Interrupted time series analysis of vancomycin compared to cefuroxime for surgical prophylaxis in patients undergoing cardiac surgery

The increased incidence of methicillin-resistant Staphylococcus aureus (MRSA), the emergence of community-acquired MRSA, and the continued high incidence of methicillin-resistant Staphylococcus epidermidis have required that certain institutions choose vancomycin for surgical prophylaxis. However, the data supporting the use of vancomycin for surgical prophylaxis are controversial. The purpose of this project was to assess the effect of the change from cefuroxime to vancomycin for surgical site infection (SSI) rates in patients undergoing coronary artery bypass graft (CABG) surgery. The monthly rates of SSIs from 2001 to 2005 were analyzed before and after a change from cefuroxime to vancomycin antibiotic prophylaxis in patients undergoing CABG by using an interrupted time series analysis. Patients who underwent cardiac valve replacement surgery and who had received vancomycin during the entire study period were used as a comparator group. A total of 6,465 patients underwent CABG surgery (n = 4,239) or valve replacement surgery (n = 2,226) during the study period. On average, the monthly SSI incidence rate in patients undergoing CABG surgery decreased by 2.1 cases per 100 surgeries after the switch from cefuroxime to vancomycin (P = 0.042) when patients undergoing valve replacement were used as a comparator group. The change in SSI rates was associated with a decrease in the incidence of infections caused by coagulase-negative Staphylococcus and MRSA isolates, with little change in the incidence of SSIs due to other gram-positive organisms or gram-negative organisms. In institutions with a high incidence of methicillin-resistant Staphylococcus species, this study provides evidence for the clinical efficacy of vancomycin prophylaxis for the prevention of postoperative SSIs in patients undergoing CABG surgery.     

Specific assay of serum lactate dehydrogenase isoenzyme 1 by proteolysis with alpha-chymotrypsin and protein denaturation.

We devised a method for assaying serum lactate dehydrogenase isoenzyme 1 (LD-1) activity specifically by preincubation with alpha-chymotrypsin and guanidine. Cleavage of phenylalanine bonds in the loop of A and B subunits of LD-3, LD-4, and LD-5 isoenzymes (residues 117-119) by incubation with alpha-chymotrypsin for a short time completely inactivated these isoenzymes and partially inactivated LD-2. Addition of guanidine (0.50 mol/L, pH 7.8) to the incubation mixture containing the chymotrypsin completed the inactivation of LD-2. As much as 4000 U/L of LD-2, LD-3, LD-4, and LD-5 were inactivated, whereas LD-1 was affected only slightly. Results by this method (y) correlated well with those by the Roche Isomune immunochemical LD-1 method (x): y = 0.98 x -0.11, r = 0.99 (n = 60). Within-run CVs were 0.5-2.5%. Several common interferents had no effect. In 500 healthy people, serum LD-1 ranged between 66 and 130 U/L, with a mean +/- SD of 88 +/- 15 U/L.     

Factors associated with myocardial infarction after emergency endoscopy for upper gastrointestinal bleeding in high-risk patients: a prospective observational study

BACKGROUND: Because myocardial infarction (MI) after emergency endoscopy for upper gastrointestinal bleeding carries high mortality, we investigated factors associated with procedure-related MI in high-risk patients. METHODS: Consecutive patients with coronary artery disease or age-based risk for coronary artery disease (men, age >45 years; women, >55 years) who underwent emergency endoscopy were enrolled at a single ED. Demographic, laboratory, and outcome data were recorded. Patients fit 1 of 3 groups: MI before endoscopy (pre-panendoscopy [PES] MI), MI after endoscopy (post-PES MI), or non-MI. RESULTS: We enrolled 108 high-risk patients, including 5 (4.6%) with MI diagnosed preendoscopy. Five patients (4.6%) had MIs postendoscopy. Compared with non-MI patients, significantly more post-PES MI patients had heart disease (60.0% vs 12.2%; P = .021), lower systolic pressure on arrival (86.2 +/- 16.6 vs 128.0 +/- 27.2 mm Hg; P = .002), lower diastolic pressure on arrival (50.0 +/- 6.3 vs 69.5 +/- 15.8 mm Hg; P = .003), lower hemoglobin on arrival (6.7 +/- 1.1 vs 9.1 +/- 2.4 g/dL; P = .021), and more persistent shock status preendoscopy (80.0% vs 13.3%; P = .002). There was no significant difference in factors including duration of procedure and rates of recurrent bleeding, postprocedure complication, and mortality. CONCLUSIONS: Heart disease, lower blood pressure or hemoglobin level on arrival, and persistent shock before endoscopy are associated with increased risk for procedure-related MI.     

