Effect of antimicrobial prophylaxis on the incidence of infections in clean surgical wounds in hospitals undergoing renovation.

OBJECTIVE: To measure the effect of cephazolin prophylaxis on the rate of surgical site infection among patients with clean surgical wounds, categorized by risk group, in a hospital undergoing renovation. DESIGN: Randomized, double-blind clinical trial. SETTING: Saint Paul General Hospital, Coquimbo, Chile, during a period when it was undergoing significant interior remodeling. PATIENTS: General surgery patients who received antibiotic prophylaxis before clean wound surgery between March 2003 and May 2004 and a matched control group of patients who did not receive such prophylaxis. RESULTS: A total of 303 patients participated in the study. The rate of infection among patients with an American Society of Anesthesiologists (ASA) classification of 1 in the prophylaxis group was 7.3%, whereas among ASA 1 patients in a no-prophylaxis control group it was 10.3% (P=.40). In the prophylaxis group, the ASA 2 and ASA 3 patients combined had an infection rate of 10.5%, whereas in the no-prophylaxis group these patients had a rate of 30.0% (relative risk, 0.33 [95% confidence interval, 0.58-0.96]; P=.03). Both the ASA 2 and ASA 3 patients were protected from infection by prophylaxis; these patients had 1.7 and 2.2 times, respectively, more risk of developing a surgical site infection than did ASA 1 patients after a clean surgical procedure, but the ASA 2 and ASA 3 patients who did not receive prophylaxis had 4.3 and 4.8 times, respectively, greater risk of infection (relative risk, 0.91 [95% confidence interval, 0.83-0.99]; P=.02). Prophylaxis significantly reduced the rate of infection in the ASA 2 and ASA 3 groups. CONCLUSIONS: We recommend the use of antimicrobial prophylaxis with cephalosporins in ASA 2 and ASA 3 patients undergoing clean wound surgery during a period when significant renovations are being performed in the hospital.     

The national prevalence survey of nosocomial infections in Belgium, 1984

A national one-day prevalence survey of nosocomial infections was carried out in March 1984 in 106 Belgian acute-care hospitals involving 8723 patients of whom 6130 had undergone surgery. Three infections were studied: surgical wound infection, bacteraemia and urinary-tract infection. One or more of these three infections was recorded in 9.3% of all patients and in 11.8% of surgical patients. Prevalences increased with increasing duration of hospital stay and with higher ages, but the association of HAI with age was no longer significant after correction for duration of hospital stay. Prevalences varied considerably in different specialties. After adjustment for age and duration of stay, there was no association between perioperative antibiotic prophylaxis and the prevalence of the infections studied, but bias due to selection of higher risk patients in the antibiotic group was probable. Larger hospitals had a higher overall prevalence, but populations differed according to the size of the hospital. Bacteraemia was strongly associated with the presence of an intravenous catheter, and urinary-tract infection with a urinary catheter.     

Nosocomial infections and misuse of antibiotics in a provincial community hospital, Saudi Arabia

The incidence of nosocomial infection and prevalence of antibiotic misuse were studied in a 174-bed community hospital in Saudi Arabia over a six-month period. Of 2445 patients admitted, 8.5% developed nosocomial infection, the rates were highest for nursery (35.8%), intensive care (19.8%), gynaecological (16.2%) and surgical (11.7%) patients. Urinary tract (31.3%), wound (27.1%) and blood (14.9%) infections accounted for more than 70% of the infections. Staphylococcus aureus (23%) and Pseudomonas aeruginosa (11%), caused more than 90% of the infections. The majority of the bacterial pathogens (79%) were multi-drug resistant. Over 80% of patients were administered prophylactic and/or therapeutic antibiotics, with 53% receiving multiple antibiotics; 72% of the antibiotics were judged to be misused. Both prophylaxis and treatment were mostly misguided and clinically unwarranted. Host- and hospital-associated infection risk factors were identified. The minimum government cost estimates for the nosocomial infections and misused antibiotics were US $273 180 and $565 603, respectively. The findings emphasize the need for effective measures to reduce both the high infection rates and widespread antibiotic misusage in the hospital. Such measures should include institution of an effective infection control committee and a hospital antibiotic policy.     

