Immediate complications and risk factors following radial arterial catheterisation in paediatric patients at a tertiary centre.

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.

BackgroundTracking preload dependency non-invasively to maintain adequate tissue perfusion in the perioperative period can be challenging.The effect of phenylephrine on stroke volume is dependent upon preload. Changes in stroke volume induced by phenylephrine administration can be used to predict preload dependency. The change in the peripheral perfusion index derived from photoplethysmography signals reportedly corresponds with changes in stroke volume in situations such as body position changes in the operating room. Thus, the peripheral perfusion index can be used as a non-invasive potential alternative to stroke volume to predict preload dependency. Herein, we aimed to determine whether changes in perfusion index induced by the administration of phenylephrine could be used to predict preload dependency.MethodsWe conducted a prospective single-centre observational study. The haemodynamic parameters and perfusion index were recorded before and 1 and 2 min after administering 0.1 mg of phenylephrine during post-induction hypotension in patients scheduled to undergo surgery. Preload dependency was defined as a stroke volume variation of ≥ 12% before phenylephrine administration at a mean arterial pressure of < 65 mmHg. Patients were divided into four groups according to total peripheral resistance and preload dependency.ResultsForty-two patients were included in this study. The stroke volume in patients with preload dependency (n = 23) increased after phenylephrine administration. However, phenylephrine administration did not impact the stroke volume in patients without preload dependency (n = 19). The perfusion index decreased regardless of preload dependency. The changes in the perfusion index after phenylephrine administration exhibited low accuracy for predicting preload dependency. Based on subgroup analysis, patients with high total peripheral resistance tended to exhibit increased stroke volume following phenylephrine administration, which was particularly prominent in patients with high total peripheral resistance and preload dependency.ConclusionThe findings of the current study revealed that changes in the perfusion index induced by administering 0.1 mg of phenylephrine could not predict preload dependency. This may be attributed to the different phenylephrine-induced stroke volume patterns observed in patients according to the degree of total peripheral resistance and preload dependency.Trial registrationUniversity Hospital Medical Information Network (UMIN000049994 on 9/01/2023).

Direct Versus Guidewire-Assisted Pediatric Radial Artery Cannulation Technique

To investigate the prognostic value of the peripheral perfusion index (PPI) in patients with septic shock. This prospective cohort study, conducted at the emergency intensive care unit of Peking University People's Hospital, recruited 200 patients with septic shock between January 2023 and August 2023. These patients were divided into survival (n=84) and death (n=116) groups based on 28-day outcomes. Clinical evaluations included laboratory tests and clinical scores, with lactate and PPI values assessed upon admission to the emergency room and at 6 h and 12 h after admission. Risk factors associated with mortality were analyzed using univariate and multivariate Cox regression analyses. Receiver operator characteristic (ROC) curve was used to assess predictive performance. Mortality rates were compared, and Kaplan-Meier survival plots were created. Compared to the survival group, patients in the death group were older and had more severe liver damage and coagulation dysfunction, necessitating higher norepinephrine doses and increased fluid replacement. Higher lactate levels and lower PPI levels at 0 h, 6 h, and 12 h were observed in the death group. Multivariate Cox regression identified prolonged prothrombin time (PT), decreased 6-h PPI and 12-h PPI as independent risk factors for death. The area under the curves for 6-h PPI and 12-h PPI were 0.802 (95% CI 0.742-0.863, P<0.001) and 0.945 (95% CI 0.915-0.974, P<0.001), respectively, which were superior to Glasgow Coma Scale (GCS), Sequential Organ Failure Assessment (SOFA) scores (0.864 and 0.928). Cumulative mortality in the low PPI groups at 6 h and 12 h was significantly higher than in the high PPI groups (6-h PPI: 77.52% vs. 22.54%; 12-h PPI: 92.04% vs. 13.79%, P<0.001). PPI may have value in predicting 28-day mortality in patients with septic shock.

To investigate the efficacy of the perfusion index in assessing block success in pediatric patients undergoing elective supracondylar fracture repair surgery. It was a retrospective study in a tertiary-care center. Twenty-eight pediatric supracondylar humerus fracture patients who underwent elective surgery for fracture repair were evaluated. Perfusion index, pulse rate, pleth variability index (PVi), and oxygen saturation were measured at different time intervals before and after the coracoid infraclavicular block procedure. The changes in perfusion index (PI) values were found to be statistically significant (p˂0.05). The Bonferroni analysis revealed that the results obtained at three separate measurement times differed significantly (p˂0.05). On the other hand, changes in other variables were not statistically significant (p˃0.05). The perfusion index can be used as an indicator of block success in elective surgeries of the upper extremities in pediatric patients.

