective processes to improve the care of patients at-risk for developing critical illness outside the ICU.

Prognostic value of capillary refill time in adult patients: a systematic review with meta-analysis

PURPOSE

Acute circulatory failure leads to tissue hypoperfusion. Capillary refill time (CRT) has been widely studied, but its predictive value remains debated. We conducted a meta-analysis to assess the ability of CRT to predict death or adverse events in a context at risk or confirmed acute circulatory failure in adults.

METHOD

MEDLINE, EMBASE, and Google scholar databases were screened for relevant studies. The pooled area under the ROC curve (AUC ROC), sensitivity, specificity, threshold, and diagnostic odds ratio using a random-effects model were determined. The primary analysis was the ability of abnormal CRT to predict death in patients with acute circulatory failure. Secondary analysis included the ability of CRT to predict death or adverse events in patients at risk or with confirmed acute circulatory failure, the comparison with lactate, and the identification of explanatory factors associated with better accuracy.

RESULTS

A total of 60,656 patients in 23 studies were included. Concerning the primary analysis, the pooled AUC ROC of 13 studies was 0.66 (95%CI [0.59; 0.76]), and pooled sensitivity was 54% (95%CI [43; 64]). The pooled specificity was 72% (95%CI [55; 84]). The pooled diagnostic odds ratio was 3.4 (95%CI [1.4; 8.3]). Concerning the secondary analysis, the pooled AUC ROC of 23 studies was 0.69 (95%CI [0.65; 0.74]). The prognostic value of CRT compared to lactate was not significantly different. High-quality CRT was associated with a greater accuracy.

CONCLUSION

CRT poorly predicted death and adverse events in patients at risk or established acute circulatory failure. Its accuracy is greater when high-quality CRT measurement is performed.

Clinical evaluation of peripheral tissue perfusion as a predictor of mortality in sepsis and septic shock in the intensive care unit: Systematic review and meta-analysis

OBJECTIVE

To determine the diagnostic performance of the clinical evaluation of peripheral tissue perfusion in the prediction of mortality.

DESIGN

Systematic review and meta-analysis.

SETTING

Intensive care unit.

PATIENTS AND PARTICIPANTS

Patients with sepsis and septic shock.

INTERVENTIONS

Studies of patients with sepsis and/or septic shock that associated clinical monitoring of tissue perfusion with mortality were included. A systematic review was performed by searching the PubMed/MEDLINE, Cochrane Library, SCOPUS, and OVID databases.

MAIN VARIABLES OF INTEREST

The risk of bias was assessed with the QUADAS-2 tool. Sensitivity and specificity were calculated to evaluate the predictive accuracy for mortality. Review Manager software version 5.4 was used to draw the forest plot graphs, and Stata version 15.1 was used to build the hierarchical summary receiver operating characteristic model.

RESULTS

Thirteen studies were included, with a total of 1667 patients and 17 analyses. Two articles evaluated the temperature gradient, four evaluated the capillary refill time, and seven evaluated the mottling in the skin. In most studies, the outcome was mortality at 14 or 28 days. The pooled sensitivity of the included studies was 70%, specificity 75.9% (95% CI, 61.6%-86.2%), diagnostic odds ratio 7.41 (95% CI, 3.91-14.04), and positive and negative likelihood ratios 2.91 (95% CI, 1.80-4.72) and 0.39 (95% CI, 0.30-0.51), respectively.

CONCLUSIONS

Clinical evaluation of tissue perfusion at the bedside is a useful tool, with moderate sensitivity and specificity, to identify patients with a higher risk of death among those with sepsis and septic shock.

REGISTRATION

PROSPERO CRD42019134351.

Association of Sublingual Microcirculation Parameters and Capillary Refill Time in the Early Phase of ICU Admission

OBJECTIVES

This observational study was conducted to investigate capillary refill time (CRT) during the early phase of ICU admission in relationship with microvascular flow alteration and outcome in critically ill patients.

DESIGN

Prospective, observational, pilot study.

SETTING

ICU in a university hospital.

