Plethysmographic Variability Index Research Articles

Clinical utility of ultrasonography, pulse oximetry and arterial line derived hemodynamic parameters for predicting post-induction hypotension in patients undergoing elective craniotomy for excision of brain tumors - A prospective observational study

BackgroundHypotension, which is a common adverse effect of induction of anesthesia, may be especially detrimental in neurosurgical patients. Hence, it is important to investigate hemodynamic parameters which may be useful in identifying patients at risk of hypotension, following induction. Our study was designed to assess the utility of parameters derived from ultrasonography, pulse oximeter and arterial line for predicting post-induction hypotension. MethodsThe study was designed as a prospective, observational trial. Written informed consent was obtained from 100 American Society of Anesthesiologists (ASA) 1 and 2 patients, between 18-60 years of age, scheduled for elective craniotomy for brain tumors. Arterial cannula was inserted before induction of anesthesia and connected to Vigileo cardiac output monitor. Baseline stroke volume variation (SVV), stroke volume (SV), cardiac index (Ci), cardiac output (CO) and pulse pressure variation (PPV) were recorded. Plethysmography variability index (PVI) and perfusion index (PI) were obtained from the Masimo rainbow SET® Radical-7® pulse oximeter. Ultrasonographic assessment of the inferior vena cava (IVC) was performed before induction of anesthesia and again within 15 min after induction. Maximum and minimum IVC diameters (dIVCmax and dIVCmin) and collapsibility index (CI) were measured. All the other aforementioned parameters were recorded every minute starting at induction, until the 15th minute following induction. ResultsPI, CI and dIVCmax were found to have the largest AUCROC for the prediction of post-induction hypotension (AUCROC 0.852, 0.823 and 0.781 respectively). Multiple logistic regression analysis revealed CI to be the most significant independent factor for the prediction of post-induction hypotension. ConclusionNon-invasively derived hemodynamic parameters like dIVCmax, CI and PI were more accurate for the prediction of post-induction hypotension, compared to invasively derived parameters.

Dynamic parameters for fluid responsiveness in mechanically ventilated children: A systematic review.

Fluid administration is the initial step of treatment of unstable pediatric patients. Evaluation of fluid responsiveness is crucial in mechanically ventilated children to avoid fluid overload, which increases mortality. We aim to review and compare the diagnostic performance of dynamically hemodynamic parameters for predicting fluid responsiveness in mechanically ventilated children. A systematic review was performed using four electronic databases, including PubMed, EMBASE, Scopus, and Central, for published articles from 1 January 2010 to 31 December 2020. Studies were included if they described diagnostic performance of dynamic parameters after fluid challenge was performed in mechanically ventilated children. Pediatric intensive and cardiac intensive care unit, and operative room. Children aged 1 month to 18 years old who were under mechanical ventilation and required an intravenous fluid challenge. Twenty-seven studies were included in the systematic review, which included 1,005 participants and 1,138 fluid challenges. Respiratory variation in aortic peak velocity was reliable among dynamic parameters for predicting fluid responsiveness in mechanically ventilated children. All studies of respiratory variation in aortic peak velocity showed that the area under the receiver operating characteristic curve ranged from 0.71 to 1.00, and the cutoff value for determining fluid responsiveness ranged from 7% to 20%. Dynamic parameters based on arterial blood pressure (pulse pressure variation and stroke volume variation) were also used in children undergoing congenital heart surgery. The plethysmography variability index was used in children undergoing neurological and general surgery, including the pediatric intensive care patients. The respiratory variation in aortic peak velocity exhibited a promising diagnostic performance across all populations in predicting fluid responsiveness in mechanically ventilated children. High sensitivity is advantageous in non-cardiac surgical patients and the pediatric intensive care unit because early fluid resuscitation improves survival in these patients. Furthermore, high specificity is beneficial in congenital heart surgery because fluid overload is particularly detrimental in this group of patients. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=206400.

Comparative efficacy of finger versus forehead Plethysmographic Variability Index monitoring in pediatric surgical patients.

