JAC Advance Access originally published online on June 23, 2009
Journal of Antimicrobial Chemotherapy 2009 64(3):630-634; doi:10.1093/jac/dkp212
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Original research |
Establishment of an outpatient and home parenteral antimicrobial therapy service at a London teaching hospital: a case series
1 Infectious Diseases, Imperial College Healthcare NHS Trust, St Mary's Hospital, London W2 1NY, UK 2 Microbiology, Imperial College Healthcare NHS Trust, St Mary's Hospital, London W2 1NY, UK 3 Pharmacy Department, Imperial College Healthcare NHS Trust, St Mary's Hospital, London W2 1NY, UK
* Corresponding author. Tel: +44-207-886-1203; Fax: +44-207-886-2083; E-mail: hayley.wickens{at}imperial.ac.uk
Received 18 February 2009; returned 24 March 2009; revised 20 May 2009; accepted 26 May 2009
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Abstract |
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Background: Outpatient and home parenteral antimicrobial therapy (OHPAT) is becoming increasingly commonplace in the UK, enabling those patients who would previously have been obliged to remain in hospital for intravenous treatment to be managed as outpatients or in their own homes. The OHPAT service at St Mary's Hospital, London, was established in 2004. This paper describes the types of infection, antimicrobial management and outcomes of patients referred to the service in the 3.5 years since its inception.
Patients and methods: All inpatients were eligible for OHPAT, provided that they had a serious infection requiring parenteral therapy, were well enough to leave hospital and fulfilled other criteria. We initially used an outpatient clinic model, but as the service developed, treatment was often delivered in patients' homes, with the OHPAT team providing training and assessment of primary care staff.
Results: Four hundred and sixty-seven patients were referred to the service between September 2004 and April 2008. Of these, 273 received 303 courses of OHPAT, 48 were discharged on oral therapy and 3 patients declined outpatient therapy; the remaining 143 patients were deemed unsuitable for inclusion, most commonly because the patient was too unwell for discharge (28.7%) or their social situation was inappropriate (14.7%). Causative organisms were identified in two-thirds of cases, with methicillin-resistant Staphylococcus aureus implicated in one-third of these. Mean treatment length was 24 days (range 1–165 days), with 7394 inpatient bed-days saved. Less than 5% of patients were readmitted within 28 days with infection- or drug-related problems. There were no cases of Clostridium difficile-associated diarrhoea during or after outpatient treatment, despite extensive use of cephalosporins and other broad-spectrum agents. Patients found the service highly satisfactory and felt that it had improved their quality of life during the treatment period.
Conclusions: The introduction of the OHPAT service at St Mary's Hospital has proved to be of benefit to patients and hospital efficiency alike.
Keywords: OPAT , home intravenous antibiotic therapy , antimicrobial management , antimicrobial therapy , antibiotics , bacterial infections , antibiotic pharmacist
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Introduction |
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Outpatient and home parenteral antibiotic therapy (OHPAT) programmes are well recognized and accepted modes of providing healthcare in the community worldwide, but the UK has been relatively slow to adopt this practice.1–6 Such schemes permit patients who would otherwise remain in hospital solely to receive intravenous antimicrobials to be discharged, provided that they are otherwise well. Patients thus discharged may then either return to a hospital clinic or community nurse treatment facility to receive their intravenous medication, or can be treated in their own home by community-based nurses. Where a patient or carer is willing, they may be trained to self-administer intravenous antibiotics, with intermittent clinical reviews to ensure recovery is progressing.
With an emphasis being placed by the UK Department of Health upon reducing lengths of inpatient stay and a shift towards management of care by specialists in the community,7 increasing numbers of UK hospitals are now establishing OHPAT services. Shorter hospital stays are associated with a reduced risk of acquiring a healthcare-associated infection8,9 and treatment in the ambulatory setting can reduce costs of care in certain infections by up to 85%.10,11 The acquisition costs of some antibiotics commonly used in the OHPAT setting are higher than the alternatives used for inpatient treatment;12 however, the indirect costs of intravenous therapy in the community can be considerably lower than treatment in the acute hospital setting,8 which makes OHPAT attractive as a means of reducing costs associated with long-term antimicrobial therapy.
