Surgical Plethysmographic Index Research Articles

Investigation of efficacy of erector spinae plane block administered in different volumes on intraoperative opioid consumption and postoperative analgesia in breast surgery: Randomized, prospective, double-blind study.

We investigated the efficacy of the erector spinae plane block, which has been proven to be effective in breast surgery, on intraoperative opioid consumption and postoperative analgesia when administered in different volumes with the same concentration of local anesthetic. This study is designed as randomized, prospective, and double-blind. Seventy patients aged between 18-70 years, undergoing ASA I-III elective breast surgery, were included. Unilateral erector spinae plane block was achieved by administering 20 mL of 0.375% bupivacaine hydrochloride in 35 patients in Group I and 30 mL of 0.375% bupivacaine hydrochloride in 35 patients in Group II. The analgesic requirement of the patients was monitored with the surgical plethysmographic index throughout the surgery. Intraoperative and postoperative opioid consumption, rescue analgesic requirements in the first 24 hours, and NRS scores at the 10th minute, 1st hour, 6th hour, 12th hour, and 24th hour postoperatively were recorded. Both intraoperative and postoperative opioid consumptions were similar between groups (p>0.05). The number of involved dermatomes was significantly higher in Group II (p<0.05). No significant difference was found between postoperative NRS scores (p>0.05). In elective breast surgery, erector spinae plane block administered at the same concentration in 20 or 30 mL volumes does not make a difference in opioid consumption and postoperative analgesia.

Schnider and Eleveld Models for Propofol Target-Controlled Infusion Anesthesia: A Clinical Comparison.

Various pharmacokinetic/pharmacodynamic (PK/PD) models have been developed to accurately dose propofol administration during total intravenous anesthesia with target-controlled infusion (TIVA-TCI). We aim to clinically compare the performance of the Schnider model and the new and general-purpose Eleveld PK/PD model during TIVA-TCI. We conducted a prospective observational study at a single center, enrolling 78 female patients, including 37 adults (aged < 65 years) and 41 elderly patients (aged ≥ 65 years). These patients underwent breast surgery with propofol-remifentanil TIVA-TCI guided by the bispectral index (BIS) for depth of anesthesia monitoring (target value 40-60) and the surgical plethysmographic index (SPI) for antinociception monitoring (target value 20-50) without neuromuscular blockade. The concentration at the effect site of propofol (CeP) at loss of responsiveness (LoR) during anesthesia maintenance (MA) and at return of responsiveness (RoR), the duration of surgery and anesthesia (min), the time to RoR (min), the propofol total dose (mg), the deepening of anesthesia events (DAEs), burst suppression events (BSEs), light anesthesia events (LAEs) and unwanted spontaneous responsiveness events (USREs) were considered to compare the two PK/PD models. Patients undergoing BIS-SPI-guided TIVA-TCI with the Eleveld PK/PD model showed a lower CeP at LoR (1.7 (1.36-2.25) vs. 3.60 (3.00-4.18) μg/mL, p < 0.001), higher CePMA (2.80 (2.55-3.40) vs. 2.30 (1.80-2.50) μg/mL, p < 0.001) and at RoR (1.48 (1.08-1.80) vs. 0.64 (0.55-0.81) μg/mL, p < 0.001) than with the Schnider PK/PD model. Anesthetic hysteresis was observed only in the Schnider PK/PD model group (p < 0.001). DAEs (69.2% vs. 30.8%, p = 0.001) and BSEs (28.2% vs. 5.1%, p = 0.013) were more frequent with the Eleveld PK/PD model than with the Schnider PK/PD model in the general patient population. DAEs (63.2% vs. 27.3%, p = 0.030) and BSEs (31.6% vs. 4.5%, p = 0.036) were more frequent with the Eleveld PK/PD model than with the Schnider PK/PD model in the elderly. The Schnider and Eleveld PK/PD models impact CePs differently. A greater incidence of DAEs and BSEs in the elderly suggests more attention is necessary in this group of patients undergoing BIS-SPI-guided TIVA-TCI with the Eleveld PK/PD than with the Schnider model.

