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THE INTERRELATION OF PERSONALITY AND POSTOPERATIVE FACTORS
Br. J. Anaesth. (1977), 49,259
THE INTERRELATION OF PERSONALITY AND POSTOPERATIVE FACTORS P. BOYLE AND G. D. PARBROOK SUMMARY
In a series of four trials, patients undergoing upper abdominal operations have been studied to ascertain the interrelationships between psychological factors on the one hand and postoperative pain and the requirements for postoperative analgesia on the other (Dalrymple, Parbrook and Steel, 1973; Parbrook, Steel and Dalrymple, 1973; Dalrymple and Parbrook, 1976; Henderson and Parbrook, 1976). Although the aims of each component trial of the series varied slightly, the basic pattern remained comparable, in that the patients' personality was assessed before operation and changes after operation, including measurements of vital capacity, were noted. In the present paper a statistical analysis of the overall data is presented as it was felt that the greater numbers available for analysis would permit clarification of the underlying trends in the relationships between personality and other factors in these patients. In particular it was hoped to evaluate personality assessment as a screening procedure to identify those patients who are most likely to have severe pain or marked vital capacity impairment in the period after surgery. METHODS
Full details of the methods used were described in previous papers, but a review of the details of the personality assessment is presented here. The patients were visited on the day before surgery and each patient's personality was assessed using a PEN PETER BOYLE, B . S C , Hospital Health Services Research Unit, Department of Medicine, Western Infirmary, Glasgow
Gl 16NT.
GEOFFREY
D.
PARBROOK,
M.D.,
F.F.A.R.C.S., University Department of Anaesthesia, Glasgow Royal Infirmary, Glasgow G4 OSF.
inventory. This is the most recent of a series of questionnaires developed by Eysenck and Eysenck (1969). In it, the patient has to answer 78 questions, YES or NO, and, by checking the form against a key, four psychological features are assessed. The factors, together with their range of scores, are: Neuroticism (0-20). This measures emotional stability and the smaller the value the more stable the personality involved. Extroversion (0-20). This reflects the patient's sociability, ranging from the highly introverted (with low readings) to the highly extroverted. Psychoticism (0-20). This assesses the tendency to psychotic traits in the patient. Lie (0-18) measures the patient's tendency to exaggerate. Some earlier workers have eliminated individual results on the basis of a high lie score but, as suggested by Knowles and Kreitman (1965), we have incorporated all results and analysed the lie score as a separate factor. In all our trials, vital capacity was measured before operation and other general details were noted, such as age, occupation (social class) and smoking habits. Assessment after operation In all the trials vital, capacity was measured 24 h after surgery and the vital capacity impairment was calculated. In addition to providing an objective index of the patient's pain, it was postulated that a high degree of impairment of vital capacity would be associated with an increased incidence of pulmonary complications after surgery. In three of the four trials subjective measurements of the patient's pain were made using a visual analogue scale. This consists of a 10-cm line on which the zero reading represents no pain and the 10-cm reading represents maximum
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A composite statistical analysis was made of the results from four trials comprising patients undergoing upper abdominal operations. It revealed a marked correlation between the neuroticism score as measured by a personality inventory before operation and the percentage vital capacity impairment found after operation. Neuroticism correlated also with pain as measured by a visual analogue scale. The vital capacity impairment and subjective pain readings were interrelated and both neuroticism and vital capacity impairment were related to the chest complication rate. Personality assessment before operation can identify one group of patients who will have marked pain and limitation of vital capacity after operation.
260
BRITISH JOURNAL OF ANAESTHESIA
pain. In all cases chest complications were noted after surgery using a scoring system based on the following factors: Pyrexia (temperature greater than 37.5 °C) persisting for more than 48 h New or increased cough New or increased sputum production Positive bacteriological culture of the sputum Antibiotic therapy administered for chest complications by the surgical staff Each of these factors scored one point in the chest complication score.
Psychologicalfactors and postoperative changes
RESULTS
There were 190 patients in the four trials and table I shows the results of the correlation analysis for each trial individually and also for all the males (140) and for the whole sample (190). Not all the variables could be used in the correlation analysis because some of a discrete nature took only a few possible values. The more important results will be considered in greater detail.
