postoperative delirium in elderly patients

38 AJN ▼ September 2012 ▼ Vol. 112, No. 9 ajnonline.com

HOURSContinuing EducationCE

In 2009, more than 37% of all interventional and surgical procedures in the United States were per-formed on adults ages 65 and older. Patients in

this age group accounted for more than 57% of all coronary artery bypass grafts and 50% of all large bowel resections.1 Given that the average 75-year-old American “has three chronic conditions and uses five prescription drugs,”2 it’s not surprising that post-operative delirium is a frequent complication of sur-gery in elderly patients, with reported incidence rates ranging from 9% in patients ages 50 and older who have undergone elective noncardiac surgery3 to nearly 18% in patients over age 65 who have undergone emergency surgery4 and as high as 87% among el-derly patients in ICUs.5 Because postoperative de-lirium is associated with extended lengths of stay, higher patient care costs, increased morbidity with subsequent functional decline, and greater risk of death,4, 6-9 early diagnosis and resolution is likely to produce the most favorable outcomes.7, 8, 10-13

The purpose of this review is to evaluate predispos-ing and precipitating risk factors for postoperative de-lirium in elderly patients, to discuss tools used to assess preoperative risk and postoperative cognitive function

Postoperative Delirium in Elderly Patients

in this patient population, and to examine potential in-tervention strategies. Over the past 10 years, a number of predisposing clinical factors have been associated with postoperative delirium in geriatric patients, in-cluding various comorbid conditions and advanced age itself.4, 7, 8, 12, 14 Precipitating factors, defined as “nox-ious insults or hospitalization-related factors” have also been said to contribute to delirium.15 Because many risk factors are potentially modifiable, identifica-tion provides an opportunity for effective intervention.

SELECTION CRITERIATo identify studies for evaluation, I conducted a com-prehensive literature search of all English-language articles concerned with postoperative delirium in el-derly adults that were published between January 1, 2005, and December 31, 2010, and included in Ovid, MEDLINE, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL). In addition, I retrieved some nonindexed, Internet articles through a Google search. Search terms included postoperative delirium, delirium, delirium superimposed on demen-tia, surgery, advanced age, elderly, postoperative de-lirium interventions, and such suspected risk factors

2.5

OVERVIEW: Nearly 40% of all surgeries in the United States are performed on adults ages 65 and older. One of the most common surgical complications in this population is postoperative delirium, which is associated with extended lengths of stay, higher patient care costs, increased morbidity, and greater risk of death. This review evaluates risk factors for postoperative delirium in elderly patients, discusses screening and assess-ment instruments, and examines intervention strategies.

Keywords: cognitive impairment, delirium, dementia, elderly, postoperative delirium, surgery

A review of risk factors, assessment tools, and strategies to minimize this frequent surgical complication.

[email protected] AJN ▼ September 2012 ▼ Vol. 112, No. 9 39

By Paula Beth Brooks, MSN, RNFA, DNP, FNP-BC

and one tested a nonpharmacologic intervention strategy.

PREDISPOSING RISK FACTORS Advanced age was a consistent, well-established risk factor for postoperative delirium in most studies ad-dressing risk.4, 7, 8, 12, 16, 18, 21 Likewise, various comorbid-ities were associated with postoperative delirium in several studies, with some having a significant effect on mortality rate in these patients.4, 7, 8, 12, 16, 21

Independent variables. When Ansaloni and colleagues studied 351 patients over the course of 357 surgical admissions, they found that five clinical factors were significant predictors of postoperative delirium: age over 75; comorbidity (as evidenced by a Cumulative Illness Rating Scale score of 8 or higher); preoperative hyperglycemia or hypoglycemia; psycho-logical distress (as indicated by a Hospital Anxiety and Depression Scale score of 15 or more); and pre-operative cognitive impairment (as demonstrated by a Short Portable Mental Status Questionnaire score

for delirium as hypoxia, cognitive impairment, com-promised functional status, sensory impairment, sep-sis, hyperglycemia, hypoglycemia, preexisting medical conditions, physical restraint, and sleep dep rivation.

The initial literature search yielded a total of 2,204 articles, after which duplicates, review articles, and studies that did not address delirium or cognitive de-cline during the postoperative period were excluded (1,980). The remaining 224 articles were further eval-uated, and additionally excluded were any in which postoperative cognitive decline was related to alcohol, brain injury, mental disability, or other primary causes; subjects were under age 65; research was not primary (for example, meta-analyses); or investigators failed to assess either delirium risk factors or assessment methods (Figure 1). Ultimately, 12 primary research studies were included for review (Table 1).4, 7, 8, 12, 16-23

Predisposing and precipitating factors for postoper-ative delirium were investigated in seven and three of the studies reviewed, respectively (see Table 24, 7, 8,

12, 16, 18, 19, 21-23); one study compared assessment tools;

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of 7 or lower).4 In this study, the incidence of post-operative delirium was 13.2% overall and 17.9% among patients undergoing emergency surgery. Be-cause patients undergoing emergency surgery tend to be more compromised than those undergoing elec-tive surgery, the inclusion of these patients may limit the generalizability of these findings to other settings, as may the exclusion of patients with such neuropsy-chiatric disorders as speech, sensory, and gross cog-nitive impairments.

In a prospective descriptive survey of 71 patients ages 65 or older who were undergoing elective abdom-inal surgery, univariate analysis showed age over 74, longer ICU stay, longer hospital stay, greater number of postoperative complications, low preoperative cog-nitive screening test scores, and higher intraoperative American Society of Anesthesiologists scores to be significant risk factors for postoperative delirium.8 After multivariate analysis, however, only age over 74 was significant. In this study, the incidence of post-operative delirium was 24%, and the mortality rate was significantly higher in patients who developed postoperative delirium than in those who did not. The generalizability of the findings is limited by the small sample size and the fact that investigators did not control for medication use.

Inadequate nutrition and functional impairment. Of 228 patients consecutively admitted to a 650-bed teaching hospital for major abdominal surgery, Ga-nai and colleagues studied 89 they identified as be-ing at high risk for postoperative delirium based on the presence of at least three of the following previ-ously validated risk factors: severe illness, visual im-pairment, cognitive impairment, and dehydration.7 In this group, they found that poor preoperative nutri-tional status and functional impairment were signi f-icant independent predictors of postoperative delirium, which in turn was significantly associated with both a 14-day or longer increased length of stay and an in-creased risk of death. Although all patients in the study were at least 70 years of age, those who developed postoperative delirium were, on average, four years older than those who did not (81 versus 77 years), a difference that was statistically significant (P = 0.005). At 60%, the overall incidence of postoperative delir-ium in these patients was higher than expected, which the researchers suggest may be linked to suboptimal care in areas previously associated with delirium, such as prolonged bed rest, uncontrolled pain, hypoxia, poor glycemic control, and use of such medications as meperidine, hydroxyzine, benzodiazepines, diphen-hydramine, tricyclic antidepressants, muscle relaxants, and barbiturates. One major weakness in this study is that the researchers did not use a standard assess-ment tool to evaluate preoperative function and nu-tritional status but instead looked for keywords in the medical records that provided evidence of defi-cits. This may have caused them to underestimate the true incidence of preoperative functional impair-ment and malnutrition.

