Peripheral Perfusion Index Research Articles

Prediction of mortality in COVID-19 through combing CT severity score with NEWS, qSOFA, or peripheral perfusion index.

IntroductionThe assessment of disease severity and the prediction of clinical outcomes at early disease stages can contribute to decreased mortality in patients with Coronavirus disease 2019 (COVID-19). This study was conducted to develop and validate a multivariable risk prediction model for mortality with using a combination of computed tomography severity score (CT-SS), national early warning score (NEWS), and quick sequential (sepsis-related) organ failure assessment (qSOFA) in COVID-19 patients.MethodsWe retrospectively collected medical data from 655 adult COVID-19 patients admitted to our hospital between July and November 2020. Data on demographics, clinical characteristics, and laboratory and radiological findings measured as part of standard care at admission were used to calculate NEWS, qSOFA score, CT-SS, peripheral perfusion index (PPI) and shock index (SI). Logistic regression and Cox proportional hazard models were used to predict mortality, which was our primary outcome. The predictive accuracy of distinct scoring systems was evaluated by the receiver-operating characteristic (ROC) curve analysis.ResultsThe median age was 50.0 years [333 males (50.8%), 322 females (49.2%)]. Higher NEWS and SI was associated with time-to-death within 90-days, whereas higher age, CT-SS and lower PPI were significantly associated with time-to-death within both 14 days and 90 days in the adjusted Cox regression model. The CT-SS predicted different mortality risk levels within each stratum of NEWS and qSOFA and improved the discrimination of mortality prediction models. Combining CT-SS with NEWS score yielded more accurate 14 days (DBA: −0.048, p = 0.002) and 90 days (DBA: −0.066, p < 0.001) mortality prediction.ConclusionCombining severity tools such as CT-SS, NEWS and qSOFA improves the accuracy of predicting mortality in patients with COVID-19. Inclusion of these tools in decision strategies might provide early detection of high-risk groups, avoid delayed medical attention, and improve patient outcomes.

Association between peripheral perfusion index and five vital signs in patients admitted to the emergency department

Association between peripheral perfusion index and five vital signs in patients admitted to the emergency department

Changes in peripheral perfusion index during intraoperative end-expiratory occlusion tests do not predict the response to fluid administration in patients undergoing lung protective ventilation.

The end-expiratory occlusion test (EEOT) may predict the response to fluid administration in patients undergoing lung-protective ventilation, but arterial catheter insertion is necessary to evaluate changes in stroke volume (SV). The peripheral perfusion index is a potential noninvasive alternative to evaluate SV. The aim of this study is to investigate whether changes in perfusion index during an intraoperative EEOT can predict the response to fluid administration in patients undergoing lung-protective ventilation (tidal volume 7ml/kg predicted body weight). Forty-one elective surgical patients were enrolled. The SV and perfusion index were recorded before (baseline), during a 40-s EEOT and after volume expansion (250ml of lactated Ringer's solution over 10min). Patients with an increase in SV greater than 10% after volume expansion were defined as responders. ΔPI (change in perfusion index between baseline and 20 (ΔPI20) or 40s (ΔPI40) after the beginning of EEOT were calculated using: ΔPI20 (%) = [(PI at 20s after EEOT beginning-PIbaseline)/PIbaseline] × 100, ΔPI40 (%) = [(PI at 40s after EEO beginning-PIbaseline)/PIbaseline] × 100). Sixteen patients were responders, and 25 were non-responders. The area under the receiver operating characteristics curves generated for ΔPI20 and ΔPI40 to predict response to a fluid challenge were 0.561 (95% CI 0.374-0.749) and 0.688 (95% CI 0.523-0.852), respectively. Changes in perfusion index during intraoperative EEOT in patients undergoing lung-protective ventilation (7ml/kg) were unable to predict the response to fluid administration.

