Plethysmographic Variability Index Research Articles

Plethysmography variability index guided fluid management is superior to conventional approach for elective urological surgery in children - a prospective randomised controlled trial.

Plethysmography variability index guided fluid management is superior to conventional approach for elective urological surgery in children - a prospective randomised controlled trial.

Diagnostic accuracy of Plethysmographic Variability Index for the prediction of high pulse pressure variation in neurosurgery using a gray-zone approach: a retrospective study

Diagnostic accuracy of Plethysmographic Variability Index for the prediction of high pulse pressure variation in neurosurgery using a gray-zone approach: a retrospective study

Plethysmography variation index versus pulse pressure variation as an indicator of fluid responsiveness in colorectal surgeries during immediate postoperative period

ABSTRACT Background During major abdominal surgery, goal-directed fluid therapy may lessen postoperative morbidity. It has been demonstrated that the Plethysmography Variability Index (PVI), which is generated from the pulse oximeter waveform, can predict fluid responsiveness in a variety of surgical settings. Pulse pressure variation (PPV), one of the indicators of fluid responsiveness, has received the most research attention and clinical application of all the indicators. Through arterial cannulation, primarily the radial artery, pulse pressure fluctuation is recorded. The cyclic variations in intrathoracic pressure have less of an immediate impact on pulse pressure than they do on systolic pressure. In this study, sedated, intubated, mechanically ventilated patients admitted for postoperative resuscitation in our surgical ICU following colorectal surgeries had their fluid responsiveness assessed using the Plethysmography Variation Index (PVI) and the Pulse Pressure Variation (PPV) to compare their effectiveness and reliability.

Goal-directed fluid therapy guided by plethysmographic variability index versus conventional liberal fluid therapy in neonates undergoing abdominal surgery: A prospective randomized controlled trial.

Intraoperative fluid therapy maintains normovolemia, normal tissue perfusion, normal metabolic function, normal electrolytes, and acid-base status. Plethysmographic variability index has been shown to predict fluid responsiveness but its role in guiding intraoperative fluid therapy is still elusive. The aim of the present study was to compare intraoperative goal-directed fluid therapy based on plethysmographic variability index with liberal fluid therapy in term neonates undergoing abdominal surgeries. A prospective randomized controlled study was conducted in a tertiary care centre, over a period of 18 months. A total of 30 neonates completed the study out of 132 neonates screened. Neonates with tracheoesophageal fistula, congenital diaphragmatic hernia, congenital heart disease, respiratory disorders, creatinine clearance <90 mL/min and who were hemodynamically unstable were excluded. Neonates were randomized to goal-directed fluid therapy group where the plethysmographic variability index was targeted at <18 or liberal fluid therapy group. Primary outcome was comparison of total amount of fluid infused intraoperatively in both the groups. Secondary outcomes included intraoperative and postoperative arterial blood gas parameters, biochemical parameters, use of vasopressors, number of fluid boluses, complications and duration of hospital stay. There was no significant difference in total intraoperative fluid infused [90 (84-117.5 mL) in goal-directed fluid therapy and 105 (85.5-144.5 mL) in liberal fluid therapy group (p = .406)], median difference (95% CI) -15 (-49.1 to 19.1). There was a decrease in serum lactate levels in both groups from preoperative to postoperative 24 h. The amount of fluid infused before dopamine administration was significantly higher in liberal fluid therapy group (58 [50.25-65 mL]) compared to goal-directed fluid therapy group (36 [22-44 mL], p = .008), median difference (95% CI) -22 (-46 to 2). In postoperative period, the total amount of fluid intake over 24 h was comparable in two groups (222 [204-253 mL] in goal-directed fluid therapy group and 224 [179.5-289.5 mL] in liberal fluid therapy group, p = .917) median difference (95% CI) cutoff -2 (-65.3 to 61.2). Intraoperative plethysmographic variability index-guided goal-directed fluid therapy was comparable to liberal fluid therapy in terms of total volume of fluid infused in neonates during perioperative period. More randomized controlled trials with higher sample size are required. Central Trial Registry of India (CTRI/2020/02/023561).