Preoperative cognitive function. In a small prospective study, Morimoto and colleagues dem-onstrated that cognitive function, cerebral oxygen saturation, and the incidence of postoperative delir-ium are closely related in elderly patients undergoing major abdominal surgery.21 Researchers evaluated cog nitive function in 23 patients over age 65 who were undergoing elective abdominal surgery, using

Figure 1. Study Selection and Application of Exclusion Criteria

1,980 articles excluded: duplicates, review arti-cles, articles that failed to address either delirium or cognitive decline during the postoperative period

2,204 potentially rele-vant articles identified in literature search

159 articles excluded: studies focused on pa-tients under age 65 or postoperative cognitive decline related to alco-hol, brain injury, mental disability, or other pri-mary causes

224 articles further evaluated

65 articles further evaluated

31 studies further evaluated

34 articles excluded: not primary research

19 studies excluded: did not address either delirium risk factors or assessment methods

12 studies with usable information incorporated into the evidence table


the Hasegawa dementia score (a brief, standardized dementia-screening scale) and the kana–hiroi test (an auditory verbal learning test). After excluding three pa-tients with documented cerebral pathology or base-line dementia, demonstrated by a Hasegawa dementia score below 22, they reported on 20 whose advanced age, low preoperative kana–hiroi test scores, and low intraoperative cerebral oxygen saturation (as indicated by near infrared spectroscopy) were determined to be significant risk factors for postoperative delirium. Af-ter surgery, five (25%) of the patients developed de-lirium; those who did were significantly older than those who did not (76 ± 4 years versus 68 ± 3 years), had significantly lower scores on the preoperative kana–hiroi test (16 ± 5 versus 32 ± 10), and had sig-nificantly lower baseline regional cerebral oxygen saturation levels (60% ± 5% versus 66% ± 7%). Preoperative and postoperative Hasegawa dementia scores did not differ between the two groups, and preoperative and postoperative kana–hiroi test scores did not differ significantly within either group. The study’s two greatest limitations are its small sample size and the fact that cerebral oxygen saturation was not monitored after surgery, so postoperative deficits may have gone unnoticed.

Preoperative executive dysfunction and depres-sion were independently associated with a greater in-cidence of postoperative delirium in a prospective, observational, case–control study and retrospective chart review conducted by Smith and colleagues.12 Of 998 patients undergoing major noncardiac surgery, 35 were identified as having postoperative delirium by Confusion Assessment Method (CAM) screening and retrospective chart review. Risk increased with age and comorbidity. Patients exhibiting both execu-tive dysfunction and clinically significant levels of depression were at greatest risk for developing post-operative delirium. Because patients with a history of psychiatric illness or cognitive impairment were excluded from the study, findings may fail to reflect the full impact of depression or executive dysfunction on risk of postoperative delirium.

Bellelli and colleagues investigated the relationship between delirium superimposed on dementia, which is highly prevalent among hospitalized geriatric pa-tients, and associated mortality.16 From 1,278 patients ages 65 and older who were consecutively admitted to a rehabilitation unit following surgery or other events, the researchers selected four groups of 47 each—patients with delirium superimposed on de-mentia, patients with delirium alone, patients with dementia alone, and patients with neither delirium nor dementia—which were matched for age, sex, and reason for admission. In patients with delirium super-imposed on dementia, 12-month survival after dis-charge was significantly lower than in the other three groups—12 patients died, compared with five in the delirium-alone group, five in the dementia-alone

group, and four in the neither-delirium-nor-dementia group. Because the study was conducted in a rehabil-itation unit, however, its generalizability to other clini-cal settings may be limited.

Inflammatory markers. Lemstra and colleagues found no relationship between preoperative circu-lating inflammatory markers and delirium in their study of 68 elderly patients admitted for hip surgery, 18 of whom developed postoperative delirium. They suggest that, to determine whether rising cytokine levels are in response to an injury or are contributing to it, further research should be based on sequential cytokine measurements, taken at several time points.18

PRECIPITATING FACTORS Most researchers agree that a combination of predis-posing and precipitating factors influence the devel-opment of postoperative delirium in elderly patients.

Aspects of pain management. Both analgesia and postoperative pain have been correlated with the development of postoperative delirium.19, 22 One study that evaluated the relationship between pain management and delirium in hospitalized elderly pa-tients showed that hearing deficits may put patients at risk for poor pain management and, therefore, de-lirium.22 In their retrospective medical record review involving 100 medical and surgical patients (mean age, 76.71 years) who developed delirium while hos-pitalized, Robinson and colleagues discovered that those with hearing deficits had received significantly less pain medication during the 24 hours preceding delirium onset than those who had other risk factors for delirium (P = 0.023). The authors suggest that hearing deficits in elderly patients contribute to poor communication between patient and caregiver and stress the importance of using assistive devices to communicate with such patients.

Moreover, among all patients, the researchers found a significant correlation between the time from admission or surgery to delirium onset and the per-centage of pain medication received, with patients who experienced delirium having received only a small proportion of their ordered pain medication in the 24 hours before delirium onset. Those who re-ceived greater amounts of pain medication had a later occurrence of delirium. Physician notes showed that, in many cases, delirium was attributed to opioids; but this was without basis, since the amount of pain med-ication the patient received was not determined be-fore discontinuation and, as the authors point out,

Hearing deficits may put patients at

risk for poor pain management

and, therefore, delirium.


Stud

yFo

cus

Stud

y D

esig

n Su

bjec

t Dat

aFi

ndin

gs a

nd L

imita

tions

Pred

ispos

ing

risk

fact

ors (

7)

Ansa

loni

L, e

t al.

Br J

Surg

201

0;97

(2):

273-

80.4

The

inci

denc

e of

PO

D

amon

g el

derly

surg

ical

pa

tient

s, as

soci

ated

ris

k fa

ctor

s, an

d im

pact

on

hos

pita

l sta

y an

d m

orta

lity

Pros

pect

ive,

ob

serv

atio

nal,

case

–con

trol

st

udy

351

patie

nts/

357

adm

issio

ns

Patie

nts w

ith P

OD

(n =

47)

(13%

) Se

x ra

tio (M

:F):

23:2

4

Mea

n ag

e (y

ears

): 80

Patie

nts w

ithou

t PO

D

(n =

310

) (87

%)

Sex

ratio

(M:F

): 12

3:18

7

Mea

n ag

e (y

ears

): 75

Age

over

75,

com

orbi

dity

, pre

oper

ativ

e co

gniti

ve im

pairm

ent,

psyc

holo

gica

l dist

ress

, and

abn

orm

al g

lyce

mic

con

trol

wer

e al

l sig

nific

ant,

inde

pend

ent p

redi

ctor

s of P

OD

. Ove

rall

inci

-de

nce

of P

OD

was

13.