感染性心内膜炎合并右侧孤立肾换瓣术后护理

目的探讨感染性心内膜炎合并先天性孤立肾患者瓣膜置换术后的护理要点。方法对2012年12月收治的1例行心脏瓣膜置换的感染性心内膜炎合并先天性孤立肾患者,在积极防范术后心脏瓣膜感染基础上,重点就其孤立肾肾功能的保护、监测及相关合并症的护理方法进行回顾总结。结果患者心脏瓣膜置换手术成功,孤立肾。肾功能得到有效保护,痊愈出院。结论对于感染性心内膜炎伴先天性孤立肾患者,换瓣术后应密切观察每小时尿量及24h出入量,早期介入,早期干预,全面保护其肾脏功能。     

Diagnosis of perioperative myocardial infarction by considering relationship of postoperative electrocardiogram changes and enzyme increases after coronary bypass operation

We report the results of enzyme determinations in sera from 88 patients, 65 of whom showed inconspicuous reconvalescence, 14 who had myocardial infarction within 24 h (MI 1) after bypass surgery, and nine with myocardial infarction between 24 and 48 h postoperatively (MI 2). We wanted to determine whether the consequent measurement of activities of total creatine kinase (CK), CK isoenzyme MB (CK-MB), lactate dehydrogenase, alpha-hydroxybutyrate dehydrogenase, and aspartate aminotransferase, conducted as a part of routine laboratory diagnostics, provided meaningful information for diagnosing infarcts besides that obtained from the electrocardiogram. The postoperative mean values of the enzyme activities in blood were significantly different among the three groups; however, only a combined evaluation of CK and CK-MB by means of a discriminant analysis allowed the prediction of MI (sensitivity: MI 1 = 98.5%, MI 2 = 95.4%; specificity: MI 1 = 71.4%, MI 2 = 81.8%). CK greater than 600 U/L or CK-MB greater than 45 U/L supports the diagnosis of acute MI.     

Clinical evaluation of an automated chemical inhibition assay for lactate dehydrogenase isoenzyme 1

We evaluated an automated assay for lactate dehydrogenase (LD; EC 1.1.1.27) isoenzymes, supplied by Boehringer Mannheim Diagnostics (BMD) and based on selective chemical inhibition of non-LD-1 isoenzymes by guanidine thiocyanate. Results were compared with the Roche Isomune LD-1 method. The Hitachi 717 analyzer was used to measure enzyme activity for both procedures in 229 serum samples. One hundred specimens were also analyzed by the Helena rapid electrophoresis (REP) method. We determined the limit of linearity of the BMD method to be about 1200 U of LD-1 per liter. The analytical correlation of BMD (y) with Isomune (x) yielded y = 1.0x + 0.5 U/L, r = 0.997, Sy/x = 16.9 (range 20-1397 U/L). The regression equation for BMD vs REP was y = 1.1x + 7.2% (r = 0.800, Sy/x = 7.4, range 14-83%). Average values for within-run precision for low (38 U/L), medium (180 U/L), and high (865 U/L) controls were 4.1%, 1.0%, and 0.5%, respectively (16 trials of six each). The average values for run-to-run precision were 4.1%, 1.7%, and 1.1%, respectively, for these controls (n = 16). We used receiver-operating characteristic curves to determine optimum decision limits. Using an LD-1 cutoff of 40% of total LD, we obtained a clinical sensitivity of 97-100% and a specificity of 95% when blood was collected during the optimum interval, 24-48 h after the onset of chest pain. We conclude that the BMD LD-1 assay is equivalent to the immunochemical and electrophoretic assays for measuring the LD-1 isoenzyme.     

