Septic shock, a prevalent critical condition in intensive care units (ICU) and a major cause of patient mortality, is fundamentally attributed to microcirculatory dysfunction. Traditional macrocirculatory parameters are often insufficiently sensitive to reflect microcirculatory status. Consequently monitoring peripheral microcirculatory function holds crucial significance for assessing disease progression and evaluating therapeutic efficacy in septic shock. The peripheral perfusion index (PPI), obtained from a standard pulse oximeter, is based on photoplethysmography (PPG). It calculates the differential absorption of red and infrared light emitted by the sensor between pulsatile arterial blood and non-pulsatile tissue, enabling real-time reflection of peripheral perfusion and thus providing non-invasive, continuous monitoring of microcirculatory function. Although often overlooked compared to other ICU monitoring parameters, PPI has demonstrated notable clinical advances in septic shock management. Specifically, in early identification, PPI combined with sequential organ failure assessment (SOFA) predicts disease progression, with its dynamic changes further aiding prognosis assessment. During fluid resuscitation, it guides fluid responsiveness evaluation and serves as a therapeutic target to optimize strategies. In circulatory support, it assists in determining vasoactive drug initiation timing and dosage titration. Additionally, PPI aids mechanical ventilation weaning and organ dysfunction evaluation. This article reviews the principles, influencing factors, and clinical application advances of PPI in septic shock, aiming to provide clinicians with a basis for individualized intervention, improved patient outcomes, and the advancement of precision medicine in septic shock management.
Humans ; Shock, Septic/therapy* ; Microcirculation ; Perfusion Index ; Prognosis ; Photoplethysmography

OBJECTIVE: To observe the correlation between the four limbs perfusion index (PI) and blood lactic acid in patients with neurosis, and evaluate the predictive value of PI on microcirculation perfusion metabolic disorder in patients with neurosis. METHODS: A prospective observational study was conducted. Adult patients admitted to the department of neurological intensive care unit (NICU) of the First Affiliated Hospital of Xinjiang Medical University from July 1 to August 20 in 2020 were enrolled. Under the condition of indoor temperature controlled at 25 centigrade, all patients were placed in the supine position, and the blood pressure, heart rate, PI of both fingers and thumb toes and arterial blood lactic acid were measured within 24 hours and 24-48 hours after NICU. The difference of four limbs PI at different time periods and its correlation with lactic acid were compared. Receiver operator characteristic curve (ROC curve) was used to evaluate the predictive value of four limbs PI on patients with microcirculatory perfusion metabolic disorder. RESULTS: A total of 44 patients with neurosis were enrolled, including 28 males and 16 females; average age (61.2±16.5) years old. There were no significant differences in PI of the left index finger and the right index finger [2.57 (1.44, 4.79) vs. 2.70 (1.25, 5.33)], PI of the left toe and the right toe [2.09 (0.85, 4.76) vs. 1.88 (0.74, 4.32)] within 24 hours after entering the NICU, and the PI of the left index finger and the right index finger [3.17 (1.49, 5.07) vs. 3.14 (1.33, 5.36)], PI of the left toe and the right toe [2.07 (0.75, 5.20) vs. 2.07 (0.68, 4.67)] at 24-48 hours after NICU admission (all P > 0.05). However, compared to the PI of the upper and lower limbs on the same side, except for the 24-48 hours after ICU of the PI difference between the left index finger and the left toe (P > 0.05), the PI of the toe was lower than that of the index finger at the other time periods (all P < 0.05). The correlation analysis showed that the PI value of four limbs of patients in both time periods were significantly negatively correlated with arterial blood lactic acid (the r values of the left index finger, the right index finger, the left toe and the right toe were -0.549, -0.482, -0.392 and -0.343 respectively within 24 hours after entering the NICU; the r values of the left index finger, the right index finger, the left toe and the right toe were -0.331, -0.292, -0.402 and -0.442 respectively after entering the NICU 24-48 hours, all P < 0.05). Taking lactic acid ≥ 2 mmol/L as the diagnostic standard for metabolic disorder of microcirculation perfusion (total 27 times, accounting for 30.7%). The efficacy of four limbs PI in predicting microcirculation perfusion metabolic disorder were compared. ROC curve analysis showed that the area under the curve (AUC) and 95% confidence interval (95%CI) of left index finger, right index finger, left toe and right toe predicting microcirculation perfusion metabolic disorder were 0.729 (0.609-0.850), 0.767 (0.662-0.871), 0.722 (0.609-0.835), 0.718 (0.593-0.842), respectively. There was no significant difference in AUC compare with each other (all P > 0.05). The cut-off value of PI of right index finger for predicting microcirculation perfusion metabolic disorder was 2.46, the sensitivity was 70.4%, the specificity was 75.4%, the positive likelihood ratio was 2.86, and the negative likelihood ratio was 0.30. CONCLUSIONS There are no significant differences in PI of bilateral index fingers, bilateral toes in patients with neurosis. However, unilateral upper and lower limbs showed lower PI in the toe than in the index finger. There is a significantly negatively correlation between PI and arterial blood lactic acid in all four limbs. PI can predict the metabolic disorder of microcirculation perfusion, and its cut-off value is 2.46.
Adult ; Female ; Male ; Humans ; Middle Aged ; Aged ; Lactic Acid ; Microcirculation ; Perfusion Index ; Lower Extremity ; Area Under Curve ; Nervous System Diseases

