Swansea Minor Injuries and Ambulatory Care Unit

GP Calls with Chest Pain (presumed cardiac cause)-AcuteGP Unit

Prepared by: Dr Chris Johns

Background

Often there are considerable delays with discharging patients who are sent to MAU (Singleton) with non specific chest pain (presumed cardiac). The 6 hour high sensitive Troponin T is used as complimentary too to clinical assessment and ECG.

If GPs or the ambulance service took the first blood test at source when referring the patient it would relieve some of the pressures on SAU on discharge times

All STEMI, new LBBB and true post MI go direct to Morriston for interventional cardiology. Many patients with no “acute” change on their ECG and have a history the GP is consistent with cardiac pain come to Singleton.

High Sensitive Troponin T

  1. Results will be reported in ng/L (previously microg/L). The lowest result will be 3ng/L, which would be 0.003 microg / L in the old units.
  1. A diagnosis of an acute cardiac event is a clinical history and findings, supported by either compatible Troponin T result (s), appropriate ECG changes or evidence from imaging.
  1. The first sample should be taken at presentation, with a second rule in/rule out sample at 6-9 hours later.
  1. Significant change:
  1. <20% change: Not consistent with acute myocardial event.
  1. 20-100% change: significant rise, but further evaluation required to distinguish acute and chronic causes.
  1. > 100 % change and at least one sample >14 ng/L: consistent with myocardial infarction.
  1. Raised Troponin can be due to ischemic cardiac events or non-ischemic cardiac episodes such as peri/myocarditis, arrhythmias, valvular disease or heart failure. With hs-TnT many patients with chronic stable pre-existing cardiac conditions will have a Troponin T result above 3ng/L, and this does not indicate an acute cardiac event unless the above conditions are met.
  1. Many patients admitted to hospital with an acute illness will have an elevated hs-TnT and this does not necessarily reflect an acute myocardial event. Non-cardiac causes of an elevated TnT include stroke, infection, pulmonary embolism, cor pulmonale and renal failure.
  1. A normal Troponin at 6-9 hours does not rule out myocardial ischaemia

Further advice on interpretation can be obtained from the duty Clinical Scientist / Chemical Pathologist on MorristonHospital, ext 3036 or princess of WalesHospital, ext 2339.

Procedure

AcuteGP role

If GPs and ambulances are encouraged to take the initial set of bloods by AcuteGP to include-

FBC

Biochemistry-renal, liver profile, lipids, glucose

Hs-TnT

CRP

Clotting screen

  • One purple, one gold, one blue and on grey bottle.
  • Bloods to be brought in personally by patients and NB marked on forms the time of phlebotomy.

SAU role

  • Accept GP blood test and fill in Fast Track yellow form
  • Organise 6 hour sample
  • Action all results