***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Abstract Gram-negative bacteria account for up to 35 % of postoperative sternal wound infections ( SWI ) in patients undergoing cardiac surgery . Despite this , risk factors for Gram-negative SWI have not been investigated . The objective of this study was to define risk factors associated with Gram-negative SWI in patients undergoing cardiac surgery . 2590 patients undergoing cardiac surgery between 2002 - 2005 were prospect ively monitored for development of SWI . Patient , operative , and post-operative risk factors were compared among patients that developed Gram-negative SWI and Gram-positive SWI to uninfected controls using univariate and multivariate analysis . A p<0.05 was considered significant . Surgical site infections developed in 152 ( 5.9 % ) patients . Isolates were recovered from the sternum for 128 ( 5.0 % ) patients , from the leg donor site for 19 ( 0.73 % ) patients , and from the sternum and donor site for 5 ( 0.19 % ) patients . Gram-positive pathogens were isolated from 83 ( 3.3 % ) patients , Gram-negative pathogens from 42 ( 1.6 % ) patients , and mixed pathogens from 27 ( 1.0 % ) patients . Hospital admission greater than 48 hours before surgery ( OR : 2.25 ; 95 % CI : 1.11- 4.58 ) , ventilator-dependency preoperatively ( OR : 5.32 95 % CI : 2.22 - 12.75 ) , and thoracentesis procedure postoperatively ( OR : 3.71 ; 95 % CI : 1.45 - 9.49 ) and diabetes ( OR : 2.04 ; 95 % CI : 1.17 - 3.55 ) were identified as significant risk factors for SWI due to Gram-negative bacteria using multivariate logistic regression . Diabetes , increased age , and peripheral vascular disease were identified as significant risk factors for SWI due to Gram-positive bacteria ( p<0.05 , each ) . The risk factors associated with Gram-negative SWI differed significantly from those associated with Gram-positive SWI . Risk factors associated with Gram-negative SWI were identified . Unique interventions may be necessary to prevent Gram-negative SWI in cardiac surgery The outcome of coronary artery bypass grafting ( CABG )  in diabetic patients has traditionally been worse than in non-diabetic patients . Recent studies have suggested an improvement in outcome in diabetic patients undergoing contemporary CABG .  However , the direct impact of diabetes on mortality and morbidities following CABG remains unclear . We retrospectively analyzed prospect ively collected data of 2725 CABG patients from January 1998 to December 2005 : one thous and and eighty-five ( 40 % ) diabetics and 1640 ( 60 % ) non-diabetics [ mean age 65+/-11 years , 1882 ( 69 % ) male ] . Subgroup analysis was performed for two study periods ( 1998 - 2002 vs. 2003 - 2005 ) . The overall hospital mortality was 1.8 % [ n=50 ; diabetics : 2.4 % , non-diabetics : 1.5 % ( P=0.07 ) ] . The mortality rate among diabetics decreased from 3.1 % in 1998 - 2002 to 1.0 % in 2003 - 2005 ( P=0.021 ) . Diabetes was not an independent predictor of hospital mortality but predicted the occurrence of deep sternal wound infection ( OR=3.77 ) . Diabetes significantly decreased long-term survival [ 1-year and 5-year survival 94.7+/-0.7 % and 81.9+/-1.4 % for diabetic vs. 95.4+/-0.5 % and 85.9+/-1.0 % for non-diabetic patients ( P=0.01 ) ] . Excellent results following contemporary CABG can be expected in diabetics with a similar mortality compared to non-diabetics . Therefore , our data suggest that diabetes may , in fact , not be a risk factor for adverse outcome following CABG . However , long-term survival in diabetics remains significantly inferior compared to non-diabetics In a 60-week cross-over study on 5536 patients in 20 wards of three city hospitals ( two general and one orthopaedic ) , pre-operative bathing with chlorhexidine-detergent  failed to influence the incidence of postoperative infection , in spite of the relatively high incidence of infection with skin organisms . Of the patients bathing pre-operatively with chlorhexidine-detergent , 5.4 per cent subsequently became infected ( 4.0 per cent of clean wounds ) and of those bathing with unmedicated soap 4.9 per cent ( 3.5 per cent of clean wounds ) . A single pre-operative bath with chlorhexidine-detergent would , therefore , appear to be of dubious value in preventing postoperative wound infection Background To report our experience , with  Deep mediastinal wound infections ( DMWI ) .  