PASS: A scoring system to evaluate persistent kidney injury in critically ill ICU adult patients

Background We evaluated if the course of recovery from sepsis-induced acute kidney injury (AKI) can be predicted using variables collected at admission. Methods A total of 63 patients admitted for sepsis-induced AKI in our Mangalore ICU were evaluated and baseline demographic and clinical/laboratory parameters, including serum creatinine (SCr), base excess (BE), Plethysmographic Variability Index (PVI), Caval Index, R wave variability index (RVI), mean arterial pressure (MAP) and renal resistivity index (RI) using renal doppler and need for inotropes were assessed on admission. Patients were managed as per standard protocol. After six hours of fluid resuscitation, patients were classified as volume responders or non-responders. Re-assessment was done at 24 hours and 72 hours after admission. Primary outcome was persistent AKI after 72 hours. Secondary outcome was initiation of dialysis or death within 15 days of admission. Results A total of 34 subjects recovered from AKI, of whom 32 patients were volume responders and 31 were non-responders. Response to fluid, MAP at admission and six hours, BE at admission, inotrope requirement, and PVI at admission did not correlate with recovery. Multiple logistic regression showed that SCr &lt; 2.36 mg%, RVI &gt; 14.45 and RI &lt; 0.8 on admission correlated with recovery and they were evaluated further to model AKI recovery and develop PASS. PASS score = (SCr points × 5.4) + (RVI points × 4.0) + (RI points × 6.2). One point each was allotted if SCr was &lt; 2.36, RVI was &gt; 14.45 and RI was &lt;0.8, and 0 otherwise. A score &gt; 7.8 predicted recovery with a sensitivity of 79.4%, specificity of 72.4%, PPV 81.8%, NPV 76.7% and AuROC of 0.85. Conclusions The PASS score can be used to identify salvageable cases of sepsis-AKI, guiding fluid resuscitation and aiding early referral from rural to tertiary care centers for better management.

Plethysmographic variability index as intraoperative fluid therapy guide in dogs

Plethysmographic variability index as intraoperative fluid therapy guide in dogs

Passive leg raising test induced changes in plethysmographic variability index to assess fluid responsiveness in critically ill mechanically ventilated patients with acute circulatory failure

BackgroundPassive leg raising (PLR) reliably predicts fluid responsiveness but requires a real-time cardiac index (CI) measurement or the presence of an invasive arterial line to achieve this effect. The plethysmographic variability index (PVI), an automatic measurement of the respiratory variation of the perfusion index, is non-invasive and continuously displayed on the pulse oximeter device. We tested whether PLR-induced changes in PVI (ΔPVIPLR) could accurately predict fluid responsiveness in mechanically ventilated patients with acute circulatory failure. MethodsThis was a secondary analysis of an observational prospective study. We included 29 mechanically ventilated patients with acute circulatory failure in this study. We measured PVI (Radical-7 device; Masimo Corp., Irvine, CA) and CI (Echocardiography) before and during a PLR test and before and after volume expansion of 500 mL of crystalloid solution. A volume expansion-induced increase in CI of >15% defined fluid responsiveness. To investigate whether ΔPVIPLR can predict fluid responsiveness, we determined areas under the receiver operating characteristic curves (AUROCs) and gray zones for ΔPVIPLR. ResultsOf the 29 patients, 27 (93.1%) received norepinephrine. The median tidal volume was 7.0 [IQR: 6.6–7.6] mL/kg ideal body weight. Nineteen patients (65.5%) were classified as fluid responders (increase in CI > 15% after volume expansion). Relative ΔPVIPLR accurately predicted fluid responsiveness with an AUROC of 0.89 (95%CI: 0.72–0.98, p < 0.001). A decrease in PVI ≤ −24.1% induced by PLR detected fluid responsiveness with a sensitivity of 95% (95%CI: 74–100%) and a specificity of 80% (95%CI: 44–97%). Gray zone was acceptable, including 13.8% of patients. The correlations between the relative ΔPVIPLR and changes in CI induced by PLR and by volume expansion were significant (r = −0.58, p < 0.001, and r = −0.65, p < 0.001; respectively). ConclusionsIn sedated and mechanically ventilated ICU patients with acute circulatory failure, PLR-induced changes in PVI accurately predict fluid responsiveness with an acceptable gray zone. Trial registrationClinicalTrials.govNCT03225378.