An observer blind trial of co-amoxiclav versus cefuroxime plus metronidazole in the prevention of postoperative wound infection after general surgery

A consecutive series of 509 patients undergoing abdominal surgery were entered into a randomized, observer and patient blind, controlled, prospective, study to evaluate the efficiency of co-amoxiclav (‘Augmentin’, SmithKline Beecham, UK) compared with cefuroxime (‘Zinacef’ Glaxo, UK) plus metronidazole (Flagyl, M&B, UK) for the prevention of postoperative wound infections. One or three doses of antibiotics were given depending on the type of surgery and operative factors. Co-amoxiclav was given to 230 patients with a total wound infection rate of 5·6% and cefuroxime plus metronidazole were given to 225 patients with a total wound infection rate of 3%. The difference between infection rates was not significant. Both groups were comparable in terms of demographic details, type and duration of surgery, risk factors associated with surgical procedures and postoperative management. Although not statistically significant, a difference in the wound infection rate for those patients undergoing colorectal surgery was seen: for the co-amoxiclav group and for the cefuroxime/ metronidazole group. The estimated cost to our hospital (October 1993) of one dose of co-amoxiclav was less that half the cost of cefuroxime and metronidazole. This study demonstrates that co-amoxiclav is an effective prophylactic antibiotic for abdominal surgery.     

Short antibiotic prophylaxis for bacterial infections in a neonatal intensive care unit: a randomized controlled trial

We compared the effectiveness of a single dose and a three-day course of antibiotic prophylaxis in preventing bacterial infections in high-risk neonates. The study was a prospective, randomized controlled trial conducted in a 20-bed tertiary referral neonatal intensive care unit (NICU). A series of 130 neonates admitted consecutively to the NICU, fulfilling risk factors for infection, were assigned at random to receive intravenous antibiotic prophylaxis with ampicillin and netilmicin either in two daily doses for 72 h (three-day-administration group, 67 infants) or in a single bolus injection on admission (bolus group, 63 infants). Hospital-acquired infection, the main outcome measure, was defined as infection that developed at least 48 h after admission, and vertical infection (maternally transmitted) was considered to be present when clinical symptoms and abnormal laboratory findings became evident within 48 h of birth. Infections were considered as suspected when clinical and laboratory findings of infection were present, without positive cultures, and as confirmed when positive cultures were also present. No significant differences were found between the two groups of neonates studied in mean birth weight, gestational age or postnatal age on admission. The incidence of vertical infection was similar in the two groups (16/67, 23.9% vs. 14/63, 22.2%). Of the 130 newborns studied, 29 (22.3%) acquired at least one nosocomial infection during their NICU stay; total hospital-acquired infections, calculated as the incidence density of infection (the number of infective episodes divided by the number of days in the NICU), were less frequent among newborns who received the three-day course than the bolus (relative risk 0.69). This difference, although not statistically significant, depended on the different incidence density of confirmed nosocomial infections rather than on suspected infections (relative risk 0.59; 95% confidence interval 0.32-1.09; P=0.1). There were no significant differences between the two groups in overall mortality. A single bolus administration on admission is therefore likely to be as effective as a three-day course of antibiotic prophylaxis in preventing bacterial infection in high-risk infants admitted to an NICU.     

Integrated Monitoring of a New Group B Streptococcal Disease Prevention Program and Other Perinatal Infections

Objective: To determine levels of prenatal screening for several infections, intrapartum recognition of risk factors, and prophylaxis against mother-to-child transmission of group B streptococcus. Methods: Review of stratified random sample of hospital records for deliveries in Connecticut during 1996. SUDAAN analysis was used to adjust for the complex survey design, and weighting adjusted for the probability of being sampled and nonresponse. Results: Of 992 records requested, 868 (88%) were abstracted and analyzed. Thirty-six percent of women had prenatal screening for group B streptococcus and 26% had been tested for human immunodeficiency virus (HIV), while 97–99% of women had been screened prenatally for hepatitis B surface antigen, rubella, and syphilis. Of those women tested, 17% were detected as group B streptococcus carriers, and 78% of these received intrapartum antibiotic prophylaxis. Among women who were not screened for group B streptococcus prenatally, 22% met risk-based criteria for prophylaxis, but only 45% of these received intrapartum prophylaxis. Among unscreened women with a risk factor, those with shorter hospital stays prior to delivery, admitted on evening or night shifts, or who delivered on the weekend were significantly less likely to receive intrapartum prophylaxis. Conclusion: In 1996, the majority of women who delivered in Connecticut were not tested prenatally for group B streptococcus and the majority of those not tested in whom there was an indication for prophylaxis were not treated. Compliance with group B streptococcus prevention recommendations can be improved through increased prenatal testing and/or better recognition of risk-based criteria for intrapartum prophylaxis.     