TABLE I. General results of correlation analysis
Trial 2
Trial 3
Trial 4
Male
Female
Male
Male
X X X
X X
(0.1
P<0.05 X
P<0.05
50 Ulcer
140 Ulcer
40 Ulcer
X
X
P< 0.001 P<0.01
P<0.05 (0.1
X X
(-ve) P<0.01 X X X
P<0.05 X X
X
Not available
X
P< 0.001 P<0.01 P< 0.001 P<0.01 X X X X
50 Gallbladder
X X X X
50 Number in trial Operation Ulcer Neuroticism (N) v. X Extroversion X Lie X Age VC imp. P<0.01 10 cm pain P< 0.001 Extroversion (E) v. ( + ve) P<0.05 Lie* X Age X VCimp. X 10 cm pain Lie (L) v. Age VC imp. 10 cm pain Age v. X VCimp. 10 cm pain X VC imp. v. 10 cm pain P< 0.001
All male
X X X
Not available P<0.05
P<0.01
X
Not available
X X
P<0.05 X
Not available
P<0.01
X
Not available
X
190 Both X
P< 0.001 P<0.01 P< 0.001 P< 0.001
P<0.01
X X
X X
X X
X X
P<0.05
* Trial 1—significant positive correlation; Trial 3—significant negative correlation. x Indicates a result which was not statistically significant. VC imp. = % Vital Capacity impairment (24 h after operation). In cases where a result has been just short of significance (0.1
All
X X X X
Trial 1
P< 0.001
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Neuroticism. There was an overall interrelationship between neuroticism and impairment of vital capacity, although this relationship was not found in some of the individual trials. A better overall picture is indicated by the scattergram (fig. 1) in which the data occupy a wedge, there being none in the lower right-hand section. The results indicated that, as the patients' neuroticism score increased, there was a steady increase in the minimum vital capacity impairment. Patients with an N score greater than 12 had in all cases an impairment of at least 50% at 24 h after operation. Thus a personality inventory before operation can provide an indication of the likely minimum vital capacity impairment at 24 h after operation. The overall results also provided a highly significant correlation between neuroticism and the subjective pain score using the 10-cm line system. Correlation analysis was not considered appropriate for the neuroticism score and chest complications as the latter took only six possible values. The patients were arranged in increasing order of neuroticism
PERSONALITY AND POSTOPERATIVE FACTORS % V.C. Impairment ( 24 hours )
lOO-i 80-
60 J
20-
I 12
16
I 20
FIG. 1. Distribution of vital capacity impairment according to neuroticism score.
score and the whole group divided into quarters for analysis of the chest complication scores (table II). The middle two groups were so similar that they were combined to give one group. Fifty-nine per cent
pain scores. An analysis of variance did not show any significant interrelationship between extroversion and the number of analgesic injections administered in the first 24 h after operation or between extroversion and the chest complication scores. Lie score and psychoticism. These psychological factors appeared less important in patients undergoing upper abdominal operations. In the study of female patients, lie score correlated with subjective pain readings, but this was not found in the three studies in male patients. The results might indicate that the women with higher lie scores tended to exaggerate their pain. Apart from this, lie scores did not correlate with other postoperative factors. The overall results showed also an interrelationship between neuroticism and lie scores, patients with high lie scores having high neuroticism scores. The psychoticism scores showed a marked asymmetrical distribution and consequently they were divided into groups for analysis: patients with a score of three and less and those with a score of more than three. There were no significant findings in the analysis of these scores other than a tendency for patients with a high P score to have a high N score.
Other factors influencing pain after operation Age. Age did not seem to be an important factor in influencing vital capacity impairment, although in one TABLE II. Neuroticism and chest complications trial (trial 3) vital capacity impairment appeared to be less in the older patients. This might have been lor 2 0 3, 4 or 5 related to the tendency of the neuroticism score of the chest chest chest patients to decrease with age. The lie score, on the complica- complica- complication tions tions other hand, increased with age. n (%) (%) (%) Social class. Social class was not measured in the female patients. In the male patients, the details for Low group 41 27 14 59 social class are provided in table III, with the results (N«5) 43 28 29 Medium group 72 of t tests for differences in vital capacity impairment 37 27 19 54 High group between each of the social class groups. It was found (N> 12) that patients in social class 4 had a significantly higher vital capacity impairment compared with those n = number of patients. patients in any other group. While those patients in of the patients with a neuroticism score less than 5 social class 3 had a significantly greater impairment had no complications while 14% had a chest complica- than those in social class 2, there were no other tion score of 3,4 or 5. In the case of the patients with significant differences. a high N score (N ^ 12) the proportions were reversed. Smoking habits. There was no correlation between The table suggests that patients with N score less a patient's smoking habits and the changes after than 5 were less likely to have complications, while operation. There was a correlation between smoking those with a high score of over 12 were particularly habits and neuroticism score: those patients who likely to have several complications following surgery. smoked more had a lower neuroticism score than Extroversion. The results did not indicate any light or non-smokers. Previous workers have found a interrelationship between extroversion scores and correlation between a low neuroticism score and lung neuroticism, vital capacity impairment or subjective cancer in male patients (Kissen and Eysenck, 1962).
