Zinc deficiency: A cause of opioid-induced physical dependence and addiction in post-operative total hip arthroplasty patients.

OBJECTIVES: Recently, opioid abuse and related overdoses have increased warranting the need for research directed against the opioid epidemic. Previous studies identified that patients on opioid therapy may become zinc deficient and that zinc, in a murine model, may antagonistically affect the opioid receptor.13 Further understanding the relationship between opioid use and zinc deficiency may mitigate the opioid epidemic. METHODS: A retrospective study was conducted to identify zinc (Zn2+) deficiencies among post-operative total hip arthroplasty (THA) patients. On post-operative day one, patients had routine blood tests, including Zn2+ plasma levels. Patients were considered Zn2+-deficient if their Zn2+ plasma was < 56 µg/dL (Reference: 56-134 µg/dL). Upon discharge from the hospital, the patients' inpatient opioid medication consumption per day was determined by dividing total morphine milligram equivalents (MMEs) by length of stay. A Student's t-test was performed to compare the total MMEs for Zn2+-deficient patients versus Zn2+-normal patients. A univariate analysis followed by multiple linear regression was performed to identify demographic or surgical predictors of MMEs/day. RESULTS: For Zn2+-deficient patients, the total MMEs/day was 33.62 ( ± 27.06), as compared to Zn2+-normal patients who consumed 16.22 ( ±16.01) MMEs/day (p = 0.031). The univariate analysis and multiple linear regression showed that patients' Zn2+ status had a significant contribution toward predicting MMEs/day, with p = 0.022 and p = 0.04, re-spectively. CONCLUSION: The results of this study suggest that Zn2+ deficiency may potentiate opioid consumption. Thus, Zn2+ sup-plementation may be a simple approach to reducing opioid addiction and dependence.

Adductor Canal Block or Local Infiltrate Analgesia for Pain Control After Total Knee Arthroplasty? A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Total knee arthroplasty is a treatment option for debilitating arthritis. In the postoperative period, patients experience moderate to severe pain affecting the rehabilitation, hospital stay, and patient satisfaction. This study aims at utilizing current best evidence to determine whether adductor canal block (ACB) or periarticular injection (PAI) is a better modality for managing short-term postoperative pain and opioid consumption. METHODS: Embase, MEDLINE, HealthStar, Emcare, and PubMed were searched for randomized controlled trials from 1946 to August 2018, for literature addressing the comparison of ACB and PAI for pain management in the setting of total knee arthroplasty. A systematic review and meta-analysis were performed. RESULTS: Six studies were included in our meta-analysis. When examining the combined visual analog scale (VAS) pain values for each group, analysis demonstrated greater reduction in scores for the PAI group, and the difference was statistically significant (P = .001). When comparing the VAS scores of subgroups analyzed at specific periods in time, there was a trend toward lower VAS scores in subgroups analyzed at 24 hours and 48 hours postoperatively (at rest and at movement) in the PAI group. Overall opioid consumption was lower in the PAI group, with demonstrated statistical significance (P = .03). When comparing the postoperative subgroups, there was a trend toward decreased opioid use in the PAI group, with 13.25% less opioid use at 48 hours and 9.5% less opioid use at 24 hours. CONCLUSION: PAI could significantly improve postoperative pain and opioid consumption when compared with ACB. Additional, high-quality studies are required to further address this topic.

Periarticular regional analgesia in total knee arthroplasty: a review of the neuroanatomy and injection technique.

Postoperative pain control after total knee arthroplasty may be insufficient, resulting in insomnia, antalgic ambulation, and difficulty with rehabilitation. Current strategies, including the use of femoral nerve catheters, may control pain but have been associated with falls, motor blockade, and quadriceps inhibition. Periarticular infiltration using the appropriate technique and knowledge of intraarticular knee anatomy may increase pain control and maximize rehabilitation.

Blood loss management in high-risk patients undergoing total knee arthroplasty: a comparison of two techniques.

Although it is well known that patients with preoperative hemoglobin levels <13.0 g/dL are at a higher risk for requiring postoperative transfusions, the ideal blood management strategy for this group of patients remains unclear. This study compared preoperative autologous donation with preoperative administration of epoetin alfa as a method to maximize perioperative hemoglobin levels and minimize blood transfusions in these high-risk patients undergoing total knee arthroplasty (TKA). Results show that both preoperative autologous donation and epoetin alfa were successful in decreasing the need for allogeneic blood transfusions following TKA in high-risk patients. Epoetin alfa was more effective in maximizing perioperative hemoglobin levels.

Orthopaedic-induced anemia: the fallacy of autologous donation programs.

Total knee arthroplasty is associated with significant blood loss. Despite the initiation of various blood conservation modalities, allogeneic transfusion has yet to be eliminated. One hundred forty-eight patients who had unilateral primary total knee arthroplasties during a 3-year period were evaluated retrospectively for blood loss and transfusion rates. The patients were prescribed one unit of preoperative autologous donation that was to be transfused automatically on postoperative Day 1. Allogeneic transfusion was based on symptoms, and no numerical transfusion triggers were used. The preoperative autologous donation program resulted in increased preoperative anemia. Whereas only 26.2% of patients were in the high transfusion-risk group (hemoglobin >10 g/dL and < or = 13 g/dL) before surgery, 55.7% of patients were in this high-risk category after preoperative autologous donation. The patients did not recover from the autologous donations that occurred 4 weeks before surgery. A mean hemoglobin level of 14.0 g/dL was seen before donation, whereas the mean preoperative hemoglobin level decreased to 12.6 g/dL. We think that a preoperative autologous donation program leads to an increased risk of anemia before surgery.