Distribution of Elastic and Collagen Fiber in Uvular Tissue of Patients with Obstructive Sleep Apnea and Snorers / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Sleep related obstructive breathing disorders are frequently observed in adults. Despite extensive work of recent years, the essential pathophysiologic mechanism that mediates this process is still unclear. This study was conducted to determine whether distribution of connective tissue in the uvula is different among apneics, snorers and normal controls. MATERIALS & METHODS: Uvula was obtained by uvulopalatopharyngoplasty in 8 apneics, 6 snorers (mean apnea index: 17.1, 2.43 respectively) and by autopsy in 5 individuals not known to have snoring. The surgical specimen of uvula was fixed in 10% formalin and subsequently embedded in paraffin. Each specimen was cut into 5 micrometer-thick section and stained with hematoxylin-eosin for general appearance, Masson-Trichrome stain for collagen fiber, and Verhoeff stain for elastic fiber. Microscopic examination was performed by two pathologists who were blinded to the polysomnographic data. RESULTS: Infiltration of inflammatory cells and edema were significantly increased in the snorer and apneic groups compared with the control group (p<0.0001, p<0.05 respectively). Compared with the normal group, the density of elastic fibers and collagen fibers were significantly decreased in snorers and apneics (elastic fiber: p<0.0005, collagen fiber: <0.01). The distribution of elastic and collagen fiber showed significantly heterogeneous patterns in the snorer and apneic group compared to the control group (elastic fiber: p<0.001, collagen fiber: p<0.0005). CONCLUSION: Since connective tissue fibers have the supportive function in the body, this condition may result in increased collapsibility of upper airway and contributes to the development of obstructive sleep apnea.

Effects of Peritonsillar Infiltration with Bupivacaine and Oral Dextromethorphan on Post-Tonsillectomy Pain / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Peripheral tissue or nerve injury often leads to post-injury pain hypersensitivity caused by peripheral and central sensitization. Central sensitization which plays a significant role is triggered by nociceptive afferent inputs and mainly results from N-methyl-D-aspartic acid (NMDA) receptor activation. If the afferent impulses are prevented from gaining access to the CNS or if NMDA receptor is blocked by antagonist, central sensitization will not develop and then less pain will result. Previous studies demonstrated that preoperative infiltration of local anesthetics or oral NMDA receptor antagonist could alleviate postoperative pain. We investigated the effects of peritonsillar infiltration with bupivacaine and oral dextromethorphan on post-tonsillectomy pain. MATERIALS AND METHODS: Forty consecutive patients were randomly allocated to one of four groups. Group I was bupivacaine-treated group, and group II was dextromethorphan-treated group. Group III was both bupivacaine and dextromethorphan-treated group, and group IV was control group. Pain scores were assessed using self-rating numeric rating scale ( NRS) at rest and on swallowing during the postoperative day 0, 1, 2, and 7. Doses of supplementary diclofenac administered postoperatively were also recorded. RESULTS: Group I, II, and III showed significantly lower NRS pain scores compared with control group at rest and on swallowing throughout the postoperative 7 days. Diclofenac doses were not statistically different among the four groups. CONCLUSION: Preoperative peritonsillar infiltration with bupivacaine and/or medication with dextromethorphan contributed to decrease the intensity of postoperative pain after tonsillectomy.