The prognostic value of elevated neutrophil-lymphocyte ratio for cardiac surgery-associated acute kidney injury: A systematic review and meta-analysis.

BACKGROUND: Patients undergoing cardiac surgery are at significant risk of developing postoperative acute kidney injury (AKI). Neutrophil-lymphocyte ratio (NLR) is a widely available inflammatory biomarker which may be of prognostic value in this setting. METHODS: We conducted a systematic review and meta-analysis of studies reporting associations between perioperative NLR with postoperative AKI. We searched Medline, Embase and the Cochrane Library, without language restriction, from inception to May 2022 for relevant studies. We meta-analysed the reported odds ratios (ORs) with 95% confidence intervals (CIs) for both elevated preoperative and postoperative NLR with risk of postoperative AKI and need for renal replacement therapy (RRT). We conducted a meta-regression to explore inter-study statistical heterogeneity. RESULTS: Twelve studies involving 10,724 participants undergoing cardiac surgery were included, with eight studies being deemed at high risk of bias using PROBAST modelling. We found statistically significant associations between elevated preoperative NLR and postoperative AKI (OR 1.45, 95% CI 1.18-1.77), as well as postoperative need for RRT (OR 2.37, 95% CI 1.50-3.72). Postoperative NLR measurements were not of prognostic significance. CONCLUSIONS: Elevated preoperative NLR is a reliable inflammatory biomarker for predicting AKI following cardiac surgery.

Perioperative Neutrophil-Lymphocyte Ratio Predicts Mortality After Cardiac Surgery: Systematic Review and Meta-Analysis.

OBJECTIVES: Neutrophil-lymphocyte ratio (NLR) is an inflammatory biomarker that has been evaluated across a variety of surgical disciplines and is widely predictive of poor postoperative outcome, but its value in cardiac surgery is unclear. The authors did this systematic review and meta-analysis to determine the impact of elevated perioperative NLR on survival after cardiac surgery. DESIGN: Systematic review and meta-analysis of study-level data. SETTING: Multiple hospitals involved in an international pool of studies. PARTICIPANTS: Adults undergoing cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The authors searched multiple databases from inception until November 2020. They generated summary hazard ratios (HR) and odds ratios (OR) for the association of elevated preoperative NLR with long-term and short-term mortality following cardiac surgery. They separately reported on elevated postoperative NLR. Between-study heterogeneity was explored using metaregression. The authors included 12 studies involving 13,262 patients undergoing cardiac surgery. Elevated preoperative NLR was associated with worse long-term (>30 days) (hazard ratio [HR] 1.56; 95% CI [confidence interval], 1.18-2.06; 8 studies) and short-term (<30 days) mortality (OR 3.18; 95% CI, 1.90-5.30; 7 studies). One study reported the association of elevated postoperative NLR with long-term mortality (HR 8.58; 95% CI, 2.55-28.85). There was considerable between-study heterogeneity for the analysis of long-term mortality (I2 statistic 94.39%), which mostly was explained by study-level variables, such as the number of variables adjusted for by included studies and how many of these significantly increased the risk of long-term mortality, high risk of bias, and number of study centers, as well as participant level factors, such as average participant age and hypertension prevalence. CONCLUSIONS: Perioperative NLR is an independent predictor of short-term and long-term postoperative mortality following cardiac surgery. Further research is required to determine which patient-level factors modify the prognostic value of NLR and to evaluate its role in routine clinical practice.

Development of a Frailty Index from Routine Hospital Data in Perioperative and Critical Care.

BACKGROUND/OBJECTIVES: Frailty is common in surgical and intensive care unit (ICU) populations, yet it is not routinely measured. Frailty indices are able to quantify this condition across a range of health deficits. We aimed to develop a frailty index (FI) from routinely collected hospital data in a surgical and ICU population. DESIGN: Prospective observational single-center cohort study. SETTING: Tertiary referral metropolitan Australian hospital. PARTICIPANTS: A total of 336 individuals aged 65 and older undergoing surgery or aged 50 and older admitted to the ICU. MEASUREMENTS: Routine admission health data were used to derive an FI comprising 36 health deficits. We examined the FI correlation with existing frailty tools (Clinical Frailty Scale [CFS] and Edmonton Frail Scale [EFS]) and assessed its predictive ability for negative outcomes including 30-day mortality. RESULTS: Median FI was .17 (interquartile range [IQR]) = .10-.24) for ICU patients and .17 (IQR = .11-.25) for surgical patients; maximum FI was .58, and 25% (95% confidence interval [CI] = 10.4-29.6) of patients overall were diagnosed with frailty (FI score ≥.25). Correlation was strong between the FI and the EFS: ρ = .76 (95% CI = .70-.83) for ICU patients and .71 (95% CI = .64-.78) for surgical patients, and the CFS was .77 (95% CI = .70-.84) for ICU patients and .72 (95% CI = .65-.79) for surgical patients. The FI had good discriminative ability for prediction of 30-day mortality in ICU patients (multivariate odds ratio for each increase in FI of .1 = 2.04 [95% CI = 1.19-3.48]), comparable with the performance of the Acute Physiology and Chronic Health Evaluation III score (ICU patients) and the Portsmouth Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity score (surgical patients). CONCLUSION: It is feasible to construct an FI from hospital admission data in a cohort of critically ill and surgical patients.

Accuracy of the Clinical Frailty Scale for perioperative frailty screening: a prospective observational study.