PATIENTS

Two hundred eighty-two critically ill adult patients admitted to the ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All patients underwent simultaneous measurements by CRT and sidestream dark field imaging within 24 hours of ICU admission. Other clinical data such as demographic characteristics, hemodynamics, laboratory values, treatment, and physiologic parameters were also included simultaneously. Microcirculatory measurements were performed at 10.2 ± 5.7 hours after ICU admission. Of the 282 included patients, 106 (37.6%) were female, the median (interquartile range) age was 63 years (53-74 yr), and the median Sequential Organ Failure Assessment (SOFA) score was 5 (2-7). The primary finding was the association between CRT and simultaneous the condition of peripheral circulation (microvascular flow index [MFI]: r = -0.4430, p < 0.001; proportion of perfused vessels: r = -0.3708, p < 0.001; heterogeneity index: r = 0.4378, p < 0.001; perfused vessel density: r = -0.1835, p = 0.0020; except total vessel density: p = 0.9641; and De Backer score: p = 0.5202) in critically ill patients. In addition, this relationship was also maintained in subgroups. Microcirculatory flow abnormalities, 28-day mortality, and SOFA score appeared to be more severe for increasing CRT. In a multivariable analysis, prolonged CRT was independently associated with microvascular flow abnormalities (MFI < 2.6; odds ratio [OR], 1.608; 95% CI, 2.1-10.2; p < 0.001). Similarly, multivariable analysis identified CRT as an independent predictor of 28-day mortality (OR, 1.296; 95% CI, 1.078-1.558; p = 0.006).

CONCLUSIONS

In our ICU population, a single-spot prolonged CRT was independently associated with abnormal microcirculation and increased mortality.

Rapid Response Team Activation Triggers in Adults and Children: An Integrative Review

PURPOSE

This integrative review aims to identify the triggers for rapid response team (RRT) activation and their outcomes in pediatric patients and to compare them with those of adult patients. In addition, this integrative review synthesizes the outcomes of cardiopulmonary resuscitation (CPR), intensive care unit (ICU) admission, length of hospital stay, and mortality following RRT activation.

METHOD

An integrative review using the Whittemore and Knafl methodology was undertaken with a search of three large databases (PubMed, Ovid MEDLINE, and CINAHL) and found 25 relevant studies published in the years 2017 through 2022.

RESULTS

Tachypnea, decreased oxygen saturation, tachycardia, changes in blood pressure, and level of consciousness were the most common triggers in both populations. However, specific activation triggers differed between children and adults.

CONCLUSIONS

The most common triggers for RRT are detectable through vital signs monitoring; therefore, vigilant tracking of patients' vital signs is critical and can provide early clues to clinical deterioration.

[Hemodynamic Monitoring 2.0 - What is Possible on Normal Wards?]

Life threatening events after surgery often occur on the ward. These events could be prevented by early detection of clinical deterioration of patients' health status during ward care. Therefore, an adequate monitoring could help to identify patients at risk, since there is an imbalance of monitoring intensity and the occurrence of life-threatening events during hospital stay.Additional monitoring on the general ward could lead to more patient safety. The practicability of additional monitoring needs to be considered, and therefore the use of available monitoring systems on the ward is limited. Capillary refill time (CRT) and the passive leg raise test (PLR) seem to be usable intermittent monitoring techniques.Continuous monitoring systems ensure a better detection of unwanted events and hemodynamic trends. However, the increased workload for the nursing staff and tethered monitors are unfavorable. Future trends of developing wireless monitoring systems are of paramount importance in this respect. Controlling artefacts is crucial for the successful balance between false alarms and "missed events". An adequate reaction is needed when detecting adverse events to avoid a "failure to rescue".

Capillary refill time in sepsis: A useful and easily accessible tool for evaluating perfusion in children

The international sepsis guidelines emphasize the importance of early identification along with the combined administration of fluids, antibiotics and vasopressors as essential steps in the treatment of septic shock in childhood. However, despite these recommendations, septic shock mortality continues to be very high, especially in countries with limited resources. Cardiovascular involvement is common and, in most cases, determines the outcomes. Early recognition of hemodynamic dysfunction, both in the macro and microcirculation, can help improve outcomes. Capillary refill time (CRT) is a useful, available and easily accessible tool at all levels of care. It is a clinical sign of capillary vasoconstriction due to an excessive sympathetic response which seeks to improve blood redistribution from the micro- to the macrocirculation. An important reason for functionally evaluating the microcirculation is that, in septic shock, the correction of macrocirculation variables is assumed to result in improved tissue perfusion. This has been termed "hemodynamic coherence." However, this coherence often does not occur in advanced stages of the disease. Capillary refill time is useful in guiding fluid resuscitation and identifying more seriously affected sepsis patients. Several factors can affect its measurement, which should preferably be standardized and performed on the upper extremities. In this review, we seek to clarify a few common questions regarding CRT and guide its correct use in patients with sepsis.