Intraoperative analgesic requirement using surgical plethysmographic index guidance in lumbar spine surgeries: A comparative study

Intraoperative analgesic requirement using surgical plethysmographic index guidance in lumbar spine surgeries: A comparative study

Does surgical plethysmographic index-guided analgesia affect opioid requirement and extubation time? A systematic review and meta-analysis

PurposeThis meta-analysis of all relevant clinical trials investigated surgical plethysmographic index (SPI)-guided analgesia’s efficacy under general anesthesia for perioperative opioid requirement and emergence time after anesthesia.MethodsPubMed, Embase, Web of Science, and Cochrane Library were searched up to January 2022 to identify clinical trials comparing SPI-guided and conventional clinical practice for patients who underwent general anesthesia. With the random-effects model, we compared intraoperative opioid consumption, emergence time, postoperative pain, analgesia requirement, and incidence of postoperative nausea and vomiting (PONV).ResultsThirteen randomized controlled trials (RCTs) (n = 1314) met our selection criteria. The overall pooled effect sizes of all RCTs indicated that SPI-guided analgesia could not significantly reduce opioid consumption during general anesthesia. SPI-guided analgesia accompanied with hypnosis monitoring could decrease intraoperative opioid consumption (standardized mean difference [SMD] − 0.31, 95% confidence interval [CI] − 0.63 to 0.00) more effectively than SPI without hypnosis monitoring (SMD 1.03, 95% CI 0.53–1.53), showing a significant difference (p < 0.001). SPI-guided analgesia could significantly shorten the emergence time, whether assessed by extubation time (SMD − 0.36, 95% CI − 0.70 to − 0.03, p < 0.05, I2 = 67%) or eye-opening time (SMD − 0.40, 95% CI − 0.63 to − 0.18, p < 0.001, I2 = 54%). SPI-guided analgesia did not affect the incidence of PONV, postoperative pain, and analgesia management.ConclusionSPI-guided analgesia under general anesthesia could enhance recovery after surgery without increasing the postoperative complication risk. However, it did not affect intraoperative opioid requirement. Notably, SPI-guided analgesia with hypnosis monitoring could effectively reduce intraoperative opioid requirement.

On possibility of application of instrumental and projection assessment of pain syndrome

Topicality. In modern medical practice, the issue of studying and developing methods for assessing pain syndrome is acute, which is associated not only with the complexity of interpreting this sensation, but also with the lack of a unified idea of the mechanism for forming pain sensations. The development of diagnostic capabilities in the field of medical practice and the possibility of widespread use of modern equipment allowed us to take a new look at the possibility of instrumental and projection assessment of pain syndrome.The purpose of this study is to study the possibility of using instrumental and projection assessment of pain syndrome in medical practice.Material and methods. The study was carried out on the basis of a compilation of data from modern domestic and foreign scientific sources in the field of the possibility of using instrumental and projection assessment of pain syndrome.Results. The latest methods of assessing pain syndrome are aimed at the maximum possible objectification of pain sensations, which allows making the most reliable clinical assessment of the patient's condition. Currently, research methods such as neuroimaging, determination of cutaneous electroconductivity, analgesic nociceptive index, surgical plethysmographic index, electroencephalography, plethysmography are being actively introduced. The instrumental methods described above are the latest methods for objectively assessing not only the intensity of pain syndrome, but also the degree of nociceptive protection when applying intraoperative analgesia methods. The ambiguity of the results obtained during clinical trials as part of the evaluation of the validity of these criteria for assessing the strength of nociception dictates the need to continue further research in the field of this issue.Conclusion. In modern medical practice, the issue of developing methods to ensure an adequate, objective assessment of the intensity of pain syndrome remains acute. This issue mainly concerns surgical doctors, which is associated with the need to provide an adequate anesthesiological allowance in the intraoperative period, which will avoid the development of postoperative pain syndrome. Solving this problem will contribute to a significant improvement in the results of therapeutic interventions and reduce the risk of developing chronic pain in the patient.