Association of the intraoperative peripheral perfusion index with postoperative morbidity and mortality in acute surgical patients: a retrospective observational multicentre cohort study

BackgroundWe hypothesised that in acute high-risk surgical patients, a lower intraoperative peripheral perfusion index (PPI) would indicate a higher risk of postoperative complications and mortality. MethodsThis retrospective observational study included 1338 acute high-risk surgical patients from November 2017 until October 2018 at two University Hospitals in Denmark. Intraoperative PPI was the primary exposure variable and the primary outcome was severe postoperative complications defined as a Clavien–Dindo Class ≥III or death, within 30 days. Resultsintraoperative PPI was associated with severe postoperative complications or death: odds ratio (OR) 1.12 (95% confidence interval [CI] 1.05–1.19; P<0.001), with an association of intraoperative mean PPI ≤0.5 and PPI ≤1.5 with the primary outcome: OR 1.79 (95% CI 1.09–2.91; P=0.02) and OR 1.65 (95% CI 1.20–2.27; P=0.002), respectively. Each 15-min increase in intraoperative time spend with low PPI was associated with the primary outcome (per 15 min with PPI ≤0.5: OR 1.11 (95% CI 1.05–1.17; P<0.001) and with PPI ≤1.5: OR 1.06 (95% CI 1.02–1.09; P=0.002)). Thirty-day mortality in patients with PPI ≤0.5 was 19% vs 10% for PPI >0.5, P=0.003. If PPI was ≤1.5, 30-day mortality was 16% vs 8% in patients with a PPI >1.5 (P<0.001). In contrast, intraoperative mean MAP ≤65 mm Hg was not significantly associated with severe postoperative complications or death (OR 1.21 [95% CI 0.92–1.58; P=0.2]). ConclusionsLow intraoperative PPI was associated with severe postoperative complications or death in acute high-risk surgical patients. To guide intraoperative haemodynamic management, the PPI should be further investigated.

Acute hyperventilation increases oxygen consumption and decreases peripheral tissue perfusion in critically ill patients.

This study aimed to evaluate the effects of acute hyperventilation on central venous-to-arterial carbon dioxide tension difference (Pv-aCO2), central venous oxygen saturation (ScvO2), central venous-to-arterial CO2 difference/arterial-central venous O2 difference ratio (CO2GAP-Ratio), and peripheral perfusion index (PI) in hemodynamically stable critically ill patients. Fifty-four mechanically ventilated patients were evaluated. The cardiac index, Pv-aCO2, ScvO2, CO2GAP-Ratio, PI, and arterial and venous blood gas parameters were measured in the first set of measurements. Then, alveolar ventilation was increased by raising the respiratory rate (10 breaths/min). After a 30 min hyperventilation period, the second set of measurements was recorded. Acute hyperventilation induces an increase in Pv-aCO2 (from 3.87 ± 1.31 to 8.44 ± 1.81 mmHg, P < 0.001) and a decrease in ScvO2(from 71.78 ± 4.82 to 66.47 ± 5.74%, P < 0.001). The CO2GAP-Ratio was significantly increased(from 0.97 ± 0.40 to 1.74 ± 0.46, P < 0.001), and the PI showed a remarkable decrease caused by acute hyperventilation(from 1.82 ± 1.14 to 1.40 ± 0.99，P = 0.04). Hyperventilation-induced ∆_Pv-aCO2 was negatively correlated with ∆PaCO2(r = -0.572, P<0.001). The change in ∆_PaCO2 was correlated with ∆_ScvO2(r = 0.450, P<0.001). However, the left ventricular outflow tract velocity time integral (LVOT-VTI) remained unchanged during hyperventilation. Acute hyperventilation induced an increase in oxygen consumption and decreased peripheral tissue perfusion in patients. For critical care patients, it is necessary to pay attention to the influence of hyperventilation on peripheral tissue perfusion indices and oxygen consumption indices.

Assessment of Tissue Perfusion Using the Peripheral Perfusion Index and Lactate Clearance in Shock in Pediatric Patients.

