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Pain and paresthesia in patients with healed burns: An exploratory study
Key Words Chronic
pain,
paresthesia,
bunt
Most of the literature on burns is devoted to the problems encountered during the hospitalization phase. Very little empirical datil exist on the long-term effects of burn il!juries. ‘I’he presence of chronic PilinfUl or paresrlwt ir:* sensations’ in the healed wounds sl~ould not be surprising in view of Ihe fact Ihat the injury often Address reprint requests to: Manon
ChoiniPre, Phi), Burn Centre, Hotel-Dieu Hospital of Montreal, 3810 St-Urbain, Montreal, Quebec, Canada, H2W 1’1’8. Acceptedfor publication: April 8. I99 I. wl’he term “paresthetic” is used to refer to a nonpainful abnormal sensation. This definition is consistent with the recommendations of the Subcommittee on Taxonomy of the International Association for the 0 U.S. Cancer Pain Relief Committee. 1991 Published by Elsevier, New York. New York
involves dcslruction of nerve receptors iIlld fihers. Neuralgia is conn~u~nly repork~l in other types of injury involving damage to periphera! nerves.“.” Furthermore, these patients undergo repeated, complex surgical treatments, such as skin grafting, and many develop hypertrophic scars or contracn.ue~, any of which may be potential
causes
of’ pcrsislent
pain
and
paresthe-
sias.“-7
Lane and Hogen, ’ McBride,” and Ton”’ have anecdotal reports of chronic pain or paresthesia in healed burns, but the problem is provided
Study of Pam. It is recommended that the term “}~itresthesi;l” be used I0 dcscribe an abnormal scnsaLion which is not unpleasant while lhc term “tlyscsthcsia” should be employed prcfcrcntially fin an abnormal
sensarion which is unpleasant.
Choinikre et al.
-138
poorly documented in the literature. On the basis of their clinical experience, Marvin and Heimbach”*” maintain that only a minority of burn patients complain of pain after COtnpkte scar maturation. However, cases may go undiagnosed because they coincide with postinjury depression syndrome,” and a large number of patients are lost to follow-up because of the long-term nature of the recovery process.13 Therefore, it is possible that the prevalence of chronic sensory problems has been underestiwtatetl in burn patients. A recent study tends to support this hypothesis. During ~XiU1\itNith Of ~utaix~i~s sensitivity after grafting, Ward id colleagues’” noticed il Whtllid proportion of patients who complained of neuralgic problems: 25% of the examined patients (N = 60) rcported p”irr in the grafted iINXl!J, 25% had an inchronic prurirus, and 50% rcprtcd CltiWXi sensitivity to temperature, Further studies are clearly needed to document the long-term effects of burn injuries. The lack of quantitative information about this issue often produces difficulties for both patients and physicians, both of whom sesk to have these incapacities acknowledged by com“3” For example, although I4 described patients who experienced difficulty in returning to outdoor work because of intolerance to extremes of tetuperature, no mention is made of the specific sensory difficulties encountered by burn victims in the guidelines for evaluation of pwmanem ‘rment that are published by compensation ii?s (e.g., The American Medical Associaand the C~ommissisn de ia SantC et de la S&uritC au Travait”). The present study was dcsi fled 10 dwument he
pmvaknee
and
cha
sties of pain and p of patients with t may contribute to the development of these problems were also mplnrecl by examininfi: the intfuencc of vari&des such RS the patients’ demographic attributes, the characteristics of the burn injuries, the t~quired treatment, and the length df time since injury.
paresthesia problems in heakd burns. Factors
Journal of Pain and Symptom Management
Dieu Hospital of Montreal (N = 73) or at the Montreal General Hospital (N = 3 1) between April 198 1 and March 1987. The subjects were recruited from a list of consecutive admissions during this period by using a procedure that ensured that the names of the patients were not released to the investigators unless the patient
expressly granted permission. The medical record offices prepared a list of patients that excluded those who were deceased or who were classified as psychiatric patients. Then a letter was smt to each candidate by a staff member of the hospital who was assigned to patient recruitment for the present study. The letter ex-
plained the study requirements, and was nccompanied by a response card and a stamped rnvolope to be returned to the person in charge of patient recruhment. This persat~ compiled a list of volunteer participants (names. addresses, and phone numbers) and gave it to a specially trained research assistant, who then contacted each patient. Of the 379 candidates identified by the medical records offices, 295 were located and contacted by mail. One hundred and thirty-four (46%) consented tu p:lrticipate in the study, 15 (5%) refused, and 145 (49%) did not atwm.
