Effect of palmitoylethanolamide on inflammatory and neuropathic pain in rats / 대한마취과학회지

BACKGROUND: A growing body of evidence suggests that neuroinflammation, which is characterized by infiltration of immune cells, activation of mast cells and glial cells, and production of inflammatory mediators in the peripheral and central nervous systems, plays an important role in the induction and maintenance of chronic pain. Palmitoylethanolamide (PEA), which is a type of N-acylethanolamide and a lipid, has an anti-inflammatory effect. Relative to the anti-inflammatory effect, little is known about its analgesic effect in chronic pain. This study aimed to determine whether PEA relieves chronic inflammatory and neuropathic pain. METHODS: Male Sprague-Dawley rats were injured by transection of the left L5 and L6 spinal nerves to induce neuropathic pain or were injected with monoiodoacetic acid into the synovial cavity of knee joints to induce inflammatory pain. To assess the degree of pain, two kinds of stimuli - pressing von Frey filaments and wetting with acetone - were applied to the plantar surface of the rat to measure mechanical and cold sensitivity, respectively. Pain was measured by assessing behavioral responses, including paw withdrawal response threshold and paw withdrawal frequency upon stimulation. RESULTS: Neuropathic pain caused by spinal nerve transection (SNT) decreased the mechanical threshold and increased the frequency of response to acetone application. But, cold allodynia caused by SNT did not decrease the withdrawal frequency. Mechanical hyperalgesia caused by chronic inflammation was significantly reduced by both intraperitoneal and intra-articular injections of PEA. CONCLUSIONS: These outcomes revealed that PEA might be effective in relieving inflammatory and neuropathic pain, especially pain induced by mechanical hyperalgesia, but not cold allodynia.

Awareness during General Anesthesia due to Vaporizer Malfunction: A case report / 대한마취과학회지

We report a case of awakening during general anesthesia due to a vaporizer malfunction. The sevoflurane vaporizer had a hole through which approximately 20% of fresh gas escaped. The gas in the common gas outlet contained only 60% of the sevoflurane stated on the vaporizer setting. Moreover, the gas monitor module was out of order, and the heart rate and blood pressure were stable. As a result, we were unaware of the low sevoflurane concentration. The leakage through the hole could not be detected with the commonly used low-pressure system leak checking method. The implication of this case is that unexpected awakening can occur in patients with stable vital signs with an inhalation anesthesia. Therefore, more attention is needed to detect the level of patient awareness.

Perioperative Hypotension due to Systolic Anterior Motion of the Mitral Valve with Left Ventricular Outflow Track Obstruction during Off-Pump Coronary Artery Bypass Surgery: A case report / 대한마취과학회지

Systolic anterior motion of the mitral valve (SAM) is well known in the concentric left ventricular hypertrophy or post mitral valvuloplasty. However, SAM has not been reported in Off-pump coronary artery bypass surgery (OPCAB). Preoperatively, SAM in combination with a left ventricular outflow tract obstruction leads to severe cardiovascular destabilization. Moreover, a diagnosis of SAM is very important because the administration of conventional therapy to hypotension can aggravate SAM. We report a patient with un-identified left ventricular wall hypertrophy or mitral valve regurgitation, who was diagnosed with SAM by TEE during OPCAB. This report describes the diagnostic and therapeutic strategies for the perioperative management of SAM.