The Plethysmographic Variability Index can be measured by both finger and forehead probes. Vasoconstriction may jeopardize the reliability of finger PVI measurements in pediatric patients undergoing surgery. However, forehead vasculature exhibits more marked resistance to alterations in the vasomotor tonus. Our aim was to compare the Plethysmographic Variability Index measured via finger or forehead probes in mechanically ventilated pediatric surgery patients in terms of their ability to predict fluid responsiveness as well as to determine the best cut-off values for these two measurements. A total of 50 pediatric patients undergoing minor elective surgery were included after provision of parental consent and ethics committee approval. Perfusion index measured at the finger or forehead and Plethysmographic Variability Index monitoring comprised the primary assessments. Hemodynamic parameters monitored included perfusion index, Plethysmographic Variability Index, and cardiac output. A ≥ 15% increase in cardiac output following passive leg raise maneuver was considered to show fluid responsiveness. Two groups were defined based on fluid responsiveness: Group R (responsive) and Group NR (non-responsive). Student's t-test, Mann-Whitney U test, DeLong test, and ROC were used for statistical analysis. The area under curve for finger and forehead Plethysmographic Variability Index prior to passive leg raise maneuver were 0.699 (p=.011) and 0.847 (p < .001), respectively. The sensitivity for finger and forehead measurements at a cut-off value of ≤14% was 92.9% and 96.4%, and 45.4% and 72.7%, respectively. Although forehead and finger Plethysmographic Variability Index monitoring were similarly sensitive in predicting fluid responsiveness in pediatric surgical patients, the former method provided higher specificity. The best cut-off value for PVI measurements with forehead and finger probes was found to be 14%.

Relation between preoperative fasting time and the plestimographic variability index (PVI)

Preoperative fasting can also lead to physiological deleterious effects such as dehydration, and hypovolemia. The Plethysmographic Variability Index (PVI, Masimo Corp, Irvine, CA, USA), is a dynamic measurement and its variability could be related to hydration status. Objective: Find a correlation between the number of hours of preoperative fasting and the measurements of PVI. Studio and design: Experimental, prospective, longitudinal. Material and methods: During one-year, patients ASA I scheduled for elective general anesthesia, in an outpatient plastic surgery clinic, the nurse staff recorded PVI (%) values by MightySat® Masimo finger oximeter pulse and the hours of fasting carried out the night before their admission by direct interrogation of the patient. a simple linear regression with Pearson correlation coefficient, perfect = 1, to find a relation between fasting hours and PVI, being considered significant with a p&lt; 0.05. Results: 140 patients were included, women (90%), mean age 35 years, the mean PVI values were 21.01 (SD +/- 7.20) means hours of preoperative fasting performed by patients 11.85 (SD+/- 2.34). Pearson correlation coefficient between fasting hours and PVI was 0.005 (t-student 0.0054, p bilateral 0.47) Conclusion: This study did not show a linear relation, direct or inverse, between fasting hours and PVI values. PVI as a dynamic measurement of preload or stroke volume did not show changes in terms of fasting time in our patients.

Evaluation of plethysmographic variability index and hemoglobin monitoring in patients who underwent laparoscopic cholecystectomy.

The aim of the study was to determine the interaction of Pleth Variability Index, Perfusion Index (PI) and Peripheral Blood Hemoglobin (SpHb) values during the surgical phases of laparoscopic cholecystectomy. After the approval of the Ethics Committee, the patients who experienced laparoscopic cholecystectomy between October 2020 and January 2021 in our hospital were included in the study. We analyzed peripheral blood hemoglobin, pleth variability index, and the perfusion index values of 87 patients who underwent cholecystectomy. We performed the study with Masimo Radical 7 pulse oximeter probe (Masimo Radical 7; Masimo Corp., Irvine, CA, USA) in this present study. According to the analysis of our results it has been found that hemoglobin, T5, T6, T7 values were found to be significantly higher than T3, T4, T8 values (p<0.05). The PVI T4 value was the highest within the periods, and it was found to be statistically significantly higher between T5, T6, and T7 values (p<0.05). Close values were detected in PI, T1 and T8 periods. T2 value measured during the period of mechanical ventilator was found to be significantly higher than the in T1, T3, T6 values (p<0.05). In this study, we followed the SpHb, SPOC, and ORI values in these steps (T1-T8) and investigated the interaction between them. Knowing the response of monitoring to these conditions is important for the treatments to be performed.