心脏瓣膜置换术患者血浆纤维蛋白原水平动态变化监测的临床价值

目的探讨心脏瓣膜置换术患者血浆纤维蛋白原水平动态监 测的临床价值。方法选取2017年12月～2018年3月就诊于北部战区 总医院心血管外科的20例心脏瓣膜置换术患者(除外并发肝肾功能障碍者),根据手术进程分 为术前24 h(对照组)、术后12,24,48 h和术后72 h五组,提取血液样本采用Clauss法检测 患者血浆中纤维蛋白原含量,应用配对样本 t 检验进行统计学分析,判断纤维蛋白原水 平动态变化的临床价值。结果手术前24 h纤维蛋白原含量为3.55 ±1.042 g/L。术后12 h纤维蛋白原含量4.87±1.050 g/L。术后24 h纤维蛋白原含量的 平均值为6.14±1.428 g/L。术后48 h纤维蛋白原含量的平均值为6.43±1.744 g/L。术 后72 h纤维蛋白原含量的平均值为5.89±2.094 g/L。术后各时间点检测的纤维蛋白原含 量均明显高于术前,差异均有统计学意义( t=4.445～7.063,均P <0.05)。术后24 h ～72 h纤维蛋白原含量明显高于术后12 h,差异有统计学意义( t=2.317～6.146,均P <0.05)。术后48 h至72 h纤维蛋白原含量与术后24 h相比变化不大,差异无统计学意义( t=0.797～1.485,均P >0.05)。术后72 h纤维蛋白原含量明显低于术后48 h,差异有统 计学意义( t=2.416,P <0.05)。结论心脏瓣膜置换术后纤维 蛋白原水平升高,应用低分子肝素及华法林抗凝治疗后纤维蛋白原水平降低。     

Total and unbound Cortisol-, progesterone-, oestrone- and transcortin-binding activities in sera from patients with myocardial infarction: evidence for differential responses of good and bad prognostic cases

Day-of-admission sera from myocardial infarction patients (MI) and patients with cardiopathies other than MI (non-MI) were analysed for total and unbound cortisol (F), progesterone (P4), oestrone (E1), and corticosteroid binding activities (CBG). The MI who survived (n = 28) showed high increases of F, P4 and E1 compared to healthy controls. By contrast, the MI who died within 10 days of admission (n = 6) had unchanged F and less increased P4 and E1 than survivors. The non-MI (n = 6) had higher F and E1 than controls but normal P4. The unbound steroids were increased in all patients: however, the MI who died showed much smaller rises than survivors (P less than 0.001 for unbound F and E1 increases in survivors vs. deceased). The CBG activity was in all MI lower than in normals (P less than 0.001) but unchanged in non-MI. These results are discussed in terms of the potential significance of unbound plasma steroids as predictors of MI severity.     

Quantification of lactate dehydrogenase-1 in serum with use of an M-subunit-specific monoclonal antibody

We have developed a rapid, one-step assay for measuring lactate dehydrogenase-1 (LD-1) activity in serum after extraction of LD-2, LD-3, LD-4, and LD-5 isoenzymes by an immobilized M-subunit-specific monoclonal antibody (D.8.1). In the assay, 100 microL of serum is mixed with 50 microL of a suspension of 0.8-micron-diameter latex particles coated with 30 micrograms of the monoclonal antibody D.8.1, then incubated at room temperature for 5 min. The latex particles, to which LD-2 through LD-5 are bound, are pelleted by centrifugation for 2 min at 12,000 X g, and the LD-1 activity is measured kinetically in the supernatant fluid. We optimized the assay for antibody immobilization, antibody concentration, and time and temperature of incubation. Serum bilirubin concentrations up to 0.33 g/L (0.56 mmol/L) did not interfere in the assay. Hemolysis interfered solely through LD-1 released from erythrocytes. The within-assay CV for low-concentration quality-control material (LD-1 33 U/L) was 3.5% (n = 9) and for high-concentration material (LD-1 185 U/L) was 1.9% (n = 8); the between-assay CVs for the two materials were 6.1% (n = 9) and 2.5% (n = 10), respectively. The LD-1 activity measured in 98 samples by our assay compared well with a two-step polyclonal antibody-based assay (Isomune-LD, Roche Diagnostic Systems; r = 0.998) and with an electrophoretic method (Paragon, Beckman Instruments; r = 0.956).     

Does off‐pump coronary artery bypass surgery reduce secretion of plasminogen activator inhibitor‐1?