Thirty patients were escluded during the course of the study for various reasons (inability to ~~~~~~~~~ll~~~~~te hecause of language or ability, presence of a disorder affecting functions such as diabetic neuropathy. cessive unavailability for the interview), ;I subsample of 104 participants (35%).
we Data were collected using structured telephone interviews. Many patients lived outside of the Montreal area, and telephone interviews, as opposed to written questionnaires, were considered to be the most appropriate and reliable method to carry out data collection in the context of the present exploratory study. All tele-
phone interviews were performed by two experienced, master’s level research assistants. Each
assistant was extensively trained by one of the investigators (MC.). This training ensured a standardized and uniform utikation of the structured
subjects were 10-l adult patients who had pitakd for burn injuries at the Hotel-
mental sensory or sucleaving
interview
protocol,
and frequent
meetings were organized to review and discuss the completed questionnaires. During the interview, the patients were asked
eir healed woun1ds. protocol was Conap’BS
At the end of the study, all the patients’ medical charts were reviewed I.0 collect infi~rmation about the characteristics of the burns (etij.llogy, size, location). Burn size (secoI1d- ;uid third-drgree burns) was calculated by using the Rule of Nines,” and was expressed as the perceljtitge of total body surface area burned. ‘l’he type cl{‘ treatment carried oul (e.g., skin grafi) and the length of time elapsed since IPW injury werr also recorded.
When
the
104 interviewed
cotnpao~ed with
the
275
lrarticip;rnts nanintervicwed
wc~rc pa-
found with respect. to age (II - 0.65, P > .05)* sex (x2 ” .03, P > .05) and extent of the burn injuries (I = 0.34, P > .OS). The demographic and medical characteristics of the subsample of participants (N = 104) are summarized in Table 1. tients,
no
significant
Pain Smalim
dilf+rcnce
in
was
Ifeahd Bumzs
Prevalence Thirty-six of the 104 participants, i.e., 35% of the sample, reported pain in the healed burns. All patients were interviewed at least 1 yr or more after their injury (mean
ChoinDre et al.
/
Journal of Pain and SymptomMnnagtvnent
/’
_’
100
60
a&
(0 - not at all, 4 = extremely)
in
is displayed
common in burn patients even many years after the accident.
Bum
~~~~p~~t~~t~~~ When patients had paresthesias
F~&FM Abnormal sensations other than pain in their healed burns were experienced and reported by 82% of the patients (85 of 104). Table 2 lists the paresthetic sensations reported and the relative frequency of occurrence (76 of patients). Twenty-three of the 104 participants were interviewed between I and 2 yr after the accident, 33 between 2 and 3 yr, 26 between 3 and 4 yr, and 22 more than 4 yr postburn. In each group, the percentage of patients who complained of sensory abnormalities WWS
, and
tivel
type” of
91
c-
is
in mare than one area, they were asked to describe the site where the sensation was the strongest. Mare than half of the patients (49 of the paresthetic sen85, or 58%) reported ha e the others (36 of sations on a daily basis 85, or 42%) described them as intermittent. In terms of she intensity af the sensations, the mean score of the patients (N = 85) was 62 2 2.1 on a O-10 scale, where 0 indicated “not at all” and IO “extremely.” Certain types of weather or changes in the weather were cornmanly reported to trig r the sensations or I?lik2 them worse. Other increasing factors in,-
Work
Sleep
~~~~~2
K
of ~~~~st~~ti~ Sensations ___. _
Tingling
Stiffness ~~l~lfre~~i~~ Numbness Warmth
Pins and needles Elsclric shock Other (cramp, itching, etc.)
prims
7;
601104 541104 441104 341104 27/ IO4
58 52 42 33 26
24IIO4 14/104 14/104
23 13 13
cluded mobiliaarion, i’nmobiliza~ion, ‘r’echanical pressure, and fatigue.
Starislical illlillJW!4 were carried oul lo itle’iril’y some fi’ctors thar may he associated wit ii an increased risk of ~evel~~i~~~ painful or parest hetic sensations in healed burns. Two-tailed t tests or x’ analyses were performed to compare Ihe patients with and without sensory problems on various demographic and medical factors. Dtmo~aj?d~ic AUriButes The age or sex of ‘he
patients was not a significam predictor of pain in healed burns. The same was true for the different types of paresthetic sensation listed in Table 2 (P > .05). Characteristics qf the Bums
Wherher the patients had undergone a thermal or electrical burn was not significandy associated wirh the prevalence of pain or paresthesias in the scars. In contrast, the size of the burn (percent of total body surface area burned) was associated with certain types of sensory problems: Patients complaining of chronic pain (N = 36) had undergone more extensive burn injuries on the average (mea” = 24.6 2 19.4%) than those who did not report any pain (N = 68; mean = 16.2 f 12.2%) (1 = 2.35, P < .02). Stiffness and “pins and needles” types of sensation were also significantly more frequent in patients with more extensive injuries (stiffness: 1 = 2.73, P < ,008; pins and needles: 1 = 2.33, P < .03). Treatment
were also reported
frcquenrIy in grafred wou’&
Pmportioll of Type of sensations
.001). I‘ing%ing sensarions,
stiffness
Deep burn injuries that required skin grafts were associated with a significantly higher prevalence of chronic pain than superficial burns that healed spontaneously (x” = 13.8,
P =z .001).
