**2.1. Urinary tract infection**

Urinary tract infections (UTI) still cause significant morbidity in patients with spinal cord injury, although mortality due to urinary tract complications has decreased dramatically [9]. Patients with spinal cord injuries (SCIs) and complete or incomplete paraplegia are prone to frequent, recurrent, or chronic UTI. The reason for the increased risk of acquiring UTI is multifactorial, including reduced sensation of classical UTI symptoms, incomplete bladder emptying, frequent catheterizations, or chronic urinary tract catheters [10]. The rate of UTI in an SCI patient is 2.5 episodes in patient per year. UTI is the second leading cause of mortality in SCI patients [11]. Patients with SCI who have urinary catheters have an increased risk of UTI. Urinary tract infection can be important and can cause serious complications including sepsis and septic shock if it is not diagnosed and treated.

complications such as prolonged hospital stay and increased cost of management of patients. Several organs may be affected and problems in these organs can be even more important than the primary event. The types of infections in these patients are different and related to several factors. Inabilities to changing position or ineffective cough, using several necessary devices, prolonged hospitalization, and several other factors, in patients with SCI, predispose them to different types of infections. Inability to walk, sit, or change position may lead to pressure ulcers, skin and soft tissue infection, and osteomyelitis. Reduced tissue perfusion increases the spinal cord-injured patient's susceptibility to pressure ulcers [1] during the acute and rehabilitation phases, most frequently over bony prominences such as the sacrum, tuber ischii, heel, malleolus, and trochanter [2]. Physical and psychosocial elements such as nutrition, past history of pressure ulcers, and social supports can be important in developing ulcers [3]. Ineffective cough and retained pulmonary secretion may lead to pneumonia. Most of the patients need intubation in the course of hospitalization that predisposes them to ventilator-associated pneumonia. Ventilator-associated pneumonia is the most frequent nosocomial infection in patients receiving mechanical ventilation and contributes to a longer intensive care unit stay and high morbidity and mortality [4, 5]. Use of high doses of corticosteroid for management of some patients with SCI can increase the risk of infection. In those patients who need surgical intervention, the operation time is usually prolonged. Sometimes, the use of an external device is mandatory for fixation of unstable vertebral column. The SCI patients may develop bloodstream infection during the hospital admission. During bloodstream infection occurrence in an SCI population, multidrug-resistant organisms are frequent [6]. ICU-acquired bloodstream infection in the intensive care unit is still associated with a high mortality rate. The increase of antimicrobial drug resistance makes its treatment increasingly challenging. ICU bloodstream infection is associated with a 40% increase in the risk of 30-day mortality, particularly if the early antimicrobial therapy is not adequate [7]. Paying attention to antibiotic therapy is important in SCI patients. Antibiotic resistance is of great concern for both infection control and the treatment of infectious diseases. Drug-resistant pathogens, such as methicillin-resistant *Staphylococcus aureus* (MRSA), *Pseudomonas aeruginosa*, *Acinetobacter* and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, are associated with inappropriate antibiotic treatment that resulted in adverse outcomes. In addition, unnecessary use of broad-spectrum

antibiotics for patients with non-drug-resistant pathogens increases mortality [8].

**2. Infectious diseases after spinal cord injury**

**2.1. Urinary tract infection**

92 Essentials of Spinal Cord Injury Medicine

These can be the risk factors for developing infections in SCI patients. In this chapter, the cause of infections, predisposing factors, diagnosis, management, and prevention will be discussed.