2%. I

ncid

ence

was

sign

ifica

ntly

hig

her

in p

atie

nts u

nder

goin

g em

erge

nt su

rger

y (1

7.9%

) tha

n in

th

ose

unde

rgoi

ng e

lect

ive

surg

ery

(6.7

%).

Lim

itatio

ns: I

nclu

sion

of p

atie

nts u

nder

goin

g em

erge

ncy

surg

ery

and

excl

usio

n of

pat

ient

s with

neu

rops

ychi

atric

di

sord

ers m

ay li

mit

gene

raliz

abili

ty o

f fin

ding

s.

Belle

lli G

, et a

l. J

Ger

onto

l A B

iol S

ci

Med

Sci

200

7;62

(11)

: 13

06-9

.16

The

rela

tions

hip

betw

een

delir

ium

su

perim

pose

d on

de

men

tia a

mon

g ho

spita

lized

ger

iatr

ic

patie

nts,

follo

win

g su

rger

y or

oth

er

even

ts, a

nd a

ssoc

iate

d 12

-mon

th m

orta

lity

Pros

pect

ive,

ob

serv

atio

nal,

case

–con

trol

st

udy

188

of 1

,278

pat

ient

s, ag

es ≥

65,

cons

ecut

ivel

y ad

mitt

ed to

a

reha

bilit

atio

n un

it

Nei

ther

del

irium

nor

dem

entia

(n

= 4

7)

Mea

n ag

e (y

ears

): 79

.3

Wom

en: 7

8%

Dem

entia

(n =

47)

M

ean

age

(yea

rs):

79.6

W

omen

: 78%

Del

irium

(n =

47)

M

ean

age

(yea

rs):

79.4

W

omen

: 78%

Del

irium

and

dem

entia

(n =

47)

M

ean

age

(yea

rs):

80.1

W

omen

: 78%

In th

e 12

mon

ths a

fter d

ischa

rge,

mor

talit

y w

as si

gnifi

cant

ly

high

er—

mor

e th

an tw

ice

as h

igh—

in p

atie

nts w

ith d

eliri

um

supe

rimpo

sed

on d

emen

tia th

an it

was

in p

atie

nts w

ith

neith

er d

eliri

um n

or d

emen

tia, p

atie

nts w

ith d

emen

tia

alon

e, o

r pat

ient

s with

del

irium

alo

ne.

Lim

itatio

ns: R

ehab

ilita

tion

unit

sett

ing

limits

gen

eral

izab

ility

of

find

ings

to o

ther

clin

ical

sett

ings

.

Gan

ai S

, et a

l. Arc

h Su

rg 2

007;

142(

11):

1072

-8.7

The

corr

elat

ion

betw

een

clin

ical

fa

ctor

s ass

ocia

ted

with

PO

D in

ger

iatr

ic

patie

nts u

nder

goin

g ab

dom

inal

surg

ery

and

adve

rse

outc

omes

Retr

ospe

ctiv

e ca

se se

ries

stud

y

89 o

f 228

pat

ient

s adm

itted

for

abdo

min

al su

rger

y an

d id

enti-

fied

as b

eing

at h

igh

risk

for

POD

Age

(yea

rs):

≥ 70

Men

: 42

(47%

)

Engl

ish sp

eaki

ng: 8

7 (9

8%)

Emer

genc

y ad

miss

ion:

72

(81%

)

Amon

g pa

tient

s with

such

reco

gniz

ed ri

sk fa

ctor

s for

PO

D

as se

vere

illne

ss, v

isual

impa

irmen

t, co

gniti

ve im

pairm

ent,

or

dehy

drat

ion,

poo

r pre

oper

ativ

e nu

triti

onal

stat

us a

nd fu

nc-

tiona

l impa

irmen

t wer

e sig

nific

ant,

inde

pend

ent p

redi

ctor

s of

POD,

whi

ch w

as a

ssoc

iate

d w

ith a

14-

day

or lo

nger

incr

ease

d le

ngth

of s

tay

and

an in

crea

sed

risk

of d

eath

. The

mea

n ag

e of

th

e pa

tient

s who

dev

elop

ed P

OD

was

sign

ifica

ntly

gre

ater

than

th

at o

f the

pat

ient

s who

did

not

(81

vers

us 7

7 ye

ars;

P =

0.00

5).

Lim

itatio

ns: N

o st

anda

rd a

sses

smen

t too

l was

use

d to

eva

lu-

ate

preo

pera

tive

func

tion

and

nutr

ition

al st

atus

, so

defic

its

may

hav

e be

en u

nder

estim

ated

.

Tabl

e 1.

Res

earc

h St

udie

s Rev

iew

ed


Koeb

rugg

e B,

et a

l. D

ig S

urg

2009

;26(

1):

63-8

.8

The

inci

denc

e, ri

sk

fact

ors,

and

outc

omes

as

soci

ated

with

PO

D

in e

lder

ly p

atie

nts

unde

rgoi

ng e

lect

ive

abdo

min

al su

rger

y on

a

unit

with

a h

igh

stan

dard

of d

eliri

um

care

Pros

pect

ive

desc

riptiv

e su

rvey

71 p

atie

nts

Patie

nts w

ith P

OD

(n =

17)

M

en: 1

0 (5

9%)

Wom

en: 7

(41%

) M

ean

age

(yea

rs):

76.1

± 5

.8

Age

≥75:

11

(65%

)

Patie

nts w

ithou

t PO

D (n

= 5

4)

Men

: 27

(50%

) W

omen

: 27

(50%

) M

ean

age

(yea

rs):

73.4

± 4

.9

Age

≥75:

19

(35%

)

Mor

talit

y ra

te w

as h

ighe

r in

patie

nts w

ho d

evel

oped

del

ir-iu

m a

fter u

nder

goin

g el

ectiv

e ab

dom

inal

surg

ery

than

in

thos

e w

ho d

id n

ot. U

niva

riate

ana

lysis

show

ed si

gnifi

cant

ris

k fa

ctor

s for

del

irium

incl

uded

age

ove

r 74,

low

pre

oper

a-tiv

e CS

T sc

ore,

hig

h in

traop

erat

ive

ASA

scor

e, lo

nger

ICU

stay

, lo

nger

hos

pita

l sta

y, a

nd g

reat

er n

umbe

r of p

osto

pe ra

tive

com

plic

atio

ns. A

fter m

ultiv

aria

te a

naly

sis, o

nly

age

over

74

was

sign

ifica

nt.

Lim

itatio

ns: T

he sm

all s

ampl

e siz

e lim

its th

e ge

nera

lizab

ility

of

find

ings

. The

inve

stig

ator

s did

not

cons

ider

med

icat

ion

use.