Use of Surgical Plethysmographic Index to Assess the Effect of Dexmedetomidine on Hemodynamic Response to Intubation and Surgical Stress

Use of Surgical Plethysmographic Index to Assess the Effect of Dexmedetomidine on Hemodynamic Response to Intubation and Surgical Stress

Evaluation of Surgical Pleth Index and Analgesia Nociception Index as surrogate pain measures in conscious postoperative patients: an observational study.

We evaluated the performance of the Surgical Plethysmographic Index (SPI) and the Analgesia Nociception Index (ANI) as surrogate pain measures and determined their respective cut-off values for detecting pain in conscious postoperative patients. In total, 192 patients after elective surgery were enrolled. Baseline SPI and ANI data were acquired for 10min in the operating room prior to surgery when the patients rated their pain as 0 on the numerical rating scale (NRS). Upon arrival in the post-anaesthesia care unit (PACU) after surgery, SPI and ANI data were recorded for 10min. The means of the recorded data at OR and PACU were defined as the values representing baseline and postoperative pain, respectively. SPI and ANI data obtained from 189 patients were analysed, who were anesthetized with propofol (n = 149) or sevoflurane (n = 40). Remifentanil was continuously infused intraoperatively in all patients. The values of SPI and ANI were significantly different in conscious patients without (NRS = 0) and with pain (NRS > 0). The areas under the receiver operating curves for SPI and ANI were 0.73 (P < 0.0001) and 0.67 (P < 0.0001), respectively. The cut-off values for SPI and ANI in predicting postoperative pain were 44 (sensitivity: 84%, specificity: 53%) and 63 (sensitivity: 52%, specificity: 82%), respectively, which are different from those suggested by their respective manufacturers for use in intraoperative state under general anaesthesia. The cut-off values of SPI and ANI for detecting pain were similar regardless of the type of anesthesia.

Standardised noxious stimulation-guided individual adjustment of remifentanil target-controlled infusion to prevent haemodynamic responses to laryngoscopy and surgical incision: A randomised controlled trial.

The surgical plethysmographic index (SPI) is one of the available indexes of the nociception-antinociception (NAN) balance. Individually adjusting the NAN balance to prevent somatic responses to noxious stimulation remains a challenge. To assess whether guiding remifentanil administration according to the SPI response to a calibrated noxious stimulus (NANCAL) can blunt the haemodynamic response to tracheal intubation and surgical incision. Randomised multicentre study. Two Belgian university hospitals from January 2014 to April 2015. After ethic review board approval and informed consent, 48 American Society of Anesthesiologists I or II adult patients scheduled for surgery under general anaesthesia were enrolled. Patients were randomly assigned to a SPI group, where remifentanil effect-site concentration was adjusted according to NANCAL, or a control group, where it was fixed at 4 ng ml. Propofol concentration was always adjusted to maintain the bispectral index close to 40. NANCAL consisted of a 100 Hz, 60 mA electrical tetanic stimulation during 30 s at the wrist before tracheal intubation and before surgical incision. The primary endpoint was the efficacy of the NANCAL-guided remifentanil administration to prevent the haemodynamic response to tracheal intubation and surgical incision. The secondary aim was to compare the ability of SPI, analgesia nociception index, pupil diameter and mean arterial pressure response to NANCAL to predict the haemodynamic response to tracheal intubation and surgical incision. Our SPI response to NANCAL-based correcting scheme for remifentanil administration was not superior to a fixed remifentanil concentration at blunting the haemodynamic response to tracheal intubation or surgical incision. Among all tested NAN balance indices, only mean arterial pressure had significant predictive ability with regard to the haemodynamic response to surgical incision. Further research is needed to define the best NANCAL stimulus and the best remifentanil correcting scheme to help individualised tailoring of antinociception for each specific subpopulation of surgical patients. Clinicaltrials.gov NCT: 02884310; https://clinicaltrials.gov/ct2/show/NCT02884310.

