Multiple comparisons tests (MCTs) are performed several times on the mean of experimental conditions. When the null hypothesis is rejected in a validation, MCTs are performed when certain experimental conditions have a statistically significant mean difference or there is a specific aspect between the group means. A problem occurs if the error rate increases while multiple hypothesis tests are performed simultaneously. Consequently, in an MCT, it is necessary to control the error rate to an appropriate level. In this paper, we discuss how to test multiple hypotheses simultaneously while limiting type I error rate, which is caused by α inflation. To choose the appropriate test, we must maintain the balance between statistical power and type I error rate. If the test is too conservative, a type I error is not likely to occur. However, concurrently, the test may have insufficient power resulted in increased probability of type II error occurrence. Most researchers may hope to find the best way of adjusting the type I error rate to discriminate the real differences between observed data without wasting too much statistical power. It is expected that this paper will help researchers understand the differences between MCTs and apply them appropriately.
Analysis of Variance ; Hope ; Inflation, Economic

Analysis of variance (ANOVA) is one of the most frequently used statistical methods in medical research. The need for ANOVA arises from the error of alpha level inflation, which increases Type 1 error probability (false positive) and is caused by multiple comparisons. ANOVA uses the statistic F, which is the ratio of between and within group variances. The main interest of analysis is focused on the differences of group means; however, ANOVA focuses on the difference of variances. The illustrated figures would serve as a suitable guide to understand how ANOVA determines the mean difference problems by using between and within group variance differences.
Analysis of Variance* ; False Positive Reactions ; Inflation, Economic

BACKGROUND: Venous lidocaine retention with tourniquet has a possibility to prevent propofol injection pain efficiently. We performed the study to assess the efficacy of various intravenous lidocaine pretreatment methods with tourniquet on reducing propofol-induced injection pain, especially the effect of varying the concentration and dose of lidocaine. METHODS: In order to know the effect of lidocaine pretreatment with tourniquet on prevention of propofol-induced injection pain, one hundred patients were divided into four groups by the method of pretreatment; 1% lidocaine of 1 mg/kg (lidocaine pretreatment, LPT1 n = 25); 0.5% lidocaine of 1 mg/kg (LPT2, n = 25); 1% lidocaine of 0.5 mg/kg (LPT3, n = 25); 5 ml of saline pretreatment (saline pretreatment, SPT, n = 25). After 5 minutes of pretreatment, propofol-induced pain was measured immediately after injection of 1 mg/kg propofol with tourniquet inflation and after deflation of tourniquet, and after a second injection of 1 mg/kg propofol by use of the numerical rating scale and pain score of four categories. We selected maximal values of three times measurement for comparison. RESULTS: All groups of lidocaine pretreatment (pain incidence of LPT1; 20%, LPT2; 16% and LPT3; 36%, respectively) significantly reduced the incidence of propofol-induced injection pain compared to the saline pretreatment group (96%) (P <0.05). Lidocaine pretreatment groups had dramatically lower intensity of pain compared with saline pretreatment (P <0.05). However, there were no differences among the lidocaine pretreatment groups (P > 0.05). CONCLUSIONS: This result indicates that lidocaine pretreatment with tourniquet has an effect on the prevention of propofol-induced injection pain. However, we recommend pretreatment with 0.5 1% lidocaine of 1 mg/kg by use of tourniquet and propofol injection immediately after deflation of the tourniquet in practice.
Humans ; Incidence ; Inflation, Economic* ; Lidocaine* ; Propofol* ; Tourniquets*

