Nosocomial infections, or health care–associated infections (HCAI), are a global problem. The basis of success of any effort for decreasing HCAI rates is the compliance of health care providers with preventive measures. Neurocritical care patients have some features, which hypothetically are able to increase the rates of HCAI. These risk factors are divided into modifiable and nonmodifiable. Neurocritical care specialists should be aware of these factors and try to decrease their influence on the rates of HCAI. Universal precautions in the neuro–intensive care unit are referred, first of all, to the prophylactics and treatment of HCAI. This can lead to improvement of results of patients in the intensive care.
KeywordsAntibiotics, Microbiology, Neurocritical care, Nosocomial infection, Universal precautions
Nosocomial infections, or health care–associated infections (HCAI), are a global problem. The Centers for Disease Control and Prevention (CDC) reported 1.7 million HCAI cases in the United States in 2007. During the past decade reliable success in HCAI prevention was achieved for bloodstream infections only. A cardinally opposite situation is observed for other kinds of HCAI, and the rates of sepsis are increasing annually by 1.5%. In developing countries, the situation with HCAI is much sorer. The basis of success of any effort for decreasing HCAI rates is compliance of health care providers with preventive measures.
Microbial polyresistance indivisibly interlaces with the problem of HCAI. Since the 1940s, when penicillin was discovered, we could create first-class both gram-positive and gram-negative multidrug-resistant (MDR) pathogens: Enterococcus faecium , Staphylococcus aureus , Klebsiella pneumonia , Escherichia coli , Acinetobacter baumannii , Pseudomonas aeruginosa , Enterobacter spp, and many others. One of the major reasons of multidrug resistance formation is selection pressure, which is a result of inappropriate strategy and tactics of antibiotic therapy.
Neurocritical care patients have some features that hypothetically are able to increase the rates of HCAI. These risk factors are divided into modifiable and nonmodifiable. Modifiable factors include antibiotic therapy, duration of neurosurgical operation, duration of external cerebrospinal fluid (CSF) drainage, and tactics of care for external CSF drainage. Nonmodifiable factors include the type of pathology (for example, stroke or neuroleukemia) and recent chemotherapy. Neurocritical care specialists should to be aware of these factors and try to decrease their influence on the rates of HCAI.
Thus, universal precautions in the neuro–intensive care unit (ICU) refer, first, to the prophylactics and treatment of HCAI. This can lead to improvement in results of patients in the ICU.
Prophylactics of Health Care–Associated Infections in the Intensive Care Unit
In accordance with the largest multicenter study, in 2014, 4% patients (452 among 11,282 patients) had HCAI during their course of hospitalization. The rate of HCAI in ICUs is much higher. The strategy of effective prophylactics of HCAI implies definite accentuation of three components in the ICU setting: patient, patient’s surroundings, and intensive care providers (hands and clothing of the ICU stuff). These components should be separated with special barriers. Correct construction of reliable barriers is one of the major precautions in the neuro-ICU.
Cross-transmission of pathogens is a leading cause of infection in the ICU, and ICU stuff is a principle bacteria carrier. This is a cornerstone thought in the concept of infection control. Hand hygiene holds a central position in the prevention of cross-transmission of pathogens, and therefore this is a universal precaution in the neuro-ICU. According to the CDC and World Health Organization guidelines on hand hygiene, alcohol-based handrub should be used in the preferred manner for routine hand washing. Alcohol-based antiseptics have acceptable effectiveness against a majority of pathogens, which are spreading in the ICUs, including gram-positive and gram-negative MDR bacteria, a variety of fungi, and most viruses. Simultaneously alcohol-based antiseptics are completely safe for intensive care providers and should be routinely used during duty. Hand hygiene is the effective, most simple, and cheapest method for HCAI prophylactics.
Gowns and other medical clothing can be another important resource of nosocomial bacteria. A 2015 study has shown that problematic pathogens were identified in more than half of the cases of medical clothing investigations. These data demonstrate the importance of routine use of disposable nonsterile aprons or gowns. Therefore this is another important universal precaution in the neuro-ICU. The main barrier in the effectiveness of hand hygiene and usage of disposable medical clothing is the intensive care providers’ compliance, which must be at least 75–80%. If the ICU achieved this level of compliance, hospitalized patients have a reliable protection against HCAI.
Gloves should be used in a correct way. Hands must be compulsorily washed with alcohol-based antiseptics immediately before and after gloves usage, regardless of the use of sterile or nonsterile gloves. Sterile gloves are employed only in situations of contact with sterile fluids and body cavities. Otherwise usage of nonsterile disposable gloves is a fairly adequate precaution method. There are some situations in the intensive care when gloves are not needed, for example, noninvasive blood pressure measurement, skin temperature probe placement, feeding of patient with spoon, and working with patient’s surroundings.
