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Background: Dexmedetomidine, one of the sedatives, has an analgesic effect. We aimed to investigate postoperative analgesia with dexmedetomidine as adjuvants for procedural sedation using perfusion index (PI)., Methods: In this prospective, randomized, case-control, observational study, 72 adult patients, 19-70 years, who were scheduled for chemoport insertion under monitored anesthesia care were performed. According to the group assignment, remifentanil or dexmedetomidine was simultaneously infused with propofol. The primary outcome was PI 30 min after admission to the post anesthesia care unit (PACU). And, pain severity using numerical rating scale (NRS) score and the relationship between NRS score and PI were investigated., Results: During PACU staying, PI values were significantly different between the two groups PI values at 30 min after admission to the PACU were 1.3 (0.9-2.0) in the remifentanil group and 4.5 (2.9-6.8) in the dexmedetomidine group (median difference, 3; 95% CI, 2.1 to 4.2; P < 0.001). The NRS scores at 30 min after admission to the PACU were significantly lower in the dexmedetomidine group (P = 0.002). However, there was a weak positive correlation between NRS score and PI in the PACU (correlation coefficient, 0.188; P = 0.01)., Conclusion: We could not find a significant correlation between PI and NRS score for postoperative pain control. Using PI as a single indicator of pain is insufficient., Trial Registration: Clinical Trial Registry of Korea, https://cris.nih.go.kr : KCT0003501, the date of registration: 13/02/2019., (© 2023. The Author(s).)

Background: Children receiving proton therapy require repeated sedation. In this study, we aimed to investigate the utility of the perfusion index (PI) for evaluating consciousness level during repeated propofol sedation., Methods: In this prospective observational study, children aged from birth to 19 years old scheduled for proton therapy under repeated propofol sedation were enrolled. The primary outcome was the equivalence of PI values 5 min after anesthesia induction on consecutive sedation. Total consumption of propofol during sedation, time to reach the University of Michigan sedation scale (UMSS) score 1 after end of proton therapy, and duration of post-anesthesia care unit (PACU) stay were recorded., Results: The PI values measured 5 min after induction of anesthesia were not equivalent to each other in consecutive sedation except for the second versus third (1st vs. 2nd: 97.5% CI: -1.34, 0.91; p = 0.206, 0.034; 2nd vs. 3rd: 97.5% CI: -0.87, 0.94; p = 0.023, 0.036 3rd vs. 4th: 97.5% CI: -2.08, -0.26; p < 0.99, <0.001; 4th vs. 5th: 97.5% CI: 0.21, 2.28; p < 0.001, >0.99; respectively). In consecutive sedation, there was not a significantly different difference in the time to reach UMSS score 1 (p > 0.99, all) for total consumption of propofol, time to reach UMSS score 1 after the end of proton therapy, and duration of PACU stay., Conclusions: During repeated propofol sedation in children, PI was insufficient to be used as an indicator of consciousness level assessment. However, we suggest that the information related to repeated sedation provided by this study may be helpful in clinical practice., (© 2023 Japan Pediatric Society.)

Photoplethysmography (PPG) has been extensively used for pulse oximetry monitoring in anaesthesia, perioperative and intensive care. However, some components of PPG signal have been employed for other purposes, such as non-invasive haemodynamic monitoring. Perfusion index (PI) is derived from PPG signal and represents the ratio of pulsatile on non-pulsatile light absorbance or reflectance of the PPG signal. PI determinants are complex and interlinked, involving and reflecting the interaction between peripheral and central haemodynamic characteristics, such as vascular tone and stroke volume. Recently, several studies have shed light on the interesting performances of this variable, especially assessing regional or neuraxial block success, and haemodynamic monitoring in anaesthesia, perioperative and intensive care. Nevertheless, no review has yet been published concerning the interest of PI in these fields. In this narrative review will be exposed first the physiological and pathophysiological determinants of PI, and then the mean to measure this value as well as its potential limitations. In the second part, the existing data concerning usefulness of PI in different clinical settings such as operating theatres, intensive care units and emergency departments will be presented and discussed. Finally, the perspectives concerning the use of PI and mentioned aspects that should be explored regarding this tool will be underlined., (Copyright © 2021 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.)

