Management of the geriatric trauma patient.

John Moloney

Head, Trauma Anaesthesia,The Alfred, Melbourne

As our population in general ages, an increasing proportion are moving into the geriatric age groups. Older people have significant changes to their normal anatomy and physiology, affecting a broad range of organ systems. In addition, the effects of chronic pathophysiology may be superimposed. These alterations impact on the ability of the elderly to maintain normal physiological functions in the presence stress, including trauma.

The aging population may be more likely to be injured for many reasons, including:

1. Impaired balance and gait
2. Postural hypotension
3. Increased reaction time
4. Syncope
5. Cognitive dysfunction
6. Visual loss

Older trauma victims also have a different spectrum of aetiology. Most trauma in this age group is related to falls, usually mechanical, but potentially syncopal - with its consequent implications. Car accidents account for about ¼, with a significant proportion being as a pedestrian.

Organ system changes associated with aging include:

These organ system changes in the heart, vasculature, lungs, kidneys and liver lead to decreased physiologic reserve: (e.g., the increased A-a gradient for oxygen secondary to FRC decreasing towards closing capacity) means less reserve above baseline.
The thoracic cage is far more fragile, increasing the risk of both rib fractures and pulmonary contusions. The morbidity and mortality in the elderly is higher for similar chest wall injuries.

There may be a number of potentially significant alterations in drug pharmacokinetics and pharmacodynamics. Combined with an increased potential for drug interactions due to pre-existing medications, these can modify the geriatric patient's response to drugs.

Resuscitation:

Geriatric trauma patients should have oxygen administered due to higher A-a gradients. Edentulous patients may be difficult to mask ventilate. Direct laryngoscopy may be more difficult due to decreased cervical spine mobility. Fluids should be administered with care, particularly in the presence of cardiovascular and/or renal disease. Invasive monitoring should be considered early and with a lower threshold.

Perioperative Management:

Anaesthetists must assume that the geriatric multi-trauma patient has limited physiologic reserve and that even minor injuries may become life threatening. Therefore, monitoring intensity and attention to patient response following various stresses are important.
The choice of anesthetic agent, or technique itself, does not appear to be a major determinant of overall outcome. Neuromuscular blocking drugs are higher plasma levels of in the elderly, and their elimination is reduced. These patients are also vulnerable to hypothermia due to pre-existing hypothermia, decreased (heat generating) muscle mass and (insulating) subcutaneous fat.

The bolus dose for patient controlled analgesia (PCA) delivered analgesics generally need to be decreased in the elderly, the lock-out time can remain the same. Caution should be exercised with background infusions.

References:

1. Syllabus on Geriatric Anesthesiology, 2002, G. Alec Rooke.
2. Geriatric Trauma, Joanne Williams, Calvin Johnson, Sharon Ashley and William C. Wilson. In TRAUMA - Emergency Resuscitation, Perioperative Anesthesia, Surgical Management. Volume 1. 2007
3. Hypotension Begins at 110 mm Hg: Redefining "Hypotension" With Data. Eastridge BJ. Et al, The Journal of TRAUMA: Injury, Infection, and Critical Care. 2007.
4. Jacobs DG, Plaisier BR, Barie PS, et al. Practice management guidelines for geriatric trauma: The EAST Practice Management Guidelines Work Group. J Trauma 2003