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40-
261
BRITISH JOURNAL OF ANAESTHESIA
262 TABLE III. Vital Capacity impairment (VC imp.) of patients according to social class Mean 0/
la
VCimp. Social Social Social Social Social
class class class class class
1 2 3 4 5
0 10 55 41 34
60.9 67.2 71.8 63.2
SD
13.63 9.41 10.45 12.99
Mean* N score
SD
6.50 7.00 8.64 7.75
6.23 3.71 4.02 3.86
an increase of the mean vital capacity impairment from 55 to 80% over the range of the subjective pain assessment readings. In three of the trials the patients' vital capacity impairment was measured on the 6th day after operation also and the interrelationship between the 1st day and 6th day impairment of capacity is seen in figure 3. The vertical distance of the point from the x
=y
Social class 2 Social class 3 Social class 4 Social class 3 Social class 4 Social class 5
0.1
* There were no significant differences between the mean neuroticism scores for each of the social class groups. n = number of patients.
Interrelationship of postoperative details
There was an overall correlation between the patients' vital capacity impairment and the patients' subjective pain as assessed by the visual analogue scale (table I). Figure 2 illustrates the mean impairment for each pain score in these studies and indicates
60
80
100
Day 1
FIG. 3. Changes in vital capacity impairment from day 1 to day 6. The vertical distance of the readings from the line x = y measures changes in vital capacity impairment between 1st and 6th day after operation.
% V. C. IMPAIRMENT ( 2 4 HOURS )
100 T
80-
60-
40-
20-
I
10 Subjective Pain Assessment (0 - - • 10 ) FIG. 2. Mean impairment of vital capacity for each pain score.
x = y line (45° line) shows the change in vital capacity impairment between the two times. Although all patients except two showed a lessening of the vital capacity impairment over this period, there was a marked variation in the rate of improvement of the individual patients. An interrelationship was found between the 24 h vital capacity impairment and the chest complication scores (table IV). An analysis similar to that for neuroticism and chest complications was made, the patients being arranged in increasing order of vital capacity impairment and divided into four equal groups. The two middle quarters were again found to provide similar results in terms of chest complications, and were joined. The majority of the group of patients with the lowest vital capacity impairment (less than 58%) had no chest complications, and only 18% had complications scores of 3 or more. In the case of the patients with marked impairments of vital
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Results of t tests for differences in mean % VC imp.
263
PERSONALITY AND POSTOPERATIVE FACTORS TABLE IV. Vital Capacity impairment and chest complications 3, 4 or 5 0 lor 2 chest chest chest complica- complica- complications tion tions (%)
(%)
(%)
Low group 38 (imp. s= 58) Medium group 72 40 High group (imp. > 74)
66
16
18
42 17
28 37
30 46
n = number of patients. ACKNOWLEDGEMENTS
capacity (more than 74%) the incidence of complications was reversed as only 17% had no complications and 46% had scores of 3 or more. Statistical comparison was made of the vital capacity impairments of patients with the various complication scores and the impairment of the group of patients with no complications (score 0) was in every case significantly less (P<0.05) than that of patients with complications (scores 1, 2, 3 or 4). The results complete the link between neurotirism, vital capacity impairment and chest complications and indicate that these three factors are closely interrelated. DISCUSSION
The analysis of the greater number of data available in these four trials has provided a better indication of the interrelationship between neuroticism and postoperative factors than was possible with the individual trials. The results indicate that a marked impairment of vital capacity after operation can be expected in a patient with a high neuroticism score. In this way, by a test before operation, it is possible to predict a certain "problem group" of patients. These patients will warrant special attention, perhaps by more intense reassurance before operation (Egbert et al., 1964), by extradural block (Simpson et al., 1961) or by inhalation analgesia (Parbrook and Kennedy, 1964). It cannot be assumed that a patient with a low neuroticism score will have a smooth course after surgery, as there is a wide variation of the vital capacity impairment in these patients; consequently it is reasonable to suggest that neuroticism is only one of several factors which adversely affect the prognosis of a patient after surgery. Although the study only reveals associations and cannot provide the reason underlying the effects of the N scores, the interrelationship between N score,
Professor M. R. Bond is thanked for advice on psychological aspects of these studies and Mr A. D. McLaren for statistical supervision. Mr P. Boyle is currently supported by a grant from the Scottish Home and Health Department and the studies reported were supported by a grant from the Medical Research Council. REFERENCES
Dalrymple, D. G., and Parbrook, G. D. (1976). Personality assessment and postoperative analgesia. A study in male patients undergoing elective gastric surgery. Br. J. Anaesth., 48,593. Steel, D. F. (1973). Factors predisposing to postoperative pain and pulmonary complications. A study of female patients undergoing elective cholecystectomy. Br. J. Anaesth., 45,589. Egbert, L. D., Battit, G. E., Welch, C. E., and Bartlett, M. K. (1964). Reduction of postoperative pain by encouragement and instruction of patients. N. Engl. J. Med., 270,825. Eysenck, S. G. B., and Eysenck, H. J. (1969). Scores on three personality variables as a function of age, sex and social class. Br.J. Soc. Clin. Psychol, 8,69. Henderson, J. J., and Parbrook, G. D. (1976). Influence of anaesthetic technique on postoperative pain. A comparison of anaesthetic supplementation with halothane and with phenoperidine. Br.J. Anaesth., 48,587. Kissen, D. M., and Eysenck, H. J. (1962). Personality in male lung cancer patients. J. Psychosom. Res., 6,123. Knowles, J. B., and Kreitman, N. (1965). The Eysenck Personality Inventory—some considerations. Br. J. Psychiatr., 111,755. McColl, I., Drinkwater, J. E., Hulme-Moir, I., and Donnan, S. P. B. (1971). Prediction of success or failure of gastric surgery. Br.J. Surg., 58,768. Parbrook, G. D., and Kennedy, B. R. (1964). Value of premixed nitrous oxide and oxygen mixtures in the relief of postoperative pain. Br. Med.J., 2,1303. Steel, D. F., and Dalrymple, D. G. (1973). Factors predisposing to postoperative pain and pulmonary complications. A study of male patients undergoing elective gastric surgery. Br.J. Anaesth., 45,21. Simpson, B. R. J., Parkhouse, J., Marshall, R., and Lambrechts, W. (1961). Extradural analgesia and the prevention of postoperative pulmonary complications. Br. J. Anaesth., 33,628.