Pediatric shock has a high mortality rate because many of the early clinical signs are subtle and have poor sensitivity and specificity. Pediatric shock was categorized either: compensated with normal blood pressure, poor skin perfusion (CRT >2 s, mottled, cool peripheries, peripheral cyanosis), weak peripheral pulse, age specific tachycardia, tachypnoea, and oliguria or decompensated with hypotension (SBP < 70 + (2× age in years) mm Hg and decreased mental status. The perfusion index is a non-invasive method for assessing peripheral perfusion and may be a useful marker for identifying shock early in pediatric patients. This prospective cohort study (November 2019 to August 2020) evaluated whether the perfusion index, lactate, and/or lactate clearance could predict mortality among pediatric shock patients. Fifty children (68% male) with shock underwent assessments at presentation to the emergency room to evaluate their heart rate, blood pressure, capillary refill time, central venous pressure, perfusion index, cardiac index, systemic vascular resistance, central venous oxygen saturation, and lactate clearance. The perfusion index range was 0.03 to 2.2 and ≤0.18 as the cut-off for mortality prediction providing 74% sensitivity and 78% specificity. The serum lactate concentration range was 0 to 16 mmol/L and >5.7 mmol/L as the cut-off for mortality prediction provided 70% sensitivity and 96% specificity at presentation to the emergency room. The lactate clearance range was 3% to 75% and >10% as the cut-off for survival prediction after resuscitation and at 6 h later. Perfusion index (PI), lactate, and lactate clearance provided comparable sensitivity and specificity for predicting outcomes among pediatric patients with shock Therefore, we suggest that the PI is an inexpensive, rapid, and non-invasive tool that can be used to predict illness severity and mortality in busy pediatric intensive care units and emergency departments. This tool may guide better patient triage and an earlier diagnosis of shock in this setting.

The ability of pulse oximetry-derived peripheral perfusion index to detect fluid responsiveness in patients with septic shock.

Fluid challenge test is a widely used method for the detection of fluid responsiveness in acute circulatory failure. However, detection of the patient's response to the fluid challenge requires monitoring of cardiac output which is not feasible in many settings. We investigated whether the changes in the pulse oximetry-derived peripheral perfusion index (PPI), as a non-invasive surrogate of cardiac output, can detect fluid responsiveness using the fluid challenge testor not. We prospectively enrolled 58 patients with septic shock on norepinephrine infusion. Fluid challenge test, using 200mL crystalloid solution, was performed in all study subjects. All patients received an additional 300mL crystalloid infusion to confirm fluid responsiveness. Velocity time integral (VTI) (using transthoracic echocardiography), and PPI were measured at the baseline, after 200mL fluid challenge, and after completion of 500mL crystalloids. Fluid responsiveness was defined by 10% increase in the VTI after completion of the 500mL. The predictive ability of ∆PPI [Calculated as (PPI after 200mL - baseline PPI)/baseline PPI] to detect fluid responders was obtained using the receiver operating characteristic curve. Forty-two patients (74%) were fluid responders; in whom, the mean arterial pressure, the central venous pressure, the VTI, and the PPI increased after fluid administration compared to the baseline values. ∆PPI showed moderate ability to detect fluid responders [area under receiver operating characteristic curve (95% confidence interval) 0.82 (0.70-0.91), sensitivity 76%, specificity 80%, positive predictive value 92%, negative predictive value 54%, cutoff value ≥ 5%]. There was a significant correlation between ∆PPI and ∆VTI induced by the fluid challenge. ∆PPI showed moderate ability to detect fluid responsiveness in patients with septic shock on norepinephrine infusion. Increased PPI after 200mL crystalloid challenge can detect fluid responsiveness with a positive predictive value of 92%; however, failure of the PPI to increase does not exclude fluid responsiveness. NCT03805321. Date of registration: 15 January 2019. Clinical trial registration URL: https://clinicaltrials.gov/ct2/show/NCT03805321?term=ahmed+hasanin&rank=9 .

Monitoring peripheral perfusion in sepsis associated acute kidney injury: Analysis of mortality.

