Capillary refill time in the hands and feet of normal newborn infants

Skin-color-independent robust assessment of capillary refill time

Capillary Refill Time (CRT) assesses peripheral perfusion in resource-limited settings. However, the repeatability and reproducibility of CRT measurements are limited for individuals with darker skin. This paper presents quantitative CRT measurements demonstrating good performance and repeatability across all Fitzpatrick skin phototypes. The study involved 22 volunteers and utilized controlled compression at 7 kPa, an RGB video camera, and cocircular polarized white LED light. CRT was determined by calculating the time constant of an exponential regression applied to the mean pixel intensity of the green (G) channel. An adaptive algorithm identifies the optimal regression region for noise reduction, and flags inappropriate readings. The results indicate that 80% of the CRT readings fell within a 20% range of the expected CRT value. The repetition standard deviation was 17%. These findings suggest the potential for developing reliable and reproducible quantitative CRT methods for robust measurements in patient triage, monitoring, and telehealth applications.

Hemodynamic dysfunction in neonatal sepsis

Cardiovascular disturbances are a frequent occurrence in neonatal sepsis. Preterm and term infants are particularly vulnerable due to the unique features of their cardiovascular function and reserve, compared to older children and adults. The clinical manifestations of neonatal sepsis are a product of the variable inflammatory pathways involved (warm vs. cold shock physiology), developmental state of the cardiovascular system, and hormonal responses. Targeted neonatal echocardiography has played an important role in advancing our knowledge, may help delineate specific hemodynamic phenotypes in real-time, and supports an individualized physiology-based management of sepsis-associated cardiovascular dysfunction. IMPACT: Cardiovascular dysfunction is a common sequela of sepsis. This review aims to highlight the pathophysiological mechanisms involved in hemodynamic disturbance in neonatal sepsis, provide insights from targeted neonatal echocardiography-based clinical studies, and suggest its potential incorporation in day-to-day management.

Standardized capillary refill time and relation to clinical parameters in hospitalized dogs

OBJECTIVE

To assess the relationship between various physical and clinicopathologic parameters and the capillary refill time (CRT) using a standard method; to evaluate the influence of emergency room (ER) versus ICU hospital location on CRT; and to identify latent subgroups among the CRT distribution.

DESIGN

Prospective, observational study.

SETTING

University teaching hospital.

ANIMALS

Client-owned dogs in the ER (n = 40) and ICU (n = 71).

INTERVENTIONS

The CRT was defined as the duration required for the oral mucosa of the upper lip to return to its original color after blanching for 4 seconds. The CRT was recorded in seconds to the 10ths place by a single observer using an automated recording device.

MEASUREMENTS AND MAIN RESULTS

Median CRT for all dogs was 1.1 seconds (ER, 1.2 s; ICU, 1.1 s; P = 1.000). The CRT was significantly associated with rectal temperature (P = 0.004), systolic blood pressure (P = 0.028), body weight (P = 0.031), mucous membrane color (P = 0.007), skin turgor (P = 0.039), and acute patient physiologic and laboratory evaluation mentation score (P = 0.019) for all dogs. The CRT was related to a greater number of variables in the ER than in the ICU patient population. In general, the total population of dogs had CRTs belonging to 1 of 2 groups: either ≤1.2 or ≥1.7 seconds. A statistically significant association was found between body weight CRT ≥1.3 seconds (P = 0.02).

CONCLUSIONS

A CRT following blanching for 4 seconds may provide insight into the hydration status and hemodynamic stability of canine patients. Further research into its clinical application is warranted.

Advances in the Approaches Using Peripheral Perfusion for Monitoring Hemodynamic Status

Measures of peripheral perfusion can be used to assess the hemodynamic status of critically ill patients. By monitoring peripheral perfusion status, clinicians can promptly initiate life-saving therapy and reduce the likelihood of shock-associated death. Historically, abnormal perfusion has been indicated by the observation of pale, cold, and clammy skin with increased capillary refill time. The utility of these assessments has been debated given that clinicians may vary in their clinical interpretation of body temperature and refill time. Considering these constraints, current sepsis bundles suggest the need to revise resuscitation guidelines. New technologies have been developed to calculate capillary refill time in the hopes of identifying a new gold standard for clinical care. These devices measure either light reflected at the surface of the fingertip (reflected light), or light transmitted through the inside of the fingertip (transmitted light). These new technologies may enable clinicians to monitor peripheral perfusion status more accurately and may increase the potential for ubiquitous hemodynamic monitoring across different clinical settings. This review will summarize the different methods available for peripheral perfusion monitoring and will discuss the advantages and disadvantages of each approach.

