Page 57 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

26 PART 1: An Overview of the Approach to and Organization of Critical Care

respiratory equipment has been implicated as the source of outbreaks Staphylococcus aureus being the most common organisms identified. 49,50
of nosocomial pneumonia. Devices that generate aerosols, such as Prevention involves avoiding nasotracheal intubation, placing feeding
nebulizer reservoirs used for humidification and multidose medication tubes through the mouth rather than through the nose, and minimizing
41
nebulizers, have been associated with outbreaks caused by hydrophilic sedative use.
42
bacteria. Bronchoscopes have also been a source of health care–associ-
ated pneumonia in the ICU, usually as a result of an incomplete or com- ■ INTRACRANIAL PRESSURE MONITORING DEVICES
promised disinfection between procedures. 43 Several infectious complications can result from the use of intracra-
Guidelines for the prevention of ventilator-associated pneumonia nial pressure monitoring devices, including scalp exit-site and tunnel
focus on proper hand hygiene when handling respiratory equipment, infections, osteomyelitis of the calvarium, meningitis, and ventriculi-
nursing ventilated patients in a semirecumbent position (30° to 45°), tis. The rate of infectious complications has been reported at 7.4% to
and maintaining a closed ventilator circuit (Table 4-3). The use of 14.1% per procedure. 51,52 Intracerebral or intraventricular hemorrhage,
44
noninvasive ventilation in selected ICU patients results in a lower risk cerebrospinal fluid leaks, open head injuries, monitors in place for
of pneumonia when compared with endotracheal mechanical ventila- greater than 5 days, breaks in the pressure transducer system, and use
tion. In a randomized, clinical trial, patients ventilated noninvasively of intraventricular versus intraparenchymal monitors have been associ-
had a significantly lower rate of both pneumonia (3% vs 25%) and ated with increased risk of infection. Coagulase-negative staphylococci
sinusitis (0% vs 6%). Subglottic suctioning of oropharyngeal secre- are the most common cause of intracranial pressure monitor–related
45
tions using a specially designed endotracheal tube has been shown infections, but gram-negative bacilli, such as Acinetobacter baumannii,
to reduce the incidence of ventilator-associated pneumonia and is Klebsiella pneumoniae, and Proteus mirabilis, have been reported in up
another method to reduce the risk of nosocomial pneumonia among to 50% of cases. The role of prophylactic antibiotic therapy is unclear.
53
ventilated patients. The use of silver-coated endotracheal tubes has Several cohort studies showed no impact on the incidence of infection
46
been shown to reduce the incidence of ventilator-associated pneumo- among patients who received antibiotics during or after insertion of the
nia and mortality. 47,48 devices, 52,54 but no randomized, controlled trials of sufficient sample size
The presence of a foreign body in the nasopharynx, such as a naso- exist to address the question. Routine preventive measures including
gastric feeding tube, predisposes to upper airway infections, particularly maximal barrier precaution during insertion, routine dressing changes,
sinusitis. Health care–associated sinusitis is often difficult to diagnose. and use of antimicrobial impregnated intraventricular catheter may
First, the classic signs and symptoms of sinusitis (ie, sinus tenderness, reduce catheter-related ventriculitis. 55
pain, and fever) often are masked in the intubated and sedated patient.
Also, sinus aspiration to determine if a sinus fluid collection is infected
is performed only rarely. In a prospective study, paranasal sinus com- INTERVENTIONS TO PREVENT HEALTH
puted tomographic (CT) scans were obtained on all ICU patients with CARE–ASSOCIATED INFECTIONS
purulent nasal discharge and fever not attributable to another source, Interventions designed to reduce health care–associated infections
followed by sinus aspiration and culture of any fluid observed on CT typically focus on device-related infection, are evidence based, and
scan. Using this method, sinusitis was identified in 7.7% of patients. often employ physician and nursing education or introduce a change in
49
Risk factors for nosocomial sinusitis include nasotracheal intubation, the process of care. An intervention consisting of a self-study module
feeding via nasogastric tube, and impaired mental status. These infec- on risk factors for catheter-associated infections, a pre- and posttest
tions frequently are polymicrobial, with Pseudomonas aeruginosa and assessment of knowledge, posters and handouts on the infection control
practices related to central venous catheters, and didactic teaching were
given to the nursing staff of a surgical ICU. The authors reported a
28
TABLE 4-3 Selected Guidelines for the Prevention of Ventilator-Associated Pneumonia 66% reduction in the incidence of ICU-acquired bloodstream infec-
• Educate health care workers regarding health care–associated pneumonia and infection tions in the 18-month period after the intervention compared with the
prevention and prevention methods. 18 months preintervention (p <0.001), without a significant change
• Use hand hygiene before and after contact with patient, respiratory devices, or objects in the patient population. This study demonstrates that focused inter-
contaminated with respiratory secretions. vention in ICUs can reduce health care–associated infections, possibly
through changes in ICU practice and staff behavior.
• Do not routinely change ventilator breathing circuit components more frequently than Another practice designed to prevent health care–associated infec-
every 48 hours. tion is selective digestive decontamination. The hypothesis behind this
• Periodically drain condensate from mechanical ventilator tubing; avoid draining of con- practice is that colonization of the oropharynx and gastrointestinal
densate toward the patient. tract by flora acquired while a patient is in the ICU serves as a source
• Use sterile water to fill bubbling humidifiers and nebulizers. of health care–associated infection, particularly in patients requiring
prolonged ICU stays and mechanical ventilation. By administering
• Do not use large-volume room-air humidifiers unless they undergo daily high-level oral, nonabsorbable antibiotics, selective digestive decontamination
disinfection; use sterile water in device.
seeks to prevent the overgrowth of gram-negative aerobic bacteria and
• Devices used on multiple patients (eg, portable respirators, oxygen sensors, Ambu bags) yeast while maintaining anaerobic flora. The method has been useful
should undergo sterilization or high-level disinfection between patients. in controlling outbreaks of resistant gram-negative bacteria. Studies
56
• Thoroughly clean respiratory equipment prior to disinfection or sterilization. of its routine use have had conflicting results, with more methodologi-
cally rigorous studies tending to show no benefit in terms of prevent-
• Use aseptic technique when changing a tracheostomy tube.
ing health care–associated pneumonia or mortality. 57,58 A randomized
• Use only sterile fluid to remove secretions from respiratory suction catheter. controlled trial demonstrated the survival benefit for ICU patients
• Keep head of bed elevated at an angle of 30° to 45° and semirecumbent position for who received either selective digestive tract decontamination or selec-
patients on a ventilator or receiving enteral tube feedings, if possible. tive oropharyngeal decontamination. However, follow-up study in
59
the same population showed selective digestive tract decontamina-
• Discontinue mechanical ventilation and enteral tube feedings as soon as clinically feasible.
tion or selective oropharyngeal decontamination was associated with
• Perform regular antiseptic oral care. inducing antimicrobial resistance. The benefit and risk of selective
60
• Use an endotracheal tube with in-line and subglottic suctioning for all eligible patients. digestive tract decontamination or selective oropharyngeal decon-
Data from Coffin SE, Klompas M, Classen D, et al. Strategies to prevent ventilator-associated pneumonia tamination in the ICU should be discussed before implementing these
in acute care hospitals. Infect Control Hosp Epidemiol. October 29, 2008;(suppl 1):S31-S40. interventions.

Section01.indd 26 1/22/2015 9:36:47 AM