Prospective assessment of patients' knowledge and informational needs and of surgeon-to-patient information transfer before and after knee or hip arthroplasty

BACKGROUND

Patients are playing an increasingly large role in their own management and must therefore receive clear, complete, and comprehensible information. In the field of hip and knee arthroplasty, little is known about the level of patient knowledge and effectiveness of surgeon-to-patient information transfer. We therefore designed a prospective observational study with the objective of assessing four factors: patient knowledge during management, quality of information transfer, informational needs, and factors associated with the level of knowledge.

HYPOTHESIS

The level of patient knowledge changes during the management process.

PATIENTS AND METHODS

A prospective single-centre study was conducted between January 2014 and March 2015 during the outpatient visits and inpatient stays of 63 patients who underwent arthroplasty of the hip (n=36) or knee (n=27). A single observer attended all patient visits and recorded the information provided by the surgeon. Each patient completed a self-questionnaire after the outpatient visit (T1), at admission (T2), and at discharge after surgery (T3). Semi-quantitative scores were used to assess knowledge and informational needs. The effectiveness of information transfer was evaluated by comparing the information provided by the surgeon to the replies made by the patients.

RESULTS

The mean overall knowledge score (on a 0-42 scale) increased from 17.22±6.33 at T1 to 19.44±6.89 at T3 (P=0.0028). In contrast, knowledge about complications was better at T1 than at T3 (2.67±1.98 vs. 2.19±1.91; P<0.05). Agreement between information given by the surgeon and replies made by patients varied across items from 23% to 100%. The mean informational needs score (on a scale from 0 to 21) ranged from 3.67 to 4.83 and was higher at T3 than at T2 (4.83±3.77 vs. 3.67±4.86; P=0.03). The proportion of patients who wanted written information was higher at T3. Most patients sought information before the outpatient visit. At each step of the management process, the main areas about which the patients wanted information were the surgical procedure, the rehabilitation programme, and the prosthesis. Several socio-demographic or management-related factors influenced the level of knowledge. Thus, older age and lower educational attainment were associated with lower knowledge scores, whereas previous lower-limb orthopaedic surgery and amount of information provided by the surgeon were associated with higher knowledge scores. Knowledge scores were not associated with being employed vs. retired, gender, replacement of a hip vs. a knee, the surgeon, or being accompanied by another person.

DISCUSSION

Our study is original in that we assessed changes in patient knowledge during the management process for hip or knee arthroplasty. The level of patient knowledge was fairly low and varied considerably across individuals and time points in the management process. These data highlight the importance of providing patients with information throughout their management and particularly at discharge, when the desire for information seems greatest.

LEVEL OF EVIDENCE

IV, prospective observational study with no control group.

Evaluation of childhood exposure to di(2-ethylhexyl) phthalate from perfusion kits during long-term parenteral nutrition

Leachability of the plasticizer di(2-ethylhexyl) phthalate (DEHP) from administration sets into intravenous parenteral emulsions containing fat was investigated. DEHP is added to polyvinyl chloride (PVC) to impart flexibility. However, DEHP is a lipid-soluble suspected carcinogen that is hepatotoxic and teratogenic in rodents, and has been shown to leach from PVC products containing lipophilic mixtures. Consequently, total parenteral nutrition (TPN) mixtures containing fat emulsions should be stored in ethylvinyl acetate (EVA) bags rather than PVC packs. However, while TPN bags are made of EVA, they contain PVC-DEHP residues and the lines used between TPN bags and venous catheters are made of PVC-DEHP. The present study quantified the amount of DEHP leached from bags and tubing that could potentially contaminate patients during home TPN. Four types of emulsions containing fat were studied. Levels of DEHP in the bag and at the outlet tubing were measured by high-performance liquid chromatography (HPLC). This was measured during simulated TPN at different times after starting perfusion, 1 day after reconstitution of solutions in the bags, and 1 week later after storage at 4 degrees C. Detectable and stable amounts of DEHP were found to leach from bags (0.2 +/- 0.008 mg to 0.7 +/- 0.02 mg) and DEHP content increased in the outlet tubing (0.8 +/- 0.09 mg to 2 +/- 0.07 mg) during simulated infusions. The same phenomenon was observed after 1 week of storage at 4 degrees C. DEHP extraction by TPN depends on the lipid content of each TPN preparation and the flow rate. These results suggest that children treated with prolonged TPN are regularly exposed to significant amounts of DEHP.

High-performance liquid chromatographic method for the determination of di(2-ethylhexyl) phthalate in total parenteral nutrition and in plasma

A simple, rapid and sensitive reversed-phase high-performance liquid chromatographic method with UV detection was developed for the quantification of di(2-ethylhexyl) phthalate (DEHP) in parenteral nutrition admixtures containing fat emulsion and in plasma samples of children daily treated by total parenteral nutrition. The analyte and the internal standard, di-n-heptyl phthalate, were extracted twice using hexane and the organic layer separated and dried under nitrogen. The residues were reconstituted with acetonitrile and 20 microl was injected into a Waters Spherisorb C18 column, the UV detector was set at 202 nm. The mobile phase was acetonitrile-aqueous buffer (triethylamine 0.08% adjusted to pH 2.8 with 1 M phosphoric acid) mixture (88:12, v/v) and it was pumped at 1 ml/min. Average recoveries were 97% or greater. This method was successfully used to investigate the amounts of DEHP which can leach from bags and tubing into fat emulsion and which could contaminate children under long-term parenteral nutrition. On the other hand, the circulating DEHP concentrations were estimated in four children under regular long-term parenteral nutrition.