Research setting

3.3.1 Heart of England NHS Foundation Trust

The research that forms the basis of this thesis was undertaken at Heart of England NHS Foundation Trust (HEFT) between October 2011 and January 2015. HEFT is a large NHS trust with over 1400 in-patient beds across three hospitals: Birmingham Heartlands Hospital (BHH); Good Hope Hospital (GHH); and Solihull Hospital (SH).

BHH is a large tertiary teaching hospital with 703 beds. The hospital provides a broad range of medical services, as well as elective and emergency surgical services. The hospital hosts tertiary-level care services for respiratory medicine, haematology, thoracic surgery, vascular surgery, and infectious diseases. The emergency department saw 112,171 patients in 2013. The critical care unit has 19 beds.

GHH is a district general hospital with 480 beds. The hospital provides general medical and surgical services, including emergency general surgery. The emergency

department saw 78,713 patients in 2013. The critical care unit has 10 beds.

SH is a district general hospital with 248 beds. The hospital provides general medical and elective surgical services. The Emergency Department saw 44,530 patients in 2013. The acute medical unit accepts adult non-surgical emergency ambulance alerts, such as out-of-hospital cardiac arrest patients. The hospital has no dedicated critical care facilities. Patients requiring intensive care are transferred to other hospitals.

3.3.2 Hospital adult emergency team

Role and composition of the hospital adult emergency team

At each hospital site, an emergency team is tasked with responding to cardiac arrests and other medical emergencies on the hospital grounds. The core team operates both day and night and is composed of two medical doctors, an intensive care unit doctor, a critical care outreach nurse, a senior nurse, and a porter. They attend all emergency calls. Specialist cardiac nurses, resuscitation officers, and other key personnel form part of a non-core team and may attend in addition to the core team. All clinical team members hold either Advanced Life Support or Immediate Life Support certification. The team leader is usually the most senior doctor but may be any Advanced Life Support provider. Team composition is broadly reflective of practice in other local hospitals and adheres to Resuscitation Council (UK) guidelines.27,183 _{The emergency}

team is provided in addition to standard treatment escalation policies, which are guided by an early warning score system.27,34

Activation of the hospital adult emergency team

Each emergency team member carries a pager. Core team member pagers must be carried by an appropriate clinician at all times. Pagers are tested on a daily basis.

To summon the emergency team, hospital staff call a dedicated emergency telephone number (2222).27,184 _{The hospital switchboard activates the emergency team via the} pager system. The emergency page consists of a loud alarm followed by an audible description of the location of the emergency, for example “adult emergency,

Birmingham Heartlands, ward 4.” On arrival at the emergency, the team delivers care in accordance with Resuscitation Council (UK) guidelines.14

3.3.3 Cardiac arrest equipment

Across Heart of England NHS Foundation Trust, there are 157 cardiac arrest trolleys. Trolleys contain essential emergency equipment stored in sealed trays and a

defibrillator.185 _{A Phillips MRX QCPR defibrillator (Philips Healthcare, Andover,} Massachusetts, USA) is located on most trolleys. Trolleys in low-risk areas may be equipped with a Phillips Heartstart XL defibrillator (Philips Healthcare, Andover, Massachusetts, USA) or a Phillips FR2 automated external defibrillator (Philips

Healthcare, Andover, Massachusetts, USA). All trust defibrillators have a CE mark, and were used within their licence during this study.

Phillips MRX QCPR defibrillators

The Phillips MRX defibrillator (Philips Healthcare, Andover, Massachusetts, USA) has monitoring, defibrillation, pacing, and cardioversion functions. The device is licensed for adult, paediatric, and neonatal use. At HEFT, all Phillips MRX defibrillators have been

upgraded to incorporate QCPR technology. During CPR, a puck measuring 15cm by 7cm is placed on the patient’s chest and chest compressions are delivered on top of the puck (Figure 3-1). The puck records force and acceleration. This technology enables the defibrillator to record CPR quality metrics during cardiac arrest events.

Real-time audiovisual feedback

The Phillips MRX QCPR defibrillator (Philips Healthcare, Andover, Massachusetts, USA) has the capability to provide real-time audiovisual feedback. Visual feedback is provided on the defibrillator display and on a small screen on the puck. The defibrillator display is split in two sections. The upper half displays the electrocardiogram (ECG). The lower half contains two panels that display visual information about CPR quality (Figure 3-2). Audio feedback is provided by voice prompts, such as “release pressure between compressions” and “compress deeper.” Where several CPR quality metrics require correction at the same time, the verbal prompts follow a system of prioritisation.

Lower panel shows compression depth and incomplete release. Each

inflection represents a compression. A white dot at the

top of the inflection indicates incomplete release Top panel shows chest compression rate, number of seconds since last compression

and ventilation rate

3.3.4 Cardiac arrest incidence at HEFT

Cardiac arrest events attended by the hospital emergency team are routinely audited by the HEFT resuscitation service for audit and quality assurance purposes.15,186

Analysis of Trust data from the last four years (2010-2013) demonstrates a median of 40 (interquartile range (IQR): 32-46.5) cardiac arrests per month attended by hospital emergency teams. Birmingham Heartlands Hospital has the highest median incidence of cardiac arrest events per month (Table 3-1). Despite having the lowest overall median monthly cardiac arrest incidence, Solihull Hospital has the highest incidence of out-of-hospital cardiac arrest events. These differences reflect differences in hospital size, case-mix, and service configuration. Ambulance alerts at Good Hope Hospital and Birmingham Heartlands Hospital are usually managed by emergency department staff. In contrast, Solihull Hospital ambulance alerts are managed in the acute medical unit by the hospital emergency team.

Table 3-1: Monthly cardiac arrest incidence at Heart of England NHS Foundation Trust: January 2010-December 2013

Hospital site

Total BHH GHH SH p-value*

Total CA per month- median (IQR) 40

(32-46.5) 19 (15.25-24) 11 (7.25-13) 9 (7-12) p<0.01

In-hospital CA per month- median (IQR) 34 (28-40.75) 19 (15-23) 10 (7-12) 6 (3.25-8) P<0.01

Out-of-hospital CA per month- median (IQR) 4.5 (3-7) 0 (0-0.75) 1 (0-1) 4 (2-6) p<0.01

*p-values calculated by Kruskall-Wallis test. CA- cardiac arrest. IQR- interquartile range. BHH- Birmingham Heartlands Hospital. GHH- Good Hope Hospital. SH- Solihull Hospital