INTRODUCTION: Balanced general anesthesia technique is a popular choice for induction because it can minimize potential side effects from individual drugs when otherwise used alone. However, hypotension is still a common occurrence during induction. Perfusion Index (PI) has been used as a measure of systemic vascular resistance and has shown to predict hypotension after regional anesthesia and propofol induction. This study aimed to determine whether baseline PI can predict hypotension following balanced general anesthesia induction and determine a cut-off value where hypotension is expected to occur. METHODS: Thirty-five ASA I/II adults for elective surgery under general anesthesia were enrolled. Heart rate, blood pressure and PI were measured every minute from baseline to 5 minutes following induction and 10 minutes after endotracheal intubation. Hypotension was defined as fall in systolic BP (SBP) by >30% of baseline and/or mean arterial pressure (MAP) to <60 mmHg. Severe hypotension (MAP of <55 mm Hg) was treated. RESULTS: No hypotension was observed in the first 5 minutes. Within 10 minutes, hypotension occurred in 8.6% by SBP criterion and 2.6% by MAP criterion. Within 15 minutes, hypotension was seen in 5.7% by SBP and MAP criterion, respectively. PI showed very low (r < 0.2) to low (r = 0.2 to 0.39), negative to positive and insignificant correlation (p > 0.05) with hypotension whether using SBP or MAP criterion and whether observed at 10 or 15 minutes of anesthesia induction. The Area under the ROC curve is 0.397, 95% CI [0 .126, 0.667], p = 0.431. CONCLUSION This study lends inconclusive evidence on the usefulness of Innovo Deluxe Fingertip Pulse Oximeter with Plethysmograph and Perfusion Index to predict intraoperative hypotension following balanced general anesthesia induction for this sample of patients. However, there was a positive, moderate (r=0.538, 0.501 and 0.469) and significant (p<0.05) correlation between perfusion index and SBP, Diastolic BP and MAP, respectively.
oximetry ; hypotension ; Anesthesia, General ; arterial pressure ; blood pressure ; Perfusion index

