Pandemic H1 N1 Influenza

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Pandemic H1 N1 Influenza

  1. 1. Pandemic 2009 H1N1 Influenza<br />PeteyLaohaburanakit, MD, FCCP<br />Intensive Care Unit<br />Rogue Valley Medical Center<br />October 8, 2009<br />
  2. 2. Outline<br />Introduction<br />Global experiences with 2009 H1N1<br />Southern hemisphere<br />Published cohorts<br />Hospital management<br />Case identification<br />Infection control and prevention<br />Treatment<br />Disaster preparedness, triage, and allocation of scarce resources<br />
  3. 3. 2009 H1N1 Influenza A<br />Quadruple re-assortment of RNAs from two swine strains, one human strain and one avian strain<br />First recognized in March-April 2009 in Mexico<br />Phase 6 pandemic status by June 2009<br />Currently named 2009 H1N1 Influenza by CDC<br />
  4. 4. 2009 H1N1 Influenza A<br />1976 – present<br />2009 H1N1<br />
  5. 5. The Big Deal<br />Novel virus to humans<br />Sustained human-to-human transmission<br />Causes severe, fatal illnesses in unusual populations<br />May re-assort with seasonal flu (H3N2) or avian flu (H5N1)<br />Unknown interactions with seasonal flu<br />
  6. 6. Risk Groups for Seasonal Flu<br />Chronic lung disease<br />Cardiac disease<br />Immunosuppression<br />Diabetes mellitus<br />Chronic kidney disease<br />
  7. 7. Risk Groups for 2009 H1N1<br />Same as seasonal flu risk groups PLUS<br />Pregnancy*<br />Obesity*<br />Age 6 months to 24 years old*<br />Highest illness rates<br />Second highest mortality rates<br />Age 25 to 64 years old*<br />Highest mortality rates<br />
  8. 8. Is the mortality rate higher than seasonal flu?<br />Study from Australia and New Zealand<br />NEJM 2009 October<br />
  9. 9.
  10. 10. Experiences with 2009 H1N1<br />Data from Southern hemisphere<br />Published cohorts<br />Mexico city<br />Spain<br />Michigan<br />Local experience at RVMC<br />
  11. 11. 2009 H1N1 in Southern Hemisphere<br />Reports from Argentina, Australia, Chile, New Zealand, and Uruguay<br />Viral strain similar to the U.S. strain<br />Similar at-risk groups<br />Highest mortality in adults 25-64 years of age<br />47-60% with known risk factors for severe disease<br />Increased risks of complications in pregnant women<br />Assessment of 2009 Influenza A (H1N1) Pandemic on Selected Countries in the Southern Hemisphere. Department of Health and Human Services. August 26, 2009.<br />
  12. 12. 2009 H1N1 in Southern Hemisphere<br />About 6-7 week ascent to peak followed by rapid decline<br />Community mitigation measures<br />School closures<br />Cancellation of mass gatherings<br />Isolation, quarantine, other social distancing<br />Healthcare systems experienced stress<br />Geographically isolated<br />Relatively short-lived<br />
  13. 13. Good news or Bad news?<br />During Spring/Summer, hospitalization rates in the U.S. is 2.6 per 100,000 population (as opposed to 7.8 to 21.7 for the Southern hemisphere).<br />Schools open in the fall.<br />Our flu season officially starts October 4th 2009.<br />
  14. 14. Second Waves<br />Miller MA et al. New England J Med <br />2009 ; 360:2595-2598.<br />USUAL INFLUENZA SEASON<br />DEATHS<br />
  15. 15. Mexico City<br />488 with influenza-like illness (ILI)<br />114 confirmed by PCR<br />22 observed in ER<br />33 hospitalized for more than 24 hours.<br />13 (39.3%) required non-invasive ventilation.<br />9 (27%) required mechanical ventilation; average time on MV was 7 days (range 1-25 days).<br />Data courtesy of Dr. Guillermo <br />Dominguez-Cherit<br />
  16. 16. Mexico City<br />
  17. 17. Mexico City<br />