Prior studies showed that postoperative increase in plasminogen activator inhibitor-1 (PAI-1) levels is associated with an increased risk of graft occlusion after coronary artery bypass surgery (CABG). This prospective study aimed to compare the changes of PAI-1 antigen levels after off-pump and on-pump CABG. Forty-four patients admitted for elective CABG were randomised to on-pump (n=22) or off-pump (n=22) surgery. Serum samples were collected for estimation of PAI-1 and tissue plasminogen activator (t-PA) antigen levels preoperatively and 2 h after the operation. The groups were similar in terms of age, weight, gender ratio and extent of coronary disease, left ventricular function and number of grafts per patient. Fibrinogen and t-PA levels increased postoperatively in both the groups when compared with baseline values. After operation, statistical analysis revealed that increase of PAI-1 values was higher in off-pump group (44.1+/-9.1 vs. 25.3+/-6.9) than on-pump group (37.2+/-5.5 vs. 27.3+/-7.8, p=0.002). This study shows that increase in PAI-1 antigen values in patients who undergo off-pump (beating heart) CABG is significantly higher than in those who undergo conventional CABG with cardiopulmonary bypass.     

Tolerance of vancomycin for surgical prophylaxis in patients undergoing cardiac surgery and incidence of vancomycin-resistant enterococcus colonization

BACKGROUND: In 2001, vancomycin replaced cefuroxime for antibiotic prophylaxis in patients undergoing cardiac surgery at our institution due to high rates of surgical site infections caused by methicillin-resistant Staphylococcus spp. However, few data supported the use of vancomycin for surgical prophylaxis. OBJECTIVE: To determine the tolerance of vancomycin for antibiotic prophylaxis and incidence of vancomycin-resistant Enterococcus (VRE) in cardiac surgery patients. METHODS: In 2 separate studies, we assessed the adverse effects in patients given perioperative vancomycin (study 1) and the incidence of VRE in patients given perioperative vancomycin (study 2). Study 1 was a prospective cohort study of patients undergoing coronary artery bypass graft (CABG) or valve replacement surgery given vancomycin (1 dose preoperatively/2 doses postoperatively) for antibiotic prophylaxis between October 2003 and December 2004. Patients were assessed for tolerance to the antibiotic regimen. In study 2, cardiac surgery patients receiving perioperative vancomycin were screened for VRE before therapy and at day 7 of hospitalization. VRE was detected using standard microbiologic procedures. RESULTS: In study 1, 1161 patients (CABG = 75%; valve = 19%; both = 6%) were evaluated. All patients but one (99.9%) were prescribed preoperative vancomycin. Therapy was changed for 34 (2.9%) patients, of which 20 changes were due to physician preference for another antibiotic. The only toxicity that required a change in the vancomycin regimen was red man's syndrome, which was experienced by 9 (0.8%) patients. Four patients did not receive a second postoperative dose due to prior renal insufficiency. Patients were most commonly switched to cefuroxime (n = 26), linezolid (n = 2), cefepime (n = 2), gatifloxacin, cefazolin, levofloxacin, or ceftriaxone (n = 1, each). In study 2, 100 patients were screened for the emergence of VRE colonization. No patient was VRE positive at baseline and 4 (4%) were positive at day 7. CONCLUSIONS: Surgical antibiotic prophylaxis with vancomycin was reasonably well tolerated in CABG and valve replacement surgery, with a 4% incidence of VRE colonization.     

Rifampin blood and tissue levels in patients undergoing cardiac valve surgery.

Single 600-mg capsules of rifampin were given orally to 26 patients as prophylaxis during cardiac valve replacement. Antibiotic concentrations were measured in blood (serum or plasma) and tissue (excised cardiac valve). The serum or plasma levels of rifampin in 18 patients who ingested this drug 2 h before they received preoperative opiates and anticholinergics intramuscularly were not significantly different from the levels in four normal volunteers who received the drug. These levels were 15.9 +/- 6.5 micrograms/ml (mean +/- standard deviation) 2 h after drug administration, 7.1 +/- 4.3 micrograms/ml 8 h after drug administration and 2 h after a mean of 1.4 h on cardiopulmonary bypass, and 1.6 +/- 1.6 micrograms/ml 24 h after drug ingestion. The valve tissue level was 3.8 +/- 2.7 micrograms/g (mean +/- standard deviation; n = 10). This value was 65% of the simultaneous serum and plasma levels and 31% of the peak serum and plasma levels. Eight patients who were given rifampin at the same time that they received other preoperative medications had significantly lower blood levels than the 18 patients who received rifampin 2 h earlier (P less than 0.001). No rifampin was detected in valves from seven of these patients. Decreased rifampin absorption due to simultaneous administration with opiates and anticholinergics was the probable reason for the low plasma and serum levels observed. These data suggest that, if properly dosed, rifampin administered orally gives high blood and valve tissue levels, which are affected minimally by cardiopulmonary bypass in patients undergoing cardiac valve surgery.     

