British Journolof lJrology(1992).69,144-1415
01992 British Journal of Urology
Pyuria: Index of Infection in Patients with Spinal Cord Injuries* E. B. MENON and E. S. TAN Department of Rehabilitation Medicine, Tan Tock Seng Hospital, Singapore
Summary-Little is known about the significance of pyuria in patients with spinal cord injuries. The progress in hospital of 55 such patients was studied. They were divided into 2 groups according to the method of bladder drainage on admission. Group A comprised 43 patients with indwelling catheters. Group B comprised 12 patients who were able to void with tapping, with/without compression and on intermittent catheterisation. The results showed that group A had a mean pyuria level of 185 WBC/HPF on admission. The incidence of urinary tract infection was 4 per patient during hospitalisation and the mean duration of bladder training was 8 2 days. Group B had a mean pyuria level of 3 2 WBC/HPF on admission. The incidence of urinary tract infection was 1 per patient during hospitalisation and the mean duration of bladder training was 40 days. The difference between groups A and B for all 3 parameters was statistically significant. These results suggest that patients with spinal cord injuries and indwelling catheters have a higher pyuria level and an increased risk of significant morbidity secondary to urinary tract infection, 0 was especially at the pyuria level of 100 WBC/HPF. A low pyuria level of ~ 3 WBC/HPF associated with a nil or low incidence of bacteriuria and urinary tract infection in our patients.
Loss of normal bladder function results in an increased risk of developing urinary tract infection. Recurrent pyuria and bacteriuria continue to be a problem in most patients with spinal cord injuries. Indwelling urethral catheterisation is the most frequent form of bladder drainage used in patients with neurogenic bladder dysfunction secondary to spinal cord injury (SCI), acute systemic illnesses, strokes, neurological and rheumatological diseases and head injury patients, especially in the acute phase. Indwelling urethral catheters contribute to the development of significant bacteriuria and are responsible for the high incidence of urological complications that include lower and upper urinary tract infections, vesicoureteric reflux, urinary tract
stones, periurethral inflammation, abscesses and possible septicaemia (Kyle, 1968; Warren et al., 1981). Pyuria is often found in association with urinary tract infection (UTI) and quantitative estimates are often used by clinicians to help in the diagnostic evaluation of urinary tract infection and the significance of bacteriuria in asymptomatic patients. Stamm (1983) suggested that in the absence of symptoms, pyuria was one means of distinguishing urinary tract invasion from bacterial colonisation of the bladder. Anderson and Hsieh-Ma (1983), noting that many spinal cord injury patients with pyuria were asymptomatic, stated that the level of pyuria should be evaluated to determine the degree of urinary tract invasion. Since pyuria is one index of urinary tissue * Presented at Eleventh Scientific Meeting, Chapter of Physicians, Academy of Medicine, Singapore, on 26 inflammation, we postulated that SCI patients with January 1991 and First Regional Conference on Spinal indwelling catheters and high levels of pyuria were Cord Injury in Bhubaneswar, India, on 1 February 1991. more likely to develop recurrent urinary tract Accepted for publication 24 September 1991 infection, fever and other urological complications.
145
PYURIA IN PATIENTS WITH SPINAL CORD INJURIES
The progress in hospital of 55 SCI patients was therefore studied to determine whether such a relationship existed.
tion. Student’s t test was used to determine the significance of the differences between Groups A and B in relation to pyuria on admission, the incidence of urinary tract infection and the duration of bladder training.
Patients and Methods We studied the progress in hospital of all SCI patients admitted to this department between August 1989 and August 1990. The patients were divided into 2 groups, based on the method of bladder drainage upon admission. Patients were excluded from the study if: (1) Urine cultures grew < 100,000 colony forming units/ml. (2) > 100,000 Cundidu species were present in the urine culture. (3) They were on antibiotics at the time of admission. (4) They were febrile on admission. ( 5 ) Nephrolithiasis was present. (6) Genital infections, including vaginitis, were present. (7) Grades I11 or IV pressure sores were present. (8) Systemic infection was present. Urine analysis and culture were done twice a week in order to determine the level of pyuria on admission and during their stay in hospital, and the incidence of pyuria and bacteriuria was then correlated.
