Efeitos do Enjoo em Equipes Médicas de Transporte

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The Journal of Emergency Medicine, Vol 13, No 1, pp 15-20, 1995 
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THE INCIDENCE AND EFFECTS OF MOTION SICKNESS AMONG MEDICAL 
ATTENDANTS DURING TRANSPORT 
Mark S. Wright, LCDR MC USN, Carl L. Bose, MD, and Alan D. Stiles, MD 
Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina 
Reprint Address: Dr. Carl Bose, Division of Neonatal-Perinatal Medicine, CB#7596, 4th Floor, UNC Hospitals, University of North Carolina 
at Chapel Hill, Chapel Hill, NC 27599-7596 
0 Abstract -Motion sickness is a common and often de- 
bilitating problem. The purpose of this study was to deter- 
mine the incidence and effects of the motion sickness syn- 
dromes, the Nausea and Sopite Syndromes, among medical 
transport personnel. Members of the Transport Teams of 
the University of North Carolina Hospitals completed a 
questionnaire to identify a history of susceptibility to mo- 
tion sickness. An additional questionnaire evaluated each 
individual for symptoms of motion sickness during trans- 
port. The Digit Span Test portion of the Mini-Mental Sta- 
tus Examination (DST-MMSE) was used to evaluate cog- 
nitive function after transport. Control data on each 
subject were obtained by testing during nontransport 
shifts. The Nausea Syndrome was observed during trans- 
port in 46% of subjects; 65% experienced symptoms con- 
sistent with the Sopite Syndrome. Pretransport surveys 
were predictive of the Nausea Syndrome, but not of the 
Sopite Syndrome. The Nausea Syndrome was related to 
subjective assessments of the severity of motion experi- 
enced; the Sopite Syndrome did not correlate with the se- 
verity of motion. The DST-MMSE scores after transport 
were significantly lower than scores during nontransport 
periods in 85% of personnel. We conclude that transport 
personnel are susceptible to motion sickness manifested by 
both the Nausea Syndrome and the Sopite Syndrome. The 
presence of motion sickness is associated with a significant 
decline in performance on tests of attention and concentra- 
tion. 
Cl Keywords-motion sickness; transport; Nausea 
Syndrome; Sopite Syndrome 
INTRODUCTION 
Motion sickness is a common problem encountered 
during travel that may affect individuals riding in 
emergency medical vehicles. Research from the 
United States military services demonstrates that per- 
sonnel performing different functions within the 
same vehicle experience motion sickness at varying 
rates ( 1,2). These studies suggest that “riders” are 
more susceptible than vehicle operators. Therefore, 
attendants participating in medical transport may be 
particularly vulnerable to this problem. 
Motion sickness can be divided into two major 
symptom complexes: the Nausea Syndrome and the 
Sopite Syndrome (3-5). The symptoms of the Nau- 
sea Syndrome include stomach discomfort, nausea, 
increased salivation, sweating, pallor, and vomiting. 
The manifestations of the Sopite Syndrome are more 
subtle and include yawning and drowsiness in the early 
stages, followed by a disinclination for activity, either 
physical or mental, and for participation in group ac- 
tivities. In most cases, the Sopite Syndrome is the first 
manifestation of motion sickness, and it may be the 
sole manifestation, although it occurs much more fre- 
quently in association with the Nausea Syndrome. The 
severity of symptoms of the Sopite Syndrome may be 
so low that neither the subject nor people around the 
subject are aware of its manifestations (5,6). Even 
when adaptation results in the amelioration or resolu- 
RECEIVED: 18 October 1993; FINAL SUBMISSION RECEIVED: 15 March 1994; 
ACCEPTED: 22 April 1994 
15 
16 M. S. Wright et al. 
tion of the Nausea Syndrome, symptoms related to the 
Sopite Syndrome may persist. 
We assume that the quality of care provided by 
transport attendants suffering from the Nausea Syn- 
drome is impaired. However, it is possible that the 
Sopite Syndrome also has an impact on care. The 
purpose of this study was to determine the incidence 
of motion sickness syndromes among attendants dur- 
ing medical transport and to assess the impact of 
motion-induced illness on attention and concentra- 
tion. 
