9-18-2013

Ancef cefazolin 1g iv q8h
Keflex cefalexin 1g iv q8h

healthcare acquired pneumonia
current treatment: vancomycin(15 to 20 mg/kg [based on actual body weight] intravenously every 8 to 12 hours)+ceftazidime(2 g intravenously every 8 hours)

• Hospital-acquired (or nosocomial) pneumonia (HAP) is pneumonia that occurs 48 hours or more after admission and did not appear to be incubating at the time of admission.
• Ventilator-associated pneumonia (VAP) is a type of HAP that develops more than 48 to 72 hours after endotracheal intubation.
• Healthcare-associated pneumonia (HCAP) is defined as pneumonia that occurs in a non-hospitalized patient with extensive healthcare contact, as defined by one or more of the following:

• Intravenous therapy, wound care, or intravenous chemotherapy within the prior 30 days
• Residence in a nursing home or other long-term care facility
• Hospitalization in an acute care hospital for two or more days within the prior 90 days
• Attendance at a hospital or hemodialysis clinic within the prior 30 days

Specific antimicrobial considerations — In critically ill patients, in those receiving antibiotics prior to the onset of pneumonia, and in institutions where these pathogens are frequent, coverage of methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and antibiotic-resistant gram-negative bacilli, such as Acinetobacter spp, and Legionella should be considered.
Empiric treatment 
No known multidrug resistance risk factors
one of the following intravenous antibiotic regimens

• Ceftriaxone (2 g intravenously daily).
• Ampicillin-sulbactam (3 g intravenously every six hours).
• Levofloxacin (750 mg intravenously daily) or moxifloxacin (400 mg intravenously daily). When the patient is able to take oral medications, either agent may be administered orally at the same dose as that used for IV administration.
• Ertapenem (1 g intravenously daily)

Known multidrug resistance risk factors — Host risk factors for infection with multidrug-resistant (MDR) pathogens include receipt of antibiotics within the preceding 90 days, current hospitalization of ≥5 days, high frequency of antibiotic resistance in the community or in the specific hospital unit, immunosuppressive disease and/or therapy, and presence of risk factors for HCAP.

ONE of the following:

• Antipseudomonal cephalosporin such as cefepime (2 g intravenously every eight hours) or ceftazidime (2 g intravenously every 8 hours).
• Antipseudomonal carbapenem such as imipenem (500 mg intravenously every six hours) or meropenem (1 g intravenously every eight hours) or doripenem (500 mg intravenously every eight hours; administered over one hour for HAP or HCAP, administered over four hours for VAP) [53,54].
• Piperacillin-tazobactam (4.5 g intravenously every six hours).
• For patients who are allergic to penicillin, the type and severity of reaction should be assessed. The great majority of patients who are allergic to penicillin by skin testing can still receive cephalosporins (especially third-generation cephalosporins) or carbapenems. If there is a history of a mild reaction to penicillin (not an IgE-mediated reaction, Stevens Johnson syndrome or toxic epidermal necrolysis), it is reasonable to administer a cephalosporin or carbapenem using a simple graded challenge (eg, give 1/10 of dose, observe closely for 1 hour, then give remaining 9/10 of dose, observe closely for 1 hour). Skin testing is indicated in some situations. If a skin test is positive or if there is significant concern to warrant avoidance of a cephalosporin or carbapenem, aztreonam (2 g intravenously every six to eight hours) is recommended. Indications and strategies for skin testing are reviewed elsewhere. (See "Penicillin-allergic patients: Use of cephalosporins, carbapenems, and monobactams".)
• Patients with past allergic reactions to cephalosporins may also be treated with aztreonam, with the possible exception of those allergic to ceftazidime. Ceftazidime and aztreonam have similar side chain groups, and cross reactivity between the two drugs is variable. The prevalence of cross-sensitivity has been estimated at <5 percent of patients, based upon limited data. Patients with past reactions to ceftazidime that were life-threatening or suggestive of anaphylaxis (involving urticaria, bronchospasm, and/or hypotension) should not be given aztreonam unless evaluated by an allergy specialist. In contrast, a reasonable approach in those with mild past reactions to ceftazidime (eg, uncomplicated maculopapular rash) would involve informing the patient of the low risk of cross-reactivity and administering aztreonam with a graded challenge (1/100, 1/10, full dose, each separated by 1 hour of observation).