Results None of the patients developed any other significant systemic infection during the study. All responded to a combination of oral or intravenous antibiotics and regular bladder washouts. Only 2 patients went home or to institutional care with indwelling catheters. Of the remaining 53 patients, 45 could void with/without tapping and compression after a period of bladder training; 8 patients could not be bladder trained and went home on a regime of clean intermittent self-catheterisation. Statistical analysis of the data showed that: (1) The difference in the pyuria level on admission for Group A and Group B was statistically significant (t = 2.078, P < 0.05). (2) The difference in the incidence of urinary tract infection for Group A and Group B was significant (t = 2.047, P < 0.05). (3) The difference in the duration of bladder training between Group A and Group B was significant (t = 2.175, P < 0.05).
Discussion Statistical Analysis Data were obtained from case records and urology charts and the age, sex, level of spinal injury, level of pyuria on admission, pyuria during episodes of urinary tract infection and relevant bacterial urinary cultures were included (Table). These observations were carried out while patients were on indwelling catheters or on intermittent cathetisa-
Most clinicians agree that asymptomatic bacteriuria should not be treated in chronically catheterised patients because routine treatment encourages the emergence of resistant organisms (Merritt, 1976; Kunin, 1987). The classical symptoms of urinary tract infection (dysuria, frequency, urgency and suprapubic pain) are unreliable and usually absent in SCI patients
Table Details of Patients Method of bladder drainage Indwelling catheter (Group A ) No. of patients 43 Mean age (years) 35 185 Mean pyuria rate on admission (WBC/HPF) Mean pyuria rate during febrile state or on starting antibiotics 155 (WBC/HPF) Mean incidence of UTI/patient/hospitalisation 4 Mean duration of bladder training (days) 82 114 Mean duration of stay in Rehabilitation Department (days)
Intermittent cutheterisution (Group B )
12 43 32 115 1 40 60
146 with neurogenic bladders and impaired sensation. Most lower urinary tract infections are asymptomatic in this population (Merritt, 1976). Clinicians usually wait until objective criteria such as fever are present to determine which patients should receive antibiotic therapy. However, by the time fever is present in SCI patients, the upper urinary tract may be involved. Pyuria is an index of tissue inflammation. Its absence indicates that no urinary tract infection is present; its presence helps to distinguish between colonisation and true infection of the urinary tract (Stamm, 1983; Hooton et al., 1984). However, the measurement of pyuria by microscopic examination is poorly reproducible because of observer bias, technician error, lack of standardisation of the thickness of the film and varying volumes of resuspension (Gadeholt, 1964; Gribble et al., 1988). This study supports the claim that spinal cord injury patients with indwelling catheters have a higher pyuria level than those without. This predisposes them to an increased incidence of urinary tract infections, leading to significant morbidity. Patients with a pyuria level > 100 WBC/ HPF developed a urinary tract infection, had associated bacteriuria and required antibiotic treatment. There was also a higher incidence of urinary tract infection in this group of patients. A low pyuria level of 30 WBC/HPF was generally found in SCI patients without indwelling catheters and they showed a significantly lower incidence of urinary tract infection. It is also important to note that the duration of bladder training was significantly shorter in Group B patients, who had a low pyuria level ( 100 WBC/HPF). We conclude that if clinicians wish to reduce the risk of urinary infection in patients with neurogenic bladder, indwelling catheters must be removed as soon as possible. The pyuria level should be monitored because a low pyuria level ( 100 WBC/HPF) in this study was always associated with bacteriuria and systemic symptoms and required oral or intravenous antibiotics.
BRITISH JOURNAL OF UROLOGY
The use of pyuria as an index of infection has helped us to treat urinary tract infection in SCI patients, who do not usually have classical symptoms of infection. If urinary tract infection is treated early and adequately, morbidity can be reduced, as can the incidence of urological complications. This enables patients to go home sooner and helps them to live a more meaningful life with better and longer preservation of renal function, the ultimate goal of any method of neurogenic bladder management.