Purpose: Several factors affect the accuracy of non-invasive continuous hemoglobin concentration (SpHb) measurements. We had previously shown an increase in the perfusion index (PI) following induction of anesthesia which was associated with an increase in the difference between SpHb and total hemoglobin (tHb) (SpHb-tHb). We hypothesized that blunting the increase in PI by maintaining blood pressure during induction of anesthesia would improve the agreement between SpHb and tHb measurements., Methods: Twenty-nine adult patients were enrolled. Patients were randomly assigned by use of sequentially numbered, opaque sealed envelopes to a control (group C) or a phenylephrine group (group P). Anesthesia was induced and maintained with propofol, remifentanil, and ketamine. In group P, phenylephrine was infused at 0.5 µg/kg/min during induction of anesthesia. SpHb and PI were monitored with a Radical-7 Pulse CO-Oximeter. tHb and hematocrit were measured with the ABL800 blood gas analyzer., Results: Following induction of anesthesia, PI increased significantly in both groups (p < 0.001 and p < 0.05 in groups C and P, respectively). However, the increase in PI was significantly smaller in group P than in group C (2.6 ± 1.3 vs 0.8 ± 1.4%, p < 0.001). Similarly, the change in SpHb-tHb was significantly smaller in group P than in group C (0.40 ± 0.78 vs 0.97 ± 0.70 g/dl, p < 0.05). Changes in SpHb-tHb are correlated with changes in PI (r = 0.46, p < 0.05)., Conclusions: The findings suggest that blunting the increase in PI by maintaining arterial pressure during induction of anesthesia improves the agreement between SpHb and tHb values.

The IKORUS system (Vygon, Écouen, France) allows continuous monitoring of the urethral perfusion index (uPI) using a photoplethysmographic sensor mounted near the base of the balloon of a dedicated urinary catheter. We aimed to test the hypothesis that the uPI decreases during off-pump coronary artery bypass (OPCAB) surgery and to investigate the relationship between the uPI and macrocirculatory variables. Prospective observational study. University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Twenty patients having OPCAB surgery. None. The primary endpoint was changes in the uPI during OPCAB surgery. We additionally investigated associations between the uPI and cardiac output, mean arterial pressure, heart rate, and point-of-care variables. Twenty patients with 24,137 uPI measurements were included. Overall, there was a high interindividual variability in the uPI. Compared with the preparation phase (during which the median [interquartile range] uPI was 7.7 [5.6-12.0]), the uPI decreased by 14% (95% CI 13%-15%) during the bypass grafting phase, by 35% (95% CI 34%-36%) during the cardiac positioning phase, and by 7% (95% CI 6%-9%) during hemostasis. There was no clinically important association between uPI and either cardiac output, mean arterial pressure, or heart rate. The uPI decreases during OPCAB surgery, specifically during the cardiac positioning phase. There was no clinically important association between uPI and either cardiac output, mean arterial pressure, or heart rate. It, therefore, remains to be determined whether intraoperative uPI decreases are clinically important, reflect alterations in intra-abdominal tissue perfusion that are not reflected by systemic macrohemodynamics, and can help clinicians guide therapeutic interventions. [ABSTRACT FROM AUTHOR]

ABSTRACTBackground The most common drawback of spinal anesthesia (SA) is hypotension, which has adverse effects on both mother and fetus; consequently, early detection and management of spinal hypotension have been considered a very important topic in obstetric anesthesia. Additionally, the capability to ultimately diagnose hypotension could permit initiation of adequate treatment. The standard method to estimate blood pressure during cesarean section is noninvasive blood pressure measurement. However, periods of hypotension could be missed within a reasonable time frame.Methods Perfusion index (PI) and blood pressure were measured in 100 pregnant women during elective cesarean section under SA.Results PI had a significant negative correlation with the change occurred in systolic blood pressure (SBP) (r = −.432, p