numbness, a& si~~l~~ca~~~~more
(x2 = B5.7-42.1,
Other ty es of paresthrlic
srnsati0r-1
listed in Table 2 we no’ significantly more frequent in grafted than in nongrafted areas. Le&h of Tilne Elc$sed Since the Iujury A x2 analysis of the data presented on Figure 1 revealed no significant relationship between the presence of pain in the healed burns and the lengrh of time elapsed since the il?jury. Similarly, the prevalence of the differen’ types of’ paresthetic SC!llSiltiOl~ \VilS IMll fOUlKl IO Vi\r)i as ;I f’mction of Ihe nll~nber of years pos’burn.
‘I’he resulu show rhal abnormal sc~~s;lliol~s in healed burns are a co’n’no” phenomenon. 01’ the 104 patients interviewed 1 yr or more after their accident, ‘nore than 80%) reported parestl’e’ic sensations and 35% co‘nplained of pain. Further analyses revealed that these problems do nor necessarily disappear as time passes. Pain and paresthesias can persist f’or many years after the ir’jury, may be present every day, anti can interfere with the paticnl’s acrivities such as work, sleep, and social Me. The study confirms earlier observations’” tha’ the prevalence of sensory problems in healed burl’s is no1 relaled In ll’e age or sex of Ihe [Xlti~llt!+, or to the etiology of due burn. ever, the size of the burn was found to be a significant predict.or. Apparently, she more extensive rhe burn injury, the more likely ir is lhai the patient will develop chronic pain or paresburn injuries thetic sensations. Furthermore, that require skin grafting, as opposed to those that healed spontaneously, are associated with an increased risk of developing chronic sensory problems. The mechanisms involved in the development of pain and pareslhesias in healed burns are not known. It is possible that the sensations are due to some abnormalities in regeuerared nerve endings or to a deficient reinnervation ofi the scarred tissue, that may give rise to ahnormal inpUts.5-7*“’ Similar phenomena have brrn observed in other types of injury with damage fo peripheral nerves.‘d,H D&d obtained in the present study are subject
In spite of the above limitations, the results of the present study are believed to have important clinical implications. The observation that a substantial number of burn patients complain of chronic sensory problems in their healed injuries should stimulate other studies on this issue. More research must be done to document the phenomenon and thereby provide compensation agencies with ~~~~t~t~t~tiv~infortn~tio~ about the chronic sensory difficulties af burn victims. This should i~~~~~~vethe ~uidetitl~s for ~V~~~~~i~~~~~a at‘ i~~~~~~~irt~~~~~t in these ~~tti~t~ts. It would also be interesting to determine whether the s~~~~eet~ves~~~s~~t~o~~s r~pnrted by burn patients ore assockttedwith objective signs at’ aensory deficits in cutaneous sensitivity (c+_, detailed tactile ttnd ~t~~~~l~~~t~~~i~l~~ ot” with qu;mtifiable ;m*malies in scar tissue (f,p,, hy pertrophic scars, contractures, etc.), Seventl st~dies~~y~l~,i?~ have shewn ~rt~~~tt~et~tde~cits itI cutaneous sensitivity in burn patients, but none of them have ~t~~~~stj~~tte~ the r~~~~t~onsl~il~ between these deficits and s~tbJectiv~ sensory complait1ts. ~j~~~l~~, ways ta prevent OF ~~~t~~~ these problems ntxd ta be e~l~lore~. Well~desi spective studies should be cttrried aut to further d~tert?~it~~ the factors that may p~disp~~se or ~~~t~trjbnt~to the development of sensory abnor~~~~~~~1~~~in II itjuries. The results help to ide the target p~p~~l~tio~~an vent or reduce lung-term adverse effects injuries.