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n
pain, vital capacity impairment and chest complications suggests that a patient with a high neuroticism score will suffer more abdominal pain, that this leads to a splinting effect on the diaphragm and that a higher risk of chest complications will follow in consequence. In addition to the relationship of neuroticism to pain, other workers have shown that this factor is also related to the long-term prognosis after ulcer surgery (McColl et al., 1971). A routine personality check by means of an inventory will be of value in all patients scheduled for upper abdominal operations.
BRITISH JOURNAL OF ANAESTHESIA
264 INTER-RELATION DE LA PERSONNALITE ET DBS FACTEURS POST-OPERATOIRES RESUME
DIE WECHSELWIRKUNG VON PERSONLICHKEIT UND POSTOPERTIVEN FAKTOREN ZUSAMMENFASSUNG
Eine zusammengesetzte statistische Analyse der Resultate von vier Versuchen mit Patienten nach chirurgischen Eingriffen im oberen Abdomen wurde durchgefuhrt. Es ergab sich eine deutliche Wechselwirkung zwischen den vor der Operation durch Personlichkeitstests gemessenen neurotischen Werten und dem nach der Operation festgestellten Prozentsatz der Beeintrachtigung lebenswichtiger
LA INTERRELACION DE LOS FACTORES DE PERSONALIDAD Y DEL POSTOPERATORIO SUMARIO
Se efectu6 un analisis compuesto estadistico de los resultados de cuatro pruebas comprendiendo pacientes sometidos a operaciones del abdomen alto. Se revelo una marcada correlation entre la valoracion de neuroticismo medida segun un inventario de la personalidad antes de la operation y el porcentaje de disminuci6n de la capacidad vital que se hallo tras la operation. El neuroticismo tambien se correspondio con el dolor, medido mediante una escala analoga visual. Los valores para disminuci6n de capacidad vital y dolor sujetivos se hallaban interrelacionados y tan to el neurotitismo y la disminucion de capacidad vital estaban relacionados con el indice de complicationes toracicas. La evaluation de la personalidad preoperatoriamente puede identificar a un grupo de pacientes que padeceren marcado dolor y limitation de capacidad vital en el postoperatorio.
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On a fait une analyse statistique composee des resultats de quatre essais comprenant des malades subissant une intervention chirurgicale a la partie superieure de l'abdomen. Elle a revels une correlation marquee entre le score de nevrose, tel qu'on peut le mesurer par un inventaire de la personnalite avant l'operation et le pourcentage d'alte>ation de la capacite vitale existant apres l'operation. La neVrose 6tait egalement en correlation avec la douleur, tel qu'on peut la mesurer par une ichelle analogue visuelle. Les lectures de l'alt&ration de la capacite vitale et de la douleur subjective etaient inter-reliees et la nevrose et l'alteiation de la capacite vitale etaient reliees au taux de complication de la poitrine. L'evaluation de la personnalit6 avant Top^ration permet d'identifier le groupe de malades qui souffrira de douleurs prononcees et qui aura une restriction de la capacity vitale apres I'op6ration.
Funktionen. Diese neurotischen Werte zeigten auch eine Wechselbeziehung zu dem nach einer visuellen Analogskala gemessenen Schmerz. Die Beeintrachtigung lebenswichtiger Funktionen und die Messungen der subjektiven Schmerzen waren aufeinander bezogen, und sowohl diese Beeintrachtigung als auch die neurotischen Werte hatten einen Zusammenhang mit der Haufigkeit von BrustraumKomplikationen. Durch die Personlichkeitsbewertung vor der Operation kann eine Gruppen von Patienten bestimmt werden, bei der es nach der Operation zu starkeren Schmerzen und zu einer Beeintrachtigung lebenswichtiger Funktionen kommen wird.
