An analysis of the factors producing multiple ventricular arrhythmias during pulmonary artery catheterization.

BACKGROUND: The development of arrhythmias during placement of a pulmonary artery catheter (PAC) is common. AIMS: This study was designed to examine factors influencing development of ventricular arrhythmias in adult patients undergoing cardiovascular operations during the catheter placement. SETTINGS AND DESIGNS: Prospective, observational, cohort study. METHODS: We prospectively studied 174 patients undergoing cardiovascular operations. A PAC was inserted through the right internal jugular vein by staff anesthesiologists. Electrocardiography tracings were recorded as the catheter was advanced from the right atrium to the pulmonary artery. Arrhythmias were classified as absent, single, or multiple (two or more consecutive) ventricular arrhythmias. We examined risk factors to produce ventricular arrhythmias during the placement. STATISTICAL ANALYSIS: The data were analyzed using logistic regression analysis to assess factors for the occurrence of ventricular arrhythmias after univariate analyses. RESULTS: Ventricular arrhythmias (single and multiple) occurred in 149 patients (85.6%) and multiple arrhythmias were observed in 78 patients (44.8%). There were no factors to facilitate the ventricular arrhythmias (single and multiple), whereas it showed that valvular diseases (P = 0.049) and the placement time (P < 0.001) are significant factors to produce multiple arrhythmias. CONCLUSION: Both valvular diseases and long placement time were significant risk factors to produce multiple ventricular arrhythmias during placement of a PAC.

Mouthguard retention: is design or accuracy of fit more critical?

AIM: To examine the influence of the accuracy of fit on mouthguard retention in relation to mouthguard outline location. MATERIALS AND METHODS: Mouthguards were fabricated on a fully dentate maxillary cast with 4-mm thick ethylene vinyl acetate sheets using a well-dried cast (VD) and on a wet cast (VW) with a vacuum-forming machine. Mouthguards were also made with a pressure-forming machine (P). The mouthguard outline was set at 4 mm from the cervical margin (control, C), the palatal outline was set at the cervical margin (Pa), and the buccal outline was extended to the buccal fold (Bu). A dislodging force perpendicular to the occlusal plane was applied at the first molar on the universal testing machine. Results were analyzed using ANOVA with Scheffe's test (P < .05). RESULTS: Using the VW, the retentive forces were statistically smaller at Pa compared to Ca or Bu (C: 58 +/- 17 gf, Pa: 36 +/- 7 gf , Bu: 50+/-8 gf) (P < .05). There were no statistical differences between VD (C: 116+/-27 gf, Pa: 86+/-15 gf, Bu: 92+/-7 gf) and group P (C: 133+/-31 gf, Pa: 139+/-24 gf, Bu: 136+/-17 gf). CONCLUSIONS: The results indicate that mouthguard retention is closely related to the accuracy of fit at the cervical undercut area rather than the outline location.

Ciliated hepatic foregut cyst with obstructive jaundice.

Ciliated hepatic foregut cysts (CHFCs) are rare congenital cystic lesion that are most often solitary, unilocular, and located in the subcapsular region of the medial segment of the left hepatic lobe. The mucoid fluid contents affect imaging studies and often make definitive diagnosis difficult. CHFCs are usually asymptomatic and found incidentally. We report a 69-year-old female patient with a CHFC causing obstructive jaundice, which was difficult to differentiate from a biliary cystic neoplasm. A well-defined cystic lesion measuring 25 mm in diameter was located in the porta hepatis region. The lesion was densely adherent to the left and right hepatic ducts, riding on the bifurcation, and the common hepatic duct was extrinsically compressed. An extended left hepatectomy was performed. A diagnosis of CHFC was made on the basis of typical histological findings. CHFC should be included in the differential diagnosis for cystic lesions of the liver.

Anterior palatal mouthguard margin location and its effect on shock-absorbing capability.

The purpose of this study was to evaluate the influence of a mouthguard's (MGs) anterior palatal margin location on its shock absorbing capability. A simulation study was conducted on a maxillary phantom model with maxillary teeth, bone, and soft tissue. Miniature strain gauges were attached to the labial and palatal surfaces of the right central incisor as well as the bone surface on the palatal side. MGs were made with ethylene vinyl acetate sheets, with thickness of 2.0, 3.0, and 4.0 mm, using a pressure-forming machine. The locations of the anterior palatal MG margins were set at 4.0, 2.0, and 0 mm from the cervical margin in three experimental configurations. The control situation was without a MG. A calibrated 7N of shock was applied to the middle portions of the labial and palatal surfaces of the central incisor. The amount of tooth deflection was evaluated. The results were analyzed with one-way anova accompanied by the Scheffe's test and multiple regression analysis (P<0.05), designating the strain as the dependent value. The results indicated that the thickness rather than the location of the anterior palatal margin of the MG has a significant influence on the reduction of tooth deflection against a horizontal blow.