Antimicrobial prophylaxis in noninstrumented spine surgery: a prospective study to determine efficacy and drawbacks.

OBJECTIVE: The authors sought to evaluate the roles of perioperative antibiotic prophylaxis in noninstrumented spine surgery (NISS), both in postoperative infections and the impact on the selection of resistant bacteria. To the authors' knowledge, only one prospective study recommending preoperative intravenous (IV) antibiotics for prophylaxis has been published previously. METHODS: Two successive prospective IV antibiotic prophylaxis protocols were used: from 2011 to 2013 (group A: no prophylactic antibiotic) and from 2014 to 2016 (group B: prophylactic cefazolin). Patient infection rates, infection risk factors, and bacteriological status were determined. RESULTS: In total, 2250 patients (1031 in group A and 1219 in group B) were followed for at least 1 year. The authors identified 72 surgical site infections, 51 in group A (4.9%) and 21 in group B (1.7%) (p < 0.0001). A multiple logistic regression hazard model identified male sex (HR 2.028, 95% CI 1.173-3.509; p = 0.011), cervical laminectomy (HR 2.078, 95% CI 1.147-3.762; p = 0.016), and postoperative CSF leak (HR 43.782, 95% CI 10.9-189.9; p < 0.0001) as independent predictive risk factors of infection. In addition, preoperative antibiotic prophylaxis was the only independent favorable factor (HR 0.283, 95% CI 0.164-0.488; p < 0.0001) that significantly reduced infections for NISS. Of 97 bacterial infections, cefazolin-resistant bacteria were identified in 26 (26.8%), with significantly more in group B (40%) than in group A (20.9%) (p = 0.02). CONCLUSIONS: A single dose of preoperative cefazolin is effective and mandatory in preventing surgical site infections in NISS. Single-dose antibiotic prophylaxis has an immediate impact on cutaneous flora by increasing cefazolin-resistant bacteria.

Elderly age as a prognostic marker of 1-year poor outcome for subarachnoid hemorrhage patients through its interaction with admission hydrocephalus.

BACKGROUND: An increasing number of elderly patients are treated for aneurysmal subarachnoid hemorrhage. Given that elderly age is associated with both poor outcome and an increased risk of hydrocephalus, we sought to investigate the interaction between age and hydrocephalus in outcome prediction. METHODS: We enrolled 933 consecutive patients treated for subarachnoid hemorrhage between 2002 and 2010 and followed them for 1 yr after intensive care unit discharge. We first performed stepwise analyses to determine the relationship among neurologic events, elderly age (60 or more yr old), and 1-yr poor outcome (defined as Rankin 4-6). Within the most parsimonious model, we then tested for interaction between admission hydrocephalus and elderly age. Finally, we tested the association between age as a stratified variable and 1-yr poor outcome for each subgroup of patients with neurologic events. RESULTS: 24.1% (n=225) of subarachnoid hemorrhage patients were 60 yr old or more and 19.3% (n=180) had 1-yr poor outcomes. In the most parsimonious model (area under the receiver operating characteristic curve, 0.84; 95% CI: 0.82 to 0.88; P<0.001), elderly age and admission hydrocephalus were two independent predictors for 1-yr outcome (P<0.001 and P=0.004, respectively). Including the significant interaction between age and hydrocephalus (P=0.04) improved the model's outcome prediction (P=0.03), but elderly age was no longer a significant predictor. Finally, stratified age was associated with 1-yr poor outcome for hydrocephalus patients (P=0.007), but not for patients without hydrocephalus (P=0.87). CONCLUSION: In this observational study, elderly age and admission hydrocephalus predicted poor outcome, but elderly age without hydrocephalus did not. An external validation, however, will be needed to generalize this finding.

Morbidity of ventricular cerebrospinal fluid shunt surgery in adults: an 8-year study.