THE INTERRELATION OF PERSONALITY AND POSTOPERATIVE FACTORS P. BOYLE AND G. D. PARBROOK SUMMARY
In a series of four trials, patients undergoing upper abdominal operations have been studied to ascertain the interrelationships between psychological factors on the one hand and postoperative pain and the requirements for postoperative analgesia on the other (Dalrymple, Parbrook and Steel, 1973; Parbrook, Steel and Dalrymple, 1973; Dalrymple and Parbrook, 1976; Henderson and Parbrook, 1976). Although the aims of each component trial of the series varied slightly, the basic pattern remained comparable, in that the patients' personality was assessed before operation and changes after operation, including measurements of vital capacity, were noted. In the present paper a statistical analysis of the overall data is presented as it was felt that the greater numbers available for analysis would permit clarification of the underlying trends in the relationships between personality and other factors in these patients. In particular it was hoped to evaluate personality assessment as a screening procedure to identify those patients who are most likely to have severe pain or marked vital capacity impairment in the period after surgery. METHODS
Full details of the methods used were described in previous papers, but a review of the details of the personality assessment is presented here. The patients were visited on the day before surgery and each patient's personality was assessed using a PEN PETER BOYLE, B . S C , Hospital Health Services Research Unit, Department of Medicine, Western Infirmary, Glasgow
Gl 16NT.
GEOFFREY
D.
PARBROOK,
M.D.,
F.F.A.R.C.S., University Department of Anaesthesia, Glasgow Royal Infirmary, Glasgow G4 OSF.
inventory. This is the most recent of a series of questionnaires developed by Eysenck and Eysenck (1969). In it, the patient has to answer 78 questions, YES or NO, and, by checking the form against a key, four psychological features are assessed. The factors, together with their range of scores, are: Neuroticism (0-20). This measures emotional stability and the smaller the value the more stable the personality involved. Extroversion (0-20). This reflects the patient's sociability, ranging from the highly introverted (with low readings) to the highly extroverted. Psychoticism (0-20). This assesses the tendency to psychotic traits in the patient. Lie (0-18) measures the patient's tendency to exaggerate. Some earlier workers have eliminated individual results on the basis of a high lie score but, as suggested by Knowles and Kreitman (1965), we have incorporated all results and analysed the lie score as a separate factor. In all our trials, vital capacity was measured before operation and other general details were noted, such as age, occupation (social class) and smoking habits. Assessment after operation In all the trials vital, capacity was measured 24 h after surgery and the vital capacity impairment was calculated. In addition to providing an objective index of the patient's pain, it was postulated that a high degree of impairment of vital capacity would be associated with an increased incidence of pulmonary complications after surgery. In three of the four trials subjective measurements of the patient's pain were made using a visual analogue scale. This consists of a 10-cm line on which the zero reading represents no pain and the 10-cm reading represents maximum
Downloaded from http://bja.oxfordjournals.org/ at University of California, Santa Barbara on July 2, 2015
A composite statistical analysis was made of the results from four trials comprising patients undergoing upper abdominal operations. It revealed a marked correlation between the neuroticism score as measured by a personality inventory before operation and the percentage vital capacity impairment found after operation. Neuroticism correlated also with pain as measured by a visual analogue scale. The vital capacity impairment and subjective pain readings were interrelated and both neuroticism and vital capacity impairment were related to the chest complication rate. Personality assessment before operation can identify one group of patients who will have marked pain and limitation of vital capacity after operation.
260
BRITISH JOURNAL OF ANAESTHESIA
pain. In all cases chest complications were noted after surgery using a scoring system based on the following factors: Pyrexia (temperature greater than 37.5 °C) persisting for more than 48 h New or increased cough New or increased sputum production Positive bacteriological culture of the sputum Antibiotic therapy administered for chest complications by the surgical staff Each of these factors scored one point in the chest complication score.
Psychologicalfactors and postoperative changes
RESULTS
There were 190 patients in the four trials and table I shows the results of the correlation analysis for each trial individually and also for all the males (140) and for the whole sample (190). Not all the variables could be used in the correlation analysis because some of a discrete nature took only a few possible values. The more important results will be considered in greater detail.
