The perfusion index is a useful screening tool for peripheral artery disease

Initial 24-h perfusion index of ICU admission is associated with acute kidney injury in perioperative critically ill patients: A retrospective cohort analysis

Background

The relationship between perfusion index (PI) and organ dysfunction in patients in the intensive care unit (ICU) is not clear. This study aimed to explore the relationship between PI and renal function in the perioperative critical care setting and evaluate the predictive efficiency of PI on patients with acute kidney injury (AKI) in the ICU.

Methods

This retrospective analysis involved 12,979 patients who had undergone an operation and were admitted to the ICU in Peking Union Medical College Hospital from January 2014 to December 2019. The distribution of average PI in the first 24 h after ICU admission and its correlation with AKI was calculated by Cox regression. Receiver operating characteristic (ROC) curves were generated to compare the ability of PI, mean arterial pressure (MAP), creatinine, blood urea nitrogen (BUN), and central venous pressure (CVP) to discriminate AKI in the first 48 h in all perioperative critically ill patients.

Results

Average PI in the first 24 h served as an independent protective factor of AKI (Odds ratio [OR]=0.786, 95% confidence interval [CI]: 0.704-0.873, P <0.0001). With a decrease in PI by one unit, the incidence of AKI increased 1.74 times. Among the variables explored for the prediction of AKI (PI, MAP, creatine, BUN, and CVP), PI yielded the highest area under the ROC curve, with a sensitivity of 64.34% and specificity of 70.14%. A cut-off value of PI ≤2.12 could be used to predict AKI according to the Youden index. Moreover, patients in the low PI group (PI ≤2.12) exhibited a marked creatine elevation at 24-48 h with a slower decrease compared with those in the high PI group (PI >2.12).

Conclusions

As a local blood flow indicator, the initial 24-h average PI for perioperative critically ill patients can predict AKI during their first 120 h in the ICU.

Perfusion index for early identification of regional anesthesia effectiveness: a narrative review

Regional anesthesia (RA) is a common and irreplaceable technique in clinical, which can be used in different surgery sites and control of acute and chronic pain, especially for outpatients, pediatrics and the elderly. RA demands are increasing during COVID-19 pandemic because many surgeries could be performed under RA to reduce the risk of cross-infection between patients and health care workers. Early and accurate identification of the effects of RA can help physicians make timely decisions about whether to supplement analgesics or switch to general anesthesia, which will save time and improve patient satisfaction in a busy operating room. Perfusion index (PI) is a parameter derived from photoplethysmography (PPG) and represents the ratio of pulsatile and non-pulsatile blood flow at monitoring sites. It reflects local perfusion and is mainly affected by stroke volume and vascular tone. With characteristics of non-invasive, rapid, simple, and objective, PI is widely used in clinical practice, such as fluid responsiveness prediction, nociceptive assessment, etc. Recently, many studies have assessed the accuracy of PI in early prediction of RA success, including brachial plexus block, sciatic nerve block, neuraxial anesthesia, paravertebral block, caudal block and stellate ganglion block. Successful RA often parallels increased PI. In this narrative review, we describe the principles and influencing factors of PI, and introduce the effects of PI on early identification of RA effectiveness.

Decreased peripheral perfusion measured by perfusion index is a novel indicator for cardiovascular death in patients with type 2 diabetes and established cardiovascular disease

Cardiovascular disease (CVD) is still the major cause of mortality in patients with type 2 diabetes. Despite of recent therapies, mortality and resources spent on healthcare due to CVD is still important problem. Thus, appropriate markers are needed to predict poor outcomes. Therefore, we investigated the role of peripheral perfusion as an indicator for cardiovascular death in patients with type 2 diabetes and established CVD. This retrospective cohort study included 1080 patients with type 2 diabetes and history of CVD recruited from the outpatient clinic at Matsushita Memorial Hospital in Osaka, Japan. Peripheral perfusion is assessed using the perfusion index (PI), which represents the level of circulation through peripheral tissues. The median age and PI values were 74 years (range: 67-79 years) and 2.6% (range: 1.1-4.3%), respectively. During follow-up duration, 60 patients died due to CVD. The adjusted Cox regression analysis demonstrated that the risk of developing cardiovascular death was higher in the first quartile (Hazard ratio, 6.23; 95% CI, 2.28 to 22.12) or second quartile (Hazard ratio, 3.04; 95% CI, 1.46 to 6.85) of PI than that in the highest quartile (fourth quartile) of PI. PI (per 1% decrease) was associated with the development of cardiovascular death (Hazard ratio, 1.39; 95% CI, 1.16 to 1.68). PI could be a novel indicator of cardiovascular death in patients with type 2 diabetes and established CVD.

Prognostic performance of peripheral perfusion index and shock index combined with ESI to predict hospital outcome

INTRODUCTION

Peripheral perfusion index (PPI) and shock index (SI) are considered valuable predictors of hospital outcome and mortality in various operative and intensive care settings. In the present study, we evaluated the prognostic capabilities of these parameters for performing emergency department (ED) triage, as represented by the emergency severity index (ESI).

METHODS

This prospective cross-sectional study included 367 patients aged older than 18 years who visited the ED of a tertiary referral hospital. The ESI triage levels with PPI, SI, and other basic vital sign parameters were recorded for each patient. The hospital outcome of the patients at the end of the ED period, such as discharge, admission to the hospital and death were recorded.