BACKGROUND: Cerebrospinal fluid (CSF) shunt procedures have dramatically reduced the morbidity and mortality rates associated with hydrocephalus. However, despite improvements in materials, devices, and surgical techniques, shunt failure and complications remain common and may require multiple surgical procedures. OBJECTIVE: To evaluate CSF shunt complication incidence and factors that may be associated with increased shunt dysfunction and infection rates in adults. METHODS: From January 1999 to December 2006, we conducted a prospective surveillance program for all neurosurgical procedures including reoperations and infections. Patients undergoing CSF shunt placement were retrospectively identified among patients labeled in the database as having a shunt as a primary or secondary intervention. Revisions of shunts implanted in another hospital or before the study period were excluded, as well as lumbo- or cyst-peritoneal shunts. Shunt complications were classified as mechanical dysfunction or infection. Follow-up was at least 2 years. Potential risk factors were evaluated using log-rank tests and stepwise Cox regression models. RESULTS: During the 8-year surveillance period, a total of 14 275 patients underwent neurosurgical procedures, including 839 who underwent shunt placement. One hundred nineteen patients were excluded, leaving 720 study patients. Mechanical dysfunction occurred in 124 patients (17.2%) and shunt infection in 44 patients (6.1%). These 168 patients required 375 reoperations. Risk factors for mechanical dysfunction were atrial shunt, greater number of previous external ventriculostomies, and male sex; risk factors for shunt infection were previous CSF leak, previous revisions for dysfunction, surgical incision after 10 am, and longer operating time. CONCLUSION: Shunt surgery still carries a high morbidity rate, with a mean of 2.2 reoperations per patient in 23.3% of patients. Our risk-factor data suggest methods for decreasing shunt-related morbidity, including peritoneal routing whenever possible and special attention to preventing CSF leaks after craniotomy or external ventriculostomy.

Risk factors for adult nosocomial meningitis after craniotomy: role of antibiotic prophylaxis.

OBJECTIVE: To evaluate incidence and risk factors of postoperative meningitis, with special emphasis on antibiotic prophylaxis, in a series of 6243 consecutive craniotomies. METHODS: Meningitis was individualized from a prospective surveillance database of surgical site infections after craniotomy. Ventriculitis related to external ventricular drainage or cerebrospinal fluid shunt were excluded. From May 1997 until March 1999, no antibiotic prophylaxis was prescribed for scheduled, clean, lasting less than 4 hours craniotomies, whereas emergency, clean-contaminated, or long-lasting craniotomies received cloxacillin or amoxicillin-clavulanate. From April 1999 until December 2003, prophylaxis was given to every craniotomy. Independent risk factors for meningitis were studied by a multivariate analysis. Efficacy of antibiotic prophylaxis in preventing meningitis was studied as well as consequences on bacterial flora. RESULTS: The overall meningitis rate was 1.52%. Independent risk factors were cerebrospinal fluid leakage, concomitant incision infection, male sex, and surgical duration. Antibiotic prophylaxis reduced incision infections from 8.8% down to 4.6% (P < 0.0001) but did not prevent meningitis: 1.63% in patients without antibiotic prophylaxis and 1.50% in those who received prophylaxis. Bacteria responsible for meningitis were mainly noncutaneous in patients receiving antibiotics and cutaneous in patients without prophylaxis. In the former, microorganisms tended to be less susceptible to the prophylactic antibiotics administered. Mortality rate was higher in meningitis caused by noncutaneous bacteria as compared with those caused by cutaneous microorganisms. CONCLUSION: Perioperative antibiotic prophylaxis, although clearly effective for the prevention of incision infections, does not prevent meningitis and tends to select prophylaxis resistant microorganisms.

Risk factors for adult nosocomial meningitis after craniotomy: role of antibiotic prophylaxis.