The role of perfusion index and plethysmography variability index for predicting dehydration severity in patients with acute gastroenteritis

Background:Acute gastroenteritis is a clinical syndrome that may cause severe dehydration in affected individuals and a reason of mortality and morbidity in all age groups. Measurement of perfusion index and plethysmography variability index may provide emergency physicians valuable information about hemodynamics of the patient.Objectives:Our study aimed to investigate the role of perfusion index and plethysmography variability index measurement at admission for estimating dehydration severity and determiningthe possible change in those parameters after fluid replacement among patients presenting to emergency department with acute gastroenteritis.Methods:This was a prospective cross‐sectional study. Patients diagnosed with acute gastroenteritis at the emergency department were consecutively enrolled. The two groups were defined according to the severity of dehydration: mild and moderate/severe dehydration groups. The values of perfusion index and plethysmography variability index of all patients were measured.Results:A total of 180 patients were included in the study. As compared with the mild dehydration group, moderate/severe dehydration group had a significantly lower perfusion index value and significantly higher plethysmography variability index value on admission (p &lt; 0.001 for both comparisons). Among moderate/severe dehydration patients, perfusion index value significantly increased and plethysmography variability index significantly decreased after treatment (p &lt; 0.001). There was a significant positive correlation between osmolarity and plethysmography variability index (r = 0.298; p = 0.007) and a significant negative correlation between osmolality and perfusion index (r = −0.259; p = 0.019) in the patients with moderate/severe dehydration.Conclusion:The study show that perfusion index and plethysmography variability index may be useful for determining the severity of dehydration in acute gastroenteritis and may be use for assessing the response to fluid replacement especially in patients with severe dehydration at emergency department.

Dynamic variables predict fluid responsiveness in pre-school and school children undergoing neurosurgery: a prospective observational study.

BackgroundThe evidence that plethysmographic variability index (PVI), pulse pressure variation (PPV), FloTrac/Vigileo-derived stroke volume variation (SVV), and Eadyn (dynamic arterial elastance) predict fluid responsiveness in children is limited by conflicting results. We aim to evaluate their accuracy and reliability to predict fluid responsiveness after induction in children aged 4–9 years undergoing major neurosurgery.MethodsChildren aged 4–9 years undergoing intracranial epileptic foci excision were enrolled. After the induction of anesthesia, fluid loading with 10 mL/kg of Ringer’s solution over 10 min was administered before surgical incision. PVI, PPV, SVV, and Eadyn were measured before and within 5 min after fluid loading. Respiratory variation in aortic blood flow peak velocity (∆Vpeak) >15% at baseline, measured using transthoracic echocardiography, identified fluid “responders”. The abilities of dynamic variables to predict an increase in mean arterial pressure (MAP) of >10% following fluid loading were also assessed.ResultsFourteen (31.8%) of forty-four patients were responders defined by a baseline ∆Vpeak >15%. Before fluid loading, only the PVI value was significantly different between R and NR (P=0.017). Baseline PVI showed fair diagnostic accuracy for fluid responsiveness, with an area under the curve (AUROC) of 0.735 and the cutoff value of 13%. The R group showed a significantly greater absolute change in PPV and SVV after fluid loading from baseline compared with the NR group (P=0.021 and 0.040, respectively). The absolute change in the PPV and SVV values from baseline was greater in R than those in NR (P=0.021 and 0.040, respectively). Twenty (45.5%) showed a MAP increase of >10% following fluid loading and were defined as responders. Baseline ∆Vpeak and SVV showed fair predictive values for a MAP increase of >10% (AUROC =0.758 and 0.715, respectively).ConclusionsPVI at baseline showed fair reliability to predict fluid responsiveness after anesthesia induction in mechanically ventilated children aged 4–9 years undergoing neurosurgery. Baseline ∆Vpeak and SVV were fairly predictive for an increase in MAP following fluid loading.

Use of a modified passive leg raise maneuver as a volumetric predictor of fluid responsiveness during experimental induction and correction of hypovolemia in anesthetized dogs

Introduction: Modified passive leg raise maneuver (PLR) was studied as a predictor of fluid responsiveness, via transient effects on cardiac output (CO) and plethysmographic variability index (PVI) in dogs during induction and correction of hypovolemia.

Goal-Directed Fluid Management Using Plethysmographic Variability Index in Patients Undergoing Laparoscopic Bariatric Surgery

Background: Optimal intraoperative fluid management is essential in surgical patients, including individuals with obesity undergoing bariatric surgery. The objective of this study was to assess the...