Acknowledgements We are indebted to our dedicated team of nursing staff and medical officers, who have painstakingly documented all of our patients’ investigations. We are also grateful to our typist, Zaiton, for her zeal, patience and dedication in typing the manuscript.
References Anderson, R. U. and Hsieh-ma, S. T. (1983). Association of bacteriuria and pyuria during intermittent catheterization after spinal cord injury. J. Uro/.,130,299-301. Gadeholt, H. (1964). Quantitative estimation of urinary tract sediment, with special reference to sources of error. Er. Med. J., 1, 1547-1549. Gribble, M. J., McCaUum, N. M. and Schecter, M. T. (1988). Evaluation of diagnostic criteria for bacteriuria in acutely spinal cord injured patients undergoing intermittent catheterization. Diagn. Microbiol. Infecf. Dis., 9, 197-206. Hooton, T. M., O’Shaughnessy, E. J., Clowers, D. et d (1984). Localization of urinary tract infection in patients with spinal cord injury. J. Infect. Dis., 150, 85-91. Kunin, C. M. (1987). Care of urinary catheter. In Defection, Prevention and Management of Urinary Tract Infections, ed. Kunin, C. M. Fourth edition. Pp. 245-297. Philadelphia: Lea and Febiger. Kyle, E. W. (1968). Complications of indwelling catheters. Paraplegia, 6 , 1-4. Merritt, J. L. (1976). Urinary tract infections, causes and management, with particular reference to patients with spinal cord injury: review. Arch. Phys. Med. Rehabil., 51,365-373. Stamm, W. E. (1983). Measurement of pyuria and its relation to bacteriuria. Am. J. Med., 75, 53-58. Warren, J. W., Muncie, H. L., Bergquist, E. J. et d (1981). Sequelae and management of urinary infection in patients requiring chronic catheterization. J. Urol., 125, 1-8.
The Authors E. B. Menon, MRCP, Registrar. E. S. Tan, FACRM, Head of Department of Rehabilitation Medicine. Requests for reprints to: E. B. Menon, St Stephen’s Hospital, Tis-Hazari, Delhi-110054, India.
01992 British Journal of Urology
Pyuria: Index of Infection in Patients with Spinal Cord Injuries* E. B. MENON and E. S. TAN Department of Rehabilitation Medicine, Tan Tock Seng Hospital, Singapore
Summary-Little is known about the significance of pyuria in patients with spinal cord injuries. The progress in hospital of 55 such patients was studied. They were divided into 2 groups according to the method of bladder drainage on admission. Group A comprised 43 patients with indwelling catheters. Group B comprised 12 patients who were able to void with tapping, with/without compression and on intermittent catheterisation. The results showed that group A had a mean pyuria level of 185 WBC/HPF on admission. The incidence of urinary tract infection was 4 per patient during hospitalisation and the mean duration of bladder training was 8 2 days. Group B had a mean pyuria level of 3 2 WBC/HPF on admission. The incidence of urinary tract infection was 1 per patient during hospitalisation and the mean duration of bladder training was 40 days. The difference between groups A and B for all 3 parameters was statistically significant. These results suggest that patients with spinal cord injuries and indwelling catheters have a higher pyuria level and an increased risk of significant morbidity secondary to urinary tract infection, 0 was especially at the pyuria level of 100 WBC/HPF. A low pyuria level of ~ 3 WBC/HPF associated with a nil or low incidence of bacteriuria and urinary tract infection in our patients.