Intraoperative plethysmography variability index directed fluid management versus standard care during intraabdominal surgery in cancer patients

Background: During the past 20 years, numerous publications have described the usefulness of systolic pressure variation, pulse pressure variation, stroke volume variation, etc., to guide intraoperative fluid administration. However, we still lack robust noninvasive physiological variables to successfully predict the response to fluid loading. Aims and Objectives: The present study was designed to evaluate the utility of plethysmography variability index (PVI) to optimize fluid management during intra-abdominal surgery in cancer patients. Materials and Methods: After the Institutional Ethics Committee approval and consent, 60 patients scheduled for elective lower abdominal cancer surgeries were randomized to receive fluid by either PVI-directed management (2 mL/kg/h) or using central venous pressure (8 mL/kg/h) after standardized technique of general and lumbar epidural anesthesia. The PVI was calculated by measuring changes in the PI during the respiratory cycle (PVI = [(PImax - PImin)/PImax] × 100). Arterial blood samples were taken at the time of incision and after 6 h postoperatively. Instances of intraoperative hypotension and oliguria were recorded. Results: Among the 60 patients enrolled in the study, demographic data, ASA status, duration of surgery, and hemodynamics were found to be comparable. The amount of crystalloid given was significantly lesser in Group P (984.70±51.16) as compared to Group C (2395.27±209.68) (P&lt;0.001). Four patients in Group P and three patients in Group C required vasopressors. Conclusion: The use of PVI-guided fluid management was associated with lower lactate levels and crystalloid requirement. Reduced lactate levels in PVI-guided patients suggest that PVI-guided fluid management may be tailored to everyone’s needs.

PASS: A scoring system to evaluate persistent kidney injury in critically ill ICU adult patients

Background: We evaluated if the course of recovery from sepsis-induced acute kidney injury (AKI) can be predicted using variables collected at admission. Methods: A total of 63 patients admitted for sepsis-induced AKI in our Mangalore ICU were evaluated and baseline demographic and clinical/laboratory parameters, including serum creatinine (SCr), base excess (BE), Plethysmographic Variability Index (PVI), Caval Index, R wave variability index (RVI), mean arterial pressure (MAP) and renal resistivity index (RI) using renal doppler and need for inotropes were assessed on admission. Patients were managed as per standard protocol. After six hours of fluid resuscitation, patients were classified as volume responders or non-responders. Re-assessment was done at 24 hours and 72 hours after admission. Primary outcome was persistent AKI after 72 hours. Secondary outcome was initiation of dialysis or death within 15 days of admission. Results: A total of 34 subjects recovered from AKI, of whom 32 patients were volume responders and 31 were non-responders. Response to fluid, MAP at admission and six hours, BE at admission, inotrope requirement, and PVI at admission did not correlate with recovery. Multiple logistic regression showed that SCr &lt; 2.36 mg%, RVI &gt; 14.45 and RI &lt; 0.8 on admission correlated with recovery and they were evaluated further to model AKI recovery and develop PASS. PASS score = (SCr points × 5.4) + (RVI points × 4.0) + (RI points × 6.2). One point each was allotted if SCr was &lt; 2.36, RVI was &gt; 14.45 and RI was &lt;0.8, and 0 otherwise. A score &gt; 7.8 predicted recovery with a sensitivity of 79.4%, specificity of 72.4%, PPV 81.8%, NPV 76.7% and AuROC of 0.85. Conclusions: The PASS score can be used to identify salvageable cases of sepsis-AKI, guiding fluid resuscitation and aiding early referral from rural to tertiary care centers for better management.

Role of perfusion index and plethysmography variability index for predicting outcomes in neonatal sepsis.

