High-flow nasal oxygenation for anesthetic management / 대한마취과학회지

High-flow nasal oxygenation (HFNO) is a promising new technique for anesthesiologists. The use of HFNO during the induction of anesthesia and during upper airway surgeries has been initiated, and its applications have been rapidly growing ever since. The advantages of this technique include its easy set-up, high tolerability, and its abilities to produce positive airway pressure and a high fraction of inspired oxygen and to influence the clearance of carbon dioxide to some extent. HFNO, via a nasal cannula, can provide oxygen both to patients who can breathe spontaneously and to those who are apneic; further, this technique does not interfere with bag-mask ventilation, attempts at laryngoscopy for tracheal intubation, and surgical procedures conducted in the airway. In this review, we describe the techniques associated with HFNO and the advantages and disadvantages of HFNO based on the current state of knowledge.

High-flow nasal oxygenation for anesthetic management / 대한마취과학회지

High-flow nasal oxygenation (HFNO) is a promising new technique for anesthesiologists. The use of HFNO during the induction of anesthesia and during upper airway surgeries has been initiated, and its applications have been rapidly growing ever since. The advantages of this technique include its easy set-up, high tolerability, and its abilities to produce positive airway pressure and a high fraction of inspired oxygen and to influence the clearance of carbon dioxide to some extent. HFNO, via a nasal cannula, can provide oxygen both to patients who can breathe spontaneously and to those who are apneic; further, this technique does not interfere with bag-mask ventilation, attempts at laryngoscopy for tracheal intubation, and surgical procedures conducted in the airway. In this review, we describe the techniques associated with HFNO and the advantages and disadvantages of HFNO based on the current state of knowledge.

Gastric emptying of indigestible solids - A rat model

The effects of ingestion of digestion of digestible solids and liquids on gastric emptying of indigestible solids were studied. Thirty rats were allocated to one of five groups; in four groups, rats had been fasted for 24 h before the experiment, whereas in the fifth group, they had not been fasted. In all groups, ten steel balls [1.0 mm in diameter] were inserted through an orogastric cannula into the stomach under brief halothane anesthesia. In the four groups of fasted rats, one of the following substances was then given into the stomach: [1] 0.5 g digestible solids; [2] 1.0 ml saline; [3] 1.0 ml contrast medium [45% wv sodium diatrizoate]; [4] no substance [control group]. Three hours later, the number of balls which had passed into the intestine was counted. Ingestion of 0.5 g meal in fasted rats significantly delayed gastric emptying of steel balls [P << 0.001], whereas there was no difference in gastric emptying of steel balls between fasted rats and fully fed rats. Ingestion of the contrast medium [P << 0.001], but not that of saline, significantly delayed the emptying of the balls. Therefore, ingestion of digestible solids or liquids may delay gastric emptying of indigestible solids. Clinical implications of gastric emptying of indigestible solids are discussed

Use of the laryngeal mask for closed circuit anesthesia

We examined whether the laryngeal mask could be used effectively in 70 patients breathing spontaneously during closed-circuit anesthesia. After administration of oxygen 101 min[-1], anesthesia was induced and the laryngeal mask inserted. After 6 min of denitrogenation [3.51 min[-1] nitrous oxide and 1.51.min[-1] oxygen], the fresh-gas flow was decreased to the minimum required to maintain refilling of a ventilator bellows [Carden Ventmasta]; nitrous oxide was turned off. A vaporiser outside the breathing system was set either by observing an end-tidal agent monitor or at 3-5 times greater than the required end-tidal concentration. The total fresh gas flow, hemodynamics and respiratory variables were monitored. Several types of operations were performed and lasted 9-126 min [mean 37 min]. The average total fresh gas flow during the closed circuit period was 340 ml. min[-1] [range 200-500 ml. min[-1]]. Blood pressure, heart rate and respiration were stable throughout anesthesia and there were no major side effects attributable to the technique. We believe that closed-circuit anesthesia in patients breathing spontaneously through the laryngeal mask, as described here, can be used safely, conveniently and effectively. This technique is suitable for surgical operations of short duration