Penetration of ofloxacin into heart valves, myocardium, mediastinal fat, and sternal bone marrow in humans.

Ofloxacin penetration into heart tissue (valve and myocardium), mediastinal fat, and sternal bone marrow was the object of a prospective nonrandomized study. Thirty-six patients undergoing mitral and/or aortic valve replacement were included. Patients were divided into two groups of 18 patients each. Group 1 patients were administered a single 400-mg intravenous dose of ofloxacin over a 30-min period upon anesthesia (n = 6) or at 1 h (n = 6) or 6 h (n = 6) prior to surgery. Group 2 patients received a 200-mg oral dose of ofloxacin every 12 h during the 48 h preceding surgery. In this group, the final dose of ofloxacin was administered 3 h (n = 9) or 8 h (n = 9) before anesthesia. Plasma and tissue ofloxacin concentrations were assayed by high-pressure liquid chromatography. In group 1 patients, the peak level in plasma was 15.9 +/- 2.5 micrograms/ml. Peak ofloxacin levels in tissue were reached by hour 1 and were 8.89 +/- 2.16 micrograms/g in myocardium and 5 +/- 0.75 micrograms/g in heart valves. A significant decrease in ofloxacin levels in heart valve tissue and sternal bone marrow was observed after hour 3. Nevertheless, ofloxacin myocardial, heart valve, and sternal bone marrow levels remained higher than the MICs for the usually susceptible pathogens for at least 3 h. In group 2 patients, myocardial levels were long lasting (6.46 +/- 1.92 micrograms/g [4 to 8 h] and 5.92 +/- 0.95 micrograms/g [8 to 12 h]) and remained higher than those observed in the other tissues over the entire study period. A progressive but insignificant decrease in ofloxacin heart valve levels was observed (from 2.46 +/- 0.40 micrograms/g [4 to 8 h] to 1.57 +/- 0.22 micrograms/g [8 to 12 h]). In both groups, concentration in mediastinal fat were lower and tended to decrease with time. These were 1.83 +/- 0.61 micrograms/g with the first hour and 0.85 +/- 0.43 micrograms/g between hours 8 and 12 in group 1 and 1.74 +/- 0.52 micrograms/g between hours 4 and 8 and 0.67 +/- 0.11 micrograms/g between hours 8 and 12 in group 2. In conclusion, satisfactory diffusion of ofloxacin into heart tissue seems to favor use of the drug in the treatment of bacterial endocarditis due to susceptible pathogens. Furthermore, the progressively decreasing concentrations observed in heart valve and sternal bone marrow and the poor levels achieved in mediastinal fat suggest the need for renewing injection 3 h following initial infusion if the drug is used as an antibiotic prophylactic agent during cardiovascular surgery.     

Preoperative 24-hour urine amount as an independent predictor of renal outcome in poor cardiac function patients after coronary artery bypass grafting