Lem

stra

AW

, et a

l. Int

J G

eria

tr P

sych

iatr

y 20

08;2

3(9)

:943

-8.18

The

rela

tions

hip

betw

een

preo

pera

tive

circ

ulat

ing

cyto

kine

le

vels

and

delir

ium

in

eld

erly

pat

ient

s un

derg

oing

hip

su

rger

y, w

ho a

re

othe

rwise

hea

lthy

Pros

pect

ive,

ne

sted

, cas

e–co

ntro

l stu

dy

68 p

atie

nts,

18 w

ith d

eliri

um

and

50 c

ontr

ols,

mat

ched

for

age

and

base

line

APAC

HE

II sc

ores

Patie

nts w

ith P

OD

(n =

18)

M

ean

age

(rang

e) in

yea

rs:

80 (7

1–91

) Se

x ra

tio (M

:F):

8:10

Patie

nts w

ithou

t PO

D (n

= 5

0)

Mea

n ag

e (ra

nge)

in y

ears

: 78

.5 (7

1–88

) Se

x ra

tio (M

:F):

13:3

7

Inve

stig

ator

s fou

nd n

o re

latio

nshi

p be

twee

n pr

eope

rativ

e le

vels

of c

ircul

atin

g cy

toki

nes a

nd P

OD

in e

lder

ly p

atie

nts

who

wer

e fre

e fro

m a

cute

or s

ever

e di

seas

e.

Lim

itatio

ns: B

ecau

se o

f the

smal

l num

ber o

f pat

ient

s in

the

stud

y, in

vest

igat

ors m

ay h

ave

over

look

ed a

smal

l inc

reas

e in

del

irium

risk

ass

ocia

ted

with

hig

her l

evel

s of c

ytok

ines

.

Mor

imot

o Y,

et a

l. J

Anes

th 2

009;

23(1

): 51

-6.21

The

rela

tions

hip

betw

een

intr

aope

r-at

ive

cere

bral

oxy

gen

satu

ratio

n, c

ogni

tive

func

tion,

and

inci

denc

e of

PO

D in

eld

erly

pa

tient

s und

ergo

ing

maj

or a

bdom

inal

su

rger

y

Pros

pect

ive,

ob

serv

atio

nal,

case

–con

trol

st

udy

20 p

atie

nts

Patie

nts w

ith P

OD

(n =

5)

Mea

n ag

e (y

ears

): 76

± 4

Se

x ra

tio (M

:F):

4:1

Patie

nts w

ithou

t PO

D (n

= 1

5)

Mea

n ag

e (y

ears

): 68

± 3

Se

x ra

tio (M

:F):

10:5

Patie

nts w

ho d

evel

oped

PO

D w

ere

signi

fican

tly o

lder

, had

sig

nific

antly

low

er b

asel

ine

intr

aope

rativ

e re

gion

al c

ereb

ral

oxyg

en sa

tura

tion

leve

ls, a

nd h

ad si

gnifi

cant

ly lo

wer

pre

op-

erat

ive

kana

–hiro

i tes

t sco

res,

indi

catin

g gr

eate

r cog

nitiv

e dy

sfun

ctio

n.

Lim

itatio

ns: T

he st

udy’s

smal

l sam

ple

size

limits

the

gene

ral-

izab

ility

of f

indi

ngs.

Cere

bral

oxy

gen

satu

ratio

n w

as m

oni-

tore

d on

ly d

urin

g su

rger

y, so

pos

tope

rativ

e de

ficits

may

ha

ve g

one

unno

ticed

.


Stud

yFo

cus

Stud

y D

esig

n Su

bjec

t Dat

aFi

ndin

gs a

nd L

imita

tions

Smith

PJ,

et a

l. An

esth

esio

logy

2009

;110

(4):7

81-7

.12

The

asso

ciat

ion

betw

een

preo

pera

tive

exec

utiv

e fu

nctio

n,

depr

essiv

e sy

mpt

oms,

and

esta

blish

ed c

linic

al

pred

icto

rs o

f PO

D

amon

g pa

tient

s und

er-

goin

g m

ajor

non

car-

diac

surg

ery

Pros

pect

ive,

ob

serv

atio

nal,

case

–con

trol

st

udy

and

ret-

rosp

ectiv

e ch

art r

evie

w

998

patie

nts

Patie

nts w

ith P

OD

(n =

35)

M

ean

age

(yea

rs):

63

.9 ±

15.

5 M

ean

educ

atio

n le

vel (

year

s):

13 ±

3.1

Patie

nts w

ithou

t PO

D (n

= 9

61)

Mea

n ag

e (y

ears

):

50.5

± 1

6.8

Mea

n ed

ucat

ion

leve

l (ye

ars)

: 13

.5 ±

2.6

Preo

pera

tive

exec

utiv

e dy

sfun

ctio

n an

d de

pres

sive

sym

p-to

ms w

ere

pred

ictiv

e of

PO

D a

mon

g no

ncar

diac

surg

ical

pa

tient

s, w

ith p

erfo

rman

ce o

n ex

ecut

ive

task

s of g

reat

er

com

plex

ity m

ore

stro

ngly

ass

ocia

ted

with

PO

D th

an

perfo

rman

ce o

n te

sts o

f bas

ic se

quen

cing

.

Lim

itatio

ns: P

atie

nts w

ith a

hist

ory

of p

sych

iatr

ic il

lnes

s or

cogn

itive

impa

irmen

t wer

e ex

clud

ed, p

ossib

ly u

nder

pow

er-

ing

the

anal

ysis

of d

epre

ssiv

e sy

mpt

oms a

nd re

stric

ting

the

rang

e of

the

exec

utiv

e fu

nctio

n va

riabl

e.

Prec

ipita

ting

fact

ors (

3)

Leun

g JM

, et a

l. An

esth

esio

logy

20

09;1

11(3

):625

-31.

19

Feas

ibili

ty o

f PCA

use

in

pat

ient

s with

PO

DN

este

d co

hort

st

udy

335

patie

nts

Patie

nts w

ith P

OD

(n =

185

) M

ean

age

(yea

rs):

74

.13

± 6.

36

Sex

ratio

(M:F

): 70

:115

Patie

nts w

ithou

t PO

D (n

= 1

50)

Mea

n ag

e (y

ears

):

72.8

2 ±

5.87

Se

x ra

tio (M

:F):

80:7

0

POD

did

not

lim

it th

e us

e of

PCA

. Pat

ient

s dia

gnos

ed w

ith

POD

use

d as

muc

h or

mor

e PC

A th

an th

ose

with

out.

Lim

itatio

ns: B

ecau

se th

e st

udy

eval

uate

d on

ly th

e ea

rly

post

oper

ativ

e pe

riod

(less

than

48

hour

s fol

low

ing

surg

ery)

, so

me

case

s of l

ate-

onse

t PO

D m

ay h

ave

been

miss

ed.

Robi

nson

S, e

t al.