Optical Fibre Sensor for Simultaneous Measurement of Capillary Refill Time and Contact Pressure

The widely applied capillary refill time (CRT) measurement is currently performed by manually applying pressure and using a stopwatch to record the time taken for the skin to recover its normal colour after a blanching pressure is applied. This method is highly subjective and observer-dependent. This paper presents a new, integrated optical sensor probe, combining monitoring of the capillary refilling process with the blanching pressure applied. The sensor consists of an optical fibre-based reflectance photoplethysmography (PPG) sensor to measure the reflected light signal, as well as a fibre Bragg grating (FBG) to measure the applied blanching pressure and to indicate the time when pressure is released. This sensor was applied to calculate the CRT (1.38 ± 0.66 s) of 10 healthy adult volunteers with (55.2 ± 21.8 kPa) blanching pressures. The form of the capillary refilling data was investigated by fitting using an exponential regression model (R² > 0.96). The integrated probe has the potential to improve the reliability of CRT measurements by standardising the optimum duration and magnitude of the pressure.

A cool response-The influence of ambient temperature on capillary refill time

OBJECTIVE

To describe the effect of low ambient temperature on skin temperature and capillary refill (CR) time in forehead, sternum and finger pulp.

METHODS

An observational, nonrandomized experimental study on 15 healthy subjects (6 females) in a cold room (8°C). Outcome measures were skin temperature and quantified CR test after application of a standardized blanching pressure (9 N/cm² ) using digital photographic polarization spectroscopy to generate CR times.

RESULTS

The finger pulp showed marked temperature fall and prolonged CR times (>10 seconds). The CR registrations of the forehead and sternum were more comparable to curves observed in a control material at room temperature, and skin temperature falls were less marked. CR times were not prolonged in forehead measurements. At the sternum, some individuals showed CR times beyond guideline recommendations despite only a marginal reduction in skin temperature.

CONCLUSIONS

Low ambient temperature is a strong independent factor for CR time at peripheral sites. Reservation about sternum as a site of measurement is warranted since cold provocation produced prolonged CR times in some individuals. We found that the forehead is the most thermostable of the 3 sites and thus the preferred site to avoid ambient temperature artifact in measuring CR time.

Reflectance spectroscopy: to shed new light on the capillary refill test

To use Bioengineering methodology is used to achieve, at five anatomical sites, a detailed, quantitative assessment of the return of blood content to the blanched area, during the Capillary Refill (CR) test. An observational, non-randomized, experimental study on 23 healthy subjects (14 females) was performed in our climate controlled skin physiology laboratory. Our main outcome measures were based on the chronological assessment and quantification of red blood cell concentration (RBC) after the release of blanching pressure in the CR test, using Tissue Viability Imaging (TiVi), a digital photographic technique based on polarisation spectroscopy. TiVi enabled collection of detailed data on skin RBC concentration during the CR test. The results were shown as curves with skin blood concentration (TiVi-value) on the y-axis and the time on the x-axis. Quantitative CR responses showed site and temperature variability. We also suggest possible objective endpoint values from the capillary refill curve. Detailed data on skin RBC concentration during the CR test is easily obtained and allows objective determination of end points not possible to achieve by naked eye assessment. These findings have the potential to place the utility of the CR test in a clinical setting in a new light. Picture: Regular photograph and TiVi Image showing CR test and corresponding graph for the CR response.

Culture-Negative Early-Onset Neonatal Sepsis - At the Crossroad Between Efficient Sepsis Care and Antimicrobial Stewardship

Sepsis is a leading cause of mortality and morbidity in neonates. Presenting clinical symptoms are unspecific. Sensitivity and positive predictive value of biomarkers at onset of symptoms are suboptimal. Clinical suspicion therefore frequently leads to empirical antibiotic therapy in uninfected infants. The incidence of culture confirmed early-onset sepsis is rather low, around 0.4-0.8/1000 term infants in high-income countries. Six to 16 times more infants receive therapy for culture-negative sepsis in the absence of a positive blood culture. Thus, culture-negative sepsis contributes to high antibiotic consumption in neonatal units. Antibiotics may be life-saving for the few infants who are truly infected. However, overuse of broad-spectrum antibiotics increases colonization with antibiotic resistant bacteria. Antibiotic therapy also induces perturbations of the non-resilient early life microbiota with potentially long lasting negative impact on the individual's own health. Currently there is no uniform consensus definition for neonatal sepsis. This leads to variations in management. Two factors may reduce the number of culture-negative sepsis cases. First, obtaining adequate blood cultures (0.5-1 mL) at symptom onset is mandatory. Unless there is a strong clinical or biochemical indication to prolong antibiotics physician need to trust the culture results and to stop antibiotics for suspected sepsis within 36-48 h. Secondly, an international robust and pragmatic neonatal sepsis definition is urgently needed. Neonatal sepsis is a dynamic condition. Rigorous evaluation of clinical symptoms ("organ dysfunction") over 36-48 h in combination with appropriately selected biomarkers ("dysregulated host response") may be used to support or refute a sepsis diagnosis.

