The effects of sedatıon wıth ıntravenous mıdazolam ın 100 patıents undergoıng upper gastroıntestınal endoscopy

UPPER GASTROINTESTINAL ENDOSCOPY

O bjective: The use of sedation in upper

gastrointestinal

endoscopy

is

widespread

because of better patient tolerance. As this

sedation

is

usually

performed

by

non­

anesthesiologists in and outside of hospital

settings, possible adverse effects arising during

the procedure must be dealt with carefully. In this

study, the safety and efficacy of midazolam for

conscious sedation in 100 patients undergoing

upper gastrointestinal endoscopy were evaluated

prospectively.

Patients and Methods: Hundred consecutive

patients undergoing upper gastrointestinal

endoscopy were sedated with intravenous

midazolam. The dose of midazolam was titrated

according to the patient’s need and the duration

of the procedure. Heart rate and oxygen

saturation of all the patients were continuously

monitored during the procedure and any

complications were recorded. The amnesic effect

of midazolam and patient comfort were also

evaluated.

Results: During the procedure, absence of

oxygen desaturation (Sa02 > 95%) was found in

80%, mild oxygen desaturation (95% > Sa02 >

92%, at least 15 seconds duration) in 16%, and

severe oxygen desaturation (Sa02 < 92%, at

least 15 seconds duration) in 4%. Twenty-six

patients had tachycardia only during the insertion

of the endoscope, 17 patients had it throughout

the procedure. Ventricular premature beats were

recorded in two patients. Different degrees of

amnesia were seen in 60% of the patients and

the comfort level was excellent in 41%, good in

43%, and fair in 16%.

Conclusion: Sedation of patients undergoing

upper

gastrointestinal

endoscopy

with

intravenous midazolam results in better tolerance

of the procedure. Routine monitoring must be

provided because of the risks of desaturation and

arrhythmia.

K e y W o r d s :

Midazolam, Conscious sedation,

Upper gastrointestinal endoscopy.

IN T R O D U C T IO N

Despite the fact that the vast majority of

diagnostic endoscopic procedures can be

performed under topical throat anesthesia alone,

it has been shown that the use of sedation results

in better patient tolerance and less hemodynamic

stress in response to insertion and manipulation

of the endoscope (1). Midazolam is the most

Sedation with intravenous midazolam in upper gastrointestinal endoscopy

widely used agent for this purpose, due to its

short acting time and amnesic property (1). The

aim of this study was to evaluate the effects of

sedation in 100 patients undergoing upper

gastrointestinal endoscopy at the Marmara

University Institute of Gastroenterology between

November 2000 and March 2001.

M A T E R IA L S A N D M E T H O D S

After giving information about the procedure, the

age, gender, body weight, and prior experiences

(a history of previous upper gastrointestinal

endoscopy)

of

100

consecutive

patients

undergoing upper gastrointestinal endoscopy

were recorded. Associated medical illnesses

were graded according to the American Society

of

Anesthesiologists’

Physical

Status

Classification (ASA grade) (ASA I: A healthy

patient without any systemic medical problems

other than surgical; ASA II: A patient with mild

systemic disease that results in no functional

limitation; ASA III; A patient with severe systemic

disease that results in functional impairment;

ASA IV: A patient with a severe systemic disease

that is a constant threat to life; ASA V: A

moribund condition in a patient who is not

expected to survive with or without operation;

ASA VI: Declared brain death whose organs are

being

harvested

for

transplantation;

E:

Emergency operation is required) (2). Oxygen

saturation and heart rate were continuously

monitored from 10 min. before sedation until the

end of the endoscopy. Topical pharyngeal

anesthesia was administered with lidocaine 10%

(Xylocain®, Eczaciba§i). A 22-gauge cannula

was placed intravenously for application of the

sedation drugs. Level of sedation was assessed

using the following sedation scale: 1: Awake,

alert, agitated; 2: Slightly drowsy, easily aroused;

3: Frequently drowsy, arousable, drifts off to

sleep during conversation; 4: Somnolent,

minimal or no response to physical stimulation. A

bolus

dose

of

0.04

mg/kg

midazolam

(Dormicum®, Roche) was given intravenously 2

min. before the esophageal intubation by the

same anesthesiologist. For patients aged over 60

years 1 mg. midazolam was used. Sedation level

was assessed between 2 and 3 by giving 50% of

the initial dose as required. The procedures were

performed by three different endoscopists. The

duration of the procedure and complications such

as a fall in oxygen saturation and arrhythmia

were recorded. Oxygen desaturation was

assessed as absence of oxygen desaturation

(Sa02 > 95%), mild oxygen desaturation (95% >

Sa02 > 92%, at least 15 seconds duration), and

severe oxygen desaturation (Sa02 < 92%, at

least 15 seconds duration). Before discharge,

procedural amnesia was reported by the patient

according to a four-point scale (1: Do not

remember the procedure, 2: Remember only the

esophageal intubation, 3: Remember only the

withdrawal of endoscope, 4: No amnesia) and

the patient’s comfort level was assessed

according to a “comfort score” (1: Excellent, 2:

Good, 3: Fair, 4: Poor).

