Treatment of experimental osteomyelitis by liposomal antibiotics

Objectives: Traditional antibiotic therapy of staphylococcal osteomyelitis by a single drug or a drug combination is ineffective in producing complete sterilization of infected bones. The aim of this study was to develop a non-traditional delivery system of antibiotics for treatment of chronic experimental osteomyelitis. Methods: In the current work, ciprofloxacin and vancomycin were encapsulated in a cationic, anionic or neutral liposomal formulation. For prolonged circulation in serum, liposomal dispersions (<100 nm in diameter) were sonicated for different times (20, 40, 60 or 80 s), and tested for antibacterial activities. Results and conclusions: Liposomes sonicated for 40 s gave the highest antibacterial activities in vitro. Since cationic liposomes trapped the highest percentage of antibiotics, and enhanced antibacterial activity above that of the free drugs, they were used for therapeutic trials to treat chronic staphylococcal osteomyelitis induced in rabbits. Therapeutic trials with antibiotics given intravenously revealed that, free ciprofloxacin or vancomycin given alone for 14 days was ineffective in sterilizing bone. Combination therapy with free ciprofloxacin and vancomycin for 14 days was more effective. However, this group showed renal dysfunction and severe diarrhoea, which resulted in loss of 33.3% of treated animals. Treatment with liposomal forms of either drug for 7 days was ineffective. Meanwhile, combination therapy in liposomal form for 7 days was more effective. Complete sterilization of bone tissues on cultures (100% cure) was obtained only in the group treated for 14 days with the combination of both drugs in liposomal form. Moreover, liposomal formulations showed much lower nephrotoxicity and a lower incidence of severe diarrhoea than that induced by free drugs

The role of tracheal tube introducers and stylets in current airway management.

Tracheal tube introducers and stylets are highly successful devices for the management of various airway scenarios. Their first-line use is advocated in many difficult airway algorithms. Although they have been used for decades, the shape and design of introducers and stylets as well as their patterns of use are constantly evolving. Our purpose is to provide the clinician with an update on these different devices. We performed a systematic literature search from 2005 until May 2015, without language restrictions. The two authors independently retrieved all studies with the keywords "bougie", "gum elastic bougie", "stylet", "airway management", "tracheal tube introducer" and "extubation catheter". Our search did yield mostly observational and retrospective studies with small case numbers. The data was synthesized into a narrative review to provide the clinician with an update on the characteristics, indications and techniques of use as well as the dangers of different intubation aids. Today, numerous tracheal tube introducers and stylets exist with different indications, ranging from general to specific situations. Anesthetists should be familiar with the different devices, their characteristics and indications in order to use the right device at the right time in the right way

Peri-operative Medication Dosing in Adult Obese Elective Surgical Patients: A Systematic Review of Clinical Studies

Background: Despite the increasing numbers of obese patients undergoing elective surgery, there is a lack of evidence-based dosing guidelines for peri-operative medications in obesity. Objective: The objective was to systematically review the dosing and outcomes of peri-operative medications used in obese elective surgical patients. Methods: Medical subject headings and general keywords were used to systematically search multiple databases (PubMed, EMBASE, Cochrane Library and CINAHL). Studies of medications in obese surgical patients were included if they had a non-obese control or comparative dosing scalar group. The National Health and Medical Research Council GRADE tool was used to assess quality of evidence for each drug. Results: Thirty-three studies of six drug classes were identified: anaesthetics (n = 6), muscle relaxants (n = 10), neuromuscular reversal agents (n = 3), analgesics (n = 2), antibiotics (n = 5) and anticoagulants (n = 7). A variety of dose scalars and/or recommendations was observed for various medications. Lean body weight was proposed as a suitable weight scalar for induction of anaesthesia with propofol whereas total body weight for maintenance of anaesthesia with propofol and depolarizing muscle relaxants. Ideal body weight was reported as an appropriate dosing scalar for non-depolarizing muscle relaxants and neuromuscular reversal agents. Both corrected body weight 40% and ideal body weight were reported as suitable weight scalars for post-operative analgesia with morphine. The standard 2-g dose of cefazolin appeared effective in the prevention of surgical site infection. Body mass index stratified dosing of enoxaparin was effective for venous thromboembolism prevention. Conclusion: No drug recommendation achieved an “Excellent” quality of evidence. Limited data suggest that clinicians should consider each individual class of medication when selecting a dose for obese surgical patients. Routine use of fixed-dosing regimens is likely to under- or overdose obese patients thus predisposing them to adverse drug events or treatment failure leading to patient harm