This study reports data derived from a self-reported questionnaire from obstetric anesthesia unit directors. The study found that total number of deliveries was a poor measure of obstetric anesthesia workload. The OAAI is a workload-directed performance indicator and better reflects the obstetric anesthesia workload than merely measuring the total number of deliveries. Use of the annual number of deliveries as the bench-mark comparator for maternity services will under-estimate obstetric anesthesia activity in centers with high epidural rates and will over-estimate it in centers with low epidural rates. Consequently, the OAAI may be useful as a denominator in obstetric anesthesia workforce staffing calculations.
There was a wide range of demand for different obstetric anesthesia services among the different hospitals. However, there was no clear relationship between the allocation of obstetric anesthesia workforce to labor wards in Israel and the obstetric anesthesia workload as measured by the OAAI.
Ensuring adequate staffing levels for obstetric anesthesia units is important for both patient satisfaction and patient safety. From our previously published data, hospitals with a dedicated anesthesiologist in the labor ward 24 h per day/7 days per week had a two-fold increase in the epidural rate and half the epidural waiting time, when compared to hospitals where the anesthesiologist had to be called from the operating room. In addition to the provision of analgesia, a functioning epidural catheter can be used for the provision of epidural surgical anesthesia for urgent cesarean delivery without the need for potentially hazardous emergency general anesthesia. Maternal death due to anesthesia is the sixth leading cause of pregnancy-related death in the United States and most anesthesia-related deaths occur during general anesthesia for urgent cesarean delivery. The risk of maternal death from complications of general anesthesia is 17 times that associated with regional anesthesia. Therefore, the finding in our earlier study that there was an inverse relationship between the epidural rate for labor analgesia and the choice of general anesthesia for emergency cesarean delivery suggests that inadequate obstetric anesthesia workforce supply may have adverse effects on patient safety. Other studies have reported the adequacy or inadequacy of obstetric anesthesia workforce in relation to total delivery numbers. The current study is the first stage in an approach that will attempt to define the adequacy of obstetric anesthesia workforce in relation to activity.
The epidural component of the OAAI includes time taken for pre-analgesia assessment, sterile preparation, block placement, incremental drug dosing (over several minutes), and at least 15-20 min bedside observation following completion of drug administration. A labor epidural should never take less than 30 min, and typically takes in the region of 45 min. The time spent on anesthesia for cesarean delivery is rarely less than 90 min although surgical time varies between hospitals, surgeons, and patient risk-factors, and time spent waiting for post-anesthesia care unit.
Like any composite measure, the OAAI does not specifically identify the individual predominant contributing component. The OAAI ignores requests to provide supplementary epidural analgesia throughout labor, although this element can be greatly reduced by the use of patient-controlled analgesia pumps. The OAAI ignores clinical activities other than epidural analgesia and cesarean anesthesia (including anesthesia for retained placenta and complicated vaginal deliveries, antenatal or pre-operative consultation, and resident training). In some centers, the obstetric anesthesia team also provides anesthesia services for non-obstetric gynecological operations and for post-anesthesia care units. The OAAI cannot account for lengthy epidural analgesia and cesarean deliveries or differentiate between day/night/weekend shifts and experience of personnel. Accordingly, the OAAI is not a measure of the total activity of the obstetric anesthesia services.
Based on these limitations, it is important to appreciate that although the OAAI is numerically identical to the time (in hours) spent engaged in epidurals and cesareans in an average 24 h period, the OAAI is a dimensionless index of activity and is not a measurement of time.
Additionally, the OAAI does not consider the degree of workforce redundancy that is required to safely accommodate extra workload during peak activity or provide expert back-up when the maternity services are located in remote locations away from the main anesthesia services. Provision of back-up is particularly important when considering emergency cesareans and the data could not differentiate between elective and emergency cesarean delivery. Finally, while it is obvious that coupling exists, as the OAAI is derived from both epidural rates and cesarean rates, it is precisely for this reason that this single denominator is a more reliable measure of activity than annual delivery numbers.
A limitation of the data upon which this secondary analysis is based is that data were self-reported and not corroborated; in almost all cases data were approximated by the unit directors. Part of the explanation for this finding is that many hospitals have no computerized data management system. A national observational study is underway in Israel to assess the obstetric anesthesia workforce supply and work load demand ratio, based on the OAAI, and to correlate this with quantifiable measures of adequacy of obstetric anesthesia services. That study may provide corroboration for the data presented in this study and will attempt to identify an ideal obstetric anesthesia staffing number based on the OAAI.
In summary, the use of the OAAI may facilitate a comparison of the workforce supply – workload demand ratio (and defined obstetric outcomes) for hospitals with different geographical (center versus periphery) and cultural (ultra-Orthodox Jews, Arabs and Bedouins, versus heterogeneous) demographic populations. Such studies may provide the data to support a change in health care resource allocation, to provide obstetric anesthesia workforce commensurate with obstetric anesthesia workload demands, and to provide uniform levels of care throughout the country. Based on these studies, it is possible that future recommendations for obstetric anesthesia staffing ratios will need to use the OAAI, or a similar index, as a single workload denominator.