Peripheral artery disease (PAD) is the most frequent cause of reduced perfusion in peripheral arteries. Patients with PAD often have manifestations of atherosclerosis of the lower limb, although both symptomatic and asymptomatic disease is common. The clinical signs of PAD can differ in diabetic and non-diabetic patients. Diabetic patients are at high risk for PAD characterized by symptoms of intermittent claudication or critical limb ischemia. However, the majority of PAD patients are clinically asymptomatic. In addition to history taking, physical examinations including inspection of the skin, palpation of leg and foot pulses, and determination of the ankle-brachial index (ABI) are considered for diagnosis of PAD. The ABI measurement is the easiest and most common investigative technique for PAD. For hemodynamic assessment, additional diagnostic modalities could be considered.
Ankle Brachial Index ; Arteries ; Asymptomatic Diseases ; Atherosclerosis ; Cardiology ; Diabetes Mellitus ; Diagnosis ; Extremities ; Foot ; Heart ; Hemodynamics ; Humans ; Intermittent Claudication ; Investigative Techniques ; Ischemia ; Leg ; Lower Extremity ; Palpation ; Perfusion ; Peripheral Arterial Disease ; Physical Examination ; Skin

Renal cortical necrosis (RCN) is patchy or diffuse ischemic destruction of the renal cortex caused by significantly reduced renal arterial perfusion. It is a rare cause of acute kidney injury (AKI) and is associated with high mortality. Here, we review the case of RCN in a 15-year-old boy who developed AKI. A 15-year-old boy was referred to our hospital from a local hospital due to a sharp decrease in his renal function. He presented with acute flank pain, nausea with vomiting, and oliguria for the past two days. He had taken a single dose of antihistamine for nasal congestion. At our hospital, his peak blood pressure was 148/83 mmHg and he had a high body mass index of 32.9 kg/m². The laboratory data showed a blood urea nitrogen (BUN) of 28.4 mg/dL, a creatinine of 4.26 mg/dL, and a glomerular filtration rate estimated from the serum cystatin C of 20.2 mL/min/1.73m². Proteinuria (spot urine protein to creatinine ratio 1.66) with pyuria was observed. Kidney sonography showed parenchymal swelling and increased renal echogenicity. Due to rapidly progressing nephritis, steroid pulse therapy (750 mg/IV) was done on the second day of his admission and the patient showed complete recovery with normal renal function. However, the kidney biopsy findings revealed renal cortical hemorrhagic necrosis. Multifocal, relatively well-circumscribed, hemorrhagic necrotic areas (about 25%) were detected in the tubulointerstitium. Although RCN is an unusual cause of AKI, especially in children, pediatricians should consider the possibility of RCN when evaluating patients with rapidly decreasing renal function.
Acute Kidney Injury ; Adolescent ; Biopsy ; Blood Pressure ; Blood Urea Nitrogen ; Body Mass Index ; Child ; Creatinine ; Cystatin C ; Estrogens, Conjugated (USP) ; Flank Pain ; Glomerular Filtration Rate ; Humans ; Kidney ; Kidney Cortex Necrosis ; Male ; Mortality ; Nausea ; Necrosis ; Nephritis ; Obesity ; Oliguria ; Perfusion ; Proteinuria ; Pyuria ; Vomiting

Aortoiliac occlusive disease (AIOD), especially proximal to the transplant artery, in kidney transplant patient activates the renin-angiotensin-aldosterone system by limiting graft renal perfusion and causes symptoms that can occur with transplant renal artery stenosis (TRAS) such as refractory hypertension, water retention, and graft renal dysfunction. Immediate clinical suspicion is difficult due to the nature of the progressive disease unlike TRAS. Herein, we present an interesting case of bilateral common iliac artery occlusion (AIOD, TASC II, type C) that manifested as uncontrolled blood pressure and decreased allograft function in a patient who had kidney transplant 17 years ago. The patient was successfully diagnosed with duplex scan, ankle-brachial index (ABI) and computed tomography angiography and treated with percutaneous luminal angioplasty and stent graft insertion.
Allografts ; Angiography ; Angioplasty ; Ankle Brachial Index ; Arteries ; Blood Pressure ; Blood Vessel Prosthesis ; Humans ; Hypertension ; Iliac Artery ; Kidney Transplantation ; Kidney ; Perfusion ; Phenobarbital ; Renal Artery Obstruction ; Renin-Angiotensin System ; Transplants ; Water