The OHPAT team at St Mary's NHS Trust (now incorporated within the Imperial College Healthcare NHS Trust) was established in 2004, and initially comprised one Clinical Specialist Nurse (CSN), consultants in Infectious Diseases (ID) and Clinical Microbiology, and an antimicrobial specialist pharmacist; a second CSN was appointed in July 2006. The OHPAT service was publicized extensively throughout the Trust, and clinical teams and ward pharmacists were encouraged to refer patients to the service via a dedicated fax and pager system.
There were 467 patients referred to the OHPAT service between September 2004 and April 2008. This paper describes the nature of the infections treated, the organisms isolated, antimicrobials used and outcomes for these patients.
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Patients and methods |
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Inclusion criteria
All inpatients were eligible for inclusion in the scheme, provided that they fulfilled certain criteria: serious infection requiring parenteral therapy; patient deemed well enough to leave hospital by the clinical team; relevant bacteriology compatible with outpatient treatment, ideally using a once-daily antimicrobial; patient able and committed to daily/thrice-weekly clinic attendance for treatment and assessment, or domestic situation amenable for home-treatment and appropriate community nursing support available; no indication of potential intravenous drug abuse by patient; and patient consent obtained.
Initially, treatment was based on the outpatient clinic model, but the enthusiasm of local community nursing services enabled the roll-out of services into the primary care setting in December 2004. The OHPAT team provided training and assessment of primary care staff, and developed shared care guidelines to ensure the safe administration of the intravenous drugs in the community, as reviewed elsewhere.1,13,14 The OHPAT team also produced specific paperwork, including a designated set of patient notes, drug prescription and administration records, and medicines information documents for staff and patients, as recommended by Tice.15
The OHPAT service was publicized extensively throughout the Trust and any member of clinical staff could refer a patient to the OHPAT service. Once a referral had been received, the patient was assessed for suitability by the OHPAT CSN, who then brought appropriate cases to the twice-weekly multidisciplinary team meeting for discussion. At this meeting, the OHPAT team recommended a course of therapy, and the CSN subsequently made arrangements for drug supply and clinic appointments, and, where necessary, inserted a peripherally inserted central catheter. Antimicrobials were prescribed by the referring medical team under advice from the OHPAT team. To further develop the service, the CSNs are currently undergoing prescribing training to streamline this part of the process. All drugs, diluents and flushes were supplied by the hospital and charged to the referring team. A minimum of the first dose of each course was administered in the hospital before discharge. General practitioners were informed of their patients’ involvement in the scheme by letter from the OHPAT team upon discharge from hospital.
It is important to note that clinical responsibility for patients remained with the referring team throughout their treatment, even when that treatment was delivered in the home setting. The OHPAT team, under the auspices of the ID/Microbiology team, dealt with any immediate problems arising during outpatient treatment. Outpatients were seen daily or three times weekly in the OHPAT clinic, and those patients treated at home returned to the clinic for weekly assessment and blood tests. Once outpatient treatment was initiated, patients were able to contact an OHPAT CSN 24 h a day, 7 days a week via a pager, with back-up from the clinical microbiologist on call. If a patient required readmission, clinical support was available from the medical registrar on call and responsibility for day-to-day care of the patient reverted to the original referring team.
All patients using the OHPAT service in its first year were given a patient satisfaction survey questionnaire upon discharge from the service, along with a stamped addressed envelope to expedite return; in subsequent years, every second patient was given a questionnaire.
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Results |
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Number of patients referred and accepted
Of 467 patients referred to the OHPAT service between September 2004 and April 2008, 273 were accepted for parenteral treatment, an additional 48 were switched to oral therapy for discharge and 3 patients declined outpatient therapy. Of the remaining 143 patients not accepted for OHPAT, over one-quarter (28.7%) were too unwell to be discharged or had additional medical problems preventing discharge; other reasons are listed in Table 1.
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Number of treatment courses received and setting
The 273 patients accepted by the OHPAT service received 303 courses of parenteral antimicrobial therapy: the majority (95%) received a single course of antimicrobials.
The mean age of patients was 60 years (range 20–93 years) and 54% were male. The principal sites of infection in each patient are listed in Table 2. A small number of patients (<1%) had additional sites of infection (e.g. osteomyelitis and urinary tract infection; data not shown); appropriate therapy was chosen to cover both infection sites.
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Of the 303 courses given, 56 (18.5%) were administered in the OHPAT clinic, 7 (2.3%) were delivered by private healthcare companies in patients' homes, 6 (2.0%) were self-administered or given by a carer at home and the remainder were predominantly administered by community nurses from 15 Primary Care Trusts, with occasional doses given in the OHPAT clinic.
