Are surgical scrubbing and pre-operative disinfection of the skin in orthopaedic surgery reliable?

This study attempts to establish the actual effectiveness of pre-surgical disinfection of the patient and surgeon's hands. We evaluated bacterial density and composition on the skin of 15 patients undergoing knee arthroscopy and the left hand of two surgeons after standard disinfection with povidone-iodine. Three samples were taken after the first 6-min scrub in the first surgical operation from the periungual space of the 1 degrees finger, from the interdigital space between the 2 degrees and 3 degrees fingers and from the transverse palmar crest of the left hand of two surgeons for seven consecutive surgical sessions, for a total of 42 samples, and two samples from the pre-patellar skin and from the popliteal skin of 15 patients undergoing knee arthroscopy, for a total of 30 samples. Pre-surgical handwashing and disinfection procedures were identical in each case. Pre-surgical disinfection of the patient's skin with povidone-iodine was shown to be completely effective, with 100% of samples negative. Samples taken from the interdigital space and the palmar crest (100% of samples negative) demonstrated the efficacy of disinfection of the surgeon's hands with povidone-iodine, while the periungual space was contaminated in 50% of the samples. The bacterial strains isolated belong to the staphylococcus genus in 100% of the cases, with pathogenic strains in 29.6% of the cases. Standard pre-surgical disinfection of skin in areas easily accessible to the disinfectant is sufficient in itself to guarantee thorough sanitization. Standard scrubbing of the surgeon's hands is insufficient in eliminating bacterial contamination, including pathogenic germs, in the periungual space, where it is probably difficult for the disinfectant to come into contact with the skin.

Deep sedation for magnetic resonance imaging. Personal experience.

AIM: Precision in diagnostic procedure and examination of paediatric patients often requires their absolute immobility. Deep sedation has proven to be an excellent method, allowing optimum technical quality of MRI particularly in younger age groups. The aim of study is to demonstrate the possible application of deep sedation through the use of 2 safe and manageable drugs. METHODS: We carefully evaluated and selected 82 patients (47 males and 35 females; average age 5.4 years): they came from various paediatrics departments. Deep sedation was practiced with: Chloral hydrate (60-80 mg/kg in one oral administration); propofol as intravenous bolus (2-2.5 mg/kg) followed by a maintenance infusion of 75-125 microg/kg/min. This was preceded by midazolam (0.05 mg/kg i.v.) outside the MRI room. Oxygen saturation (SpO2) was monitored in all patients along with heart rate in order to foresee the need for any possible therapeutic intervention. RESULTS: The sedation levels attained permitted the success of MRI assuring the immobilization required. Manually assisted mask ventilation was required for a period of 2-3 min in 5 patients treated with propofol. All other patients breathed autonomously. Complete reawakening occurred within 2 hours of drug administration. Surveillance was prolonged inside their respective units, however, without registering delayed side effects. CONCLUSION: The central point of the success of deep sedation is to define the type and dose of optimum drug for individual patients. This requires a qualified, expert group ready to intervene in the presence of adverse results of drugs administered. Propofol and chloral hydrate are the optimum drugs for diagnostic techniques requiring total immobilization and rapid reawakening.

[The nitric oxide metabolism in the hypoxic, ischemic and reperfused human skeletal muscle cell: clinical and therapeutical observations]. / L'ossido nitrico nella cellula muscolare umana ischemica e riperfusa: connessioni cliniche e terapeutiche.

BACKGROUND: The biochemical and metabolic role played by nitric oxide (NO) in course of oxidative stress due to cell hypoxia, ischemia and reperfusion has a determinant relevance in the mitochondrial adaptive changes which antagonize the irreversible morpho-functional damage. In particular conditions, such as in prolonged ischemia and/or exogenous NO supplementation, this element is present in the radical form (NOO*) concurring to peroxidative cell injury. Aim of this study was to investigate these opposite NO aspects in hypoxic, ischemic and reperfused human skeletal muscle tissue. METHODS: Skeletal muscle samples were taken during elective knee orthopedic surgery in 10 consecutive patients. The biopsies were obtained before, after 5+/-1 min and 58+/-2 min from tourniquet application and then after 18+/-3 min following muscle reperfusion. The samples, immediately frozen in liquid nitrogen, were assayed for endocellular free NO following the gas-amperometric method described by Palmerini C. RESULTS: When compared with normoxic tissues, a significant decrease in free NO content was observed in hypoxic samples. After about 60 min of prolonged ischemia the NO levels show an evident increase, while the tissue reperfusion leads to a progressive restoration of physiological content in the cellular free nitric oxide. CONCLUSIONS: The obtained data in hypoxic muscle cell seem to underline the pivotal role played by NO in adapting the cytochrome c oxidase oxidative activity to lower O2 bio-availability. On the other hand the prolonged ischemia leads to a consistent NOO* generation triggered by oxyradical generation and Ca2+ intracellular over load. Even if the tissue reoxygenation restores the normal NO levels it is arguable that the pre-treatment of ischemic cell with antioxidants, Ca-antagonist and Dexamethasone supplementation could represent a crucial and specific therapeutic approach to critically ill patient.

[Biochemical and metabolic aspects of oxyradical pathology in the hypoxic-ischemic reperfused human skeletal muscle tissue. Clinical markers and therapeutic approach]. / Aspetti biochimici e metabolici della patologia ossiradicalica nel muscolo scheletrico umano ipossico-ischemico-riperfuso. Parametri valutativi nella clinica e nella terapia del paziente critico.

BACKGROUND: Following our previous studies on the biomolecular and biochemical aspects of the human tissue oxidative damage due to hypoxia, ischemia and reperfusion, aim of the present work is to evaluate the role played by oxyradical generation in the morphofunctional cellular injury. We evaluated the tissue levels of some metabolic markers (MDA, Catalase, Uric Acid) to obtain a pathogenic picture and then a therapeutic approach closely related to the cellular biodynamics. METHODS: A skeletal muscle samples were taken during elective knee orthopedic surgery in 20 consecutive patients. The biopsies were taken in normoxic conditions and after 5 +/- 1 and 62 +/- 3 min form tourniquet application and finally 21 +/- 2 min following muscle reperfusion. The samples were assayed for tissue Malondialdeyade (MDA), uric acid and catalase (CAT) contents with HPLC and fluorimetric procedures. All data were evaluated in terms of computerized statistical analysis. RESULTS: When compared to normoxic tissue (1.24 +/- 0.26 nmoli.mg-1 protein), the MDA levels show a moderate increase in hypoxic (1.66 +/- 0.12) and ischemic tissue (1.78 +/- 0.13), while highly significant is the rise in reperfused muscle MDA content (5.94 +/- 0.15). The uric acid as far as CAT shows no appreciable alterations in hypoxia and ischemia. Following reoxygenation an increase in uric acid contents with a concomitant CAT tissue consumption appear evident. CONCLUSIONS: The obtained data seem to underline the cytoprotective role played by adaptive changes in the hypoxic and ischemic human cells. On the contrary, the rapid reoxygenation of the ischemic tissue appears to start oxyradical neo-generation. In clinical and therapeutic terms these observations underline a peculiar and different approach to the critically ill patient.