Background: Whether peripheral vasodilation or decrease in cardiac output causes the reduction in blood pressure (BP) following induction of anaesthesia, is not clearly understood. Therefore, an attempt was made to elucidate the mechanism of hypotension in terms of change in perfusion index (PI) and cardiac output. Methods: With institutional ethics committee permission and consent, 66 patients were assigned equally to three groups. Each group received a titrated dose of a different induction agent, namely thiopentone (5 mg/kg), propofol (2 mg/kg) or etomidate (0.3 mg/kg). PI, heart rate (HR), and systolic, diastolic and mean arterial pressure were recorded at baseline and then every minute until 10 minutes post intubation. Echocardiography parameters (i.e. ejection fraction (EF), contractility and left ventricular end diastolic volume (LVEDV)) were measured at baseline, three minutes post induction and five minutes post intubation. Statistical analysis included one-way analysis of variance (ANOVA), Bonferroni test or Kruskal Wallis/Mann Whitney-U test. Results: The EF and contractility remained stable after induction with all three induction agents. However, LVEDV and hence stroke volume increased significantly with etomidate (p = 0.011). There was gradual and continued increase in PI and reduction in the BP from the time of induction, which was minimal with etomidate and maximum with propofol. A marginal increase in HR was seen with thiopentone, while others caused a steady fall. Conclusion: Vasodilation and reduced HR were responsible for the hypotension following induction of anaesthesia by intravenous agents. The effect was maximal with propofol with no evidence of myocardial depression. Etomidate lead to increase in stroke volume which explains its cardiovascular stability [ABSTRACT FROM AUTHOR]

Background: The most common drawback of spinal anesthesia (SA) is hypotension, which has adverse effects on both mother and fetus; consequently, early detection and management of spinal hypotension have been considered a very important topic in obstetric anesthesia. Additionally, the capability to ultimately diagnose hypotension could permit initiation of adequate treatment. The standard method to estimate blood pressure during cesarean section is noninvasive blood pressure measurement. However, periods of hypotension could be missed within a reasonable time frame. Methods: Perfusion index (PI) and blood pressure were measured in 100 pregnant women during elective cesarean section under SA. Results: PI had a significant negative correlation with the change occurred in systolic blood pressure (SBP) (r = -.432, p < .0001); by using univariate linear regression analysis, the PI explains 20.2% of variability in SBP as PI significantly predicts the change occurred in SBP (F = 24.8, p < .0001), as each one unit increase in PI, accompanied by a significant decrease in SBP by 2.089 (mm/hg), as (b, t, p) (-2.089, -4.987, .0001), respectively. There was a significant difference in SBP and PI before and after giving oxytocin bolus [(z = -1.9, P = .05) and (z = -4.3, P < .0001), respectively]. By comparing PI before vs. after taking ephedrine bolus, there was a significant decrease in median of PI [median of PI before 10 (5.5-15) vs. median of PI after 7.5 (6-15.5) (z = -6.6, P < .0001)]. Discussion: After SA with sympathetic blockade, peripheral vascular tone declined and therefore PI increased. Conclusion: PI could anticipate the incidence of hypotension during cesarean delivery with SA. Ephedrine effect could be evaluated rapidly by the alteration in the PI so that further need can be judged. Oxytocin has a significant impact on vascular tone with 5 international unit bolus, although it does not have a significant effect on blood pressure. [ABSTRACT FROM AUTHOR]