PLUS consider adding one of the following

• Antipseudomonal fluoroquinolone, preferred regimen if Legionella is likely, such as ciprofloxacin (400 mg intravenously every eight hours) or levofloxacin (750 mg intravenously daily). These agents may be administered orally when the patient is able to take oral medications. The dose of levofloxacin is the same when given intravenously and orally, while the dose of ciprofloxacin is 750 mg orally twice daily.
• Aminoglycoside such as gentamicin or tobramycin (7 mg/kg intravenously once daily) or amikacin (20 mg/kg intravenously once daily); once daily dosing is only appropriate for patients with normal renal function. A single serum concentration should be obtained 6 to 14 hours after the first dose, and the dose should be adjusted as needed based upon the following nomogram (figure 1). The aminoglycoside can be stopped after five to seven days in responding patients. (See "Consolidated aminoglycoside dosing with gentamicin and tobramycin".)
• Addition of an alternative agent, such as intravenous colistin, may be appropriate if highly resistant Pseudomonas spp or Acinetobacter spp is suspected (see "Treatment of Pseudomonas aeruginosa infections", section on 'Alternative therapy in multidrug resistant infections' and "Acinetobacter infection: Treatment and prevention", section on 'Pneumonia' and "Colistin: An overview", section on 'Systemic administration') [56]. In some cases, inhaled colistin may be appropriate as adjunctive therapy in combination with systemic antimicrobials, as discussed below. 

PLUS ONE of the following (if MRSA is suspected, there are MRSA risk factors, or there is a high incidence of MRSA locally):

• Linezolid (600 mg intravenously every 12 hours; may be administered orally when the patient is able to take oral medications)
• Vancomycin (15 to 20 mg/kg [based on actual body weight] intravenously every 8 to 12 hours for patients with normal renal function, with a target serum trough concentration of 15 to 20 mg/L.) In seriously ill patients, a loading dose of 25 to 30 mg/kg can be used to facilitate rapid attainment of the target trough concentration. 

RECOMMENDATIONS FOR USE OF ZOSTER VACCINE

General recommendations — The zoster vaccine (Zostavax; Merck Pharmaceuticals) has been approved for use in the United States, Europe, and Australia. The United States Advisory Committee on Immunization Practices (ACIP) voted to recommend herpes zoster vaccination for all people aged 60 years and older in 2006 [20].

In 2011, the Food and Drug Administration (FDA) approved the use of zoster vaccine among persons 50 to 59 years of age based on preliminary efficacy data from a randomized clinical trial [19]. In June 2011 the Advisory Committee on Immunization Practices declined to recommend zoster vaccine in this age group, citing concerns regarding shortfalls of zoster vaccine for general use [21]. (See 'Adults 50 to 59 years of age' above.)

Zoster vaccine is NOT indicated for the treatment of zoster or post-herpetic neuralgia.

Formulation and administration — The zoster vaccine is a live-attenuated vaccine, which is administered as a one-time subcutaneous injection. The vaccine contains 18,700 to 60,000 plaque-forming units of virus, considerably more than the approximately 1350 plaque-forming units found in the Oka/Merck VZV vaccine for prevention of varicella [22].

Pneumococcal polysaccharide vaccine (PPSV, Pneumovax) and zoster vaccine should be separated by at least 4 weeks because the administration of PPSV may reduce the immunogenicity of zoster vaccine [23,24]. In situations where separating the vaccines by 4 weeks would be a barrier to vaccination, the Centers for Disease Control suggests giving the vaccines together [25,26]. This recommendation is based on data from an observational study that did not find a difference in the rate of herpes zoster among those who received the vaccines concurrently, compared to those who had the vaccines separated by 4 weeks [27].

Serologic testing — It is not necessary to elucidate whether the patient has a history of varicella prior to vaccine administration. Serologic testing for past exposure to VZV prior to immunization is also not required since it was not utilized in the large clinical trials described above [20,28,29].

The reader is referred elsewhere for details on the sensitivity and specificity of serologic testing. (See "Diagnosis of varicella-zoster virus infection".)

Use in patients with prior zoster — The Centers for Disease Control and Prevention and the ACIP recommend a single dose of zoster vaccine for adults aged >60 years, regardless of whether the patient has reported a prior episode of herpes zoster [30,31].

However, it is unclear if zoster vaccine offers any clear benefit among those with a recent history of herpes zoster. One retrospective study of 1036 vaccinated and 5180 unvaccinated persons >60 years of age with a history of zoster within the past four years found that the incidence of recurrent disease was low; only 29 well-documented cases were discovered on chart review during the 4.5 years of follow-up [32]. The low number of events precluded any definitive analysis of vaccine efficacy in prevention of zoster recurrence, though there was a trend toward lower rates among vaccinated patients. The scarcity of cases among persons with recent zoster may be related to endogenous boosting of VZV-specific T cells during reactivation disease.

Contraindications — Zoster vaccine is NOT advised for use in pregnant women or in individuals with a history of an anaphylactic reaction to gelatin or neomycin [33].

Zoster vaccine is also NOT advised in patients with primary or acquired immunodeficiencies (including leukemia, lymphoma, or other malignancies affecting the bone marrow or lymphatic system), AIDS, and patients on immunosuppressive therapies, since it is a live attenuated vaccine [34]. The use of zoster vaccine in the patient who is going to initiate immunosuppressive therapy is discussed below. (See 'Vaccination before immunosuppression' below.)