PURPOSE: To investigate the incidence and the main pre-operative risk factors for the development of acute renal failure (ARF) in triple vessels coronary artery bypass grafting (CABG) with special reference to a subset of patients with poor cardiac function (ejection fraction <50%). PATIENTS: The study included the patients (n = 66) requiring CABG from January 1, 1995 to January 1, 2002 in a medical center. RESULTS: A high percentage (84.8%) of patients developed ARF and 57.6% of patients received hemodialysis (HD). Preoperative variables significantly associated with the development of ARF included increased age, increased preoperative serum creatinine, decreased preoperative 24-hour urine output and accepted emergent CABG. By the logistic multivariate regression model, increased age (OR = 1.16), preoperative serum creatinine (OR = 3.58,), decreased preoperative 24-hour urine amount (OR = 0.99,) and emergent CABG (OR = 2.01) were independently associated with ARF. As for the need for HD, those factors including, preoperative serum creatinine (2.11 +/- 1.13 v 3.08 +/- 1.67 mg/dL) and preoperative 24-hour urine output (1358.6 +/- 745.9 v 755.2 +/- 572.1 mL/day) were significantly associated with requirement of dialysis. Using multivariate logistic regression, the significant risk factors independently associated with dialysis were preoperative serum creatinine (OR = 1.34) and preoperative 24-hour urine output (OR = 0.99). Patients with non- oliguric renal failure had significantly greater chance of recovering their renal function after cardiac surgery compared to those with oliguria (36.9% v 10.0%, P <.05). CONCLUSION: Preoperative 24-hour urine amount and pre-operative serum creatinine can provide valuable information for predicting the likelihood of developing acute renal failure and requiring dialysis in this subgroup of patients.     

Automated kinetic assay of angiotensin-converting enzyme in serum

We have developed and validated an automated kinetic method for angiotensin-converting enzyme (EC 3.4.15.1) on the Olli C + D analyzer, modified from that of Ronca-Testoni (Clin Chem 1983;29:1093-6) with N-[3-(2-furyl)-acryloyl]-L-phenylalanylglycylglycine used as substrate. We have determined appropriate reaction conditions for the assay, verified the principal analytical reliability criteria (repeatability, reproducibility, sensitivity), and established normal reference intervals (mean +/- SD) for the enzyme's activity, using serum of normal adults (100 +/- 35 U/L, n = 150), newborns (130 +/- 27 U/L, n = 10), women taking oral contraceptives (103 +/- 30 U/L, n = 10), smokers (109 +/- 38 U/L, n = 27), and patients with sarcoidosis (220 +/- 48 U/L, n = 15).     

Elevation of serum cerebral injury markers correlates with serum choline decline after coronary artery bypass grafting surgery.

The aims of this study were to determine circulating choline status and its relationship to circulating levels of S-100beta protein and neuron-specific enolase, biochemical markers of cerebral injury and cognitive decline, after coronary artery bypass grafting (CABG) surgery. Preoperatively, patients scheduled for off-pump or on-pump CABG surgery had serum concentrations of 12.0+/-0.2 and 11.7+/-0.4 micromol/L free choline and 2640+/-65 and 2675+/-115 micromol/L phospholipid-bound choline, respectively. Serum free and bound choline levels decreased by 22-37% or 34-47% and 16-36% or 31-38% at 48 h after off-pump or on-pump surgery, respectively. Serum S-100beta and neuron-specific enolase increased from preoperative values of 0.083+/-0.009 and 6.3+/-0.2 microg/L to 0.405+/-0.022 and 11.4+/-0.8 microg/L, respectively, at 0 h postoperatively and remained elevated for 48 h after off-pump surgery. Serum free and bound choline concentrations were inversely correlated with the concentrations of S-100beta (r=-0.798; p<0.001 and r=-0.734; p<0.001) and neuron-specific enolase (r=-0.840; p<0.001 and r=-0.728; p<0.001). In conclusion, CABG surgery induces a decline in serum free and phospholipid-bound choline concentrations. The decreased serum choline concentrations were inversely correlated with the elevated levels of circulating cerebral injury markers. Thus, a decline in circulating choline may be involved in postoperative cognitive decline.     

Diagnostic efficiency of four lactate dehydrogenase isoenzyme-1 ratios in serum after myocardial infarction

We compared the diagnostic efficacy of the ratios LD-1/LD-2, LD-1/LD-3, LD-1/LD-4, and LD-1/LD-5 in 69 documented cases of myocardial infarction. We used 149 patients with congestive heart failure and 67 patients with nonmyocardial infarct as controls. We used a computer program to produce receiver-operating characteristic curves, decision threshold plots, and likelihood ratios for these LD ratios at 6-h intervals up to 108 h after the onset of chest pain or hospital admission. All ratios in the myocardial infarction cases peaked around 36 h after the onset of chest pain, while those for the nonmyocardial and congestive cardiac failure cases did not change over the 108-h period. In all patients with infarctions, LD-1/LD-4 and LD-1/LD-5 increased by 1.7 times (when LD-1 was less than 40%) and 3.4 times (when LD-1 was greater than 40%), respectively, over control values. Optimum decision threshold values were obtained at 13-24 h (LD-1/LD-5), 31-36 h (LD-1/LD-4 and LD-1/LD-3), and 55-60 h (LD-1/LD-2) after onset of symptoms. The highest likelihood ratio was obtained with the LD-1/LD-4 ratio; therefore, we suggest that this is a better diagnostic test for myocardial infarction than LD-1/LD-2.     