Clinical utility of perfusion index (PI) has entered a new realm as a non-invasive, quantitative index of stress response to endotracheal intubation. Transoral robotic surgery (TORS) involves F-K retractor aided docking of the surgical robot producing haemodynamic and stress responses akin to laryngoscopy. We compared the stress response to videolaryngoscopy with that due to docking of da Vinci surgical robot using PI, heart rate and mean arterial pressure evaluated at specific time points post-laryngoscopy and post-docking. Twenty-six adult patients, scheduled for TORS under general endotracheal anaesthesia were included in this prospective, observational, single-centric cohort study. Statistical analysis included paired samples t-test, dotted box-whisker plots, trendlines and correlograms for comparative analysis of two stressors, laryngoscopy and docking. Baseline PI was 4.14. PI values increased post-midazolam (4.23), 1 min (5.69) and 3 min (6.25) post anaesthetic-induction, plummeted at laryngoscopy (3.24), remained low at 1 min (3.68), 3 min (4.69) thereafter, and were highest at 10 min (6.17) post-laryngoscopy and predocking (6.84). Docking witnessed a fall in PI (4.1), which remained low at 1 min (4.02), 3 min (4.31) and 10 min (4.79) post-docking. PI was significantly higher at laryngoscopy compared with PI at docking (p = 0.0044). At 1 min and 3 min post-laryngoscopy and post-docking, respectively, the differences in PI were statistically insignificant. PI at 10 min post-laryngoscopy was significantly lower than PI at 10 min post-docking (p < 0.0001). As non-invasively quantified by PI, videolaryngoscopic stress response is more intense but shorter-lived versus that due to docking. PI displays a negative correlation with haemodynamic variables. PI at laryngoscopy is a good predictor of PI at docking, enabling pre-emptive measures (fentanyl bolus; deepening of volatile anaesthesia from MAC-maintenance to MAC-intubation) anticipating the docking-induced stress response. Trial registrationhttp://ctri.nic.in; Identifier: CTRI/2019/11/022091. [ABSTRACT FROM AUTHOR]

Background: Supraclavicular brachial plexus blocks (SCBPB) are routinely placed prior to anaesthetic induction for post-operative pain relief after prolonged orthopaedic oncosurgery, since patients are required to remain awake for sensorimotor evaluation of block. If the window period after surgery but before anesthesia-reversal is employed for administering SCBPB, it bestows the quadruple advantage of being painless, not augmenting surgical bleed, longer post-operative analgesia and reduced opioid-related side effects. The problem spot is assessing SCBPB-efficacy under general anesthesia. Methods: This prospective, single-centric, observational cohort study included 30 patients undergoing upper limb orthopaedic oncosurgery under general anesthesia. Perfusion index (PI) was assessed using two separate units of Radical-7™ finger pulse co-oximetry devices simultaneously in both the upper limbs and PI ratios calculated. Skin temperature was noted. Results: After successful block, PI values in blocked limb suddenly increased after 5 min, progressively increasing for next 10 min, whereas PI failed to increase further above that attained post anaesthetic-induction in unblocked limb. PI values in the blocked limb were 4.32, 4.49, 4.95, 7.25, 7.71, 7.90, 7.94, 7.89, and 7.93 at 0, 2, 3, 5, 10, and 15 min post block-institution at reversal and 2 min, 5 min post-reversal, respectively. PI ratios at 2, 3, 5, 10, and 15 min post block-administration in the blocked limb, taking PI at local anaesthetic injection as denominator were 1.04, 1.15, 1.67, 1.78, and 1.83, respectively. Correlation between PI and skin temperature in the blocked limb gave a repeated measures correlation coefficient of 0.79. Conclusion: Monitoring trends in PI and PI-ratio in the blocked limb is a quantitative, non-invasive, inexpensive, simple, effective technique to monitor SCBPB-onset in anaesthetised patients.

Abstract Background Pulse perfusion index (PI) reflects blood perfusion. It has been reported that PI can be used to evaluate the effect of nerve block, but currently, it is mainly focused on awake adults. In pediatric general anesthesia, it has been reported that PI can evaluate the effect of the sacral block. Still, there is a lack of relevant research on the impact of brachial plexus blocks. Our objective is to assess the prediction effects of PI on the success of supraclavicular brachial plexus block in pediatric patients under sevoflurane or propofol general anesthesia. Methods/design This is a mono-center, parallel, 2-arm randomized superiority trial. One hundred four children aged 1 month to 12 years who undergo upper limb surgery will be enrolled in this study. According to anesthesia induction and maintenance medication, they will be divided into sevoflurane and propofol groups. The PI values of the index and little finger will be recorded on the blocked and non-blocked sides of supraclavicular brachial plexus block (SCB) in all children. The primary outcome is to assess the effects of PI on the success of supraclavicular brachial plexus block in pediatric patients under sevoflurane or propofol general anesthesia. The secondary outcome includes mean arterial blood pressure (MAP), heart rate (HR), and correlation between baseline PI and 10 min after SCB (PI ratio). Discussion This trial will provide evidence on the changes in PI after SCB in sevoflurane or propofol anesthesia in children. SCB may lead to changes in PI values under sevoflurane or propofol anesthesia. After the children wake up at the end of the surgery, the changes in PI values on the block side and non-block side may be helpful to judge the effect of nerve block when excluding the influence of anesthetics. Trial registration ClinicalTrials.gov NCT04216823 . Registered on 15 July 2020.