BACKGROUND/AIMS: To evaluate the geographic and demographic variabilities of the quantitative parameters of computed tomography perfusion (CTP) of the left ventricular (LV) myocardium in patients with normal coronary artery on computed tomography angiography (CTA). METHODS: From a multicenter CTP registry of stress and static computed tomography, we retrospectively recruited 113 patients (mean age, 60 years; 57 men) without perfusion defect on visual assessment and minimal (< 20% of diameter stenosis) or no coronary artery disease on CTA. Using semiautomatic analysis software, quantitative parameters of the LV myocardium, including the myocardial attenuation in stress and rest phases, transmural perfusion ratio (TPR), and myocardial perfusion reserve index (MPRI), were evaluated in 16 myocardial segments. RESULTS: In the lateral wall of the LV myocardium, all quantitative parameters except for MPRI were significantly higher compared with those in the other walls. The MPRI showed consistent values in all myocardial walls (anterior to lateral wall: range, 25% to 27%; p = 0.401). At the basal level of the myocardium, all quantitative parameters were significantly lower than those at the mid- and apical levels. Compared with men, women had significantly higher values of myocardial attenuation and TPR. Age, body mass index, and Framingham risk score were significantly associated with the difference in myocardial attenuation. CONCLUSIONS: Geographic and demographic variabilities of quantitative parameters in stress myocardial CTP exist in healthy subjects without significant coronary artery disease. This information may be helpful when assessing myocardial perfusion defects in CTP.
Angiography ; Body Mass Index ; Coronary Artery Disease ; Coronary Vessels ; Cytidine Triphosphate ; Female ; Healthy Volunteers ; Humans ; Male ; Myocardium ; Perfusion* ; Retrospective Studies

OBJECTIVE: We aimed to evaluate the time efficiency and diagnostic accuracy of automated myocardial computed tomography perfusion (CTP) image analysis software. MATERIALS AND METHODS: 320-row CTP was performed in 30 patients, and analyses were conducted independently by three different blinded readers by the use of two recent software releases (version 4.6 and novel version 4.71GR001, Toshiba, Tokyo, Japan). Analysis times were compared, and automated epi- and endocardial contour detection was subjectively rated in five categories (excellent, good, fair, poor and very poor). As semi-quantitative perfusion parameters, myocardial attenuation and transmural perfusion ratio (TPR) were calculated for each myocardial segment and agreement was tested by using the intraclass correlation coefficient (ICC). Conventional coronary angiography served as reference standard. RESULTS: The analysis time was significantly reduced with the novel automated software version as compared with the former release (Reader 1: 43:08 +/- 11:39 min vs. 09:47 +/- 04:51 min, Reader 2: 42:07 +/- 06:44 min vs. 09:42 +/- 02:50 min and Reader 3: 21:38 +/- 3:44 min vs. 07:34 +/- 02:12 min; p < 0.001 for all). Epi- and endocardial contour detection for the novel software was rated to be significantly better (p < 0.001) than with the former software. ICCs demonstrated strong agreement (> or = 0.75) for myocardial attenuation in 93% and for TPR in 82%. Diagnostic accuracy for the two software versions was not significantly different (p = 0.169) as compared with conventional coronary angiography. CONCLUSION: The novel automated CTP analysis software offers enhanced time efficiency with an improvement by a factor of about four, while maintaining diagnostic accuracy.
Aged ; Analysis of Variance ; Body Mass Index ; Coronary Angiography ; Coronary Artery Disease/*radiography ; *Efficiency, Organizational ; Female ; Humans ; Male ; Middle Aged ; Myocardial Perfusion Imaging/*methods ; Pattern Recognition, Automated/*methods ; Prospective Studies ; Radiographic Image Interpretation, Computer-Assisted/*methods ; *Software ; Statistics, Nonparametric ; Time Factors ; Tomography, X-Ray Computed/*methods

