Gaither B. Everett

An evaluation of cardiorespiratory effects of posture in the dental outpatient

T he problems of posture relative to maintenance of a natural relationship between the head and body during dental operations were emphasized as long ago as 189&l The upright sitting posture was accepted until 195’7, when it was suggested that the common fainting attack could occur unrecognized under outpatient anesthesia and result in permanent brain damage or, indeed, death.2 Studies of the problems relative to cardiorespiratory effects of posture are inconc1usive.3-6 Therefore, we attempted to determine and establish control measurements of cardiorespiratory and peripheral blood flow responses exhibited by (1) the unpremeditated, unanesthetized patient positioned in the five postures shown in Fig. 1 and (2) two comparable groups of six persons, each selected at random, stressed with sleep doses of intravenous methohexital in the 45 degree upright sitting position (Position 4) and in the Trendelenburg position (Position 5). If dental operations are performed on patients in the supine position, then to ensure maintenance of a patent airway and prevention of laryngeal soiling by stomach contents, endotracheal intubation becomes mandatory. The assumption in clinical practice is that Positions 4 and 5 avoid these problems (Appendix).

A Comparison of the Cardiorespiratory Effects of Methohexital and Thiopental Supplementation for Outpatient Dental Anesthesia

There has been great disparity in the reported results of the cardiorespiratory effects of methohexita11.4,j as, indeed, of thiopental.6 These differences are related to differences in methods of administration, prernedication, and supplementation of the anesthesia. As outpatient dental anesthesia differs from surgical anesthesia in a hospital environment,T we evaluated the cardiorespiratory effects of the two agents in a controlled situation simulating outpatient oral surgical practice.