Healthcare-Associated Infections _ ______________________________________________________________
the right lung improved the diagnostic accuracy of bronchoal- veolar lavage [198; 224; 225]. However, the invasive procedure has disadvantages, including high cost, need for technical expertise, and potential for false-negative results [198; 224]. The 2016 IDSA/ATS guidelines recommend collecting speci- mens from the lower respiratory tract for culture, preferably by noninvasive techniques and reliance on semiquantitative culture technique [20]. Noninvasive methods to obtain respi- ratory samples in patients with hospital-acquired (but not ventilator-associated) include spontaneous expectoration, sputum induction, nasotracheal suctioning (in a patient unable to produce a sample), and endotracheal aspiration in a patient who subsequently requires mechanical ventilation [20]. A 2012 meta-analysis (and a 2014 update) found no evidence that the use of quantitative cultures of respiratory secretions resulted in decreased mortality, reduced time in ICU and on mechani- cal ventilation, or higher rates of antibiotic change compared with qualitative cultures in patients with ventilator-associated pneumonia [226; 227]. In addition, there was no difference in mortality, whether invasive or noninvasive methods were used to obtain specimens. Treatment Treatment is complicated by two divergent needs: the need for empiric therapy with a broad-spectrum antibiotic, to aid in reducing mortality rates, and the need to avoid the indiscriminate use of antibiotics, to avoid the development of resistance. To address this complex issue, the strategy of de-escalation therapy was developed. With this treatment approach, a broad-spectrum antibiotic targeted to likely patho- gens is administered, and the antibiotic regimen is altered, if necessary, after the results of cultures are known [228; 229]. This strategy has reduced the mortality rate while achieving an overall objective of a more judicious use of antibiotics [228; 230; 231]. In one study, de-escalation therapy led to a signifi- cantly lower mortality rate compared with either escalation therapy or therapy that was neither escalated nor de-escalated (17% compared with 43% and 24%, respectively) [197]. It has been emphasized that this approach, and empiric treat- ment of healthcare-acquired pneumonia in general, calls for knowledge of the infection history of the healthcare facility and of individual patient units [193; 198; 232]. Microbiology laboratory reports can provide such details, and physicians should prescribe initial antibiotics that are likely to be active against these pathogens. The IDSA/ATS guidelines provide several recommendations for the management of both hospital-acquired and ventilator- associated pneumonia [20]: • Obtain sputum samples from the lower respiratory tract for culture before beginning antibiotic therapy. Do not delay initiation of therapy for critically ill patients in order to obtain specimens.
• Begin treatment promptly, selecting an empiric antibiotic regimen that covers S. aureus , Pseudomonas aeruginosa , and other gram-negative bacilli. • In selecting coverage for S. aureus , choose an agent active against MRSA (vancomycin or linezolid) for patients with any of the following: ‒ Risk factor for antimicrobial resistance ‒ Treatment in hospital or units where >10% of isolates are methicillin-resistant ‒ Patients in settings where the prevalence of MRSA is unknown • In selecting coverage for P. aeruginosa , one antibiotic active against this pathogen is satisfactory if the patient has no risk factors for antimicrobial resistance and <10% of gram-negative isolates from the patient’s unit are resistant to the agent chosen; otherwise, prescribe two antipseudomonal antibiotics from different classes. • Consider de-escalation of antibiotics after the results of cultures and sensitivities are known and the clinical response is satisfactory. • When an optimal antibiotic regimen is confirmed,
a seven-day course of therapy is recommended, provided the rate of improvement of clinical,
radiographic, and laboratory parameter is satisfactory. • It is suggested to use serum procalcitonin levels plus clinical criteria to guide discontinuation of antibiotic therapy, rather than clinical criteria alone.
In patients with suspected ventilator- associated pneumonia, the IDSA and the American Thoracic Society recommend including coverage for S. aureus , Pseudomonas aeruginosa , and other gram-negative bacilli in
all empiric regimens. (https://www.idsociety.org/practice-guideline/ hap_vap. Last accessed January 26, 2025.) Strength of Recommendation/Level of Evidence : Strong recommendation, low-quality evidence
Specific treatment depends on the timing of onset and the presence or absence of risk factors for infection with multi- drug-resistant organisms. For early-onset pneumonia and/or patients with no such risk factors, limited-spectrum antibiotic therapy is recommended ( Table 12 ) [20]. For late-onset pneu- monia and/or patients at increased risk for multidrug-resistant bacteria, a broad-spectrum antibiotic therapy is recommended.
94
EliteLearning.com/Dental
Powered by FlippingBook