We are grateful to all the patients and to the staff of the medical records services af the Hot~l-Diets ~~sp~~l of Montreal and the Montreal General Wospitai, whose collaboration made this research possible. Thanks are i&o due to Mrs. Johattt~e bourgeois and to Mrs. Anita Pelletier for their valuable assistance in collecting the data. Finitlly, we appreciate Mrs. Jocelyne Fortin’s and Ms. Denise De~a~ins’s helpful technical assistance in preparing this manuscript. This work was supported by a grant from the F~~t~~~t~~~t~ de ~~~tel-Die~~ de ~n~~tr~~l (Fends des BriilCs) to Dr. M. ChainKre and by a grant (~A~~~l) from the Natural Sciences and Engitle~ring Research Council of Canada to Dr. R. Melzack.
a) In the area(s) of your body which have been burned there khoIXlilt 01‘ unusual sensa&)ns which iLIp ml Typt! of Sf3lSi\tiOll singling WUSilliOll “pins and needles” numbness cold-freezing sensation warm sensation electric shock stbusaliou sriffness trlhcr ,~~ _-m-
(strongest
specify
if tefi or right side
BIG _---
----r_pe__il_______l --.~___~____ *mm__.“.--.
it1 terms of (Exclude
steep hr)
sensalion)
a) If you were asked to rate the intensity at all” and “IO” indicates “extremely.” this sensation? b) What causes
site(s), are
Site
How often do you have this sensaticm *N of days/ma *N of hr/day Inlet&y
or which have been used as donor painful:
of this
sensation which uumber
OII a “0” 10 ” IO” scale where “0” iuctic2~es “no1 would you choose lo describe rhr inteusi[y o!’
this sensation or makes it worsr?
Painful Sensatim Site
a) In the area(s) of your body which there anywhere you feel pain? I = yes 0 = 110
have been burued
b) If yes, name
if’ left or right side:
c) If there Duration
specify
is more than one area,
(most painful
How often Number Number
all the areas;
or which have been
which area is the most painful?
used as clcmor sile(s), is
_
sile)
do you have this pain in terms of
of dayslmo of hrklay
(k~xclude sleep 111.)
AppendiseI (Conthed) Structured Interuh Protocol ftttensi$u (most painful
site)
If you were asked to rate the intensity of your pain on a “0” to “lo” scale where “0” indicates “no pain” and “10” jndicates “the worst pain imaginable ” which number would you choose to describe the intensity
of your pain when it is
* at its worst * at its least *
:4t
What
its usual level C;SUSCR
your
pain or makes it worse?
1, Subcommittee un Taxonomy of the Inttrnatit~nal Ass&don for the Study of Pain. Classiliration of chronic pain--Descriptions of chmnic pain ryndrumes and deRnitianr\ of pain terms, Pain I!lHri: Pl(auppl):S916-S221.
3. Melnaek R, Wall PD. The challenge of pain, 2nd 4. Ckoini&re M. The pain of burns. In: Wall PD. M&ack R, eds. Textbook of pain, ?nd ed. London: ChuKhill Livingstone. 19$9:4Q2-408. 5. Hermanson A,Jonsson CE, Lindblom U. Scnsibility after burn injury. Clin Physiol 1%?86:6:~07-59 1. 6. Pruitt RA, ‘The burn patient: II Later care and mmpiientions d thermal i$ry. Current Problems in Surgery 1979; lti: I-!13.
8. Lane PR, Hogan DJ, Chronic pain and scarring cement burns. Arch Dermatol 1985;121: 69.
r3. M&ride M. The fire that would not die. Palm Springs: FTC Publications, 1979. 10. Ton ‘I’E. The flames shall not Consume you. Blgin: David C. Cook, 1984. 11. Marvin JA, Heimbark DM. Pain control during the intensive care phase of burn care. Crit Care Clin 1985; I :G I-G& 12. Marvin JA. 1Ieimback DM. Pain management. ln: Fisher SV. Helm PA, eds, Comprehensive r&abilitation of burns, Baltimore: Williams and Wilkins. 198453 11-329. 13. Knudson-Cooper M. What are the research priorities in the behavioral areas for burn patients? J of Trauma 1!~84;24(suppl): 197-200. 14. Ward RS. Saffle JR, Schnebly A, et al. Sensory loss over grafted areas in patients with burns. J Burn Care Rehabil i989;10:536-538. 15. Papillon J. Personal communiciition. 16. American Medical Association. Guide to evaluation of permanent impairment, 3rd ed. Chicago: America1 Medical Association, 1988. 17. Commission de la Sante et de la S&uritt? au Travail, Rtglcment Annoti sur le Bar&medes Dommages Curpurels, Qu&ec. Canada: Commission de la Sante et de la S&wit& au Travail, 1987. 18. Knaysi CA, Crikelair GF, Cosman B. The rule of nines: Its history and accuracy. Plast Reconstr Surg 1968:4 13560-563. 19. Ponten B. Grafted skin. Acta Chir Stand 1960; 257(suppl): l-78.
