Teaching Points:
- Influenza presents year-round but with a predominantly seasonal distribution. It is a highly transmissible virus with droplet (and possibly airborne particle) spread. Patients present with fever, malaise, lassitude, cough, myalgias, arthralgias and headache. The illness is usually self-limiting lasting approximately 1 week.
- Patients with underlying cardiac disease, respiratory disease, diabetes, or immunosuppression are at high risk of developing severe disease. Pregnant women, in the third trimester are also at risk compared to age-matched controls.
- Vaccines have been shown to have mortality and morbidity benefit, particularly amongst high risk groups. But vaccination of healthy individuals is proposed to have indirect benefit to these high-risk groups as well.
- A study done here in Toronto has shown that admitted patients with influenza, particularly those who are critically ill should be treated with oseltamivir. There is a reduction in mortality.
- Other notable sequelae:
- Primary viral pneumonia or bacterial superinfection -- Most commonly streptococcus pneumoniae or staphylococcus aureus (including community acquired MRSA). This can be severe.
- Viral myocarditis (rare)
- myositis with possible rhabdomyolysis
- Guillain-Barre syndrome, Influenza meningoencephalitis, Transverse myelitis
- Primary viral pneumonia or bacterial superinfection -- Most commonly streptococcus pneumoniae or staphylococcus aureus (including community acquired MRSA). This can be severe.
In this case, the patient likely had a secondary bacterial infection with lobar pneumonia, sepsis and eventually multiorgan failure. Early recognition and treatment of sepsis is important. The principle is called "Early Goal Directed Therapy". This is a protocol of interventions designed to maximize tissue perfusion and interventions in a rational way.
Essentially this means:
- IV crystalloids to maintain central venous pressure of 8-12 (JVP 3-7cm is about that if you don't have a CVP line), normal blood pressure (MAP >=65) and mixed venous oxygen saturation of >=70%
- If still not at goal with crystalloids add vasopressors (i.e. norepinephrine)
- If still not at goal with this and hematocrit <30%,>
- If still not at goal with this, add positive inotrope dobutamine.
- Early appropriate antibiotic therapy
- Source control -- removal of septic focus, drainage of pus, etc --> this is often the neglected step....
- NB: pentastarch may be harmful and so I don't use it. The use of albumin is also contraversial -- an ongoing clinical trial hopes to solve this.
Notable people affected by the 1918 pandemic:
- Woodrow Wilson -- allegedly had meningoencephalitis while signing the treaty of Versailles
- Harvey Cushing -- developed Guillain-Barre post-influenza
- William Osler -- died of empyema (post influenza superinfection)
No comments:
Post a Comment