Clinical evaluation of the first medical whole blood, point-of-care testing device for detection of myocardial infarction

BACKGROUND: Validation of whole blood, point-of-care testing devices for monitoring cardiac markers to aid clinicians in ruling in and ruling out myocardial infarction (MI) is necessary for both laboratory and clinical acceptance. METHODS: This study evaluated the clinical diagnostic sensitivity and specificity of the First Medical Cardiac Test device operated by nursing and laboratory personnel that simultaneously measures cardiac troponin I (cTnI), creatine kinase (CK) MB, myoglobin, and total CK on the Alpha Dx analyzer in whole blood for detection of MI. Over a 6-month period, 369 patients initially presenting to the emergency department with chest pain were evaluated for MI using modified WHO criteria. Eighty-nine patients (24%) were diagnosed with MI. RESULTS: In whole blood samples collected at admission and at 3- to 6-h intervals over 24 h, ROC curve-determined MI decision limits were as follows: cTnI, 0.4 microgram/L; CKMB, 7.0 microgram/L; myoglobin, 180 microgram/L; total CK, 190 microgram/L. Based on peak concentrations within 24 h after presentation, the following sensitivities (+/- 95% confidence intervals) were found: cTnI, 93% +/- 5.5%; myoglobin, 81% +/- 9.7%; CKMB, 90% +/- 6.3%; total CK, 86% +/- 7.5%. Sensitivities were maximal at >90% for both cTnI and CKMB at >12 h in MI patients, without differences between ST-segment elevation and non-ST-segment elevation MI patients. CONCLUSIONS: The First Medical point-of-care device provides cardiac marker assays that can be used by laboratories and clinicians in a variety of hospital settings for ruling in and ruling out MI.     

Increased lactate dehydrogenase in serum in measles infection

We determined lactate dehydrogenase (LD; EC 1.1.1.27) in serum from 75 sequential measles patients and 105 control patients. In the measles patients, LD was increased to 1147.9 +/- 43.8 (mean +/- SE) U/L, markedly more than in the control group (517.2 +/- 15.0 U/L, p less than 0.001). Both LD-3 and LD-4 isoenzymes were increased, but the concentration of LD-5 was normal. Patients with high LD values (greater than 1500 U/L) had longer hospital stays than did those with lower values (p less than 0.01). Our results suggest that increased LD in serum is a common finding in measles infection and presumably originates from lymphocytes.     

Changes in serum CK-MB mass after coronary artery bypass surgery

We assessed the release of creatine kinase MB as both mass and activity during the postoperative period following cardiac surgery. CK-MB mass was determined by enzyme immunoassay using reagents obtained from Hybritech. CK-MB activity was determined both by agarose electrophoresis and by an immunochemical method. Fifty-five patients who underwent coronary artery bypass surgery and 52 control subjects who had orthopedic surgery were selected for study. Serial serum samples were collected following surgery and total LD, CK, AST, LD-1, CK-MB mass, and CK-MB activity determined. Results were compared to each other and to surgical parameters. All patients exhibited significant CK-MB mass and activity after surgery and peak serum levels were 6-94 micrograms/L and 12-84 U/L, respectively. CK-MB mass correlated with CK-MB activity on paired samples (r = 0.94). Total AST and CK activities correlated with CK-MB mass (r = 0.60, and 0.63, respectively). Peak levels of CK-MB mass correlated significantly with peak MB activity (r = 0.88), peak LD-1 (r = 0.62), peak AST (r = 0.71), and time on pump (r = 0.54). Similar correlations were also seen between peak CK-MB activity and these parameters. No relationship could be identified between extent of CK-MB mass release and number of grafts, degree of hypothermia, or minimum PaO2. The time course of CK-MB mass release exhibited 85% concordance with CK-MB activity.(ABSTRACT TRUNCATED AT 250 WORDS)