(i) To compare perfusion index (PI) and plethysmography variability index (PVI) between neonates with proven or probable sepsis versus no-sepsis, (ii) to examine an association of PI and PVI with in-hospital mortality. We enrolled neonates with clinically presumed sepsis. Culture-proven or probable sepsis were categorised as 'cases' and no-sepsis as 'controls'. PI and PVI were recorded hourly for 120 h and averaged in 20-time epochs (0-6 h to 115-120 h). We analysed 148 neonates with sepsis (proven sepsis = 77, probable sepsis = 71) and 126 with no-sepsis. Neonates with proven/probable sepsis and no-sepsis had comparable PI and PVI values. Among 148 neonates with sepsis, 43 (29%) died. Non-survivors had significantly lower PI values than survivors (mean difference 0.21 [95% CI 0.14-0.29], p-value <0.001). PI had a significant but modest discriminative ability to identify non-survivors. However, PI did not independently predict mortality. Neonates with proven/probable sepsis and no-sepsis had comparable PI and PVI values in the first 120 h of sepsis. PI but not PVI values were significantly lower in non-survivors than survivors. PI did not independently predict in-hospital mortality. Due to modest discriminative ability, PI should be interpreted along with other vital signs to take clinical decisions.

Effects of tidal volume challenge on the reliability of plethysmography variability index in hepatobiliary and pancreatic surgeries: a prospective interventional study

BackgroundThe plethysmography variability index (PVI) is a non-invasive, real-time, and automated parameter for evaluating fluid responsiveness, but it does not reliably predict fluid responsiveness during low tidal volume (VT) ventilation. We hypothesized that in a ‘tidal volume challenge’ with a transient increase in tidal volume from 6 to 8 ml Kg− 1, the changes in PVI could predict fluid responsiveness reliably.MethodWe performed a prospective interventional study in adult patients undergoing hepatobiliary or pancreatic tumor resections and receiving controlled low VT ventilation. The values for PVI, perfusion index, stroke volume variation, and stroke volume index (SVI) were recorded at baseline VT of 6 ml Kg− 1, 1 min after the VT challenge (8 ml Kg− 1), 1 min after VT 6 ml Kg− 1 reduced back again, and then 5 min after crystalloid fluid bolus 6 ml kg− 1 (actual body weight) administered over 10 min. The fluid responders were identified by SVI rise ≥ 10% after the fluid bolus.ResultsThe area under the receiver operating characteristic curve for PVI value change (ΔPVI6–8) after increasing VT from 6 to 8 ml Kg− 1 was 0.86 (95% confidence interval, 0.76–0.96), P < 0.001, 95% sensitivity, 68% specificity, and with best cut-off value of absolute change (ΔPVI6–8) = 2.5%.ConclusionIn hepatobiliary and pancreatic surgeries, tidal volume challenge improves the reliability of PVI for predicting fluid responsiveness and changes in PVI values obtained after tidal volume challenge are comparable to the changes in SVI.

Volumetric evaluation of fluid responsiveness using a modified passive leg raise maneuver during experimental induction and correction of hypovolemia in anesthetized dogs

ObjectiveTo demonstrate if modified passive leg raise (PLRM) maneuver can be used for volumetric evaluation of fluid responsiveness (FR) by inducing cardiac output (CO) changes during experimental induction and correction of hypovolemia in healthy anesthetized dogs. The effects of PLRM on plethysmographic variability index (PVI) and pulse pressure variation (PPV) were also investigated. Study designProspective, crossover study. AnimalsA total of six healthy anesthetized Beagle dogs. MethodsDogs were anesthetized with propofol and isoflurane. They were mechanically ventilated under neuromuscular blockade, and normothermia was maintained. After instrumentation, all dogs were subjected to four stages: 1, baseline; 2, removal of 27 mL kg–1 circulating blood volume; 3, after blood re-transfusion; and 4, after 20 mL kg–1 hetastarch infusion over 20 minutes. A 10 minute stabilization period was allowed after induction of each stage and before data collection. At each stage, CO via pulmonary artery thermodilution, PVI, PPV and cardiopulmonary variables were measured before, during and after the PLRM maneuver. Stages were sequential, not randomized. Statistical analysis included repeated measures anova and Tukey’s post hoc test, considering p < 0.05 as significant. ResultsDuring stage 2, PLRM at a 30° angle significantly increased CO (mean ± standard deviation, 1.0 ± 0.1 to 1.3 ± 0.1 L minute–1; p < 0.001), with a simultaneous significant reduction in PVI (38 ± 4% to 21 ± 4%; p < 0.001) and PPV (27 ± 2% to 18 ± 2%; p < 0.001). The PLRM did not affect CO, PPV and PVI during stages 1, 3 and 4. Conclusions and clinical relevanceIn anesthetized dogs, PLRM at a 30° angle successfully detected FR during hypovolemia, and identified fluid nonresponsiveness during normovolemia and hypervolemia. Also, in hypovolemic dogs, significant decreases in PVI and PPV occurred in response to PLRM maneuver.