Emphasis was given to the management of deep infections with omental flaps Methods From February 2000 to October 2007 , out of 3896 cardiac surgery patients ( prospect i ve data collection ) 120 pts ( 3.02 % ) developed sternal wound infections . There were 104 males & 16 females ; ( 73.7 % ) CABG , ( 13.5 % ) Valves & ( 9.32 % ) CABG and Valve . Results Superficial sternal wound infection detected in 68 patients ( 1.75 % ) and fifty-two patients ( 1.34 % ) developed DMWI . The incremental risk factors for development of DMWI were : Diabetes ( OR = 3.62 , CI = 1.2 - 10.98 ) , Pre Op Creatinine > 200 μmol/l ( OR = 3.33 , CI = 1.14 - 9.7 ) and Prolong ventilation ( OR = 4.16 , CI = 1.73 - 9.98 ) . Overall mortality for the DMWI was 9.3 % and the specific mortality of the omental flap group was 8.3 % . 19 % of the " DMWI group " , developed complications : hematoma 6 % , partial flap loss 3.0 % , wound dehiscence 5.3 % . Mean Hospital Stay : 59 ± 21.5 days . Conclusion Post cardiac surgery sternal wound complications remain challenging . The role of multidisciplinary approach is fundamental , as is the importance of an aggressive early wound exploration especially for deep sternal infections Several risk factors for deep sternal wound infection  after sternotomy  remain unclear . To assess and compare risk factors among units , a prospect i ve study included 1830 patients in 10 units during a 4-month period : 960 underwent coronary artery bypass grafting and 870 underwent other procedures .  According to the Centers for Disease Control and Prevention definitions , 2.3 % of patients ( 42/1830 ) acquired a deep sternal wound infection . Independent risk factors for deep sternal wound infection were obesity , coronary artery bypass grafting , reoperation , and postoperative inotropic support . Independent risk factors after coronary artery bypass grafting were obesity , bilateral internal thoracic artery grafting , reoperation , and postoperative inotropic support . In all five of the units usually performing bilateral internal thoracic artery graftings , this procedure was associated with high risk of deep sternal wound infection . Duration of operation was a major risk factor in comparison of the unit with the highest risk of deep sternal wound infection with the other nine units ; this suggests that parameters related to the perioperative period were involved . Multicenter surveillance is useful to determine reliable risk factors for deep sternal wound infection , to define a high-risk population before operation , and to assess unit-specific risk factors OBJECTIVE To identify risk factors associated with surgical-site infection according to the depth of infection , the cardiac procedure , and the National Nosocomial Infections Surveillance System risk index . DESIGN Prospect i ve survey conducted during a 12-month period . SETTING A 48-bed cardiac surgical department in a teaching hospital . PATIENTS Patients admitted for cardiac surgery between February 2002 and January 2003 . RESULTS Surgical-site infections were diagnosed in 3 % of the patients ( 38 of 1,268 ) . Of the 38 surgical-site infections , 20 were superficial incisional infections and 18 were mediastinitis for incidence rates of 1.6 % and 1.4 % , respectively . Cultures were positive in 28 cases and the most commonly isolated pathogen was Staphylococcus . A National Nosocomial Infections Surveillance System risk index score of 2 or greater was associated with a risk of surgical-site infection ( relative risk , 2.4 ; P < .004 ) . Heart transplantation , mechanical circulatory assistance , coronary artery bypass graft with the use of internal mammary artery , and reoperation for cardiac tamponade or pericard effusion were independent risk