Organisation and technology as factors of success in A&E

Professor Wilfried von Eiff

The NOPAC study (Emergency Admission and Point of Care Technologies) carried out by the Centre for Hospital Management at the University of Münster, examines to what extent the prompt and plannable availability of selected laboratory parameters (D-Dimer; TSH; NT-probBNP; Troponin I/T) can reduce pressure on staff, medical equipment, functional diagnostics, intensive care, and so on, so that the cost of a patient’s care process can be reduced.

The NOPAC study has found that the laboratory-diagnostic turnaround time is a significant driver of the overall emergency care process for medical quality, patient outcome and overall cost of care of an emergency patient.

Needs-driven and economic care of emergency patients is linked to a small number of key success factors as follows:

1. Process integration and networking

The central A&E department is the hub between the emergency medics who initially provide treatment and further treatment provided on the ward. This means that service providers within the emergency care chain should be coordinated with one another to ensure that the patient receives appropriate, high level medical care without delay at each point in time.

Therefore, an important success factor for the A&E department is professional, intensive and prompt communication with the emergency doctors in pre-clinical care. The more qualified the ambulance team is to deal with stroke, heart attack, or trauma patients, the earlier and more precisely the relevant data can be transmitted to the A&E department before a patient’s arrival in hospital.

Experiences from the AMI network of the Kerckhoff-Klinik in Bad Nauheim, Germany, show that the period between the first medical contact after a myocardial infarction and the opening of the vessel in the catheter laboratory is (contact-to-balloon-time) under three hours and the door-to-balloon-time under 90 minutes if emergency doctors take a patient’s blood when still in the ambulance, evaluate the 12 channel ECG and report the patient’s imminent arrival to the catheter laboratory via the ‘red telephone’.

2. Admission to short stay ward and chest pain unit

This type of ward ensures that the following problems are avoided in the treatment process:

• Admission to the wrong type of ward and department due to an unclear diagnosis as a result of time pressure (for instance, 25% of angina pectoris patients with suspected acute coronary syndrome have an extra cardiac diagnosis)
• Unnecessary secondary transport within the hospital
• Time delay in diagnosis and treatment due to non-availability of technology (MRI, CT etc.) or of colleagues providing a second opinion
• Lack of capacity buffers for short-term monitoring, therefore blocking of examination and treatment spaces or premature transfer to a ward

3. POCT Technologies

Looking at the generic process of emergency care (image 1), it becomes clear that the quality (reliability of measurements) and the length (turnaround time) of the part-process laboratory diagnostics are critical success factors for clinical quality, patient satisfaction and the costs of clinical emergency care and aftercare.

Laboratory services based on POCT technologies increase the patient safety, speed up diagnosis and treatment processes and reduce contingency and process costs; this particularly applies if, through the fast availability of laboratory parameters, functional diagnostics can either be bypassed or reduced in a process enhancing manner, or if it can be used case-specifically for an earlier clarification of the diagnosis.

POCT facilitates the fastest possible availability of, particularly, the decision-relevant parameters Troponin I/T, BNP/NT-proBNP, D-Dimer and Lactate, with Troponin I/T and Lactate being the most significant predictors of increased risk of morbidity.

• BNP/NT-proBNP levels are available after 35 minutes and facilitate early clarification of pulmonary or cardiac causes respectively and make it possible to detect heart failure. Classic early functional diagnostics (X-ray) clearly lags behind.
• BNP/NT-proBNP levels are available after 20 minutes via POCT and facilitate early detection of cardiac decompensation as well as CHE differentiation in case of dyspnoea and pulmonary embolism respectively.
• This POCT risk evaluation (BNP/NT-proBNP) replaces the more time-consuming echocardiography (ideal case: 10 minutes; reality: 2-3 hours) and supports the decision for early discharge into out-patient care.
• TSH is a further time-sensitive factor, as the TSH levels decide at which point which imaging procedure can be used. TSH levels are normally only available after 60-90 minutes via central laboratory diagnostics. Therefore it would be desirable that the TSH level is qualified and available within 20 minutes via POCT technology.
• Creatinine levels for clarification of kidney function and determination of contrast media tolerance can be available via POCT after 2 minutes.

