Outcomes of Regimented Weight Monitoring on Morbidity and Mortality during AML Induction

Acute myeloid leukemia (AML) is characterized by the clonal expansion of myeloid blasts in the peripheral blood, bone marrow and other tissues. AML is a disease of elderly, with median age of 67 years at diagnosis. Current therapeutic options for elderly individuals with AML include intensive chemotherapy with a cytarabine and anthracycline backbone, hypomethylating agents (decitabine and azacytidine) alone or in combination with venetoclax. Targeted therapies, low dose cytarabine, investigational agents and supportive care with hydroxyurea and transfusions are other options.

While monitoring daily weights has been well documented in APL due to concern for differentiation syndrome, little has been documented in AML. Monitoring daily weights can be a useful tool in maintaining patients' euvolemic status. This can help in appropriately resuscitating patients with AML as they are prone to sepsis due to their immunocompromised status. Also, it can help prevent fluid overload and prevent hypoxic respiratory failure.

At our center over the last few years, we have standardized an approach to monitoring and maintaining the weights of our AML patients at or near their pre-admission level with IV fluids and diuresis, as needed. We report outcomes of regimented weight monitoring on morbidity and mortality during AML induction.

METHOD

We conducted a retrospective chart review of newly diagnosed AML patients treated at our center between January 2016 and May 2022. The cohort was divided into 2 groups; those treated prior to 2019 and those treated after. For each group, patients whose weights were monitored and maintained within 3 kilograms of admission weight were identified for comparison with those who were not. Induction regimens including 7 plus 3 with or without the addition of targeted therapies were reviewed. Patients who were ineligible for induction and those admitted directly to the ICU prior to the start of therapy were excluded from this study.

We reviewed the records of 155 patients induced at our center; the mean age at diagnosis was 56 years (20-82). 74 (48%) of these 155 patients were females. Prior to 2019, 73 patients were induced; 68 of these patients did not have monitored weights. Of these 22 were ICU transfers (detailed in Table 2). The 5 remaining patients had weights monitored and none were transferred to the ICU. After January 1st 2019, weights were followed and euvolemia was maintained in 32 patients, of whom 3 (9.4%) were transferred to ICU. Of the 50 patients after 2019 in whom weights were not maintained, 12 were transferred to the ICU (as summarized in Table 1).

Out of 155 patients, 118 patients did not have weights followed and had a weight change of more than 3 kilograms above or below from admission. Of these 118 patients, 34 were transferred to ICU. 37 patients had weights followed, of which 3 were transferred to ICU. (OR 0.22) (95% CI 0.06-0.75) (p=0.017). The characteristics, mean length stay (LOS) and reasons for ICU transfer have been detailed in table 1.

The mean overall length of stay (LOS) for all patients was 31.21 days. Mean LOS was 23.94(n=37) and 33.50(n=118) days for patients whose weights were and were not followed, respectively (mean difference of 9.56 days) (95 % CI of 4.8115-14.3085) (p<0.01).

Nineteen out of 160 patients died due to causes listed in Tables 1 and 2. Among the 37 patients in whom daily weights were maintained, 3 patients, all of whom were transferred to ICU, died during induction. Of 118 patients in whom daily weights were not maintained, 14 patients died in the ICU during induction, whereas 1 patient died in hospice after developing bacteremia and respiratory failure (OR 0.6059, 95 % CI= 0.1653-2.2205, p=0.4496).

DISCUSSION

Fluid overload is a significant concern in the treatment of AML. Our findings suggest that maintaining euvolemia and monitoring daily weights can effectively manage patients on the floor and prevent unnecessary ICU transfers. Although there are limitations to our study due to its retrospective, single-center nature but the cost-effectiveness and noninvasive mode of maintaining euvolemia support its potential application to standard treatment protocols. As we have demonstrated, this simple intervention may contribute to reducing ICU transfers, LOS and overall mortality during induction therapy for AML patients. Further prospective studies are warranted to validate these findings.