  18. 18. Mexico City<br />
  19. 19. Mexico City<br />
  20. 20. Mexico City<br />
  21. 21. Mexico City<br />* Some patients required both non-invasive and invasive ventilation.<br />
  22. 22. Mexico City<br />
  23. 23. Mexico City<br />
  24. 24. Spain<br />Rello J, et al. Crit Care 2009;13:R148.<br />
  25. 25. Spain<br />
  26. 26. Spain<br />
  27. 27. Spain<br />
  28. 28. Spain<br />
  29. 29. Michigan<br />Intensive Care Patients With Severe Novel <br />Influenza (H1N1) Virus Infection – Michigan<br />MMWR. June 2009<br />
  30. 30. Michigan<br />
  31. 31. RVMC – All cases<br />Fourteen cases of confirmed H1N1 (as of October 6)<br />Average age 17 years (range 35 days-42 years)<br />Male : Female = 1.2:1<br />Average hospital length of stay 6.5 days<br />Excluding ICU patients, hospital LOS 2 days<br />Two patients expired. <br />
  32. 32. RVMC – ICU cases<br />4 admitted to ICU<br />Age 25-34 years old<br />3/4 developed severe ARDS.<br />All ARDS patients required high-frequency oscillator.<br />Two deaths, one transferred to a long-term acute care facility on mechanical ventilation, one discharged from hospital after 3 days<br />Average hospital/ICU LOS is 16 days (range 3-52 days)<br />
  33. 33. RVMC – ICU Cases<br />
  34. 34. Common Themes<br />Severe disease found in younger patients (pooled mean is 40 years old).<br />The majority of ICU admits required prolonged invasive mechanical ventilation.<br />Non-invasive ventilation not effective.<br />Significant portion required HFOV or ECMO. <br />
  35. 35. Common Themes<br />Spain and Michigan reported range of 4-8 days from onset to first antiviral dose. <br />ICU mortality rates varied from 28 to 45% (Mexico City, Spain, and Michigan).<br />
  36. 36.
  37. 37. Hospital Management<br />Case identification<br />Clinical diagnosis<br />Laboratory confirmation<br />Infection control and Prevention<br />Treatment of suspected cases<br />Disaster preparedness, triage, and allocation of scarce resources<br />
  38. 38. Case Identification<br />Symptoms and signs<br />Fever<br />Cough<br />Malaise<br />Myalgias<br />Diarrhea and vomiting*<br />Laboratory findings<br />Leucopenia or lymphopenia<br />Elevated serum lactate dehydrogenase (LD)<br />
  39. 39. Case Identification<br />Laboratory confirmation<br />Priority groups<br />Those require hospitalization<br />Those at risk of developing complications<br />Samples<br />Nasopharyngeal swabs or aspirate<br />Nasal swab plus throat swab<br />Nasal wash<br />Tracheal aspirate<br />
  40. 40. Sampling<br />Use personal protective equipment while swabbing.<br />Swab horizontally, away from nasal septum.<br />Samples need to be placed in viral transport media and placed on ice or cold packs or at 4 ºC for transport.<br />
  41. 41. Diagnostic Tests<br />Rapid antigen detection<br />Immunofluorescence<br />Nucleic acid testing : rRT-PCR<br />Viral culture<br />Antibody testing<br />Acute sample<br />Convalescent sample<br />
  42. 42. Diagnostic Tests<br />Beigel JH. Crit Care Med 2008;36:2660-2666.<br />
  43. 43. Diagnostic Tests<br />Recommendation<br />Send two swabs in one viral transport media for both rapid antigen detection and rRT-PCR for 2009 H1N1<br />If 2009 H1N1 continues to predominate<br />Positive rapid antigen leads to treatment with Oseltamivir or Zanamivir<br />If seasonal flu becomes co-dominant with 2009 H1N1<br />Positive rapid antigen may indicate combination treatment with Oseltamivir and Amantadine OR Zanamivir as single agent<br />Negative rapid antigen test does not exclude influenza infection!<br />
  44. 44.