Objective: Perfusion index has shown to be helpful in the operative and critical care settings to monitor peripheral tissue perfusion. Randomised controlled trials quantifying different agents' vasodilatory properties using perfusion index has been limited. Therefore, we undertook this study to compare the vasodilatory effects of isoflurane and sevoflurane using perfusion index. Methods: This is a pre-specified sub-analysis of a prospective randomised controlled trial on the effects of inhalational agents at equipotent concentration. We randomly allocated patients scheduled for lumbar spine surgery to either isoflurane or sevoflurane groups. We recorded values of perfusion index at age-corrected 1 Minimum Alveolar Concentration (MAC) concentration at baseline, pre- and post-application of a noxious stimulus. The primary outcome of interest was the measure of vasomotor tone with perfusion index, and the secondary outcomes which were analysed were mean arterial pressure and heart rate. Results: At age-corrected 1.0 MAC, there was no significant difference in the pre-stimulus haemodynamic variables and perfusion index between both groups. During the post-stimulus period, there was a significant increase in heart rate in the isoflurane group compared to the sevoflurane group, with no significant difference in the mean arterial pressure values between both groups. Though the perfusion index decreased during the post-stimulus period in both groups, there was no statistically significant difference between the 2 groups (P = .526, repeated-measures analysis of variance). Conclusion: In a steady state of age-corrected 1.0 MAC, isoflurane and sevoflurane had a similar perfusion index before and after a standardised nociceptive stimulus, which suggests that both of these agents have similar effect on peripheral perfusion and vasomotor tone. [ABSTRACT FROM AUTHOR]

Background: Supraclavicular brachial plexus blocks (SCBPB) are routinely placed prior to anaesthetic induction for post-operative pain relief after prolonged orthopaedic oncosurgery, since patients are required to remain awake for sensorimotor evaluation of block. If the window period after surgery but before anesthesia-reversal is employed for administering SCBPB, it bestows the quadruple advantage of being painless, not augmenting surgical bleed, longer post-operative analgesia and reduced opioid-related side effects. The problem spot is assessing SCBPB-efficacy under general anesthesia. Methods: This prospective, single-centric, observational cohort study included 30 patients undergoing upper limb orthopaedic oncosurgery under general anesthesia. Perfusion index (PI) was assessed using two separate units of Radical-7™ finger pulse co-oximetry devices simultaneously in both the upper limbs and PI ratios calculated. Skin temperature was noted. Results: After successful block, PI values in blocked limb suddenly increased after 5 min, progressively increasing for next 10 min, whereas PI failed to increase further above that attained post anaesthetic-induction in unblocked limb. PI values in the blocked limb were 4.32, 4.49, 4.95, 7.25, 7.71, 7.90, 7.94, 7.89, and 7.93 at 0, 2, 3, 5, 10, and 15 min post block-institution at reversal and 2 min, 5 min post-reversal, respectively. PI ratios at 2, 3, 5, 10, and 15 min post block-administration in the blocked limb, taking PI at local anaesthetic injection as denominator were 1.04, 1.15, 1.67, 1.78, and 1.83, respectively. Correlation between PI and skin temperature in the blocked limb gave a repeated measures correlation coefficient of 0.79. Conclusion: Monitoring trends in PI and PI-ratio in the blocked limb is a quantitative, non-invasive, inexpensive, simple, effective technique to monitor SCBPB-onset in anaesthetised patients. [ABSTRACT FROM AUTHOR]

