Did an acute medical assessment unit improve the initial assessment and treatment of community acquired pneumonia: a retrospective audit

MAPUs, also known as Acute Medical Assessment Units (AMAUs), are advocated as a means to achieving more timely and appropriate assessment and treatment of acutely unwell medical patients.1 A large number of AMAUs have opened over the last 15 years. Limited controlled and observational studies suggest reductions in overall length of stay and mortality without increases in readmission rates.2 Assessments of the impact of AMAUs on the quality and timeliness of the assessment and treatment of common medical conditions are scant.Community-acquired pneumonia (CAP) is a common medical condition whose treatment is supported by evidenced based guidelines.3 These include recommendations for a door-to-antibiotic treatment time for the majority of patients with confirmed CAP of less than 4 hours. Compliance with CAP guidelines is used as a means of assessing quality of clinical care.4,5This study sought to retrospectively audit the impact of the opening of a MAPU on the treatment of CAP at Wellington Hospital, with respect to door-to-needle times and other clinical quality indicators suggested by evidence based guidelines.The MAPU at Wellington Hospital was opened in November 2009, assessing and admitting direct referrals from GPs and patients presenting to and initially assessed by the emergency department (ED). The MAPU was modelled closely on the objectives and organisational structure of the IMSANZ Standards6 with daily consultant rounds in a purpose designed 18 bed unit (also including a further 6 high dependency beds) close to the ED, with the objective of admitting all general medical patients with an expected length of stay less than 36 hours.Methods A retrospective audit was undertaken of all patients discharged from any hospital service with a primary diagnosis of CAP from January - March 2009 and from January - March 2010. These two cohorts straddle the opening of the MAPU, are matched for season (summer), and exclude the impact of the H1N1 pandemic commencing in April 2009. A nearby secondary hospital, Kenepuru Hospital, accepted GP referred admissions direct to its inpatient medical service until November 2009. These were discontinued with the opening of the MAPU at Wellington Hospital. Patients from 2009 admitted to Kenepuru have been included in the analysis as these patients would have, in 2010, been referred to either MAPU or the Emergency Department. Patients were identified by electronically selecting all adult discharges with a principal diagnosis coded as pneumonia or one of its subsets (ICD 10 code J189). Cases seen and discharged from the Emergency Department were not captured. A total of 217 patients were identified, of which 62 were excluded as outside study criteria as follows: Not pneumonia on presentation: patients presenting with an unclear diagnosis or admitted for another indication 15 Patients with possible respiratory tract infection, no X-ray change and complex comorbidity 12 Neutropenic sepsis: Oncology patients with known risk of neutropenia, presenting febrile and treated according to a neutropenic sepsis protocol 3 Inter-hospital transfers: admitted at another hospital and transferred, typically either for ICU care or decortication of empyema 13 Coding Error: Primary diagnosis of pneumonia not supported by consultant or radiologist 8 Elective day case bronchoscopy, for persisting consolidation, coded as pneumonia 3 Notes incomplete 3 Other reasons 5 Total 62 "Other reasons" included patients incorrectly coded to general medicine and without pneumonia (e.g. oncology and trauma patients with other lung pathology) and patients recorded as admitted who were only seen as ED patients. 155 cases remained for formal review of hospital case records, collating information from paper notes and electronic records (Emergency Department, Laboratory, Radiology, and Patient Management systems). All ED and Medical histories were reviewed by the author. Pneumonia is a diagnosis often requiring clinical judgement. While formal definitions of pneumonia require focal radiological change, cases were included if the consultant on the post-take round agreed with the admitting diagnosis of probable pneumonia, even if the subsequent radiologist report did not (14% of cases). Data collected on each patient included: basic demographic data presentation point and time, and referral source time of medical reviews and by doctors of which service. The ED patient tracking system automatically logs the time first seen by a doctor. The paper based system in MAPU relied upon doctors recording the time the patient was seen. vitals over the first 4 hours content of initial clinical assessment, consultant ward round diagnosis, and resuscitation discussions during the admission investigations, including blood tests, microbiology, x-rays time, location and class of initial antibiotics discharge time and destination Statistical analysis was conducted using Epi Info software. Results Demographics—73 cases were audited in 2009 and 82 in 2010. In 2010, the mean age of MAPU patients was lower and these patients had fewer comorbidities and lower severity illness compared to patients presenting to ED. There were no significant variations in ethnicity between arrival points. Demographic data and disease severity data are presented in Table 1. Table 1. Demographics of audited cases 2009 ED & Kenepuru 2010 All Cases P value (ED ‘10 vs MAPU) ED MAPU Number 73 55 27 155 Mean age 65 65 54 64 0.04 % Male 60% 49% 66% 57% 0.13 Other chronic illness1 -Multiple systems 58% 62% 37% 55% 0.12 -Single system 24% 17% 26% 22% -None 18% 22% 37% 23% % Arriving by ambulance 58% 74% 33% 60% <0.01 Average CURB652 1.6 1.7 0.9 1.5 <0.01 1Comorbidities requiring on-going treatment, but excluding primary prevention (typically hypertension). 2CURB65 is a prospectively validated severity score giving 1 point for each of age > 65, respiratory rate >= 30, Urea > 7.0, hypotension (SBP < 90 or DBP <= 60), and confusion. CURB65 scores were only recorded on 15% of admissions. A retrospective CURB65 score was therefore calculated for all patients. Where Urea was not ordered, a point was given if the patient had an acute rise in creatinine or was clinically assessed as dehydrated, although this is an imperfect substitute. The presence or absence of confusion was often undocumented. This calculated score is therefore likely to understate average CURB65 scores. Time to assessment and treatment—Patients’ progress through the process of assessment is shown in Table 2. Times are stated in minutes, and are median times given the long tails occurring in both ED and MAPU patients. P values compare 2010 patients in ED compared to MAPU. 33% of MAPU admissions did not record the time of first assessment by the doctor. This potentially biases the average MAPU time to first medical review. Table 2. Minutes to assessment and treatment Variables ED ‘09 Kenepuru ‘09 ED ‘10 MAPU ‘10 P value (ED ‘10 vs MAPU) Arrival to first doctor 39 57 42 86 0.00 Arrival to X-ray ordered 61 63 65 84 0.54 From X-ray ordered to X-ray taken 33 52 28 83 <0.01 Arrival to ABs 179 233 155 215 0.36 % with ABs within 4 hours 70% 58% 67% 56% 0.36 Content of clinical assessment—The checklist in Table 3 was used to evaluate the admitting medical team’s assessment, largely drawing from British Thoracic Society (BTS) Guidelines3. The rationale for a MAPU is not only more timely assessment by appropriate specialists, but more relevant and comprehensive assessment. Differences between 2009 and 2010 were therefore of interest. Table 3. Content of clinical assessment for all patients 2009 vs 2010 Variables