The Usefulness of Preoperative Airway Characteristics as Predictors of Dental Trauma during Laryngoscopy / 대한마취과학회지

BACKGROUND: Damage to teeth has long been associated with endotracheal intubation. But, no rules designed to predict dental injuries have been formulated. In this prospective study, we undertook to identify relationships between anatomic airway measurements used customarily in bedside practice, and blade-tooth distance during laryngoscopy, to assess the usefulness of these anatomic measurements as predictors of dental injury. METHODS: Four hundred and eighty-three patients scheduled for elective surgery requiring general anesthesia with endotracheal tube placement were included. During a preoperative visit, a number of measurements and assessments of features that might predict difficult intubation were performed. When optimum visibility of the glottis was obtained during laryngoscopy, the distance between the flange of the blade and the upper incisor was measured. We determined which of the individual airway characteristics correlated with the blade-tooth distance and best predicted the potential of dental injury. RESULTS: The blade-tooth distance was found to correlate with the individual scales of the Mallampati classification (Spearman's correlation coefficient, r = - 0.356, P < 0.01), mandibular protrusion (r = - 0.390, P < 0.01), head and neck movement (r = - 0.276, P < 0.01), interincisor gap (r = - 0.648, P < 0.01), and the condition of the upper teeth (r = - 0.313, P < 0.01). The frequency of direct blade-tooth contact significantly increased as the scales of these five anatomic measurements increased (P < 0.01). CONCLUSIONS: This study shows for the first time that some airway measurements are correlated with blade-tooth distance, and that they can be considered as useful predictors of dental injury during laryngoscopy.

Acute Renal Artery Thromboembolism during Abdominal Aortic Bypass Graft Surgery / 대한마취과학회지

Acute occlusion of the artery to a single functioning kidney is a rare but surgically correctable cause of acute renal failure. A young-aged woman with acute renal failure and anuria due to a thromboembolism of the right renal artery was surgically treated 2 hours after the onset of anuria. Revascularization resulted in the reversal of renal failure and complete recovery of renal function. An aggressive diagnostic and therapeutic approach is important whenever occlusion of the renal artery is suspected during surgery in Takayasu arteritis patients.

Effect of PaCO2, PETCO2, P(a-ET)CO2 and Regional Cortical Blood Flow on the Prognosis of Craniotomy Patients / 대한마취과학회지

BACKGROUND: Carbon dioxide is a potent cerebral vasodilator. The change of carbon dioxide partial pressure may influence the intracranial pressure and the patients' neurological outcome. There are few reports about the influence of end-tidal CO2 (ETCO2), arterial CO2 (PaCO2) and its pressure difference P(a-ET)CO2 during a craniotomy on the Glasgow coma scale (GCS) score for evaluation of neurological status. In this study, authors tried to discover the influence of PaCO2, PETCO2, and P(a-ET)CO2 on neurological outcome. METHODS: The data of PaCO2 and PETCO2 and P(a-ET)CO2 during a craniotomy was saved. The correlations between each parameter, the GCS score and rCoBF were analyzed. To prevent a direct effect on carbon dioxide tension, blood pressure and body temperature were maintained within a normal range. At the same time, we inserted a probe of the thermal diffusion flowmetry monitor in the subdural space to monitor the regional cortical cerebral blood flow (rCoBF). All the data was saved simultaneously, at the moment of dura closure. RESULTS: There was a fair correlation between the PaCO2 and PETCO2. A low PaCO2 level correlated well with a good GCS score but, not with PETCO2. The mean P(a-ET)CO2 value was 4.4 +/- 3.1 mmHg. The high P(a-ET)CO2 level correlated well with a poor GCS score. High rCoBF correlated well with a good GCS score. However, the changes of PaCO2 and PETCO2 showed no correlations with the rCoBF. CONCLUSIONS: As a result, if we decrease the PaCO2 level by hyperventilation and increase the rCoBF level through proper management during anesthesia, we can improve the patients' neurological outcome.