Palliative Care in the Vegetative State Emily R. Levy UVM Palliative Care Rotation 8/26/2010

Vegetative State: What is it? • Patient with severe anoxic brain injury who progresses to a state of wakefulness without awareness. • Refers not to “vegetable” but to “vegetate”. • Criteria2 include: No evidence of awareness No evidence of sustained, reproducible, purposeful, or voluntary behavioral responses to visual, auditory, tactile, or noxious stimuli No evidence of language comprehension or expression Sleep-wake cycles Bowel and bladder incontinence Variably preserved cranial-nerve and spinal reflexes

Persistent and Permanent Vegetative States •“Persistent Vegetative state” present one month after acute traumatic or nontraumatic brain damage •“Permanent vegetative state” denotes irreversibility; 3 months after non-traumatic brain damage and 12 months after traumatic injury

Minimally Conscious State: What is it? • As with PVS – severe alteration in consciousness – demonstrate sleepwake cycles

• In contrast to PVS – may demonstrate visual tracking – follow simple commands – signal yes or no – have intelligible verbalization or purposeful behaviors

Life (?) in a Vegetative State

After a Vegetative state becomes ‘permanent’ by diagnostic criteria, it is extremely unlikely that it will progress to a minimally conscious state.1

Epidemiology In the United States, it is estimated that there may be between 15,00040,000 patients who are in a persistent vegetative state3

Can patients in vegetative states experience pain? • Critical role of thalamo-cortical interactions for meaningful conscious experience • Thalamo-cortical connections are drastically altered, and/or destroyed, in vegetative states9

Does Consciousness = Experience • Unproven whether cortical-mediated consciousness is required for sensory (or pain) perception • Children with hydranencephaly are discriminatively aware, despite total absence of functional cortex5

What is Pain? An unpleasant sensory and emotional experience associated with real or potential tissue damage • Chronic and Neuropathic pain associated with central sensitization (and psychological states) • Acute and Nociceptive pain involve Lateral (thalamus, somatosensory cortices) and Medial (thalamus, cingulate cortex, amygdala, hippocampus, hypothalamus) pain systems • Patients in vegetative states could have triggers of both nociceptive and neuropathic pain

The Medical Profession’s Opinion: •

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2009 survey on >2000 medical professionals: "Do you think that patients in a vegetative state can feel pain?" 68% of the interviewed paramedical caregivers (n=538) and 56% of medical doctors (n=1166) "yes” 8 Non-MD professionals, religious caregivers, and older caregivers more likely to think VS patients experience pain Following professional background, religion was the highest predictor of caregivers' opinion

PET Scan Evidence: Pain in Vegetative States • •

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PET scan to investigate cerebral blood flow after stimulations of median nerve Controls: painful stimuli activated a large set of areas involved in pain processing (brainstem, thalamus, somatosensory cortices, insula, superior temporal and anterior cortices) VS patients: activated brainstem, thalamus, and primary somatosensory cortex. Failed to activate the secondary somatosensory cortex or the other higher order associative cortices.9 Residual perception in primary (peripheral) pain pathways.

Should we treat pain in vegetative states? • Ethically, based Beneficence and Nonmaleficence, assuming a patient feels pain is most appropriate way to approach Vegetative States.6 • 40% of Minimally Conscious patients are initially misdiagnosed as being in a vegetative state; MCS patients have conscious perception of pain6,13 • Even in a true Permanent Vegetative State, pain detected by stereotypical responses or flexion withdrawal after noxious stimuli; there may be experience of pain at some level

If a vegetative state patient had pain, how would we know? •

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Diaphoresis, tachycardia, tachypnea, and posturing/increased tone, may signal a type of “pain”10 Injuries which cause pain in conscious people should be assumed to cause pain in VS patients Multiple Behavioral Scales can assess for Pain Response: The Glasgow Coma Scale, Coma Recovery Scale, and the Coma/Near-Coma Scale6

Prophylactic Pain Treatment • In vegetative states, practice prophylactic pain management based on known injuries and clinical presentation • Consider pain in VS patients with spasticity, contractures, fractures, pressure sores, soft tissue ischemia, and postsurgical sites • Consider neuropathic pain in patients with cortical atrophy, peripheral nerve injury, or chronic nerve stimulus

Pharmacologic Choices • Mild: NSAIDs, Aspirin, Acetaminophen • Moderate: Ketorolac, Mixed opiates with acetaminophen, Tramadol • Severe: Morphine, Pentazocine, Nalbuphine, Buphrenorphine, • Neuropathatic: TCA and SNRI antidepressents, anticonvulsants • Contractures: Botox or Baclophen • Secretions: Glycopyrrolate

Comfort Care • Suctioning, providing tracheostomy care, turning, feedings, cathing or toilet care, bathing, eye moistening, and dressing are routine comfort care requirements by nurses who care for PVS patients11 • Alternative therapies include Eastern Medicine, acupunture, Reiki, prayer, energy healing, and music

Summary

• Within the United states, thousands of patients are in permanent vegetative states today • Vegetative State patients may detect pain in a variety of ways; however, they are unlikely to experience it via cortical processing • Ethically, we should prophylactically treat patients in vegetative states • Medically, we should address both nociceptive and neuropathic pain. • More research is needed to increase our understanding of sensation in vegetative patients and find medical guidelines for pain management.

References 1. 2. 3. 4. 5.

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http://www.coma.ulg.ac.be/index.html The Multi-Society Task Force on PVS (1994). Medical aspects of the persistent vegetative state. N. Engl. J. Med. 330: 1499-1508. Hirsch, Joy (2005-05-02). Raising consciousness. The Journal of clinical investigation (American Society for Clinical Investigation). 115 (5): 1102. Monti MM, Laureys S, Owen AM. The vegetative state. BMJ. 2010 Aug 2;341:c3765. Shewmon DA, Holmes GL, Byrne PA. Consciousness in congenitally decorticate children: developmental vegetative state as self-fulfilling prophecy. Dev Med Child Neurol 1999; 41:364373. Schnaker C, Zasler N. Pain assessment and management in disorders of consciousness. Current opinion in neurology (2007) volume: 20 issue: 6 page: 620-6 Gill-Thawaites H. Lotteries loopholes and luck: misdiagnosis in the vegetative state patient. Brain Inj 2006; 20 (13-14): 1321-1328 Demertzi A, Schnakers C, Ledoux D, Chatelle C, Bruno MA, Vanhaudenhuyse A, Boly M, Moonen G, Laureys S. Different beliefs about pain perception in the vegetative and minimally conscious states: a European survey of medical and paramedical professionals. Prog Brain Res. 2009;177:329-38. Laureys S, Faymonville ME, Peigneux P, Damas P, Lambermont B, Del Fiore G, Degueldre C, Aerts J, Luxen A, Franck G, Lamy M, Moonen G, Maquet P. Cortical processing of noxious somatosensory stimuli in the persistent vegetative state. Neuroimage. 2002 Oct;17(2):732-41. Jennett B. Thirty years of the vegetative state: clinical, ethical and legal problems. Prog Brain Res. 2005;150:537-43. Montagnino BA, Ethier AM. The experiences of pediatric nurses caring for children in a persistent vegetative state. Pediatr Crit Care Med. 2007 Sep;8(5):440-6. http://www.scholarpedia.org/article/Vegetative_state Boly M, Faymonville ME, Schnakers C, Peigneux P, Lambermont B, Phillips C, Lancellotti P, Luxen A, Lamy M, Moonen G, Maquet P, Laureys S. Perception of Pain in the Minimally Conscious with PET Activation: An Observational Study. Lancet Neurol. 2008 Nov;7(11):97980.