Pain

Man

ag N

urs

2008

;9(2

):66-

72.22

The

asso

ciat

ion

betw

een

pain

and

de

liriu

m in

med

ical

an

d su

rgic

al p

atie

nts

Retr

ospe

ctiv

e m

edic

al re

cord

re

view

100

patie

nts

Mea

n ag

e (ra

nge)

in y

ears

: 76

.71

(41–

90)

Men

: 62

Wom

en: 3

8

Ther

e w

as a

sign

ifica

nt co

rrela

tion

betw

een

the

time

from

ad-

miss

ion

or su

rger

y to

del

irium

ons

et a

nd th

e pe

rcen

tage

of

pain

med

icat

ion

rece

ived

, with

pat

ient

s hav

ing

rece

ived

onl

y a

smal

l pro

port

ion

of th

eir a

llow

ed p

ain

med

icat

ion

befo

re

delir

ium

ons

et. E

lder

ly p

atie

nts w

ith h

earin

g lo

ss re

ceiv

ed si

g-ni

fican

tly le

ss p

ain

med

icat

ion

durin

g th

e 24

hou

rs p

rece

ding

de

liriu

m o

nset

than

thos

e w

ith o

ther

risk

fact

ors f

or d

eliri

um.

Find

ings

sugg

est t

hat u

nman

aged

pai

n m

ay b

e a

prec

ipita

t-in

g fa

ctor

for d

eliri

um in

med

ical

and

surg

ical

pat

ient

s and

th

at h

earin

g de

ficits

in e

lder

ly p

atie

nts m

ay c

ontr

ibut

e to

po

or c

omm

unic

atio

n be

twee

n pa

tient

and

car

egiv

er, r

esul

t-in

g in

poo

r pai

n m

anag

emen

t and

incr

easin

g th

e ris

k of

PO

D.

Lim

itatio

ns: B

ecau

se th

is w

as a

retr

ospe

ctiv

e m

edic

al re

cord

re

view

, dat

a w

ere

depe

nden

t on

phys

icia

n re

cogn

ition

and

do

cum

enta

tion

of d

eliri

um.

Tabl

e 1.

Con

tinue

d


Sieb

er F

E, e

t al. M

ayo

Clin

Pro

c 201

0;85

(1):

18-2

6.23

The

effe

ct o

f int

raop

er-

ativ

e se

datio

n de

pth

durin

g sp

inal

ane

sthe

-sia

for h

ip fr

actu

re re

-pa

ir on

pre

vale

nce

of

POD

in e

lder

ly p

atie

nts

Dou

ble-

blin

d,

rand

omiz

ed

cont

rolle

d tr

ial

114

patie

nts

Patie

nts g

iven

dee

p se

datio

n (n

= 5

7)

Mea

n ag

e (y

ears

): 8

1.8

± 6.

7

Sex

ratio

(M:F

): 14

:43

Patie

nts g

iven

ligh

t sed

atio

n (n

= 5

7)

Mea

n ag

e (y

ears

):

81.2

± 7

.6

Sex

ratio

(M:F

): 17

:40

The

use

of li

ght p

ropo

fol s

edat

ion

halv

ed th

e pr

eval

ence

of

PO

D c

ompa

red

with

dee

p se

datio

n (1

9% v

ersu

s 40%

). Th

e m

ean

num

ber o

f day

s of d

eliri

um d

urin

g ho

spita

lizat

ion

was

sign

ifica

ntly

few

er in

the

light

seda

tion

grou

p th

an in

th

e de

ep se

datio

n gr

oup

(0.5

±1.

5 da

ys v

ersu

s 1.4

± 4

day

s).

Lim

itatio

ns: B

ecau

se p

atie

nts w

ith se

vere

cog

nitiv

e im

pair-

men

t (M

ini-M

enta

l Sta

te E

xam

inat

ion

scor

es b

elow

15)

w

ere

excl

uded

, gen

eral

izab

ility

of t

he fi

ndin

gs is

lim

ited.

Early

iden

tific

atio

n (1

)

Luet

z A,

et a

l. Crit

Ca

re M

ed 2

010;

38(2

): 40

9-18

.20

The

com

para

tive

val-

idity

and

relia

bilit

y of

th

ree

tool

s for

det

ect-

ing

and

asse

ssin

g de

-lir

ium

in th

e IC

U: t

he

CAM

-ICU

, the

Nu-

DES

C,

and

the

DD

S

Pros

pect

ive

coho

rt st

udy

156

patie

nts c

onse

cutiv

ely

ad-

mitt

ed to

a G

erm

an su

rgic

al IC

U

Leng

th o

f sta

y: ≥

24

hour

s

Age

(yea

rs):

≥ 60

Beca

use

of it

s hig

h sp

ecifi

city

, the

CAM

-ICU

was

det

erm

ined

th

e be

st to

ol fo

r ide

ntify

ing

delir

ium

in th

e IC

U. B

oth

the

CAM

-ICU

and

the

Nu-

DES

C pe

rform

ed b

ette

r tha

n th

e D

DS.

Lim

itatio

ns: T

o m

inim

ize

bias

, ass

essm

ents

wer

e pe

rform

ed

in th

e sa

me

orde

r, st

artin

g w

ith th

e D

DS,

whi

ch m

ay h

ave

influ

ence

d th

e re

sults

of s

ubse

quen

t tes

ts. I

nter

rate

r rel

iabi

l-ity

was

bas

ed o

n a

smal

l num

ber o

f pai

red

obse

rvat

ions

.

Inte

rven

tion

(1)

Kola

now

ski A

M, e

t al.

Res G

eron

tol N

urs

2011

;4(3

):161

-7.17

Effe

ct o

f cog

nitiv

e st

im-

ulat

ion

inte

rven

tion

on

seve

rity

and

dura

tion

of

delir

ium

in p

osta

cute

ca

re se

ttin

gs a

nd a

sso-

ciat

ed fu

nctio

nal l

oss

Rand

omiz

ed

cont

rolle

d pi

lot

stud

y

16 p

atie

nts w

ith d

eliri

um su

per-

impo

sed

on d

emen

tia, h

ospi

tal-

ized

on

a m

edic

al–s

urgi

cal u

nit

Inte

rven

tion

grou

p (n

= 1

1)

Mea

n ag

e (y

ears

): 88

.4 ±

4.9

W

omen

: 54.

5%

Cont

rol g

roup

(n =

5)

Mea

n ag

e (y

ears

): 82

.4 ±

2.9

W

omen

: 62.

5%

Patie

nts w

ith d

eliri

um su

perim

pose

d on

dem

entia

who

wer

e en

gage

d in

cog

nitiv

ely

stim

ulat

ing

activ

ities

for 3

0 m

inut

es

per d

ay (t

he in

terv

entio

n gr

oup)

dem

onst

rate

d sig

nific

antly

le

ss d

eclin

e in

phy

sical

func

tion

and

men

tal s

tatu

s ove

r tim

e co

mpa

red

with

thos

e gi

ven

usua

l car

e (th

e co

ntro

l gro

up).