OBJECTIVE: To evaluate incidence and risk factors of postoperative meningitis, with special emphasis on antibiotic prophylaxis, in a series of 6243 consecutive craniotomies. METHODS: Meningitis was individualized from a prospective surveillance database of surgical site infections after craniotomy. Ventriculitis related to external ventricular drainage or cerebrospinal fluid shunt were excluded. From May 1997 until March 1999, no antibiotic prophylaxis was prescribed for scheduled, clean, lasting less than 4 hours craniotomies, whereas emergency, clean-contaminated, or long-lasting craniotomies received cloxacillin or amoxicillin-clavulanate. From April 1999 until December 2003, prophylaxis was given to every craniotomy. Independent risk factors for meningitis were studied by a multivariate analysis. Efficacy of antibiotic prophylaxis in preventing meningitis was studied as well as consequences on bacterial flora. RESULTS: The overall meningitis rate was 1.52%. Independent risk factors were cerebrospinal fluid leakage, concomitant incision infection, male sex, and surgical duration. Antibiotic prophylaxis reduced incision infections from 8.8% down to 4.6% (P < 0.0001) but did not prevent meningitis: 1.63% in patients without antibiotic prophylaxis and 1.50% in those who received prophylaxis. Bacteria responsible for meningitis were mainly noncutaneous in patients receiving antibiotics and cutaneous in patients without prophylaxis. In the former, microorganisms tended to be less susceptible to the prophylactic antibiotics administered. Mortality rate was higher in meningitis caused by noncutaneous bacteria as compared with those caused by cutaneous microorganisms. CONCLUSION: Perioperative antibiotic prophylaxis, although clearly effective for the prevention of incision infections, does not prevent meningitis and tends to select prophylaxis resistant microorganisms.

Diagnostic and therapeutic management of nosocomial pneumonia in surgical patients: results of the Eole study.

OBJECTIVE: To assess clinical, microbiological, and therapeutic features of nosocomial pneumonias in surgical patients. DESIGN: Prospective (October 1997 through May 1998), consecutive case series analysis of patients suspected of having pneumonia during the fortnight after a surgical procedure or trauma and receiving antibiotic therapy prescribed by the attending physician for this diagnosis. SETTING: A total of 230 study centers in teaching (n = 66) and nonteaching hospitals (n = 164) (surgical wards and intensive care units). PATIENTS: A total of 837 evaluable patients (mean age 61 +/- 18 yrs) including 629 intensive care unit patients. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: The diagnostic and therapeutic procedures followed were based on guidelines. Antibiotics and any changes of therapy and duration of treatment were decided by the attending physician. The charts were reviewed by a panel of experts that classified the cases according to clinical, radiologic, and microbiological criteria (when available). The efficacy of treatment was evaluated over a 30-day period following the index episode. The patients were classified into three groups: definite pneumonia (n = 261), possible pneumonia (n = 392), or low-probability pneumonia (n = 184). Ventilator-acquired pneumonia was reported in 303 patients. Early onset pneumonia was reported in 512 cases. Microbiological sampling was performed in 718 patients, by bronchoscopy in 367 cases, recovering 450 organisms in 328 patients, including 94 polymicrobial specimens. High proportions of Gram-negative bacteria and staphylococci were cultured, even in early onset pneumonias. Antibiotic therapy was administered for 13 +/- 4 days, using monotherapy in 254 cases. Changes in the initial antibiotic therapy (135 monotherapies) were decided in 517 patients (including clinical failure or persistent infection, n = 171; organisms resistant to initial therapy, n = 177; pulmonary superinfection, n = 68). Death occurred in 180 patients, related to pneumonia in 53 cases. CONCLUSIONS: Nosocomial pneumonias in surgical patients are characterized by high frequency of early onset pneumonia, high proportion of nosocomial organisms even in these early onset pneumonias, and moderate mortality rate.

Les abces et empyemes cerebreaux / Abscess and empyema of the brain

Brain abscess and subdural empyema are serious infections which can be metastasis of chronic suppurative diseases (bronchectasia, lung orabdominal abscess) or of congenital cardiopathy, but they are more frequently seen in healthy adults suffering from chronic sinusitis or otitis. Brain CT scan with contrast media injection is the best tool for diagnosis and follow-up. It has transformed the prognosis of brain abscesses. Anaerobic oropharyngeal microflora is the main source of bacteria responsible for suppurative brain diseases. Surgical treatment consist of aspiration or, rarely now, of excision of the lesion. Medical treatment alone can be successfull in selected cases, provided patients are closely monitored and antibiotics with good penetration into the brain parenchyma are used