Capillary Refill Time in Adults Has Poor Inter-Observer Agreement

Objectives

Capillary refill time (CRT) has been taught as a rapid indicator of circulatory status but to be a useful clinical test, CRT needs to be reproducible when performed by another health care worker. No inter-rater agreement studies have been reported for adult patients. The aim of this study was to determine the inter-observer reliability of CRT in a sample of adult emergency department (ED) patients. Methods This prospective observational study included clinically stable ED patients with a variety of conditions from two community EDs. A doctor and a nurse each measured CRT by estimation to the nearest half-second using a standard method on each patient. They were blinded to each other's measurements. The primary outcome of interest was inter-rater agreement. Secondary outcome was agreement in classification as normal or abnormal according to accepted definitions. Data was analysed using bias plot analysis, correlation, absolute percent agreement and kappa analysis. Results Totally, 209 patients were enrolled; 51% were female and 86% were Caucasian. Median CRT was 2 seconds (95% CI 2–2.35 seconds). The mean difference between measurements by the different observers was 0 second, however the 95% limits of agreement were very wide (–1.7 to +1.9 seconds). Agreement was 70% for classification of ‘normal’ or ‘abnormal’ using the 2-second definition of normal, with a kappa of 0.38. Conclusion Interobserver agreement in measurement of CRT was poor in adult subjects with wide limits of agreement. This is a serious threat to the appropriateness of this test for use in clinical practice.

Diffuse Reflectance Spectroscopy: Getting the Capillary Refill Test Under One's Thumb

The capillary refill test was introduced in 1947 to help estimate circulatory status in critically ill patients. Guidelines commonly state that refill should occur within 2 s after releasing 5 s of firm pressure (e.g., by the physician's finger) in the normal healthy supine patient. A slower refill time indicates poor skin perfusion, which can be caused by conditions including sepsis, blood loss, hypoperfusion, and hypothermia. Since its introduction, the clinical usefulness of the test has been debated. Advocates point out its feasibility and simplicity and claim that it can indicate changes in vascular status earlier than changes in vital signs such as heart rate. Critics, on the other hand, stress that the lack of standardization in how the test is performed and the highly subjective nature of the naked eye assessment, as well as the test's susceptibility to ambient factors, markedly lowers the clinical value. The aim of the present work is to describe in detail the course of the refill event and to suggest potentially more objective and exact endpoint values for the capillary refill test using diffuse polarization spectroscopy.

Inotropes for preterm babies during the transition period after birth: friend or foe?

During the transition to extrauterine life, preterm infants are at high risk of developing circulatory failure. Currently, hypotension is used as major diagnostic criteria for starting treatments such as fluid boluses, inotropes or steroids. Most of these treatment options have not been studied in large randomised controlled trials for efficacy and safety and are under discussions. A wide variety in their use is reported in the literature and clear evidence about which inotrope or other treatment should be preferred is lacking. In addition, there is ongoing debate about the appropriate threshold values for blood pressure. Other diagnostic measures for poor circulation are functional echocardiography, near-infrared spectroscopy, capillary refill time, base excess and serum lactate. Large randomised controlled trials for the use of dopamine and dobutamine in preterm infants <32 weeks gestation are under way to fill the knowledge gaps on the assessment of circulatory compromise and on efficacy and safety of the studied age-appropriate drug formulations.

Perfusion monitoring and intraventricular hemorrhage in preterm infants

Cardiovascular instability in preterm infants during the early postnatal period correlates with the development of intraventricular hemorrhage (IVH). Due to the correlation between hypotension and fluctuation of blood pressure, treatment was targeted specifically at hypotension to prevent IVH, but this was not successful. Recently, several novel perfusion markers have been found to be correlated with the development of IVH, and they are of current interest in cardiovascular management. In this review, the correlation between IVH and conventional, as well as novel, perfusion markers is examined.

