196,215 research outputs found
Evaluation of amoxicillin plasma and tissue levels in pediatric patients undergoing tonsillectomy
No full textOBJECTIVE:
Tonsillectomy is the most common surgery performed in the pediatric and young adult populations. Although recent guidelines based on meta-analysis suggest that perioperative chemoprophylaxis plays a role in reducing bacteraemia-related post-tonsillectomy complications, there is no evidence or agreement upon which specific antibiotic, dosage or administration route should be preferred. Since few previous studies have assessed the effectiveness of prophylaxis by direct measurement of antibiotic levels both in plasma and tissue, we designed an experimental study to quantitatively evaluate amoxicillin concentrations in children ready for tonsillectomy and compare these plasma and tissue levels with the Minimal Inhibitory Concentrations (MIC) of the bacteria more commonly involved in the upper airway infections.
METHODS:
Thirty-three pediatric patients under 14 years of age (median 5.0, IQR 4-7, range 3-11; M:F 18:15) with recurrent tonsillitis were treated with 3 doses (established on patient's weight) of amoxicillin-clavulanic acid given orally the day before plus a further dose 2h before tonsillectomy. Amoxicillin concentrations on both homogenated tonsillar cores and plasma were measured by HPLC-UV. Bacterial epidemiology and susceptibility were derived respectively from survey data collected by Microbiology Unit and MIC according to the National Committee for Clinical Laboratory Standards (NCCLS).
RESULTS:
Median plasma and tissue amoxicillin concentrations were respectively 4.7 microg/ml (IQR 2.1-8.0; min-max 0.4-14.3) and 1.1 microg/g (IQR 0.4-2.1; min-max 0.4-12.9), considerably below the selected target MIC of pathogens involved in the upper respiratory tract infections (S. aureus, H. influenzae, M. catarrhalis). 20 Children showed undetectable amoxicillin levels in one or both tonsils. Interestingly, 7 out of these patients (35%) had plasma concentrations higher than the target MIC (8 microg/ml). No patient displayed plasma concentrations under the limit of sensitivity of the method. Poor core-plasma and left-right core correlation was observed among patients, suggesting that fibrosis developed after recurrent tonsillitis may hamper antibiotic penetration.
CONCLUSIONS:
Based upon direct measurement of antibiotic levels in plasma and tissue, this study suggests that a revision of the oral prophylaxis in children is required in order to reduce microbial charge in the operative field and accordingly improve the recovery after tonsillectomy.
Copyright 2010 Elsevier Ireland Ltd. All rights reserved
Amoxicillin in tonsillectomy: preliminary data on the evaluation of serum and tissue concentrations
No full textPost-thyroidectomy superior laryngeal nerve injury.
No full textVoice dysfunction after thyroidectomy may be caused by damage to laryngeal nerves or lesions to strap muscles with laryngo-tracheal movement impairment. Injury to an external branch of the superior laryngeal nerve (EBSLN) is sometimes difficult to recognize clinically and its electromyographic incidence ranges from 0% to 58%. In this study we evaluated, 12-18 months postoperatively, 45 patients who had undergone thyroid surgery (6 total lobectomy, 5 subtotal thyroidectomy, and 34 total thyroidectomy), using a subjective interview, laryngeal videostroboscopy and spectrographic analysis with a multidimensional voice program. Vocal parameters included fundamental frequency, jitter, shimmer, noise-to-harmonic-ratio (NHR) and degree of sub-harmonics. Laryngeal electromyography (LEMG) of the cricothyroid (CT) muscles was performed in 21 subjects with voice problems (35 EBSLNs) using a modified method for the CT recording. In 3 patients of this group (14%) LEMG documented a unilateral EBSLN injury. Easy voice fatigue and decreased pitch range were the most common symptoms after surgery. Average values of vocal parameters pre- and postoperatively in patients without neural damage (n = 42) were: jitter 0.64% and 0.78%, shimmer 3.25% and 3.54%, and NHR 0.12% and 0.13%, respectively (P > 0.05). Acoustic analysis revealed altered patterns in some patients with no objective evidence of damage to EBSLNs, suggesting an extralaryngeal cause of vocal dysfunction, such as laryngo-tracheal fixation or lesions to strap muscles. We conclude that laryngeal videostroboscopy and spectrographic analysis are very useful to assess voice problems after thyroidectomy, including in patients without LEMG-proven neural lesions, in order to suggest early speech rehabilitation, especially in professional voice users
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