Monitoring of surgical plethysmographic index as a tool for monitoring the adequancy of antinociceptive protection during general anesthesia

Objective — to execute verification research of the importance of monitoring of a surgical plethysmographic index (SPI) when carrying out the general combined anesthesia with use of the automated control of concentration of anesthetic.Materials and Methods. In a prospective study there were 112 patients included operated for the pathology of the spine and the spinal cord of varying severity, extent and localization. The estimation of the ratio of numerical values of SPI, the level of stress hormone (ACTH, cortisol), the standard hemodynamic measures of the low-flow anesthesia with Et-control using the extended (due to entropy and SPI) monitoring.Results. Monitoring the adequacy of antinociceptive protection based on the performance of surgical plethysmographic index (SPI) allows detection of nociceptive responses to an earlier stage.Conclusion. The study revealed that the use of SPI monitoring the operations of high-risk permits anesthesia, with optimum concentration of opioids required, and minimal hemodynamic response of the patient.

Influence of gravitational sympathetic stimulation on the Surgical Plethysmographic Index.

Surgical Plethysmographic Index (SPI), calculated from pulse photo-plethysmographic amplitude oscillations, has been proposed as a tool to measure nociception anti-nociception balance during general anesthesia, but it is affected by several confounding factor that alter the autonomic nervous system (ANS) modulation. We hypothesized that SPI may be mainly affected by sympathetic stimulation independently from nociception. We studied the effects of two sympathetic stimuli on SPI, delivered through passive head-up tilt at 45 and 90 degrees angles, in nine awake healthy adults. The sympathetic modulation was assessed by means of heart rate variability (HRV) analysis. Mean (SD) SPI significantly increased from baseline to 45 degrees [from 38.6 (13.7) to 60.8 (7.6), p<0.001)] and to 90 degrees angle tilt [82.3 (5.4), p<0.001]. The electrocardiographic mean R-to-R interval significantly shortened during both passive tilts, whereas systolic arterial pressure did not change during the study protocol. HRV changed significantly during the study protocol towards a predominance of sympathetic modulation during passive tilt. Gravitational sympathetic stimulation at two increasing angles, in absence of any painful stimuli, affects SPI in awake healthy volunteers. SPI seems to reflect the sympathetic outflow directed to peripheral vessels.

Is the surgical plethysmographic index (SPI) measuring the nociception-anti-nociception balance during anaesthesia?

Is the surgical plethysmographic index (SPI) measuring the nociception-anti-nociception balance during anaesthesia?

Comparison of the Surgical Pleth Index with autonomic nervous system modulation on cardiac activity during general anaesthesia

Surgical plethysmographic index (SPI) has been proposed as a tool to measure the nociception/antinociception balance during general anaesthesia. Untreated nociception may increase sympathetic tone, but the relationship between SPI and the autonomic nervous system (ANS) is poorly understood. We hypothesised that two different levels of SPI might be associated with differences in ANS modulation, measured by the frequency domain analysis of heart rate variability (HRV). A randomised, cross-over group study, conducted between February and November 2009. University tertiary referral hospital in Milan, Italy. Forty-two adult patients undergoing scheduled laparoscopic abdominal surgery. ECG, noninvasive arterial blood pressure and SPI were recorded during balanced general anaesthesia with inhaled sevoflurane and intravenous remifentanil. After pneumoperitoneum induction, the remifentanil infusion rate was set to obtain two different levels of SPI (>50, HI-SPI, and <50, LO-SPI) for each patient. Arterial pressure, heart rate (HR), low-frequency and high-frequency spectral components, the low frequency/high frequency ratio (measure of sympathovagal balance) and whole power spectrum density of HRV were measured at the two different levels of SPI. Thirty-nine patients were included in the final analysis. During LO-SPI, HR and systolic and mean blood pressures were significantly lower than HI-SPI. The median low frequency/high frequency ratio was reduced during LO-SPI [1.29 interquartile range (IQR) 0.66 to 2.05) vs. 2.36 (1.30 to 3.62), P = 0.008]. The sensitivity analysis revealed a significant correlation between SPI changes and changes of all ANS indices, arterial pressure and HR, with a slightly better correlation for low frequency/high frequency (Spearman ρ = 0.70, IQR 0.484 to 0.834, P < 0.001). In the context of a balanced general anaesthesia in healthy patients undergoing laparoscopic abdominal surgery, ANS modulation seems to correlate with changes in SPI. Further studies are warranted to assess whether this may reflect a change in nociception/antinociception balance or a pharmacodynamic effect of remifentanil.