Patients with hypertension develop hemodynamic instability more frequently during anesthesia—particularly post-induction. Therefore, different monitoring methods may be required in patients with hypertension. Perfusion index—the ratio of the pulsatile blood flow to the non-pulsatile static blood flow in a patient's peripheral tissues, such as the fingers or ears—can show the hemodynamic status of the patient in a non-invasive way. Among the sites used for measuring the perfusion index, it is assumed that the ear is more reliable than the finger for hemodynamic monitoring, because proximity to the brain ensures appropriate perfusion. We hypothesized that the low value of preoperative ear PI could be a predictor of post-induction hypotension in patients with hypertension. Thirty patients with hypertension were enrolled. The perfusion index and pleth variability index were measured using the ear, finger, and blood pressure, and heart rate was recorded to monitor hypotension. After insertion of the supraglottic airway, 20 patients developed post-induction hypotension. Those who developed hypotension showed a significantly lower preoperative perfusion index of the ear. The preoperative perfusion index of the ear could predict post-induction hypotension in patients with hypertension. [ABSTRACT FROM AUTHOR]

Background: Pulse perfusion index (PI) reflects blood perfusion. It has been reported that PI can be used to evaluate the effect of nerve block, but currently, it is mainly focused on awake adults. In pediatric general anesthesia, it has been reported that PI can evaluate the effect of the sacral block. Still, there is a lack of relevant research on the impact of brachial plexus blocks. Our objective is to assess the prediction effects of PI on the success of supraclavicular brachial plexus block in pediatric patients under sevoflurane or propofol general anesthesia.Methods/design: This is a mono-center, parallel, 2-arm randomized superiority trial. One hundred four children aged 1 month to 12 years who undergo upper limb surgery will be enrolled in this study. According to anesthesia induction and maintenance medication, they will be divided into sevoflurane and propofol groups. The PI values of the index and little finger will be recorded on the blocked and non-blocked sides of supraclavicular brachial plexus block (SCB) in all children. The primary outcome is to assess the effects of PI on the success of supraclavicular brachial plexus block in pediatric patients under sevoflurane or propofol general anesthesia. The secondary outcome includes mean arterial blood pressure (MAP), heart rate (HR), and correlation between baseline PI and 10 min after SCB (PI ratio).Discussion: This trial will provide evidence on the changes in PI after SCB in sevoflurane or propofol anesthesia in children. SCB may lead to changes in PI values under sevoflurane or propofol anesthesia. After the children wake up at the end of the surgery, the changes in PI values on the block side and non-block side may be helpful to judge the effect of nerve block when excluding the influence of anesthetics.Trial Registration: ClinicalTrials.gov NCT04216823 . Registered on 15 July 2020. [ABSTRACT FROM AUTHOR]

Background and Aims: Changes in the sympathetic nervous system by pain can impact smooth muscle tone and can alter perfusion. This can be monitored by perfusion index (PI). It is a non-invasive, indirect, and continuous measure of peripheral perfusion. This study investigates the changes in PI due to painful stimuli under general anaesthesia. Methods: Twenty patients between the ages of 20 and 45 years, with informed consent, who were undergoing elective laparoscopic procedure, and belonging to the American Society of Anesthesiologists (ASA) physical status class I were connected with standard monitors along with SEDLINE, pulse oximetry (Root, Masimo Corporation®, Irvine, CA, USA) to monitor PI and Pleth-Variability Index (PVi). General anaesthesia was administered. PI, PVi, heart rate (HR), and non-invasive blood pressure were recorded pre-induction, during induction, before and after intubation, at the time of pneumoperitoneum (P0), and first laparoscopic port insertion (P1). Later, intravenous injection of fentanyl 0.5 μg/kg was administered and values were recorded at the second (P2) and third (P3) port insertion. The aforementioned parameters were recorded for up to 30 minutes. Statistical confirmation was done through paired t tests. Results: PI values after fentanyl increased from 5.33 ± 2.67 (P1) to 5.99 ± 2.8 (P2) (P < 0.001), and to 6.3 ± 2.88 (P3) (P < 0.001). This increase correlated with a decrease in HR, from 101.42 ± 12.53 (P1) to 87.93 ± 10.98 (P2) (P < 0.001), and to 83 ± 10.82 (P3) (P < 0.001). Conclusion: PI can be a tool to monitor the nociception in anaesthetised patients when administering analgesia. [ABSTRACT FROM AUTHOR]