Urinary tract infections (UTI) still cause significant morbidity in patients with spinal cord injury, although mortality due to urinary tract complications has decreased dramatically [9]. Patients with spinal cord injuries (SCIs) and complete or incomplete paraplegia are prone to frequent, recurrent, or chronic UTI. The reason for the increased risk of acquiring UTI is Using Foley catheter is usually accompanied with colonization of microorganisms and infection [12]. Bacterial biofilm formation of Foley catheter can cause cystitis [10]. About 80% of UTIs follow urinary catheter insertion. Nitrofurazone-coated and silver alloycoated catheters can decrease asymptomatic bacteriuria during short-term (<30 days) use in comparison with latex or silicon catheters. The risk of infection is higher with long-term catheterization, and it is safe to remove it early after surgery. Latex and silicone catheters have the same infection rates, but Foley catheters cause more symptomatic bacteriuria and UTI than intermittent catheterizations. Changing the drainage bags and adding antiseptic solution to bags cannot prevent UTI in patients [13]. There are several risk factors for UTI in SCI patients. Reflux of vesicoureteral, postvoiding residuals, outlet obstruction, urinary tract stones, and bladder overdistension [14]. These patients are exposed to antibiotics because of frequent infections that may be an important risk factor for resistant microorganism infection [15]. Today, UTI may be difficult to treat in SCI patients because of antibiotic-resistant organisms. The SCI patients are also colonized by resistant organisms because of recurrent and prolonged hospitalization [16]. The main causative agent of UTI in SCI population is usually derived from the patient's flora. The indwelling catheter has a great role in infection and the duration of catheterization is the most important risk factor. If the patient carries a catheter more than 30 days, the risk of infection with multiple organisms will increase. Although short-term catheterization can be risk factor for bacteriuria, it is usually asymptomatic and often by a single microorganism [17]. It is better to use hydrophilic-coated catheter for intermittent catheterization in SCI patients during acute inpatient rehabilitation. These kinds of catheters can postpone the development of UTI. They also reduce the incidence of bacteriuria and infection. Reduction of complications and treatment costs and preventing the emergence of antibiotic-resistant organisms are other benefits of hydrophilic-coated catheters [18]. Substitution of indwelling catheter with intermittent catheterization during the rehabilitation phase will reduce development of UTI [9]. The unitary catheter should work in a closed system so that no organism can enter the system. It is also important to reduce the duration of catheterization. Sometimes intermittent catheterization, condom sheet catheter, and suprapubic catheters may substitute indwelling catheterization to reduce the risk of infection [17]. Intermittent catheterization is safe and is advised to prevent UTI in SCI patients. Condom sheet catheter can be used in patients who are able to urinate and there is no pathology or injury in urethra. In some patients, where using condom sheet catheter or intermittent catheterization is not suitable or possible, the physician may decide to use suprapubic catheter. The physicians should be aware of these two points that SCI patients may not have the classic symptoms of UTI and urinary infection may cause urologic complications [15].

#### *2.1.1. Diagnosis*

Diagnosis of UTI is usually based on the results of urine culture, although in some condition like low titer of organism in urine, slow-growing pathogens and unusual organisms, results of culture may be unreliable [12]. The physician should be aware of how to diagnose UTI and distinguish it from colonization. These patients are at increased risk of acquiring multidrug-resistant bacteria because they are admitted due to UTI or other infectious diseases and take antibiotics. Several resistant organisms may cause UTI in SCI patients including multidrug-resistant *Pseudomonas aeruginosa*, ESBL (extended-spectrum β-lactamase-producing) *Escherichia coli*, resistant *Klebsiella* spp. and MRSA (methicillin-resistant *Staphylococcus aureus*) [10]. Due to multiple risk factors for acquisition of infection, especially with resistant organisms, complicated UTI may develop with unusual and resistant bacteria. The infection may be polymicrobial. Proteus, Providencia, Serratia, and enterococci may also cause UTI in these groups [9]. For the diagnosis of UTI, culture is needed to find to causative agent, but if the patient is not symptomatic, it is not necessary to get culture, because the patients usually do not need treatment [17]. When UTI is diagnosed in SCI patient, the physician should evaluate the patient for anatomical and functional disorders. It is important to correct any correctable disorder for optimal treatment success [9].

*2.1.3. Prevention and prophylaxis*

bladders [21].

**2.2. Skin and soft tissue infection**

Prevention of UTI in SCI patients plays an important role in hospital and even in rehabilitation courses of these patients. Paying attention to urinary tract hygiene is necessary. Some patients may encounter relapse or reinfection. In these patients, evaluation of structural and functional disorders should be performed. Duration of previous treatment and probable complications like urine residue and urinary stone should be assessed. Antibiotics may be used as prophylaxis, but it is important to notice that it can be used when recurrent UTI occurs and when all structural and functional abnormalities are corrected. Prophylaxis is not recommended for patients carrying indwelling catheters, and for those who have intermittent catheterization, it is contraventional [9]. Physicians can most effectively prevent UTI by avoiding use of longterm catheters, short duration of catheter use, and substituting intermittent catheterization with indwelling catheter. Daily washing of the catheter or perianal or periurethral areas has no preventive effect. It is recommended to use antibiotic immediately before any invasive procedure on urinary tract system [19]. Probiotics may be useful as prophylactic agents. They may decrease the number of resistant organisms' colonization and may be an attractive substitution for antibiotics for prophylaxis in future [16]. Non-antibiotic prophylaxis may be used for preventing UTI. Some studies may recommend cranberry juice as prophylaxis of UTI, but there is not any reliable clue to prove its effectiveness [9]. In Linsenmeyer's study, cranberry was used for prophylaxis of UTI in patients with neurogenic bladder after spinal cord injury. Cranberry tablets could not effectively decrease the risk of UTI in patients with neurogenic

