We contacted all 166 (100%) anesthesia departments by telephone. In total (after the repeat telephone survey described above) we identified 53 departments who offer PCPET (32%).
Online survey
We received a total of 128 responses to the survey. Five of these were duplicate responses from individuals in the same department. Only the first response received from each of these departments was included in the analysis. As such our overall response rate was 74% (123/166).
We received 49 (40% of total) responses from departments that offer PCPET and 74 (60% of total) responses from departments without access to PCPET services.
Departments without PCPET services (n= 74)
Thirty-five (47%) of those who responded have made an attempt to set up PCPET services that was unsuccessful. The reasons given for failed attempts included: financial (43%), perceived lack of clinical need (11%) and insufficient evidence of benefit (6%).
Thirty-three departments (45%) have not attempted to set up a service. Reasons stated for this included: financial constraints or lack of resources (39%), inappropriate case mix (9%), training issues (3%), lack of support from other departments (3%) and conflicting evidence for clinical benefit (3%).
Six departments (8%) are in the process of setting up a peri-operative CPET service.
The survey responses rates are summarized in Figure 1.
Departments with PCPET services (n= 49)
The majority of respondents to the survey were anesthetists (90%), the remainder being clinical scientists (6%) and physicians (4%).
Logistical aspects of PCPET services
Forty-five respondents (92%) indicated that testing is performed in-house. One department refers patients to a private CPET clinic as well as testing patients in-house themselves.
The majority of tests are conducted by anesthetists. Some are conducted by a variety of other clinicians and non-clinicians (Figure 2). Three respondents do not have any assistance during testing (6%) and 19 (39%) are assisted by a trained cardio-respiratory technician. Other assistance during testing includes: operating department practitioners (14%), pre-assessment nurse (14%), nursing auxiliary (6%), anesthetic practitioner (2%), physicians’ assistants in anesthesia (2%) and research nursing staff (2%).
Clinics are operated in a variety of locations: in the pre-assessment clinic (39%), in the respiratory laboratory/clinic (27%), in the cardiology department (12%), in a ward area (4%), in the outpatients department (4%), in a research laboratory (2%) and on the intensive care unit (2%). The responsibility for maintenance, cleaning and sterilization of reusables and stocking of disposables lies with the clinician (20%), technician (49%) or a nurse (10%).
Clinical aspects of PCPET services
Referrals for CPET are received from multiple sources. Departments receive referrals from surgical colleagues (76%), anesthetic colleagues (69%), the pre-assessment clinic (67%) and from multi-disciplinary team meetings (35%). Interestingly only 22% of departments include strict predetermined criteria as a part of their referral pathway. Of the total, 8% reported receiving referrals from cardiologists and respiratory physicians.
Twenty-four (49%) departments consent their patients verbally for PCPET, 11 (22%) require formal written consent and seven (14%) do not consent their patients prior to testing. This is a significant deviation from the practice in most cardiology exercise labs, where formal consent is not obtained prior to a treadmill test.
All respondents have access to a cycle ergometer for testing. However, the majority (55%) of departments only have access to a cycle ergometer, thereby limiting the range of patients who are physically able to perform the test. In addition to a cycle ergometer, eight (16%) departments have access to a hand crank ergometer and seven (14%) have access to a treadmill ergometer. One department (2%) has access to bicycle, hand crank and treadmill ergometers.
A variety of sub-specialty patient groups are tested, as depicted in Figure 3. Other patient groups tested are pediatric cardiology, ICU follow-up and adult congenital heart disease follow-up (Figure 3).
The majority of respondents use the anaerobic threshold (AT) (90%), Ve/VCO2 (71%), peak VO2 (59%), and Ve/VO2 (31%) to risk-stratify patients. A variety of other CPET-derived parameters were also reported as being used for risk stratification. For example: onset of ischemia, oxygen pulse, heart rate response, blood pressure response, desaturation, ventilator limitation, VO2/work rate slope and Ve/VCO2 slope.
The majority of respondents run their tests to the patients’ symptom limited maximum (71%). This provides evidence for the need for a clinician to be present during the test on the grounds of safety. Some terminate tests after the patient has exercised to their anaerobic threshold (14%) or to their target peak VO2 (6%). Other responses include achieving predicted maximal heart rate and ischemic ECG changes.
The majority of respondents use the results for individual patient risk stratification and counseling (86%) and to allocate patients to an appropriate level of post-operative care (84%). Some departments use the results to determine the level of intraoperative monitoring (47%). Other uses reported by respondents include: for clinical diagnostics, to modify surgical procedure (in support of funding applications for less invasive procedures in high risk cases) and to assess the need for pre-optimization.
The majority do not recommend cancellation of an individual case based on the CPET result (55%). However, 33% of respondents do recommend cancellation of cases based on individual CPET results. There were many comments left for this question implying that the decision to cancel cases is more complex than this. The comments highlighted that CPET results advise risk and that the final decision lies with the patient, surgeon and, in some cases, the anesthetist. Some respondents felt strongly that the decision to cancel a case is not for the CPET clinic.
The median number of tests performed per clinic session was 3 (range 0.5-7.5, mean 3.2, mode 3, SD 7.3). The median number of PCPET clinic sessions per month was 6 (range 0.5-40, mean 8.4, mode 4, SD 1.5). Of the 53 departments identified by the telephone survey we received 49 responses. Of these 42 gave estimates regarding the output of testing services. If we substitute mode values (most conservative estimate) for missing data we estimate that over 15,000 PCETs are performed each year in England (Figure 4).
Administrative and managerial aspects of PCPET services
We were keen to find out how the administrative aspects of these clinics were managed. The questions ranged from organizing appointments to calibrating and validating the equipment and getting the reports to the referring clinician.
Appointments are arranged using written, formal appointment letters with an information leaflet in the majority of cases (76%). Other methods include: by telephone (8%) or written, formal appointment letters without information leaflet (8%).
The PCPET equipment is owned either by anesthetic departments (51%), respiratory departments (20%), cardiology departments (10%), clinical measurement/physiology departments (4%), surgical departments (2%) or clinical research facilities (2%).
Respondents reported a variety of administrative support as part of their service infrastructure. These include: departmental secretary (39%), pre-assessment clinic staff (27%) and own secretary (10%). Several respondents commented that administrative tasks are undertaken by clinicians. Nine services (18%) have no administrative support.
Where anesthetists perform PCPET, the majority of sessions are considered as a clinical professional activity (51%) in job plans. Some sessions are in supporting professional activity time (12%), and others in the clinicians’ own time (8%).
The majority of tests performed are logged onto the hospitals’ patient administration systems (67%); 12% are not logged and 10% of respondents did not know if tests were logged.
The primary care trust (PCT) is billed for the patients tested in only 37% of departments. No payment is received for testing in 31% of responding departments and 24% of respondents did not know if the PCT was billed.