Microcirculatory disorders have been consistently linked to the pathophysiology of sepsis. One of the major organs affected is the kidneys, resulting in sepsis-associated acute kidney injury (SA-AKI) that correlates considerably with mortality. However, the potential role of clinical assessment of peripheral perfusion as a possible tool for SA-AKI management has not been established. To address this gap, the purpose of this study was to investigate the prevalence of peripheral hypoperfusion in SA-AKI, its association with mortality, and fluid balance. This observational cohort study enrolled consecutive septic patients in the Intensive Care Unit. After fluid resuscitation, peripheral perfusion was evaluated using the capillary filling time (CRT) and peripheral perfusion index (PI) techniques. The AKI was defined based on both serum creatinine and urine output criteria. One hundred and forty-one patients were included, 28 (19%) in the non-SA-AKI group, and 113 (81%) in the SA-AKI group. The study revealed higher peripheral hypoperfusion rates in the SA-AKI group using the CRT (OR 3.6; 95% CI 1.35-9.55; p < 0.05). However, this result lost significance after multivariate adjustment. Perfusion abnormalities in the SA-AKI group diagnosed by both CRT (RR 1.96; 95% CI 1.25-3.08) and PI (RR 1.98; 95% CI 1.37-2.86) methods were associated to higher rates of 28-day mortality (p < 0.01). The PI's temporal analysis showed a high predictive value for death over the first 72 h (p < 0.01). A weak correlation between PI values and the fluid balance was found over the first 24 h (r = - 0.20; p < 0.05). In conclusion, peripheral perfusion was not different intrinsically between patients with or without SA-AKI. The presence of peripheral hypoperfusion in the SA-AKI group has appeared to be a prognostic marker for mortality. This evaluation maintained its predictive value over the first 72 hours. The fluid balance possibly negatively influences peripheral perfusion in the SA-AKI.

Continuous peripheral perfusion index in patients admitted to hospital wards - An observational study.

Risk patients admitted to hospital wards may quickly develop haemodynamic deterioration and early recognition has high priority to allow preventive intervention. The peripheral perfusion index (PPI) may be an indicator of circulatory distress by assessing peripheral perfusion non-invasively from photoplethysmography. We aimed to describe the characteristics of PPI in hospitalized patients since this is not well-studied. Patients admitted due to either acute exacerbation of chronic obstructive pulmonary disease (AECOPD) or after major abdominal cancer surgery were included in this study. Patients were monitored continuously up to 96hours with a pulse oximeter. Comparisons between median PPI each day, time of day and admission type were described with mean difference (MD) and were analysed using Wilcoxon rank sum test and related to morbidity and mortality. PPI data from 291 patients were recorded for a total of 9279hours. Median PPI fell from 1.4 (inter quartile range, IQR 0.9-2.3) on day 1 to 1.0 (IQR 0.6-1.6) on day 4. Significant differences occurred between PPI day vs evening (MD=0.18, 95% CI 0.16-0.20, P=.028), day vs night (MD=0.56, 95% CI 0.49-0.62, P<.0001) and evening vs night (MD=0.38, 95% CI 0.33-0.42, P=.002). No significant difference in median PPI between AECOPD and surgical patients was found (MD=0.15, 95% CI -0.08-0.38, P=.62). Lower PPI during daytime vs evening and night-time were seen for both populations. The highest frequency of serious adverse events and mortality was seen among patients with low median PPI. The clinical impact of PPI monitoring needs further confirmation.

Effect of mean arterial pressure change by norepinephrine on peripheral perfusion index in septic shock patients after early resuscitation.

BackgroundThe peripheral perfusion index (PI), as a real-time bedside indicator of peripheral tissue perfusion, may be useful for determining mean arterial pressure (MAP) after early resuscitation of septic shock patients. The aim of this study was to explore the response of PI to norepinephrine (NE)-induced changes in MAP.MethodsTwenty septic shock patients with pulse-induced contour cardiac output catheter, who had usual MAP under NE infusion after early resuscitation, were enrolled in this prospective, open-label study. Three MAP levels (usual MAP −10 mmHg, usual MAP, and usual MAP +10 mmHg) were obtained by NE titration, and the corresponding global hemodynamic parameters and PI were recorded. The general linear model with repeated measures was used for analysis of variance of related parameters at three MAP levels.ResultsWith increasing NE infusion, significant changes were found in MAP (F = 502.46, P < 0.001) and central venous pressure (F = 27.45, P < 0.001) during NE titration. However, there was not a significant and consistent change in continuous cardiac output (CO) (F = 0.41, P = 0.720) and PI (F = 0.73, P = 0.482) at different MAP levels. Of the 20 patients enrolled, seven reached the maximum PI value at usual MAP −10 mmHg, three reached the maximum PI value at usual MAP, and ten reached the maximum PI value at usual MAP +10 mmHg. The change in PI was not significantly correlated with the change in CO (r = 0.260, P = 0.269) from usual MAP −10 mmHg to usual MAP. There was also no significant correlation between the change in PI and change in CO (r = 0.084, P = 0.726) from usual MAP to usual MAP +10 mmHg.ConclusionsDiffering MAP levels by NE infusion induced diverse PI responses in septic shock patients, and these PI responses may be independent of the change in CO. PI may have potential applications for MAP optimization based on changes in peripheral tissue perfusion.

