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Weve done many columns on postoperative delirium. But
delirium in the perioperative period is not limited to the postoperative
period. It may also occur pre-operatively or during the operative period
itself. A recent study from the Pennsylvania Patient Safety Authority (Taylor
2021) discussed delirium in
these other periopeative periods and its association
with anesthetics and adjunct agents.
The researchers queried the Pennsylvania
Patient Safety Reporting System (PA-PSRS) database for event reports to
identify bouts of delirium/ agitation associated with anesthetics and/or
adjunct agents that occurred during the pre-, intra-, or postoperative period
and identified 97 event reports from 63 healthcare facilities over a two-year
period. While postoperative delirium was most commonly seen
(84%), delirium was also seen preoperatively in 8% and intraoperatively in 8%.
An
example of a pre-operative bout of delirium/agitation was a patient scheduled
for an esophagogastroduodenoscopy (EGD who was given propofol in preparation
for the procedure. He became extremely agitated and thrashed on the stretcher.
The physician then canceled the procedure and recommended the patient have the
procedure completed at a hospital and under general anesthesia.
The adverse behaviors encountered in the reports included combativeness,
agitation, kicking, thrashing, exiting or
attempting to exit from a bed or table, and disruption, removal or attempted
removal of apparatus such as intravenous lines, catheters, oxygen, and
nasogastric tubes. Some of the specific patient injuries included abrasions,
bruises, lacerations, or skin tears, prolapse/dehiscence, tooth loss, asphyxiation,
hematoma, and progressive ischemia.
While
those with a preoperative bout of delirium or agitation suffered minimal harm,
88% of the preoperative events resulted in a procedure cancellation.
Speaking of interventions, a recent German study (Deeken 2021)
showed that a multifaceted multidisciplinary prevention intervention reduced
postoperative delirium occurrence and days with delirium in older patients
undergoing different elective surgical procedures but not cardiac procedures. First,
structured delirium education was provided to clinical caregivers at each site.
Then, the study delirium prevention team assessed patient delirium risk factors
and symptoms daily. Prevention was tailored to individual patient needs and
could include: cognitive, motor, and sensory
stimulation; meal companionship; accompaniment during diagnostic procedures;
stress relaxation; and sleep promotion. Overall, the intervention reduced
postoperative delirium incidence (odds ratio, 0.87, P = .02) and
percentage of days with delirium (intervention 5.3% vs. control 6.9%;
P = .03). The effect was significant in patients undergoing
orthopedic or abdominal surgery (odds ratio 0.59, P = .047) but not
cardiac surgery (odds ratio, 1.18).
In
the PPSA article, Taylor et al. offer an intervention package, based on
previous literature and ongoing practices at VA Pittsburgh Healthcare System,
that staff should critically review and consider implementing at their
facility. That includes screening for risk factors for delirium ahead of the
procedure and meeting with the high-risk patient and family to identify
triggers that may influence or exacerbate a bout of delirium/agitation. It involves adjusting the environment, preparing
the bed or table to prevent patient harm, and securing any IV access to
minimize the risk of dislodging. Choice of anesthetics/sedating agents is
discussed, especially avoiding benzodiazepines. The package also suggests
considering either dexmedetomidine and/or ketamine (keep in mind the evidence
for use of these agents is still weak in our opinion). During the
surgical/procedural timeout, staff should be reminded that the patient is at
high risk for delirium. As case concludes, staff should call ahead to recovery
room/post-anesthesia care unit (PACU) to initiate intervention protocol for
emergence of the high-risk patient. Postoperatively, triggers should be avoided,
and the bed should be configured to help avoid patient injury should agitation
occur (eg. padding on siderails). A debriefing meeting
with patient and family should be considered, as well as a debriefing meeting
among staff. The authors add the caveat that this proposed intervention package
as a whole has not been experimentally evaluated for
efficacy nor the risk of unintended consequences.
See
our many prior columns (listed below) for discussion of other
nonpharmacological interventions to prevent and manage delirium (eg. the HELP program, ABCDE bundle, etc.).
The
PPSA study focused on delirium or agitation in relation to anesthetics and
adjunct agents. The role of anesthetic agents and adjuncts during surgery in
causing post-op delirium has long been debated. A recent study (Li 2021) found that, in patients aged 65 years and older
undergoing hip fracture surgery, regional anesthesia without sedation did not significantly
reduce the incidence of postoperative delirium compared with general anesthesia.
The study was a randomized, allocation-concealed but open-label, multicenter
clinical trial of 950 patients, aged 65 years and older, with or without
preexisting dementia, and a fragility hip fracture requiring surgical repair
from 9 university teaching hospitals in China. Postoperative delirium occurred
in 6.2% in the regional anesthesia group vs 5.1% in the general anesthesia
group.