Comparison of pulse pressure variation, stroke volume variation, and plethysmographic variability index in pediatric patients undergoing craniotomy

Objective To compare well-known preload dynamic parameters intraoperatively including stroke volume variation (SVV), pulse pressure variation (PPV), and plethysmographic variability index (PVI) in children who underwent craniotomy for epileptogenic lesion excision. Methods A total of 30 children aged 0 to 14 years undergoing craniotomy for intracranial epileptogenic lesion excision were enrolled. During surgery, we measured PPV, SVV (measured by the Flotrac/Vigileo device), and PVI (measured by the Masimo Radical-7 monitor) simultaneously and continuously. Preload dynamic parameter measurements were collected at predefined steps: after induction of anesthesia, during opening the skull, intraoperative electroencephalogram monitoring, excision of epileptogenic lesion, skull closure, at the end of the operation. After exclusion of outliers, agreement among SVV, PPV, and PVI was assessed using repeated measures of Bland-Altman approach. The 4-quadrant and polar plot techniques were used to assess the trending ability among the changes in the three parameters. Results The mean SVV, PPV, and PVI were 8%±2%, 10%±3%, and 15%±7%, respectively during surgery. We analyzed a total of 834 paired measurements (3 to 8 data sets for each phase per patient). Repeated measures Bland-Altman analysis identified a bias of -2.3 and 95% confidence intervals between -1.9 and -2.7 (95% limits of agreement between -6.0 and 1.5) between PPV and SVV, showing significant correlation at all periods. The bias between PPV and PVI was -5.0 with 95% limits of agreement between -20.5 and 10.5, and that between SVV and PVI was -7.5 with 95% limits of agreement between -22.7 and 7.8, both not showing significant correlation. Reflected by 4-quadrant plots, the con-cordance rates showing the trending ability between the changes in PPV and SVV, PPV and PVI, SVV and PVI were 88.6%, 50.4%, and 50.1%, respectively. The concordance rate between PPV and SVV was higher (92.7%) in children aged less than 3 years compared with those aged 3 and more than 3 years. The mean angular bias, radial limits of agreement, and angular concordance rate in the polar analysis were not clinically acceptable in the changes between arterial pressure waveform-based parameters and volume-based PVI (PPV vs. PVI: angular mean bias 8.4°, angular concordance rate 29.9%; SVV vs. PVI: angular mean bias 2.4°, angular concordance rate 29.1%). There was a high concordance between the two arterial pressure waveform-based parameters reflected by the polar plot (angular mean bias -0.22°, angular concordance rate 86.6%). Conclusion PPV can be viewed as a surrogate for SVV, especially in children aged less than 3 years. The agreement between arterial pressure waveform-based preload parameters (PPV and SVV) and PVI is poor and these two should not be considered interchangeable. Attempt to combine PVI and PPV for improving the anesthesiologist's ability to monitor cardiac preload in major pediatric surgery is warranted.

Correlation coefficient between plethysmographic variability index and Systolic Pressure Variation as an indicator for fluid responsiveness in hypotensive patients in the ICU/OT

BackgroundPrediction of fluid responsiveness in hypotensive patients is a challenge. The correlation between a novel noninvasive dynamic indicator, Pleth Variability Index (PVI ®), and a gold-standard Systolic Pressure Variation (SPV) as a measure of fluid responsiveness was assessed in the Intensive Care Unit (ICU) or Operation Theatre (OT) in a tertiary care hospital. MethodsA prospective experimental study was conducted over a span of one year on 100 mechanically ventilated patients with hypotension. Vital parameters along with SPV and PVI ® were recorded before and after a standard volume expansion protocol. A 10% SPV threshold was used to define fluid responders and nonresponders. ResultsPearson’s correlation graph at baseline showed positive correlation between PVI ® and SPV (r = 0.59, p-value = 0.001). Strength of correlation was comparatively less but still showed positive correlation at 15 (r = 0.39, p-value = 0.009) and 30 (r = 0.404, p-value = 0.004) minutes of fluid bolus. The Bland Altman analysis of baseline values of PVI ® and SPV showed good agreement with a mean bias of 9.05. Percentage change of PVI ® and SPV over 30 min showed a statistically significant positive correlation in the responder group (r = 0.53, p < 0.05). A threshold value of PVI ® more than 18% before volume expansion differentiated fluid responders and nonresponders with a sensitivity of 75% and specificity of 67%, with an area under Receiver Operating Characteristic (ROC) of 0.78. ConclusionA positive correlation exists between SPV and PVI ®, justifying the use of noninvasive PVI ® in a clinical setting of hypotension.