pain,
paresthesia,
bunt
Most of the literature on burns is devoted to the problems encountered during the hospitalization phase. Very little empirical datil exist on the long-term effects of burn il!juries. ‘I’he presence of chronic PilinfUl or paresrlwt ir:* sensations’ in the healed wounds sl~ould not be surprising in view of Ihe fact Ihat the injury often Address reprint requests to: Manon
ChoiniPre, Phi), Burn Centre, Hotel-Dieu Hospital of Montreal, 3810 St-Urbain, Montreal, Quebec, Canada, H2W 1’1’8. Acceptedfor publication: April 8. I99 I. wl’he term “paresthetic” is used to refer to a nonpainful abnormal sensation. This definition is consistent with the recommendations of the Subcommittee on Taxonomy of the International Association for the 0 U.S. Cancer Pain Relief Committee. 1991 Published by Elsevier, New York. New York
involves dcslruction of nerve receptors iIlld fihers. Neuralgia is conn~u~nly repork~l in other types of injury involving damage to periphera! nerves.“.” Furthermore, these patients undergo repeated, complex surgical treatments, such as skin grafting, and many develop hypertrophic scars or contracn.ue~, any of which may be potential
causes
of’ pcrsislent
pain
and
paresthe-
sias.“-7
Lane and Hogen, ’ McBride,” and Ton”’ have anecdotal reports of chronic pain or paresthesia in healed burns, but the problem is provided
Study of Pam. It is recommended that the term “}~itresthesi;l” be used I0 dcscribe an abnormal scnsaLion which is not unpleasant while lhc term “tlyscsthcsia” should be employed prcfcrcntially fin an abnormal
sensarion which is unpleasant.
Choinikre et al.
-138
poorly documented in the literature. On the basis of their clinical experience, Marvin and Heimbach”*” maintain that only a minority of burn patients complain of pain after COtnpkte scar maturation. However, cases may go undiagnosed because they coincide with postinjury depression syndrome,” and a large number of patients are lost to follow-up because of the long-term nature of the recovery process.13 Therefore, it is possible that the prevalence of chronic sensory problems has been underestiwtatetl in burn patients. A recent study tends to support this hypothesis. During ~XiU1\itNith Of ~utaix~i~s sensitivity after grafting, Ward id colleagues’” noticed il Whtllid proportion of patients who complained of neuralgic problems: 25% of the examined patients (N = 60) rcported p”irr in the grafted iINXl!J, 25% had an inchronic prurirus, and 50% rcprtcd CltiWXi sensitivity to temperature, Further studies are clearly needed to document the long-term effects of burn injuries. The lack of quantitative information about this issue often produces difficulties for both patients and physicians, both of whom sesk to have these incapacities acknowledged by com“3” For example, although I4 described patients who experienced difficulty in returning to outdoor work because of intolerance to extremes of tetuperature, no mention is made of the specific sensory difficulties encountered by burn victims in the guidelines for evaluation of pwmanem ‘rment that are published by compensation ii?s (e.g., The American Medical Associaand the C~ommissisn de ia SantC et de la S&uritC au Travait”). The present study was dcsi fled 10 dwument he
pmvaknee
and
cha
sties of pain and p of patients with t may contribute to the development of these problems were also mplnrecl by examininfi: the intfuencc of vari&des such RS the patients’ demographic attributes, the characteristics of the burn injuries, the t~quired treatment, and the length df time since injury.
paresthesia problems in heakd burns. Factors
Journal of Pain and Symptom Management
Dieu Hospital of Montreal (N = 73) or at the Montreal General Hospital (N = 3 1) between April 198 1 and March 1987. The subjects were recruited from a list of consecutive admissions during this period by using a procedure that ensured that the names of the patients were not released to the investigators unless the patient
expressly granted permission. The medical record offices prepared a list of patients that excluded those who were deceased or who were classified as psychiatric patients. Then a letter was smt to each candidate by a staff member of the hospital who was assigned to patient recruitment for the present study. The letter ex-
plained the study requirements, and was nccompanied by a response card and a stamped rnvolope to be returned to the person in charge of patient recruhment. This persat~ compiled a list of volunteer participants (names. addresses, and phone numbers) and gave it to a specially trained research assistant, who then contacted each patient. Of the 379 candidates identified by the medical records offices, 295 were located and contacted by mail. One hundred and thirty-four (46%) consented tu p:lrticipate in the study, 15 (5%) refused, and 145 (49%) did not atwm.
