Factors predicting stomal wound closure infection rates

Background

Stoma closure is associated with high wound infection rates. The aim of this study was to evaluate risk factors for infection rates in such wounds, with particular emphasis on assessing the importance of the stomal wound closure technique.

Methods

A retrospective analysis of 142 patients who had undergone ileostomy or colostomy closure between 2002 and 2011 was performed. Postoperative outcome as measured by wound infection rate was recorded. Three different closure techniques were identified: primary closure (PC), primary closure with Penrose drain (PCP) and purse-string circumferential wound approximation technique (PSC). Other factors such as age, sex, ASA score, type of prophylactic antibiotics used, diabetes, smoking and obesity were also analysed. All other techniques were excluded.

Results

Our series consisted of 142 stomal closures (90 ileostomy and 52 colostomy closures). The patients had a median age of 63.5 years with an interquartile range of 50.1–73.2 years. The overall wound infection rate was 10.7 %. PC, PCP and PSC were associated with wound infection rates of 17.9, 10.5 and 3.6 %, respectively. Compared to PSC, PC and PCP were associated with significantly higher wound infection rates (p = 0.027 and p = 0.068, respectively). Obesity was a significant risk factor for wound infection (p = 0.024). Use of triple-agent antibiotics prophylactically had a protective effect on the infection rate (p = 0.012).

Conclusions

To reduce stomal wound closure infection rates, we recommend institution of closure techniques other than PC with or without a drain. Risk factors such as obesity should be addressed, and prophylactic triple antibiotics should be administered.     

Mouse spleen lymphoblasts generated in vitro. Their replication and differentiation in vitro

Mouse spleen lymphoblasts induced with lipopolysaccharide and fetal calf serum were obtained in high yield and purity in their first proliferative cell cycle by floatation in dense bovine plasma albumin columns (3). The blasts were maintained in vitro for 3 more days. The cultures were examined in bulk on each day, and in addition, those cells in S phase initially were tagged with [(3)H]thymidine and followed continuously in vitro. Grain count dilution data indicated that most blasts divided but twice over a 2- to 3-day interval in vitro. [(3)H]Thymidine pulse radiolabeling and flow microfluorometry suggested that at least 50-70 percent of the proliferating blasts withdrew from proliferative activity after 2-3 days of culture. Morphologic studies demonstrated that lymphoblasts persisted as such for 1-2 days in vitro and then matured into typical plasma cells. Many of the blastprogeny had small nuclei and considerable basophilic cytoplasm on Giemsa-stained cell smears; abundant rough endoplasmic reticulum by electron microscopy; and readily detectable cytoplasmic Ig by immunocytochemistry. Reversion of blasts to small lymphocytes could not be detected; however, some blasts persisted even after 3 days of culture. The viability of the cultured lymphoblast was followed by initially tagging the cells with [(3)H]thymidine as well as several other techniques. Little cell death was documented during the first day of culture. The number of labeled progeny increased twofold whereas the grain count halved. But 40- 50 percent of the cell-associated label was lost during each of the second and third days, and fewer labeled progeny than predicted by grain count dilution were identified. The culture medium could not be implicated in this loss of lymphoblast progeny, and we suggest that the maturation of the lymphoblast to a short-lived plasma cell was responsible. Therefore mitogen-stimulated B blasts seem to mature into typical plasma cells after just two cycles of cell division. The plasma cells resemble those produced in situ during an immune response in their cytologic features, withdrawal from active proliferative activity, and short life-span.     

Tumor cell anti-oxidant defenses. Inhibition of the glutathione redox cycle enhances macrophage-mediated cytolysis

