PART 2: Mental Capacity in the Resus Bay (The MCA 2005 Framework)

PART 2: Mental Capacity in the Resus Bay (The MCA 2005 Framework)

• Core Dilemma: Determining whether an intoxicated, head-injured, septic, or suicidal patient aged 16+ has decision-specific and time-specific capacity to refuse urgent investigation or treatment.
• The 5 Statutory Principles (MCA s.1): (1) Presume capacity (burden of proof is on the clinician on the balance of probabilities), (2) Maximize practicable support to help the patient decide, (3) Unwise decisions do not equal lack of capacity, (4) Act in Best Interests, and (5) Choose the Least Restrictive Option.
• The 2-Stage Functional Test (MCA ss.2–3):

1. Stage 1 (Diagnostic): Is there a permanent or temporary impairment/disturbance in the functioning of the mind or brain?
2. Stage 2 (Functional): Can the patient Understand, Retain, Use or Weigh, and Communicate their decision? (With a proven Causal Nexus linking Stage 1 to Stage 2 per PC v City of York Council).

• MRCEM/FRCEM Exam Trap: Stopping at "Understanding." Patients with severe suicidal depression, severe anorexia (Re E), or acute needle panic (Re MB) often pass Understand and Retain but fail Use or Weigh because their pathology prevents them from balancing survival against death. Under MCA s.4(3), temporary incapacity (e.g., an intoxicated head injury) cannot wait if delay risks death or irreversible brain injury.