Loss of normal bladder function results in an increased risk of developing urinary tract infection. Recurrent pyuria and bacteriuria continue to be a problem in most patients with spinal cord injuries. Indwelling urethral catheterisation is the most frequent form of bladder drainage used in patients with neurogenic bladder dysfunction secondary to spinal cord injury (SCI), acute systemic illnesses, strokes, neurological and rheumatological diseases and head injury patients, especially in the acute phase. Indwelling urethral catheters contribute to the development of significant bacteriuria and are responsible for the high incidence of urological complications that include lower and upper urinary tract infections, vesicoureteric reflux, urinary tract
stones, periurethral inflammation, abscesses and possible septicaemia (Kyle, 1968; Warren et al., 1981). Pyuria is often found in association with urinary tract infection (UTI) and quantitative estimates are often used by clinicians to help in the diagnostic evaluation of urinary tract infection and the significance of bacteriuria in asymptomatic patients. Stamm (1983) suggested that in the absence of symptoms, pyuria was one means of distinguishing urinary tract invasion from bacterial colonisation of the bladder. Anderson and Hsieh-Ma (1983), noting that many spinal cord injury patients with pyuria were asymptomatic, stated that the level of pyuria should be evaluated to determine the degree of urinary tract invasion. Since pyuria is one index of urinary tissue * Presented at Eleventh Scientific Meeting, Chapter of Physicians, Academy of Medicine, Singapore, on 26 inflammation, we postulated that SCI patients with January 1991 and First Regional Conference on Spinal indwelling catheters and high levels of pyuria were Cord Injury in Bhubaneswar, India, on 1 February 1991. more likely to develop recurrent urinary tract Accepted for publication 24 September 1991 infection, fever and other urological complications.
145
PYURIA IN PATIENTS WITH SPINAL CORD INJURIES
The progress in hospital of 55 SCI patients was therefore studied to determine whether such a relationship existed.
tion. Student’s t test was used to determine the significance of the differences between Groups A and B in relation to pyuria on admission, the incidence of urinary tract infection and the duration of bladder training.
Patients and Methods We studied the progress in hospital of all SCI patients admitted to this department between August 1989 and August 1990. The patients were divided into 2 groups, based on the method of bladder drainage upon admission. Patients were excluded from the study if: (1) Urine cultures grew < 100,000 colony forming units/ml. (2) > 100,000 Cundidu species were present in the urine culture. (3) They were on antibiotics at the time of admission. (4) They were febrile on admission. ( 5 ) Nephrolithiasis was present. (6) Genital infections, including vaginitis, were present. (7) Grades I11 or IV pressure sores were present. (8) Systemic infection was present. Urine analysis and culture were done twice a week in order to determine the level of pyuria on admission and during their stay in hospital, and the incidence of pyuria and bacteriuria was then correlated.
Results None of the patients developed any other significant systemic infection during the study. All responded to a combination of oral or intravenous antibiotics and regular bladder washouts. Only 2 patients went home or to institutional care with indwelling catheters. Of the remaining 53 patients, 45 could void with/without tapping and compression after a period of bladder training; 8 patients could not be bladder trained and went home on a regime of clean intermittent self-catheterisation. Statistical analysis of the data showed that: (1) The difference in the pyuria level on admission for Group A and Group B was statistically significant (t = 2.078, P < 0.05). (2) The difference in the incidence of urinary tract infection for Group A and Group B was significant (t = 2.047, P < 0.05). (3) The difference in the duration of bladder training between Group A and Group B was significant (t = 2.175, P < 0.05).
Discussion Statistical Analysis Data were obtained from case records and urology charts and the age, sex, level of spinal injury, level of pyuria on admission, pyuria during episodes of urinary tract infection and relevant bacterial urinary cultures were included (Table). These observations were carried out while patients were on indwelling catheters or on intermittent cathetisa-
Most clinicians agree that asymptomatic bacteriuria should not be treated in chronically catheterised patients because routine treatment encourages the emergence of resistant organisms (Merritt, 1976; Kunin, 1987). The classical symptoms of urinary tract infection (dysuria, frequency, urgency and suprapubic pain) are unreliable and usually absent in SCI patients