MATERIALS AND METHODS 
From November 1992 to May 1993 we studied all 26 
members of the University of North Carolina Hospi- 
tals (UNCH) Adult and Pediatric Transport Teams. 
The adult transport team includes registered nurses 
and paramedics; the pediatric transport team in- 
cludes pediatric-trained nurses and pediatric respira- 
tory therapists. All team members work 24-h duty 
shifts, which began at 7:00 AM. Air transports were 
performed via helicopter (BK 117 A3, Bokow Mes- 
serschmidt, Germany) and ground transports via 
hospital-owned ambulances. 
At entry into the study, all personnel completed a 
modification of the Motion Experience Question- 
naire as outlined by Miller and Graybiel(7), to iden- 
tify individuals susceptible to motion sickness. This 
historical-based analysis compares the type and num- 
ber of exposures to motion to the subject’s recall of 
the intensity of the symptoms experienced to estimate 
a level of susceptibility to motion sickness. Individu- 
als were classified as susceptible if their responses 
were comparable to responses of subjects in the 
Miller and Graybiel study who were found to be 
susceptible to illness when exposed to mild or moder- 
ate motion stimuli. Individuals were classified as not 
susceptible if their responses were comparable to 
Miller and Graybiel subjects who either did not de- 
velop motion-induced illness or developed illness 
only after extreme stimuli. In addition, personnel 
were questioned to determine if they had ever had an 
episode of motion-induced illness during transport. 
Each subject also completed a demographic profile 
to identify other medical problems. 
Evaluations to determine the presence of motion 
sickness and the effect of transport on attention and 
concentration were performed on each subject at the 
completion of an air or ground transport. For com- 
parison, control evaluations were performed during 
a shift in which a transport was not performed. All 
evaluations were performed during the first 12 h of 
the shift. The control evaluations were performed 
approximately the same number of hours from the 
beginning of a shift as the evaluations following 
transport. Prior to each evaluation, a pretest ques- 
tionnaire was administered to determine each sub- 
ject’s current health status, the number of hours of 
sleep in the preceding 24 h, and possible confounding 
factors affecting testing outcomes. Subjects were ex- 
cluded from testing if: (a) their last transport had 
occurred less than 48 h prior to testing, (b) they had 
been ill or nauseated in the previous 48 h, (c) they 
had taken any antimotion sickness medications or 
other medications that might induce nausea or 
drowsiness in the previous 24 h, (d) they had trav- 
elled in the copilot’s seat in the helicopter or in the 
front seat of the ground vehicle during the transport, 
(e) the transport used more than one mode of trans- 
portation (e.g., ground vehicle and fixed-wing air- 
craft), or ( f) the transport was completed beyond the 
first 12 h of the subject’s duty shift. Evaluations were 
performed immediately after patient care was trans- 
ferred to the receiving hospital personnel. If the 
transport was to another medical facility, testing was 
performed immediately upon return to UNCH. 
Each individual was evaluated for the presence of 
symptoms consistent with motion sickness (Table 1). 
The Nausea Syndrome was identified by either the 
presence of nausea or vomiting or two or more of the 
minor symptoms (7). The Sopite Syndrome was iden- 
tified by the presence of two or more of the six symp- 
toms commonly associated with this syndrome ( 5 ). 
To assessthe subject’s attention and concentra- 
tion, the Digit Span Test of the cognitive portion of 
the Mini-Mental Status Examination (DST-MMSE) 
was performed (8). The subject was given a series of 
numbers to repeat forward; each series increased by 
one additional digit until the subject was unable to 
accurately repeat the series. Each subject was then 
Table 1. Symptoms of the Motion Slckneu Syndromes: 
The Nausea and Soplte Syndromes 
Nausea Syndromea 
Major symptoms 
Nausea 
Vomiting 
Minor symptoms 
Warmth/flushing 
Dizziness 
Diaphoresis 
Pallor 
Salivation 
Stomach awareness 
Stomach discomfort 
Sopite Syndrome b 
Drowsiness 
Malaise 
Yawning 
Headache 
Disinclination for work 
Lack of participation in group activities 
‘From Miller and Graybiel(7). 
bFrom Graybiel and Knepton (5). 