All values were expressed as mean ± standard

deviation. Spearman’s rank test was used to

analyze the correlations of oxygen desaturation

with age, body weight or duration of procedure

and chi-square test for gender. A P value less

than 0.05 was considered statistically significant.

RESU LTS

A total of 100 patients received midazolam (58

women and 42 men). The demographic

characterization and a prior experience of the

patient, duration of the procedure, and the dose

of midazolam used are shown in Table I. The

baseline Sa02 was 98.3 ± 1.0 %. During the

procedure, there was no desaturation in 80%,

mild oxygen desaturation in 16%, and severe

oxygen

desaturation

in

4%

(Fig

1).

Supplementary oxygen at 5 L/min via nasal

cannula was given to patients in the severe

oxygen desaturation group. Age (correlation

coefficients.19, p =0.058), gender (p=0.06),

body weight (correlation co e fficie n ts. 19, p

=0.054), or total endoscopy time (correlation

coefficients.16, p =0.11) was not related to the

degree of oxygen desaturation. In ASA III

patients, severe desaturation was found in 14.3%

while it was 3.2% in ASA l-ll patients (Fig 2).

Twenty-six patients had tachycardia only during

the insertion of the endoscope, 17 patients had it

throughout the procedure. Ventricular premature

beats were recorded in two patients but there

was no need to use an anti-arrhythmic agent (Fig

3). There were no deaths, episodes of cardio­

respiratory arrest, or pulmonary aspirations

amoung our patients.

T a b l e I.: D e m o g ra p h ic c h a r a c te r iz a tio n a n d p rio r e x p e r ie n c e of p a tie n t, d u ra tio n of p r o c e d u r e a n d d o s e of m id a z o la m u s a g e . Female Male (n=58) (n=42) Age (year) (mean±SD) 49 ± 14 45 ± 15 Body weight (kg) (mean ± SD) 64 ± 12 76 ±12 ASA grade (number of patients) I 33 27 II 23 10 III 2 5 Prior experience (number of patients) 18 16 Duration of procedure (minute) (mean ± SD) 9.4 ±4.2 11.3 ±6.3 Midazolam dose (mg) (mean ± SD) 3.8 ±1.2 3.9 ±1.1

ASA grade: American Society of Anesthesiologists Physical Status Classification.

O xygen desaturation

| Mild desaturation | Severe desaturation

G ender

F l g . l : O xygen d e s a tu ra tio n of p atien ts.

A S A I & II A S A III

ASA Classification

ASA: American Society of Anesthesiologists Physical Status Classification

F ig . 2 : O xygen d e sa tu ra tio n of p a tie n ts a c co rd in g to th e ASA Classification. s_c <0 a ■B È E Arrhythmia Normal sinus rhythm Tachycardia during intubation Tachycardia during procedure I B Ventricular prem ature beats

G ender

F i g .3 : Arrhythm ia in patients.

T h irty p e rce n t of p a tie n ts did not re m e m b e r the p ro c e d u re , 2 6 % re m e m b e re d o n ly th e e s o p h a g e a l in tu b a tio n , 4 % re m e m b e re d on ly the w ith d ra w a l ot th e e n d o sco p e , and 4 0 % did not h a v e a n y a m n e s ia . T h e c o m fo rt le v e l w a s e x c e lle n t in 41% , g ood in 43% , and fa ir in 16% .

