No need for broad-spectrum empirical antibiotic coverage after surgical drainage of orthopaedic implant infections

Purpose

Empirical broad-spectrum antibiotic treatment for orthopaedic implant infections after surgical lavage is common practice while awaiting microbiological results, but lacks evidence.

Methods

This was a single-centre cohort study from 1996 to 2010 with a follow-up of two years.

Results

We retrieved 342 implant infections and followed them up for a median of 3.5 years (61 recurred, 18 %). Infected implants were arthroplasties (n = 186), different plates, nails or other osteosyntheses. The main pathogens were S. aureus (163, 49 methicillin-resistant) and coagulase-negative staphylococci (60, 45 methicillin-resistant). Median duration of empirical antibiotic coverage after surgical drainage was three days before switching to targeted therapy. Vancomycin was the most frequent initial empirical agent (147), followed by intravenous co-amoxiclav (44). Most empirical antibiotic regimens (269, 79 %) proved sensitive to the causative pathogen, but were too broad in 111 episodes (32 %). Cephalosporins and penicillins were used only in 44 and ten cases, respectively, although they would have covered 59 % of causative pathogens identified later. Multivariate Cox regression analysis showed that neither susceptible antibiotic coverage (compared to non-susceptible; hazard ratio 0.7, 95 % confidence interval 0.4–1.2) nor broad-spectrum use (hazard ratio 1.1, 0.8–1.5) changed remission rates.

Conclusions

Provided that surgical drainage is performed, broad-spectrum antibiotic coverage does not enhance remission of orthopaedic implant infections during the first three days. If empirical agents are prescribed from the first day of infection, narrow-spectrum penicillins or cephalosporins can be considered to avoid unnecessary broad-spectrum antibiotic use.     

The safety and efficacy of high-dose daptomycin combined with rifampicin for the treatment of Gram-positive osteoarticular infections

Purpose

Treatment of Gram-positive osteoarticular infections requires an adequate surgical approach combined with intensive antimicrobial therapy. The aim of this study was to evaluate the safety and efficacy of a combined regimen of high-dose daptomycin and rifampicin, in patients with various types of Gram-positive osteoarticular infections.

Methods

This single centre, non-comparative, prospective study evaluated the safety and efficacy of a combined regimen of intravenous daptomycin (8 mg/kg/day) and oral rifampicin (600 mg/day) in patients with Gram-positive osteoarticular infections, with a minimal follow-up of one year. Creatine phosphokinase, transaminases, bilirubinaemia, and serum creatinine, were measured at baseline and regular intervals.

Results

The median daily doses of daptomycin and rifampicin, administered for a median duration of 21 (range, 10–122) days to 16 patients (median age, 63.5 years; 11 males, five females) presenting with staphylococcal (n = 15) or streptococcal (n = 1) osteoarticular infections, were 8.15 (range, 6.6–8.9) mg/kg/day and 600 (range, 600–900) mg/day, respectively. The combined regimen of daptomycin and rifampicin was well tolerated by all except one patient, without requiring treatment adjustment or discontinuation. One patient developed allergic responses probably due to rifampicin after 42 days. Fifteen (94 %) patients showed favourable clinical and microbiological outcomes.

Conclusions

The combined regimen of high-dose daptomycin and rifampicin was well tolerated and may provide a useful alternative to standard glycopeptide therapy for Gram-positive osteoarticular infections.     

Resterilized Mesh in Repair of Abdominal Wall Defects in Rats

A variety of negative opinions about repeated usage of relatively expensive resterilized synthetic meshes have been considered. It had been stated that resterilized polypropylene meshes inhibits fibroblastic activity, decreases proliferative activity, and increases apoptosis in human fibroblast culture, in vitro. The purpose of this study is the in vivo evaluation of the resterilized mesh repairs of abdominal hernia defects in rat models of incisional hernia by comparing primer repair and original mesh repairs. The rats (n = 22) were separated into three groups. While the abdominal defect was repaired by primary suture in the control group (CG), the defects were repaired by original mesh (OG) or resterilized mesh (RG) in mesh-repaired groups. After 21 days, the rats were evaluated for tissue tensile strengths, tissue hydroxyproline levels, tissue inflammation, fibrosis, and apoptosis. Although the tensile strengths in OG and RG were significantly higher than those of CG (p <. 05 and p <. 05), there was no significant difference between two groups. The tissue hydroxyproline levels in OG and RG were also higher than those of CG. The difference was not significant between the two groups. The inflammation and fibrosis indexes in OG and RG were significantly higher than those of CG (p <. 0001 for both), but there was no difference between groups. While the apoptosis index in OG and RG was also higher than that of CG (p <. 0001 for both), there was no significant difference between OG and RG. The usage of resterilized mesh in abdominal wall repair did not reduce the tissue tensile strength, did not affect the tissue hydroxyproline levels, did not decrease the fibrosis, and did not increase the tissue inflammation and apoptosis. In conclusion, usage of resterilized meshes in abdominal wall defects was as safe as sterilized meshes.     