But
there are certainly questions about that study. The incidence of delirium was
way lower than we would expect in an elderly population undergoing surgical
repair for hip fracture. The accompanying editorial (Avidan 2021) also comments on that disparity and notes
some methodological issues with the Li study. But it does point out that other recent
studies have also failed to show that general anesthesia is associated with
higher rates of post-op delirium than spinal or regional anesthesia. REGAIN
trial (Regional vs General Anesthesia for Promoting Independence after Hip
Fracture) was a randomized trial to evaluate spinal anesthesia as compared with
general anesthesia in over 1600 previously ambulatory patients 50 years of age
or older who were undergoing surgery for hip fracture at 46 US and Canadian
hospitals (Neuman 2021). There was no significant difference in the
incidence of postoperative delirium, which occurred in 20.5% of patients in the
spinal anesthesia group vs 19.7% in the general anesthesia group.
Delirium is a common complication of elderly patients
having surgery or acutely hospitalized for a variety of medical conditions. It
is associated with a
number of poor patient outcomes,
such as longer hospital stays, increased risk of post-hospital institutionalization,
and accelerated cognitive decline. Patients with delirium have an increased
mortality rate, not only for the current hospitalization but also in the year
following the episode of delirium. Diwell et al. (Diwell 2018) looked
at mortality rates for patients with full-blown delirium and those with subsyndromal
delirium. The hazard ratio (HR) for full-blown delirium was 2.31, and for subsyndromal
delirium 1.26. After adjustment the HR remained significant for the full-blown
syndrome but not for the subsyndromal delirium. Two items from the CAM (Confusion
Assessment Method) assessment tool were significantly associated with mortality
following adjustment: acute onset and disorganized thinking. The authors
conclude there is a dose-response relationship between mortality and delirium, with
full-blown delirium having the greatest risk and subsyndromal delirium having
intermediate risk.
Our understanding of the underlying mechanisms of delirium
is yet evolving. Its underlying mechanism is undoubtedly multifactorial and we know of many contributing factors and
precipitating factors. The reason(s) for the increased mortality are also
unclear. As Diwell et al. point out, some of the features
of delirium itself may lead to complications that could lead to death. For
example, falls are common in those with full-blown delirium and those with
hypoactive delirium might be more prone to aspiration pneumonia. On the other
hand, the nature of the underlying medical conditions that led to delirium may
play a big role in mortality risk. Our personal view is that delirium is a
state of reduced physiologic reserve, much like the reduced physiologic
reserve seen in frailty which is a frequent accompaniment of delirium. That
reduced reserve may render patients more vulnerable both acutely and in the
longer run.
While
delirium thus has prognostic significance, we still need to take steps to prevent
its occurrence and manage it as best we can when it does occur.
Some of our prior columns on delirium
assessment and management:
·
February
12, 2019 2 ER Drug Studies: Reassurances and
Reservations
·
September
17, 2019 American
College of Surgeons Geriatric Surgery Verification Program
·
March
2021 The Fiscal Costs of Delirium
References:
Taylor
MA, Pileggi W. Perioperative Delirium/Agitation Associated With
the Use of Anesthetics and/or Adjunct Agents: A Study of Patient Behaviors,
Injuries, and Interventions to Mitigate Risk. Patient Safety 2021; 3(4): 16-27
published December 2021
https://patientsafetyj.com/index.php/patientsaf/article/view/periop-delirium/printer-friendly
Deeken F, Sαnchez A, Rapp MA, et al. Outcomes of a Delirium
Prevention Program in Older Persons After Elective Surgery: A Stepped-Wedge
Cluster Randomized Clinical Trial. JAMA Surg 2021; Published online December
15, 2021
https://jamanetwork.com/journals/jamasurgery/fullarticle/2787212
Li T,
Li J, Yuan L, et al. Effect of Regional vs General Anesthesia on Incidence of
Postoperative Delirium in Older Patients Undergoing Hip Fracture Surgery: The
RAGA Randomized Trial. JAMA 2021; Published online December 20, 2021
https://jamanetwork.com/journals/jama/fullarticle/2787494
Avidan MS, Whitlock EL, Mashour
GA. General Anesthesia and Postoperative Neurocognitive Outcomes. JAMA 2021;
Published online December 20, 2021
https://jamanetwork.com/journals/jama/article-abstract/2787496
Neuman
MD, Feng R,
Carson JL, et al. for the REGAIN
Investigators. Spinal anesthesia or general anesthesia for hip surgery in older
adults. N Engl
J Med 2021; 385(22): 2025-2035
https://www.nejm.org/doi/10.1056/NEJMoa2113514
Diwell RA, Davis DH, Vickerstaff
V, Sampson EL. Key components of the delirium syndrome and mortality: greater
impact of acute change and disorganised thinking in a
prospective cohort study. BMC Geriatr 2018; 18(1): 24
Published 2018 Jan 25.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5785815/
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