The Lack anaesthetic system

Comparison of the Magill and Lack Anaesthetic Breathing Systems in Anaesthetized Patients

“…There is also a difference from our reported findings with the Lack system in awake volunteers, in whom the fresh gas flow rate needed to prevent rebreathing was of the order of minute volume [7], whereas in the present study fresh gas flow rates approximating to alveolar minute volume were adequate. This difference may be caused by anaesthesia, change in breathing pattern or because of differences in carbon dioxide production.…”

“…The fresh gas flow rate required to prevent rebreathing with the coaxial version of the Mapleson A (Lack system) has also been the subject of controversy. Barnes, Conway and Purcell [7] noted that the Lack system was somewhat less efficient than the non-coaxial A system in conscious volunteers. Norman, Nott and Walters [8] showed the two systems to be equally efficient.…”

The Lack anaesthetic system

“…'e2 Limitations of function of the prototype were noted, corrected and published2 6 months before the Westminster paper. 3 As a matter of interest it was investigation of the expiratory resistance of this circuit, said by Westminster to be unacceptable3 although it was only 75/, over limit,4 that led to the work of Nott' demonstrating that the resistance of new Heidbrink valves was on average 459.6 higher than acceptable (though we had all been using these for years quite satisfactorily).…”