Infectious Complications after Spinal Cord Injury http://dx.doi.org/10.5772/intechopen.72783 95

One of the most important, serious, and chronic complications of spinal cord injury is pressure ulcer [22]. Pressure ulcers may cause long-term morbidity and even mortality and effectively have severe influence on SCI patients' lives [23]. These patients have more risk of developing pressure ulcer. The ulcers are often chronic wounds that debilitate the patient and increase hospital course [24]. Pressure ulcers are common in SCI patients and usually are complicated. Treatment is often difficult and expensive. It is important to pay special attention to pressure ulcer in SCI population [25]. Several risk factors are associated with pressure ulcer. These risk factors include: decreased activity, complete cord injury that cause paralysis, cervical collar and back board that cause restricted activity, diabetes mellitus, cigarette smoking, hypoalbuminemia, nursing home residence or long duration hospital stay [26], loss of sensation, wet area due to urinary or fecal incontinence, poor nutrition, and muscular atrophy. Pressure ulcers usually occur in about 30–40% of SCI patients. Ulcers usually develop on bony prominences. Sacrum, ischial tuberosity, trochanteric area and malleolus are usual areas for developing ulcers [2]. Patients with pressure ulcers may have good outcomes if rapid diagnosis and proper treatment is performed for them. The ulcer may heal completely without any sequelae. Some ulcers may have slow course of healing and some even may not heal. Some studies emphasize on the role of fibronectin on ulcer healing course. Fibronectin may have a role in opsonizing macro-aggregate debris for phagocytosis, increasing revascularization, and facilitating fibroblast proliferation and migration. Plasma fibronectin increases in ulcers

## *2.1.2. Treatment*

Differentiating infection from colonization and asymptomatic bacteriuria from symptomatic infection is an important point in treatment of UTI in SCI patient. A symptomatic patient needs to be treated, and after treatment, long duration of antibiotic suppressive therapy is not necessary [17]. For treatment of UTI, usually, there are many antibiotic options. It is better to postpone the treatment until the result of culture. Sometimes it is necessary to treat the patient empirically. Some variables like probable organism and susceptibility, administration route (oral vs. intravenous), the patient tolerance, renal function, and the patients' other medications should be considered for choosing appropriate antibiotic [19]. Duration of treatment of chronic UTI in SCI patient may need to be extended. Some studies recommend and some do not. It seems more studies are needed for certain recommendations [10]. The best antibiotics are those that have the most therapeutic effect on causative agent, without any or with less impact on the host normal flora. This antibiotic is best chosen according to result of urine culture and antibiogram. Duration of treatment is usually 5 days but may be extended to 7–14 days when reinfection or relapse occurs [9]. Some studies recommend treating urinary infection between 10 and 14 days in SCI patients, especially when it is not possible to discontinue the urinary catheter. To determine the optimal duration of treatment, multicentral and randomized clinical trial may be necessary [19]. Darouiche's study demonstrates that the 5-day treatment with urinary catheter exchange can be as effective as a 10-day regimen with catheter retention [20]. Antibiotics usually are chosen according to urine culture. Third generation of cephalosporines, carbapenems, and quinolones are often used to treat Gram-negative organisms. For treatment of *Enterococcus* and *Staphylococcus aureus* that usually are resistant in these patients (i.e., methicillin-resistant *S. aureus* or MRSA), vancomycin is appropriate.

#### *2.1.3. Prevention and prophylaxis*

*2.1.1. Diagnosis*

94 Essentials of Spinal Cord Injury Medicine

*2.1.2. Treatment*

mycin is appropriate.

disorder for optimal treatment success [9].

