Empiric Treatment
For all patients with ILI we recommend Osteltamivir 75
mg BID until initial NP and tracheal cultures are negative
and your local infection control officer has approved removal
of the patient from isolation. Therapy must be initiated
early, before confirmatory testing. There is a suggestion
that delayed treatment may be associated with worse outcome.
For confirmed H1N1 cases, we recommend that Osteltamivir
be continued for 10 days at 75 mg BID. For patients with
persistent viral shedding, or who are immunocomprimised,
the duration of treatment may need to be extended. Oseltamivir
should not be discontinued prior to course completion unless
the patient has a negative influenza test result (including
H1N1), another high probability pathogen is identified,
or there are toxicity concerns.
For severely ill patients higher doses of Osteltamivir
have been advocated (150 mg BID). However there is no evidence
for this practice. For patients that are at high risk for
H1N1 illness, and/or those presenting with severe disease,
who have negative initial test results with no other apparent
cause for their illness, duration of therapy should be determined
on a case by case basis (i.e. continue antiviral despite
negative test results). An ID consult for these patients
is recommended.
We recommend considering the WHO
recommendations that in situations where oseltamivir
is not available or not possible to use, or if the virus
is resistant to oseltamivir but known or likely to be susceptible
to zanamivir, patients who have severe or progressive clinical
illness could be treated with zanamivir.
Mechanical Ventilation
Non-Invasive Ventilation
Non-invasive ventilation (NIV) is currently not recommended
for severe ILI or confirmed H1N1. There is no evidence to
support its use. Early reports suggest that patients who
are severely hypoxemic typically require intubation.
The use of NIV for exacerbations of COPD caused a great
deal of discussion. These modality has been shown to be
effective in reducing the need for ICU admission and potentially
mortality. Consequently recommending against its use may
be unwarranted. Its use in COPD exacerbations (non-confirmed
H1N1) may also reduce the demand for mechanical ventilation.
Therefore the CCCS working group felt that the decision
to use NIV should be left to the discretion of the health
care team and be judged on a case by case basis. Patients
with suspected ILI and COPD should be isolated until they
are culture negative. Health care workers must wear full
personal protection, including N95 masks when NIV is being
used.
Invasive Mechanical Ventilation
Patients who are intubated for severe respiratory failure
are typically difficult to oxygenate. Their clinical behavior
is similar to children and young adults with severe viral
pneumonia. Pressure control or volume control ventilation
are recommended incorporating a lung protective strategy
to minimize ventilator induced lung injury. We recommend
consideration of an ‘open lung’ strategy recognizing
that high levels of PEEP may not be effective
Consider Airway pressure release ventilation (APRV), for
patients who remain hypoxemic (saturation < 90%) despite
FiO2 of 100% in the face of a trial of PEEP. Consider HFO,
for patients who remain hypoxemic (saturation < 90%)
despite FiO2 of 100% in the face of a trial of PEEP and
APRV. The use of (HFO should be restricted to centers that
have expertise in this area. It is unclear if HFO offers
any benefit in this population compared to conventional
MV). We strongly discourage the acquisition of HFO machines
for centers that do not have experience with this modality.
Newer HFO ventilators are not likely an aerosol generator.
Scavenging of the exhaled port may help prevent aerosolization.
Caution is advised with use of Evita ventilators and Hamilton
G series ventilators
Adjunctive Therapy
In patients with refractory hypoxemia the following adjunctive
therapies may be considered. However, it should be recognized
that most of these therapies are restricted to tertiary
centers and are of unproven benefit.
- Inhaled nitiric oxide
- Inhaled prostaglandin (see appendix for protocol)
- Prone positioning
- ECMO
There is some evidence to adopt a fluid restrictive strategy
(FACT trial). Paralytics should be used sparingly. Sedation
and analgesic requirements may be extreme. High dose requirements
have been reported. In this instance consider adding adjunctive
agents to augment sedation. At present there is no data
to support the use of steroids, immunoglobulin, interferons,
surfactant, or activated protein C outside the confines
of a clinical trial.
Hospital / Ventilator Associated Pneumonia
A bacterial super-infection or failure of antiviral therapy
should be considered in a patient who remains febrile or
who develops evidence of a new respiratory tract infection.
We recommend that a deep nasopharyngeal swab (NP) AND endotracheal
aspirate (ETA)/ bronchoaveolar lavage (BAL) specimens be
sent for viral and bacteriologic evaluation. A recent
MMRW report supports the notion of bacterial
super-infection in patients with H1N1. However, the role
of super-infection on patient outcome was not demonstrated,
we recommend initial broad spectrum antibiotic coverage
for suspected bacterial super-infection and then tailoring
of antibiotics based on culture results.
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