Constant Flow Ventilation in Anesthetized Patients

Abstract

Constant f 7 0~ ventilation (CF V ) inninfains iioririal gas ex-change in apneic dogs rind has potential clinical application during thoracic surgery or pulmonary edeina. We compared CFV and interniittent positive pressure ventilation (IPPV) in five healthy, anesthetized, (fentanyl, diazepam, and nitrous oxide) and paralyzed patients undergoing nonthoracic operations. Coiistnrit f7ow ventilation was delivered at a total flow of 0.9-1.6 L-kg 'min ~ I (riitrous oxide-oxygen o f 2 : l i into two tubes of 2.5-3.5 tmn inner dianieter n ftnched to each side of an 8-9 mm inner diameter orotraciieal tube (OTT). Under brochoscopic p i d a n c e , the CFV-OTT iuas adzlanced to positioii each ueiitilntiri<y tidient n in~riiistrni hroncliial orifice. Gns exlinirskd t/irciir<yIi the OTT I u i n c i i . lf intunthoracic ~~ressiir' excredcd n preset liiiiit, a soleii~iid m l v c automticnlly interrupted gas fliiiu to the patient to prcuciit barotrniirnn. Coiiipared to IPPV, during CFV for u p to 30 riiiri nzlcrii<ye P~c o~ increased to 69.2 IC_ 14.5 f r o i i i 35.9 k 2.9 m i 1 H<y, rc~fl~cfin~y n ccrlriilated nli~eolar z l e i itilation (V,J of46 ? 22% of the eucapiiic I c z d . We sug<ycst that n technique corribiniiig CFV 17t lomcr Poz(i rates ziiitli IPPV may prom clinically useful by alloioiiis dccrensed t i l f n l z~olunie a i d iiispiratoty pressure iiiliile iiiniiitiiiiiiiig norinnl VA.

Low-Flow Endobronchial Insufflation With Air for 2 Hours of Apnea Provides Ventilation Adequate for Survival

“…In clinical experiments, where 50%-100% oxygen was used for EI, flows needed to maintain adequate oxygenation ranged between about 0.5 L.kg-l.rnin-* (7,17) and 1.6 L.kg-'.min-' (16). Paco, levels ranged from 55 to 69 mm Hg after 8-30 min of EI.…”

Apnoeic oxygenation in paediatric anaesthesia: a narrative review

“…Children receiving apnoeic oxygenation typically experienced less arterial oxygen desaturation when compared with children whose tracheas were intubated in those departments before implementation of the technique (Table 1). However, these before-after studies often animal model, which yielded sufficient carbon dioxide clearance to achieve a normoventilatory state [42], a state that has not been consistently replicated in humans [43,44].…”

“…Higher flow rates are believed to extend the region of turbulent gas flow more distally in the airways, resulting in improved gas exchange. An extreme illustration of these measures is the experimental use of high‐flow bronchial catheters in an animal model, which yielded sufficient carbon dioxide clearance to achieve a normoventilatory state [42], a state that has not been consistently replicated in humans [43,44]. In the context of high‐flow nasal oxygen, the site of administration is fixed at the nose but the flow rate is modifiable.…”

Η Επίδραση Της Εμφύσησης Οξυγόνου Στον Αερισμό Τραχειοστομημένων Ασθενών Της ΜΕΘ Κατά Την Αποδέσμευση Από Τον Αναπνευτήρα

“…ασθενής από 35 mm Hg σε 55 mm Hg, ενώ σε έναν παρέμεινε φυσιολογική. Οι Breen et al(1986)180 εφήρμοσαν παροχή οξυγόνου από 0.9 -1.6 L/Η…”