DISCUSSION

C o n scio u s se d a tio n is the use of m e d ic a tio n to m in im a lly d e p re s s the level of c o n s c io u s n e s s in a p a tie n t w h ile a llo w in g th e p a tie n t to c o n tin u a lly and in d e p e n d e n tly m a in ta in a p a te n t a irw a y and re s p o n d a p p ro p ria te ly to v e rb a l c o m m a n d s a n d /o r ge n tle s tim u la tio n (3). T he ta s k fo rc e of th e A m e ric a n S o c ie ty o f A n e s th e s io lo g is ts d e c id e d th a t the te rm “s e d a tio n and a n a lg e s ia ” m ore a c c u ra te ly d e fin e s th is th e ra p e u tic goal than d o e s the c o m m o n ly used te rm “c o n s c io u s s e d a tio n ” (4). T his type of s e d a tio n can be used in p ro c e d u re s such as all typ e s of e n d o sco p y, lu m b a r p u n c tu re , c a rd io v e rs io n , w o u n d care, burn d e b rid e m e n t, b one m a rro w a s p ira tio n and p la c e m e n t o r re m oval of im p la n te d d e v ic e s and tubes. It can also be used in p ro c e d u re s during w h ich the p a tie n t s u ffe rs a n x ie ty but m u st rem ain as m o tio n le ss as p o ssib le , such as m a g n e tic re s o n a n ce im aging a nd c o m p u te d to m o g ra p h y scan. A n o th e r type of se d a tio n , d e e p s e d a tio n or M o n ito re d A n e s th e s ia C a re (M A C ), u s e s m e d ic a tio n to in d u c e a c o n tro lle d s ta te of d e p re s s e d c o n s c io u s n e s s o r u n c o n s c io u s n e s s in w h ic h the p a tie n t m ay e x p e rie n c e p a rtia l or co m p le te loss of p ro te c tiv e re fle x e s in c lu d in g the

Sedation with intravenous midazolam in upper gastrointestinal endoscopy

a b ility to in d e p e n d e n tly a nd c o n tin u o u s ly m aintain a p a te n t a irw a y (3). H ow ever, only a n e s th e s io lo g is ts m u st a d m in is te r this type of se dation . O n the o th e r hand, the p a tie n t m ay p ro g re ss fro m o ne d e g re e of se d a tio n to anothe r d e p e n d in g on his u n d e rly in g m edical status, the m e d ica tio n s a d m in is te re d , d o s a g e and route of a d m in is tra tio n . E xce ssive se d a tio n m ay result in ca rd ia c or re s p ira to ry d e p re s s io n that m ust be ra p id ly re c o g n iz e d and a p p ro p ria te ly m anaged to avoid the risk of h yp o x ic brain dam age, cardiac arrest, o r d e ath. So, o b s e rv a tio n and m onitoring of the p a tie n t by a person skille d in adva n ce d life s u p p o rt is very im p o rta n t in th is type of p rocedure (5). In this study, an a n e s th e s io lo g is t m aintained th e s a m e level of s e d a tio n . T his is the m ain reason fo r the low c o m p lic a tio n rate. H ow ever, s e d a tio n d u rin g u p p e r g a s tro in te s tin a l e n d o s c o p y is u s u a lly p e rfo rm e d by n o n ­ a n e s th e s io lo g is ts in and o u ts id e of h o s p ita l settings. B e cause of sa fe ty reasons, th e re are s tu d ie s offe rin g only to p ic a l th ro a t an e sth e sia . Tan and F re e m a n (6) stu d ie d 2 44 c a se s and

fo u n d th a t o n ly 32 % of p a tie n ts w h o had th roat spray to le ra te d the e n d o s c o p y w e ll, co m p a re d to 70% o f th o se w h o c h o s e s e d a tio n . T h e y claim ed th a t m ale p a tie n ts, th o s e w ith low er a n xiety levels, and th o se o v e r 50 y e a rs old, to lerated e n d o s c o p y w ith th ro a t sp ra y better. C a m p o et al (7) stu d ie d 509 p a tie n ts u n d e rg o in g d ia g n o s tic g a s tro s c o p y a fte r the a d m in is tra tio n of topical ph a ryn g e a l a n e s th e s ia , w ith o u t s e d a tio n . P atient to le ra n ce w a s p o o r in 84 of 2 73 (31% ) patients un d e rg o in g g a s tro s c o p y fo r the first tim e, and in 61 of 236 (26% ) p a tie n ts w ith p rio r exp e rie n ce . In o u r study, th e re w a s no p o o r p a tie n t to le ra n ce even in the “ no a m n e s ia ” group.