Observation on the efficacy of CT-guided lumbar sympathetic chemical destructive block in the treatment of cold sensation of limbs

Objective: To observe the clinical effects of CT-guided chemical destructive block of lumbar sympathetic nerve in the treatment of cold sensation of limbs. Methods: In this retrospective analysis, clinical data of 43 patients with cold sensation of limbs treated by lumbar sympathetic chemical destructive block in the Affiliated Hospital of Jiaxing University from January 2015 to January 2018 were collected. The changes of heart rate, non-invasive blood pressure (NIBP), oxygen saturation (SpO(2)), plantar temperature and peripheral perfusion index (PI) of patients were recorded and analyzed before treatment and 5 min after injection of anhydrous ethanol. The patients were followed up at postoperative 1 day, 1 week, 1 month, 3 months, 6 months, 1 year and 2 years. Results: Fourty-three patients underwent bilateral lumbar sympathetic nerve chemical destructive block under the CT-guided, and all patients were punctured to the target successfully. The PI of patients before and after treatment were 1.2±0.6, 7.2±3.0 respectively, which was significantly increased after treatment compared with before treatment, and the difference was statistically significant (t=12.386, P<0.05). The plantar temperature of patients before and after treatment respectively were (29.6±1.7)℃, (34.6±1.1)℃, which was significantly increased after treatment compared with before treatment, and the difference was statistically significant (t=15.057, P<0.05). There were no significant differences in heart rate, NIBP and SpO(2) between before and after treatment (all P>0.05). Lumbar sympathetic chemical destructive block was clinically effective in 39 patients (90.7%) and ineffective in 4 patients (9.3%). Among the 39 clinically effective patients, the curative effects were excellent in 29 cases and improved in 10 cases. Postoperative recurrence occurred in 10 cases (25.6%). The satisfaction rates of patients at 1 day, 1 week, 1 month, 3 months, 6 months, 1 year and 2 years after operation were 93.0%, 90.7%, 86.0%, 76.7%, 69.7%, 65.1% and 53.4%, respectively. Conclusion: Lumbar sympathetic chemical destructive block is a safe and effective way for the treatment of cold sensation of limbs, which can improve the symptoms of cold sensation of limbs to some extent.

The role of peripheral perfusion index in differential diagnosis of cardiac and pulmonary-origin dyspnea in emergency service

Introduction:Pulmonary and cardiac disorders are diagnosed in most patients presenting to the emergency department with dyspnea. Discrimination of pulmonary and cardiac pathologies from each other and early intervention have vital importance. Various methods have been used for assessment of peripheral perfusion, and the peripheral perfusion index) has gained popularity in recent years. This study aimed to investigate the contribution of peripheral perfusion index to the evaluation process in patients presenting with the complaint of dyspnea and diagnosed with either a pulmonary or cardiac pathology.Materials and Methods:We retrospectively reviewed the charts of patients who presented to emergency department with dyspnea between 1 July 2018 and 1 July 2019. Patients in whom the cause of dsypnea was determined to be a cardiac or pulmonary pathology were included in the study. The age, gender, peripheral perfusion index value at admission, the diagnosis, and the hospitalization status were recorded.Results:One hundred and ninety patients consisting of 106 (55.8%) males and 84 (44.2%) females were included in our study. While a pulmonary pathology was determined in 141 (74.2%) patients and a cardiac pathology in 49 (25.8%) patients, 72 (37.9%) patients were decided to be hospitalized. No difference was determined between patients with pulmonary and cardiac pathologies regarding peripheral perfusion index. When the patients were compared regarding hospitalization status and discharge from the emergency department, no significant difference was found to be present between the groups.Conclusion:Since peripheral perfusion index is a noninvasive, easy-to-perform, rapid, and reproducible test, it has been promising as a prognostic and diagnostic parameter. However, it has been realized that PPI was unsuccessful in the evaluation of patients with dyspnea, in the differential diagnosis of cardiac and pulmonary pathologies and prediction of hospitalization status in the emergency department.

