Effects of Thoracic Paravertebral Block on Nociceptive Levels After Skin Incision During Video-Assisted Thoracoscopic Surgery

Association between averaged intraoperative nociceptive response index and postoperative complications after lung resection surgery

OBJECTIVES

Since postoperative complications, defined as Clavien-Dindo grade ≥II, correlate with long-term survival after lung resection surgery in patients with primary lung cancer, identification of intraoperative risk factors for postoperative complications is crucial for better perioperative management. In the present study, we investigated the possible association between intraoperative variables for use in anaesthetic management and Clavien-Dindo grade ≥II.

METHODS

In this multi-institutional observational study, consecutive adult patients undergoing video-assisted thoracic surgery for primary lung cancer under general anaesthesia from March 2019 to April 2021 were enrolled. All patients were divided into 2 groups with Clavien-Dindo grade <II and ≥II. Uni- and multivariable analyses were performed to identify intraoperative risk factors.

RESULTS

After univariable analysis between patients with Clavien-Dindo grade <II (n = 415) and ≥II (n = 121), multivariable analysis revealed higher averaged nociceptive response (NR) index during surgery (mean NR), male sex, lower body mass index, longer duration of surgery, higher blood loss and lower urine volume, as independent risk factors for postoperative complications. In sensitivity analysis, based on the cut-off value of mean NR for postoperative complications, all patients were divided into high and low mean NR groups. The incidence of postoperative complications was significantly higher in patients with high mean NR (n = 332) than in patients with low mean NR (n = 204; P < 0.001).

CONCLUSIONS

Higher mean NR, as intraoperative variables for use in anaesthetic management, is associated with the higher incidence of postoperative complications after primary lung cancer surgery.

Quantitative evaluation of the effects of interscalene block on physiological responses to the balance between nociception and anti-nociception among inpatients undergoing total shoulder arthroplasty under general anesthesia

Although the suppression of physiological responses to the balance between nociception caused by surgical trauma and anti-nociception due to anesthesia during total shoulder arthroplasty (TSA) is relevant for better perioperative managements, quantitative evaluations of the effects of ultrasound-guided interscalene brachial plexus block (ISB) on physiological responses have not been performed. Physiological responses were assessed using the nociceptive response (NR) index. In this multi-institutional observational study, associations between ISB and NR values were examined among inpatients undergoing TSA under general anesthesia between March 2019 and January 2021. The effects of ISB on acute postoperative pain and major complications within 30 days after surgery were also examined. NR values after skin incision clearly showed significant suppressions of physiological responses in patients undergoing TSA with ISB (n = 60), compared to those without ISB (n = 24). Acute postoperative pain on the day of surgery was also significantly less in patients with ISB than in those without ISB. Postoperative complications, classified by Clavien-Dindo grades, showed no significant differences between patients with and without ISB. A propensity score-matched sensitivity analysis confirmed the same results in patients with (n = 21) and without ISB (n = 21). In conclusion, suppression of physiological responses to the balance between nociception and anti-nociception by ISB can be quantitatively evaluated by NR index during TSA.

[Nociception monitoring : Method for intraoperative opioid control?]

The intraoperative dosing of opioids is a challenge in routine anesthesia as the potential effects of intraoperative overdosing and underdosing are not completely understood. In recent years an increasing number of monitors were approved, which were developed for the detection of intraoperative nociception and therefore should enable a better control of opioid titration. The nociception monitoring devices use either continuous hemodynamic, galvanic or thermal biosignals reflecting the balance between parasympathetic and sympathetic activity, measure the pupil dilatation reflex or the nociceptive flexor reflex as a reflexive response to application of standardized nociceptive stimulation. This review article presents the currently available nociception monitors. Most of these monitoring devices detect nociceptive stimulations with higher sensitivity and specificity than changes in heart rate, blood pressure or sedation depth monitoring devices. There are only few studies on the effect of opioid titration guided by nociception monitoring and the possible postoperative benefits of these devices. All nociception monitoring techniques are subject to specific limitations either due to perioperative confounders (e.g. hypovolemia) or special accompanying medical conditions (e.g. muscle relaxation). There is an ongoing discussion about the clinical relevance of nociceptive stimulation in general anesthesia and the effect on patient outcome. Initial results for individual monitor systems show a reduction in opioid consumption and in postoperative pain level. Nevertheless, current evidence does not enable the routine use of nociception monitoring devices to be recommended as a clear beneficial effect on long-term outcome has not yet been proven.

Association between intraoperative nociception and surgical invasiveness in patients undergoing non-cardiac surgery under general anesthesia: a retrospective cohort study

There are several indexes of intraoperative nociception during surgery under general anesthesia. Although a higher degree of surgical invasiveness increases intraoperative nociception, an association between the index of intraoperative nociception and severity of surgical invasiveness has not been reported. We hypothesized that there is associations between averaged values of nociceptive response (NR) throughout surgery (mean NR), as the index of intraoperative nociception, and surgical severity codes in the Surgical outcome risk tool (SORT) or procedure risk codes in the Surgical mortality probability model (S-MPM). The primary outcome was the association between mean NR and severity scores of surgical procedure. Hence, a single institutional retrospective cohort study was performed in consecutive patients undergoing non-cardiac surgery under general anesthesia from June 2018 to May 2019. There were significant increases in the three categories of procedure risk in the S-MPM corresponding to the increase in mean NR values in 5090 patients. In the SORT, the highest intensity in the four categories of surgical severity also significantly correlated with the increase in mean NR values. Increasing intensity of intraoperative nociception is likely associated with higher severity codes of surgical invasiveness in prediction models for postoperative morbidity and mortality.