Paediatric capillary refill times

Capillary refill time (CRT) has become universally used in paediatrics; it however has a number of limitations to its use as a marker of peripheral perfusion. These limitations include the effects of ambient temperature, environmental lighting conditions as well as different values being recorded at different sites of assessment; these have all been shown to have a bearing on its value. In older patients its range varies from 2 seconds to 4 seconds. All these variations have led to the removal of CRT from the trauma score. This paper reviews the influences on paediatric CRT. CRT does have a role as one of the physiological assessments of peripheral perfusion in combination with other markers such as heart rate, respiratory rate and level of consciousness.

Lack of agreement between different observers and methods in the measurement of capillary refill time in healthy volunteers: an observational study

OBJECTIVE

Peripheral perfusion abnormalities are relevant manifestations of shock. Capillary refill time is commonly used for their evaluation. However, the reproducibility of capillary refill time measurements and their correlation with other variables of peripheral perfusion, have not been comprehensively evaluated. Our goal was to determine, in healthy volunteers, the agreement between different methods of capillary refill time quantification and different observers, as well as their correlation with other markers of peripheral perfusion. Methods: We studied 63 healthy volunteers. Two observers measured capillary refill time by means of two methods, direct view (CRTchronome ter) and video analysis (CRTvideo). We also measured perfusion index (PI) derived from pulse plethysmography and finger pad temperature (T°peripheral). The agreement between observers and methods was assessed using the Bland and Altman method. Correlations were calculated using Pearson's correlation. A p-value<0.05 was considered significant.

RESULTS

The 95% limits of agreement between the two observers were 1.9 sec for CRTchronometer and 1.7 sec for CRTvideo. The 95% limits of agreement between CRTchronometer and CRTvideo were 1.7 sec for observer 1 and 2.3 sec for observer 2. Measurements of CRTchronometer performed by the two observers were correlated with T°peripheral. Measurements of CRTvideo performed by the two observers were correlated with T°peripheral and perfusion index.

CONCLUSION

In healthy volunteers, measurements of capillary refill time performed by either different observers or different methods showed poor agreement. Nevertheless, capillary refill time still reflected peripheral perfusion as shown by its correlation with objective variables of peripheral perfusion.

Validity and reliability of measurement of capillary refill time in children: a systematic review

BACKGROUND

Most guidelines recommend the use of capillary refill time (CRT) as part of the routine assessment of unwell children, but there is little consensus on the optimum method of measurement and cut-off time.

METHODS

We searched Medline (from 1948), Embase (from 1980) and CINAHL (from 1991) to June 2014 to identify studies with information on the normal range of CRT in healthy children, the validity of CRT compared with reference standard measures of haemodynamic status, reliability and factors influencing measurement of CRT, such as body site, pressing time and temperature.

FINDINGS

We included 21 studies on 1915 children. Four studies provided information on the relationship between CRT and measures of cardiovascular status, 13 provided data on the normal range of CRT, 7 provided data on reliability and 10 assessed the effect of various confounding factors. In children over 7 days of age, the upper limit of normal CRT is approximately 2 s when measured on a finger, and 4 s when measured on the chest or foot, irrespective of whether the child is feverish or not. Longer pressing times and ambient temperature outside 20°C-25°C are associated with longer CRT. Evidence suggests that the use of stopwatches reduces variability between observers.

INTERPRETATION

We recommend use of the following standardised CRT method of measurement: press on the finger for 5 s using moderate pressure at an ambient temperature of 20°C-25°C. A capillary refill time of 3 s or more should be considered abnormal.

Management of hypotension in preterm infants (The HIP Trial): a randomised controlled trial of hypotension management in extremely low gestational age newborns

BACKGROUND

Extremely preterm babies (delivered at <28 completed weeks of gestation) are frequently diagnosed with hypotension and treated with inotropic and pressor drugs in the immediate postnatal period. Dopamine is the most commonly used first-line drug. Babies who are treated for hypotension more frequently sustain brain injury, have long-term disability or die compared to those who are not. Despite the widespread use of drugs to treat hypotension in such infants, evidence for efficacy is lacking, and the effect of these agents on long-term outcomes is unknown.

HYPOTHESIS

In extremely preterm babies, restricting the use of dopamine when mean blood pressure (BP) values fall below a nominal threshold and using clinical criteria to determine escalation of support ('restricted' approach) will result in improved neonatal and longer-term developmental outcomes. RESEARCH PLAN: In an international multi-centre randomised trial, 830 infants born at <28 weeks of gestation, and within 72 h of birth, will be allocated to 1 of 2 alternative treatment options (dopamine vs. restricted approach) to determine the better strategy for the management of BP, using a conventional threshold to commence treatment. The first co-primary outcome of survival without brain injury will be determined at 36 weeks' postmenstrual age and the second co-primary outcome (survival without neurodevelopmental disability) will be assessed at 2 years of age, corrected for prematurity.