Post-ROSC peripheral perfusion index discriminates 30-day survival after out-of-hospital cardiac arrest.

Prognostication after an out-of-hospital cardiac arrest (OHCA) remains a challenge. The peripheral-derived perfusion index (PI) is a simple and non-invasive way to assess perfusion. We sought to assess whether the PI was able to discriminate the prognosis of patients resuscitated from an OHCA. All the reports generated by the manual monitor/defibrillator (Corpuls 3 by GS Elektromedizinische Geräte G. Stemple GmbH, Germany) used for all the OHCAs who achieved ROSC treated by our Emergency Medical Service from January 2015 to December 2018 were reviewed. The mean PI value of each minute after ROSC was automatically provided by the device and the mean value of 30min of monitoring (MPI30) was calculated. Pre-hospital data were collected according to the Utstein 2014 recommendations. Among 1,909 resuscitation attempts, ROSC was achieved in 346 and it was possible to calculate an MPI30 in 164. MPI30 was higher in the patients who survived at 30days [1.6 (95% CI 1.2-2.1) vs 1 (95% CI 0.8-1.3), p = 0.0017]. At the multivariable Cox regression model, after correction for shockable rhythm, witnessed status, bystander CPR, age, and blood pressure, MPI30 was found to be an independent predictor of both 30-day mortality [RR 0.83 (95% CI 0.69-0.99), p = 0.036] and 30-day mortality or poor neurologic outcome [RR 0.85 (95% CI 0.72-0.99), p = 0.04]. Overall 30-day survival with good neurologic outcome was significantly different in the three tertiles [T1: 0.1-0.8; T2: 0.9-1.8 and T3: 1.82-7.8, log-rank p = 0.007]. The post-ROSC peripheral perfusion index was found to be an independent predictor of 30-day mortality or poor neurologic outcome. It could help prognostication in OHCA patients.

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

IntroductionPeripheral 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). MethodsThis 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. ResultsA 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. ConclusionPeripheral 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.

COVID-19: Pulse oximeters in the spotlight

From home to intensive care units, innovations in pulse oximetry are susceptible to improve the monitoring and management of patients developing acute respiratory failure, and particularly those with the coronavirus disease 2019 (COVID-19). They include self-monitoring of oxygen saturation (SpO2) from home, continuous wireless SpO2 monitoring on hospital wards, and the integration of SpO2 as the input variable for closed-loop oxygen administration systems. The analysis of the pulse oximetry waveform may help to quantify respiratory efforts and prevent intubation delays. Tracking changes in the peripheral perfusion index during a preload-modifying maneuver may be useful to predict preload responsiveness and rationalize fluid therapy.

Peripheral perfusion index predicting prolonged ICU stay earlier and better than lactate in surgical patients: an observational study

