Relaxing the Protected Environment Has Not Adversely Impacted Early Outcome of Older Patients (≥ 50 years) with AML and HR- MDS Receiving Induction Therapy
Authors: Mattiuzzi Gloria , Greenberg Edythe , Pierce Sherry , Cortes Jorge , Freireich Emil , O’Brien Susan , Kantarjian Hagop 
Published: April 2020

Background: As part of our standard of care, patients (pts) with acute myelogenous leukemia (AML) and high risk myelodysplastic syndrome (HR-MDS) older than 50 years undergoing induction remission therapy (IC) are offered to be admitted to rooms in the “Protected Environment” (PE) unit during their therapy. The objective of this measure is to decrease the incidence of infections. Since Nov 2007 several changes were made to the PE rooms due to construction at our institution:

Old PE unit (OPE) New PE unit (NPE) Use of shoe covers Shoe covers should be used at the entrance of the unit and should be kept on until leaving the unit. Shoe covers should be used upon entrance to the unit and changed when entering each room. Visitations Visitors are not allowed in the room. Visitors use a separate room for visitation. Visitors are allowed inside the room and must use gown, gloves and mask. Water filtration Water supply for OPE was independent from main hospital water supply. Special filtration x3 was plumbed into the unit. The ice machine was plumbed with filtered water. Water from main hospital lines. Ice machine/water from main hospital lines and plumbed with a filtration system. Window Blinds Single blind built inside the windows with an electronic switch for patient operation. Double shades inside the room operated by the patient.

Both units (OPE and NPE) continue with the same HEPA filtration system with air exchanged 15 times per hour.

Objective: To evaluate the impact of these changes in the incidence of infections and mortality of pts admitted to the NPE.

Methods: Admission to the NPE became effective Nov 2007. We retrospectively reviewed medical records of pts who were admitted to the OPE from May 2007 to October 2007 and compared to the pts who were admitted to the NPE from Nov 2007 to May 2008.

Results: 42 patients were admitted to the OPE, and 32 to the NPE. No differences were found in baseline characteristics between the 2 groups. The majority had AML [OPE=90% and NPE=84%, p=0.430] and Zubrod performance status ≥ 2 [83% and 91 %, OPE and NPE respectively, p= 0.363]. Median age was 64 yo (r: 31–89) for OPE pts and 60 (r: 18–79) for NPE. Ninety-five percent of the pts in OPE and 97% of the pts in the NPE received chemotherapy with cytarabine containing regimens; 43% and 47% of the pts had ANC &lt;500 at start of IC (p=0.734). All pts received antifungal and antibacterial prophylaxis. There were no differences in the incidence or type of infections between the 2 groups (Table 1).

OPE N= 42 NPE N= 32 No. pts infected, (%) 35 (83) 26 (81) No. infectious episodes 42 32 Type of infections, (%) Bacteremia 8 (19) 3 (9) Pneumonia 8 (19) 7 (22) FUO 23 (55) 17 (53) Others 3 (7) 5 (16) Organisms isolated, n (%) Bacteria 11 (26) 7 (22) Fungi 1 (2) 1 (3) Virus 0 1 (2) Clinically documented infections (%) 30 (71) 23 (72)

At 4 weeks there was no difference in mortality between the two groups (1/42 and 0/32 for OPE and NPE, respectively, p=0.379).

Conclusions: Although the NPE is less restrictive in protective measures against infections, it provides similar protection compared to the OPE. Induction remission mortality has not been adversely affected.