Chemotherapy alters cisatracurium induced neuromuscular blockade characteristics: A prospective cohort study.

STUDY OBJECTIVE: To compare the characteristics of NMDR induced muscle paralysis in breast cancer patients with and without a history of recent chemotherapy with cyclophosphamide, doxorubicin and 5-fluorouracil (CAF) regimen.

DESIGN: This is a non-randomized prospective cohort study.

SETTING: Operating room of a university-affiliated teaching hospital.

PATIENTS: Out of a total of 50 patients who had undergone mastectomy, 22 patients were allocated to the "Chemo group" and 28 patients to the "Non-Chemo group", based on a valid history of recent chemotherapy.

INTERVENTION: After induction of anesthesia with thiopental and cisatracurium, neuromuscular monitoring was started for all patients.

MEASUREMENTS: Initially the time to 100% single-twitch (ST) suppression was measured. Then, the time for the appearance of the first response to post-tetanic count (PTC) stimulation, Train-of-Four (TOF) stimulation, and TOF50% were measured consequently.

MAIN RESULTS: Time to get STzero was significantly longer in the Chemo group than in the Non-chemo group. Time for the appearance of the first response of PTC and TOF and TOF50% was significantly shorter in the Chemo group than the other group. The mean duration of intense block was 27.66 minutes in the Chemo group versus 42.47 minutes in the Non-chemo group.

CONCLUSION: This research demonstrated that in patients having undergone chemotherapy, the effect of NDMRs starts with a longer lag time and finishes earlier too. Thus, these patients are ready for intubation after a longer time. Moreover, we have to repeat cisatracurium injections after shorter intervals to maintain the desired level of blockade.