Motion Sickness During Transport 17 
given a series of numbers to repeat backwards in a 
similarly progressive manner. The subject was given 
credit for the total number of series correctly com- 
pleted. Attention and concentration following trans- 
port were considered to be adversely affected if the 
subject was (a) unable to repeat one less forward 
series and one less backward series, (b) unable to 
repeat two less forward series or two less backward 
series, or (c) performed worse than either “a” or “b” 
when compared to the nontransport evaluation. 
Control evaluations were performed in the same 
manner as posttransport evaluations. All control 
evaluations were performed at least 8 h after the start 
of the subject’s duty shift. Prior to testing, subjects 
were prescreened to rule out recent motion experi- 
ences. At the completion of this control evaluation, 
each subject was screened for normal vestibular re- 
sponses using the Romberg and the Walk On Floor 
Eyes Closed tests (9). 
All subjects were evaluated after at least one trans- 
port, either ground or helicopter, and on a nontrans- 
port shift. All testing was performed by the same 
examiner. This study was approved by the Commit- 
tee on the Protection of Rights of Human Subjects 
at the University of North Carolina at Chapel Hill. 
Informed consent was obtained from all participants. 
Two-tailed, paired t-tests were used to compare the 
results of the DST-MMSE. 
RESULTS 
On the Motion Experience Questionnaire, 62% of 
subjects received scores indicative of a susceptibility 
to motion-induced illness. All subjects, including 
those determined not to be susceptible, reported at 
least one episode of motion sickness during their ex- 
perience as a medical attendant on transport. Vestib- 
ular perception tests were completed by all study sub- 
jects during nontransport shifts. No abnormalities of 
vestibular function were identified. 
A total of 30 posttransport tests were performed 
on the 26 study subjects. Evaluations were performed 
after 19 air transports and 11 ground transports. 
Four individuals were examined after both air and 
ground transports. Only the first evaluation for these 
individuals was used in the analysis of the effect of 
motion sickness on test performance (Figure 1). All 
evaluations were used in the comparison of the rela- 
tive effect of air and ground transport. Transport 
evaluations were performed earlier in the work shift 
compared to control evaluations (8.4 f 1.5 h versus 
9.2 f 0.5 h; P = O.OOS), with a range of 5 to 11.5 h 
- NONTRANSPORT TRANSPORT 
NAUSEA SOPITE NO M S 
Figure 1. Scores on the Digit Span Test of the Mini-Mental 
Status Examlnatlon during nontransport shlfta compared to 
scores immediately following transport for Indivkfuals expe- 
rlencing the Nausea Syndrome (n = 12), the Sopite Syn- 
drome (n = 17), and no motion sickness (n = 0). Scores 
durlng nontransport shifts are repreaented by solid bars ( f 
standard deviation); scores immedfatefy after tranaport are 
represented by hatched bars. There was a signlfkant da 
cline in scores for Individuals experfencing both the Nausea 
and Sopite Syndrome that was not observed in individuals 
who did not experience motion sickness. 
for transport shifts and 8 to 10 h for nontransport 
shifts. 
The Nausea Syndrome was identified in 12 (46% ) 
of the 26 subjects (Table 2). No individual was nau- 
seous at the time of examination. All but one individ- 
ual experiencing the Nausea Syndrome had a history 
consistent with susceptibility to motion-induced ill- 
ness from the screening questionnaire; however, not 
all subjects with positive histories experienced the 
Nausea Syndrome. Presence of the Nausea Syn- 
drome was directly related to the subjective assess- 
ment of the severity of motion experienced, 
Seventeen individuals (65 % ) experienced the So- 
pite Syndrome; nine of these subjects also experi- 
enced the Nausea Syndrome. No correlation was 
found between the motion sickness susceptibility de- 
termined from the motion sickness screening ques- 
Table 2. Incidence of the Nausea and Sopfte Syndromes in 
Relation to a History of Susceptibility 
Nausea 
Syndrome 
Yes No 
Sopite 
Syndrome 
Yes No 
Yes 11 5 7 3 
Susceptibility to 
motion sickness’ 
No 1 9 10 6 
“Susceptibility determined by a modification of the Motion Ex- 
perience Questionnaire (7). 
18 M. S. Wright et al. 
tionnaire and the occurrence of the Sopite Syndrome. 