Introduction: Hypotension is a common complication after spinal anesthesia for cesarean delivery which is caused by sympathetic block 1. This can result in adverse maternal and fetal outcomes. Hence prevention and early treatment of spinal hypotension early has been a key research area in obstetric anesthesia. Intermittent non-invasive blood pressure measurement is the standard practice that fails to detect episodes of hypotension in a timely fashion. Methods: Noninvasive PI and blood pressure were measured in 109 healthy parturients undergoing elective cesarean section under spinal anesthesia. Results: PI appeared to increase significantly and more quickly in parturients with significant hypotension. Discussion: Findings may be due to the thoracic sympathetic blockade. Conclusion: Perfusion index can be a useful tool to early predict hypotension following spinal anesthesia for cesarean section. Response to ephedrine can be quickly assessed by the change in the PI which helps to decide on further boluses of ephedrine. Effect on the vascular tone by oxytocin is significant with 5IU bolus, though it does not cause a significant blood pressure drop.

Aim: We tested a hypothesis that postoperative active warming and/or arm leg stretches reduce the difference between core and skin temperatures (primary variable) improving the peripheral circulation immediately after major abdominal surgery. Methods: Fifty‐one patients undergoing major abdominal surgeries were randomly assigned to receive one of three interventions immediately after surgery; routine care (control group), mild intermittent exercise on the bed (exercise group), and forced‐air warming (warming group). Core and skin temperatures and perfusion index were continuously measured from anesthesia induction to 12 h after arrival at the ward. Results: Core body temperature was maintained over 37°C with a relatively greater gap between core and skin temperatures over 1°C and reduced perfusion index in the early postoperative period in the control group. In the warming group, the reduced skin temperature at arrival at the ward approximated to the core temperature leading to significant reduction of the temperature gap and increasing the perfusion index to the preoperative level. Although less evident, both the temperature gap and peripheral perfusion significantly improved in the exercise group after 6 and 8 h after arrival at the ward, respectively. Conclusions: Vasoconstriction in response to cessation after anesthesia and surgery serves to maintain core temperature, but impairs peripheral circulation. Active warming and intermittent mild exercise immediately after arrival at the ward reduces the temperature gap and improves peripheral circulation during the early postoperative period. While cost‐effectiveness needs to be considered before clinical application of the intervention, the cost‐free mild exercise may be a feasible option for improving postoperative patient care. [ABSTRACT FROM AUTHOR]

Introduction: Hypotension is a common complication after spinal anesthesia for cesarean delivery which is caused by sympathetic block 1. This can result in adverse maternal and fetal outcomes. Hence prevention and early treatment of spinal hypotension early has been a key research area in obstetric anesthesia. Intermittent non-invasive blood pressure measurement is the standard practice that fails to detect episodes of hypotension in a timely fashion. Methods: Noninvasive PI and blood pressure were measured in 109 healthy parturients undergoing elective cesarean section under spinal anesthesia. Results: PI appeared to increase significantly and more quickly in parturients with significant hypotension. Discussion: Findings may be due to the thoracic sympathetic blockade. Conclusion: Perfusion index can be a useful tool to early predict hypotension following spinal anesthesia for cesarean section. Response to ephedrine can be quickly assessed by the change in the PI which helps to decide on further boluses of ephedrine. Effect on the vascular tone by oxytocin is significant with 5IU bolus, though it does not cause a significant blood pressure drop. [ABSTRACT FROM AUTHOR]