Evaluation of Brachial Plexus Block With Plethysmographic Variability Index and Perfusion Index

Amaç: Blok başarısının değerlendirilmesi kullanılan için geleneksel yöntemler zaman alıcıdır ve hasta kooperasyonuna ihtiyaç duyar. Bu çalışmanın amacı Perfüzyon İndeksi ve Pletismografik Variabilite İndeksinin brakiyal sinir blokajının başarısını tahmin etmek için kullanılıp kullanılamayacağını değerlendirmektir. Materyal ve metod: Bu çalışmaya 18-65 yaş arası, elektif veya acil cerrahi operasyona alınan 34 hasta dahil edildi. Brakial pleksus bloğu uygulandı. Kardiyak hastalığı, kronik obstrüktif akciğer hastalığı ve astım hastalığı olanlar çalışma dışı bırakıldı. Hastaların yatak başı, noninvaziv, seri pletismografik variabilite indeksi (PVI) ve perfüzyon indeksi (PI) ölçümleri, blok uygulanan elin dördüncü parmak ucundan Radical-97 Pulse Oksimetre cihazı kullanılarak yapıldı. Bulgular: Blok yapılan koldan ölçülen PVI değerleri karşılaştırıldığında; 0 ile 5. dk, 5. dk ile 10. dk ve 0 ile 10.dk arasındaki farklılık istatistiksel olarak anlamlı bulundu. PI değerleri 0 ve 5.dk, 5 ve 10.dk, 0 ve 10.dk olarak karşılaştırıldığında değişimler istatistiksel olarak anlamlı bulundu. ( p&amp;lt;0.05) Sonuç: Çalışmamızda PI ve PVI değerindeki değişimlerin istatistiksel olarak anlamlı olduğu görüldü. ( p&amp;lt;0.05) PVI ve PI arasında istatistiksel olarak anlamlı korelasyon saptanmadı.

Plethysmography Variability Index and Stroke Volume Variation Changes in Relation to Central Venous Pressure Changes During Living Related Donor Right Hepatotomy: A Diagnostic Test Accuracy.

During donor hepatectomy, we investigated (1) the Electrical Cardiometry associations and agreements between noninvasive plethysmography variability index and noninvasive stroke volume variation, (2) their association with central venous pressure, and (3) their ability to monitor intraoperative changes and discriminate donors with increased blood loss. A diagnostic test accuracy was applied among donors (American Society of Anesthesiologists classification I). Data were recorded at 10 minutes after anesthesia induction, hourly during dissection, after resection, and at end of surgery. Crystalloids were restricted during resection to reduce central venous pressure but were otherwise infused to maintain mean invasive arterial blood pressure >60 mm Hg and urine output >0.5 mL/kg/h. All 34 donors were related. Sons or daughters represented 58.8% (median age 26.0 years [interquartile range, 21.0-34.0]). Median values (with interquartile ranges) were anesthesia time, 7.5 hours (7.0-8.0); blood loss, 400 mL (400.0-500.0); infused acetated Ringer solution, 4000.0 mL (3500.0-4500.0); colloids, 250.0 mL (0-500.0); and urine output, 1.4 mL/kg/h (1.30-1.7). No blood products were transfused. Central venous pressure showed negligible negative correlations for both plethysmography variability index and stroke volume variation. Plethysmography variability index showed negligible correlation and poor agreement with stroke volume variation (P < .001, with intraclass correlation = 0.213 and a relatively wide bias; 95% CI, 0.03-0.37). All 3 methods reflected a state of normovolemia despite fluid restriction during resection and were unable to discriminate donors with increased blood loss (>400 mL). Plethysmography variability index and stroke volume variation showed negligible correlation and poor agreement with central venous pressure. Transfusion-free dissection was possible despite normovolemia, with median values of 8 mm Hg central venous pressure, 10% stroke volume variation, and 12% plethysmography variability index. Plethysmography variability index and stroke volume variation were unable to discriminate donors with increased blood loss.

The Analysis of Perfusion Index and Plethysmographic Variability Index During Elective Cesarean Section

The Analysis of Perfusion Index and Plethysmographic Variability Index During Elective Cesarean Section

Pleth variability index may predict preload responsiveness in patients treated with nasal high flow: a physiological study.

