Did monitoring standards influence outcome?

[French and foreign recommendations for the practice of anesthesia-intensive care]

This article reviews the development of STANDARDS, Recommendations and Guidelines for practice in anaesthesiology in France and other countries. The French society for anaesthesia and intensive care (Sfar) has published, since 1989, 11 basic

STANDARDS

1) Recommendations for the monitoring of patients during anaesthesia (June 1989, amended on January 1994) [APSF Newsletter, Summer 1990, page 22]; 2) Recommendations for postanaesthesia monitoring and care (September 1990); 3) Recommendations for preanaesthesia care (September 1991); 4) Recommendations for anaesthetic apparatus and checking before use (January 1994); 5) Recommendations for the equipment of anaesthesia working places (January 1995); 6) Recommendations for the tasks of the nurse anaesthetist (January 1995); 7) Recommendations for hygiene standards in anaesthesia practice (December 1997); 8) Recommendations for outpatient anaesthesia (September 1990); 9) Recommendations for the practice of obstetrical analgesia (September 1992); 10) Recommendations for interhospital physician-accompanied transfers (December 1992); 11) Recommendations for intrahospital physician-accompanied transfers (February 1994). Additionally the Sfar produced or coproduced 9 Experts' conferences, 15 Consensus conferences and 5 Guidelines for clinical practice.

Fatal and non fatal cardiac arrests related to anesthesia

PURPOSE

The aim of this study was to assess the incidence and causes of cardiac arrests related to anesthesia.

METHODS

All patients undergoing anesthesia over a six year period were included in a prospective study. The cardiac arrests encountered during anesthesia and the first twelve postoperative hours in the PACU or ICU were analysed. For each arrest, partially or totally related to anesthesia, the sequence of events leading to the accident was evaluated.

RESULTS

Eleven cardiac arrests related to anesthesia were identified among the 101,769 anesthetic procedures (frequency: 1.1/10,000 [0.44-1.72]). Mortality related to anesthesia was 0.6/10,000 [0.12-1.06]. Age over 84 yr and an ASA physical status > 2 were found to be risk factors of cardiac arrest related to anesthesia. The main causes of anesthesia related cardiac arrest were anesthetic overdose (four cases), hypovolemia (two cases) and hypoxemia due to difficult tracheal intubation (two cases). No cardiac arrests due to alveolar hypoventilation were noted during the postoperative periods in either PACU or ICU. At least one human error was noted in ten of the eleven cardiac arrests cases, due to poor preoperative evaluation in seven. All cardiac arrests totally related to anesthesia were classified as avoidable.

CONCLUSION

Efforts must be directed towards improving preoperative patient evaluation. Anesthetic induction doses should be titrated in all ASA 3 and 4 patients. The prediction of difficult tracheal intubation, and if required, the use of awake tracheal intubation techniques, should remain a priority when performing general anesthesia.

Influence of pulse oximetry and capnography on time to diagnosis of critical incidents in anesthesia: a pilot study using a full-scale patient simulator

OBJECTIVE

Many studies (outcome, epidemiological) have tested the hypothesis that pulse oximetry and capnography affect the outcome of anesthetic care. Uncontrollable variables in clinical studies make it difficult to generate statistically conclusive data. In the present study, we eliminated the variability among patients and operative procedures by using a full-scale patient simulator. We tested the hypothesis that pulse oximetry and capnography shorten the time to diagnosis of critical incidents.

METHODS

A simulator was programmed to represent a patient undergoing medullary nailing of a fractured femur under general anesthesia and suffering either malignant hyperthermia, a pneumothorax, a pulmonary embolism or an anoxic oxygen supply. One hundred thirteen anesthesiologists were randomly assigned to one of two groups of equal size, one with access to pulse oximetry and capnography data and the other without. Each anesthesiologist was further randomized to one of the four critical incidents. Each anesthetic procedure was videotaped. The time to correct diagnosis was measured and analyzed.

RESULTS

Based on analysis of 91 of the subjects, time to diagnosis was significantly shorter (median of 432 s vs. >480 s) for the anoxic oxygen supply scenario (p = 0.019) with pulse oximetry and capnography than without. No statistical difference in time to diagnosis was obtained between groups for the other three critical incidents.

CONCLUSIONS

Simulation may offer new approaches to the study of monitoring technology. However, the limitations of current simulators and the resources required to perform simulator-based research are impediments to wide-spread use of this tool.

Pulse oximetry and capnography in anaesthetic practice: an epidemiological appraisal

In the evaluation of any medical technology the efficacy, effectiveness, and efficiency must each be considered before routine deployment is recommended. Since the widespread practice of patient monitoring by pulse oximetry and capnography has occurred before the performance of rigorously controlled trials, definitive proof of worth is lacking. The purpose of this review is to appraise critically the effectiveness of this technology. The assessment was performed using concepts developed in epidemiology and community medicine to establish a given factor to be causative to a given outcome. The current literature pertaining to anaesthetic adverse outcomes was reviewed, and the use of monitors evaluated against the criteria of a causal relationship. While the conclusions are based more on the absence of positive data (owing to low frequency of adverse anaesthetic occurrences) rather than negative results, it must be concluded that the effectiveness of such monitoring has yet to be demonstrated. Such a conclusion should not detract from their use, for the role of an individual factor in the complex chain of accident evolution will seldom be demonstrable. Rather, such an appraisal should encourage a clear perspective of the depth of our clinical science, and encourage more rigorous critical evaluation in the future.

A unified approach to providing general anaesthesia monitoring with special reference to developing countries

Information concerning general anaesthesia, monitoring and ergonomics has been assembled to present a plan for the introduction of necessary monitors into a department of anaesthesia. This includes reference to: (i) The need for instrumental monitors; (ii) Division of tasks between anaesthetist and monitor; (iii) User education; (iv) Anaesthetist/monitor interface; (v) Hospital infrastructure. Emphasis is placed on the continued need for anaesthetists to employ their own senses for monitoring in the traditional manner and the essential role instrumental monitors should play in helping trainees to refine and calibrate their clinical skills. It is suggested that in situations where neither mechanical ventilators are available nor instrumental monitors necessary to refine the conduct of general anaesthesia a transitional stage in evolution could be the presence of two persons with clearly defined responsibilities for all the anaesthesia tasks necessary during a safely conducted case.