DISCUSSION

It is essential that appropriately designed trials be performed to define the most appropriate management strategies for managing low BP in extremely preterm babies.

Capillary refill time and cardiac output in children undergoing cardiac catheterization

OBJECTIVE

Many pediatric healthcare providers believe that capillary refill time is a measure of perfusion and cardiac output in children. Despite its widespread use, there are no studies examining the relationship of capillary refill time to cardiac output in noncritically ill children. This study examined the inter-rater reliability of capillary refill time and its relationship to hemoglobin and with cardiac output in pediatric patients undergoing cardiac catheterization.

DESIGN

Prospective observational study.

SETTING

Tertiary care pediatric hospital.

PATIENTS

A total of 58 children, ages 0.3-17 yrs, with congenital heart disease undergoing cardiac catheterization.

INTERVENTIONS

Two clinicians performed two measurements of capillary refill time in a standardized fashion on 58 children undergoing cardiac catheterization. Cardiac output was determined by the Fick method within 15 mins of the first assessment of capillary refill time (time 1).

MEASUREMENTS AND MAIN RESULTS

Capillary refill time and cardiac output measurements were obtained in 44 children, and 108 paired measurements of capillary refill time were obtained to assess inter-rater reliability. The mean capillary refill time was 1.2 secs (±0.5 secs), and the mean cardiac output was 3.6 L/min/m (2.2-5.7 L/min/m). The inter-rater intraclass correlation coefficient was 0.12 (time 1) (95% confidence interval -0.15 to +0.37) and was 0.32 (95% confidence interval 0.058-0.54) at the end of the catheterization (time 2). A significant association was noted between average capillary refill time at time 1 and hemoglobin, with higher hemoglobin correlating with longer capillary refill time (p = .015). There was no significant correlation between the average capillary refill time taken at the time of cardiac output measurement (time 1) and measured cardiac output (r = .331, 95% confidence interval for r, .066-.552).

CONCLUSIONS

We found that the inter-rater reliability of capillary refill time was poor and variable under controlled conditions and capillary refill time was not correlated with cardiac output in anesthetized nonacutely ill pediatric patients undergoing cardiac catheterization. Caution should be used in inferring cardiac output from capillary refill time measurements alone.

Peripheral haemodynamics in newborns: best practice guidelines

Peripheral haemodynamics refers to blood flow, which determines oxygen and nutrient delivery to the tissues. Peripheral blood flow is affected by vascular resistance and blood pressure, which in turn varies with cardiac function. Arterial oxygen content depends on the blood haemoglobin concentration (Hb) and arterial pO2; tissue oxygen delivery depends on the position of the oxygen-dissociation curve, which is determined by temperature and the amount of adult or fetal haemoglobin. Methods available to study tissue perfusion include near-infrared spectroscopy, Doppler flowmetry, orthogonal polarisation spectral imaging and the peripheral perfusion index. Cardiac function, blood gases, Hb, and peripheral temperature all affect blood flow and oxygen extraction. Blood pressure appears to be less important. Other factors likely to play a role are the administration of vasoactive medications and ventilation strategies, which affect blood gases and cardiac output by changing the intrathoracic pressure.

The influence of skin temperature and skin perfusion on the cephalocaudal progression of jaundice in newborns

AIM

Despite being widely recognized, the cephalocaudal progression of jaundice in newborns (Kramer's Rule) has never been satisfactorily explained. The aim of this study was to test the hypothesis that the cephalocaudal progression of jaundice in newborns is related to regional differences in skin temperature and skin perfusion.

METHODS

A convenience sample of 50 infants was included in the study. On each infant, a transcutaneous bilirubin, skin temperature and capillary refill time measurement was made at five sites; the forehead, sternum, lower abdomen, mid thigh and sole. The relationship between the three variables was studied by analysis of variance.

RESULTS

The transcutaneous bilirubin measurements upheld Kramer's observation, being significantly higher at the head and chest than at the thigh and sole (P < 0.001). A similar pattern was found for both skin temperature and capillary refill, both significantly different at the head compared to the sole (P < 0.001).