PURPOSE: Prosthetic-based breast reconstruction is performed with increasing frequency in the United States. Major mastectomy skin flap necrosis is a significant complication with outcomes ranging from poor aesthetic appearance to reconstructive failure. The present study aimed to explore the interactions between intraoperative fill and other risk factors on the incidence of flap necrosis in patients undergoing mastectomy with immediate expander/implant-based reconstruction. METHODS: A retrospective review of 966 consecutive patients (1,409 breasts) who underwent skin or nipple sparing mastectomy with immediate tissue expander reconstruction at a single institution was conducted. Age, body mass index, hypertension, smoking status, premastectomy and postmastectomy radiation, acellular dermal matrix use, and application of the tumescent mastectomy technique were analyzed as potential predictors of flap necrosis both independently and as synergistic variables with high intraoperative fill. The following three measures of interaction were calculated: relative excess risk due to interaction, attributable proportion of risk due to interaction, and synergy index (SI). RESULTS: Intraoperative tissue expander fill volume was high (> or =66.7% of the maximum volume) in 40.9% (576 of 1,409 breasts) of cases. The unadjusted flap necrosis rate was greater in the high intraoperative fill cohort than in the low fill cohort (10.4% vs. 7.1%, p=0.027). Multivariate logistic regression did not identify high intraoperative fill volume as an independent risk factor for flap necrosis (odds ratio 1.442, 95% confidence interval 0.973-2.137, p=0.068). However, four risk factors were identified that interacted significantly with intraoperative fill volume, namely tumescence, age, hypertension, and obesity. The SI, or the departure from additive risks, was largest for tumescence (SI, 25.3), followed by hypertension (SI, 2.39), obesity (SI, 2.28), and age older than 50 years (SI, 1.17). CONCLUSION: In the postmastectomy, hypovascular milieu, multiple risk factors decreasing flap perfusion interact with high intraoperative fill volume to cross a threshold and synergistically increase the risk of flap necrosis.
Acellular Dermis ; Body Mass Index ; Cohort Studies ; Female ; Humans ; Hypertension ; Incidence ; Logistic Models ; Mammaplasty ; Mastectomy* ; Necrosis* ; Nipples ; Obesity ; Perfusion ; Retrospective Studies ; Risk Factors ; Skin ; Smoke ; Smoking ; Tissue Expansion Devices ; United States

BACKGROUND: The ankle brachial pressure index (ABI) is a simple, useful method for diagnosing peripheral artery disease (PAD). Although the ABI is an objective diagnostic method, it has limited reliability in certain scenarios. The aim of the present study was to determine the accuracy and reliability of the toe brachial index (TBI) as a diagnostic tool for detecting stenosis in PAD, associated with normal or low ABI values. METHODS: ABI and TBI values were measured in 15 patients with diabetic gangrene who were suspected of having lower extremity arterial insufficiency. The ABI and TBI values were measured using a device that allowed the simultaneous measurement of systolic blood pressure in the upper and lower extremities. In addition, the ABI and TBI values were compared pre- and post-angiography. RESULTS: Patients with an ABI of 0.9-1.3 showed almost no difference between the 2 measurements. The patients with TBI >0.6 had no arterial insufficiency. The patients with TBI <0.6 required vascular intervention with ballooning. After the angiography, the gangrenous wounds decreased in size more rapidly than they did prior to the intervention. CONCLUSIONS: Our findings suggest that TBI is the method of choice for evaluating lower limb perfusion disorders. This result requires further studies of TBI in a larger number of patients. Future long-term studies should therefore evaluate the utility of TBI as a means of screening for PAD and the present findings should be regarded as preliminary outcomes.
Angiography ; Animals ; Ankle ; Ankle Brachial Index ; Blood Pressure ; Constriction, Pathologic ; Gangrene ; Humans ; Lower Extremity ; Mass Screening ; Perfusion ; Peripheral Arterial Disease