Vacuum-assisted closure for deep infection after spinal instrumentation for scoliosis.

Our aim was to review the efficacy of the wound vacuum-assisted closure (VAC) system in the treatment of deep infection after extensive instrumentation and fusion for spinal deformity in children and adolescents. A total of 14 patients with early deep spinal infection were treated using this technique. Of these, 12 had neuromuscular or syndromic problems. Clinical and laboratory data were reviewed. The mean follow-up was 44 months (24 to 72). All wounds healed. Two patients required plastic surgery to speed up the process. In no patient was the hardware removed and there was no loss of correction or recurrent infection. We believe that the wound VAC system is a useful tool in the armamentarium of the spinal surgeon dealing with patients susceptible to wound infections, especially those with neuromuscular diseases. It allows for the retention of the instrumentation and the maintenance of spinal correction. It is reliable and easy to use.

Delayed infections after posterior TSRH spinal instrumentation for idiopathic scoliosis: revisited.

OBJECTIVE: To determine the incidence of delayed infections in idiopathic scoliosis treated with TSRH instrumentation, proper wound management after instrumentation removal, and whether the previously identified bacterial trend remains consistent. METHODS: All patients with idiopathic scoliosis > or =2 years after surgery with posterior TSRH instrumentation were included. Those cases with delayed infections were retrospectively reviewed. Time of presentation (infection) from index operation, clinical picture, sedimentation rate, presence of pseudarthrosis, organisms grown on culture, type of wound closure, and duration of antibiotics were examined. RESULTS: A total of 489 patients were identified > or =2 years postoperation; 23 had delayed infections (4.7%). Time of presentation averaged 27 months after initial surgery. Spontaneous drainage occurred in 15 patients, fluctuance in 6, and neither in the remaining 2 (pain and fever). Sedimentation rate averaged 48 mm/hr. All patients had instrumentation removed. Primary closure (1 stage) was performed in 14 patients, and delayed primary closure (> or =2 stages) was performed in nine patients. All wounds healed uneventfully. Cultures at the time of instrumentation removal grew Propionibacterium acnes in 12 patients, Staphylococcus epidermidis (or Staphylococcus coagulase-negative) in 4, Micrococcus varians in 1, and Staphylococcus aureus in 1. Five patients had negative cultures. After removal, patients received parenteral antibiotics; in 21 of these patients this was followed by oral antibiotics. CONCLUSIONS: Low-virulent skin organisms are primarily responsible for delayed infections. Intraoperative seeding followed by subclinical quiescent periods appears to be the method by which infection occurs. The increased bulk and modularity of modern instrumentation systems can lead to inflammation and bursa formation, thus contributing significantly to the activation of these infections. Primary wound closure results in successful wound healing. Delayed closure after 48 hours is unnecessary. Short-term postoperative parenteral antibiotics (2-5 days) followed by short-term oral antibiotics (7-14 days) is recommended.

Analysis of some antifungal drugs by spectrophotometric and spectrofluorimetric methods in different pharmaceutical dosage forms.

Simple spectrophotometric and spectrofluorimetric methods are suggested for the determination of antifungal drugs; clotrimazole, econazole nitrate, ketoconazole, miconazole and tolnaftate. Spectrophotometric one depends on the interaction between imidazole antifungal drugs as n-electron donor with the pi acceptor 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in methanol or with p-chloranilic acid (p-CA) in acetonitrile. The produced chromogens obey Beer's law at lambda(max) 460, and 520 nm in the concentration range 22.5-200 and 7.9-280 microg ml(-1) for DDQ, and p-CA, respectively. Spectrofluorimetric method is based on the measurement of the native fluorescence of ketoconazole at 375 nm with excitation at 288 nm and or the induced fluorescence after alkaline hydrolysis of tolnaftate with 5 M NaOH solution at 420 nm with excitation at 344 nm. Fluorescence intensity versus concentration is linear for ketoconazole at 49.7-800 ng ml(-1) while for tolnaftate, it is in the range of 20.4-400 ng ml(-1). The proposed methods were applied successfully for the determination of all the studied drugs in their pharmaceutical formulations.

The polarographic behaviour of ketoprofen and assay of its capsules using spectrophotometric and voltammetric methods.

The quantitative determination of ketoprofen using spectrophotometric and voltammetric methods are described. The spectrophotometric procedure depends upon the reaction of ketoprofen with N-bromosuccinimide (NBS). The residual reagent is then determined by formation of violet colour with 2,2-diphenyl-l-picryl hydrazine (DPPH(2)). The consumed NBS would correspond to ketoprofen. Beer's law is valid over the concentration range 5-80 mug/ml of the drug. Direct current (DC) polarography allows to study the reduction behaviour of ketoprofen at the dropping mercury electrode (DME) using different supporting electrolytes at different pH values. Direct current stripping voltammetry (DCSV) was used for the quantitative measurements of the drug. The calibration graph of peak current vs concentration was linear from 0.254 x 10(-2) to 0.254 mug/ml. In model solutions as little as 5.08 x 10(-4) ng/ml ketoprofen can be detected by DCSV. Both methods were applied successfully for the determination of ketoprofen either in pure or dosage forms.

Colorimetric determination of isoniazid and its pharmaceutical formulations.

Two colorimetric methods for the estimation of isoniazid are developed. The first method depends on coupling of isoniazid with diazotized 1-amino anthraquinone zinc chloride salt (fast red AL salt) to form a red colour (lambda(max) 510 nm). The second one is based on the formation of a green complex (lambda(max) 655 nm) between the acid hydrazide and 2,6-dimethoxy-1,4-benzoquinone (DMBQ). All measurements of the two procedures were carried out in the presence of sodium hydroxide at room temperature (20 +/- 3 degrees C). The two methods are applied for the determination of isoniazid in presence of congenial drugs, vitamins and additives normally encountered with it in pharmaceutical dosage forms. The reliability of these methods was established by parallel determination with the reported and official methods.

Spectrophotometric determination of tetracycline and oxytetracycline in pharmaceutical preparations.

A simple, rapid and sensitive spectrophotometric procedure for the assay of tetracycline hydrochloride and oxytetracycline hydrochloride has been developed. 2,2-Diphenyl-l-picrylhydrazyl (DPH), an intensely violet-coloured stable free radical, is changed in colour on reaction with the antibiotics investigated. The decrease in the intensity of the violet colour is used to measure the concentration of the drug. All measurements are made at 520 nm on methanolic solutions of the drug and reagent, buffered at pH 6. Beer's law is obeyed in the concentration ranges 2.5-15 and 2.5-20 mug/ml for tetracycline and oxytetracycline respectively. The proposed method has been successfully applied to analysis of the bulk drugs and their pharmaceutical formulations.

Determination of phenyltoloxamine salicylamide, caffeine, paracetamol, codeine and phenacetin by HPLC.

A reversed-phase high-performance liquid chromatographic method for the determination of six common analgesics (phenyltoloxamine dihydrogen citrate, salicylamide, caffeine, paracetamol, codeine phosphate and phenacetin) is presented. The method is specific for detection and determination of each of these compounds in a complex mixture, without pretreatment. A 10-mum C(18) silica gel stationary phase is used with a methanol-acetonitrile-water-tetrahydrofuran mixture (20:20:55:5 v/v) and spectrophotometric detection at 254 nm. All six components are eluted within 7 min. The method has given good results for three commercial products containing two, three and five active ingredients respectively. Phenacetin, a common analgesic which might be found in other formulations, is used as an internal standard.