CONCLUSION

The results of the study support the hypothesis that the cephalocaudal progression of jaundice in newborns is a consequence of diminished capillary blood flow in distal parts of the body. It is hypothesized that newborn infants preferentially perfuse their head and proximal parts of their body in the first few days of life, leading to higher temperatures and increased bilirubin deposition at these sites.

Bedside detection of low systemic flow in the very low birth weight infant on day 1 of life

We aimed to assess the relationship between the clinical and biochemical parameters of perfusion and superior vena cava (SVC) flow in a prospective observational cohort study of very low birth weight (VLBW) infants. Newborns with congenital heart disease were excluded. Echocardiographic evaluation of SVC flow was performed in the first 24 h of life. Capillary refill time (forehead, sternum and toe), mean blood pressure, urine output and serum lactate concentration were also measured simultaneously. Thirty-eight VLBW infants were examined. Eight patients (21%) had SVC flow less than 40 ml/kg/min. There was a poor correlation between the capillary refill time (in all sites), mean blood pressure, urine output and SVC flow. The correlation coefficient for the serum lactate concentration was r = -0.28, p = 0.15. The median serum lactate concentration was 3.5 (range 2.8-8.5) vs. 2.7 (range 1.2-6.9) mmol/l (p = 0.01) in low flow versus normal flow states. A serum lactate concentration of >2.8 was 100% sensitive and 60% specific for detecting a low flow state. Combining a capillary refill time of >4 s with a serum lactate concentration of >4 mmol/l had a specificity of 97% for detecting a low SVC flow state. Serum lactate concentrations are higher in low SVC flow states. A capillary refill time of >4 s combined with serum lactate concentrations >4 mmol/l increased the specificity and positive and negative predictive values of detecting a low SVC flow state.

Evaluation and treatment of hypotension in the preterm infant

A large proportion of very preterm infants receive treatment for hypotension. The definition of hypotension is unclear, and, currently, there is no evidence that treating it improves outcomes or, indeed, which treatment to choose among the available alternatives. Assessment of circulatory adequacy of the preterm infant requires a careful clinical assessment and may also require ancillary investigations. The most commonly used interventions, fluid boluses and dopamine, are problematic: fluid boluses are statistically associated with worse clinical outcomes and may not even increase blood pressure, whereas dopamine increases blood pressure mostly by causing vasoconstriction and may decrease perfusion. For neither intervention is there any reliable data showing clinical benefit. Prospective trials of intervention for hypotension and circulatory compromise are urgently required.

A multidisciplinary survey on capillary refill time: Inconsistent performance and interpretation of a common clinical test

OBJECTIVE

Capillary refill time is a common clinical test used in pediatric critical care and emergency medicine. Despite this, we hypothesize that capillary refill time is performed inconsistently and its interpretation by healthcare providers in the acute care setting is variable.

DESIGN

Multidisciplinary survey.

SETTING

Canadian tertiary care pediatric hospital.

SUBJECTS

Subjects were 198 pediatric healthcare providers.

INTERVENTIONS

A self-administered questionnaire survey was sent to healthcare providers in pediatric and neonatal critical care, emergency medicine, and cardiology.

MEASUREMENTS AND MAIN RESULTS

Seventy-eight surveys were returned: 23 of 33 pediatric trainees (70%), 22 of 38 staff physicians (58%), and 33 of 125 nurses (26%). Ninety-five percent of pediatric healthcare providers reported performing capillary refill time on most patients. However, while 90% of nurses and 70% of trainees described performing capillary refill time on every patient, only 18% of staff physicians reported performing capillary refill time routinely on every patient. Although all participants responded that a capillary refill time of >3 secs was abnormal, responders were divided on the definition of normal capillary refill time. While other sites were described, responders most commonly reported performing capillary refill time on a patient's chest. Ninety-six percent of responders agreed that prolonged capillary refill time indicates abnormal perfusion.

CONCLUSIONS

The results of this single-institution survey show that while most nurses and pediatric trainees reported using capillary refill time on every patient as a test for perfusion, only a few staff physicians reported using capillary refill time on every patient. In addition, although this study shows that the majority of survey responders stated that they used capillary refill time frequently, we observed no consistent response in how they performed and interpreted capillary refill time. Given that the use of this simple, noninvasive clinical test is supported by many pediatric organizations and pediatricians, the results of this study emphasize the need to examine why this test is inconsistently performed by healthcare providers so as to ensure its reliable performance in the future.

