Tracheostomy for Acute Respiratory Failure

Washout of Anatomical Dead Space. Design of a Method and Experimental Study Using an External Dead Space

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One of the objectives of tracheostom y in cases of advanced pulm o n ary em physem a is a reduction in anatom ical dead space [4,5,6,9,14,18]. I t is held th a t tracheostom y should be postponed u n til an acu te d eterioration of the p a tie n t's condition m akes its in stitu tio n m an d ato ry [6,18].

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“…I t is held th a t tracheostom y should be postponed u n til an acu te d eterioration of the p a tie n t's condition m akes its in stitu tio n m an d ato ry [6,18]. In view of th e im provem ent of v en tilato ry fu n c tion afte r tracheostom y [6,9,14,17] it appears justified, however, to stu d y the effect of reduction of anatom ical dead space in these p a tie n ts before onset of an acute episode of respiratory failure so as ev en tu ally to take steps aim ed at perm anent reduction of dead space.…”

“…I t is held th a t tracheostom y should be postponed u n til an acu te d eterioration of the p a tie n t's condition m akes its in stitu tio n m an d ato ry [6,18]. In view of th e im provem ent of v en tilato ry fu n c tion afte r tracheostom y [6,9,14,17] it appears justified, however, to stu d y the effect of reduction of anatom ical dead space in these p a tie n ts before onset of an acute episode of respiratory failure so as ev en tu ally to take steps aim ed at perm anent reduction of dead space.At th e end of expiration dead space betw een the carina and th e ex tern al orifices of th e airw ays m ainly contains air w ith the com position of alveolar air; could this p a rt of dead space be elim inated, tid al air would be decreased by a corresponding volum e. F urth erm o re, C 0 2 norm ally contained in this p a rt of th e airw ays no longer would be re b rea th e d , leading to a decrease in m inute ventilation as a physio logical response set to m aintain the existing P a C 0 2 level [21], The decrease in m inute volum e of v en tilatio n will th u s be determ ined by the influence of reduction in dead space on the P a C 0 2 level. E ven in conditions of chronic hypercarbia this level is kept in a ra th e r narrow range th roughout daily fluctuations [3], W henever increase in respira tory dead space is a prom inent pathological feature, reduction in its size should be valuable.…”

Tracheostomy in Acute Respiratory Failure: Effects Assessed by Arterial Blood Gases

“…Bruderman et al (12) claimed that arterial CO 2 tension was reduced dramatically with controlled ventilation, and much more slowly with IPPB. In our series, the decline in hypercapnia was related primarily to the relief of secretional obstruction followed by assisted ventilation.…”

Washout of Anatomical Dead Space for Alveolar Hypoventilation

“…In recent years, admixture of oxygen to inspired air has been reported as being clinically beneficial [1,2,3], particularly with respect to the low exercise tolerance in chronic hypoxemia. Another approach to support ventilation in such conditions is reduction of anatomical dead space by tracheostomy in states of CO, retention [4,5,6,7]. This study presents preliminary clinical evaluation of a method to clear part of anatomical dead space from exhaled air by flushing dead space (washout), using a small cannula inserted into the trachea either by needle tracheostomy or via an existing tracheostoma.…”