Diagnosis of UTI is usually based on the results of urine culture, although in some condition like low titer of organism in urine, slow-growing pathogens and unusual organisms, results of culture may be unreliable [12]. The physician should be aware of how to diagnose UTI and distinguish it from colonization. These patients are at increased risk of acquiring multidrug-resistant bacteria because they are admitted due to UTI or other infectious diseases and take antibiotics. Several resistant organisms may cause UTI in SCI patients including multidrug-resistant *Pseudomonas aeruginosa*, ESBL (extended-spectrum β-lactamase-producing) *Escherichia coli*, resistant *Klebsiella* spp. and MRSA (methicillin-resistant *Staphylococcus aureus*) [10]. Due to multiple risk factors for acquisition of infection, especially with resistant organisms, complicated UTI may develop with unusual and resistant bacteria. The infection may be polymicrobial. Proteus, Providencia, Serratia, and enterococci may also cause UTI in these groups [9]. For the diagnosis of UTI, culture is needed to find to causative agent, but if the patient is not symptomatic, it is not necessary to get culture, because the patients usually do not need treatment [17]. When UTI is diagnosed in SCI patient, the physician should evaluate the patient for anatomical and functional disorders. It is important to correct any correctable

Differentiating infection from colonization and asymptomatic bacteriuria from symptomatic infection is an important point in treatment of UTI in SCI patient. A symptomatic patient needs to be treated, and after treatment, long duration of antibiotic suppressive therapy is not necessary [17]. For treatment of UTI, usually, there are many antibiotic options. It is better to postpone the treatment until the result of culture. Sometimes it is necessary to treat the patient empirically. Some variables like probable organism and susceptibility, administration route (oral vs. intravenous), the patient tolerance, renal function, and the patients' other medications should be considered for choosing appropriate antibiotic [19]. Duration of treatment of chronic UTI in SCI patient may need to be extended. Some studies recommend and some do not. It seems more studies are needed for certain recommendations [10]. The best antibiotics are those that have the most therapeutic effect on causative agent, without any or with less impact on the host normal flora. This antibiotic is best chosen according to result of urine culture and antibiogram. Duration of treatment is usually 5 days but may be extended to 7–14 days when reinfection or relapse occurs [9]. Some studies recommend treating urinary infection between 10 and 14 days in SCI patients, especially when it is not possible to discontinue the urinary catheter. To determine the optimal duration of treatment, multicentral and randomized clinical trial may be necessary [19]. Darouiche's study demonstrates that the 5-day treatment with urinary catheter exchange can be as effective as a 10-day regimen with catheter retention [20]. Antibiotics usually are chosen according to urine culture. Third generation of cephalosporines, carbapenems, and quinolones are often used to treat Gram-negative organisms. For treatment of *Enterococcus* and *Staphylococcus aureus* that usually are resistant in these patients (i.e., methicillin-resistant *S. aureus* or MRSA), vancoPrevention of UTI in SCI patients plays an important role in hospital and even in rehabilitation courses of these patients. Paying attention to urinary tract hygiene is necessary. Some patients may encounter relapse or reinfection. In these patients, evaluation of structural and functional disorders should be performed. Duration of previous treatment and probable complications like urine residue and urinary stone should be assessed. Antibiotics may be used as prophylaxis, but it is important to notice that it can be used when recurrent UTI occurs and when all structural and functional abnormalities are corrected. Prophylaxis is not recommended for patients carrying indwelling catheters, and for those who have intermittent catheterization, it is contraventional [9]. Physicians can most effectively prevent UTI by avoiding use of longterm catheters, short duration of catheter use, and substituting intermittent catheterization with indwelling catheter. Daily washing of the catheter or perianal or periurethral areas has no preventive effect. It is recommended to use antibiotic immediately before any invasive procedure on urinary tract system [19]. Probiotics may be useful as prophylactic agents. They may decrease the number of resistant organisms' colonization and may be an attractive substitution for antibiotics for prophylaxis in future [16]. Non-antibiotic prophylaxis may be used for preventing UTI. Some studies may recommend cranberry juice as prophylaxis of UTI, but there is not any reliable clue to prove its effectiveness [9]. In Linsenmeyer's study, cranberry was used for prophylaxis of UTI in patients with neurogenic bladder after spinal cord injury. Cranberry tablets could not effectively decrease the risk of UTI in patients with neurogenic bladders [21].