PURPOSE: Perioperative frailty increases postoperative complications, mortality, and new functional dependence. Despite this, routine perioperative frailty screening is not widespread. We aimed to assess the accuracy of the Clinical Frailty Scale (CFS) as a screening tool prior to anesthesia, and to determine which health domains are affected by frailty. METHODS: In a prospective, single-centre observational study, we enrolled 218 patients aged ≥ 65 yr undergoing elective and emergency surgery. The screening performance of the CFS was compared with the Edmonton Frail Scale, including the effect in individual frailty domains, and outcomes including discharge location and mortality. RESULTS: The median [interquartile range] age of the enrolled subjects was 74 [69-80] yr and 24% of the patients were frail. The CFS and Edmonton scales were highly correlated (Spearman correlation coefficient, 0.81; 95% confidence interval [CI], 0.77 to 0.86), and in substantial agreement (kappa coefficient, 0.76; 95% CI, 0.70 to 0.81), with an area under the receiver operating characteristic curve of 0.91 (95% CI, 0.86 to 0.94) indicating excellent discrimination for the CFS in predicting frailty status based on the Edmonton scale. Frail patients had higher 30-day mortality (odds ratio, 5.26; 95% CI, 1.28 to 21.62), and were less likely to be discharged home. Frail patients had poorer health throughout frailty domains, including functional dependence (42% of frail vs 4% of non-frail patients; P < 0.001), malnutrition (48% vs 19%, P < 0.001), and poor physical performance (47% vs 7%, P < 0.001). CONCLUSION: The CFS is a valid and accurate tool to screen for perioperative frailty, which encompasses the spectrum of health-related domains.

RéSUMé: OBJECTIF: La fragilité périopératoire augmente les complications postopératoires, la mortalité et une nouvelle dépendance fonctionnelle. Le dépistage de routine de la fragilité périopératoire n'est cependant pas une pratique répandue. Nous avions pour objectif d'évaluer la précision de l'échelle de mesure de fragilité CFS (pour Clinical Frailty Scale) comme outil de dépistage préanesthésique et de déterminer quels domaines de la santé étaient affectés par la fragilité. MéTHODE: Nous avons recruté 218 patients âgés de plus de 65 ans et subissant une chirurgie non urgente ou urgente dans notre étude observationnelle prospective et monocentrique. Les résultats du dépistage de la CFS ont été comparés à l'échelle de fragilité d'Edmonton (Edmonton Frail Scale), y compris en ce qui a trait à l'effet de la fragilité sur les domaines individuels de fragilité et aux résultats tels que la destination au congé et la mortalité. RéSULTATS: L'âge médian [écart interquartile] des patients recrutés était de 74 [69­80] ans et 24 % des patients étaient fragiles. Les échelles CFS et d'Edmonton avaient une forte corrélation (coefficient de corrélation de Spearman, 0,81; intervalle de confiance [IC] 95 %, 0,77 à 0,86) et étaient en accord substantiel (coefficient kappa, 0,76; IC 95 %, 0,70 à 0,81), avec une surface sous la courbe de fonction d'efficacité de l'observateur de 0,91 (IC 95 %, 0,86 à 0,94), indiquant une discrimination excellente de la CFS pour prédire l'état de fragilité fondé sur l'échelle d'Edmonton. Les patients fragiles souffraient d'une mortalité à 30 jours plus élevée (rapport de cotes, 5,26; IC 95 %, 1,28 à 21,62) et il était moins probable qu'ils reçoivent leur congé de l'hôpital à la maison. Les patients fragiles étaient en moins bonne santé dans tous les domaines de fragilité, notamment en dépendance fonctionnelle (42 % des patients fragiles vs 4 % des patients non fragiles; P < 0,001), en malnutrition (48 % vs 19 %, P < 0,001) et en mauvaise performance physique (47 % vs 7 %, P < 0,001). CONCLUSION: L'échelle CFS constitue un outil valable et précis pour dépister la fragilité périopératoire, qui englobe l'éventail des domaines liés à la santé.

Protocol for a prospective observational study to develop a frailty index for use in perioperative and critical care.

INTRODUCTION: Frailty is of increasing importance to perioperative and critical care medicine, as the proportion of older patients increases globally. Evidence continues to emerge of the considerable impact frailty has on adverse outcomes from both surgery and critical care, which has led to a proliferation of different frailty measurement tools in recent years. Despite this, there remains a lack of easily implemented, comprehensive frailty assessment tools specific to these complex populations. Development of a frailty index using routinely collected hospital data, able to leverage the automated aspects of an electronic medical record, would aid risk stratification and benefit clinicians and patients alike. METHODS AND ANALYSIS: This is a prospective observational study. 150 intensive care unit (ICU) patients aged ≥50 years and 200 surgical patients aged ≥65 years will be enrolled. The primary objective is to develop a frailty index. Secondary objectives include assessing its ability to predict in-hospital mortality and/or discharge to a new non-home location; the performance of the frailty index in predicting postoperative and ICU complications, as well as health-related quality of life at 6 months; to compare the performance of the frailty index against existing frailty measurement and risk stratification tools; and to assess its modification by patients' health assets. ETHICS AND DISSEMINATION: This study has been approved by the Melbourne Health Human Research Ethics Committee(20 January 2017, HREC/16/MH/321). Dissemination will be via international and national anaesthetic and critical care conferences, and publication in the peer-reviewed literature.