The

inte

rven

tion

grou

p ha

d fe

wer

day

s with

del

irium

, less

se

vere

del

irium

, and

hig

her a

tten

tion

scor

es.

Lim

itatio

ns: T

he st

udy’s

smal

l sam

ple

size

mad

e it

diffi

cult

to

dem

onst

rate

stat

istic

al si

gnifi

canc

e in

mos

t are

as e

valu

ated

.

APA

CHE

II =

Acut

e Ph

ysio

logy

and

Chr

onic

Hea

lth E

valu

atio

n II;

ASA

= A

mer

ican

Soc

iety

of A

nest

hesi

olog

ists

; CA

M =

Con

fusi

on A

sses

smen

t Met

hod;

CST

= c

ogni

tive

scre

enin

g te

st; D

DS

= D

eliri

um D

etec

tion

Scor

e;

Nu-

DES

C =

Nur

sing

Del

irium

Scr

eeni

ng S

cale

; PCA

= p

atie

nt-c

ontr

olle

d an

alge

sia;

PO

D =

pos

tope

rativ

e de

liriu

m.


previous studies demonstrate no association between most opioids and delirium. In nine cases, however, pa-tients were receiving drugs whose cumulative effect is associated with delirium in older patients: propoxy-phene and meperidine, which were given to eight pa-tients and one patient, respectively.

The study suggests that in patients at risk for de-veloping delirium, both unmanaged pain and some specific pain medications may be precipitating fac-tors. Study limitations include its retrospective de-sign, which depends heavily on accurate clinician recognition and documentation of delirium, and cli-nicians’ failure to use a valid and reliable instrument to assess delirium.

Leung and colleagues also investigated pain and postoperative delirium, specifically focusing on whether it’s feasible for patients with postoperative delirium to use patient-controlled analgesia (PCA). In a nested cohort study of 335 patients ages 65 and older who underwent noncardiac surgery, the authors determined that postoperative delirium did not limit the use of PCA.19 Patients with postoperative delirium had significantly higher visual analog scale scores for pain following surgery, but not because they were unable to use PCA. In fact, they used PCA as much or more than nondelirious patients. Although the in-vestigators reached no conclusion about the role of causality in the relationship between postoperative delirium and pain, their findings suggest that pain could be more effectively managed in elderly patients at risk for postoperative delirium. Because this study evaluated only the early postoperative period (less than 48 hours following surgery), some cases of late-onset postoperative delirium may have been missed.

Some sedation techniques have been proposed as causative factors in the development of postoperative delirium in elderly patients. In a double-blind, ran-domized controlled trial by Sieber and colleagues, 114 patients ages 65 or older, with no preexisting cognitive impairment, underwent hip fracture repair under spinal anesthesia with propofol sedation.23 Pa-tients were randomly assigned to receive either deep or light sedation, and researchers used electroenceph-alography with bispectral index to titrate sedation depth. Researchers found that the use of light pro-pofol sedation halved the frequency of postoperative delirium when compared with deep sedation (19% versus 40%). Furthermore, the mean number of days of delirium during hospitalization was significantly

fewer in the light sedation group than in the deep sedation group (0.5 ± 1.5 days versus 1.4 ± 4 days). Although the total dose of pro pofol was significantly higher in the deep sedation group, dose alone did not predict the occurrence of postoperative delirium. The most important predictor in this patient popula-tion was the depth of sedation. These findings sug-gest that limiting the depth of sedation in some spinal anesthesia procedures may be an effective strategy for preventing postoperative delirium in elderly pa-tients. The generalizability of these results is limited to patients with only moderate or minimal dementia, because patients with severe cognitive impairment (Mini-Mental State Examination scores below 15) were excluded.

EARLY IDENTIFICATIONLuetz and colleagues compared several delirium as-sessment tools in a prospective cohort study that in-cluded 156 patients ages 60 or older who spent at least 24 hours in a German surgical ICU.20 The re-searchers concluded that the CAM-ICU and the Nursing Delirium Screening Scale (Nu-DESC) had comparable sensitivities in this population (81% and 83%, respectively). They found, however, that the specificity of the CAM-ICU was much higher than that of the Nu-DESC (95% versus 81%), and both tests performed better than the Delirium Detection Score (DDS). From this study, the researchers con-cluded that, because of its high specificity, the CAM-ICU is the best tool to use in an elderly surgical ICU population. A major limitation of this study is the subjects’ variable lengths of ICU stay, which ranged from 24 hours to 21 days and may have biased the results. In addition, interrater reliability was deter-mined on the basis of only 37 paired observations. Finally, although investigators attempted to minimize bias by consistently performing assessments in the same order, starting with the DDS, it’s possible that earlier assessments influenced the results of subse-quent assessments.

INTERVENTIONIn a small blinded, controlled trial, Kolanowski and colleagues randomly assigned 16 elderly medical–surgical patients who had been admitted to a postacute care rehabilitation center with delir-ium superimposed on dementia to either a non-pharmacologic intervention group that engaged in cognitively stimulating activities for 30 minutes per day (n = 11) or a control group that received usual care (n = 5).17 When compared with the intervention group, the control group had a significantly greater decline in physical function and mental status over time. Although the study’s small sample size made it difficult to demonstrate statistical significance, pa-tients in the intervention group had fewer days with delirium, less severe delirium, and higher attention

Even among elderly patients, risk of

postoperative delirium increased

significantly with age.


scores than patients in the control group, with differ-ences approaching significance in all three areas.

DISCUSSIONPredicting postoperative delirium. In the studies re-viewed, advanced age, long recognized as a risk fac-tor for postoperative delirium, was consistently found to be an important predictor; even among elderly pa-tients, risk increased significantly with age.4, 7, 8, 12, 21 Cognitive impairment, psychological distress, post-operative complications, glycemic abnormalities, mal-nutrition, and functional impairment predisposed to postoperative delirium in several studies—with inad-equate nutrition, functional impairment, and demen-tia significantly elevating risk of death.4, 7, 8, 12, 16, 18, 21 Although the causal relationship between pain and postoperative delirium isn’t clear, postoperative pain scores were higher among patients with delirium in one study,19 while pain medication appeared to delay onset of postadmission and postoperative delirium in another.22 Both of these studies suggest that pain management is often inadequate in elderly patients at risk for postoperative delirium. Depth of sedation was significantly associated with postoperative delir-ium, with deep sedation doubling its prevalence and significantly increasing the duration of delirium dur-ing hospitalization.23

Findings on cognitive impairment in postoperative patients are consistent with studies of hospitalized ge-riatric patients in general medical units. In a descrip-tive study evaluating patterns associated with delirium in 104 patients, researchers found that the prevalence of delirium among geriatric patients newly admitted to an acute care hospital increased significantly with severity of prior cognitive impairment.24 Among pa-tients with mild, moderate, and severe prior cognitive impairment, prevalence of delirium, as assessed by the CAM, was 50% (24 of 48), 82% (23 of 28), and 86% (24 of 28), respectively. Degree of prior cognitive impairment significantly affected only one symptom of delirium, disorganized thinking, which occurred in 58% of patients whose prior cognitive impairment was mild and in 92% of those whose prior cognitive impairment was severe. The study authors propose training programs to prepare nurses to recognize sub-tle changes in mental status that may signify the de-velopment of delirium among elderly patients with a history of prior cognitive impairment.