BackgroundPeripheral perfusion index (PPI) is an indicator reflecting perfusion. Patients undergoing long time surgeries are more prone to hypoperfusion and increased lactate. Few studies focusing on investigating the association between PPI and surgical patients’ prognoses. We performed this study to find it out.MethodsFrom January 2019 to September 2019, we retrospected all surgical patients who were transferred to ICU, Xinyang Central hospital, Henan province, China. Inclusive criteria: age ≥ 18 years old; surgical length ≥ 120 min. Exclusive criteria: died in ICU; discharging against medical advice; existing diseases affecting blood flow of upper limbs, for example, vascular thrombus in arms; severe liver dysfunction.We defined “prolonged ICU stay” as patients with their length of ICU stay longer than 48 h. According to the definition, patients were divided into two groups: “prolonged group” (PG) and “non-prolong group” (nPG). Baseline characteristics, surgical and therapeutic information, ICU LOS, SOFA and APACHE II were collected. Besides we gathered data of following parameters at 3 time points (T0: ICU admission; T1: 6 h after admission; T2: 12 h after admission): mean artery pressure (MAP), lactate, heart rate (HR), PPI and body temperature. Data were compared between the 2 groups. Multivariable binary logistic regression and ROC (receiver operating characteristic) curves were performed to find the association between perfusion indictors and ICU LOS.ResultsEventually, 168 patients were included, 65 in PG and 103 in nPG. Compared to nPG, patients in PG had higher blood lactate and lower PPI. PPI showed significant difference between two groups earlier than lactate (T0 vs T1). The value of PPI at two time points was lower in PG than nPG(T0: 1.09 ± 0.33 vs 1.41 ± 0.45, p = 0.001; T1: 1.08 ± 0.37 vs 1.49 ± 0.41, p < 0.001).Increased lactateT1(OR 3.216; 95% CI 1.253–8.254, P = 0.015) and decreased PPIT1 (OR 0.070; 95% CI 0.016–0.307, P < 0.001) were independently associated with prolonged ICU stay. The area under ROC of the PPIT1 for predicting ICU stay> 48 h was 0.772, and the cutoff value for PPIT1 was 1.35, with 83.3% sensitivity and 73.8% specificity.ConclusionsPPI and blood lactate at T1(6 h after ICU admission) are associated with ICU LOS in surgical patient. Compared to lactate, PPI indicates hypoperfusion earlier and more accurate in predicting prolonged ICU stay.

Oxygen saturation and perfusion index screening in neonates at high altitudes: can PDA be predicted?

Screening critical congenital heart disease in neonates with 24-48 h of age could be made by oxygen saturation determination. Perfusion index may be used as an adjunct to pulse oximetry screening to detect non-cyanotic critical congenital heart disease cases such as a left heart outflow obstruction. We evaluate the results of combined screening for oxygen saturation and peripheral perfusion index at high altitudes. The study included 501 neonates older than gestational week 35. The mean oxygen saturation was lower than at sea level, and the screening test was positive in a total of 21 (4.2%) babies. Critical congenital heart diseases were not detected in any patient. A total of 10 (2%) babies were detected with PDA, nine (1.8%) of whom recorded a positive screening test. The prevalence of PDA was significantly higher in the positive screening test group when compared with those who underwent echocardiography due to clinical findings.Conclusion: The median peripheral perfusion index at high altitude was not lower than at sea level, while the mean oxygen saturation, in contrast, was lower than at sea level. The low partial oxygen pressure found at high altitudes leads to a variation in postnatal adaptation and an increased prevalence of PDA. Accordingly, oxygen saturation screening may serve to identify babies with PDA at high altitudes. What is Known: • Oxygen saturation is known to be low at high altitudes, and thus the rates of false positivity are high when screening for critical congenital heart disease. • High altitudes are also associated with an increased prevalence of simple congenital heart disease. What is New: • The peripheral perfusion index at high altitude is not lower than at sea level. • The prevalence of PDA is significantly higher in those with false positive screening results.

Effects of nitroglycerin versus labetalol on peripheral perfusion during deliberate hypotension for sinus endoscopic surgery: a randomized, controlled, double-blinded trial

BackgroundDeliberate hypotension is used to provide a bloodless field during functional endoscopic sinus surgery; however, the impact of controlled hypotension during anesthesia on peripheral tissue perfusion has not been extensively evaluated. The aim of this study was to compare the impact of nitroglycerin- versus labetalol-induced hypotension on peripheral perfusion.MethodsThe present randomized, double-blinded, controlled trial included adult patients undergoing endoscopic sinus surgery. Patients were allocated to one of two groups according to the drug received for induction of deliberate hypotension: nitroglycerin (n = 20) or labetalol (n = 20). Mean arterial pressure was maintained at 55–65 mmHg in both groups. Both study groups were compared according to pulse oximeter-derived peripheral perfusion index (primary outcome), serum lactate level, mean arterial pressure, heart rate, surgical field score, and intraoperative blood loss.ResultsForty patients were included in the final analysis. The nitroglycerin group exhibited a higher peripheral perfusion index at nearly all records (p < 0.0001) and lower postoperative serum lactate levels (1.3 ± 0.2 mmol/L vs. 1.7 ± 0.4 mmol/L; p = 0.001) than the labetalol group. The peripheral perfusion index was higher in the nitroglycerin group than at baseline at most intraoperative readings. The median surgical field score was modestly lower in the labetalol group than in the nitroglycerin group in the first 20 min (2 [interquartile range (IQR) 2–2.5] versus 1.5 [IQR 1–2]; p = 0.001). Both groups demonstrated comparable and acceptable surgical field scores in all subsequent readings.ConclusionNitroglycerin-induced deliberate hypotension was accompanied by higher peripheral perfusion index and lower serum lactate levels than labetalol-induced deliberate hypotension during sinus endoscopic surgery.Trial registrationThe study was registered at clinicaltrials registry system with trial number: NCT03809065. Registered at 19 January 2019. This study adheres to CONSORT guidelines.

