Computer program helps maintain CALM during labour
By Alison DeLory
September 13, 2005 Volume 41 Issue 30
Dr. Emily Hamilton compares the role of the obstetrician tracking a woman's labour to that of a pilot flying a plane. Conditions change constantly and one speedometer is not enough to guide the plane to safety. A variety of tools and measurements must be consulted during the flight. Yet according to Dr. Hamilton, who delivered babies for 20 years before becoming a researcher, obstetricians in many hospitals don't have adequate resources to ensure the best possible outcomes for their patients.
"There has never been a good way of consistently measuring progress in labour or fetal well-being," said Dr. Hamilton, adding the standard of care is open to wide variation in interpretation.
Even today women are told to expect to dilate one centimetre per hour during labour. It's a measure that was developed in 1956 before epidurals were used, when cesarean section rates were 1.8% and forceps were used in more than half of all deliveries. Fetal monitors were introduced in the 1960s to give clinicians a tool to measure fetal well-being, yet one of the main contributors to preventable birthrelated brain injury today remains the delay or failure to recognize fetal distress, according to Dr. Hamilton. "That's how poor the state-of-the-art is."
The Montreal physician is concerned that both overuse and a delayed use of medical interventions contribute to errors in obstetrical care and preventable injuries. "Where there is great variation, there is great room for improvement."
Dr. Hamilton says rather than blaming obstetricians—who may be asked to make decisions based on poor or incomplete information, or whose judgment may be impaired by fatigue or conflicting priorities—she sought to fix the problem.
Her solution is the Computer Assisted Labour Management (CALM) system, an evidence-based approach to obstetrics. It is a clinical information system that includes surveillance, archiving and charting characteristics. The software is composed of decision-support modules and includes the CALM Curve and CALM Patterns.
The CALM Curve uses basic pelvic exam data and contraction information obtained during labour. The patient's progress in labour (dilation and station vs. time) is plotted along the CALM Curve, a representation of the mean and outer limits of a reference population under similar labour conditions. Calculations are updated at each exam and adjust for changing labour conditions such as contraction frequency or epidural use.
CALM Patterns uses the data from the fetal monitor to provide information back to clinicians, such as a condensed display of the tracing for viewing trends. It also provides a classification of risk based on standardized rules as defined by the institution.
As a result, CALM purports to optimize the care of the mother and her baby. For example, the analysis can highlight conditions associated with increased risk of uterine rupture, help determine when cesarean sections are indicated and therefore help reduce brain-related injuries in newborns.
L'Hôpital Sainte-Justine in Montreal handles nearly 4,000 births each year and uses the CALM system. Dr. Robert Gauthier, an ob/gyn at Sainte-Justine, said he finds the curve a very effective way to follow patients. "It provides a standardized approach in evaluating labour. With 40% of all cesareans performed due to failure to progress, this system really helps us to do better obstetrics. It provides me with information that was previously unavailable to support the diagnosis of dystocia. It offers objective and consistent data while always highlighting the normal limits of labour."
Dr. Gauthier also praises its usefulness for women attempting a vaginal birth after cesarean. "We are able to be more prudent and intervene earlier with a cesarean in order to prevent uterine rupture."
CALM incorporates 10 years of research on more than 11,000 patient records whose data form the reference populations. The project began in the 1990s when Dr. Hamilton, then a professor at McGill University, was questioning what is "normal progress" in labour. "Patients arrive (at hospital) at different stages of labour and progress differently," she said. Dr. Hamilton said she knew the way obstetricians evaluated labour was very subjective, and she wished to develop more quantitative measures.
Support for the project has been "extraordinary," said Dr. Hamilton. With funding from McGill and the province of Quebec she launched a research company in 1997 called LMS Medical Systems, where she now works full-time. The company sells CALM suites throughout North America with prices averaging $150,000.
In the U.S., she said studies in the 1990s out of the National Institute of Health showed that obstetrical errors were "undeniable. Judgment is fallible." There is further impetus for U.S. hospitals to use the system as a means of avoiding costly malpractice lawsuits. Obstetrics is one of the most litigated areas of medicine both in the U.S. and in Canada, but Dr. Hamilton said many Canadian suits are settled out of court while in the U.S. there is a possibility such cases will be tried by jury—something hospitals seek to avoid.
Another feature of CALM is that doctors who cannot always be at their patient's bedside can watch how their patient's labour is progressing through the Internet. Using a highly secure virtual network, doctors two blocks or 200 km away can access CALM data. "Through centralized monitoring, we've got all the patient tracings on the screen. We can see right away if there is a problem with a patient and get to her immediately," said Dr. Gauthier.
In the future, Dr. Hamilton will continue to focus on developing solutions for obstetrics. However, she said it's possible the CALM model could be modified and applied to other specialties that could benefit from standardization. She noted fluctuations in hysterectomy and corneal implant rates, and the subjectiveness used by cardiologists when deciding whether to implant stents, as examples. "When care is standardized, quality of care improves," said Dr. Hamilton.
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