Does alkalinization of 0.75% ropivacaine promote a lumbar peridural block of higher quality?

Thoracoscopic Intercostal Nerve Block with Cocktail Analgesics for Pain Control After Video-Assisted Thoracoscopic Surgery: A Prospective Cohort Study

Objective

To evaluate whether using a cocktail of intercostal nerve blocks (TINB) during thoracoscopic surgery results in better clinical outcomes than patient-controlled analgesia (PCIA).

Methods

Patients in two medical groups undergoing video-assisted thoracoscopic surgery (VATS) for pulmonary nodules in West China Hospital of Sichuan University were collected consecutively between March 2022 and December 2022. The groups were divided into two subgroups based on their analgesic program, which were TINB group and PCIA group. The primary outcome was the visual analogue scale (VAS) of the two groups at different stage after surgery and after discharge. Any analgesic related adverse events (ARAEs) were also recorded.

Results

A total of 230 patients who underwent VATS were enrolled, in which 113 patients (49.1%) received a cocktail TINB after surgery, and 117 patients (50.9%) received a PCIA. After PSM, 62 patients in each group were selected. The difference of resting VAS (RVAS) and active VAS (AVAS) at different stage during hospitalization was only related to the change of period (p < 0.05, p < 0.05), and the two groups showed no significant differences in RVAS or AVAS during hospitalization (p = 0.271, p = 0.915). However, the rates of dizziness (4.84% vs 25.81%, p = 0.002), nausea and vomiting (0 vs 22.58%, p < 0.05), fatigue (14.52% vs 34.87%, p = 0.012), and insomnia (0 vs 58.06%, p < 0.05) in TINB group were lower than that in PCIA group. Besides, AVAS and RVAS at 7, 14, and 30 days after discharge in TINB group were both significantly lower than that in PCIA group (p < 0.05, p < 0.05).

Conclusion

Cocktail TINB provided better analgesia after discharge and reduced the incidence of ARAEs in patients undergoing VATS.

Efficacy of a Modified Cocktail for Periarticular Local Infiltration Analgesia in Total Knee Arthroplasty: A Prospective, Double-Blinded, Randomized Controlled Trial

BACKGROUND

Periarticular local infiltration analgesia (LIA) is largely utilized for controlling pain after total knee arthroplasty (TKA). The present work aimed to assess the efficacy of a modified LIA cocktail for patients undergoing TKA.

METHODS

Magnesium sulfate (MgSO4) and sodium bicarbonate (NaHCO3) were added to a conventional LIA cocktail comprising ropivacaine, epinephrine, and dexamethasone. After the safety of this modified cocktail was tested in rats, its efficacy and safety were evaluated in a prospective, double-blinded study including 100 individuals randomized to receive periarticular infiltration of the modified cocktail or a conventional cocktail. The primary outcome was postsurgical use of morphine hydrochloride for rescue analgesia. Secondary outcomes were the time until the first rescue analgesia, postsurgical pain (on a visual analog scale [VAS]), functional recovery (assessed by range of knee motion and ambulation distance), time to discharge, and complication rates.

RESULTS

Adding NaHCO3 to the local anesthetics caused some instantaneous precipitation in all cases. Administering the modified cocktail to rats did not obviously damage the injected area of the nerve or surrounding tissues. Administration of the modified cocktail to patients was associated with markedly reduced postsurgical morphine use in the initial 24 hours (4.2 ± 5.0 versus 14.6 ± 8.9 mg, p < 0.001), reduced total morphine use (9.8 ± 8.4 versus 19.6 ± 11.4 mg, p < 0.001), prolonged time to the first rescue analgesia, lower VAS pain scores at rest and during motion at 12 and 24 hours following the operation, better functional recovery on postoperative days 1 and 2, and a shorter hospital stay. The modified and conventional cocktail groups had similar rates of complications.

CONCLUSIONS

The present modification of a conventional cocktail significantly prolonged analgesia and reduced opioid consumption, which may substantially improve pain control in arthroplasty.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Comparison of the antibacterial activity of lidocaine 1% versus alkalinized lidocaine in vitro

BACKGROUND

Infections after epidural and spinal blocks are rare. The topical anesthetic liclocaine used in these procedures has been found to have antibacterial effects on various microorganisms.

OBJECTIVE

The aim of this study was to assess the antibacterial effects of alkalinized liclocaine on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.

METHODS

Lidocaine 2%, alkalinized lidocaine, and physiologic saline (as a control solution) were added to standard bacterial preparations. The final concentration of the lidocaine was 10 mg/mL (1%). At baseline and 3 and 6 hours after incubation at 37°C, 3-mL aliquots were vortexed and pipetted into sterile polystyrene spectrophotometer cuvettes. Baseline referred to the end of the period of preparation of the solution (≤20 minutes). Growth was measured as the optical density at a wavelength of 540 nm.

RESULTS

Compared with the control, lidocaine significantly inhibited the growth of S aureus, E coli, and P aeruginosa at baseline and 3 and 6 hours after incubation (all, P < 0.05). Alkalinized lidocaine significantly inhibited the growth of S aureus at baseline and 3 and 6 hours (all, P < 0.05), while it significantly inhibited the growth of E coli and P aeruginosa only at 6 hours (both, P < 0.05). The growth of E coli was significantly less in lidocaine than in alkalinized lidocaine at 0 and 3 hours (both, P < 0.05).

CONCLUSION

The antibacterial effect of lidocaine 1% on S aureus was not changed after alkalinization. The effect of alkalinized lidocaine on E coli and P aeruginosa was significant only at 6 hours. Lidocaine significantly inhibited the growth of these 3 microorganisms at all study periods.