The basis of resistance to oxidative injury was studied in six murine tumor cell lines that differed 54-fold in their resistance to enzymatically generated H(2)0(2). The tumors varied 56.7-fold in their specific activity of catalase, 5.3-fold in glutathione peroxidase (GPO), 3.3-fold in glutathione reductase (GR), and 2.7-fold in glutathione. There was no correlation among the levels of the three enzymes, and tumor cell resistance to lysis by H(2)0(2). However, the logarithm of the flux of H(2)0(2) necessary to cause 50 percent lysis of the tumor cells correlated with their content of glutathione (r = 0.91). The protective role of glutathione was analyzed by blocking GR and GPO, the catalysts of the glutathione redox cycle. This was facilitated by the demonstration that the anti-neoplastic agent 1,3-bis-(2- chloroethyl)-l-nitrosourea (BCNU) was a potent inhibitor of GR in intact tumor cells. BCNU inactivated tumor cell GR with a 50 percent inhibitory dose of 11 μM and a t(l/2) of inhibition of 30 s. Complete inhibition of GR was attained with no effect on GPO or catalase. Tumor cells whose GR was inactivated by BCNU could be lysed by fluxes of H(2)0(2) to which they were otherwise completely resistant. They could be killed by phorbol myristate acetate (PMA)-stimulated, bacilli Calmette-Guerin-activated macrophages in numbers which were otherwise insufficient, and by nonactivated macrophages, which otherwise were ineffective. BCNU-treated target cells were also much more sensitive to antibody-dependent, macrophage-mediated cytolysis. However, such tumor cells were no more sensitive than controls to lysis by alloreactive T cells or by antibody plus complement. Next, we deprived tumor cells of selenium by passage in selenium-deficient mice. GPO was inhibited 85 percent in such cells, with no effect on GR or catalase. Tumor cells with reduced GPO activity were markedly sensitized to lysis by small fluxes of H(2)0(2) or by PMA-stimulated macrophages or granulocytes. In contrast, inhibition of catalase with aminotriazole had no effect on the sensitivity of three tumors to peroxide-mediated lysis, and had modest effects with two others. Thus, the oxidation-reduction cycle of glutathione serves as one of the major defense mechanisms of tumor cells against three related forms of oxidant injury: lysis by fluxes of H(2)0(2), by PMA-triggered macrophages, and by macrophages in the presence of anti-tumor antibody.     

Antitumor effects of hydrogen peroxide in vivo

Glucose oxidase, covalently coupled to polystyrene microspheres (GOL), produced H(2)0(2) at an average rate of 3.6 nmol/min per 10(9) beads under standard assay conditions. Injection of 1.3 × 10(10) to 1.1 × 10(11) GOL i.p. prolonged the survival of mice by 27 percent after injection of 10(6) P388 lymphoma cells in the same site, consistent with destruction of 97.6 percent of the tumor cells. Placing mice for several hours in 100 percent O(2), the probable rate-limiting substrate for GOL, afforded a 42 percent prolongation of survival from P388 lymphoma, consistent with destruction of 99.6 percent of the tumor cells. When the P388 inoculum was 10(5), 10(4), or 10(3) cells, GOL led to long-term survival (presumed cure) of 23 percent, 77 percent, and 92 percent of the mice, respectively, consistent with reduction of the injected tumor dose to less than 10 cells. Subcutaneous growth of 10(5) P388 cells (approximately 300 lethal dose to 50 percent of mice) was suppressed in 83 percent of mice by admixture of GOL with the tumor cell inoculum. GOL alone had no effect against a more peroxide-resistant tumor, P815 mastocytoma. However, P815 cell glutathione reductase could be inhibited in vivo by well-tolerated doses of the antitumor agent, 1,3-bis(2-chloroethyl)- 1-nitrosourea (BCNU). BCNU alone cured few mice with P815. Together, BCNU and GOL apparently cured 86 percent of mice injected with 10(6) P815 cells i.p. The protective effect of GOL was abolished by boiling it to inactivate the enzyme, by co-injection of catalase coupled to latex beads, or by delaying the injection of tumor cells for 3 h, by which time the beads had formed aggregates. Soluble glucose oxidase, in doses threefold higher than that bound to GOL, had no detectable antitumor effect. A single injection of preformed H(2)0(2) readily killed P388 cells in the peritoneal cavity, but only at doses nearly lethal to the mice. In contrast, GOL had very little toxicity, as judged by the normal appearance of the mice for over 400 d, gross and microscopic findings at autopsy, and various blood tests. GOL injected i.p. remained in the peritoneal cavity, where it was gradually organized into granulomata by macrophages, without generalized inflammation. Thus, an H(2)0(2)-generating system confined to the tumor bed exerted clear- cut antitumor effects with little toxicity to the host.     