Table Details of Patients Method of bladder drainage Indwelling catheter (Group A ) No. of patients 43 Mean age (years) 35 185 Mean pyuria rate on admission (WBC/HPF) Mean pyuria rate during febrile state or on starting antibiotics 155 (WBC/HPF) Mean incidence of UTI/patient/hospitalisation 4 Mean duration of bladder training (days) 82 114 Mean duration of stay in Rehabilitation Department (days)
Intermittent cutheterisution (Group B )
12 43 32 115 1 40 60
146 with neurogenic bladders and impaired sensation. Most lower urinary tract infections are asymptomatic in this population (Merritt, 1976). Clinicians usually wait until objective criteria such as fever are present to determine which patients should receive antibiotic therapy. However, by the time fever is present in SCI patients, the upper urinary tract may be involved. Pyuria is an index of tissue inflammation. Its absence indicates that no urinary tract infection is present; its presence helps to distinguish between colonisation and true infection of the urinary tract (Stamm, 1983; Hooton et al., 1984). However, the measurement of pyuria by microscopic examination is poorly reproducible because of observer bias, technician error, lack of standardisation of the thickness of the film and varying volumes of resuspension (Gadeholt, 1964; Gribble et al., 1988). This study supports the claim that spinal cord injury patients with indwelling catheters have a higher pyuria level than those without. This predisposes them to an increased incidence of urinary tract infections, leading to significant morbidity. Patients with a pyuria level > 100 WBC/ HPF developed a urinary tract infection, had associated bacteriuria and required antibiotic treatment. There was also a higher incidence of urinary tract infection in this group of patients. A low pyuria level of 30 WBC/HPF was generally found in SCI patients without indwelling catheters and they showed a significantly lower incidence of urinary tract infection. It is also important to note that the duration of bladder training was significantly shorter in Group B patients, who had a low pyuria level ( 100 WBC/HPF). We conclude that if clinicians wish to reduce the risk of urinary infection in patients with neurogenic bladder, indwelling catheters must be removed as soon as possible. The pyuria level should be monitored because a low pyuria level ( 100 WBC/HPF) in this study was always associated with bacteriuria and systemic symptoms and required oral or intravenous antibiotics.
BRITISH JOURNAL OF UROLOGY
The use of pyuria as an index of infection has helped us to treat urinary tract infection in SCI patients, who do not usually have classical symptoms of infection. If urinary tract infection is treated early and adequately, morbidity can be reduced, as can the incidence of urological complications. This enables patients to go home sooner and helps them to live a more meaningful life with better and longer preservation of renal function, the ultimate goal of any method of neurogenic bladder management.
Acknowledgements We are indebted to our dedicated team of nursing staff and medical officers, who have painstakingly documented all of our patients’ investigations. We are also grateful to our typist, Zaiton, for her zeal, patience and dedication in typing the manuscript.
References Anderson, R. U. and Hsieh-ma, S. T. (1983). Association of bacteriuria and pyuria during intermittent catheterization after spinal cord injury. J. Uro/.,130,299-301. Gadeholt, H. (1964). Quantitative estimation of urinary tract sediment, with special reference to sources of error. Er. Med. J., 1, 1547-1549. Gribble, M. J., McCaUum, N. M. and Schecter, M. T. (1988). Evaluation of diagnostic criteria for bacteriuria in acutely spinal cord injured patients undergoing intermittent catheterization. Diagn. Microbiol. Infecf. Dis., 9, 197-206. Hooton, T. M., O’Shaughnessy, E. J., Clowers, D. et d (1984). Localization of urinary tract infection in patients with spinal cord injury. J. Infect. Dis., 150, 85-91. Kunin, C. M. (1987). Care of urinary catheter. In Defection, Prevention and Management of Urinary Tract Infections, ed. Kunin, C. M. Fourth edition. Pp. 245-297. Philadelphia: Lea and Febiger. Kyle, E. W. (1968). Complications of indwelling catheters. Paraplegia, 6 , 1-4. Merritt, J. L. (1976). Urinary tract infections, causes and management, with particular reference to patients with spinal cord injury: review. Arch. Phys. Med. Rehabil., 51,365-373. Stamm, W. E. (1983). Measurement of pyuria and its relation to bacteriuria. Am. J. Med., 75, 53-58. Warren, J. W., Muncie, H. L., Bergquist, E. J. et d (1981). Sequelae and management of urinary infection in patients requiring chronic catheterization. J. Urol., 125, 1-8.
The Authors E. B. Menon, MRCP, Registrar. E. S. Tan, FACRM, Head of Department of Rehabilitation Medicine. Requests for reprints to: E. B. Menon, St Stephen’s Hospital, Tis-Hazari, Delhi-110054, India.
