Predictors of Acute Postsurgical Pain following Gastrointestinal Surgery: A Prospective Cohort Study

Preoperative frailty predicts postoperative pain after total knee arthroplasty in older patients: a prospective observational study

PURPOSE

Frailty is reportedly associated with postoperative adverse outcomes and may increase the risk of post-surgical pain. Our study aimed to explore whether frailty was an independent risk factor for pain after total knee arthroplasty (TKA) in older patients.

METHODS

Included in this prospective observational study were patients aged 65 or older who underwent primary TKA. Frailty of the patients was assessed before surgery using the comprehensive geriatric assessment-frailty index and pain was evaluated before and after surgery using the Numerical Rating Scale.

RESULTS

Of the 164 patients including 125 females with a mean age of 71.4 ± 4.6 years, 51 patients were identified as being frail. Patients with chronic post-surgical pain had a significantly higher frailty index than those without chronic post-surgical pain, which was the same in patients with acute post-surgical pain. After adjusting for other confounding factors, frailty was shown to be an independent risk factor for both acute (OR: 13.23, 95% CI 3.73-46.93, P < 0.001) and chronic post-surgical pain (OR: 4.24, 95% CI 1.29-14.00, P = 0.02). The area under the receiver operating characteristic curve for frailty predicting chronic post-surgical pain was 0.73 (P < 0.001, 95% CI 0.65-0.81).

CONCLUSIONS

Our findings demonstrated that preoperative frailty in older patients was a predictor of acute and chronic post-surgical pain after TKA, suggesting that frailty assessment should become a necessary procedure before operations, especially in older patients.

Blocking brown adipocyte β3-adrenoceptor attenuates blood-spinal cord barrier impairment and chronic postsurgical pain in a rat model of preoperative stress

Preoperative stress has been recognized as an independent risk factor for chronic postsurgical pain (CPSP). However, the underlying mechanisms of CPSP influenced by preoperative stress remain elusive. Previous studies indicated that excessive stress could induce disruption of the blood-spinal cord barrier (BSCB). We wondered whether and how BSCB involves in CPSP by using a single prolonged stress (SPS) combining plantar incision model in male rats to mimic preoperative stress-related postsurgical pain. Here, we observed that preoperative SPS-exposed rats exhibited relentless incisional pain, which was accompanied by impairment of BSCB and persistent elevation of serum IL-6. Intraperitoneal injections of Tocilizumab (an IL-6 receptor monoclonal antibody) not only mitigated BSCB breakdown but also alleviated pain behaviors. In addition, intervening β3-adrenoceptor (ADRB3) signaling in brown adipocytes by SR59230a (a specific ADRB3 antagonist) treatment or removal of brown adipose tissues could effectively decrease serum IL-6 levels, ameliorate BSCB disruption, and alleviate incisional pain. Further results displayed that SI-exposed rats also showed markedly spinal microglia activation. And exogenous His-tagged IL-6 could pass through the disrupted BSCB, which might contribute to microglia activation. Injection of SR59230a or ablation of brown adipose tissues could effectively reduce the activation of spinal microglia. Thus, our findings suggest that serum IL-6 induced by brown adipocyte ADRB3 signaling contributed to BSCB disruption and spinal microglia activation, which might be involved in preoperative stress mediated CPSP. This work indicates a promising treatment strategy for preoperative stress induced CPSP by blocking ADRB3.

Post-operative pain following percutaneous nephrolithotripsy- clinical correlates

OBJECTIVES

Management of postoperative pain following percutaneous nephrolithotripsy (PCNL) is a significant goal. We sought to identify risk factors and clinical correlates of postoperative pain in order to improve perioperative management and patient satisfaction.

MATERIALS AND METHODS

A single-center, retrospective analysis, from a prospectively maintained database, of all consecutive patients who underwent PCNL for renal calculi between January 2011 and August 2018. Postoperative pain was assessed using the visual analog scale (VAS) and analgesic use. We considered VAS score above 4 as meaningful. Pain management was standardized according to patirnt reported VAS scores. Multivariable logistic regression was performed to identify risk factors and clinical correlates.