14C-urea breath test in patients undergoing anti-tuberculosis therapy

AIM: Urea breath test (UBT) is a non-invasive diagnostic test for detecting the presence of Helicobacterpylori(H pylori). In this study we evaluated the effect of anti-tuberculosis therapy on the results of 14C-UBT. METHODS: Patients, with the diagnosis of tuberculosis (TB) who had a positive UBT at the point of starting anti-TB therapy, were included. None had a history of peptic ulcer disease or had taken antibiotics, bismuth compounds and/or PPI in the previous month. 14C-UBT was repeated at the end of the second month and the end of treatment period and one month after completion of treatment course. RESULTS: Thirty-five patients (23 males) were enrolled. 14C-UBT was negative in all 35 patients (100%) at the end of the second month and remained negative in 30 cases (85.7%) at the end of the treatment course. One month after completion of treatment course, UBT remained negative in 13 patients (37.1%). CONCLUSION: Our report underscores the need for caution while interpreting urea breath test results in patients undergoing anti-TB therapy. Furthermore, the combination of drugs used in this study resulted in H pylori eradication in a minority of patients.     

Triple, standard quadruple and ampicillin-sulbactam-based quadruple therapies for H pylori eradication： A comparative three-armed randomized clinical trial

AIM: To compare the effectiveness of triple, standard quadruple and ampicillin-sulbactam-based quadruple therapies for H pylori eradication in a comparative threearmed randomized clinical trial. METHODS: A total of 360 H pylori-positive patients suffering from dyspepsia and aging 24-79 years with a median age of 42 years were enrolled in the study and randomly allocated into the following three groups: group A (n = 120) received a standard 1-wk triple therapy (20 mg omeprazole b.i.d., 1000 mg amoxicillin b.i.d., 500 mg clarithromycin b.i.d.); group B (n = 120) received a 10-d standard quadruple therapy (20 mg omeprazole b.i.d., 1000 mg amoxicillin b.i.d., 240 mg colloidal bismuth subcitrate b.i.d., and 500 mg metronidazole b.i.d.); group C (n = 120) received the new protocol, i.e. 375 mg sultamicillin (225 mg ampicillin plus 150 mg sulbactam) b.i.d. (before breakfast and dinner), instead of amoxicillin in the standard quadruple therapy for the same duration. Chi-square test with the consideration of P < 0.05 as significant was used to compare the eradication rates by intention-to-treat and per-protocol analyses in the three groups. RESULTS: The per-protocol eradication rate was 91.81% (101 patients from a total of 110) in group A, 85.84% (97 patients from a total of 113) in group B, and 92.85% (104 patients from a total of 112) in group C. The intentionto-treat eradication rate was 84.17% in group A, 80.83% in group B, and 86.67% in group C. The new protocol yielded the highest eradication rates by both per-protocol and intention-to-treat analyses followed by the standard triple and quadruple regimens, respectively. However, the differences were not statistically significant between the three groups. CONCLUSION: The results of this study provide further support for the equivalence of triple and quadruple therapies in terms of effectiveness, compliance and side-effect profile when administered as first-line treatment for H pylori infection. Moreover, the new protocol using ampicillin-sulbactam instead of amoxicillin in the quadruple regimen is a suitable first-line alternative to be used in regions with amoxicillin-resistant H pylori strains.     

二十五味珊瑚丸中酯型生物碱和硫化汞的含量测定

目的:首次建立藏药复方二十五味珊瑚丸中酯型生物碱和硫化汞含量测定方法。方法:采用HPLC测定二十五味珊瑚丸中酯型生物碱。硫氰酸盐法测定硫化汞。Phenomenex Luna C18(2)色谱柱(4.6 mm×150 mm,5μm);柱温:35℃;流动相:甲醇-0.05 mol.L-1磷酸二氢钾-醋酸-异丙醇(67∶173∶4∶4);检测波长:230 nm;流速:1.0 mL.min-1。结果:乌头碱线性方程为Y=6.974×105X-28.1,r=0.999 8;表明乌头碱在0.096~0.480μg范围内进样量与峰面积呈良好线性关系。平均回收率为93.1%,RSD为2.1%。结论:该法准确、可靠、重复性好,可有效控制二十五味珊瑚丸中酯型生物碱和硫化汞限量。     

临床路径的经济学特征及其对临床护理的启示

临床路径以满足医院、患者及保险机构的需求为出发点,经济有效性是其本质特征.本文从临床路径的经济学特征出发,详细解析临床护理路径发展所面临的现实挑战,并对其未来发展进行展望.     