Thirty patients were escluded during the course of the study for various reasons (inability to ~~~~~~~~~ll~~~~~te hecause of language or ability, presence of a disorder affecting functions such as diabetic neuropathy. cessive unavailability for the interview), ;I subsample of 104 participants (35%).
we Data were collected using structured telephone interviews. Many patients lived outside of the Montreal area, and telephone interviews, as opposed to written questionnaires, were considered to be the most appropriate and reliable method to carry out data collection in the context of the present exploratory study. All tele-
phone interviews were performed by two experienced, master’s level research assistants. Each
assistant was extensively trained by one of the investigators (MC.). This training ensured a standardized and uniform utikation of the structured
subjects were 10-l adult patients who had pitakd for burn injuries at the Hotel-
mental sensory or sucleaving
interview
protocol,
and frequent
meetings were organized to review and discuss the completed questionnaires. During the interview, the patients were asked
eir healed woun1ds. protocol was Conap’BS
At the end of the study, all the patients’ medical charts were reviewed I.0 collect infi~rmation about the characteristics of the burns (etij.llogy, size, location). Burn size (secoI1d- ;uid third-drgree burns) was calculated by using the Rule of Nines,” and was expressed as the perceljtitge of total body surface area burned. ‘l’he type cl{‘ treatment carried oul (e.g., skin grafi) and the length of time elapsed since IPW injury werr also recorded.
When
the
104 interviewed
cotnpao~ed with
the
275
lrarticip;rnts nanintervicwed
wc~rc pa-
found with respect. to age (II - 0.65, P > .05)* sex (x2 ” .03, P > .05) and extent of the burn injuries (I = 0.34, P > .OS). The demographic and medical characteristics of the subsample of participants (N = 104) are summarized in Table 1. tients,
no
significant
Pain Smalim
dilf+rcnce
in
was
Ifeahd Bumzs
Prevalence Thirty-six of the 104 participants, i.e., 35% of the sample, reported pain in the healed burns. All patients were interviewed at least 1 yr or more after their injury (mean
ChoinDre et al.
/
Journal of Pain and SymptomMnnagtvnent
/’
_’
100
60
a&
(0 - not at all, 4 = extremely)
in
is displayed
common in burn patients even many years after the accident.
Bum
~~~~p~~t~~t~~~ When patients had paresthesias
F~&FM Abnormal sensations other than pain in their healed burns were experienced and reported by 82% of the patients (85 of 104). Table 2 lists the paresthetic sensations reported and the relative frequency of occurrence (76 of patients). Twenty-three of the 104 participants were interviewed between I and 2 yr after the accident, 33 between 2 and 3 yr, 26 between 3 and 4 yr, and 22 more than 4 yr postburn. In each group, the percentage of patients who complained of sensory abnormalities WWS
, and
tivel
type” of
91
c-
is
in mare than one area, they were asked to describe the site where the sensation was the strongest. Mare than half of the patients (49 of the paresthetic sen85, or 58%) reported ha e the others (36 of sations on a daily basis 85, or 42%) described them as intermittent. In terms of she intensity af the sensations, the mean score of the patients (N = 85) was 62 2 2.1 on a O-10 scale, where 0 indicated “not at all” and IO “extremely.” Certain types of weather or changes in the weather were cornmanly reported to trig r the sensations or I?lik2 them worse. Other increasing factors in,-
Work
Sleep
~~~~~2
K
of ~~~~st~~ti~ Sensations ___. _
Tingling
Stiffness ~~l~lfre~~i~~ Numbness Warmth
Pins and needles Elsclric shock Other (cramp, itching, etc.)
prims
7;
601104 541104 441104 341104 27/ IO4
58 52 42 33 26
24IIO4 14/104 14/104
23 13 13
cluded mobiliaarion, i’nmobiliza~ion, ‘r’echanical pressure, and fatigue.
Starislical illlillJW!4 were carried oul lo itle’iril’y some fi’ctors thar may he associated wit ii an increased risk of ~evel~~i~~~ painful or parest hetic sensations in healed burns. Two-tailed t tests or x’ analyses were performed to compare Ihe patients with and without sensory problems on various demographic and medical factors. Dtmo~aj?d~ic AUriButes The age or sex of ‘he
patients was not a significam predictor of pain in healed burns. The same was true for the different types of paresthetic sensation listed in Table 2 (P > .05). Characteristics qf the Bums
Wherher the patients had undergone a thermal or electrical burn was not significandy associated wirh the prevalence of pain or paresthesias in the scars. In contrast, the size of the burn (percent of total body surface area burned) was associated with certain types of sensory problems: Patients complaining of chronic pain (N = 36) had undergone more extensive burn injuries on the average (mea” = 24.6 2 19.4%) than those who did not report any pain (N = 68; mean = 16.2 f 12.2%) (1 = 2.35, P < .02). Stiffness and “pins and needles” types of sensation were also significantly more frequent in patients with more extensive injuries (stiffness: 1 = 2.73, P < ,008; pins and needles: 1 = 2.33, P < .03). Treatment
were also reported
frcquenrIy in grafred wou’&
Pmportioll of Type of sensations
.001). I‘ing%ing sensarions,
stiffness
Deep burn injuries that required skin grafts were associated with a significantly higher prevalence of chronic pain than superficial burns that healed spontaneously (x” = 13.8,
P =z .001).