The role of inflammatory markers in delirium has not been studied extensively. In this review, based on one study of 68 geriatric patients,18 inflammatory markers were found to have no association with post-operative delirium—a finding that is inconsistent with that of an earlier study of delirium in elderly patients hospitalized for general medical conditions, conducted by de Rooij and colleagues.25 In that study, 64 (34.6%) of 185 patients, ages 65 and older, developed delirium within 48 hours of hospital admission. Significantly

more patients without delirium than with delirium had interleukin-6 and interleukin-8 levels below the detection limit (69% versus 47%, and 78% versus 55%, respectively). After adjusting for infection, age, and cognitive impairment, these differences remained significant. The authors acknowledge, however, that their study may be limited by the small number of pa-tients with detectable cytokine levels and by the fact that cytokines were measured in peripherally sampled blood, most of which was obtained three days after admission and therefore may not accurately reflect the inflammatory processes occurring in the brain during delirium.

For patients in a general medical service, Inouye and Charpentier found five variables to be predictive of delirium during hospitalization: use of physical re-straints, malnutrition, the addition of more than three medications, use of a bladder catheter, and any iatro-genic event (such as a cardiopulmonary complication, hospital-acquired infection or injury, medication- related or procedural complication, pressure sore, or fecal impaction).15 With the exception of malnutri-tion,7 the studies of postoperative delirium reviewed here did not investigate these risk factors.

Table 2. Factors Contributing to Postoperative Delirium in Elderly Surgical Patients 4, 7, 8, 12, 16, 18, 19, 21-23

Predisposing factors (clinical factors present before surgery)

Precipitating factors (hospitalization-related factors)

• Abnormal glycemic control (hyperglycemia or hypoglycemia) • Analgesia

• Advanced age • Medications

• Analgesia • Physical restraints

• Anxiety • Postoperative pain

• Cognitive impairment • Sedation

• Dementia • Sleep deprivation

• Depression • Surgery

• Hearing deficits • Unmanaged pain

• Hypoxia

• Inflammatory processes (acute medical illness or infection)

• Medical comorbidities

• Medications

• Poor functional state

• Poor nutritional state (for example, hypoalbuminemia)

• Prolonged bed rest

• Sedation


Assessing delirium. The majority of studies in this review used the CAM to identify delirium in surgical patients.4, 12, 16-19, 23 Available in both nine- and four-item forms, the CAM has been validated for use by non-psychiatric clinicians.26 A nonverbal form of this tool, the CAM-ICU, was found to be valid and reliable in detecting delirium in patients who are mechanically ventilated.27 In this 2001 prospective cohort study of medical and coronary ICU patients, two critical care study nurses used the test to independently rate 96 mechanically ventilated patients throughout their ICU stay, and delirium experts performed indepen-dent evaluations based on the Diagnostic and Statis-tical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. Between nurses and delirium ex-perts, a total of 471 paired daily evaluations were col-lected. The CAM-ICU was shown to have sensitivity ratings of 100% (nurse 1) and 93.5% (nurse 2), spec-ificity ratings of 97.8% (nurse 1) and 100% (nurse 2), and excellent interrater reliability (κ = 0.96). Although authors of the validation study noted that the general-izability of their findings to patient populations with a lower prevalence of delirium may be limited, in the one study reviewed here that compared delirium as-sessment tools, the CAM-ICU was found to be the best tool for detecting delirium in elderly surgical ICU patients, being superior to both the Nu-DESC and the DDS.20

Preventing decline. The one intervention study in this review found that daily cognitive stimulation could reduce the severity and duration of postopera-tive delirium in patients with dementia.17 Similarly, evidence-based research has demonstrated that com-prehensive programs, such as the Hospital Elder Life Program (HELP), may be effective in preventing delir-ium and preserving independent functioning in older hospitalized patients.28 The program’s interdisciplin-ary staff and trained volunteers work within existing hospital units to identify patients at risk for cognitive and functional decline during the preoperative and early postoperative periods. Interventions focus on orientation and assistance with meals and ambula-tion; activities encourage socialization and cognitive stimulation.29 Rubin and colleagues found that HELP could reduce the incidence of delirium, while lower-ing patient care costs. In the seven years following implementation of the program in a 500-bed commu-nity teaching hospital, the rate of delirium dropped from 41% to 18%; length of stay was reduced by

1.8 days in patients with delirium and by 0.7 days in patients without delirium; hospital costs were signifi-cantly lowered by an estimated $7.3 million per year; and satisfaction improved among patients, families, and nursing staff.28

Neitzel and colleagues developed an approach to preventing and managing delirium in orthopedic pa-tients, which involved the use of a multidisciplinary team (consisting of physicians, nurses, pharmacists, and a quality specialist) and a set of evidence-based orders that limited the use of indwelling catheters, set up patient routines, promoted adequate rest, en-couraged pharmacist review of medications, and in-corporated such integrative therapies as therapeutic touch and music.30 Over the course of a four-week trial within a tertiary care hospital, the program re-duced the proportion of patients with NEECHAM Confusion Assessment Scale scores below 20 by nearly 9% compared with the proportion of such patients identified the year before program implementation.

IMPLICATIONS FOR PRACTICE Multiple studies have demonstrated that postopera-tive delirium in elderly surgical patients is multifac-torial in etiology.7, 8, 11, 12, 19, 21, 31 Both predisposing and precipitating factors can elevate the risk,4, 8, 14 and many of these—such as poor glycemic control, inadequate nutrition, poor pain management, medication use, and depth of intraoperative sedation—are modifiable. Once a patient is identified as being at risk, a multi-factorial prevention program needs to be initiated. Prevention is the goal, and identifying risk is key to prevention.

To determine risk, use an assessment tool, such as the CAM or CAM-ICU, or apply criteria specified in the DSM-IV to establish the patient’s baseline men-tal status.20, 27, 32, 33 (To learn more about using the CAM, see “How to Try This: Detecting Delirium” at http://bit.ly/MODqAU and the demonstration video at http://bit.ly/MnX0W8.) Researchers concur that a multidisciplinary team that addresses both preoper-ative and postoperative risk factors is generally most effective in preventing postoperative delirium in el-derly patients.34, 35 Some researchers suggest that sur-gical teams for older patients should include a geriatric nursing specialist34 and that elderly surgical patients should be cared for in specialized geriatric units.36

The Nurses Improving Care for Healthsystem El-ders (NICHE) program, developed at New York Uni-versity in 1992, can assist hospital staff in caring for geriatric surgical patients.37 This program employs ge-riatric advanced practice nurses to train RNs to pro-vide appropriate care for elderly patients and helps facilities adjust care practices to better meet their needs.