Resting macrophages produce distinct metabolites from exogenous arachidonic acid

Resident mouse peritoneal macrophages rapidly metabolize free arachidonic acid (20:4) in the absence of a discernible trigger. After a 20-min incubation in serumless medium, one-third of the fatty acid was found esterified in cell phospholipid and two-thirds was metabolized to oxygenated products which were recovered in the culture medium. The 20:4 oxygenated metabolites were identified by reverse-phase high performance liquid chromatography as hydroxyeicosatetraenoic acids (HETEs) and 6-keto prostaglandin F(1a) (6-ketoPGF(1a)), the stable form of prostacyclin, together with prostaglandin E(2) (PGE(2)) in proportions of 67:24:9. Inhibitor studies using indomethacin, nordihydroguaiaretic acid, and 5,8,11,14-eicosatetraenoic acid confirmed these metabolites to be lipoxygenase and cyclo-oxygenase products. The proportion of products differs considerably from those generated from phospholipid 20:4 in response to a phagocytic stimulus (HETEs:6-ketoPGF(1a):PGE(2):leukotriene C, 15:25:40: 15-20). Cornyebacterium parvum-elicited macrophages incorporated a higher percentage (70 percent) of exogenously supplied 20:4 and converted less than 20 percent of the fatty acid to oxygenated metabolites. Cyclo-oxygenase products (PGE(2), PGF(2a), TXB(2), and 6-ketoPGF(1a)) represented the major 20:4 metabolites (74 percent) synthesized by these activated macrophages. Esterification of 20:4 into cell phospholipids appeared not to be an initial obligatory step for synthesis of 20:4 oxygenated products by this route. To the contrary, incorporation of 20:4 into cell lipids and metabolism via the cyclo-oxygenase and lipoxygenase pathways represent distinct metabolic fates of exogenously supplied 20:4. These observations establish that resting macrophages contain high levels of cyclo-oxygenase and lipoxygenase activity and suggest macrophages can synthesize lipid mediators of inflammation in the absence of an inflammatory stimulus.     

Concomitant bacteraemia as a risk factor for diarrhoeal disease mortality in Karachi: a case-control study of hospitalized children

The objective of this study was to evaluate risk factors for death due to diarrhoea among hospitalized children at the Aga Khan University Hospital (AKUH), Karachi. We conducted a retrospective case-control study of all diarrhoea deaths at AKUH over the period 1988–93. For each death, the next two consecutive admissions matched for gender and type of diarrhoea were identified as controls. Data were analysed by univariate methods and logistic regression analysis. A total of 42 deaths and 84 matched controls were identified. Blood cultures at admission were obtained in all deaths and 94% of controls. The rates of isolation of organisms from blood cultures were significantly higher among deaths [38 versus 9%, odds ratio (OR) 6.5, 95% confidence interval (CI) 2.2–19.9], the majority of which were Gram-negative Enterobacteriaceae (94 versus 57%, Fisher's exact test p < 0.02). Conditional logistic regression revealed that several clinical and laboratory features of systemic infection were associated with a significantly increased risk of mortality, such as anorexia (OR 3.9,95% CI 1.4 10.9), drowsiness (OR 4.4,95% CI 1.3–15.3), respiratory distress (OR 7.0,95% CI 1.4 36.6), anaemia (OR 5.8, 95% CI 2.0–16.6) and a positive blood culture (OR 8.7, 95% CI 2.5–30.7). Our data suggest that bacteraemia with Enterobacteriaceae is common among hospitalized malnourished children with diarrhoea and systemic infection may be an important risk factor for mortality.