Prospective surveillance for surgical site infection in St. Petersburg, Russian Federation.

OBJECTIVE: To assess the risk-adjusted incidence and predictors of surgical site infections (SSIs). DESIGN: Prospective, multicenter, observational cohort study. SETTING: Seven surgical departments at 3 urban academic hospitals in St. Petersburg, Russian Federation. PATIENTS: All patients had surgery performed between January 15 and May 12, 2000. A total of 1,453 surgical procedures were followed up. Medical records were unavailable for less than 3% of all patients; patients were not excluded for any other reason. The mean patient age was 49.3 years, 61% were female, and 34% had an American Society of Anesthesiologists physical status classification (hereafter, "ASA classification") of at least 3. Surgery for 45% of the patients was emergent. RESULTS: In all, 138 patients (9.5%) developed SSI, for a rate that was approximately 3.5 times the risk-stratified rates in the United States. Male sex (odds ratio [OR], 1.54), ASA classifications of 3 (OR, 3.7) or 4 (OR, 5.0), longer duration of surgery (OR, 2.2), and wound classes of 3 (OR, 5.5) or 4 (OR, 14.3) were associated with increased SSI risk in multivariate analysis. Endoscopic surgery was associated with a lower risk of SSI (OR, 0.23). Antibiotic prophylaxis was used in 0%-33% of operations, and 69% of uninfected patients received antibiotics after the operation. CONCLUSIONS: The SSI rates are significantly higher than previously reported. Although this finding may be attributable to inadequate antibiotic prophylaxis, local infection control and surgical practices may also be contributors. Use of antibiotic prophylaxis should be encouraged and the effect of local practices further investigated. Active SSI surveillance should be expanded to other parts of the Russian Federation.     

Prevention of infection after induced abortion: release date October 2010: SFP guideline 20102

One known complication of induced abortion is upper genital tract infection, which is relatively uncommon in the current era of safe, legal abortion. Currently, rates of upper genital tract infection in the setting of legal induced abortion in the United States are generally less than 1%. Randomized controlled trials support the use of prophylactic antibiotics for surgical abortion in the first trimester. For medical abortion, treatment-dose antibiotics may lower the risk of serious infection. However, the number-needed-to-treat is high. Consequently, the balance of risk and benefits warrants further investigation. Perioperative oral doxycycline given up to 12 h before a surgical abortion appears to effectively reduce infectious risk. Antibiotics that are continued after the procedure for extended durations meet the definition for a treatment regimen rather than a prophylactic regimen. Prophylactic efficacy of antibiotics begun after abortion has not been demonstrated in controlled trials. Thus, the current evidence supports pre-procedure but not post-procedure antibiotics for the purpose of prophylaxis. No controlled studies have examined the efficacy of antibiotic prophylaxis for induced surgical abortion beyond 15 weeks of gestation. The risk of infection is not altered when an intrauterine device is inserted immediately post-procedure. The presence of Chlamydia trachomatis, Neisseria gonorrhoeae or acute cervicitis carries a significant risk of upper genital tract infection; this risk is significantly reduced with antibiotic prophylaxis. Women with bacterial vaginosis (BV) also have an elevated risk of post-procedural infection as compared with women without BV; however, additional prophylactic antibiotics for women with known BV has not been shown to reduce their risk further than with use of typical pre-procedure antibiotic prophylaxis. Accordingly, evidence to support pre-procedure screening for BV is lacking. Neither povidone-iodine nor chlorhexidine have been shown to alter the risk of infection when used as cervicovaginal preparation. However, chlorhexidine appears to be more effective than povidone iodine at reducing bacteria within the vagina. The Society of Family Planning recommends the routine use of antibiotic prophylaxis, preferably with doxycycline, before surgical abortion. Use of treatment doses of antibiotics with medical abortion may decrease the rare risk of serious infection but universal requirement for such treatment has not been established.     

