Contemporary anesthesia practice最新文献

In a cost-conscious medical and social community, the surgeon and anesthesiologist must work as a unit to attain the goal of patient comfort during elective, cosmetic procedures in a safe, cost-effective, medically acceptable manner. A close-working relationship between the surgeon and anesthesiologist is mandatory with each being cognizant and understanding of the special problems encountered by the colleague.

The nonrebreathing system has been with us since Morton demonstrated the administration of diethyl ether in 1846. Its current popularity is evidenced by the extensive use of the Bain system. The greatest advantage, its history of patient safety, is related to the circuit's simplicity and the knowledge that the delivered concentration equals the inhaled concentration. Most disadvantages of the nonrebreathing system are related to the required high delivery rates: operating room and environmental pollution, necessity of scavenging gases, cost of agents, energy loss through no-return operating room ventilation, inhalation of dry gases, and the inability of the anesthesiologist to quantitate patient uptake of oxygen and inhaled anesthetics. Partial rebreathing systems reduce the disadvantages related to high delivery flow rates but, owing to the required rebreathing, do not permit the anesthesiologist to know the inhaled anesthetic concentration. A carbon dioxide absorber is necessary. It is still impossible to quantitate uptake by the patient, and it is difficult to conclude that any real net advantage results from the use of partial rebreathing systems. When modern-day technology provides the practitioner with an appropriate anesthesia machine, it is likely that closed-circuit anesthesia will become the method of choice for anesthesia delivery. Although the economic, ecologic, and physiologic advantages of this system are important, its greatest asset is the ability to monitor important respiratory and cardiovascular variables in patients noninvasively. Important information provided to the anesthesiologist by the patient during closed-circuit anesthesia is lost through the pop-off valve when high-flow systems are used. During closed-circuit anesthesia the gas machine itself becomes a monitor. Practicing anesthesiologists will embrace closed-circuit anesthesia practice when-and if-they are convinced that it provides an opportunity for better and more efficient patient care than other systems.

Research by the Advanced Biotechnology Group, Department of Anesthesiology, the University of Arizona, has led to the development of many of the physical and theoretic elements necessary to the creation of a new automated anesthesia delivery system. Recognizing the obligation to provide means of the highest reliability and safety for anesthesia delivery, this group is endeavoring to bring together a compact, integrated modular system of the greatest utility to the practicing anesthesiologist.

Although anesthetists have accomplished a remarkable safety record with commercially available anesthetic machines, these results have been obtained in spite of machine design, which could best be described as a nonsystem. In cases involving severely compromised patients, surgical procedures that severely alter patient physiology, and untoward events during "routine" anesthesia, it is a tribute to the flexibility and resourcefulness of anesthetists that more incidents do not occur. Industry has long sought precision, reliability, automatic control, and human-factors engineering in nonmedical applications, such as aircraft cockpit design, word-processing stations, and manufacturing processes. The relentless accretion of more and more nonintegrated gadgets onto an antiquated technology has exceeded the boundaries of proper function. Neither the patient nor the anesthetist is being served well by failure to implement state-of-the-art technology in anesthesic delivery systems. Anesthesiologists and others who are vitally interested in the welfare of their patients must insist that development of radically new integrated modular systems proceed at full speed. Their checkbooks can speak as loudly as the facts; it is time the manufacturers are aware that deep concern will be translated into purchasing decisions.