Six individuals (23%) experienced neither the Nau- 
sea nor the Sopite Syndrome. 
All transports were between hospitals; there were 
no prehospital transports. The duration of time be- 
tween departure from the referring hospital to arrival 
at UNC Hospitals ranged from 15 to 34 (mean 36) 
min for air transports, and from 25 to 90 (mean 64) 
min for ground transports. There was no correlation 
between the duration of this time and the presence of 
either of the motion sickness syndromes. 
Fifteen females and 11 males were enrolled in the 
study. There was no significant difference in the inci- 
dence of motion sickness between females and males 
in the current study (P = 0.624). The years of ser- 
vice on the transport team ranged from less than 1 
year to 6.5 years. There was no relationship between 
the length of service and the likelihood of developing 
motion sickness. The median hours of sleep during 
the 24 h prior to transport shifts was 7 h (range 5 to 
11). There was no relationship between the duration 
of sleep and either of the motion sickness syndromes. 
The Nausea Syndrome was more common during air 
transport than during ground transport ( 11 of 19 ver- 
sus 1 of 11, respectively). However, the incidence of 
the Sopite Syndrome during air and ground transport 
was similar ( 10 of 19 versus 7 of 11). 
The DST-MMSE was performed at a mean of 21 
min (range 8 to 31 min) after the completion of 
transport. Performance was worse after transport 
compared to the nontransport evaluation in 20 of the 
26 subjects. There was a decrement between non- 
transport and transport scores of subjects experienc- 
ing both the Nausea Syndrome (13.8 i 0.8 versus 
11.1 f 1.2, respectively; P < 0.0001) and the So- 
pite Syndrome (13.9 rt 1.0 versus 10.9 f 1.2, re- 
spectively; P < 0.0001) (Figure 1). However, the 
decrement in score was similar for those experiencing 
the Nausea Syndrome compared to the Sopite Syn- 
drome. There was no difference between nontrans- 
port and transport scores of the six individuals who 
did not experience motion sickness ( 12.5 versus 11.7, 
respectively). The decrement did not correlate with 
the subjective evaluation of the severity of motion 
experienced by individual subjects. The DST-MMSE 
scores were significantly lower after transport com- 
pared to nontransport evaluations for both air ( 13.6 
f 1.0 versus 11.2 f 1.1, respectively; P < 0.0001) 
and ground (13.7 f 1.4 versus 11.3 f 1.3, respec- 
tively; P < 0.0001) transports (Figure 2). However, 
the decrement in score was similar for both air and 
ground transport. There was no relationship between 
duration of transport and decrement in score. The 
median hours of sleep during the 24 h prior to shifts 
duringwhich control evaluations were performed 
- NONTRANSPORT TRANSPOAT 
GROUND AIR 
Figure 2. Scores on the Digit Span Test of the Mini-Mental 
Status Examlnatlon during nontmnsport shifts compared to 
scores immediately following transport In ground ambu- 
lances and hellcoptem. Scores during nontransport shifts 
am represented by solid barn (i standard deviation); 
scores immediately after tmnsport are represented by 
hatched bars. There was a slgnlfloant decline In scores, re- 
gardless of the mode of tmnsportatlon. However, there was 
no dlfferencs In the magnltude of decline between modes of 
transportation. 
was 7 h (range 6 to 11.5). There was no relationship 
between DST-MMSE scores and duration of sleep. 
DISCUSSION 
The term “motion sickness” was introduced by Irwin 
in 1881 (12) and came into wide use during World 
War II when the effects of sea and air transport on 
military personnel were reported. It is generally ac- 
cepted that, given severe enough stimuli over a pro- 
longed period, almost any subject will experience 
nausea. The degree of susceptibility to motion sick- 
ness has also been shown to be an individual charac- 
teristic (13-15). In a study of student pilots, 37Vo of 
individuals who experienced nausea during their first 
flight had a recurrence of nausea on subsequent ex- 
posures to motion. However, if there was no motion 
sickness during their first exposure, only 2% devel- 
oped symptoms of nausea ( 13). 
