Treatment options in a mechanically ventilated young patient Mechanically ventilated young patient who develops pneumonia A 23-year-old male motorcycle passenger was involved in a road accident. He was not wearing a helmet. The patient has a closed head injury with multiple facial fractures and is intubated on admission to hospital. Learning's: © Academy Of Infection Management 2015 (All Rights Reserved) Treatment options in a mechanically ventilated young patient

History and examination A 23-year-old male motorcycle passenger was involved in a road accident. He was not wearing a helmet. The patient has a closed head injury with multiple facial fractures and is intubated on admission to hospital. © Academy Of Infection Management 2015 (All Rights Reserved)

Questions 1 & 2 What would be your next course of action and why? Would you administer prophylactic antibiotics? Please specify your reasons. © Academy Of Infection Management 2015 (All Rights Reserved)

Treatment The oromaxillary facial surgeon administers cefazolin as anti-bacterial prophylaxis. © Academy Of Infection Management 2015 (All Rights Reserved)

Question 3 Do you agree with the surgeon’s choice of cefazolin as prophylactic antibiotic? Please give reasons for your answer. © Academy Of Infection Management 2015 (All Rights Reserved)

OUTCOME On Day 4 of cefazolin therapy, the patient develops a fever (38.4°C) together with: Increased serum creatinine correlating with a reduced creatinine clearance (~30 mL/min), which could be due to exposure to contrast media or trauma A slight increase in sputum production (12 300/μL) with no increase in bands (ie no left shift) a slightly elevated white blood cell (WBC) count of 12.3 x 109/L A chest X-ray is taken to determine whether the patient has an infection, fluid overload or contusion. The chest X-ray reveals pneumonia. © Academy Of Infection Management 2015 (All Rights Reserved)

Question 4 What are the most important factors to consider in the management of infections such as this? Why are these factors important? Leibovici et al. J Intern Med 1998;244:379–386 Vincent. Lancet 2003;361:2068–2077 © Academy Of Infection Management 2015 (All Rights Reserved)

Question 5 Would you change or modify the patient’s antibiotic regimen? Please specify reasons for your decision. Rello et al. Chest 2001;120:955–970 © Academy Of Infection Management 2015 (All Rights Reserved)

Question 6 If you decide to change or modify therapy, what empiric therapy would you choose and why? © Academy Of Infection Management 2015 (All Rights Reserved)

Question 7 What are the most important organisms for which antibiotic coverage should be provided and why? Are these organisms prone to developing resistance on therapy? Cosgrove et al. Arch Intern Med 2002;162:185–190 Kollef. Chest 1999;115:8–11 © Academy Of Infection Management 2015 (All Rights Reserved)

Question 8 What pharmacokinetic/pharmacodynamic parameters do you think should be considered when making treatment decisions? Drusano et al. Clin Microbiol Infect 1998;4(Suppl. 2):S27–S41 Drusano & Craig. J Chemother 1997;9:38–44 © Academy Of Infection Management 2015 (All Rights Reserved)

Clinical Course On Day 4, ceftriaxone is added to the patient’s antibiotic regimen. Cefazolin therapy is continued The patient’s condition is stable on Days 5–13 On Day 14, ceftriaxone and cefazolin are discontinued On Day 18, a chest X-ray reveals a possible new infiltrate A temperature spike occurred during the previous night — the morning WBC count is 18.5 x 109/L (18 500/μL) — there is a change in the quality and consistency of the patient’s sputum. © Academy Of Infection Management 2015 (All Rights Reserved)

Question 9 Do you agree with the decision to add ceftriaxone to the patient’s antibiotic regimen? Explain the reasons for your answer. © Academy Of Infection Management 2015 (All Rights Reserved)

Question 10 At this point, would you administer a cephalosporin or another class of antibiotic? Give reasons for your decision. © Academy Of Infection Management 2015 (All Rights Reserved)

Clinical Course (continued) Ceftazidime is administered Enterobacter spp. are reported on Day 20 Clinical deterioration (fever, increased WBC count, worsening infiltrates on chest X-ray and a change in ventilation requirements) is reported on Day 22 Ceftazidime is discontinued and therapy is started with an aminoglycoside and piperacillin–tazobactam. © Academy Of Infection Management 2015 (All Rights Reserved)

Question 11 Do you agree with the change in antibiotic therapy? Give reasons for your answer. © Academy Of Infection Management 2015 (All Rights Reserved)

Clinical Course (continued) On Day 25, the patient’s condition stabilises and the Enterobacter spp. are reported to be resistant to ceftazidime Between Days 26 and 36, the patient’s pneumonia resolves; he completes the 14-day course of combination therapy. © Academy Of Infection Management 2015 (All Rights Reserved)

Question 12 What are the potential clinical and economic implications of drug- resistant bacterial pneumonia? Abramson. Infect Control Hosp Epidemiol 1999;20:408–411 Carmeli et al. Arch Intern Med 1999;159:1127–1132 Cosgrove et al. Arch Intern Med 2002;162:185–190 Stosor et al. Arch Intern Med 1998;158:522–527 © Academy Of Infection Management 2015 (All Rights Reserved)

Additional Questions What are the key learning points from this case? Which of the AIM core principles could be applied to this case? How could the educational value of this case be improved? © Academy Of Infection Management 2015 (All Rights Reserved)

What if ... P. aeruginosa was the documented pathogen? P. aeruginosa culture persisted? The antibiotic dose was incorrect? The patient suffered from renal failure?