Changes in stroke volume (deltaSV) induced by a lung recruitment manoeuvre (LRM) have been shown to accurately predict fluid responsiveness during protective mechanical ventilation. Cardiac output monitors are used in a limited number of surgical patients. In contrast, all patients are monitored with a pulse oximeter, that may enable the continuous monitoring of a peripheral perfusion index (PI). We postulated that changes in PI (deltaPI) may reflect deltaSV during brief modifications of cardiac preload. We studied 47 patients undergoing neurosurgery and ventilated with a tidal volume of 6-8 ml/kg. All patients were monitored with a pulse contour system enabling the continuous monitoring of SV and with a pulse oximeter enabling the continuous monitoring of PI. LRMs were performed by increasing airway pressure up to 30 cmH20 for 30 s. Fluid loads (250 ml of saline 0.9% in 10 min) were performed only in patients who experienced a deltaSV > 30% during LRMs (potential fluid responders). LRMs induced a 26% decrease in SV (p < 0.05) and a 27% decrease in PI (p < 0.05). We observed a fair relationship between deltaPI and deltaSV (r2 = 0.34). A deltaPI ≥ 26% predicted a deltaSV > 30% with a sensitivity of 83% and a specificity of 78% (AUC = 0.84,95%CI 0.71-0.93). 24 patients experienced a deltaSV > 30% and subsequently received fluid. Fluid loads induced a 16% increase in SV and a 17% increase in PI, but fluid-induced deltaPI and deltaSV were weakly correlated (r2 = 0.19). In neurosurgical patients, we conclude that deltaPI may be used as a surrogate for deltaSV during LRMs but not during fluid loading.

Background & objectivesFollowing surgical treatment and subsequent immobilisation of one limb, physiological reductions in blood flow are expected due to limited or no movement. This study was designed to investigate the change in perfusion index in a resting limb when the contralateral limb exercises (active and passive). MethodsThis was a two-arm comparative study with 39 healthy participants (22 males, 17 females) with a mean (SD) age of 23.4 (5.2) years. One limb was set to exercise (active and passive in different sessions), and another limb rested with a pre-designed exercise protocol. We measured perfusion index in exercising and non-exercising limbs after 3, 4, 5, and 6 min of exercise. ResultsIn resting upper limbs, there was an increase in the perfusion index during both active and passive exercise of the contralateral limb (achieved at 3 min in active and 4 min in passive exercise). In resting lower limbs, in active exercise, the increase in perfusion index occurred at 4 min and 6 min of exercise. In passive exercise, there was no significant change in perfusion index. Interpretation & conclusionsActive exercise of one limb significantly increases blood flow in the opposite, resting limb. This effect is not found in passive exercise in the lower limb. Hence, when one limb undergoes surgery, for a higher perfusion on that limb, an active exercise or passive exercise in the upper limb, or active exercise in the lower limb may be beneficial.