Preoperative Anxiety and Intraoperative Nociception in Patients Undergoing Thoracic Surgery

BACKGROUND

Preoperative anxiety is a common psychological state in cancer patients before surgery, inducing stress responses after surgery. Associations between preoperative anxiety and intraoperative nociception, however, have not been evaluated well. In the present study, we investigated the relationship in patients with lung cancer undergoing thoracic surgery.

MATERIALS AND METHODS

In this prospective study, 27 adult patients were enrolled. Intraoperative nociception during surgery was calculated as mean values of the nociceptive response (NR) throughout surgery. Associations between intraoperative nociception and preoperative patient characteristics including anxiety in addition to intraoperative variables were analyzed using univariate and multivariate regression analyses.

RESULTS

Multiple linear regression analysis revealed that mean NR values during surgery showed a negative correlation with preoperative anxiety (β = -0.353; P = 0.041) after adjustment for body mass index, depression, and total amount of fentanyl used during surgery. Body mass index was a confounder positively associated with mean NR during surgery.

CONCLUSIONS

Intraoperative nociception is likely associated with preoperative patient characteristics, having an inverse relationship with preoperative anxiety.

Prediction of early C-reactive protein levels after non-cardiac surgery under general anesthesia

Background

Early detection of postoperative increase in C-reactive protein (CRP) correlates with postoperative complications. The present study examined the association between preoperative / intraoperative factors and postoperative CRP levels, with development and validation of a prediction model of early postoperative CRP level, for prophylactic management of postoperative complications in patients undergoing surgery under general anesthesia.

Material and methods

Multivariate regression analysis was retrospectively performed to determine the independent factor of CRP levels on postoperative day (POD) 1 and to develop a prediction model. Validation of the prediction model was prospectively performed. Data from 316 adult patients on perioperative variables were retrospectively obtained in a training cohort in patients undergoing elective non-cardiac surgery. In a validation cohort, 88 patients undergoing mastectomy and 68 patients undergoing laparoscopic colon surgery were prospectively utilized to evaluate the value of the prediction model. Major complications after surgery were defined as the Clavien-Dindo grade IIIa or greater.

Results

Duration of surgery, mean nociceptive response (NR) during surgery as intraoperative nociception level, and preoperative CRP level were selected to set up the prediction model of CRP level on POD1 (P < 0.0001). In the validation cohort, the predicted CRP levels on POD1 significantly correlated with the measured CRP after mastectomy (P < 0.0001) and laparoscopic colon surgery (P = 0.0001). Receiver-operating characteristic curve analysis showed that the predicted CRP levels on POD1 was significantly associated with major complications after mastectomy (P = 0.0259) and laparoscopic colon surgery (P = 0.0049). The measured and predicted CRP levels significantly increased in the order of severity of postoperative complications (P < 0.01).

Conclusion

Increases in duration of surgery, intraoperative nociceptive level and preoperative CRP level were selected to predict early increases in CRP level after non-cardiac surgery under general anesthesia. Predicted CRP levels on POD1 were likely associated with severity of postoperative complications.

Association between intraoperative nociception and postoperative complications in patients undergoing laparoscopic gastrointestinal surgery

A higher degree of surgical invasiveness, which increases intraoperative nociception, might induce postoperative complications. Although several nociceptive indices for use during surgery are available in clinical practice, association between intraoperative nociception and postoperative complications has not been reported. An index representing intraoperative nociception, which is the averaged value of Nociceptive Response throughout the surgery (mean NR) was applied to examine the association in the present study. The retrospective study evaluated consecutive adult patients undergoing laparoscopic gastrointestinal surgery, American Society of Anesthesiologists-physical status (ASA-PS) I or II, whose preoperative C-reactive protein level was < 0.3 mg dL^-1. We first used ordinal logistic analysis to examine the association between preoperative and intraoperative risk factors and complications graded by the Clavien-Dindo classification. Next, we performed propensity score matched analysis to evaluate the effects of mean NR throughout surgery on postoperative complications. Ordinal logistic analysis (n = 158) revealed that duration of surgery (P < 0.001), mean NR during surgery (P = 0.002), and ASA-PS (P = 0.016) were risk factors for postoperative complications. Then all patients were divided into two propensity score matched groups, based on a mean NR of < 0.85 and ≥ 0.85, with matching for age, ASA-PS, body mass index and duration of surgery. The severity of postoperative complications was significantly higher in the high NR group than in the low NR group (P = 0.005). In conclusion, there was likely an association between intraoperative nociception and postoperative complications in patients without serious preoperative conditions and comorbidities.