H y p o x ia is o n e o f th e m o s t im p o rta n t c o m p lic a tio n s of u p p e r g a s tro in te s tin a l e n d o s c o p y (1). In th is study, w e found absence of oxyg e n d e s a tu ra tio n in 80% , m ild oxygen d e s a tu ra tio n in 16% , a n d s e v e re o x y g e n d e s a tu ra tio n in 4% . W ang et al (8) studied

o xyg e n sa tu ra tio n using p u lse o x im e try in 1 0 0

se d a te d and 1 0 0 n o n -s e d a te d p a tie n ts b reathing

room a ir d u ring d ia g n o s tic u p p e r g a stro in te stin a l e n d o sco p y. H yp o xia ( S a 02 < 92% , at le a st 15

se co n d s d u ra tio n ) o cc u rre d in 17% and 6% of

s e d a te d p a tie n ts an d n o n -s e d a te d p a tie n ts , re sp e c tiv e ly (p < 0 .0 3 ). M ild d e s a tu ra tio n ( S a 02 <

94% , less than 15 se c o n d s d u ra tio n ) o ccu rre d in 4 7 % of se d a te d p a tie n ts c o m p a re d w ith 12% of

n o n -s e d a te d p a tie n ts (p < 0 .0 0 1 ). S e d a tio n s ig n ific a n tly in c re a s e s th e in c id e n c e of d e sa turatio n and hypoxia but they can occur w ith o u t sedation also. Iwao et al (9) studied 120 p a tie n ts u n d e rg o in g n o n -s e d a te d d ia g n o s tic u p per gastro in te stin a l e n dosco py and observed no oxygen d e sa turatio n (S a02 > 95% ) 56% , mild oxygen d e sa tu ra tio n (95% > S a 02 > 90% ) 35% ,

and severe oxygen d e sa turatio n ( S a 02 < 90% )

9% . T hey claim ed that age, gender, sm oking, hem oglobin level, body m ass index, or total end o sco p y tim e w ere not related to the degree of o x y g e n d e s a tu ra tio n a nd re c o m m e n d e d c o n tin u o u s m onitoring of arterial oxygena tion in all patients during the procedure. Basal S a 02 <

95% , re sp ira to ry disease, m ore than one attem pt needed fo r intubation, em erg e n cy procedure and A S A score of III or IV are found as predictive fa c to rs of o xy g e n d e s a tu ra tio n during upper g a s tro in te s tin a l e n d o s c o p y in n o n -s e d a te d p a tients (10,11). Such patients require very close m o n ito rin g and e n d o s c o p is ts s h o u ld be e sp e cia lly alert to the p o ssib ility of respiratory d e p re s s io n in th e s e c a s e s . T h e e ffe c t of s u p p le m e n ta ry nasal oxygen is also studied in s e d a te d p a tie n ts and it is fo u n d th a t su p p le m e n ta ry oxygen a b o lish e s desaturation and hypoxia (8). T he routine use of supplem ental

oxygen w ould g reatly reduce this unnece ssary risk to patients.

U p p e r g a s tro in te s tin a l e n d o s c o p y is o ften acco m p a n ie d by ta ch yca rd ia because of the stress response (12). T his can be dang e ro u s for p a tients with co ro n a ry h eart dise a se (C H D ). E le c tro c a rd io g ra p h re co rd in g usin g a H o lte r m onitor w as perform ed in 71 patients w ith stable C H D , to c h e ck fo r s ile n t ischem ia, and during g a s tro s c o p y , 30 p a tie n ts (4 2 % ) had s ile n t is c h e m ia , b u t o n ly 1 p a tie n t (1% ) b e c a m e

sym p to m a tic (13). W ilco x et al (14) studied 25 h o s p ita liz e d p a tie n ts w ith w e ll-d e fin e d C H D d u rin g e n d o s c o p ic p ro c e d u re s re q u irin g in travenou s sedation . T w e n ty fo u r percent of p a tie n ts had o ne o r m o re e p is o d e s of e le c tro c a rd io g ra p h ic is c h e m ia d u rin g the recording p eriods. S e dation m ay provide som e p ro te c tio n a g a in s t h e m o d y n a m ic s tre s s in re sponse to insertion and m anipulatio n of the e n d o sco p e (15). But ta c h y c a rd ia w as seen in 43 % of the p a tients in o u r study, although they had an a c ce p ta b le level of sedation.

In c o n clu sio n , s e d a tio n a p p lie d by a skilled person during u p p e r g a s tro in te s tin a l end o sco p y provides b e tte r p a tie n t to le ra n c e w ith a low er c o m p lic a tio n ra te . A s th e re a re ris k s of d e s a tu ra tio n a nd a rrh y th m ia d u rin g th is procedure , even w ith o u t se dation , ad ve rse risk fa cto rs should be c a re fu lly identified and routine m onitoring, at le a st w ith a pulse o xim eter, should be carried out.

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