Capillary refill time is an unreliable indicator of cardiovascular status in term neonates

PURPOSE

Decisions regarding the need for volume replacement in neonates often are made in the immediate newborn period. Capillary refill time (CRT) is used as an indicator of circulatory status; however, recent data show that CRT varies considerably with age, ambient and skin temperature, anatomical site of measurement, and duration of pressure. The purpose of this study was to (1) examine the relationship between CRT and heart rate (HR) and blood pressure (BP) in term neonates, and (2) evaluate the differences among CRT values measured at 3 body sites and with varying duration of cutaneous pressure.

DESIGN

This was a prospective, cross-sectional, correlational study. Subjects Forty-two appropriate-weight-for-gestational-age (AGA) neonates with birthweights, (M = 3407; SD = +/- 540 g), gestational ages (M = 39 weeks; SD = +/- 1 week), and sex (21 males, 21 females). Infants had no history of perinatal distress or maternal chorioamnionitis.

METHODS

Each neonate was studied prospectively 1 to 4 hours after birth. The infants were clothed with only a diaper and evaluated on a radiant warmer bed set to achieve an axillary temperature of 36.5 degrees to 37.0 degrees C. Capillary refill time was measured with a digital stopwatch at 3 sites: volar surface of finger (F), plantar surface of heel (H), and lower sternum (St), using brief (1- to 2-second) and extended (3- to 4-second) pressure. Heart rate was auscultated and counted for 60 seconds, and BP was measured by oscillometry. Relationships among variables were assessed by Pearson correlation coefficient, analysis of variance, and multiple regression analysis. The Bonferroni correction for multiple comparisons was applied.

MAIN OUTCOME MEASURES

Capillary refill time, blood pressure, and heart rate.

PRINCIPAL RESULTS

There was no significant site variation for CRT for either brief (2.4 +/- 0.6 to 2.9 +/- 1.0 seconds) or extended (3.8 +/- 0.8 to 4.3 +/- 0.8 seconds) pressure. However, regardless of site, CRT was greater when extended versus brief pressure was used (P < 0.001). There were no significant correlations between HR and CRT. There was a moderate, direct relationship between BP and CRT observed in the following anatomic sites: (1) sternum/extended pressure and systolic BP (SBP), diastolic BP, and mean BP (r = 0.35, P = 0.02; r = 0.49, P = 0.001; and r = 0.43, P = 0.005, respectively); (2) sternum/brief pressure and SBP (r = 0.31, P = 0.05); and (3) finger/extended pressure and SBP (r = 0.30, P = 0.05).

CONCLUSIONS

An unanticipated moderate, direct correlation between BP and CRT was observed; prolongation of CRT occurred with elevated blood pressure. This finding may have been secondary to increased circulating vasoactive substances in the newborn period; measurement of these substances was beyond the scope of this study. In addition, CRT was highly dependent on the duration of cutaneous pressure, regardless of the site. These 2 findings indicate that CRT may be an unreliable indicator of cardiovascular status in the term neonate during the first 4 hours after birth.

Is measurement of capillary refill time useful as part of the initial assessment of children?

OBJECTIVE

The purpose of this study was to establish the usefulness of capillary refill time when measured during the initial assessment of children.

METHODS

All children with spontaneous illness attending a paediatric accident and emergency department over a 7-month period were eligible for entry into the study. Capillary refill time was measured at the fingertip, using a standard technique, as part of the initial assessment. Each child was then followed up to ascertain clinical progress, including the need for admission, intravenous fluids, length of stay and diagnosis, as well as the white cell count when this was available. The value of capillary refill time as a predictor of the markers of illness severity was then assessed.

RESULTS

Capillary refill time measurements were recorded on 4878 children. There was no significant association of capillary refill time with meningococcal disease, other significant bacterial illness or the white cell count. A prolonged capillary refill time was associated with a more urgent triage category, the administration of a fluid bolus and the length of hospital stay (P<0.0001). The best performance was obtained when a capillary refill time of 3s or more is taken to be 'prolonged'. However, this gave positive predictive values of only 9% for a triage category of 1 or 2 (negative predictive value 97%), 11% for requiring a fluid bolus (negative predictive value 99%), 55% for hospital admission (negative predictive value 65%) and 22% for stay over 2 days/death (negative predictive value 91%).

CONCLUSION

The prolongation of capillary refill time is a poor predictor of the need for intravenous fluid bolus or hospital admission.

Clinical detection of low upper body blood flow in very premature infants using blood pressure, capillary refill time, and central-peripheral temperature difference

OBJECTIVE

To determine the accuracy of blood pressure (BP), capillary refill time (CRT), and central-peripheral temperature difference (CPTd) for detecting low upper body blood flow in the first day after birth.