If the D-Dimer levels are available after 20 minutes for a patient with leg pain (suspected thrombosis) an immediate decision can be taken, together with a WELLS score examination, whether the patient can be discharged or whether they should be classed as high risk; in this case a Doppler examination is carried out, which means that functional diagnostics can be bypassed. The resulting gain in time of about 1-2 hours increases patient satisfaction and avoids a crowding effect of patients who have to be monitored in A&E.

With the care of acute coronary syndrome (non-STEMI) patients, the availability of Troponin I levels after 18-20 minutes (Troponin T levels after 12 minutes) is of significant clinical and economic relevance. On the one hand, the risk of undetected heart attacks (EVA syndrome) reduces through the use of highly sensitive troponins; on the other, the total length of stay in the A&E department per ACS patient reduces from 05/05:30 hrs (central laboratory) to 04/04:30 hours (POCT diagnostics).

Results of this POC solution:

• Significantly shorter length of stay of ACS patients (reduction of 40-60 minutes)
• Avoids blocking of examination and treatment beds
• Avoidance of premature transfer to the ‘wrong’ ward (such as intensive care ward for instance with daily costs of €1,000 - €1,200) because of lack of capacity in A&E
• Quality, targeted follow-on treatment
• Avoidance of crowding effects

The NAPOC study also shows that POCT technologies in A&E also facilitate a controlled and plannable diagnostic process from the A&E doctors’ viewpoint: The variances in turnaround time (from taking blood to availability of results) for Troponin T are between 40-160 minutes with the central laboratory solution and between 13-34 minutes in the case of a POCT-supported organisation (technical setting: AQT90 Flex).

Highly sensitive POCT diagnostics also supports in areas where not all patients in need of treatment can be identified with other diagnostic procedures: The rate of heart attacks not detected by the 12 channel ECG is between 10-20%.

The NAPOC study also makes clear that consistent use of POCT in emergency medicine alone is not sufficient for the utilisation of all rationalisation potentials. If the work of Renaud et al. is analysed as to the confounding factors, it becomes obvious that POCT advantages can be (over-) compensated by other structural or organisational disadvantages. The POCT solution is faster by an average of 71 minutes compared to the central laboratory solution: The fact that the length of stay in A&E is almost identical for both technology settings can possibly be traced back to the fact that both a short stay ward and a chest pain unit were integrated in the central laboratory setting at the same time.

Finally, we can assume that the demand for capacity in A&E could be reduced by 25 – 28% through POCT in combination with other structure and process optimising measures.

The question as to the economic advisability of an investment in POCT technology (in the present setting around €28,000 for an AQT90 Flex) is not limited to a pure cost comparison per sample sent to the central laboratory. The key issue is that this investment decision is also assured by inclusion of the criteria ‘quality and promptness of diagnosis’, ‘process follow-on costs’ and ‘risks for the patient’ (see risk-weighted process cost analysis – RPA – in image 2).

Summary

Quality and efficiency of emergency care directly depends on prompt diagnostic laboratory medicine: the importance and proportion of laboratory medicine within the overall diagnostic process and its results is up to 70%. To reduce the turnaround time (from samples requesting to the availability of sample results in the location where treatment decisions are made) time-and treatment critical parameters can be better determined with POCT equipment. The effects:

• a shorter wait for the patient
• earliest possible start of treatment
• therapeutic prognosis improves
• pressure on monitoring capacity in A&E is reduced; and
• qualified discharge diagnosis and qualified treatment decisions respectively reduce pressure on intensive care medicine and intermediate care.
• For the A&E department, a POCT is a self-determined process for the ascertainment of diagnosis-relevant and time-critical laboratory parameters (such as Troponin I/T; CK-MB; D-Dimer). Patient risks, patient satisfaction, medical results and process costs are all positively impacted by POCT in the A&E department.

• Further critical factors of success in clinical emergency care are:

• process integration and networking of preclinical, clinical and post-acute emergency care, and the
• setting up of short stay wards and chest pain units.
 

20.10.2011

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