Surgery and the older patient - technical
Formerly, advanced age was regarded as a contraindication to many surgical procedures but advances in surgical techniques and intensive care procedures have changed this attitude. Biological, rather than chronological, age is the important factor, and many elderly people now undergo major surgical procedures and recover successfully. At least 25 to 30% of all surgery is undertaken in those aged 65 years and over. Increasingly, it is being recognized that it is not age itself, but rather the severity of the illness and the presence of comorbidity, that predicts complications and fatality.
Preoperative assessment and evaluation
The patient should be assessed for evidence of comorbidity and other risk factors that might influence surgical outcome. This is not necessarily to decide whether or not surgery is appropriate, but rather to plan the aftercare in a way that minimizes the impact of these risk factors. It is up to the patient and their family, together with the surgeon, to make the decision once they are in a position to make an informed decision.
Preoperative evaluation is best undertaken by considering the patient’s history, conducting a physical examination, and assessing the relative laboratory investigations. In most cases, careful assessment of cardiopulmonary status is of major importance. Other important factors include the medications, both prescribed and over the counter, evidence of nutritional status, cognition, and evidence of psychiatric comorbidity such as depression, and also the patient’s functional level and quality of life.
Investigations should include the usual laboratory screen covering basic haematological and biochemical indices and an ECG. Many would argue for a chest radiograph in appropriate circumstances, especially if there is clinical evidence of cardiac or pulmonary disease.
Peri- or intraoperative cardiovascular complications are usually the major concern. As already indicated, this is probably not a function of age itself, but rather that the latter may be a marker for presurgical cardiovascular pathology. The risk has to be put in the context of the nature of the surgery. It is also necessary to remember that there are physiological changes in the cardiovascular system as a person ages that may lead to an older person being less able to tolerate fluid overload, and hypotension. Another important point is that myocardial infarction in an older person may well be silent, and this should be considered a possibility in any person who shows signs of cardiac decompensation.
Major clinical predictors of increased risk from cardiovascular complications include recent myocardial infarction, significant or unstable angina, severe valvular disease, and significant arrhythmias. Their significance depends on the nature of the surgery that is contemplated. Where uncertainty exists, a full cardiovascular assessment by a cardiologist may be necessary, including exercise testing if this is practicable.
Pulmonary complications are the other major factor determining morbidity and mortality in a patient undergoing surgery. Again, it is not age itself, but the combination of the physiological changes associated with ageing and the presence of preexisting pulmonary comorbidity that are important, the consideration of biological as opposed simply to chronological age. A 70-year-old may have been smoking for 50 or 60 years while a 50-year-old smoker would have acquired 20 years less smoking-induced morbidity. Where there is evidence of respiratory disease, preoperative pulmonary function testing is essential if major surgery is under consideration. Where pulmonary disease constitutes a significant surgical risk, delaying surgery while optimizing treatment for the patient’s pulmonary disorder will usually be worthwhile, especially if this can be accompanied by stopping smoking. As in the case of cardiovascular disease, early mobilization is valuable and will reduce the chance of postoperative lower respiratory tract infection and atelectasis.
Renal and hepatic function can contribute to perioperative risk. Careful attention must be given to fluid balance and electrolyte levels. It is unsatisfactory to rely upon a simple creatinine measurement as an indicator of presurgical renal function. Hepatic function, unless significantly impaired, is usually not a major consideration but one must bear in mind that many anaesthetic drugs are subject to hepatic metabolization and excreted via the biliary system.
The nutritional state of the patient is important, as a malnourished elderly patient has a significantly increased risk of infection, delayed wound healing, and death.
The expected level of function will depend on how the patient has functioned in the recent past, noting any functional decline and what improvement the surgery may achieve. The geriatrician may be the first to inquiry systematically into the patient’s prior state of function. This can lead to a mediating role, between the perspectives of the patient, family, and the surgeon on how the current level of function might be improved, or even threatened, by a given procedure. An elective right total hip replacement might relieve pain, but is highly unlikely to improve walking if a left-hip flexion contracture has developed.
This has proved effective in decreasing postoperative infection rates in a number of different surgical operations and may be particularly important in older people because of their age-related impairment of immunological function. Antibiotic prophylaxis is employed across a range of surgical procedures where the risk of infection, even if low, would create serious problems, e.g. where a foreign body such as a joint prosthesis is being implanted, and similarly for prosthetic valves. The antibiotic chosen is targeted against the most likely organisms to be involved. The dose is determined by the need to produce a high concentration around the time of surgery.
Prevention of endocarditis in those with damaged or prosthetic valves is an important consideration in older people, so many of whom have clinical evidence of possible valvular pathology. If necessary, further investigation such as echocardiography, may be required to discover whether a clinical finding, such as a bruit, is indicative of a damaged valve.
In general, the protocol for using antimicrobial prophylaxis for surgical procedures will be a standard part of the surgical protocol in each unit, often in conjunction with a microbiologist, and will probably not be determined by a physician’s or a geriatrician’s assessment.
Choice of anaesthetic procedure
This should usually be left to the anaesthetist. Sometimes, however, it requires a ‘team’ decision involving the geriatrician as well as the surgical and anaesthetic services, e.g. when deciding on general vs a more peripheral anaesthetic technique. Many older people will benefit from the latter, especially where there is cardiac or pulmonary comorbidity, even though this approach does not eliminate all the complications that are usually associated with general anaesthesia.
A protocol for the postoperative management of elderly patients should rightly be a standard part of the surgical approach, and much will rely upon the nursing as well as the medical staff involved. The geriatrician’s main contribution to postoperative management should begin at the preoperative stage, when a patient’s particular postoperative risks are detailed and a strategy recommended to minimize them. These include delirium and its management, adequate pain control to facilitate respiratory function, and early mobilization to avoid venous thrombosis and pressure sores. Intraoperative use of indwelling catheters may lead to urinary tract infections, and postoperative urinary retention may be a problem in elderly men with prostatic hypertrophy.
Although a geriatrician is often asked to assess a patient preoperatively, particularly for surgical risks and their reduction, it is important to consider strategies to reduce postoperative complications and those occurring in the operating theatre. Surgery, even major surgery, should never be denied a person solely based on their chronological age. A balanced decision, involving the patient and their family as well as their medical attendants, should be made in each case depending upon biological age and comorbidities, severity of risks, quality of life, and the prognosis of the underlying condition requiring surgery. Many elderly people tolerate major surgery and if carefully managed return to a good quality of life.