Originally published March 2014
The induction of labour is an important approach in the management of pregnancy. Oxytocin is a valuable medication used to induce or augment labour. As with all medications, the use of oxytocin has potential risks.
A review of the CMPA's medico-legal case files involving the administration of oxytocin during labour provides insights to better manage the risk of patient harm, adverse birth outcome, and potential medico-legal problems.
The 74 medico-legal cases related to labour induction or augmentation with an oxytocic agent opened by the CMPA between 2002 and 2012 confirmed the role played by a broad range of issues. In these cases, the clinical outcome for the babies was often a catastrophic injury or death. For physicians, the legal outcome was unfavourable in the majority of cases. In the closed legal actions, 75% resulted in a settlement. In the closed medical regulatory authority (College) cases, 70% ended in the expression of concern about the patient care.
In these cases, oxytocin was the most commonly administered medication, followed by prostaglandin E1 or E2 (i.e. misoprostol, dinoprostone).
The Institute for Safe Medication Practices includes intravenous oxytocin on its list of high-alert medications, recognizing that its use can potentially lead to maternal and fetal harm.1
Peer experts identify the issues
Peer experts who provided opinions in these cases identified a number of issues with induction of labour, which were similar to the issues encountered with augmentation.
Experts identified pre-induction issues that included failure to follow up on an atypical non-stress test and commencing inductions when not medically indicated. The latter reflects the growing concern in the obstetrical community related to the rising number of unwarranted inductions.
Consent problems arose when a physician failed to inform the patient of the potential risks related to induction with an oxytocic agent, such as excessive stimulation of the uterus or fetal bradycardia.
Two medication issues were most common in the cases. The first was the failure to discontinue the oxytocin infusion in the presence of an atypical or abnormal fetal heart rate pattern, or in the presence of tachysystole with corresponding fetal heart rate decelerations. The second issue was prescribing the wrong dose of oxytocin. Both low and high dose protocols exist. Nevertheless the dose prescribed in some cases was either higher than permitted by hospital protocols, or was inappropriately high when restarting the infusion after recovery of an atypical fetal heart rate pattern.
Interpretation of fetal heart rate tracing
In more than 70% of the cases reviewed, there was a delay in diagnosing an atypical or abnormal fetal heart rate pattern. In these instances, the most common issues were failure to appreciate and to act on the severity of an abnormal electronic fetal monitor tracing, or failure to apply a fetal scalp clip.
The physician-related issues pertaining to attendance were infrequent or irregular assessments of a patient with an atypical fetal heart rate pattern; not attending when informed by a nurse of concerns with the fetal heart rate tracing; reviewing only the immediate tracing record and thereby missing important abnormalities in the preceding time intervals; leaving the patient's bedside when the fetal heart rate tracing was worrisome; and failing to frequently assess a high-risk patient who was followed by a less experienced resident or staff member.
In more than half of the cases, the experts were of the opinion the physician failed to expedite delivery, usually by Caesarean section, when faced with an abnormal fetal tracing.
Communication and system-related factors contributed to the cases where there was a delay in performing a Caesarean delivery, including:
- the physician's attendance on another patient
- the physician's delay in answering repeated pages
- the lack of preparation to respond to an emergency in the situation
Very often, other factors contributed to the fetal harm in the other cases analyzed.
- communication problems between healthcare professionals about the following:
- atypical/abnormal fetal heart rate tracing
- dosage of oxytocin being infused
- frequency of oxytocin infusion increments
- transfer of care
- nursing interpretation of the fetal heart rate tracing
- inadequate monitoring of the fetal heart rate
- failure to act on concerning fetal heart rate changes following incremental dosing of oxytocin
- system-related problems
- failure to follow the hospital's protocols and guidelines for induction
- unavailability of resources, e.g. insufficient staff to monitor a patient on oxytocin
In several cases, peer experts identified inadequate documentation in the medical record as an issue for both physicians and nurses. Examples included an incomplete record of the delivery, and failure to document the time of chart entries. Expert comments also included that the use of milliunits per min provides better clarity on dosage, but if stating the flow rate of oxytocin in ml/min then the concentration of the infusion should also be stated.
A woman was admitted for induction at 37+5 weeks for oligohydramnios and an atypical non-stress test. Following two doses of dinoprostone, an oxytocin infusion was started. Electronic fetal monitoring remained normal at 145 bpm.
One hour later, the physician artificially ruptured the membranes for clear fluid and applied a scalp clip. Five hours after admission, an epidural was established. Within 30 minutes, the fetal heart rate tracing showed decreased variability and repetitive late decelerations. One hour later, the nurse noted increased uterine tone with poor relaxation between contractions; however, the nurse took no action and continued to increase the rate of oxytocin infusion.
Eight hours after admission, the nurse noted 3 late decelerations, minimal variability, and fetal tachycardia. The nurse advised the physician, who remotely reviewed the electronic fetal monitoring, but failed to assess the patient in person. The oxytocin infusion continued to be increased.
Nine hours after admission, the physician attended the patient and noted persistent minimal variability in the fetal heart rate tracing. The patient was fully dilated and instructions were given to start pushing. The monitor demonstrated late decelerations which progressively deepened; the physician was not notified. The oxytocin infusion continued to be increased. Two hours later, a limp infant was delivered spontaneously; aggressive resuscitation was required. The infant experienced early onset of convulsions and multi-system failure, and died 2 days later. The autopsy demonstrated extensive cerebral hypoxemic-ischemic changes.
A legal action was initiated, alleging the physician failed to act on the abnormal electronic fetal monitor tracing and proceed to an earlier Caesarean section.
The experts were of the opinion that both the physician and the nurse failed to intervene in a timely fashion and that a Caesarean delivery should have occurred 4 hours earlier.
Peer experts reviewing this case for the defence concluded that the adverse outcome could have been prevented if the physician had assessed the patient in person when the nurse expressed concern instead of remotely reviewing the electronic fetal monitor tracing
Without expert support, a shared settlement was paid by the CMPA, on behalf of the physician, and by the hospital, on behalf of the nurse.
Managing the risks of labour induction — Key learnings
The following risk management strategies are based on the expert opinions in the analyzed cases:
- Discuss with the patient the indication for induction as well as the risks and benefits.
- Document the informed consent discussion.
- Consider the experience of other healthcare professionals (e.g. nurses, residents) when monitoring obstetrical patients on oxytocin.
- Consider applying a fetal scalp electrode if the external monitoring is problematic or difficult to interpret.
- When presented with an abnormal tracing, review the clinical situation and determine if further testing or delivery is required.
- Assess the availability of resources to adequately monitor the patient and to respond to an emergency situation. Anticipate and perform, if indicated, a timely emergency Caesarean section.
- Communicate effectively with other healthcare professionals (e.g. consider the use of a structured communication tool2).
- Clearly and completely document the delivery in the medical record.
- In cases of adverse events, discuss the circumstances and outcomes with the patient and her family.
In addition, clear protocols for induction and administration of oxytocin should be in place at the facility, and all staff should be aware of these. Regular review for quality assurance is advised.
Members should not hesitate to contact the CMPA for risk management advice if they have questions related to this topic or need assistance with a complaint, legal action, or threat. Medical officers, physicians with extensive medico-legal experience, are available to guide and support members dealing with challenging medico-legal difficulties.
- Institute for Safe Medication Practices Canada [Internet]. ISMP's list of high-alert medications. © ISMP 2012. Available at: http://www.ismp.org/tools/highalertmedications.pdf. Last accessed May 17, 2012
- The CMPA does not endorse any specific structured communication approach or tool but encourages their use.