POSTOPERATIVE DELIRIUM


Life expectancy in the USA as of the most recent data is 78.61 years. Along with longer life span we have a every increasing number of surgery. With out-patient surgery rapidly growing year over year. The population over 65 years are living a more active life still and are requiring more surgical intervention. Our peri operative technologies have improved to allow us to provide safer care to those at the extremes expectancy range. WIth this improvement and comes many additional questions. The question of post op delirium continues to be a problem and will increase as the populations ages and more surgical procedures are available.

How the older patient is cared for in the peri operative time frame is and will continue to be of special concern to themselves, families and increasingly to payors. The process of getting from diagnosis to the surgical suite is basically divide in 2 routes, either via he emergency room or the physician office. The peri operative preparation is as import as the intra operative care and involves many, however as an Anesthesiologist i will present the process from my vantage point.
The care of any patient starts with the basics, taking a good history. For all patients under the care of an anesthesia provider taking a focused and directed history is vital to the safe delivery of appropriate care. For the older patient extra attentions should be placed on history of delirium in the post operative period which i would suggest should be considered to include the first 24 hours post PACU discharge. Other vital components to evaluate include vision impairment and hearing loss. For the visually impair consider how soon after arrival in PACU to return glasses. For the hearing impaired do they use hearing aids, can they be left in for the procedure. Does the patient lip read. Even for those that do on lip read, looking directly at them, speaking clearly with proper enunciation without shouting works very well to transmitted data.

Carefully look over medications for hints to treatment for early dementia. Ask about early dementia. What happened after last surgery. Who will be present in the post operative period?

There is no clear evidence that anesthesia specifically is the cause of post operative delirium. The choice of anesthesia should be based on what intervention will provide for the safest working conditions and facilitate a rapid low pain recovery.  For those with dementia the suggestion that regional alone maybe advantageous is not as clear to me as it maybe to others. From my experience regional as the sole anesthetic in a demented even for very minor procedures will be a challenge because of the lack of circumstantial awareness from the patient. The lack of awareness can and often leads to lost of cooperation and increased risk of morbidity to the patient. The primary anesthetic must provide the appropriate working conditions firstly. The demented patient like all patient must first be in optimal surgical condition. General anesthesia is often the most optimal choice. General anesthesia is not one thing but many varied combination of drugs and this is where the judgement of the anesthesia provider can be very helpful. From my vantage point the goal is to provide the most advantageous conditions using the lowest dose of the fewest drugs required. A monitor that was dependable in the judgement of anesthetic depth would be of great utility in the older patient. The BIS monitor is claimed by some to be such a monitor, but many others find it inconsistent and unreliable. I have not seen any evidence that convinces me that it provides and advantage. It may provide some advantage but that advantage is not clear to me. The traditional monitoring of anesthetic depth includes observation of changes in vitals and direct observation of the patient may be insufficient to guarantee adequate depth but is still the best we have. A vigilant provider is still the best monitor. I hope that one day soon we will have an even better monitor. Without that monitor the provider needs to be conscious to balance depth with risks of post operative delirium. The drugs that we use to maintain anesthesia are important potential risk point and one area that is especially concerning are the anticholinesterases. These drugs are used as apart of the cocktail for reversal of paralysis and can cause delirium and should be used with caution. The optimal situation would be to not need them, meaning if necessary we should avoid paralysis. However, if paralysis is needed full reversal should be used because incomplete reversal could make the post operative situation worse. Additionally making sure all our anesthetic if below therapeutic levels before going to the PACU is beneficial.

Once the optimal condition for surgery have been meet and the anesthetic is optimized to decrease the risk of post operative delirium the patient needs to be cared for in a PACU that continues to  optimize recovery. The environment needs to the at an appropriate temperature with appropriate lighting and quiet. Use the minimum required monitors to get the job done. The nurse in the PACU is a vital partner, she needs to orient the patient to date time and location. Orient, orient and orient again. Assurance of adequate hydration, pain control, empty bladder, treatment of nausea if present, prevent hypoxia are all vital. If delirium occurs, low dose benzodiazepine and family at bedside should be considered. The use of regional anesthesia is a great tool to assist the post operative period. I find the most utility of regional in the patient with dementia or at risk of delirium is in its ability to provide significant long-lasting pain control that decreases the amount of opioids needed in the recovery period.
Special attention to the needs of the older patient at risk for post operative delirium is a worthy goal. However, we must not be lead from first principles. We must provide a safe environment for the procedure. With careful planning and attention to detail we may be able to decrease the risks, but we should not lose site of the facts. Fundamentally, there is no good evidence that the type of anesthetic correlates with risk of post operative delirium. The only consistent fact is that the patient has had surgery. Teasing out the specific component of the peri operative environment that increases risk is still some way off. What anesthesia providers need to provide safe conditions that decrease risks based on the evidence we have.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s