The purpose of this study was to determine whether the plethysmographic variability index ("PVi") can predict preload responsiveness in patients with nasal high flow (NHF) (≥30 L/min) with any sign of hypoperfusion. "Preload responsiveness" was defined as a ≥10% increase in stroke volume (SV), measured by transthoracic echocardiography, after passive leg raising. SV and PVi were reassessed in preload responders after receiving a 250-mL fluid challenge. Twenty patients were included and 12 patients (60%) were preload responders. Responders showed higher baseline mean PVi (24% vs. 13%; P = 0.001) and higher mean PVi variation (ΔPVi) after passive leg raising (6.8% vs. -1.7%; P < 0.001). No differences between mean ΔPVi after passive leg raising and mean ΔPVi after fluid challenge were observed (6.8% vs. 7.4%; P = 0.24); and both values were strongly correlated (r = 0.84; P < 0.001). Baseline PVi and ΔPVi after passive leg raising showed excellent diagnostic accuracy identifying preload responders (AUROC 0.92 and 1.00, respectively). Baseline PVi ≥ 16% had a sensitivity of 91.7% and a specificity of 87.5% for detecting preload responders. Similarly, ΔPVi after passive leg raising ≥2% had a 100% of both sensitivity and specificity. Thus, PVi might predict "preload responsiveness" in patients treated with NHF, suggesting that it may guide fluid administration in these patients.NEW & NOTEWORTHY This is the first study that analyzes the use of noninvasive plethysmographic variability index (PVi) for preload assessment in patients treated with nasal high flow (NHF). Its results showed that PVi might identify preload responders. Therefore, PVi may be used in the day-to-day clinical decision-making process in critically ill patients treated with NHF, helping to provide adequate resuscitation volume.

Effect of fluid strategy on stroke volume, cardiac output, and fluid responsiveness in adult patients undergoing major abdominal surgery: a sub-study of the Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial

BackgroundWe designed a prospective sub-study of the larger Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial to measure differences in stroke volume and other haemodynamic parameters at the end of the intraoperative fluid protocols. The haemodynamic effects of the two fluid regimens may increase our understanding of the observed perioperative outcomes. MethodsStroke volume and cardiac output were measured with both an oesophageal Doppler ultrasound monitor and arterial pressure waveform analysis. Stroke volume variation, pulse pressure variation, and plethysmographic variability index were also obtained. A passive leg raise manoeuvre was performed to identify fluid responsiveness. ResultsAnalysis of 105 patients showed that the primary outcome, Doppler monitor-derived stroke volume index, was higher in the liberal group: restrictive 38.5 (28.6–48.8) vs liberal 44.0 (34.9–61.9) ml m−2; P=0.043. Similarly, there was a higher cardiac index in the liberal group: 2.96 (2.32–4.05) vs 2.42 (1.94–3.26) L min−1 m−2; P=0.015. Arterial-pressure-based stroke volume and cardiac index did not differ, nor was there a significant difference in stroke volume variation, pulse pressure variation, or plethysmographic variability index. The passive leg raise manoeuvre showed fluid responsiveness in 40% of restrictive and 30% of liberal protocol patients (not significant). ConclusionsThe liberal fluid group from the RELIEF trial had significantly higher Doppler ultrasound monitor-derived stroke volume and cardiac output compared with the restrictive fluid group at the end of the intraoperative period. Measures of fluid responsiveness did not differ significantly between groups. Clinical trial registrationACTRN12615000125527.

Intraoperative Assessment of Fluid Responsiveness in Normotensive Dogs under Isoflurane Anaesthesia.

The aim of this study was to evaluate the incidence of fluid responsiveness (FR) to a fluid challenge (FC) in normotensive dogs under anaesthesia. The accuracy of pulse pressure variation (PPV), systolic pressure variation (SPV), stroke volume variation (SVV), and plethysmographic variability index (PVI) for predicting FR was also evaluated. Dogs were anaesthetised with methadone, propofol, and inhaled isoflurane in oxygen, under volume-controlled mechanical ventilation. FC was performed by the administration of 5 mL/kg of Ringer’s lactate within 5 min. Cardiac index (CI; L/min/m2), PPV, (%), SVV (%), SPV (%), and PVI (%) were registered before and after FC. Data were analysed with ANOVA and ROC tests (p < 0.05). Fluid responsiveness was defined as 15% increase in CI. Eighty dogs completed the study. Fifty (62.5%) were responders and 30 (37.5%) were nonresponders. The PPV, PVI, SPV, and SVV cut-off values (AUC, p) for discriminating responders from nonresponders were PPV >13.8% (0.979, <0.001), PVI >14% (0.956, <0.001), SPV >4.1% (0.793, <0.001), and SVV >14.7% (0.729, <0.001), respectively. Up to 62.5% of normotensive dogs under inhalant anaesthesia may be fluid responders. PPV and PVI have better diagnostic accuracy to predict FR, compared to SPV and SVV.