医院等级评审对围手术期预防应用抗菌药物影响评价

目的为规范医院围手术期抗菌药物预防性应用、探索合理干预措施管理提供依据。方法通过医院感染监测系统,调取2（113年3月、5月医院外科手术病例728例作为非干预组：调取2013年10月、2014年1月全院外科手术病例742例作为干预组。通过各项指标分析比较干预前后围手术期预防性使用抗菌药物情况。结果开展围手术期抗菌药物临床应用专项整治活动后,I类切口手术抗菌药物使用率由100％降至31．66%,围手术期抗菌药物使用率由100％降至59．03％,且术后切口部位感染并未出现增长。术前0．5～2h用药率由整治前的81．59％升高至100％（P〈0．05）。专项整治后围手术期预防应用抗菌药物时长由5．72天降至1．56天。整治后围术期抗菌药物合理应用明显提高。结论医院开展围手术期抗菌药物预防应用专项整治取得明显成效。     

Role of antibiotic prophylaxis for wound infection in percutaneous endoscopic gastrostomy (PEG): result of a prospective double-blind randomized trial

A randomized, double-blind, controlled trial was carried out to determine the value of antibiotic prophylaxis in the prevention of wound infection in percutaneous endoscopic gastrostomy (PEG) procedures. The wound was evaluated using ASEPSIS method and categorized as disturbance of healing, minor or major wound infection on the 7th day and the 28th day. The rate of infection including major wound infection was lower in the prophylaxis group of patients at both seven and 28 days.     

医院感染的横断面调查与分析

目的 了解医院感染现患率、医院感染发生的特点及抗菌药物使用情况.方法 采取床旁调查与病历调查相结合的方法,对2009年11月10日0:00-24:00全部住院患者进行调查,将调查结果进行统计分析.结果 医院感染例次感染率为3.66％;感染部位依次为呼吸道20例、皮肤与软组织4例、泌尿道3例;抗菌药物使用率51.27％;其中一联用药占71.11％、二联用药占25.96％;年龄、侵入性操作、基础疾病等是医院感染高危因素;外科围手术期预防用药偏高,使用抗菌药物共32种.结论 现患率调查方法简单,结果可靠,可以基本反映医院感染情况,提示应加强抗菌药物的合理应用,减少预防用药,降低抗菌药物使用率.     

How many nosocomial infections are missed if identification is restricted to patients with either microbiology reports or antibiotic administration?

OBJECTIVE: To investigate how many nosocomial infections would be missed if surveillance activities were restricted to patients having either microbiology reports or antibiotic administration. DESIGN: Analysis of data from a large prevalence study on nosocomial infections (Nosocomial Infections in Germany-Surveillance and Prevention). SETTING: A total of 14,966 patients were investigated in medical, surgical, obstetric-gynecologic, and intensive-care units of 72 German hospitals representatively selected according to size. Five hundred eighteen patients (3.5%) had at least one nosocomial infection. Microbiology reports were available for 56.6% of these patients on the prevalence day, and 86.3% received antibiotics. RESULTS: Only 31 nosocomially infected patients (6%) would have been missed by using either microbiology reports or antibiotic treatment as an indicator. These indicators of nosocomial infections had a high diagnostic sensitivity for nosocomial pneumonia (98.8%), urinary tract infections (96.3%), and primary bloodstream infections (95.3%), but a lower sensitivity for wound infections (85.4%). Thus, 97.4% of all nosocomial infections were found with this method in intensive-care units and 96.1% in medicine units, but only 89.7% in surgical departments. In 9 (12.5%) of 72 hospitals, the overall sensitivity would have been <80% using a combination of the two indicators. For this reason, the situation in one's own hospital should be checked before using this method. CONCLUSIONS: After checking the situation in one's own hospital, the "either-or" approach using the two indicators "microbiology report" and "antibiotic administration" can be recommended as a time-saving measure to diagnose pneumonia, urinary tract, and primary bloodstream infections. For wound infections, additional information obtained by changing dressings or participating in ward rounds is necessary to achieve satisfactory sensitivity in the surveillance of nosocomial infections. Of course, it is necessary that the surveillance staff discard all false positives to ensure a satisfactory specificity.     

