Influences and predictors of unanticipated admission after ambulatory surgery

In order to plan the daily routine of a surgical day care unit optimally an d effectively, it is indispensable to know the causes of unanticipated admi ssion of outpatients. The purpose of this experiment was to evaluate the in fluences and predictors of unanticipated admission of patients in our day c are unit for ambulatory surgery. The data sets of 3152 surgical outpatients were evaluated. The duration of slay had been entered online by computers. Method. From January 1997 until June 1999, all clinically relevant paramete rs from any out patient were entered into an anesthesia information managem ent system (NarkoData(R), Imeso GmbH, Huttenberg-Rechtenbach, Germany). The correlation of potential nominal and ordinal scaled predictors of unantici pated admission was tested using the chi-squared test. Univariate analysis was used in determining predictors for the occurrence of unanticipated admi ssion. Pearson's contingency coefficient (CC) was used as a standard for th e correlation rigidity in nominal and ordinal scaled parameters. The correl ation standard eta was used for metrical parameters. Results. Unanticipated admission occurred in 169 (5.4%) of the 3152 outpati ents. The following parameters significantly influenced unanticipated admis sion: age, ASA status, diagnosis (ICD-9),time of admission, different anest hesia procedures and anesthetics (opioids and nondepolarizing muscle relaxa nts),surgical department, type of surgery (ICPM), duration of operation, bl ood loss, intraoperative hemoglobin values, and the administration of collo id and crystalloid solutions. The parameters blood loss, intraoperative hem oglobin values, and administration of colloid solutions were evaluated as b eing good predictors. Conclusion. The causes of unanticipated admission of patients in our day ca re unit for ambulatory surgery are manifold. Some relate to the patient,the anesthesia, and the organization of the day care unit, whereas lengthy ope rative trauma leading to intraoperative blood loss also plays a major role.