  45. 45. Infection Control and Prevention<br />Droplet and standard precautions<br />Surgical mask<br />Eye protection<br />Gloves<br />Close contact is &lt; 6 feet<br />CDC recommends isolation until symptoms resolved or &gt; 7 days after onset, whichever is longer.<br />RVMC recommends isolation until hospital discharge.<br />
  46. 46. Infection Control and Prevention<br />Fit-tested N95 masks for aerosol generating procedureslisted in the WHO infection control recommendations<br />Aspiration of respiratory tract<br />Intubation<br />Resuscitation<br />Bronchoscopy<br />Autopsy<br />
  47. 47. Infection Control and Prevention<br />Hand hygiene<br />Cough etiquette<br />Self-quarantine and social distancing<br />Vaccination<br />
  48. 48. Why personal hygiene is important<br />
  49. 49. Infection Control and Prevention<br />N95 masks? - Pros<br />McIntyre R et al. (unpublished data)<br />1936 healthcare workers in China<br />Randomized to surgical masks or N95<br />N95 group had 75% reduction in influenza-like illness, 75% reduction in confirmed influenza<br />Surgical mask had no efficacy<br />Other details unavailable <br />What’s the control group?<br />Usage and compliance?<br />Other preventive measures?<br />
  50. 50. Infection Control and Prevention<br />N95 masks? - Cons<br />Loeb M et al. JAMA 2009;302(17):e-pub ahead of print Oct 1, 2009.<br />446 nurses in 8 Ontario hospitals<br />Randomized to either surgical masks or fit-tested N-95 masks<br />23.6% of surgical masks group and 22.9% of N-95 group developed laboratory confirmed influenza<br />
  51. 51. Infection Control and Prevention<br />Problems with N95<br />Evidence to support the use is not very strong.<br />Inadequate supply, especially in outpatient settings<br />Requires fit testing<br />Not practical for prolonged, day-to-day use<br />Uncomfortable<br />Costly<br />Difficult to maintain compliance<br />
  52. 52. What should we do?<br />CDC, AMA, and IOM recommend the use of fit-tested N95.<br />IDSA, APIC and SHEA recommend surgical masks.<br />RVMC Infection Control recommends<br />Droplet/contact precautions plus eye protection<br />N95 for aerosol-generating procedures<br />
  53. 53.
  54. 54. Treatment<br />Supportive care<br />Isolation<br />Oxygen therapy<br />Intravenous hydration<br />Symptomatic relief<br />Critical care needs : ventilator, hemodynamic support, etc.<br />Antiviral therapy<br />Adjunct therapies – Not generally recommended<br />Prophylactic antibiotics<br />Steroid<br />
  55. 55. Antiviral Therapy<br />2009 H1N1 is resistant to Amantadine and Rimantadine.<br />Susceptible to neuraminidase inhibitors<br />Oseltamivir<br />Zanamivir<br />
  56. 56. Antiviral Therapy<br />Benefits of antiviral therapy<br />Shortens the duration of symptoms<br />Decreases the risks of complicated disease<br />Decreases viral shedding<br />Timing<br />Best results if initiated &lt; 48 hours after onset<br />May still help after 48 hours if symptoms are severe or in pregnant patients<br />
  57. 57. Oseltamivir<br />Oral formulation<br />Dosage<br />75 mg po bid for 5 days<br />150 mg po bid for 10 days for the critically ill<br />Side effects/practical issues<br />Neuropsychiatric side effects<br />Oseltamivir resistance<br />Poor GI absorption<br />
  58. 58. Zanamivir<br />Inhalation via Diskhaler®<br />Report of intravenous use (unlabeled)<br />Kidd IM et al. Lancet 2009;374;1036.<br />Dosage<br />Two inhalations (10 mg total) twice a day for 5 days<br />Side effects/practical issues<br />Headache<br />Cough and bronchospasm<br />Not appropriate in children &lt; 7 years old<br />Not administrable via ventilator circuit<br />
  59. 59. Oseltamivir resistance<br />Risk factors<br />Prior exposure to Oseltamivir (prophylaxis or treatment)<br />Immunocompromised patients<br />Treatment options in suspected resistance<br />Zanamivir when appropriate<br />Oseltamivir plus Rimantadine or Amantadine<br />Oseltamivir, Rimantadine plus Ribavirin<br />
  60. 60. Antiviral Prophylaxis<br />CDC guidance – September 22, 2009<br />Close contact in high risks of complications<br />Close unprotected contact in healthcare workers, first responders<br />An alternative is to treat early if symptoms occur after a suspected exposure.<br />
  61. 61. Secondary Bacterial Infection<br />Retrospective pathologic review suggested secondary bacterial infection was a common cause of death in Pandemic H1N1 in 1918.<br />Occurs several days after onset.<br />Staphylococcus aureusincluding MRSA<br />Necrotizing pneumonia<br />Pneumatocele<br />Gram negative bacteria<br />
  62. 62. Influenza-like Illness<br />Need for hospital admission<br />Risk factors for complicated disease<br /><ul><li>Isolation/self quarantine
  63. 63. Send samples for rRT-PCR ± Rapid antigen
  64. 64. Start empiric antiviral treatment</li></ul>Supportive care ± follow up<br />
  65. 65. Influenza-like Illness<br />Need for hospital admission<br />Risk factors for complicated disease<br /><ul><li>Isolation/self quarantine
  66. 66. Send samples for rRT-PCR ± Rapid antigen
  67. 67. Start empiric antiviral treatment</li></ul>High risks for disease acquisition/spread<br />Consider antiviral treatment<br />Supportive care ± follow up<br />
  68. 68.