Because “riders” are reported to be more suscepti- 
ble to motion-induced illness than vehicle operators 
(1,2), medical attendants on transport, as demon- 
strated by this study, are highly susceptible to motion 
sickness. Although this study investigated the prob- 
lem of motion sickness during interhospital transport 
only, the findings may also be applicable to prehospi- 
tal transport. There was no relationship between the 
duration of transport and the incidence or severity of 
effects. The Nausea Syndrome was extremely uncom- 
mon during ground transport. Therefore, the Nausea 
Syndrome may not be a significant problem among 
Motion Sickness During Transport 19 
prehospital ambulance attendants. However, the 
likelihood of developing the Sopite Syndrome ap- 
pears to be independent of the mode of transporta- 
tion and, therefore, may be common during prehos- 
pita1 transport. 
In addition to causing the symptoms of motion 
sickness, the transport environment affected atten- 
tion and concentration. Performance on the DST- 
MMSE was impaired by transport in all but six sub- 
jects when compared to nontransport working 
conditions. Attribution of the decrement in DST- 
MMSE scores to motion sickness cannot be made 
with certainty. However, our finding of no decre- 
ment in the six individuals without motion-induced 
illness supports the hypothesis that motion sickness 
was responsible for the decline in attention and con- 
centration. Subject fatigue may also have resulted 
in impaired performance. However, this possibility 
seems unlikely because testing occurred earlier in the 
transport shift than on nontransport shifts and does 
not account for the unaffected performance of sub- 
jects with no motion sickness. 
Symptoms associated with the Nausea Syndrome 
are known to disappear within minutes after the ces- 
sation of exposure (4). Therefore, the DST-MMSE 
was administered as soon after transport as patient 
care allowed so that recovery from the effects of mo- 
tion sickness were minimized. Although the length of 
time between transport and testing may have affected 
performance, delays should have resulted in underes- 
timating the effects of transport. We could find no 
information in the literature regarding the duration 
of the Sopite Syndrome once exposure has ended. 
The importance of a decline in performance on 
the DST-MMSE among medical attendants is not 
known. However, the DST-MMSE is a measure of 
cognitive function ( 16) and most often is found to be 
abnormal when there is anxiety-induced interference 
or “impairment associated with a cerebral disorder” 
(17). Therefore, we speculate that conditions that 
impair performance on the DST-MMSE may affect 
reasoning and problem solving, functions vital to pa- 
tient care. Despite the rapid disappearance of symp- 
toms associated with motion sickness, a decline in 
performance on the DST-MMSE was detectable up 
to 31 min after cessation of exposure to motion. It 
is likely that the demonstrable effect of motion on 
attention and concentration would have been greater 
had testing been performed during transport. 
In our study, the Sopite Syndrome was a more 
common manifestation of motion sickness than the 
Nausea Syndrome, and its occurrence could not be 
predicted based on a previous history of motion sick- 
ness. Disinclination for mental work and the lack of 
participation in group activities are symptoms of the 
Sopite Syndrome. These symptoms may be com- 
pounded by the deficits in attention and concentra- 
tion that we have observed in association with both 
syndromes. Therefore, even the more subtle manifes- 
tations of motion sickness associated with the Sopite 
Syndrome are likely to impair the performance of 
medical attendants during transport and adversely 
affect the interaction of transport personnel with 
other personnel. 
Several investigators have reported success in con- 
ditioning motion sickness susceptible individuals to 
the effects of motion-induced nausea. These methods 
include biofeedback ( 18,19), relaxation techniques 
combined with exposure to spatial disorientation ma- 
neuvers (20), angular accelerations in a slow-rotation 
room (21), and repeated Coriolis stimulation over 
a period of 7 d (22). This suggests that prolonged 
exposure to the transport environment may lessen 
the susceptibility of medical attendants to the Nausea 
Syndrome. In contrast, there are no reports that con- 
ditioning lessens susceptibility to the Sopite Syn- 
drome, although anecdotal reports suggest that pro- 
longed exposure to motion may lead to attenuation 
of symptoms (5). Because motion-induced illness, 
particularly the Sopite Syndrome, is extremely com- 
mon among transport personnel and, because it is 
likely to affect performance, further research should 
investigate the effects of motion sickness on patient 
care. In addition, specific therapies to alleviate the 
Sopite Syndrome should be investigated. 
Acknowledgment-The authors would like to thank the 
members of the Carolina Air Care Transport Teams for 
their cooperation and patience during this study. 
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