Mental Capacity Act: Medical Decision Making

Assessment of Capacity and Refusal of Care

• A patient with an ischaemic leg and mild dementia is assessed for capacity to make a decision about their care.
• The patient's capacity is assessed through a conversation to determine if they can understand, retain, and communicate their decision and weigh up the risks and benefits.

Mental Capacity Act 2005

• A two-stage process to assess capacity:
  • Stage 1: Determine if the person has an impairment or dysfunction of mind or brain.
  • Stage 2: Determine if the impairment or disturbance affects their ability to make a particular decision.

Criteria for Capacity

• A person lacks capacity if they cannot:
  • Communicate their decision
  • Understand information about the decision
  • Retain that information in their mind
  • Evaluate, use, or weigh that information as part of the decision-making process

Decision-Making Process

• If the patient lacks capacity:
  • Check for an advanced directive or Lasting Power of Attorney (LPA)
  • Apply the doctrine of emergency or doctrine of interim (if short-term) or best interest principles (if long-term)
  • Any action taken must be proportionate to the risk the patient is putting themselves at and believed to be in their best interests

TCA Overdose and Safeguarding

• Estimated dose of 10-30mg/kg can be life-threatening within 6 hours.
• Monitoring is crucial at least 6 hours post-ingestion.

Clinical Features

• Anticholinergic symptoms: dry mouth, flushed skin.
• Alpha blockade and Na+ blocking effects.
• Sympathomimetic symptoms: mydriasis, dry mouth, sweating, agitation, tremor, clonus, hyper-reflexia.

Cardiovascular Complications

• Arrhythmias, hypotension, and ECG changes.
• PR and QT prolongation.
• QRS >100ms increases risk of seizure.
• QRS > 160ms increases risk of ventricular tachycardia (VT).

Treatment

• Sodium bicarbonate (50ml 8.4% or max 6mmol/kg) administration.
• Hyperventilation (pH 7.5-7.55) to reduce sodium channel blocking effects.
• Lidocaine and Mg for arrhythmias despite Na+ blocking effects.
• Lidocaine and Mg thought to outcompete TCA and reduce Na channel blocking effects.

Assess a patient's capacity to make medical decisions in a scenario where a paramedic has already evaluated their medical condition. Consider the patient's situation and background to create a management plan.