Prospective, randomised clinical trial of four different presurgical hand antiseptic techniques in equine surgery.

BACKGROUND: Currently, the World Health Organization recommends the use of alcohol-based hand rubs (ABR) for surgical hand preparation in human surgery. When disinfecting soaps are used, a rubbing technique causes less skin irritation than brush scrubbing. Based on a recent survey, most equine surgeons still use disinfecting soap. The efficacy of scrubbing vs. rubbing and the use of sole ABR compared with chlorhexidine (CHx)- based products has not been evaluated in the equine surgical setting. OBJECTIVES: To compare four surgical hand antisepsis techniques in equine surgery for reduction of aerobic bacterial counts from pre- to post-preparation (immediate efficacy) and at the end of surgery (sustained efficacy). STUDY DESIGN: Randomised, prospective clinical trial. METHODS: A 4% CHx-based product applied with either a scrub or rub technique, one sole ABR (ET; 80% ethanol) and one CHx/alcohol-combination (CHx/ET; 1% CHx and 61% ethanol) product both applied with a rub technique were evaluated. Samples were collected by glove juice technique and cultured on 3M™ Petrifilm plates and counted using a 3M™ Petrifilm plate reader. RESULTS: Immediate mean bacterial log10 colony forming unit (CFU) reduction was 2.4 for CHx-scrub, 2.8 for CHx-rub, 3.1 for CHx/ET and 2.1 for ET. CHx/ET resulted in significantly lower bacterial counts than CHx-scrub (P<0.005) and ET (P<0.001) while CHx-rub resulted in significantly lower counts than ET (P<0.001). At the end of surgery bacterial counts were the lowest for CHx-rub, significantly lower than CHx/ET (P<0.001) and ET (P<0.001). There was no difference between CHx-rub and -scrub techniques (P = 0.7). MAIN LIMITATIONS: Bacterial counts were used as the outcome measure rather than prevalence of surgical site infection, and the effect of hand preparation on skin health was not assessed. CONCLUSIONS: ABR did not decrease bacterial log10 CFU counts more effectively than CHx products. When using CHx soaps in the equine setting, hand-rub is as effective as a hand-scrub-technique.

Physicochemical Approach to Determine the Mechanism for Acid-Base Disorders in 793 Hospitalized Foals.

BACKGROUND: The quantitative effect of strong electrolytes, unmeasured strong anions (UAs), pCO2, and plasma protein concentrations in determining plasma pH can be demonstrated using the physicochemical approach. Plasma anion gap (AG) and strong ion gap (SIG) are used to assess UAs in different species. HYPOTHESES: Strong ions are a major factor influencing changes in plasma pH of hospitalized foals. AG and SIG accurately predict severe hyper-L-lactatemia ([L-lac(-)] > 7 mmol/L). ANIMALS: Seven hundred and ninety three hospitalized foals < 7 days old. METHODS: Retrospective study. The relationship between measured pH and physicochemical variables, and the relationship between plasma [L-lac(-)] and AG and SIG, were determined using regression analyses. Optimal AG and SIG cut points to predict hyper-L-lactatemia were identified using an ROC curve analysis. RESULTS: Combined, the measured strong ion difference and SIG accounted for 54-69% of the changes in the measured arterial pH of hospitalized foals. AG and SIG were significantly associated with plasma [L-lac(-)] (P < .0001). The receiver operator characteristics (ROC) AUC of AG and SIG for prediction of severe hyper-L-lactatemia were 0.89 (95%CI, 0.8-0.95; P < .0001) and 0.90 (95%CI, 0.81-0.96; P < .0001), respectively. Severe hyper-L-lactatemia was best predicted by AG > 27 mmol/L (sensitivity 80%, 95%CI, 56-94, specificity 85%, 95%CI, 73-93; P < .0001) and SIG <-15 mmol/L (sensitivity 90%, 95%CI, 68-98; specificity 80%; 95%CI, 68-90; P < .0001). CONCLUSION AND CLINICAL RELEVANCE: Altered concentrations of strong ions (Na(+), K(+), Cl(-)) and UAs were the primary cause of acidemia of hospitalized foals. AG and SIG were good predictors of hyper-L-lactatemia and could be used as surrogate tests.