Exploring patient acceptability of a short-stay care pathway in hospital post arthroplasty: A theory-informed qualitative study.

INTRODUCTION: Arthroplasty is an effective, yet costly, surgical procedure for end-stage osteoarthritis. Shorter stays in hospital are being piloted in Australia. In some countries, short stay is established practice, associated with improving perioperative care and enhanced recovery after surgery practices. Exploring the acceptability to patients of a short stay care pathway in hospital postarthroplasty is important for informing health policy, adoption and potential scalability of this model of care. METHODS: Consecutive patients at one site, at least 3 months post total joint arthroplasty, were invited to participate in theory-informed semi-structured qualitative interviews. The Theoretical Framework of Acceptability (TFA) informed development of the interview guide. Interview data were analysed using the Framework Method. RESULTS: Eighteen patients were invited. Fifteen consented to be contacted and were interviewed. Short-stay post arthroplasty was highly acceptable to patients who had the supports necessary to recover safely at home. Key findings were as follows: flexibility of short-stay care pathway was essential and valued; prior beliefs and expectations informed acceptability; and the absence of out-of-pocket expenses had an incentivizing effect, but was not the primary reason for patients choosing this care pathway. Further themes analysed within the TFA constructs highlighted nuances of acceptability relating to this model of care. CONCLUSIONS: A short stay in hospital post arthroplasty appeared to be acceptable to patients who had experienced this care pathway. Our thematic findings identified aspects of the short-stay care pathway that enhanced acceptability and some aspects that limited acceptability. These findings can inform refinement of the short-stay care pathway. PATIENT OR PUBLIC CONTRIBUTION: Patients/people with lived experience were not involved in the study design or conduct of this preliminary work; as this short-stay model of care was recently introduced, only a small group of patients was eligible to participate in this study. This study is the first step towards understanding the experiences of patients about a short-stay model of care post arthroplasty. The findings will help inform future patient and public involvement in expanding the programme.

Plasma and Interstitial Fluid Pharmacokinetics of Prophylactic Cefazolin in Elective Bariatric Surgery Patients.

Guidelines for surgical prophylactic dosing of cefazolin in bariatric surgery vary in terms of recommended dose. This study aimed to describe the plasma and interstitial fluid (ISF) cefazolin pharmacokinetics in patients undergoing bariatric surgery and to determine an optimum dosing regimen. Abdominal subcutaneous ISF concentrations (measured using microdialysis) and plasma samples were collected at regular time points after administration of cefazolin 2 g intravenously. Total and unbound cefazolin concentrations were assayed and then modeled using Pmetrics. Monte Carlo dosing simulations (n = 5,000) were used to define cefazolin dosing regimens able to achieve a fractional target attainment (FTA) of >95% in the ISF suitable for the MIC for Staphylococcus aureus in isolates of ≤2 mg · L-1 and for a surgical duration of 4 h. Fourteen patients were included, with a mean (standard deviation [SD]) bodyweight of 148 (35) kg and body mass index (BMI) of 48 kg · m-2. Cefazolin protein binding ranged from 14 to 36% with variable penetration into ISF of 58% ± 56%. Cefazolin was best described as a four-compartment model including nonlinear protein binding. The mean central volume of distribution in the final model was 18.2 (SD 3.31) L, and the mean clearance was 32.4 (SD 20.2) L · h-1. A standard 2-g dose achieved an FTA of >95% for all patients with BMIs ranging from 36 to 69 kg · m-2. A 2-g prophylactic cefazolin dose achieves appropriate unbound plasma and ISF concentrations in obese and morbidly obese bariatric surgery patients.

Prophylactic Cefazolin Dosing in Women With Body Mass Index >35 kg·m-2 Undergoing Cesarean Delivery: A Pharmacokinetic Study of Plasma and Interstitial Fluid.

BACKGROUND: Obesity is a risk factor for surgical site infection after cesarean delivery. There is inadequate pharmacokinetic data available regarding prophylactic cefazolin dosing in obese pregnant women. We aimed to describe the plasma and interstitial fluid (ISF) pharmacokinetics of cefazolin in obese women undergoing elective cesarean delivery and use dosing simulations to predict optimal dosing regimens. METHODS: Eligible women were scheduled for elective cesarean delivery at term, with a body mass index (BMI) of >35 kg·m. Plasma and ISF samples were collected following 2 g of intravenous cefazolin. Concentrations were determined using liquid chromatography-mass spectrometry. Population pharmacokinetic modeling and Monte Carlo dosing simulations were performed using Pmetrics. Total and unbound cefazolin concentrations in plasma and ISF were compared with the minimum inhibitory concentration at which 90% of isolates are inhibited (MIC90) of cefazolin for Staphylococcus aureus, 2 mg·L. The fractional target attainment (FTA) of dosing regimens to achieve a pre-established target of 95% unbound ISF concentrations >2 mg·L throughout a 3-hour duration of the surgery was calculated. RESULTS: The 12 women recruited had a median (interquartile range [IQR]) BMI of 41.5 (39.7-46.6) kg·m and a median (IQR) gestation of 38.7 weeks (37.9-39.0). For each timepoint up to 180 minutes, the median across subjects of total and unbound plasma concentration of cefazolin remained above 2 mg·L. The minimum observed total plasma concentration was 31.7 mg·L and plasma unbound concentration was 7.7 mg·L (observed in the same participant). For each timepoint up to 150 minutes, the median across subjects of unbound ISF concentrations remained above 2 mg·L. The minimum observed unbound ISF concentration was 0.7 mg·L (observed in 1 participant). In 2 participants, the ISF concentration of cefazolin was not maintained above 2 mg·L. The mean (± standard error [SE]) penetration of cefazolin (calculated as area under the concentration-time curve for the unbound fraction of drug [fAUC]tissue/fAUCplasma) into the ISF was 0.884 ± 1.11. Simulations demonstrated that FTA >95% was achieved in patients weighing 90-150 kg by an initial 2 g dose with redosing of 2 g at 2 hours. FTA was improved to >99% when an initial 3 g dose was repeated at 2 hours. CONCLUSIONS: To maintain adequate ISF antibiotic concentrations in obese pregnant women, our results suggest that redosing of cefazolin may be required. When wound closure has not occurred within 2 hours, redosing is suggested, following either a 2 or 3 g initial bolus. These preliminary results require validation in a larger population.

Outcomes and prognostic factors for patients with acute myeloid leukemia admitted to the intensive care unit.

Patients receiving treatment for acute myeloid leukemia (AML) commonly experience life-threatening complications requiring intensive care unit (ICU) support. This is a retrospective study of 505 patients with newly diagnosed AML who were treated with intensive chemotherapy between January 1999 and December 2010. Eighty-three patients (16.4%) were identified who had required 92 ICU admissions. The indication for ICU admission was hemodynamic instability in 47.0% of patients and respiratory impairment in 42.2%. The underlying pathology was most commonly infection (77.1%). Vasopressors were required in 67.5% of admissions, mechanical ventilation in 60.2% and hemodialysis in 15.7%. Rates of survival to hospital discharge and 12 months were 59.0% and 41.3%, respectively. Mechanical ventilation use and higher fibrinogen were independently associated with mortality prior to hospital discharge, and mechanical ventilation use and AML cytogenetic risk group were predictive of mortality within 12 months of ICU admission. By providing a more accurate estimation of a patient's chance of recovery, such prognostic factors may contribute to decision-making about the appropriateness of admission to the ICU or continuation of intensive life-sustaining measures.