Gangrene of digits associated with radial artery cannulation

IntroductionWe investigated whether combining the peripheral perfusion index (PI) and central venous oxygen saturation(ScvO2) would identify subsets of patients for assessing the tissue perfusion and predicting outcome during the resuscitation in critically ill patients.MethodsA total of 202 patients with central venous catheters for resuscitation were enrolled in this prospective observational study. The arterial, central venous blood gas and the PI were measured simultaneously at the enrollment (T0) and 8 h (T8) after early resuscitation. Based on the distribution of the PI in healthy population, a cutoff of PI ≥1.4 was defined as a normal PI. Moreover, the critical value of PI was defined as the best cutoff value related to the mortality in the study population. The PI impairment stratification is defined as follows: a normal PI(≥1.4), mild PI impairment (critical value < PI < 1.4) and critical PI impairment (PI ≤ critical value).ResultsThe PI at T8 was with the greatest AUC for prediction the 30-day mortality and PI is an independent risk factor for 30-day mortality. Moreover, a cutoff of PI < 0.6 is related to poor outcomes following resuscitation. So, based on cutoffs of ScvO2 (70 %) and critical PI (0.6) at T8, we assigned the patients to four categories: group 1 (PI ≤ 0.6 on ScvO2 < 70 %), group 2 (PI ≤ 0.6 on ScvO2 ≥ 70 %), group 3 (PI > 0.6 on ScvO2 < 70 %), and group 4 (PI > 0.6 on ScvO2 ≥ 70 %). The combination of low ScvO2(<70 %) and PI(≤0.6) was associated with the lowest survival rates at 30 days [log rank (Mantel–Cox) = 87.518, p < 0.0001]. The sub-group patients who had high ScvO2(>80 %) at T8 were with low mortality and high PI. Moreover, the normal PI (≥1.4) did not show a better outcome than mild impaired PI (0.6-1.4) patients who had a normalized ScvO2(>70 %) after resuscitation. The PI was correlated with the lactate, P(v-a)CO2, and ScvO2 in all the measurements (n = 404). These relationships are strengthened with abnormal PI (PI < 1.4) but not with normal PI (PI ≥ 1.4).ConclusionComplementing ScvO2 assessment with PI can better identify endpoints of resuscitation and adverse outcomes. Pursuing a normalized PI (≥1.4) may not result in better outcomes for a mild impaired PI after ScvO2 is normalized.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-015-1057-8) contains supplementary material, which is available to authorized users.

To detect occurrence of clinical shock and impending shock by monitoring Peripheral Perfusion Index (PI). In this study, 100 children aged 1 mo to 12 y of age who needed hemodynamic monitoring were included and categorized into five age groups. Demographic data, nutritional status, vital parameters, perfusion index and laboratory parameters were recorded. Hemodynamic monitoring was done for 48h. In total, 65 and 35 children were admitted with and without features of shock respectively. Nine hundred thirty six hemodynamic measurements were taken and analyzed. Correlation between perfusion index, blood pressures and clinically assessed shock were done. Clinical shock can be reasonably detected when perfusion index value is less than 1.15 in children less than 3 y of age, less than 1.25 in 3 to 10 y of age and less than 1.55 in 10 to 12 y of age. These values had high sensitivity and low false positivity in detecting clinically assessed shock in that particular age group. PI had good correlation with pulse pressure and systolic blood pressure in all age groups and weak correlation with mean arterial blood pressure and diastolic blood pressure. A 57% reduction in PI value from the baseline value may predict impending shock in children. Perfusion index can be used as a non-invasive, continuous parameter to monitor peripheral perfusion in children and to detect impending shock.

During cardiopulmonary resuscitation (CPR), some parameters (e.g., intraarterial pressure measurement and end-tidal carbon dioxide (EtCO2)) indicate the quality andoutcome of resuscitation. These parameters are generally based on monitoring the hemodynamic status. Perfusion index (PI) is a calculation from the photoplethysmography (PPG) signal and displays the proportion of pulsatile to non-pulsatile light absorption or reflection in the PPG signal. It helps to evaluate cardiac output and tissue perfusion in the care of a critical patient. Its most important advantages are that it can be easily measured with a pulse oximeter probe attached to the finger (non-invasive), can be objectively repeated, can be applied quickly, and is inexpensive. Normal PI values range from 0.2% to 20%. Despite being recognized as a valuable indicator of hemodynamics, there is limited information regarding its relevance in patients experiencing cardiac arrest. Although the PI is known to be a valuable parameter to indicate hemodynamics, information about its value in cardiac arrest patients is limited. This study aims to evaluate the performance of PI and EtCO2 in predicting the return of spontaneous circulation (ROSC) among cardiac arrest patients. This was a single-center, prospective, observational clinical study including both out-of-hospital and in-hospital adult cardiac arrest patients. The study was conducted from November 1, 2018 to April 30, 2019 at the Emergency Department (ED) of the Hacettepe University Hospital, Ankara, Turkey. The EtCO2 values of the patients were recorded at the time they were intubated (t0) and every five minutes (t5, t10, t15...) during CPR. Along with these measurements, PI values were measured with the Masimo Signal Extraction Technology device (Masimo, California, United States). The study's primary outcome was PI's performance in predicting the ROSC among cardiac arrest patients. The secondary outcomes of the study were the performance of EtCO2 in predicting the ROSC among cardiac arrest patients and the association between PI and EtCO2 values. We included a total of 100 cases. The mean age of patients was 70.4 ± 13.4 years, and 65% were male. The ROSC was achieved in 29patients. There was no statistical difference in PI values between the ROSC (+) and ROSC (-) groups at any minute. However, in the ROSC (+) group, EtCO2 values were observed to be high starting from the fifth minute (t5, p=0.010; t10, p<0.001; t15, p=0.014; t20, p=0.033; t25, p=0.003, respectively). There was no correlation between the PI and EtCO2 values at 0, 5, 10, 15, 20, and 25 minutes (t0, p=0.436; t5, p=0.154; t10, p=0.557; t15, p=0.740; t20 p=0.241; t25 p=0.201, respectively). Measuring PI values during resuscitation in intubated cardiac arrest patients does not help clinicians predict the outcome. In addition, no correlation was found with EtCO2 values. However, EtCO2 values remained high in patients with the ROSC from the fifth minute onward. Further larger-scale studies are needed regarding the optimal use of PI in cardiac arrest patients.

