Ventilator-associated tracheobronchitis

Health Care, Medicine, Social Health Community 372 Comments

Ventilator-associated tracheobronchitis (VAT) has the same clinical implications as ventilator-associated pneumonia (VAP). An observational study of 28 patients with VAT and 83 patients with VAP [1] showed that VAT groups had a similar length of intensive care unit stay, length of hospital stay, duration of mechanical ventilation, survival rate to discharge, need for tracheostomy, and need for antibiotics.

Ventilator induced diaphragmatic atrophy

Controlled mechanical ventilation can lead to a very rapid type of disuse atrophy involving the diaphragmatic muscle fibers. An observational study found that diaphragmatic strength decreased progressively during mechanical ventilation and that long-term (>24 hours) mechanical ventilation was associated with diaphragmatic muscle injury, atrophy, and proteolysis compared to short-term mechanical ventilation (2-3 hours).(2)

Starting enteral nutrition in a patient on ventilator

Starting enteral nutrition with a low infusion rate improves tolerability, compared to initiation at the target rate. A randomized study of 200 mechanically ventilated patients showed that enteral feeding ( at the target rate or at 10 mL/hr for six days before being incrementally increased to the target rate) showed no differences in mortality, ventilator-free days, or ICU-free days, but the group that began at the target rate had more episodes of elevated gastric residual volumes and a trend toward more diarrhea. (3)

References
1. Dallas J, Skrupky L, Abebe N, et al. Ventilator-associated tracheobronchitis in a mixed surgical and medical ICU population. Chest 2011;139:513-8.
2. Jaber S, Petrof BJ, Jung B, et al. Rapidly progressive diaphragmatic weakness and injury during mechanical ventilation in humans. Am J Respir Crit Care Med 2011;183:364-71.
3. Rice TW, Mogan S, Hays MA, et al. Randomized trial of initial trophic versus full-energy enteral nutrition in mechanically ventilated patients with acute respiratory failure. Crit Care Med 2011;39:967-74.

Hepatitis B Vaccination update

Health Care, Medicine 556 Comments

• The regimen for the vaccine is three doses at one and six months apart.

• Longer than recommended intervals between doses do not reduce final antibody concentrations, although protection might not be attained until the recommended number of doses has been administered.(1-5)

• A positive immune response to the vaccine is defined as the development of hepatitis B surface antibody (anti-HBs) at a titer of >10 mIU/mL.

• An interruption in the vaccine schedule does not require restarting the entire series of vaccination or adding extra doses.(6,7)

• If the vaccination schedule is interrupted after the first dose, the second dose should be administered as soon as possible.(8)

• The second and third doses should be separated by an interval of at least two months.

• If only the third dose is delayed, it should be administered when convenient.

• Protective anti-HBs titers may be attained in some after only one or two doses of vaccine, completion of the full course (three doses) is recommended to maximize the anti-HBs titer and duration of protection.

• Anti-HBs titers decrease with time but the duration of protection is long (15 -22 years after the primary vaccination schedule).(9-13) Routine booster injections are not required.(14,15)

• Patients with serologic markers of past HBV infection (anti-HBc and anti-HBs positive) do not need HBV vaccination even if they have low titers of anti-HBs.

• Vaccines should be given intramuscularly since deposition of the vaccine into adipose tissue result in a lower seroconversion rate.(16)

• Deltoid is the preferred site in adults for vaccination.

• Longer needles should be used in overweight individuals.

• Hepatitis B vaccine is effective not only in preventing HBV infection but also in preventing the sequelae of chronic HBV infection.

• It is the first example that cancer can be prevented by vaccination.

References

1. Wiström J, Ahlm C, Lundberg S, et al. Booster vaccination with recombinant hepatitis B vaccine four years after priming with one single dose. Vaccine 1999;17:2162.

2. Zechowy R, Rubin LG. Effect of the time interval between the first and second doses of hepatitis B vaccine on the antibody titer achieved after the third dose. Child Hos Q 1997;9:67.

3. Middleman AB, Kozinetz CA, Robertson LM, et al. The effect of late doses on the achievement of seroprotection and antibody titer levels with hepatitis b immunization among adolescents. Pediatrics 2001;107:1065.

4. Halsey NA, Moulton LH, O’Donovan JC, et al. Hepatitis B vaccine administered to children and adolescents at yearly intervals. Pediatrics 1999;103:1243.

5. Heron LG, Chant KG, Jalaludin BB. A novel hepatitis B vaccination regimen for adolescents: two doses 12 months apart. Vaccine 2002;20:3472.

6. Saito K. Introductory remark of Dr. Rokuzo Kobayashi’s achievements. Keio J Med 2002;51 Suppl 2:2.

7. Hepatitis B vaccine: What you need to know. Available at: www.cdc.gov/vaccines/pubs/vis/downloads/vis-hep-b.pdf (Accessed on October 20, 2009).

8. Hoofnagle JH. Toward universal vaccination against hepatitis B virus. N Engl J Med 1989;321:1333.

9. Liao SS, Li RC, Li H, et al. Long-term efficacy of plasma-derived hepatitis B vaccine: a 15-year follow-up study among Chinese children. Vaccine 1999;17:2661.

10. Lin HH, Wang LY, Hu CT, et al. Decline of hepatitis B carrier rate in vaccinated and unvaccinated subjects: sixteen years after newborn vaccination program in Taiwan. J Med Virol 2003;69:471.

11. Yuen MF, Lim WL, Chan AO, et al. 18-year follow-up study of a prospective randomized trial of hepatitis B vaccinations without booster doses in children. Clin Gastroenterol Hepatol 2004;2:941.

12. McMahon BJ, Bruden DL, Petersen KM, et al. Antibody levels and protection after hepatitis B vaccination: results of a 15-year follow-up. Ann Intern Med 2005;142:333.

13. Zanetti AR, Mariano A, Romanò L, et al. Long-term immunogenicity of hepatitis B vaccination and policy for booster: an Italian multicentre study. Lancet 2005; 366:1379.

14. Lu CY, Chiang BL, Chi WK, et al. Waning immunity to plasma-derived hepatitis B vaccine and the need for boosters 15 years after neonatal vaccination. Hepatology 2004;40:1415.

15. Jan CF, Huang KC, Chien YC, et al. Determination of immune memory to hepatitis B vaccination through early booster response in college students. Hepatology 2010;51:1547.

16. Shaw FE Jr, Guess HA, Roets JM, et al. Effect of anatomic injection site, age and smoking on the immune response to hepatitis B vaccination. Vaccine 1989;7:425.