TABLE I. General results of correlation analysis
Trial 2
Trial 3
Trial 4
Male
Female
Male
Male
X X X
X X
(0.1
P<0.05 X
P<0.05
50 Ulcer
140 Ulcer
40 Ulcer
X
X
P< 0.001 P<0.01
P<0.05 (0.1
X X
(-ve) P<0.01 X X X
P<0.05 X X
X
Not available
X
P< 0.001 P<0.01 P< 0.001 P<0.01 X X X X
50 Gallbladder
X X X X
50 Number in trial Operation Ulcer Neuroticism (N) v. X Extroversion X Lie X Age VC imp. P<0.01 10 cm pain P< 0.001 Extroversion (E) v. ( + ve) P<0.05 Lie* X Age X VCimp. X 10 cm pain Lie (L) v. Age VC imp. 10 cm pain Age v. X VCimp. 10 cm pain X VC imp. v. 10 cm pain P< 0.001
All male
X X X
Not available P<0.05
P<0.01
X
Not available
X X
P<0.05 X
Not available
P<0.01
X
Not available
X
190 Both X
P< 0.001 P<0.01 P< 0.001 P< 0.001
P<0.01
X X
X X
X X
X X
P<0.05
* Trial 1—significant positive correlation; Trial 3—significant negative correlation. x Indicates a result which was not statistically significant. VC imp. = % Vital Capacity impairment (24 h after operation). In cases where a result has been just short of significance (0.1
All
X X X X
Trial 1
P< 0.001
Downloaded from http://bja.oxfordjournals.org/ at University of California, Santa Barbara on July 2, 2015
Neuroticism. There was an overall interrelationship between neuroticism and impairment of vital capacity, although this relationship was not found in some of the individual trials. A better overall picture is indicated by the scattergram (fig. 1) in which the data occupy a wedge, there being none in the lower right-hand section. The results indicated that, as the patients' neuroticism score increased, there was a steady increase in the minimum vital capacity impairment. Patients with an N score greater than 12 had in all cases an impairment of at least 50% at 24 h after operation. Thus a personality inventory before operation can provide an indication of the likely minimum vital capacity impairment at 24 h after operation. The overall results also provided a highly significant correlation between neuroticism and the subjective pain score using the 10-cm line system. Correlation analysis was not considered appropriate for the neuroticism score and chest complications as the latter took only six possible values. The patients were arranged in increasing order of neuroticism
PERSONALITY AND POSTOPERATIVE FACTORS % V.C. Impairment ( 24 hours )
lOO-i 80-
60 J
20-
I 12
16
I 20
FIG. 1. Distribution of vital capacity impairment according to neuroticism score.
score and the whole group divided into quarters for analysis of the chest complication scores (table II). The middle two groups were so similar that they were combined to give one group. Fifty-nine per cent
pain scores. An analysis of variance did not show any significant interrelationship between extroversion and the number of analgesic injections administered in the first 24 h after operation or between extroversion and the chest complication scores. Lie score and psychoticism. These psychological factors appeared less important in patients undergoing upper abdominal operations. In the study of female patients, lie score correlated with subjective pain readings, but this was not found in the three studies in male patients. The results might indicate that the women with higher lie scores tended to exaggerate their pain. Apart from this, lie scores did not correlate with other postoperative factors. The overall results showed also an interrelationship between neuroticism and lie scores, patients with high lie scores having high neuroticism scores. The psychoticism scores showed a marked asymmetrical distribution and consequently they were divided into groups for analysis: patients with a score of three and less and those with a score of more than three. There were no significant findings in the analysis of these scores other than a tendency for patients with a high P score to have a high N score.
Other factors influencing pain after operation Age. Age did not seem to be an important factor in influencing vital capacity impairment, although in one TABLE II. Neuroticism and chest complications trial (trial 3) vital capacity impairment appeared to be less in the older patients. This might have been lor 2 0 3, 4 or 5 related to the tendency of the neuroticism score of the chest chest chest patients to decrease with age. The lie score, on the complica- complica- complication tions tions other hand, increased with age. n (%) (%) (%) Social class. Social class was not measured in the female patients. In the male patients, the details for Low group 41 27 14 59 social class are provided in table III, with the results (N«5) 43 28 29 Medium group 72 of t tests for differences in vital capacity impairment 37 27 19 54 High group between each of the social class groups. It was found (N> 12) that patients in social class 4 had a significantly higher vital capacity impairment compared with those n = number of patients. patients in any other group. While those patients in of the patients with a neuroticism score less than 5 social class 3 had a significantly greater impairment had no complications while 14% had a chest complica- than those in social class 2, there were no other tion score of 3,4 or 5. In the case of the patients with significant differences. a high N score (N ^ 12) the proportions were reversed. Smoking habits. There was no correlation between The table suggests that patients with N score less a patient's smoking habits and the changes after than 5 were less likely to have complications, while operation. There was a correlation between smoking those with a high score of over 12 were particularly habits and neuroticism score: those patients who likely to have several complications following surgery. smoked more had a lower neuroticism score than Extroversion. The results did not indicate any light or non-smokers. Previous workers have found a interrelationship between extroversion scores and correlation between a low neuroticism score and lung neuroticism, vital capacity impairment or subjective cancer in male patients (Kissen and Eysenck, 1962).