Advances in anesthesia, critical care, and surgical techniques have made geriatric surgery reasonably safe. Despite these improvements, elderly patients

A new diagnosis of delirium after

hospitalization increases a patient’s

risk of falling sixfold.


continue to face a high risk of postoperative delirium. A new diagnosis of delirium after hospitalization in-creases a patient’s risk of falling sixfold.38 This is a sig-nificant concern since falls, according to the National Institutes of Health, are the leading cause of injury, loss of independence, and death nationwide for those over 65 years of age.39

Nurses are in a unique position to implement and coordinate services for their patients. Postoperative care needs to focus not only on cognition but also on ability to perform activities of daily living. This review suggests the benefit of nurses formally assessing el-derly patients at risk for postoperative delirium and, upon recognizing early signs, initiating intervention measures. Formal instruments for assessing delirium should be used routinely by every nurse assessing an elderly surgical patient. ▼

Paula Beth Brooks is a surgical NP at Cape Cod Hospital in Hyannis, MA. Contact author: [email protected]. The author has disclosed no potential conflicts of interest, financial or otherwise.

REFERENCES1. Centers for Disease Control and Prevention. National hospi-

tal discharge survey: procedures by selected patient character-istics. Number by procedure category and sex. 2009. http://www.cdc.gov/nchs/nhds/nhds_tables.htm#procedures.

2. Centers for Disease Control and Prevention. The state of ag-ing and health in America 2004. Washington, DC: Merck In-stitute of Aging and Health; 2004. http://www.silverbook.org/browse.php?id=21.

3. Marcantonio ER, et al. A clinical prediction rule for delirium after elective noncardiac surgery. JAMA 1994;271(2):134-9.

4. Ansaloni L, et al. Risk factors and incidence of postoperative delirium in elderly patients after elective and emergency sur-gery. Br J Surg 2010;97(2):273-80.

5. Ely EW, et al. Evaluation of delirium in critically ill patients: validation of the Confusion Assessment Method for the In-tensive Care Unit (CAM-ICU). Crit Care Med 2001;29(7): 1370-9.

6. Flinn DR, et al. Prevention, diagnosis, and management of postoperative delirium in older adults. J Am Coll Surg 2009; 209(2):261-8.

7. Ganai S, et al. Adverse outcomes of geriatric patients under-going abdominal surgery who are at high risk for delirium. Arch Surg 2007;142(11):1072-8.

8. Koebrugge B, et al. Delirium after abdominal surgery at a sur-gical ward with a high standard of delirium care: incidence, risk factors and outcomes. Dig Surg 2009;26(1):63-8.

9. Leslie DL, et al. One-year health care costs associated with delirium in the elderly population. Arch Intern Med 2008; 168(1):27-32.

10. Fong TG, et al. Delirium in elderly adults: diagnosis, preven-tion and treatment. Nat Rev Neurol 2009;5(4):210-20.

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12. Smith PJ, et al. Executive function and depression as indepen-dent risk factors for postoperative delirium. Anesthesiology 2009;110(4):781-7.

For 82 additional continuing nursing education arti-cles on geriatric topics, go to www.nursingcenter.com/ce.

13. van Munster BC, et al. The role of genetics in delirium in the elderly patient. Dement Geriatr Cogn Disord 2009;28(3): 187-95.

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18. Lemstra AW, et al. Pre-operative inflammatory markers and the risk of postoperative delirium in elderly patients. Int J Geriatr Psychiatry 2008;23(9):943-8.

19. Leung JM, et al. Does postoperative delirium limit the use of patient-controlled analgesia in older surgical patients? Anes-thesiology 2009;111(3):625-31.

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21. Morimoto Y, et al. Prediction of postoperative delirium after abdominal surgery in the elderly. J Anesth 2009;23(1):51-6.

22. Robinson S, et al. Aging and delirium: too much or too little pain medication? Pain Manag Nurs 2008;9(2):66-72.

23. Sieber FE, et al. Sedation depth during spinal anesthesia and the development of postoperative delirium in elderly patients undergoing hip fracture repair. Mayo Clin Proc 2010;85(1): 18-26.

24. Voyer P, et al. Prevalence and symptoms of delirium superim-posed on dementia. Clin Nurs Res 2006;15(1):46-66.

25. de Rooij SE, et al. Cytokines and acute phase response in delirium. J Psychosom Res 2007;62(5):521-5.

26. Inouye SK, et al. Clarifying confusion: the confusion assess-ment method. A new method for detection of delirium. Ann Intern Med 1990;113(12):941-8.

27. Ely EW, et al. Delirium in mechanically ventilated patients: va-lidity and reliability of the confusion assessment method for the intensive care unit (CAM-ICU). JAMA 2001;286(21):2703-10.

28. Rubin FH, et al. Sustainability and scalability of the hospital elder life program at a community hospital. J Am Geriatr Soc 2011;59(2):359-65.

29. Inouye SK, et al. The Hospital Elder Life Program: a model of care to prevent cognitive and functional decline in older hospitalized patients. Hospital Elder Life Program. J Am Geri-atr Soc 2000;48(12):1697-706.

30. Neitzel J, et al. Delirium in the orthopaedic patient. Orthop Nurs 2007;26(6):354-63.

31. Fong HK, et al. The role of postoperative analgesia in delirium and cognitive decline in elderly patients: a systematic review. Anesth Analg 2006;102(4):1255-66.

32. Farley A, McLafferty E. Delirium part one: clinical features, risk factors and assessment. Nurs Stand 2007;21(29):35-40.

33. Flagg B, et al. Nursing identification of delirium. Clin Nurse Spec 2010;24(5):260-6.

34. Gurlit S, Mollmann M. How to prevent perioperative delir-ium in the elderly? Z Gerontol Geriatr 2008;41(6):447-52.

35. Marcantonio ER, et al. Reducing delirium after hip fracture: a randomized trial. J Am Geriatr Soc 2001;49(5):516-22.

36. Lundstrom M, et al. Postoperative delirium in old patients with femoral neck fracture: a randomized intervention study. Aging Clin Exp Res 2007;19(3):178-86.

37. Palmisano-Mills C. Common problems in hospitalized older adults. J Gerontol Nurs 2007;33(1):48-54.

38. Lakatos BE, et al. Falls in the general hospital: association with delirium, advanced age, and specific surgical procedures. Psychosomatics 2009;50(3):218-26.

39. Hailey C. Taking steps to reduce fall injuries. Cape Cod Times 2010 Sep 23. http://www.capecodonline.com/apps/pbcs.dll/article?AID=/20100923/NEWS/9230327/-1/NEWS01.

mailto:[email protected]

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