Anesthesia and analgesia
-
Anesthesia and analgesia · Sep 1998
Postanesthesia care unit length of stay: quantifying and assessing dependent factors.
Postanesthesia care unit (PACU) monitoring reduces morbidity and is the standard of care for postsurgical patients. PACUs require large nurse to patient ratios, which contributes to the cost of care. Despite the importance and cost of PACU length of stay (LOS), no standards have been established. We performed an observational study of 340 PACU patients to measure actual and medically appropriate PACU LOS (the time required to achieve a medically stable condition for safe PACU discharge), to identify factors related to LOS, and to create a LOS prediction index. Mean (+/- SD) actual LOS was 95+/-43 min, and appropriate PACU LOS was 71+/-37 min. Appropriate PACU LOS predictors were anesthetic time, anesthetic technique, and amount of intraoperative fluids. Actual LOS was >30 min longer than the medically appropriate LOS for 20% (68 of 340) of the patients. Frequent causes of excessive LOS were waiting for physician release or laboratory or radiographic results. Appropriate LOS may be related primarily to anesthetic factors, and nonmedical issues account for a significant amount of PACU LOS. ⋯ Most patients are stabilized immediately after surgery in a postanesthesia care unit (PACU) until their discharge to a hospital ward. However, there are no standards for appropriate PACU length of stay (LOS). In this study, we measured actual and appropriate PACU LOSs and evaluated clinical factors that may influence PACU LOS.
-
Anesthesia and analgesia · Sep 1998
The effects of desflurane on cardiac function as measured by conductance volumetry in swine.
The purpose of the investigation was to assess the effects of desflurane (DES) on left ventricular heart function during basal barbiturate anesthesia in a closed-pericardium, closed-chest acute swine model. The study was performed in 11 normoventilated adult pigs. Hemodynamic measurements were obtained using arterial, central venous, and pulmonary artery catheters, as well as a conductance volumetry and tip manometry catheter placed in the left ventricle. Hemodynamic measurements were recorded during basal pentobarbital anesthesia and with the addition of 1%, 2%, 4%, and 6% DES. DES dose-dependently decreased mean arterial pressure, systemic vascular resistance, left ventricular end-systolic pressure, dP/dtMAX and dP/dtMIN. At doses >1%, decreases in CO, stroke volume, ejection fraction, end-systolic elastance, preload recruitable stroke work, preload adjusted maximal power, and peak filling rate were observed. Heart rate decreased at 4% and 6% DES. Isovolumetric relaxation time increased only at 6% DES. We conclude that smaller doses of DES have a significant cardiodepressive effect in the setting of barbiturate infusion, as measured by conductance volumetry. ⋯ Desflurane, in very small doses, depressed cardiac function during pentobarbital anesthesia with ketamine and benzodiazepine premedication in swine, as assessed by conductance volumetry and left ventricular pressure and volume relationship analysis. These results suggest that desflurane, in combination with certain anesthetics, can be cardiodepressive even in very small doses.