Downloaded from http://bja.oxfordjournals.org/ at University of California, Santa Barbara on July 2, 2015
40-
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BRITISH JOURNAL OF ANAESTHESIA
262 TABLE III. Vital Capacity impairment (VC imp.) of patients according to social class Mean 0/
la
VCimp. Social Social Social Social Social
class class class class class
1 2 3 4 5
0 10 55 41 34
60.9 67.2 71.8 63.2
SD
13.63 9.41 10.45 12.99
Mean* N score
SD
6.50 7.00 8.64 7.75
6.23 3.71 4.02 3.86
an increase of the mean vital capacity impairment from 55 to 80% over the range of the subjective pain assessment readings. In three of the trials the patients' vital capacity impairment was measured on the 6th day after operation also and the interrelationship between the 1st day and 6th day impairment of capacity is seen in figure 3. The vertical distance of the point from the x
=y
Social class 2 Social class 3 Social class 4 Social class 3 Social class 4 Social class 5
0.1
* There were no significant differences between the mean neuroticism scores for each of the social class groups. n = number of patients.
Interrelationship of postoperative details
There was an overall correlation between the patients' vital capacity impairment and the patients' subjective pain as assessed by the visual analogue scale (table I). Figure 2 illustrates the mean impairment for each pain score in these studies and indicates
60
80
100
Day 1
FIG. 3. Changes in vital capacity impairment from day 1 to day 6. The vertical distance of the readings from the line x = y measures changes in vital capacity impairment between 1st and 6th day after operation.
% V. C. IMPAIRMENT ( 2 4 HOURS )
100 T
80-
60-
40-
20-
I
10 Subjective Pain Assessment (0 - - • 10 ) FIG. 2. Mean impairment of vital capacity for each pain score.
x = y line (45° line) shows the change in vital capacity impairment between the two times. Although all patients except two showed a lessening of the vital capacity impairment over this period, there was a marked variation in the rate of improvement of the individual patients. An interrelationship was found between the 24 h vital capacity impairment and the chest complication scores (table IV). An analysis similar to that for neuroticism and chest complications was made, the patients being arranged in increasing order of vital capacity impairment and divided into four equal groups. The two middle quarters were again found to provide similar results in terms of chest complications, and were joined. The majority of the group of patients with the lowest vital capacity impairment (less than 58%) had no chest complications, and only 18% had complications scores of 3 or more. In the case of the patients with marked impairments of vital
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Results of t tests for differences in mean % VC imp.
263
PERSONALITY AND POSTOPERATIVE FACTORS TABLE IV. Vital Capacity impairment and chest complications 3, 4 or 5 0 lor 2 chest chest chest complica- complica- complications tion tions (%)
(%)
(%)
Low group 38 (imp. s= 58) Medium group 72 40 High group (imp. > 74)
66
16
18
42 17
28 37
30 46
n = number of patients. ACKNOWLEDGEMENTS
capacity (more than 74%) the incidence of complications was reversed as only 17% had no complications and 46% had scores of 3 or more. Statistical comparison was made of the vital capacity impairments of patients with the various complication scores and the impairment of the group of patients with no complications (score 0) was in every case significantly less (P<0.05) than that of patients with complications (scores 1, 2, 3 or 4). The results complete the link between neurotirism, vital capacity impairment and chest complications and indicate that these three factors are closely interrelated. DISCUSSION
The analysis of the greater number of data available in these four trials has provided a better indication of the interrelationship between neuroticism and postoperative factors than was possible with the individual trials. The results indicate that a marked impairment of vital capacity after operation can be expected in a patient with a high neuroticism score. In this way, by a test before operation, it is possible to predict a certain "problem group" of patients. These patients will warrant special attention, perhaps by more intense reassurance before operation (Egbert et al., 1964), by extradural block (Simpson et al., 1961) or by inhalation analgesia (Parbrook and Kennedy, 1964). It cannot be assumed that a patient with a low neuroticism score will have a smooth course after surgery, as there is a wide variation of the vital capacity impairment in these patients; consequently it is reasonable to suggest that neuroticism is only one of several factors which adversely affect the prognosis of a patient after surgery. Although the study only reveals associations and cannot provide the reason underlying the effects of the N scores, the interrelationship between N score,
Professor M. R. Bond is thanked for advice on psychological aspects of these studies and Mr A. D. McLaren for statistical supervision. Mr P. Boyle is currently supported by a grant from the Scottish Home and Health Department and the studies reported were supported by a grant from the Medical Research Council. REFERENCES
Dalrymple, D. G., and Parbrook, G. D. (1976). Personality assessment and postoperative analgesia. A study in male patients undergoing elective gastric surgery. Br. J. Anaesth., 48,593. Steel, D. F. (1973). Factors predisposing to postoperative pain and pulmonary complications. A study of female patients undergoing elective cholecystectomy. Br. J. Anaesth., 45,589. Egbert, L. D., Battit, G. E., Welch, C. E., and Bartlett, M. K. (1964). Reduction of postoperative pain by encouragement and instruction of patients. N. Engl. J. Med., 270,825. Eysenck, S. G. B., and Eysenck, H. J. (1969). Scores on three personality variables as a function of age, sex and social class. Br.J. Soc. Clin. Psychol, 8,69. Henderson, J. J., and Parbrook, G. D. (1976). Influence of anaesthetic technique on postoperative pain. A comparison of anaesthetic supplementation with halothane and with phenoperidine. Br.J. Anaesth., 48,587. Kissen, D. M., and Eysenck, H. J. (1962). Personality in male lung cancer patients. J. Psychosom. Res., 6,123. Knowles, J. B., and Kreitman, N. (1965). The Eysenck Personality Inventory—some considerations. Br. J. Psychiatr., 111,755. McColl, I., Drinkwater, J. E., Hulme-Moir, I., and Donnan, S. P. B. (1971). Prediction of success or failure of gastric surgery. Br.J. Surg., 58,768. Parbrook, G. D., and Kennedy, B. R. (1964). Value of premixed nitrous oxide and oxygen mixtures in the relief of postoperative pain. Br. Med.J., 2,1303. Steel, D. F., and Dalrymple, D. G. (1973). Factors predisposing to postoperative pain and pulmonary complications. A study of male patients undergoing elective gastric surgery. Br.J. Anaesth., 45,21. Simpson, B. R. J., Parkhouse, J., Marshall, R., and Lambrechts, W. (1961). Extradural analgesia and the prevention of postoperative pulmonary complications. Br. J. Anaesth., 33,628.
