Infection Prevention Challenges in the Medical Intensive Care Unit (MICU)

Patients admitted to the Medical Intensive Care Unit (MICU) have a myriad of comorbidities and conditions. In spite of the variety, they all have diseases that predispose them to many days in the Intensive Care Unit (ICU). Prolonged ICU stays increase the chances the patient will require a ventilator, potentially developed ventilator-associated pneumonia and/or need a tracheostomy. Illnesses such as sepsis, renal failure, liver disease, and cancer-related complications increase the need for multiple antibiotics and the placement of central venous access, arterial lines, and dialysis catheters. These patients are often immunocompromised and at higher risk for infections. Since the pandemic began, MICUs across the country have become the primary location to house patients with COVID-19 infection. The number of patients with hypoxemic respiratory failure and adult-respiratory distress syndrome (ARDS) caused by this virus climbed sharply. Nationwide, the number of ARDS patients in the ICU at one time was more than a previous year’s worth of cases combined. These patients, if they survive, require prolong mechanical ventilation (MV) with protracted hospital stays. Because of immunosuppression with steroids and other immune-modulators, they are at much higher risk for secondary and opportunist infections including ventilator-associated pneumonia (VAP). In our MICU, the time on ventilator grew from an average of 3.08 days to more than 14 days [unpublished data from Memorial Herman Hospital-TMC] and the number of tracheostomies required in our MICU increased 500% in the 2 years from March 2020 to March 2022 (the time of writing this chapter). Patients with tracheostomies and mechanical ventilation warrant preventative strategies against VAP and other complication. Additionally, the number of COVID-19 patients needing extracorporeal membrane oxygenation (ECMO) support skyrocketed. These patients require extended ECMO runs, previously the average time was 2 weeks, but now has extended to 3–6 months, or sometimes longer. Patients are on mechanical ventilation for the majority of time they are on ECMO which eventually necessitates a tracheostomy. Despite the growing number of patients on ECMO since the beginning or the pandemic, there are currently no adequate guideline recommendations on how to prevent infections in the ECMO population. Because MICU patients have more comorbidities which increase their risk for gastrointestinal bleeding, stress ulcer prophylaxis poses a unique challenge. We will review the use of proton pump inhibitors (PPIs) in the ICU and how they convey a risk of infection.