Causative organisms, agents used and duration of treatment
For patients accepted by the OHPAT team, causative organisms were identified in 202/303 (66.7%) cases and are listed in Table 3. In 37/303 (12.2%) cases no specimens were sent and in a further 64 (21.1%) cases specimens were sent but no organism was isolated.
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Where a causative organism was identified, the most common was methicillin-resistant Staphylococcus aureus (MRSA), either alone (52/202, 25.7% of patients with an identified organism) or as part of a mixed infection (14/202, 6.9% of patients with an identified organism). Methicillin-susceptible S. aureus (MSSA) was the second most commonly isolated organism, either alone (30/202, 14.9%) or as part of a mixed infection (11/202, 5.4%). Coagulase-negative Staphylococcus spp. were considered to be the sole infecting organism in 18 (8.9%) of 202 infections where an organism was isolated and Pseudomonas spp. in 10/202 (5.0%).
Twenty different parenteral antimicrobial agents were used, alone or in combination, with or without the addition of oral agents as appropriate. Where agents were used that require blood monitoring (e.g. gentamicin, vancomycin and teicoplanin), blood tests were taken by the OHPAT CSN in the clinic at appropriate intervals, including for patients otherwise managed at home by community nurses. Drug dosage was adjusted when necessary, in consultation with the OHPAT team. Approximately 50% of treatment courses were administered as intravenous bolus; the remainder were given as infusions. Where twice- or thrice-daily regimens were used, a combination of OHPAT clinic visits, home visits from community nurses and self-administration was employed.
The mean length of treatment was 24 days (range 1–165 days), with a total of 7394 inpatient bed-days saved. This figure was calculated from the number of days of parenteral therapy scheduled to be received by OHPAT patients after discharge from hospital.
Readmissions within 28 days and adverse events
There were 23/303 (7.6%) OHPAT courses that were followed by a readmission during therapy or within the 28 days following completion. Of these, 10 readmissions (3.3% of total number of courses) were due to problems unrelated to the original diagnosis for which OHPAT was prescribed and 13 (4.3%) were related to the original diagnosis or drug prescription. In three patients, OHPAT had been initiated as conservative therapy and the patient was readmitted for surgery owing to treatment failure (prosthetic knee joint removal, partial foot amputation and renal infection in patient unsuitable for surgery), two readmissions were related to line problems during therapy (thrombus formation and infection) and two patients suffered adverse drug effects resulting in readmission (vomiting, dizziness related to ceftriaxone and neurological effects related to gentamicin). Three readmissions were judged to be the result of treatment failure at the end of the originally prescribed course: one associated with secondary infection of previously undisclosed prosthetic material; one treatment failure of an infected nephrostomy wound; and one treatment failure in a patient with bronchiectasis who was admitted after 13 days of OHPAT with increasing shortness of breath (no organism was isolated from this patient). One patient was readmitted with superinfection of leg ulcers associated with an inappropriate dressing regimen, and two patients worsened clinically at home, but continued with their planned OHPAT regimen as inpatients and infection resolved successfully.
In addition, vascular access was lost in two patients, resulting in OHPAT being discontinued 3 and 4 days before the planned end of therapy; in neither case were there any adverse effects and the patients were successfully discharged. In the remaining 278 episodes, the patients were successfully treated as per plan and discharged from the OHPAT service at the end of their therapy.
Three patients suffered an adverse drug effect that was not sufficiently serious to warrant discontinuation of treatment. There were no incidences of Clostridium difficile-associated diarrhoea (CDAD) in the 28 days following discharge and we are not aware of any cases arising subsequently in this patient cohort.
Patient opinions of the OHPAT service
In the first year of the service, 59 patient satisfaction survey questionnaires were distributed and 33 (55.9%) returned. Subsequently, 120 further questionnaires were given to OHPAT patients and 51 (42.5%) returned. These results are therefore based on 84 returned forms: 81/84 respondents felt that the service met their expectations and the same number felt that they would be happy to receive this form of treatment again should the situation arise; 84/84 respondents were happy with the support they received from the OHPAT team during their treatment; 83/84 respondents felt that they were seen promptly in the clinic; and 80/84 respondents felt that their quality of life during the period of infection had been improved by outpatient management. Two patients who felt that their quality of life had not been improved had suffered an adverse drug event. Seventy out of 84 respondents felt that the service could not be improved.