factors associated with surgical-site infection . CONCLUSIONS Data surveillance using incidence rates stratified by cardiac procedure and type of infection is relevant to improving infection control efforts . Risk factors in patients who developed superficial infection were different from those in patients who developed mediastinitis . Coronary artery bypass graft using internal mammary artery was associated with a high risk of surgical-site infection , and independent factors such as reoperation for cardiac tamponade or pericard effusion increased the risk of infection Objective . To evaluate if glycosylated haemoglobin 1 ( HbA1c ) was associated with increased risk of infection and mortality  after coronary artery bypass grafting ( CABG ) .  Design . Prospect i ve observational study . Preoperative HbA1c concentrations were correlated to outcome in patients followed for an average of 3.5 years after CABG . Results . HbA1c was ≥6 % in 68 % of 161 patients with diabetes mellitus ( DM ) and in 3 % of 444 patients without DM . Superficial sternal wound infection was observed in 13.9 % if HbA1c ≥6 % versus in 5.5 % if < 6 % ( p=0.007 ) . Mediastinitis occurred in 4.9 % if HbA1c≥6 % and in 2.1 % if HbA1c<6 % ( p=0.20 ) ( Hazard ratio ( HR ) 1.9 , 95 % CI 0.6 - 5.9 ) . Follow-up mortality was 18.9 % in patients with HbA1c≥6 % compared to 4.1 % if HbA1c<6 % ( p<0.001 ) with HR 5.4 , ( 95 % CI 3.0 - 10.0 ) after multivariable adjustment . The risk of death was similar regardless of DM diagnosis . Conclusions . HbA1c ≥6 % was associated with an increased risk of postoperative superficial sternal wound infections and a trend for higher mediastinitis rate and significantly higher mortality three years after CABG Background Sternal wound infection ( SWI ) is an uncommon but potentially life-threatening complication of cardiac surgery . Predisposing factors for SWI are multiple with varied frequencies in different studies . The purpose of this study was to assess the incidence , risk factors , and mortality of SWI after  coronary artery bypass grafting ( CABG ) at Tehran Heart Center . Methods This study prospect ively evaluated multiple risk factors for SWI  in 9201 patients who underwent CABG at Tehran Heart Center between January 2002 and February 2006 . Cases of SWI were confirmed based on the criteria of the Centers for Disease Control and Prevention . Deep SWI ( bone and mediastinitis ) was categorized according to the Oakley classification . Results In the study period , 9201 CABGs were performed with a total SWI rate of 0.47 percent ( 44 cases ) and deep SWI of 0.22 percent ( 21 cases ) . Perioperative ( in-hospital ) mortality was 9.1 % for total SWI and about 14 % for deep SWI versus 1.1 % for non-SWI CABG patients . Female gender , preoperative hypertension , high functional class , diabetes mellitus , obesity , prolonged intubation time ( more than 48 h ) , and re-exploration for bleeding were significant risk factors for developing SWI ( p = 0.05 ) in univariate analysis . In multivariate analysis , hypertension ( OR = 10.7 ) , re-exploration ( OR = 13.4 ) , and female gender ( OR = 2.7 ) were identified as significant predictors of SWI ( p < 0.05 for all ) . The rate of SWI was relatively similar in 3 groups of prophylactic antibiotic regimen ( Cefazolin , Cefazolin + Gentamycin and Cefazolin + Amikacin : 0.5 % , 0.5 % , and 0.34 % respectively ) . Conclusion Rarely reported previously , the two risk factors of hypertension and the female gender were significant risk factors in our study . Conversely , some other risk factors such as cigarette smoking and age mentioned as significant in other reports were not significant in 
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Conclusion Evidence from this study suggests the importance of latitude of study place and advanced age as risk factors of mediastinitis .
Latitude is a marker of thermally regulated bacterial virulence and other local surgical practice .
There is concern of increasing risk of mediastinitis and of MRSA in elderly patients undergoing sternotomy