Change in tracheal blood flow during endotracheal intubation

Abstract

Changes in blood flow in the tracheal mucosa of the dog caused by the pressure exerted by high volume, low-pressure cuffs were measured with the hydrogen clearance method. Before inflating the cuffs, the blood flow of the tracheal mucosa was measured as a control for 12 h in order to confirm that the procedures of the hydrogen clearance method itself had little or no influence on the blood flow in the tracheal mucosa. After inflating the cuffs to create a tracheal wall pressure (TWP) of 1.3 kPa (10 mmHg), 2.6 kPa (20 mmHg), 3.9 kPa (30 mmHg) or 6.0 kPa (45 mmHg), local blood flows of tracheal mucosa (TBF) corresponding to each TWP were measured every hour for 12 h. No significant changes in blood flow were observed in the tracheal mucosa with the hydrogen clearance method before inflating the cuffs. In the groups with TWP of 1.3 and 2.6 kPa, the TBF rose 1 h after inflation of the cuffs, and then returned to the baseline values. In the group with TWP of 6.0 kPa, the TBF decreased markedly already 1 h after inflation of the cuffs, and continued to decrease severely thereafter. In the group with TWP of 3.9 kPa, the TBF followed an intermediate course between the groups with TWP of 2.6 kPa and 6.0 kPa. From the results of the present study, it was found that TBF was significantly impaired by a TWP of more than 3.9 kPa. Therefore, in prolonged intubation, TWP should be kept at or below 2.6 kPa.

Less perilaryngeal gas leakage with SLIPATM than with LMA-ProSealTM in paralyzed patients

“…10 Of course, the LMA-ProSeal exerts pressure on the pharyngeal structures similar to other inflatable airway devices. 11,12 Several studies have reported the association of using an LMA-ProSeal with injuries to the lingual and recurrent laryngeal nerves. 13,14 The four cases of perilaryngeal leakage during pneumoperitoneum in the LMA-ProSeal group could be explained by displacement of the LMAProSeal caused by diffusion of N 2 O into the cuff.…”

Laryngeal mask airway cuff pressure and position during anaesthesia lasting one to two hours

“…The tracheal tube (TO cuff expands within the rigid confines of the tracheal rings and it has been shown that a large reduction in tracheal blood flow occurs at cuff pressures >20 mmHg, 7 A pressure in a tracheal cuff >50 mmHg for only 15 min can destroy columnar epithelium and will partially denude the basement membrane. 8 The relationship between mucosal pressure and LMA cuff pressure is more complex. Unlike the trachea, the pharynx is a highly distensible structure which is normally subject to large transient pressure changes and distortion under many physiological conditions.…”

Complicações das vias aéreas relacionadas à intubação endotraqueal

“…Pesquisas clínicas têm demonstrado diversos tipos de lesões de mucosa laríngea e traqueal após a intubação por períodos variáveis de tempo, sendo este um dos fatores determinantes do agravamento das lesões 9,10 . Devido à configuração da glote em "V", as principais lesões ocorrem na porção posterior da laringe, no nível dos processos vocais, onde a sonda encontra-se em íntimo contato com a mucosa.…”