PURPOSE: Inflation of an endotracheal tube cuff with adequate pressure is an important procedure. Passive release technique (PRT) is a useful and convenient method for inflating the cuff. To date, no study comparing this method with minimal occlusive volume technique (MOVT), one of the most commonly used methods for inflating the cuff, has been reported. We conducted this study for comparison of effectiveness, difficulty, and preference between the two methods. METHODS: We conducted a prospective, crossover, randomized study in which participants used each technique, one at a time. Participants inflated the cuff of an endotracheal tube inserted into a manikin after receiving brief education on use of the two methods. After inflating the cuff using each method, pressure and volume of the inflated cuff were measured using a portable manometer and syringes, respectively. Then, difficulty of each method was investigated using the visual analogue scale (VAS) and preference for each method was investigated. RESULTS: A total of 47 participants were enrolled in the study. The mean pressure between the two methods was not statistically different (p=0.27). However, adequate pressure was achieved in 37 (78.7%) and 16 (34.0%) of participants in PRT and MOVT, respectively (p<0.01). The mean volume was 6.0+/-0.4 ml in PRT and 5.7+/-0.6 ml in MOVT (p<0.01). The VAS score for diffculty was 17.7+/-15.8 in PRT and 76.0+/-15.8 in MOVT (p<0.01). Preference for PRT was 46(97.9%) and that for MOVT was 1 (2.1%). CONCLUSION: PRT is an easier, more preferred, and more effective method for cuff inflation than MOVT.
Inflation, Economic ; Intubation ; Manikins ; Prospective Studies ; Syringes

BACKGROUND: Core temperature changes during tourniquet inflation and deflation have been reported. The aim of this study is to investigate the extent of core temperature changes during inflation and deflation, depending on tourniquet time. METHODS: Esophageal temperature in sixty patients who undergoing knee arthroscopy with tourniquet longer than 1 h (group L, n = 30) and less than 1 h (group S, n = 30) were measured before inflation, 30 and 60 min after inflation, just before deflation, and 1 min interval for 10 min after deflation. RESULTS: Tourniquet time in L and S group was 109 +/- 20 min and 46 +/- 10.7 min, respectively. Compared to baseline value of 35.7 +/- 0.07 degrees C, significant increase of 0.14 +/- 0.02 degrees C, 0.25 +/- 0.03 degrees C, 0.4 +/- 0.05 degrees C were observed at 30, 60 min after inflation, and just before deflation, respectively in group L, and the increase of 0.11 +/- 0.03 degrees C and 0.18 +/- 0.03 degrees C at 30 min after inflation and just before deflation, respectively in group S. Temperatures from 2 to 10 min after deflation were significantly lower than value of just before deflation in each group (P < 0.05). At 10 min after deflation, 0.76 +/- 0.13 degrees C in group L and 0.4 +/- 0.04 degrees C in group S were lower than values of just before deflation in each group (P < 0.05). Temperature at 10 min after deflation was significantly different between the groups (P < 0.05). CONCLUSIONS: Extent of core temperature decrease after tourniquet deflation was dependent on the duration of tourniquet application.
Arthroscopy ; Humans ; Inflation, Economic ; Knee ; Tourniquets*

Pressure damage to respiratory mucosa from overinflation of bronchial cuffs has been implicated as a cause of bronchial rupture, a rare but devastating complication of double-lumen endobronchial tubes (DLTs). In vivo, we evaluated the pressure/volume characteristics of the bronchial cuffs by left main bronchus diameter and DLT size. Thirty patients were divided into three groups : in group 1, 35 Fr DLT was used and left main broncus diameter (LMBD) was less than 12 mm; in group 2, 37 Fr DLT and LMBD less than 12 mm ; in group 3, 37 Fr DLT and LMBD larger than 12 mm. The bronchial cuff volume needed to seal left main bronchus(cuff sealing volume) and bronchial cuff pressure to 2.5 ml of cuff volume at 0.5 ml increments were measured . The results were as follows. 1) The mean+SE cuff sealing volume were 0.3+/-0.1 ml, 0.4+/-0.1 ml and 1.0+/-0.2 ml in group 1, 2 and 3 respectively. 2) The mean+ SE bronchial cuff pressure at 0.5, 1, 1.5 and 2 ml of cuff volume were 27.5+/-5.0, 64.0+/-10.2, 105.4+/-15.5, 124.1+/-16.7 mmHg in group 1, 31.5+/-3.7, 74.1+/-6.2, 126.0+/-11.8, 175.3+/-14.6 mmHg in group 2 and 10.9+/-2.4, 23.8+/-3.4, 50.5+/-5.4, 89.2+/-7.5 mmHg in group 3 respectively. We concluded that initial cuff inflation volume of 0.5 ml in group 1 and 2, 1ml in group 3 is appropriate.
Bronchi* ; Humans ; Inflation, Economic ; Respiratory Mucosa ; Rupture