#### **2.2. Skin and soft tissue infection**

One of the most important, serious, and chronic complications of spinal cord injury is pressure ulcer [22]. Pressure ulcers may cause long-term morbidity and even mortality and effectively have severe influence on SCI patients' lives [23]. These patients have more risk of developing pressure ulcer. The ulcers are often chronic wounds that debilitate the patient and increase hospital course [24]. Pressure ulcers are common in SCI patients and usually are complicated. Treatment is often difficult and expensive. It is important to pay special attention to pressure ulcer in SCI population [25]. Several risk factors are associated with pressure ulcer. These risk factors include: decreased activity, complete cord injury that cause paralysis, cervical collar and back board that cause restricted activity, diabetes mellitus, cigarette smoking, hypoalbuminemia, nursing home residence or long duration hospital stay [26], loss of sensation, wet area due to urinary or fecal incontinence, poor nutrition, and muscular atrophy. Pressure ulcers usually occur in about 30–40% of SCI patients. Ulcers usually develop on bony prominences. Sacrum, ischial tuberosity, trochanteric area and malleolus are usual areas for developing ulcers [2]. Patients with pressure ulcers may have good outcomes if rapid diagnosis and proper treatment is performed for them. The ulcer may heal completely without any sequelae. Some ulcers may have slow course of healing and some even may not heal. Some studies emphasize on the role of fibronectin on ulcer healing course. Fibronectin may have a role in opsonizing macro-aggregate debris for phagocytosis, increasing revascularization, and facilitating fibroblast proliferation and migration. Plasma fibronectin increases in ulcers with rapid healing but stay in low level in ulcers with poor healing. So plasma fibronectin level may predict the speed of healing of pressure ulcers [27]. The SCI patients may also suffer from other soft tissue infection rather than pressure ulcers including fungal infections and seborrheic dermatitis [28].

the risk of pressure ulcer development. The risk of developing pressure ulcer is highly individualized and the SCI patient is at a significant risk. Prevention strategies in seating position and in bed are very important in this group to prevent pressure ulcer, and so, pressure relief maneuvers can be important [35]. Pressure relief, position changes, and regular and frequent observation of skin, especially on the pressure areas, that is, over the bony prominences can prevent pressure ulcer development [2]. Pressure ulcers can also be prevented by improvement of neurologic functions and reducing the time of hospitalization and rehabilitation stay [36]. Pressure ulcer prevention is strongly associated with lifestyle modification [35]. Frequent change of position and use of pressure-relieving devices have important roles in reducing the pressure ulcer development. Some risk factors other than pressure may be important in developing ulcer. In SCI patients who do not have vasomotor control below the level of the lesion, hypoxemia will develop, and it can be an important risk factor. So, pressure ulcers may be prevented not only by reducing external pressure by pressure relief, but also by increasing the patient's resistance to pressure, by increasing tissue oxygenation [37]. One of the important risk factors that may increase skin and soft tissue infections is resistant bacterial colonization. Some activities such as hand hygiene, contact precautions, and cultural changes are associated with significant declines in bacterial infection, especially MRSA colonization and

Infectious Complications after Spinal Cord Injury http://dx.doi.org/10.5772/intechopen.72783 97

One of the complications of spinal cord injury is osteomyelitis. Osteomyelitis may develop by extension of infection from pressure ulcers [38]. After spinal fixation surgery, osteomyelitis may be developed, as a complication of surgery. Osteomyelitis increases the treatment cost

Bone biopsy is the gold standard, and magnetic resonance imaging (MRI) is usually used as a sensitive and specific modality. Several organisms are known as causative agents. The most common isolated organisms are *Staphylococcus aureus*, Peptostreptococcus, and Bacteroides. Coagulasenegative staphylococci, group B Streptococcus, Proteus, and group milleri Streptococcus may also be isolated as less common agents. The diagnosis of pelvic osteomyelitis is difficult and may need multiple bone biopsies. At least three bone samples may be necessary to detect the pathogen and exclusion of contamination. In one study, sensitivity of MRI for diagnosis of pelvic

However, Huang's study demonstrates that MRI is a sensitive method for diagnosis of osteomyelitis in SCI population. MRI can be used to demonstrate the extension of infection and to guide limited surgical resection and preserve viable tissue [41]. Pelvic pressure ulcers that accompany osteomyelitis may show cortical erosion and bone marrow edema in MRI [42]. In SCI patients, abscesses, fluid collections, and sinus tracts can be detected by MRI [43]. For diagnosis of osteomyelitis, gallium scan and plain pelvis X-ray may be used. Negative bone

There are several diagnostic methods for diagnosis of osteomyelitis in SCI patients.

pressure ulcer osteomyelitis was 94% and specificity was 22% [40].

infection [28].

**2.3. Osteomyelitis**

*2.3.1. Diagnosis*

and may lead to other complications [39].

#### *2.2.1. Diagnosis*

Diagnosis of pressure ulcers is clinical. The ulcer smear and culture can be useful for recognizing the causative organism and determining the antibiotic sensitivity. *Staphylococcus aureus*, *Pseudomonas aeruginosa*, *Proteus mirabilis*, and *Enterococcus faecalis* are the most common organisms causing pressure ulcers [24].