Cost-effectiveness of antibiotic prophylaxis in elective cesarean section

Background

The proportion of pregnant women delivered by cesarean section has increased steadily during the past three decades. The risk of infection is 10-fold augmented after elective cesarean section compared to vaginal delivery. Antibiotic prophylaxis may reduce endometritis by 62% and superficial wound infection by 38% after elective cesarean section. International guidelines recommend antibiotic prophylaxis in elective cesarean section, but this procedure is not routinely followed in Sweden. Studies of costs of antibiotic prophylaxis in cesarean section show conflicting results and are based on substantially different incidence of postoperative infections. No study of costs of antibiotic prophylaxis in elective cesarean section in a Swedish or Nordic context has been pursued. The aim of this study was to investigate if antibiotic prophylaxis is cost-reducing in elective cesarean section in Örebro County, Sweden.

Methods

All women undergoing elective cesarean in the Region Örebro County health care system during 2011–2012 were eligible for inclusion. Postoperative infections and risk factors for infections were registered. A hypothetical situation in which all participants had received antibiotic prophylaxis was compared to the actual situation, in which none of them had received antibiotic prophylaxis. The reduction in the risk of postoperative infections resulting from antibiotic prophylaxis was based on a meta-analysis. Costs for in-patient care of postoperative infections were extracted from the accounting system, and costs for out-patient care were calculated according to standard costs. Costs for antibiotic prophylaxis were calculated and compared with the cost reduction that would be implied by the introduction of such prophylaxis.

Results

The incidences of deep and superficial surgical site infection were 3.5% and 1.3% respectively. Introduction of antibiotic prophylaxis would reduce health care costs by 31 Euro per cesarean section performed (95% credible interval 4–58 Euro). The probability of cost-saving was 99%.

Conclusions

Antibiotic prophylaxis in elective cesarean section is cost-reducing in this health care setting. Our results indicate that the introduction of antibiotic prophylaxis in elective cesarean section can also be cost-saving in low infection rate settings.Trial registration Ethical approval was given by the Regional Ethical Review Board in Uppsala (registration number 2013/484).

     

A randomized prospective study to compare ceftizoxime with cephradine as single dose prophylaxis in elective cholecystectomy

This study compares the efficacy of ceftizoxime with that of cephradine as single agent prophylaxis in elective cholecystectomy. The incidence of purulent wound infection was low in both groups (ceftizoxime 1/99; cephradine 2/92). No adverse reactions to the trial antibiotics occurred in either group. Ceftizoxime is a safe, effective, convenient and well-tolerated antibiotic for use as single agent prophylaxis in elective cholecystectomy. However, because it has no demonstrable advantage over cephradine and is three times as expensive, its routine use is not justified.     

Impact of local guidelines and an integrated dispensing system on antibiotic prophylaxis quality in a surgical centre

Surgical antibiotic prophylaxis is effective in preventing postoperative wound infections. Guidelines are designed to optimize antimicrobial use in this setting. The aim of this study was to assess antibiotic use in surgical prophylaxis in a surgical hospital before and after the implementation of both local antibiotic prophylaxis guidelines and a specific medication set for various surgical procedures. The appropriateness of surgical antibiotic prophylaxis increased from 50.9% in the pre-implementation stage to 94.9% in the postimplementation stage (P<0.001). The implementation of a multidisciplinary protocol and design of medication sets helped to improve the practice of surgical antibiotic prophylaxis.     

普外科围手术期预防性使用抗菌药物调查分析

目的了解普外科围手术期预防性使用抗菌药物现状、评价其合理性;提出合理使用抗菌药物的方案,控制医院感染的发生. 方法对普外科围手术期预防性抗菌药物的使用进行目标性监测;在围手术期预防性使用抗菌药物的患者中,随机抽取290例患者进行围手术期预防性使用抗菌药物合理性评价. 结果普外科6 284例次住院患者中手术患者5 312例次,采用围手术期预防性使用抗菌药物3 126例次,围手术期抗菌药物使用率58.85%;发生医院感染 232例次,医院感染率3.69%;在调查的 290例病例中,53.5%的Ⅰ类切口患者、100%的Ⅱ类切口和Ⅲ类切口患者使用抗菌药物. 结论普外科不合理应用抗菌药物比较严重,要加强合理应用抗菌药物管理、加强制度化管理、加强合理应用抗菌药物知识教育,进一步提高合理应用抗菌药物知识水平.     

Effect of optimized antibiotic prophylaxis on the incidence of surgical site infection.