The author attempted to clarify the nature of alpha-adrenoceptors in relation to the pressor response to the increased intracranial pressure(ICP) in urethane-anesthetized rabbits, using the epidural balloon method. 1) The blood pressure increased in parallel with the raised ICP which was made by gradual inflation of the balloon. 2) B-HT 920, an alpha2-agonist, which elicited depressor and bradycardiac responses in normal rabbits inhibited markedly the pressor response to the raised ICP. 3) Piperoxan, an alpha2-antagonist, potentiated the pressor response to the raised ICP. 4) Piperoxan antagonized the depressor and bradycardiac responses by B-HT 920 as well as the inhibitory effect of B-HT 920 on the pressor response to the raised ICP. 5) The pressor response to the raised ICP were not affected at all by prazosin, an alpha1-antagonist. 6) Neither the depressor and bradycardiac responses by B-HT 920 itself nor the inhibitory effect of B-HT 920 on the pressor response to the raised ICP were significantly affected by prazosin. It is inferred from these observations that the central alpha-adrenoceptors play an important role in producing the pressor response to the raised ICP and that the receptors involved here seems to be of alpha2-type.
Blood Pressure ; Inflation, Economic ; Intracranial Pressure* ; Piperoxan ; Prazosin ; Rabbits

The author attempted to clarify the nature of alpha-adrenoceptors in relation to the pressor response to the increased intracranial pressure(ICP) in urethane-anesthetized rabbits, using the epidural balloon method. 1) The blood pressure increased in parallel with the raised ICP which was made by gradual inflation of the balloon. 2) B-HT 920, an alpha2-agonist, which elicited depressor and bradycardiac responses in normal rabbits inhibited markedly the pressor response to the raised ICP. 3) Piperoxan, an alpha2-antagonist, potentiated the pressor response to the raised ICP. 4) Piperoxan antagonized the depressor and bradycardiac responses by B-HT 920 as well as the inhibitory effect of B-HT 920 on the pressor response to the raised ICP. 5) The pressor response to the raised ICP were not affected at all by prazosin, an alpha1-antagonist. 6) Neither the depressor and bradycardiac responses by B-HT 920 itself nor the inhibitory effect of B-HT 920 on the pressor response to the raised ICP were significantly affected by prazosin. It is inferred from these observations that the central alpha-adrenoceptors play an important role in producing the pressor response to the raised ICP and that the receptors involved here seems to be of alpha2-type.
Blood Pressure ; Inflation, Economic ; Intracranial Pressure* ; Piperoxan ; Prazosin ; Rabbits

No abstract available.
Arteries ; Arthroplasty, Replacement, Knee ; Hemorrhage ; Humans ; Inflation, Economic ; Tourniquets ; Transplants

BACKGROUND: Monophasic Action Potential(MAP) recording using contact electrode is very sensitive method to detect the ischemic changes of myocardium. The purpose of this study were to investigate changes of MAP during percutaneous transluminal coronary angioplasty(PTCA) and to evaluate through MAP whether or not a brief episode of ischemia influenced on subsequent ischemic episode during PTCA. Method: MAPs using endocardial contact electrode were recorded dbefore, during the fitst and second inflation and 3 min after PTCA in 7 patients undergoing PTCA. RESULTS: 1) MAP amplitude significantly decreased to 79.1+/-11.0% during the first inflation(p<0.05) and to 86.3+/-9.0% during the second inflation(p<0.05) and recovered to 92.7+/-3.7% at 3 min after PTCA. 2) MAP duration to 90% repolarization(MAPD 90) significantly decreased to 91.4+/-5.1% during the first inflation(p<0.05) and to 95.3+/-3.5% dudring second inflation(p<0.05) and recovered to 97.3+/-2.8% at 3 min after PTCA. 3) Double prodducts showed no significant difference between the first and second inflation. 4) The changes of MAP amplitude and MAP duration during the second inflation was significantly lower than that recorded during the first inflation. CONCLUSION: MAP recording using endocardial contact electode may be safe and very sensitive method to detect the ischemic changes of human endocardium and the lessened MAP changes during the second inflation supports the concept of preconditioning ischemia.
Action Potentials* ; Electrodes ; Endocardium ; Humans ; Inflation, Economic ; Ischemia ; Myocardium