RESULTS

A total of 367 patients (M/F: 178/189) admitted to the ED were categorized according to ESI and included in the study. A decrease in diastolic BP, SpO2 and PPI increased the likelihood of hospitalization and 30-day mortality. Based on univariate analysis, a significant improvement in performance was found by using age, diastolic BP, mean arterial pressure, SpO2, SI and PPI in terms of predicting high acuity level patients (ESI < 3). In the multivariable analysis only SpO2 and PPI were found to predict ESI < 3 patients.

CONCLUSION

Peripheral perfusion index and SI as novel triage instruments might provide useful information for predicting hospital admission and mortality in ED patients. The addition of these parameters to existing triage instruments such as ESI could enhance the triage specificity in unselected patients admitted to ED.

Decreased microcirculatory function measured by perfusion index is a novel indicator of diabetic kidney disease in patients with type 2 diabetes

AIMS/INTRODUCTION

Diabetic kidney disease has been considered as an important risk factor of cardiovascular disease. Chronic hypoxia is considered to be the main cause of renal injury. Diminished microcirculatory blood flow could be associated with hypoxia in the kidney. Whether diminished microcirculation is associated with diabetic kidney disease has not yet been reported. Here, we investigated the correlation between microcirculatory function and diabetic kidney disease in patients with type 2 diabetes.

MATERIALS AND METHODS

Our cross-sectional study included 574 patients who were admitted to Matsushita Memorial Hospital in Moriguchi, Japan, for type 2 diabetes. Microcirculatory function was assessed using the perfusion index (PI), which represents the level of circulation through peripheral tissues. We measured the PI for all patients.

RESULTS

The median age and PI values were 70 years (range 60-77 years) and 2.8% (range 1.6-4.8%). Multiple regression analyses showed that the PI independently correlated with the logarithm of urinary albumin excretion (P = 0.009) and estimated glomerular filtration rate (P = 0.005), respectively. Multiple logistic regression analyses showed that patients with systolic blood pressure (SBP) greater than the median and PI less than or equal to the median (high-low group) had a significantly increased odds of albuminuria compared with those with SBP less than or equal to the median and PI greater than the median (low-high group), and patients with SBP greater than the median and PI less than or equal to the median (high-low group) had a significantly increased odds of estimated glomerular filtration rate <60 mL/min per 1.73 m2 compared with those with SBP less than or equal to the median and PI greater than the median (low-high group) or SBP greater than the median and PI greater than the median (high-high group).

CONCLUSIONS

PI could be a novel indicator of diabetic kidney disease in patients with type 2 diabetes.

Peripheral perfusion, measured by perfusion index, is a novel indicator for renal events in patients with type 2 diabetes mellitus

Diabetic kidney disease (DKD) is one of the leading causes of end stage renal disease. Despite recent therapies, mortality due to DKD and resources spent on healthcare are important problems. Thus, appropriate markers are needed to predict renal outcomes. Therefore, we investigated the role of peripheral perfusion as an indicator for renal events in patients with type 2 diabetes mellitus. This retrospective cohort study included 566 patients who were admitted to Matsushita Memorial Hospital in Osaka, Japan for type 2 diabetes mellitus. Peripheral perfusion was assessed using perfusion index (PI), which represents the level of circulation through peripheral tissues and was measured on each toe using a Masimo SET Radical-7 (Masimo Corporation, Irvine, CA, USA) instrument. The duration of follow up was 3.0 years. The median age of patients was 70 years (IQR range: 61-77 years) and median PI value was 2.9% (IQR range: 1.8-4.8%). Multiple logistic regression analyses showed that PI (per 1% increase) was associated with an odds ratio of composite of end-stage renal disease (ESRD) and/or doubling of serum creatinine level; n = 40 (odds ratio 0.823 [95% CI: 0.680-0.970]), and composite of ESRD, doubling of serum creatinine level, and renal death and/or cardiovascular death; n = 44 (odds ratio 0.803 [95% CI: 0.665-0.944]). The factors which were statistically significant in univariate analysis and those known to be related factors for renal event were considered simultaneously as independent variables for multiple logistic regression analysis. PI can be a novel indicator for renal events in patients with type 2 diabetes mellitus.

Decreased microcirculatory function measured by perfusion index is predictive of cardiovascular death

BACKGROUND

The importance of microcirculation for adverse outcomes in the early phase of critical illnesses has been reported. Microcirculatory function is assessed using the perfusion index (PI), which represents the level of circulation through peripheral tissues. We investigated the correlation between PI and cardiovascular death to explore whether it can serve as a predictor of cardiovascular death.

METHODS AND RESULTS

This retrospective study included 2171 patients admitted to Matsushita Memorial Hospital in Osaka, Japan, for medical treatment. We measured PI for all patients. To examine the effects of PI on cardiovascular death, a Cox proportional hazard model was used. The median age and PI values were 72 years (range 63-79 years) and 2.7% (range 1.4-4.6%), respectively. During the 3927.7 person-years follow-up period, a total of 54 patients died due to cardiovascular disease. PI was positively correlated with BMI (P < 0.0001) and total cholesterol levels (P = 0.004). PI was negatively correlated with age (P < 0.0001), heart rate (P < 0.0001), and creatinine levels (P < 0.0001). Adjusted Cox regression analyses demonstrated that PI was associated with an increased hazard of cardiovascular death (hazard ratio 0.84; 95% CI; range 0.72-0.99). In addition, compared with patients with a high PI (> 3.7%), those with a low PI (≤ 2.0%) had a significantly increased risk of cardiovascular death. This low PI group had a hazard ratio of 3.49 (95% CI 1.73-7.82).

CONCLUSIONS

The PI is a valuable predictor for cardiovascular death in a clinical setting.