OBJECTIVE: To compare the rate of surgical site infection (SSI) before and after an intervention period in which an optimized policy for antibiotic prophylaxis was implemented. To demonstrate that a more prudent, restrictive policy would not have a detrimental effect on patient outcomes. DESIGN: Before-after trial with prospective SSI surveillance in the Dutch nosocomial surveillance network (Preventie Ziekenhuisinfecties door Surveillance [PREZIES]), using the criteria of the Centers for Disease Control, including postdischarge surveillance for up to 1 year. METHODS: During a preintervention period and a postintervention period (both 6-13 months), 12 Dutch hospitals collected data on antimicrobial prophylaxis and SSI rates. The study was limited to commonly performed surgical procedures in 4 specialties: vascular, intestinal, gynecological and orthopedic surgery. Selected risk factors for analysis were sex, age, American Society of Anesthesiologists classification, wound contamination class, duration of surgery, length of hospital stay before surgery, and urgency of surgery (elective or acute). RESULTS: A total of 3,621 procedures were included in the study, of which 1,668 were performed before the intervention and 1,953 after. The overall SSI rate decreased from 5.4% to 4.5% (P=.22). Among the procedures included in the study, the largest proportion (55%) were total hip arthroplasty, and the smallest proportion (2%) were replacement of the head of the femur. SSI rates varied from 0% for vaginal hysterectomy to 21.1% for femoropopliteal or femorotibial bypass surgery. Crude and adjusted odds ratios showed that there were no significant changes in procedure-specific SSI rates after the intervention (P>.1). CONCLUSIONS: An optimized and restrictive antibiotic prophylaxis policy had no detrimental effect on the outcome of clean and clean contaminated surgery, as measured by SSI rate.     

Prophylactic antibiotics to prevent surgical site infections in Botswana: findings and implications

Objectives: Antibiotic prophylaxis in surgery is known to reduce the rate of surgical site infections (SSI) as well as shorten hospital stay. However, there is currently a scarcity of data on antibiotic prophylaxis and SSIs among African countries including Botswana. Consequently, this study aimed to address this.

Methods: A prospective study involving 400 patients was carried out at a leading tertiary hospital in Botswana from 2014–2015. Patients’ demographic information, type of surgery performed and peri-operative use of antibiotics were documented. All enrolled patients were followed-up for 30 days post discharge to fully document the incidence of SSIs.

Results: Median age of patients was 35.5 (25 – 50) years, with 52% female. There were 35.8% emergency and 64.2% elective surgeries. The most common operations were exploratory laparotomy (25%), appendectomy (18.3%), excision, and mastectomy (8%). Antibiotics were given in 73.3% of patients, mainly postoperatively (58.3%). The most commonly prescribed antibiotics were cefotaxime (80.7%), metronidazole (63.5%), cefradine (13.6%) and amoxicillin/clavulanate (11.6%). The incidence of SSI was 9%. The most common organisms were Pseudomonas aeruginosa, Staphylococcus aureus, and coagulase-negative staphylococci.

Conclusion: The rate of SSI is a concern, and may be related to inappropriate antibiotic prophylaxis given post operatively. Interventions are in place to decrease SSI rates to acceptable levels in this leading hospital by improving for instance infection prevention practices including the timing of antibiotic prophylaxis. Research is also ongoing among other hospitals in Botswana to reduce SSI rates building on these findings.     

老年恶性肿瘤化疗患者医院感染及其相关因素分析

[目的 ]探讨老年恶性肿瘤化疗患者医院感染发生情况及其危险因素。 [方法 ]对 2 0 0 0～ 2 0 0 2年在广东医学院附院住院化疗的 42 3例老年恶性肿瘤患者的临床资料进行分析。 [结果 ]老年恶性肿瘤化疗患者医院感染率为 17 97% ,高于医院同期医院总感染率 ;呼吸系统肿瘤与晚期肿瘤患者较易发生医院感染 ;致病菌以革兰氏阴性条件致病菌为主 ;经Logistic分析 ,医院感染主要与住院时间 (OR =2 87)、应用抗生素 (OR =2 12 )、血白细胞计数减少 (OR =2 0 0 1)、侵入性医疗操作 (OR =3 2 5 )有关。 [结论 ]缩短住院时间 ,合理应用抗生素 ,避免过多侵入性医疗操作 ,是预防老年恶性肿瘤化疗患者发生医院感染的有效措施。