The most frequent comments from the 14/84 patients who felt improvements could be made involved problems with patient transport (6/14). Two patients felt that communication between consultants, other staff and patients could be improved, three patients felt that they had waited too long and one patient suggested that referrals could be made directly to the service from their general practitioner.
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Discussion |
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The introduction of the OHPAT service at St Mary's Hospital has proved to be of considerable benefit to patients and hospital efficiency alike. Over the initial 32 month period, 273 patients received parenteral antimicrobials either as outpatients or at home, releasing over 7000 bed-days for reallocation. An additional 47 patients referred to the OHPAT team were discharged on oral antimicrobials, thus avoiding the need for parenteral therapy altogether. Infection resolution was achieved after the first round of outpatient parenteral therapy in >95% of cases, readmission rates at 28 days were low and few adverse events were recorded.
MRSA was the most commonly isolated causative organism, seen in one-third of the treatment episodes where an organism had been identified. This represented 1798 days of outpatient parenteral treatment for patients who were not suitable for treatment with oral alternatives such as linezolid. The facility to treat these patients with intravenous agents whilst discharging them to the community removed them as a possible source of MRSA transmission within the hospital and, in many cases, resulted in the redeployment of scarce isolation facilities (data not shown).
No cases of CDAD were recorded in our patient cohort during or in the 28 days after finishing treatment. This may, in part, reflect a reduced risk of C. difficile exposure when patients are treated outside the hospital setting.
As has been noted elsewhere,12 the acquisition costs of the antimicrobials used in OHPAT services can exceed those of the inpatient alternatives. For example, the drug acquisition costs of an average course of ceftriaxone were 
£400, double that for an inpatient alternative such as intravenous flucloxacillin and benzylpenicillin. It could be argued that savings on hotel costs per episode and decreased risk of hospital-acquired infection outweigh this.
In developing the service, unforeseen complications were few. However, due to the location of the hospital in central London, patients sometimes experienced traffic or public transport problems during their journeys to the clinic, occasionally arriving >1 h late for their appointments. This had implications for timing of regular doses and acceptability of the service to patients, and necessitated a degree of flexibility from the OHPAT CSN when organizing their workload. Anecdotally, similar issues affected community nurses using public transport or driving to visit patients at home in the London boroughs. It might therefore be argued that treatment is more convenient for the inpatient as it is delivered at the bedside; however, the results from our satisfaction survey suggested that patients were motivated to receive outpatient therapy, despite sporadic logistical problems. In addition, some patients are not suitable for OHPAT for operational or clinical reasons and the number of inappropriate referrals was relatively high when we launched our service, with approximately one-quarter of inappropriately referred patients being too ill for discharge. As clinician familiarity with the service has increased and following educational initiatives, the number of inappropriate referrals has declined.
It was considered essential that the referring team retain overall clinical responsibility for the patient and resumed care should the patient require readmission whilst receiving OHPAT. This, combined with regular patient attendance at the CSN OHPAT clinic, helped to ensure that any unforeseen clinical problems could be dealt with promptly. We felt that a comprehensive assessment and discharge plan was fundamental to the success of the OHPAT care pathway, as was close collaboration with the community nursing teams where these were involved in delivery of outpatient therapy.
The multidisciplinary collaboration between the OHPAT CSN, Microbiology and ID clinicians, and Pharmacy worked well, despite the absence of a dedicated ID ward at our hospital, the latter being a central feature of OHPAT schemes described elsewhere.3,16–18 We would suggest that this model could be rolled out to other Trusts that may lack a dedicated ID ward.
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Funding |
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No specific funding was received for this study; data were generated as part of the routine work of the organization.
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Transparency declarations |
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TopAbstractIntroductionPatients and methodsResultsDiscussionFundingTransparency declarationsReferences |
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H. J. W. has provided consultancy or received funds to attend/speak at meetings from Ashley Communications, AstraZeneca, Chiron, Conventus, GSK, Janssen-Cilag, Johnson & Johnson, Pfizer, Sanofi-Aventis, Ted Butler and Associates, Westaway Gillis and Wyeth. J. H. has received funds to attend/speak at meetings from Vygon (UK) Ltd. A. P. J. and J. M.: none to declare.
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References |
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