Background: During general anaesthesia, intraoperative hypotension (IOH), defined as a mean arterial pressure (MAP) reduction of > 20%, is frequent and may lead to complications. Pulse oximetry is mandatory in the operating room, making the photoplethysmographic signal and parameters, such as relative dicrotic notch height (Dicpleth) or perfusion index (PI), readily available. The purpose of this study was to investigate whether relative variations of Dicpleth and PI could detect IOH during anaesthesia induction, and to follow their variations during vasopressor boluses.Methods: MAP, Dicpleth, and PI were monitored at 1-min intervals during target control induction of anaesthesia with propofol and remifentanil in 61 subjects. Vasopressor infusion (norepinephrine or phenylephrine) was performed when hypotension occurred according to the decision of the physician.Results: The delta in Dicpleth and PI accurately detected IOH, with areas under the receiver operating characteristic curves (AUC) of 0.86 and 0.83, respectively. The optimal thresholds were -19% (sensitivity 79%; specificity 84%) and 51% (sensitivity 82%; specificity 74%) for ΔDicpleth and ΔPI, respectively. There was no difference between the ROC of ΔDicpleth and ΔPI (P=0.22). Combining both ΔDicpleth and ΔPI further improved the hypotension detection power (AUC=0.91) with a sensitivity and specificity of 84%. MAP variations were correlated with ΔDicpleth and ΔPI during vasopressor infusion (r=0.73 and -0.62, respectively; P<0.001).Conclusions: The relative variation in Dicpleth and PI derived from the photoplethysmographic signal can be used as a non invasive, continuous, and simple tool to detect intraoperative hypotension, and to track the vascular response to vasoconstrictor drugs during induction of general anaesthesia.Clinical Trial Registration: NCT03756935. [ABSTRACT FROM AUTHOR]

Background and Aims: Hypotension during propofol induction is a common problem. Perfusion index (PI), an indicator of systemic vascular resistance, is said to be predictive of hypotension following subarachnoid block. We hypothesised that PI can predict hypotension following propofol induction and a cut-off value beyond which hypotension is more common can be determined. Methods: Fifty adults belonging to the American Society of Anesthesiologists' physical status I/II undergoing elective surgery under general anaesthesia were enrolled for this prospective, observational study. PI, heart rate, blood pressure (BP) and oxygen saturation were recorded every minute from baseline to 10 min following induction of anaesthesia with a titrated dose of propofol, and after endotracheal intubation. Hypotension was defined as fall in systolic BP (SBP) by >30% of baseline or mean arterial pressure (MAP) to <60 mm Hg. Severe hypotension (MAP of <55 mm Hg) was treated. Results: Within first 5-min after induction, the incidence of hypotension with SBP and MAP criteria was 30% and 42%, respectively, and that of severe hypotension, 22%. Baseline PI <1.05 predicted incidence of hypotension at 5 min with sensitivity 93%, specificity 71%, positive predictive value (PPV) 68% and negative predictive value (NPV) 98%. The area under the ROC curve (AUC) was 0.816, 95% confidence interval (0.699-0.933), P < 0.001 Conclusion: Perfusion index could predict hypotension following propofol induction, especially before endotracheal intubation, and had a very high negative predictive value. [ABSTRACT FROM AUTHOR]

Background and Aims: Perfusion index (PI) is a new parameter tried for predicting hypotension during spinal anaesthesia for the lower segment caesarean section (LSCS). This study aimed at investigating the correlation between baseline perfusion index and incidence of hypotension following SAB in LSCS. Methods: In this prospective observational study, 126 parturients were divided into two groups on the basis of baseline PI. Group I included parturients with PI of ≤3.5 and Group II, parturients with PI values >3.5. Spinal anaesthesia was performed with 10 mg of injection bupivacaine 0.5% (hyperbaric) at L3-L4 or L2-L3 interspace. Hypotension was defined as mean arterial pressure <65 mmHg. Statistical analysis was performed using Chi-square test, independent sample t-test and Mann-Whitney U-test. Regression analysis with Spearman's rank correlation coefficient was done to assess the correlation between baseline PI and hypotension. Receiver operating characteristic (ROC) curve was plotted for PI and occurrence of hypotension. Results: The incidence of hypotension in Group I was 10.5% compared to 71.42% in Group II (P < 0.001). There was significant correlation between baseline PI >3.5 and number of episodes of hypotension (rs 0.416, P < 0.001) and total dose of ephedrine (rs 0.567, P < 0.001). The sensitivity and specificity of baseline PI of 3.5 to predict hypotension was 69.84% and 89.29%, respectively. The area under the ROC curve for PI to predict hypotension was 0.848. Conclusion: Baseline perfusion index >3.5 is associated with a higher incidence of hypotension following spinal anesthesia in elective LSCS. [ABSTRACT FROM AUTHOR]