The Inhibitory Effects of Local Anesthetics on Primary Sensory Nerve and Parasympathetic Nerve in Rabbit Eye

Phrenic nerve infiltration: A good practice to combine pulmonary expansion and pain control in patients with high risk of prolonged air leak

OBJECTIVE

Prolonged air leak due to residual air space after lung resection is a main challenge. To date, few surgical options have been described to prevent this complication. The aim of this study is to investigate the safety and the efficacy of intraoperative phrenic nerve infiltration with long-acting anesthetics in producing transient hemidiaphragm paralysis in patients at high risk for prolonged air leak, thus improving pulmonary expansion after surgery and reducing air leaks, while controlling postoperative pain.

METHODS

Between January 2021 and 2023, 65 consecutive patients at risk for prolonged air leak (defined in accordance with "2019 Society of Thoracic Surgery score criteria of prolonged air leak") who underwent lung resection (lobectomy or anatomic segmentectomy) for malignancy were prospectively included in the study. They were randomly (1:2 ratio) assigned to receive (group A, 22 patients) intraoperative phrenic nerve infiltration with ropivacaine 10 mg/mL in the peri-neurotic fat on the pericardium or not to receive intraoperative phrenic nerve infiltration (group B, 43 patients). Five patients in group B were excluded because they did not undergo anatomic resection. Data on pulmonary reexpansion, prolonged air leaks, pain at 24 and 72 hours postsurgery, referred shoulder pain, length of hospital stay, and length of chest tube permanence were collected and compared.

RESULTS

Hemidiaphragm elevation (P = .006) and pulmonary expansion (P = .000) were significantly higher in group A. Patients in group A showed lower pain at 24 and 72 hours compared with group B (P = .004). Shoulder pain (0.001) and prolonged air leak (0.000) were higher in group B. Length of chest tube was longer in group B. No difference in hospital stay length was observed.

CONCLUSIONS

This is the first study to investigate 2 combined effects of phrenic nerve anesthetic infiltration (hemidiaphragm elevation and pain control), with potential enhancement of a patient's recovery after surgery. Intraoperative phrenic nerve infiltration in patients with a risk for prolonged air leak appears to be a safe and effective clinical practice to improve pulmonary expansion in this set of patients, reducing postoperative air leak. This result is associated with an additional improvement in pain control, especially for shoulder pain.

Dermal effects and pharmacokinetic evaluation of the lidocaine/prilocaine cream in healthy Chinese volunteers

BACKGROUND

EMLA cream is a local anesthetic. The pharmacokinetics and dermal effects of a topical anesthetic formulation has not been evaluated in healthy Chinese volunteers.

MATERIALS AND METHODS

The Pharmacokinetics of the lidocaine/prilocaine test (T) or reference (R, EMLA) cream were evaluated in a fasting, single-dose, two-period crossover bioequivalent study conducted in 40 healthy Chinese volunteers. Meanwhile, the dermal effects including blanching, erythema, temperature sensation, edema, and skin rash were also evaluated during the study.

RESULTS

After applied 15 g of the cream for 4 h to a 100 cm2 area under plastic occlusive film on the skin of the thigh of healthy volunteers, the results of the pharmacokinetic study showed that the active components absorbed in skin from topical products was relatively low compared with most system absorption drugs. After the removal of the residual anesthetic cream, there was a vascular biphasic response with initial transient blanching which reaches a peak at 4.5 h and later more persisting period erythema. The change of temperature sensory sensitivity reached the peak value at 4.5-6 h.There was no statistically significant difference of the changes after application the lidocaine/prilocaine T or R cream in subjects. In general, the lidocaine/prilocaine T or R cream was well tolerated.

CONCLUSION

The method described a model for investigations of pharmacokinetics and pharmacodynamics of topical lidocaine/prilocaine cream. Except the plasma drug level indicator, these pharmacodynamics data should also be evaluated in the anesthetic transdermal pharmacokinetics study.

CLINICAL TRIAL REGISTRATION

CTR20211544; registered in http://www.chinadrugtrials.org.cn/ at September 2021.

Effects of ultrasound-guided erector spinae plane block on postoperative analgesia and plasma cytokine levels after uniportal VATS: a prospective randomized controlled trial

PURPOSE

Although uniportal video-assisted thoracoscopic surgery (VATS) has been widely used, the associated postoperative pain is still severe. Currently, a variety of regional anesthesia methods have been used to relieve postoperative pain. In our study, we wanted to evaluate the effectiveness of ultrasound-guided erector spinae plane block (ESPB) as a postoperative analgesia after uniportal VATS.

METHODS

Eighty patients scheduled to undergo uniportal VATS were randomly divided into Group ESP and Group C. In Group ESP, the patients underwent ultrasound-guided ESPB under general anesthesia before surgery, while Group C was set as blank control group without ESPB. The primary outcome was the sufentanil dose within 24 h after surgery. The secondary outcomes mainly included postoperative pain scores at 2, 4, 8, and 24 h evaluated using a numeric rating scale (NRS), intraoperative opioid dosage, levels of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) in the plasma, side effect profile, and length of postoperative hospital stay.

RESULTS

Postoperative sufentanil consumption (32.5 ± 6.3 μg vs. 42.8 ± 7.6 μg, P < 0.001) was significantly lower in Group ESP than in Group C. Intraoperative sufentanil consumption was significantly lower in Group ESP than in Group C (P < 0.001). The postoperative NRS score and levels of inflammatory cytokines were significantly lower in Group ESP than in Group C (P < 0.05).

CONCLUSIONS

Ultrasound-guided ESPB decreased the consumption of sufentanil both postoperatively and intraoperatively for patients undergoing uniportal VATS and appeared to be an effective treatment option.

Morphofunctional interactions of peripheral nerve fibers of the iris with neurons developing in the anterior chamber of the eye in rats

Electron microscopic studies were performed on intraocular transplants of embryonic septal and hippocampal tissue developing in the anterior chamber of the eye in rats for 3-4 months. The aim of the study was to seek ultrastructural identification of peripheral nerve fibers entering transplants from the iris, and to assess their ability to establish true synaptic contacts with transplanted CNS neurons. Bundles of myelinated and unmyelinated axons surrounded by Schwann cell cytoplasm were seen within the perivascular spaces of ingrowing blood vessels. Both types of peripheral fiber were also identified in the neuropil areas of transplants. At the ultrastructural level, unmyelinated axons were found to be free of glial Schwann cell sheaths and to form typical asymmetrical synapses with the dendrites and dendritic spines of transplant neurons. These results provide evidence of the high morphofunctional plasticity of both parts (central, peripheral) of the nervous system.