INTRODUCTIONThe relationship between electrocardiograph (ECG) changes and troponin levels after the emergency orthopaedic surgery are not well characterised. The aim of this study was to determine the correlation between ECG changes (ischaemia or arrhythmia), troponin elevations perioperatively and cardiac complications.

MATERIALS AND METHODSOne hundred and eighty-seven orthopaedic patients over 60 years of age were prospectively tested for troponin I and ECGs were performed on the fi rst 3 postoperative mornings or until discharge.

RESULTSThe incidences of pre- and postoperative troponin elevation were 15.5% and 37.4% respectively, the majority were asymptomatically detected. Most of the patients who sustained a troponin rise did not have any concomitant ECG changes (51/70 or 72.9%). Postoperative ECG changes were noted in 18.4% (34/185) and of those with ECG changes, slightly more than half (55.9%) had a troponin elevation. Most ECG changes occurred on postoperative day 1 and were non-ST elevation in type. ECG changes occurred more frequently with higher troponin levels. Postoperative troponin elevation (P = 0.018) and not preoperative troponin level (P = 0.060) was associated with ECG changes on univariate analysis. Two premorbid factors were predictors of postoperative ECG changes using multivariate logistical regression; age [odds ratio (OR), 1.05; 95% CI, 1.005 to 1.100, P = 0.029) and sex OR, 2.4; 95% CI, 1.069 to 5.446, P = 0.034). Twenty patients sustained postoperative cardiac complications; 9 (45%) were associated with ECG changes and 16 (80%) with postoperative troponin elevation. Pre- or postoperative troponin elevation better predicted cardiac complications compared with preoperative ECG changes.

CONCLUSIONElectrocardiograph changes do not necessarily accompany troponin elevations after the emergency orthopaedic surgery but are more likely to have higher troponin levels. The best predictor of postoperative cardiac complications is troponin elevation.

Aged ; Aged, 80 and over ; Arrhythmias, Cardiac ; blood ; diagnosis ; etiology ; mortality ; Biomarkers ; blood ; Electrocardiography ; Female ; Humans ; Logistic Models ; Male ; Middle Aged ; Multivariate Analysis ; Myocardial Ischemia ; blood ; diagnosis ; etiology ; mortality ; Orthopedic Procedures ; Postoperative Complications ; blood ; diagnosis ; etiology ; mortality ; Postoperative Period ; Preoperative Period ; Prospective Studies ; ROC Curve ; Risk Factors ; Single-Blind Method ; Troponin I ; blood

BACKGROUND: To evaluate the feasibility of a micro-image based finite element model to determine the efficacy of sequential treatments on the bone quality in a rat osteoporosis model. METHODS: Rat osteoporosis and treated osteoporosis models were established with the bone loss, restore and maintain concept. Thirty Sprague-Dawley rats were used in this study. A sham operation or ovariectomy was performed at 20 weeks after birth, which was followed by the respective sequential trials as follows: (1) sham-operation only, (2) ovariectomy only, (3) ovariectomized rats with parathyroid hormone maintenance, (4) ovariectomized rats treated with PTH for 5 weeks and then withdrawal, (5) ovariectomized rats treated with PTH for 5 weeks and then with 17 beta-estradiol, and (6) ovariectomized rats treated with parathyroid hormone for 5 weeks and then treated with zoledronate. The histomorphometry indices were determined using the micro-images from a micro-computed tomogram. Finite element analysis was carried out to determine the mechanical properties (Stiffness and Young's modulus) of the vertebra bodies. The differences in properties between the groups were compared using ANOVA and a Bonferroni's multiple group comparison procedure. RESULTS: The histomorphometry and mechanical properties were significantly better in groups (3) and (6) than in the groups (1) and (2) (p < 0.05). The stiffness (sigmas) and Young's modulus (E) was highest in group (3) following by group (6). CONCLUSIONS: Finite element analysis based on micro-images provides a useful tool that reflects the changes in micro-structural and mechanical properties of a rat vertebral body with the bone loss, restore and maintain concept.
Analysis of Variance ; Animals ; Female ; *Finite Element Analysis ; Osteoporosis/*pathology/*radiography ; Rats ; Rats, Sprague-Dawley ; Spine/*pathology/*radiography ; Tomography, X-Ray Computed/methods ; X-Ray Microtomography/*methods

Plasma pH can be altered during pregnancy and at labor. Membrane excitability of smooth muscle including uterine muscle is suppressed by the activation of K+ channels. Because contractility of uterine muscle is regulated by extracellular pH and humoral factors, K+ conductance could be connected to factors regulating uterine contractility during pregnancy. Here, we showed that TASK-2 inhibitors such as quinidine, lidocaine, and extracellular acidosis produced contraction in uterine circular muscle of mouse. Furthermore, contractility was significantly increased in pregnant uterine circular muscle than that of non-pregnant muscle. These patterns were not changed even in the presence of tetraetylammonium (TEA) and 4-aminopyridine (4-AP). Finally, TASK-2 inhibitors induced strong myometrial contraction even in the presence of L-methionine, a known inhibitor of stretchactivated channels in myometrium. When compared to non-pregnant myometrium, pregnant myometrium showed increased immunohistochemical expression of TASK-2. Therefore, TASK-2, seems to play a key role during regulation of myometrial contractility in the pregnancy and provides new insight into preventing preterm delivery.
4-Aminopyridine ; Acidosis ; Animals ; Contracts ; Female ; Hydrogen-Ion Concentration ; Lidocaine ; Membranes ; Methionine ; Mice ; Muscle, Smooth ; Muscles ; Myometrium ; Plasma ; Pregnancy ; Quinidine ; Relaxation ; Uterine Contraction ; Uterus