Review of 20 Years of Continuous Quality Improvement of a Rapid Response System, at Four Institutions, to Identify Key Process Responsible for Its Success

BACKGROUND:

Rapid response systems are still in development, and their practices vary significantly from hospital to hospital. Although the literature supports their value and a four-arm structure, it is unclear within these arms (efferent, afferent, quality assurance, administrative arms) which processes and procedures are responsible for their efficacy. This article reports the evolution of a rapid response system over many years at four institutions and considers the key elements that likely contribute to its efficacy.

METHODS:

Retrospective evaluation of the processes, procedures, and outcomes of an adult general-ward rapid response system as it evolved, at four nonaffiliated community medical centers, spanning 2 decades of development and refinement. System and patient outcomes examined included the number of rapid response system activations/1,000 admissions, time to rapid response system activation and/or interventions, cardiac arrest rate, and/or hospital mortality over time.

RESULTS:

In the three hospitals that collected control and intervention data, there was significant increase in earlier and total number of rapid response system activations, more rapid administration of protocolized interventions, and associated decreases in cardiac arrest rate and hospital mortality of the respective population. In all four institutions three important common rapid response system processes were identified: early identification of at-risk patient using a novel focused bedside-assessment tool, leading to classification of the pathophysiologic process, linked to goal-directed intervention protocols.

CONCLUSIONS:

Our review of a rapid response system that evolved over 20 years across four unrelated institutions revealed a common care pathway that coupled a focused bedside at-risk patient assessment leading to pathophysiologic classification of the patients decline linked to goal-directed intervention protocols. We speculate that the improved outcomes observed are a consequence of effective implementation and coupling of these three processes, as they are important in identifying and treating early the signs of tissue hypoxia and hypoperfusion, which remain the basic pathophysiologic threats of acute deterioration.

Point-Of-Care Capillary Refill Technology Improves Accuracy of Peripheral Perfusion Assessment

Background: Peripheral perfusion assessment is used routinely at the bedside by measuring the capillary refill time (CRT). Recent clinical trials have shown evidence to its ability to recognize conditions with decreased end organ perfusion as well as guiding therapeutic interventions in sepsis. However, the current standard of physician assessment at the bedside has shown large variability. New technology can improve the precision and repeatability of CRT affecting translation of previous high impact research.

Methods: This was a prospective, observational study in the intensive care unit and emergency department at a quaternary care hospital using a non-invasive finger sensor for CRT. The device CRT was compared to the gold standard of trained research personnel assessment of CRT as well as to providers clinically caring for the patient.

Results: Pearson correlations coefficients were performed across 89 pairs of measurements. The Pearson correlation for the device CRT compared to research personnel CRT was 0.693. The Pearson correlation for the provider CRT compared to research personnel CRT was 0.359.

Conclusions: New point-of-care technology shows great promise in the ability to improve peripheral perfusion assessment performed at the bedside in the emergency department triage and during active resuscitation. This standardized approach allows for better translation of prior research that is limited by the subjectivity of manual visual assessment of CRT.

Clinical use of peripheral perfusion parameters in septic shock

PURPOSE OF REVIEW

Current goals of resuscitation in septic shock are mainly a fixed volume of fluids and vasopressors to correct hypotension and improve tissue perfusion indicated by decreasing lactate levels.

RECENT FINDINGS

Abnormal peripheral perfusion by objective and subjective parameters are associated with increased mortality in various phases of the treatment of critically ill patients including patients with septic shock. Ongoing resuscitation in septic shock patients with normal peripheral perfusion is not associated with improved outcome, rather with increased mortality. Mitigation of fluid resuscitation by using parameters of peripheral perfusion in septic shock seems to be safe.

SUMMARY

Septic shock patients with normal peripheral perfusion represent a different clinical phenotype of patients that might benefit from limited resuscitation efforts. Parameters of peripheral perfusion could be used to guide the individualization of patients with septic shock.