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n
pain, vital capacity impairment and chest complications suggests that a patient with a high neuroticism score will suffer more abdominal pain, that this leads to a splinting effect on the diaphragm and that a higher risk of chest complications will follow in consequence. In addition to the relationship of neuroticism to pain, other workers have shown that this factor is also related to the long-term prognosis after ulcer surgery (McColl et al., 1971). A routine personality check by means of an inventory will be of value in all patients scheduled for upper abdominal operations.
BRITISH JOURNAL OF ANAESTHESIA
264 INTER-RELATION DE LA PERSONNALITE ET DBS FACTEURS POST-OPERATOIRES RESUME
DIE WECHSELWIRKUNG VON PERSONLICHKEIT UND POSTOPERTIVEN FAKTOREN ZUSAMMENFASSUNG
Eine zusammengesetzte statistische Analyse der Resultate von vier Versuchen mit Patienten nach chirurgischen Eingriffen im oberen Abdomen wurde durchgefuhrt. Es ergab sich eine deutliche Wechselwirkung zwischen den vor der Operation durch Personlichkeitstests gemessenen neurotischen Werten und dem nach der Operation festgestellten Prozentsatz der Beeintrachtigung lebenswichtiger
LA INTERRELACION DE LOS FACTORES DE PERSONALIDAD Y DEL POSTOPERATORIO SUMARIO
Se efectu6 un analisis compuesto estadistico de los resultados de cuatro pruebas comprendiendo pacientes sometidos a operaciones del abdomen alto. Se revelo una marcada correlation entre la valoracion de neuroticismo medida segun un inventario de la personalidad antes de la operation y el porcentaje de disminuci6n de la capacidad vital que se hallo tras la operation. El neuroticismo tambien se correspondio con el dolor, medido mediante una escala analoga visual. Los valores para disminuci6n de capacidad vital y dolor sujetivos se hallaban interrelacionados y tan to el neurotitismo y la disminucion de capacidad vital estaban relacionados con el indice de complicationes toracicas. La evaluation de la personalidad preoperatoriamente puede identificar a un grupo de pacientes que padeceren marcado dolor y limitation de capacidad vital en el postoperatorio.
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On a fait une analyse statistique composee des resultats de quatre essais comprenant des malades subissant une intervention chirurgicale a la partie superieure de l'abdomen. Elle a revels une correlation marquee entre le score de nevrose, tel qu'on peut le mesurer par un inventaire de la personnalite avant l'operation et le pourcentage d'alte>ation de la capacite vitale existant apres l'operation. La neVrose 6tait egalement en correlation avec la douleur, tel qu'on peut la mesurer par une ichelle analogue visuelle. Les lectures de l'alt&ration de la capacite vitale et de la douleur subjective etaient inter-reliees et la nevrose et l'alteiation de la capacite vitale etaient reliees au taux de complication de la poitrine. L'evaluation de la personnalit6 avant Top^ration permet d'identifier le groupe de malades qui souffrira de douleurs prononcees et qui aura une restriction de la capacity vitale apres I'op6ration.
Funktionen. Diese neurotischen Werte zeigten auch eine Wechselbeziehung zu dem nach einer visuellen Analogskala gemessenen Schmerz. Die Beeintrachtigung lebenswichtiger Funktionen und die Messungen der subjektiven Schmerzen waren aufeinander bezogen, und sowohl diese Beeintrachtigung als auch die neurotischen Werte hatten einen Zusammenhang mit der Haufigkeit von BrustraumKomplikationen. Durch die Personlichkeitsbewertung vor der Operation kann eine Gruppen von Patienten bestimmt werden, bei der es nach der Operation zu starkeren Schmerzen und zu einer Beeintrachtigung lebenswichtiger Funktionen kommen wird.