Alterations in Skin Blood Flow at the Fingertip Are Related to Mortality in Patients With Circulatory Shock.

Skin blood flow is rapidly altered during circulatory shock and may remain altered despite apparent systemic hemodynamic stabilization. We evaluated whether changes in skin blood flow during circulatory shock were related to survival. Prospective study. Thirty-five-bed medical-surgical university hospital department of intensive care. Twenty healthy volunteers and 70 patients with circulatory shock (< 12 hr duration), defined as the need for vasopressors to maintain mean arterial pressure greater than or equal to 65 mm Hg and signs of altered tissue perfusion. We assessed skin blood flow using skin laser Doppler on the fingertip for 3 minutes at basal temperature (SBFBT) and at 37°C (SBF37) (thermal challenge test) once in volunteers and at the time of inclusion and after 6, 24, 48, 72, and 96 hours in patients with shock. Capillary refill time and peripheral perfusion index were measured at the same time points on the contralateral hand. The thermal challenge response (ΔSBF/ΔT) was calculated using the following formula: (SBF37-SBFBT)/(37-basal temperature). Area under the receiver operating characteristic curves were calculated to evaluate variables predictive of ICU mortality. At inclusion, skin blood flow and ΔSBF/ΔT were lower in patients than in volunteers. Baseline skin blood flow (31 [17-113] vs 16 [9-32] arbitrary perfusion units; p = 0.01) and ΔSBF/ΔT (4.3 [1.7-10.9] vs 0.9 [0.4-2.9] arbitrary perfusion unit/s) were greater in survivors than in nonsurvivors. Capillary refill time was shorter in survivors than in nonsurvivors; peripheral perfusion index was similar in the two groups. ΔSBF/ΔT (area under the receiver operating characteristic curve 0.94 [0.88-0.99]) and SBFBT (area under the receiver operating characteristic curve 0.83 [0.73-0.93]) had the best predictive value for ICU mortality with cutoff values less than or equal to 1.25 arbitrary perfusion unit/°C (sensitivity 88%, specificity 89%) and less than or equal to 21 arbitrary perfusion unit (sensitivity 84%, specificity 81%), respectively. Alterations in fingertip skin blood flow can be evaluated using a laser Doppler thermal challenge technique in patients with circulatory shock and are directly related to outcome. These novel monitoring techniques could potentially be used to guide resuscitation.

Peripheral perfusion index percentiles for healthy newborns by gestational age and sex in China

Peripheral perfusion index (PPI) percentiles for newborns serve as an important observation tool in clinical practice, but research pertaining to reference ranges are lacking. The aim of this study was to establish PPI percentiles for healthy newborns by gestational age and sex at 24–48 hours of life. We conducted an observational study and examined PPI values at 24–48 hours of life in 3814 asymptomatic newborns born between 35 and 41 weeks gestation who did not need medical treatment from June 1, 2016 to May 31, 2017 at two maternity hospitals in Shanghai. Linear regression analysis was carried out on the associations between PPI values and variables such as gestational age, sex, and birthweight. Pre-ductal PPI values linearly increased with gestational age (β: 0.072; 95% CI: 0.037, 0.107; P = 0.000). Post-ductal PPI values were also mainly related to gestational age (β: 0.051; 95% CI: 0.018, 0.085; P = 0.003). Smoothed reference curves for pre- and post-ductal PPI values by gestational age and sex were derived from LMS Chart Maker. Our study is the first study to establish PPI percentiles curves for healthy newborns by gestational age and sex at 24–48 hours of life. Further research is required for the implementation of PPI curves into clinical practice.