RESULTS

A total of 496 patients were analyzed. Younger age was associated with VAS above 4 on the operative day and the first postoperative following PCNL (p = 0.003 and p < 0.001, respectively). Female gender was associated with VAS above 4 in the first 2 days following the operation (p < 0.001).

CONCLUSIONS

Younger age and female gender would most likely benefit from pre-emptive improved pain management protocols following PCNL.

Risk factors for chronic postsurgical pain in visceral surgery: a matched case–control analysis

Purpose

Chronic postsurgical pain (CPSP) after abdominal visceral surgery is an underestimated long-term complication with relevant impact on health-related quality of life and socioeconomic costs. Early identification of affected patients is important. We aim to identify the incidence and risk factors for CPSP in this patient population.

Methods

Retrospective case–control matched analysis including all patients diagnosed with CPSP after visceral surgery in our institution between 2016 and 2019. One-to-two case–control matching was based on operation category (HPB, upper-GI, colorectal, transplantation, bariatric, hernia and others) and date of surgery. Potential risk factors for CPSP were identified using conditional multivariate logistic regression.

Results

Among a cohort of 3730 patients, 176 (4.7%) were diagnosed with CPSP during the study period and matched to a sample of 352 control patients. Independent risk factors for CPSP were age under 55 years (OR 2.64, CI 1.51–4.61), preexisting chronic pain of any origin (OR 3.42, CI 1.75–6.67), previous abdominal surgery (OR 1.99, CI 1.11–3.57), acute postoperative pain (OR 1.29, CI 1.16–1.44), postoperative use of non-steroidal anti-inflammatory drugs (OR 3.73, OR 1.61–8.65), opioid use on discharge (OR 3.78, CI 2.10–6.80) and length of stay over 3 days (OR 2.60, CI 1.22–5.53). Preoperative Pregabalin intake was protective (OR 0.02, CI 0.002–0.21).

Conclusion

The incidence of CPSP is high and associated with specific risk factors, some of them modifiable. Special attention should be given to sufficient treatment of preexisting chronic pain and acute postoperative pain.

Cutoff Values for Providing the Ideal Intravenous Patient-Controlled Analgesia According to the Intensity of Postoperative Pain—A Retrospective Observational Study

Background and Objectives: The cutoff values were analyzed for providing the ideal intravenous patient-controlled analgesia (PCA) that could reduce rescue analgesics or antiemetics requirements, based on the grades of postoperative pain intensity (PPI). Materials and Methods: PCA regimens of 4106 patients were retrospectively analyzed, and they were allocated into three groups with low, moderate, and high PPI grades (groups L, M, and H, respectively) based on numeric rating scores obtained 6 h postoperatively. Opioid and non-opioid analgesic doses were converted into fentanyl-equivalent doses (DOSE-FEN-OP and DOSE-FEN-NONOP, respectively). The primary endpoint was the cutoff values of these parameters. Results: With respect to the PCA settings to reduce rescue analgesic and antiemetic requirements, group L required a background infusion rate (BIR) of 1.75–3 mL/h, bolus volume of 0.5–1.25 mL, and lockout interval of ≤12.5 min. Group M required a BIR of 1.75 mL/h, bolus volume of 0.5–1.75 mL, and lockout interval of ≤5 min. Group H required a BIR of 1.75 mL/h, bolus volume of 0.5 mL, and lockout interval of ≤5 min. In assessments of the analgesic doses to reduce rescue analgesic requirement, the DOSE-FEN-OP was at least 950 μg of fentanyl regardless of group, while the DOSE-FEN-NONOP was ≥250 μg, ≥550 μg, and ≥700 μg for the L, M, and H groups, respectively. In assessments of the analgesic doses to reduce rescue antiemetic requirement, DOSE-FEN-OP was ≤950 μg for groups L and M and ≤850 μg for Group H, while DOSE-FEN-NONOP was ≤50 μg, ≤450 μg, and ≤700 μg for groups L, M, and H, respectively. Conclusion: The ideal PCA for reduction in rescue analgesics or antiemetics can be achieved by adjustment of PCA settings and drug dosages carefully with these cutoff values depending on the expected grades of PPI. Especially, the ideal PCA can be provided by adjusting the lockout interval and bolus volume rather than BIR and by applying smaller bolus doses and shorter lockout intervals with an increasing PPI grade.