Research Article

The Effect of Minimal, Low and Medium Flow Anesthesia on Intraoperative Neuromuscular Blocker Consumption: Prospective Cohort Study


  • Güvenç Doğan
  • Selçuk Kayır
  • Emre Demir
  • Yasemin Yavuz
  • Volkan Hancı

Received Date: 29.06.2019 Accepted Date: 30.10.2019 J Ankara Univ Fac Med 2019;72(3):356-361


The aim of this study was to determine whether there would be an increase in the need for intra-operative neuromuscular blocker consumption due to better preservation of body temperature in low flow anesthesia. In this study, the effects of minimal, low and medium flow anesthesia on intra-operative neuromuscular blocker consumption were investigated.

Materials and Methods:

The study involved 120 patients aged between 18 and 75 who would have an operation in elective conditions under general anesthesia for approximately 90 to 120 minutes ASA I-III. The patients were randomly divided into three groups as minimal flow (n=40), low flow (n=40), and medium flow (n=40). Nasopharyngeal body heat, heart rate, systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, and peripheral oxygen saturation were recorded in the 1st, 5th, 10th, 15th, and 30th minute after induction and in every 30 minute later; FiSevo, FeSevo, FiO2, FCO2, minimum alveolar concentration values and EtCO2 were recorded in the 5th, 10th, 15th, and 30th minute after induction and in every 30 minute later.


The time of intubation was similar between the groups (p=0.727: minimal flow=106.12±38.94, low flow=110.87±38.04, medium flow=104.45±34.80 seconds). The time of the first additional dose was similar between the groups (p=0.476). The time of the second additional dose was similar (p=0.317). No significant differences were found between the groups in terms of the 1st and 2nd additional dose neuromuscular blockers amount (p=0.170, p=0.214).


Minimal flow anesthesia is considered to have an effect on the increase in the use of neuromuscular blockers formed by rocuronium, yet this effect is considered to be limited. Minimal flow anesthesia ensures that operating room air remains clean, reduces operating costs and increases humidity and temperature in the breathing circuit. It is an anesthetic method that should be encouraged because it provides better physiological respiratory conditions and reduces intraoperative hypothermia.

Keywords: Minimal Flow, Low Flow, Medium Flow, Anesthesia, Neuromuscular Blocker

Full Text (Turkish)