Correlation of Serum Lactate Levels, Perfusion Index and Plethysmography Variability Index With Invasive Blood Pressure in Late Preterm and Term Infants With Shock

Correlation of Serum Lactate Levels, Perfusion Index and Plethysmography Variability Index With Invasive Blood Pressure in Late Preterm and Term Infants With Shock

Comparison of two techniques of goal directed fluid therapy in elective neurosurgical patients – a randomized controlled study

Background Goal directed fluid therapy (GDFT) may be a rational approach to adopt in neurosurgical patients, in whom intravascular volume optimization is of utmost importance. Most of the parameters used to guide GDFT are derived invasively. We postulated that the total volume of intraoperative intravenous fluid administered during elective craniotomy for supratentorial brain tumours would be comparable between two groups receiving GDFT guided either by the non-invasively derived plethysmography variability index (PVI) or by stroke volume variation (SVV). Methods 60 ASA category 1, 2 and 3 patients between 18 and 70 years of age were randomized to receive intraoperative fluid guided either by SVV (SVV group; n = 31) or PVI (PVI group; n = 29). The total volume of fluid administered intraoperatively was recorded. Serum creatinine was measured before the surgery, at the end of the surgery, 24 h after surgery and on the fifth post-operative day. Arterial cannulation was performed before induction in all patients. Serum lactate was measured before induction, once in 2 h intraoperatively, at the end of the surgery and 24 h after the surgery. Brain relaxation score was assessed by the surgeon during dural opening and dural closure. Patients were followed up till discharge or death. The duration of mechanical ventilation and the duration of hospital stay was noted for all patients. Results The volume of fluid given intraoperatively was significantly higher in the SVV group (p = 0.005). The two groups were comparable with respect to serum lactate and serum creatinine measured at pre-determined time intervals. Brain relaxation score was also comparable between the groups. SVV and PVI displayed moderate to strong correlation intraoperatively. The duration of mechanical ventilation and the length of the hospital stay were comparable between the two groups. Conclusions PVI and SVV are equally effective in guiding GDFT in adults undergoing elective craniotomy for supratentorial brain tumours.

Dynamic variables to predict fluid responsiveness in young children.

The evidence that dynamic variables predict fluid responsiveness in young children is limited by conflicting research results. Sixty patients, 1-3 years of age, undergoing major neurosurgery, received 10mL/kg of Ringer's solution over 10min after anesthesia induction. Respiratory variation in aortic blood flow peak velocity (∆Vpeak), plethysmographic variability index (PVI), FloTrac/Vigileo-derived stroke volume variation (SVV), dynamic arterial elastance (Eadyn ), and pulse pressure variation (PPV) were measured before and following fluid loading. An increase in the cardiac index (CI) of ≥10% following fluid loading identified fluid "responders." Twenty-six patients (43.3%) were fluid responders. Baseline ∆Vpeak was an excellent predictor of a CI increase following fluid loading with an area under the receiver operating characteristic curve (AUROC) of 0.982 (p < 0.001). The PVI showed fair diagnostic accuracy for CI-fluid responsiveness (AUROC 0.775, p < 0.001). Baseline ∆Vpeak and PVI cutoff values were 9.6% and 15%, respectively. PPV, SVV, and Eadyn were not predictors or were poor predictors for CI-fluid responsiveness (AUROC 0.669, 0.653, and 0.533, respectively). Volume-based PVI and ∆Vpeak showed acceptable reliability for fluid responsiveness prediction in young children undergoing major neurosurgery, whereas pressure-based SVV using FloTrac/Vigileo, Eadyn , and PPV did not.