Comparison of perfusion index and echocardiographic parameters in preterm infants with hemodynamically significant patent ductus arteriosus

Background/Aim: The aim of the study was to compare echocardiographic parameters and the perfusion index (PI) and plethysmographic variability index (PVI) values obtained by routine pulse oximetry in the diagnosis of hemodynamically significant patent ductus arteriosus (hsPDA). Materials and Methods: This prospective study was conducted between 2016 and 2017 at the HacettepeUniversity Neonatal Intensive Care Unit. The study included premature neonates who had a birth weight below 1500 g. Patients were routinely monitored from the right wrist and right foot using a pulse oximeter (Masimo Radical-7® Pulse CO-Oximetry), and PI and PVI values were recorded. The difference between right-hand and right-leg PI values was calculated as the delta PI (ΔPI). A cardiologist blinded to the results evaluated the presence of patent ductus arteriosus (PDA) with echocardiography on postnatal days 1th, 3rd, and 7th. Results: Of the 66 preterm neonates included in the study, 23 had hsPDA. On postnatal day 1, the hsPDA group had a significantly greater ductal diameter, PDA/left pulmonary artery (LPA) ratio, and left ventricle (LA)/aortic (Ao) ratio (P

Perfusion indices can predict early volume depletion in a blood donor model.

Blood donation from healthy donors is used experimental model that surrogates for class 1 hemorrhage in humans. We examined changes in the perfusion index (PI) and plethysmographic variability index (PVI) in healthy blood donors after donating a unit of blood, and we evaluated the usability of these indices in detecting blood loss volumes of less than 750mL (class 1 hemorrhagic shock trauma patients). This study is a prospective, cross-sectional study. 180 healthy volunteers aged 18 and over, who donated blood at the local blood bank, were included in the study consecutively. The age, gender, and body mass index of the volunteers were recorded and, before and after the blood donation, the vital signs and perfusion indices were measured. Of the donors, 61.7% were men (n = 111), and the median age of all donors was 32 (IQR: 21-39). A statistically significant difference was found between the hemodynamic parameters and PIs before and after the blood donation (p < 0.01 for all parameters; median difference of PI [-1.45, 95% CI: (-0.9)-( -2)], median difference of PVI [6, 95% CI: 7.77-4.23]. We evaluated the perfusion indices in the early diagnosis of blood volume loss in patients admitted to the emergency department due to trauma. After the participants donated one unit of blood, we found that their PI decreased and PVI increased compared to the measurements before the blood donation. Considering that major bleeding starts in the very early stage as minor bleeding, it is essential for emergency physicians to recognize class 1 hemorrhagic shock patients. Further, non-invasive and straightforward procedures, such as measuring PI and PVI, can be particularly useful in identifying blood loss volumes of less than 750mL.

Plethysmography variability index (PVI) changes in preterm neonates with shock-an observational study.

Shock is an acute state of circulatory dysfunction. The diagnosis of shock is complex in neonates. The relative sensitivity of current clinical or laboratory findings for detecting shock is largely unknown, especially for preterm neonates. For preload assessment, inferior vena cava (IVC) collapsibility can be a useful bedside echocardiography parameter. plethysmography variability index (PVI) is a marker of fluid responsive shock in adults and children, but not well defined in neonates. In this prospective observational study, we evaluated the changes in PVI in preterm neonates with shock. Among the 37 infants enrolled in the study, the mean blood pressure (MAP) was 45 (± 4mm of Hg) and none of infants had hypotension. The mean pulse pressure was 28mm of Hg, the mean PVI was 28% (±5), the mean arterial blood gas pH was 7.20 (±0.07), and the mean base deficit was 9.9 (±2.53) at the onset of shock. Thirty (96.77%) of the 31 infants with resolution of shock showed decrease in PVI with an average decrease of 11% (±5).Conclusion: Significant proportion of neonates show an increase in PVI at the onset of shock. What is Known: • Plethysmography Variability Index (PVI) is commonly used as a marker of volume status in paediatric population. • Changes in PVI may guide in giving volume boluses in patients with shock. What is New: • This study provides information of changes in PVI in preterm neonates with shock. • PVI may become a valuable tool to be used at bedside in preterm infants with shock.