The second component of the three-component model is the patient himself and his invasive devices—catheters, tubes, and probes. Patient, colonized with nosocomial bacteria, is a reservoir of these bacteria. Skin, oral cavity, tracheobronchial tree, and intestine are the most important sources of bacteria, which could be a cause of both a new infection of the same patient and infection of another patients. Oral cavity and teeth hygiene, usage of closed suction systems, and daily bathing with 2% or 4% chlorhexidine should be routinely done in the ICU, in spite of all these methods obtaining a different degree of evidence.
All invasive devices commonly used in the ICU, can lead to HCAI. Routine work with venous catheters, urine catheters, and gastric tube should be regulated with local protocols, which must be created in every ICU. A good example of the effectiveness of such protocols is the guidelines for the prevention of bloodstream infection in patients with venous catheters. The creation and compliance with local protocols of management of external CSF drainage is a much more important issue for the neuro-ICU, because they are able to prevent the development of central nervous system (CNS) infection. External CSF drainage is common in the neurocritical care settings. Drainage is an independent risk factor of CNS infection. There are two peaks of CNS infection associated with external CSF drainage: on the 5th day and on the 9th–12th day. Other important risk factors of CNS infection, associated with external CSF drainage, are disconnection of drainage line and irrigation of the drainage with or without intrathecal injection of antibiotics, fibrinolytics, or other medications. Therefore drainage must be removed as early as possible, and it is important to prevent any disconnection of the drainage line. This tactics is a universal precaution in the neuro-ICU.
The last component of the three-component model of prophylactics of HCAI in the ICU is the patient’s surroundings, which includes bed, bedclothes, ventilator, monitors, infusion pumps, and many others machines and devices. All these things, which always surround the patient and his bed in the ICU, could become a reservoir of nosocomial pathogens. Consequently, all devices and things, which are part of the patient’s surroundings, must be cleanable and sterilizable. Thus, it is difficult to overestimate the significance of current and final cleaning of surroundings of the patient in the ICU. There are two important conditions that should be kept in mind: proper regimen of the cleanings and correct choice of disinfectants.
Therefore all the aforementioned manipulations, performed in light of the concept of the three-component model of HCAI prophylactics, are universal precautions in the ICU.
Early Diagnosis of Pathogens and Infection Complications in the Intensive Care Unit
Early identification of the pathogens is extremely important. Simultaneously traditional microbiological methods and such novel diagnostic techniques as real-time multiplex polymerase chain reaction or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry should be performed. Novel methods can identify pathogens and give physicians preliminary information regarding bacterial resistance during 1–2 h. This allows deciding about initial antibiotic therapy and saves priceless time in the clinical situations, characterized with life-threatening conditions due to sepsis or CNS infection. However, definite judgment regarding antibacterial sensitivity and correct antibiotic therapy should be based on classic microbiological studies.
Discrimination between infection and colonization is a relevant clinical question. Infection always presents a combination of identified pathogens and clinical picture of appropriate inflectional process (pneumonia, CNS infection, uroinfection, etc.). Colonization means verified pathogens without signs of infection process. Infection must be treated with antibiotics, and the sooner the better. To treat or not to treat colonized patient with antibiotics is a difficult question. As usual such patients do not need antibiotic treatment, but surveillance only. However, some patients, colonized with MDR pathogens, do really need proper antibiotic treatment, especially if due to any reason there is a high risk of these pathogens spreading over the ICU. This is always a complex situation and a difficult decision, which must be every time balanced between benefit and harm. However, antibiotic therapy of a patient colonized with MDR pathogens could be determined as a precaution in the ICU. A special checklist for the identification patients with MDR pathogens was created. It includes the following risk factors: hospital admission lasting >5 days, during the past 3 months; institutionalized (prison, health care and social centers, geriatric centers, etc.); known colonization or infection with MDR pathogens; antibiotic therapy ≥7 days in the previous month (particularly third- and fourth-generation cephalosporins, fluoroquinolones, and carbapenems); end-stage renal disease under chronic hemodialysis or ambulatory peritoneal dialysis; and comorbidities associated with high incidence of colonization or infection with MDR pathogens such as cystic fibrosis, bronchiectasis, chronic skin ulcers, etc.
This checklist should be used for the stratification of patients and revealing among them those who might need antibiotics even in the absence of an infectious process.