The Effects of Hyperbaric Oxygen Therapy on Colonic Anastomosis in Rats With Peritonitis

The aim of this study is to investigate the healing effect of hyperbaric oxygen (HBO) on colonic anastomoses in the presence of experimentally induced peritonitis. Thirty-two rats were allocated randomly into short-term anastomosis (STA), short-term anastomosis + HBO treatment (STA+HBO), long-term anastomosis (LTA), and long-term anastomosis + HBO (LTA+HBO) treatment groups. The STA and LTA groups were administered fluid resuscitation and antibiotics for 3 and 7 days, respectively, whereas the HBO treatment groups received additional HBO therapy for 3 and 7 days, respectively. The rats were reoperated on the third and the seventh days of anostomoses for evaluation. The bursting pressures in STA+HBO and LTA+HBO therapy groups were significantly higher than those in groups with anastomoses alone (p <. 001 and p <. 01). HBO therapy did not affect the fibrotic index neither in STA nor in LTA groups (p >. 05 for both); however, it was significantly higher in LTA+HBO group than that in STA+HBO group (p <. 05). The hydroxyproline level was significantly higher in LTA group than in STA group (p <. 05), yet HBO therapy did not affect the hydroxyproline levels in STA or LTA groups (p >. 05 for both). It is concluded that hyperbaric oxygen treatment has positive effects on colonic anastomotic healing in case of peritonitis.     

Neutrophil/lymphocyte ratio is associated with thromboembolic stroke in patients with non-valvular atrial fibrillation

BackgroundNeutrophil/lymphocyte ratio (NLR) has been associated with poor outcomes in patients with cardiovascular diseases. However, little is known about the role of NLR in patients with thromboembolic stroke due to atrial fibrillation (AF). We aimed to compare the NLR ratios between non-valvular AF patients with or without thromboembolic stroke.MethodsA total of 126 non-valvular AF patients with or without stroke were included in the study; 126 consecutive patients (52 males and 74 females), mean age, 70 ± 10.2 years old. No patient had a recent history of an acute infection or an inflammatory disease. Baseline NLR was measured by dividing neutrophil count to lymphocyte count. WBC count > 12.000 cells per μL or < 4.000 cells per μL and high body temperature > 38 º are excluded from the study.ResultsMean NLR was significantly higher among persons with stroke compared to individuals without a stroke (5.6 ± 3.4 vs. 3.1 ± 2.1, p = 0.001). There were no significant differences in RDW levels between the two groups (p > 0.05). HAS-BLED and CHADS₂ scores were significantly higher in the stroke group.ConclusionHigher NLR, an emerging marker of inflammation, is associated with thromboembolic stroke in non-valvular AF patients.     

Evaluation of selective human MAO inhibitory activities of some novel pyrazoline derivatives

A series of 1-[2-((5-methyl/chloro)-2-benzoxazolinone-3-yl)acetyl]-3,5-diaryl-4,5-dihydro-1H-pyrazole derivatives were prepared by reacting 2-((5-methyl/chloro)-2-benzoxazolinone-3-yl)acetylhydrazine with appropriate chalcones. The chemical structures of all compounds were confirmed by elemental analyses, IR, ¹H NMR and ESI–MS. All the compounds were investigated for their ability to selectively inhibit monoamine oxidase (MAO) by in vitro tests. MAO activities of the compounds were compared with moclobemide and selegiline and all the compounds were found to inhibit human MAO-A selectively. The inhibition profile was found to be competitive and reversible for all compounds by in vitro tests. Among the compounds examined, compounds 5ae, 5af and 5ag were more selective than moclobemide, with respect to the K _i values experimentally found. In addition, the compound 5bg showed MAO-A inhibitor activity as well as moclobemide. A series of experimentally tested compounds (5ae–5ch) were docked computationally to the active site of the MAO-A and MAO-B isoenzyme. The AUTODOCK 4.01 program was employed to perform automated molecular docking.     

Solitary median maxillary central incisor: a report of 2 cases

A single median maxillary central incisor (SMMCI) is a rare dental anomaly that may occur alone or be associated with growth deficiency or other systemic abnormalities. The best known association is with holoprosencephaly (HPE). HPE is a complex brain malformation that affects both the forebrain and the face. Early diagnosis of SMMCI is important, since it may be a sign of other severe congenital or developmental abnormalities. Therefore, systematic follow-up and close monitoring of the growth and development of SMMCI patients is crucial. The purpose of this paper was to report the cases of 2 children, each with a single median maxillary central incisor, and describe important symptoms of this syndrome that have not yet been reported.