numbness, a& si~~l~~ca~~~~more
(x2 = B5.7-42.1,
Other ty es of paresthrlic
srnsati0r-1
listed in Table 2 we no’ significantly more frequent in grafted than in nongrafted areas. Le&h of Tilne Elc$sed Since the Iujury A x2 analysis of the data presented on Figure 1 revealed no significant relationship between the presence of pain in the healed burns and the lengrh of time elapsed since the il?jury. Similarly, the prevalence of the differen’ types of’ paresthetic SC!llSiltiOl~ \VilS IMll fOUlKl IO Vi\r)i as ;I f’mction of Ihe nll~nber of years pos’burn.
‘I’he resulu show rhal abnormal sc~~s;lliol~s in healed burns are a co’n’no” phenomenon. 01’ the 104 patients interviewed 1 yr or more after their accident, ‘nore than 80%) reported parestl’e’ic sensations and 35% co‘nplained of pain. Further analyses revealed that these problems do nor necessarily disappear as time passes. Pain and paresthesias can persist f’or many years after the ir’jury, may be present every day, anti can interfere with the paticnl’s acrivities such as work, sleep, and social Me. The study confirms earlier observations’” tha’ the prevalence of sensory problems in healed burl’s is no1 relaled In ll’e age or sex of Ihe [Xlti~llt!+, or to the etiology of due burn. ever, the size of the burn was found to be a significant predict.or. Apparently, she more extensive rhe burn injury, the more likely ir is lhai the patient will develop chronic pain or paresburn injuries thetic sensations. Furthermore, that require skin grafting, as opposed to those that healed spontaneously, are associated with an increased risk of developing chronic sensory problems. The mechanisms involved in the development of pain and pareslhesias in healed burns are not known. It is possible that the sensations are due to some abnormalities in regeuerared nerve endings or to a deficient reinnervation ofi the scarred tissue, that may give rise to ahnormal inpUts.5-7*“’ Similar phenomena have brrn observed in other types of injury with damage fo peripheral nerves.‘d,H D&d obtained in the present study are subject
In spite of the above limitations, the results of the present study are believed to have important clinical implications. The observation that a substantial number of burn patients complain of chronic sensory problems in their healed injuries should stimulate other studies on this issue. More research must be done to document the phenomenon and thereby provide compensation agencies with ~~~~t~t~t~tiv~infortn~tio~ about the chronic sensory difficulties af burn victims. This should i~~~~~~vethe ~uidetitl~s for ~V~~~~~i~~~~~a at‘ i~~~~~~~irt~~~~~t in these ~~tti~t~ts. It would also be interesting to determine whether the s~~~~eet~ves~~~s~~t~o~~s r~pnrted by burn patients ore assockttedwith objective signs at’ aensory deficits in cutaneous sensitivity (c+_, detailed tactile ttnd ~t~~~~l~~~t~~~i~l~~ ot” with qu;mtifiable ;m*malies in scar tissue (f,p,, hy pertrophic scars, contractures, etc.), Seventl st~dies~~y~l~,i?~ have shewn ~rt~~~tt~et~tde~cits itI cutaneous sensitivity in burn patients, but none of them have ~t~~~~stj~~tte~ the r~~~~t~onsl~il~ between these deficits and s~tbJectiv~ sensory complait1ts. ~j~~~l~~, ways ta prevent OF ~~~t~~~ these problems ntxd ta be e~l~lore~. Well~desi spective studies should be cttrried aut to further d~tert?~it~~ the factors that may p~disp~~se or ~~~t~trjbnt~to the development of sensory abnor~~~~~~~1~~~in II itjuries. The results help to ide the target p~p~~l~tio~~an vent or reduce lung-term adverse effects injuries.