METHODS

A prospective, two centre cohort study of 128 infants born at < 30 weeks gestation. Invasive BP (n = 108), CRT (n = 128), and CPTd (n = 46) were performed immediately before echocardiographic measurement of superior vena cava (SVC) flow at three, 5-10, and 24 hours after birth.

RESULTS

Forty four (34%) infants had low SVC flow (< 41 ml/kg/min) in the first day, 13/122 (11%) at three hours, 39/126 (31%) at 5-10 hours, and 4/119 (3%) at 24 hours. CPTd did not detect infants with low flows. Combining all observations in the first 24 hours, CRT > or = 3 seconds had 55% sensitivity and 81% specificity, mean BP < 30 mm Hg had 59% sensitivity and 77% specificity, and systolic BP < 40 mm Hg had 76% sensitivity and 68% specificity for detecting low SVC flow. Combining a mean BP < 30 mm Hg and/or central CRT > or = 3 seconds increases the sensitivity to 78%.

CONCLUSIONS

Low upper body blood flow is common in the first day after birth and strongly associated with peri/intraventricular haemorrhage. BP and CRT are imperfect bedside tests for detecting low blood flow in the first day after birth.

Hypotension in the very low birthweight infant: the old, the new, and the uncertain

Hypotension occurs in up to 20% of very low birthweight infants, usually in the first 48 hours after birth. Its importance lies in its possible causal link with brain injury. Its management is controversial.

Reactive hyperemia and interleukin 6, interleukin 8, and tumor necrosis factor-alpha in the diagnosis of early-onset neonatal sepsis

OBJECTIVE

To evaluate the diagnostic value of peripheral circulatory reactive hyperemia and serum levels of interleukin-6 (IL-6), IL-8, and tumor necrosis factor-alpha (TNF-alpha) in early-onset neonatal sepsis.

METHODS

Reactive hyperemia in the dorsal hand and serum levels of IL-6, IL-8, and TNF-alpha were studied in newborn infants (n = 32; gestational age 39 +/- 3 weeks) who had been admitted to the neonatal unit because of suspected sepsis <48 hours after birth. On admission, reactive hyperemia after a standardized arterial occlusion was measured with laser Doppler technique, and blood samples were taken for cytokine analyses. On the basis of predetermined criteria, the infants subsequently were classified as septic (n = 12) or not (n = 20).

RESULTS

The degree of reactive hyperemia was higher in the group with sepsis (median + 170% perfusion increase) than in that without (+37%). On admission, serum levels of IL-6, IL-8, and TNF-alpha all were higher in septic (median values: 1620, 331, and 22 pg/mL, respectively) than in nonseptic neonates (median values: 42, 63, and 13 pg/mL, respectively). In the group with sepsis, the degree of reactive hyperemia correlated to log IL-6 (r = 0.80) and log IL-8 values (r = 0.71).

CONCLUSION

Newborn infants with septicemia have increased reactive hyperemia and elevated cytokine levels very early in their disease. Reactive hyperemia in skin can be analyzed at the bedside and noninvasively and therefore may serve as an additional diagnostic tool in neonatal sepsis.

Capillary refill time in term neonates: bedside assessment

Capillary refill time (CRT) is yet to be established as a specific clinical sign of peripheral circulation in neonates. This study was conducted to assess the influence of four body sites used for measurement, interobserver variability, sex, birth weight, age at assessment and room temperature on CRT recorded in healthy term neonates, at bedside. Two observers measured CRT in four different body sites (forehead, chest, palm and heel) of each of 155 healthy term neonates. Significant differences occurred between the mean CRT recorded by the two observers in forehead (mean +/- SD: 2.62 +/- 0.8 s and 1.88 +/- 0.57 s; p < 0.001), palm (2.99 +/- 0.61 s and 2.75 +/- 1.12 s; p < 0.05) and heel (3.08 +/- 0.79 s and 4.24 +/- 1.84 s; p < 0.001). Only CRT in chest (2.7 +/- 0.42 s and 2.62 +/- 0.74 s) produced no significant differences in the means with a statistically significant and clinically fair, but not strong, interobserver agreement (r = 0.4; p < 0.001). No significant associations occurred between CRT and sex or birth weight. The associations of chest CRT with age at assessment (r = -0.23; p < 0.01) and room temperature (r = 0.27; p < 0.01) were clinically not important. In conclusion, CRT in neonates needs to be validated further before it can be useful as a specific clinical sign of peripheral circulation.