Goal-directed fluid therapy guided by Plethysmographic Variability Index (PVI) versus conventional liberal fluid administration in children during elective abdominal surgery: A randomized controlled trial

BackgroundPVI has been shown to be an accurate predictor of fluid responsiveness in paediatric patients. Evidence regarding the role of PVI to guide intraoperative fluid therapy in paediatric abdominal surgery is lacking. We aimed to assess the effect of PVI-guided fluid therapy on the volume of intraoperative fluids administered and post-operative biochemical and recovery profile in children undergoing elective abdominal surgery. Methods42 children, 6 months-3 years scheduled for elective open bowel surgery were randomised to receive either ‘conventional liberal intraoperative fluids’ (liberal group) or ‘goal-directed intraoperative fluids’ (GDT group). PVI <13 was targeted in the GDT group. The primary outcome was the volume of intraoperative fluids administered. Postoperative serum lactate, base excess, hematocrit, recovery of bowel function and duration of postoperative hospital stay were the secondary outcomes. ResultsThe mean fluid administered intra-operatively was significantly lower in the GDT group as compared to the liberal group (24.1 ± 9.6 mL/kg vs 37.0 ± 8.9 mL/kg, p < 0.001). The postoperative hemoglobin concentration (g%) was significantly lower in the liberal group as compared to the GDT group (8.1 ± 1.3 vs 9.2 ± 1.4, p = 0.008). Recovery of bowel function (hours) was significantly delayed in the liberal group as compared to the GDT group (58.2 ± 17.9 vs 36.5 ± 14.1, p < 0.001). ConclusionIntraoperative PVI-guided fluid therapy significantly reduces the volume of intravenous crystalloids administered to children undergoing open bowel surgery. These children also had faster recovery of bowel function and less hemodilution in the immediate postoperative period, compared to those who received liberal intraoperative fluid therapy.Type of study: Randomized Clinical Trial.Level of evidence: Treatment Study (LEVEL 1).

Transesophageal Doppler corrected flow time versus plethysmography variability index for goal-directed fluid management in cirrhotic patients during liver resection: a randomized controlled trial

Abstract Background Central venous pressure (CVP) readings are affected by several factors. The need to test the technology of noninvasive or minimal invasive monitoring during liver surgery to guide fluids intake is the focus of this trial. Adult hepatic patients undergoing elective open liver resection were randomized into transesophageal Doppler (TED, n = 20) or plethysmography variability index (PVI, n = 20). PVI blinded to anesthetist in TED group (gp) and vice versa. During dissection, crystalloids were restricted to keep corrected flow time (FTc) parameter of TED &lt; 330 msec or PVI &gt; 14%, otherwise infused at 6 ml/kg/h. Following resection, colloids infused if FTc &lt; 330 msec or PVI &gt; 14% despite crystalloids infusion. Primary aim is to compare TED-corrected flow time (FTc, msec) parameter to PVI (%) for guiding intravenous fluids during liver resection. Secondary to study their correlations and each parameter effect on blood loss and consumption, morbidity and intensive care unit (ICU) stay. Results It is presented as median [IQ]. Volumes of crystalloids and colloids guided by FTc and PVI were not different (p = 0.3, p = 0.1, respectively) despite negligible correlations. Normovolemic existed during dissection despite 2 h of fluids restriction. FTc was 327 (320–341) msec, PVI was 11.50 (11.00–14.00) %, and CVP in TED gp 11.00 (10.00–12.00) vs. 9.00 (9.00–11.50) mmHg in PVI gp, p = 0.2. Blood loss was 1500 (475–2000) ml in TED vs. 950 (675–1925) in PVI, p = 0.5. Patients’ % in need for blood transfusion and volumes in TED vs. PVI gps were similar: red blood cells: 30%, 350 (350–350) vs. 40%, 525 (350–700) ml, and p = 0.2. Plasma is 20%, 200 (200–300) vs. 40%, and 400 (200–400) ml, p = 0.3. There was no difference in nausea, vomiting, or ICU stay, (p &gt; 0.05). Conclusions Volume of fluids guided by PVI was not different from that by TED, despite lack of correlation. Transfusion-free dissection was possible for a significant number of patients with normovolemia. Trial registration PACTR201808140151322 (www.pactr.org)

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%.