We are grateful to all the patients and to the staff of the medical records services af the Hot~l-Diets ~~sp~~l of Montreal and the Montreal General Wospitai, whose collaboration made this research possible. Thanks are i&o due to Mrs. Johattt~e bourgeois and to Mrs. Anita Pelletier for their valuable assistance in collecting the data. Finitlly, we appreciate Mrs. Jocelyne Fortin’s and Ms. Denise De~a~ins’s helpful technical assistance in preparing this manuscript. This work was supported by a grant from the F~~t~~~t~~~t~ de ~~~tel-Die~~ de ~n~~tr~~l (Fends des BriilCs) to Dr. M. ChainKre and by a grant (~A~~~l) from the Natural Sciences and Engitle~ring Research Council of Canada to Dr. R. Melzack.
a) In the area(s) of your body which have been burned there khoIXlilt 01‘ unusual sensa&)ns which iLIp ml Typt! of Sf3lSi\tiOll singling WUSilliOll “pins and needles” numbness cold-freezing sensation warm sensation electric shock stbusaliou sriffness trlhcr ,~~ _-m-
(strongest
specify
if tefi or right side
BIG _---
----r_pe__il_______l --.~___~____ *mm__.“.--.
it1 terms of (Exclude
steep hr)
sensalion)
a) If you were asked to rate the intensity at all” and “IO” indicates “extremely.” this sensation? b) What causes
site(s), are
Site
How often do you have this sensaticm *N of days/ma *N of hr/day Inlet&y
or which have been used as donor painful:
of this
sensation which uumber
OII a “0” 10 ” IO” scale where “0” iuctic2~es “no1 would you choose lo describe rhr inteusi[y o!’
this sensation or makes it worsr?
Painful Sensatim Site
a) In the area(s) of your body which there anywhere you feel pain? I = yes 0 = 110
have been burued
b) If yes, name
if’ left or right side:
c) If there Duration
specify
is more than one area,
(most painful
How often Number Number
all the areas;
or which have been
which area is the most painful?
used as clcmor sile(s), is
_
sile)
do you have this pain in terms of
of dayslmo of hrklay
(k~xclude sleep 111.)
AppendiseI (Conthed) Structured Interuh Protocol ftttensi$u (most painful
site)
If you were asked to rate the intensity of your pain on a “0” to “lo” scale where “0” indicates “no pain” and “10” jndicates “the worst pain imaginable ” which number would you choose to describe the intensity
of your pain when it is
* at its worst * at its least *
:4t
What
its usual level C;SUSCR
your
pain or makes it worse?
1, Subcommittee un Taxonomy of the Inttrnatit~nal Ass&don for the Study of Pain. Classiliration of chronic pain--Descriptions of chmnic pain ryndrumes and deRnitianr\ of pain terms, Pain I!lHri: Pl(auppl):S916-S221.
3. Melnaek R, Wall PD. The challenge of pain, 2nd 4. Ckoini&re M. The pain of burns. In: Wall PD. M&ack R, eds. Textbook of pain, ?nd ed. London: ChuKhill Livingstone. 19$9:4Q2-408. 5. Hermanson A,Jonsson CE, Lindblom U. Scnsibility after burn injury. Clin Physiol 1%?86:6:~07-59 1. 6. Pruitt RA, ‘The burn patient: II Later care and mmpiientions d thermal i$ry. Current Problems in Surgery 1979; lti: I-!13.
8. Lane PR, Hogan DJ, Chronic pain and scarring cement burns. Arch Dermatol 1985;121: 69.
r3. M&ride M. The fire that would not die. Palm Springs: FTC Publications, 1979. 10. Ton ‘I’E. The flames shall not Consume you. Blgin: David C. Cook, 1984. 11. Marvin JA, Heimbark DM. Pain control during the intensive care phase of burn care. Crit Care Clin 1985; I :G I-G& 12. Marvin JA. 1Ieimback DM. Pain management. ln: Fisher SV. Helm PA, eds, Comprehensive r&abilitation of burns, Baltimore: Williams and Wilkins. 198453 11-329. 13. Knudson-Cooper M. What are the research priorities in the behavioral areas for burn patients? J of Trauma 1!~84;24(suppl): 197-200. 14. Ward RS. Saffle JR, Schnebly A, et al. Sensory loss over grafted areas in patients with burns. J Burn Care Rehabil i989;10:536-538. 15. Papillon J. Personal communiciition. 16. American Medical Association. Guide to evaluation of permanent impairment, 3rd ed. Chicago: America1 Medical Association, 1988. 17. Commission de la Sante et de la S&uritt? au Travail, Rtglcment Annoti sur le Bar&medes Dommages Curpurels, Qu&ec. Canada: Commission de la Sante et de la S&wit& au Travail, 1987. 18. Knaysi CA, Crikelair GF, Cosman B. The rule of nines: Its history and accuracy. Plast Reconstr Surg 1968:4 13560-563. 19. Ponten B. Grafted skin. Acta Chir Stand 1960; 257(suppl): l-78.