The use of ultrasound guidance for supraclavicular brachial plexus blocks (SCB) enhances the precision and success of nerve blocks by improving visualization. Despite this, methods to assess block success, such as pin-prick tests, remain subjective. The perfusion index (PI), which measures blood flow changes, has emerged as an objective and noninvasive indicator of block efficacy. This study aims to evaluate PI and PI ratio (PIR) as predictors of successful SCB and establish cutoff values for PI to determine block success. A prospective, observational study was conducted with 40 patients scheduled for upper limb surgeries. PI was measured using pulse oximeters at baseline and intervals after the block. The primary outcome was to establish cutoff values of PI and PIR at 10 min to predict block success, and secondary outcomes included comparing PI values between successful and failed blocks. PI increased significantly in the blocked arm compared to the unblocked arm, with a statistically significant difference from the 6-min mark onward. A PI value >6.10 and a PIR >3.90 at 10 min were 90.9% sensitive and 100% specific in predicting block success. Receiver-operator characteristic analysis confirmed the discriminative utility of PI and PIR. PI and PIR are effective noninvasive predictors of SCB success, with specific cutoff values offering high sensitivity and specificity for determining block efficacy. Further studies are needed to validate these findings in patients with conditions that may affect PI values.

Does Radial Artery Cannulation Affect the Perfusion of the Dominant Hand in Adult Patients with Normal Modified Allen's Test Undergoing Cardiac Surgeries? Data Derived from the Peripheral Perfusion Index

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.

Introduction Pulse oximetry screening is a safe, feasible test, effective in identifying congenital heart diseases in otherwise well-appearing newborns. Uncertainties still persist on the most effective algorithm to be used and the timing of screening. The aim of this study was to evaluate the role of the pulse oximetry screening associated with the peripheral perfusion index performed in the first 24 hours of life for the early detection of congenital heart diseases and noncongenital heart diseases in the newborns. Materials and Methods A prospective observational cohort study was conducted. The enrollment criteria were as follows: term newborns with an APGAR score >8 at 5 minutes. The exclusion criteria were as follows: clinical signs of prenatal/perinatal asphyxia or known congenital malformations. Four parameters of pulse oximetry screening were utilized: saturation less than 90% (screening 1), saturation of less than 95% in one or both limbs (screening 2), difference of more than 3% between the limbs (screening 3), and preductal peripheral perfusion index or postductal peripheral perfusion index below 0.70 (screening 4). The likelihood ratio, sensibility, specificity, and positive and negative predictive values for identification of congenital heart diseases or noncongenital heart diseases (suspicion of perinatal infection and any respiratory diseases) were evaluated. Results The best predictive results for minor congenital heart disease were obtained combining screening 3 and screening 4 (χ2 (1) = 15,279; p < 0.05; OR = 57,900 (9,465–354,180)). Screening 2, screening 3, and screening 4 were predictive for noncongenital heart diseases (χ2 (1) = 11,550; p < 0.05; OR = 65,744 (10,413–415,097)). Combined screenings 2–4 were predictive for both congenital heart disease and noncongenital heart disease (χ2 (1) = 22,155; p < 0.05; OR = 117,685 (12,972–1067,648)). Conclusions Combining peripheral saturation with the peripheral perfusion index in the first 24 hours of life shows a predictive role in the detection of minor congenital heart diseases and neonatal clinical conditions whose care needs attention.