  69. 69. Disaster Preparedness, Triage and Allocation of Resources<br />At a given time, most hospitals operate at over 90% capacity.<br />Does not take much to overwhelm healthcare resources.<br />Hospitals, practitioners, hospital staff need to prepare for a surge in patient load.<br />
  70. 70. What NOT to do<br />
  71. 71. Disaster Preparedness<br />Be prepared<br />“Know your enemies and know yourself, you will be victorious a hundred times in a hundred battles…”<br />Sun Tzu’s The Art of War<br />
  72. 72. Disaster Preparedness<br />Educate yourself<br />CDC guidance<br />Flu.gov or Flu.oregon.gov<br />American Medical Association<br />Society of Critical Care Medicine<br />New England Journal of Medicine H1N1 Center<br />
  73. 73. Disaster Preparedness<br />Protect yourself<br />Personal hygiene<br />Vaccination<br />Protective equipments<br />Self quarantine<br />Social distancing if needed<br />
  74. 74. Disaster Preparedness<br />Maximize staffing<br />Tiered staffing model<br />Physicians, mid-level practitioners, RNs, RTs, and pharmacists<br />Maximize hospital facility<br />Outpatient surgery, short stay unit<br />Cafeteria<br />Auditorium<br />Alternate care site (ACS)<br />
  75. 75. Tiered Staffing<br />
  76. 76. Definition of Triage<br />“Scarce resources are used to provide the maximum benefit to the population at large, even if it means that other victims who might have been saved under usual circumstances cannot be treated optimally…”<br />Christian M et al. Critical care during a pandemic: report from Ontario Health Plan for an influenza pandemic (OHPIP) working group on admission/discharge triage. 2006<br />
  77. 77. Triage<br />Every practitioner performs triage every single day, knowingly or unknowingly.<br />Prioritization of patients with semi-objective risk calculation or eyeballing<br />When resources are available, trials of treatment are reasonable.<br />When resources are limited, trial of treatment may exhaust extensive resources and cause others to die.<br />
  78. 78. The Scenario<br />One ventilator<br />Three H1N1 patients<br />34-year-old single mother of 2<br />82-year-old man who is a big donor to hospital foundation with severe emphysema and depends on home oxygen<br />18-year-old male with drug abuse history<br />How do we decide who gets the ventilator?<br />
  79. 79. Ethical Principles in Triage<br />Responsibility toward<br />the common good<br />Individual needs<br />Available resources<br />
  80. 80. Response Thresholds<br />Christian M et al. Critical care during a pandemic: report from OHPIP working group on admission/discharge triage. 2006<br />
  81. 81. Opportunities for Triage<br />
  82. 82. Mortality Prediction for Triage<br />Objective<br />Reliable<br />Valid<br />Sequential organ failure assessment (SOFA) score<br />Christian MD et al. Development of a triage protocol for critical care during an influenza pandemic. CMAJ 2006; 175:1377-1381.<br />
  83. 83. SOFA Score<br />
  84. 84. Modified SOFA Score<br />
  85. 85. Utah Hospitals and Health Systems Association. Utah Pandemic Influenza Hospital and ICU Triage Guidelines. January 10, 2009.<br />
  86. 86. Exclusion Criteria for Admission<br />Utah Hospitals and Health Systems Association. Utah Pandemic Influenza Hospital and ICU Triage Guidelines. January 10, 2009.<br />
  87. 87. The Scenario<br />One ventilator<br />Three H1N1 patients<br />34-year-old single mother of 2<br />82-year-old man who is a big donor to hospital foundation with severe emphysema and depends on home oxygen<br />18-year-old male with drug abuse history<br />How do we decide who gets the ventilator?<br />
  88. 88. Who Gets the ICU Bed and Ventilator?<br />
  89. 89. Multi-modality Model<br />White DB et al. Ann Intern Med 2009;150:132-138.<br />
  90. 90. Palliative Care Services<br />Those triaged to non-critical care must be treated nonetheless.<br />Simple treatment measures may be provided if resources are available (e.g. oxygen, medications).<br />Patients should be ensured adequate symptom relief and palliative care expertise.<br />
  91. 91. Take Home Messages<br />Recognize high-risk groups for severe 2009 H1N1 disease<br />Most hospitalized patients are younger and could become critically ill quickly.<br />High index of suspicion<br />Isolate early and sufficiently.<br />Protect yourself and your patients.<br />
  92. 92. Take Home Messages<br />Treat early and adequately<br />Treatment most effective within 48 hours<br />Treatment beyond 48 hours warranted in pregnancy and those with persistent, severe symptoms<br />Double dose, double duration for severe cases<br />Be informed, educated and prepared.<br />

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