The pitfalls of Pitocin in induction and augmentation of labour: medical-legal considerations

In Ontario, the administration of oxytocin to patients before or during labour is prevalent. In the 2017-2018 fiscal year, 54% of all low-risk patients in this category received the medication.^[1]

Oxytocin is classified as a high-alert medication by the Institute for Safe Medication Practices Canada (ISMP Canada) as it bears a heightened risk of causing significant harm when used in error. The Safety Considerations identified by ISMP Canada are risk of maternal, fetal, and/or neonatal harm.^[2]

The medication’s prevalent use combined with its potential to cause significant harm if misused heightens its medical-legal significance. The high-risk nature of oxytocin and the devastating impact that mismanagement can cause to patients requires that vigilance be maintained in decision making around oxytocin administration.

What is Oxytocin?

Oxytocin is a hormone that binds to uterine receptors to produce contractions. It is naturally secreted during pregnancy to stimulate uterine contractions. Its synthetic version, brand name Pitocin or Syntocinon, is commonly used by medical professionals for labour induction (to start labour) and to augment labour (when the time between already commenced contractions is too long, the length of contractions is too short, or contractions are too weak). It has been used by medical professionals for more than 70 years.^[3]

The medication is administered to patients intravenously using a pump to control the infusion rate.

The uterus is decreasingly responsive to oxytocin with prolonged labour due to the saturation of receptors.^[4] The maximal effective dose of oxytocin to achieve adequate contractions in all women is different.^[5]

The goal of induction or augmentation is to effect uterine activity sufficient to produce cervical change and fetal descent, while avoiding development of a nonreassuring fetal status.^[6]

The associated risks

The risks associated with oxytocin use can be serious and life threatening. Particular risks to the baby include: heart rate changes; and shortage of oxygen delivery due to overly strong or too frequent contractions,^[7] which if left unabated can cause hypoxic ischemic encephalopathy, associated brain damage and consequential lifelong serious impairments.

Particular maternal risks include: increased labour pain; fast/irregular heart rate or changes in blood pressure; heavy bleeding or post-partum bleeding; strong contractions that are too long or too frequent; headache; nausea; vomiting; and rarely, a tear in the uterus requiring an emergency cesarean section.^[8] Notably, in the 2017-2018 fiscal year, 25.9% of all patients who received oxytocin had an unplanned ceasarean birth.^[9]

These significant risks are reflected in the Canadian Medical Protective Association (CMPA) and The Healthcare Insurance Reciprocal of Canada (HIROC) collaboratively identified high-risk areas of obstetrical practice based upon assessments of medical-legal cases from 2004-2013. Induction and augmentation of labour with oxytocin were identified as the highest-risk area for physicians and the second highest-risk area for HIROC-insured hospitals. The closely related area of intrapartum fetal surveillance was identified as the second highest-risk area for physicians and the highest-risk area for HIROC-insured healthcare organizations. As intrapartum fetal surveillance is an integral component of oxytocin management, these findings highlight the substantial risks associated with both oxytocin administration and the assessment of fetal well-being during labour.^[10]

Team and practitioner loss of situational awareness and the misinterpretation of the fetal status are common contributing factors in oxytocin-related legal cases.^[11]

Usage guidelines and procedures

In Ontario, there are no provincial mandates for starting dose, nor dosing increments with respect to either time or concentration.^[12]

Both “high-dose” and “low-dose” regimens are referenced in guidelines and authoritative texts. The Provincial Council for Maternal and Child Health recommends that hospitals implement a low-dose regimen.^[13] The Society of Obstetricians and Gynecologists of Canada (SOGC), in its recommendations, states that “[a] local institutional protocol for oxytocin use with a safety checklist is required, regardless of infusion rate.”^[14]

The SOGC also recommends electronic fetal monitoring when using oxytocin for induction of labour.^[15] This is due to the risk of uterine tachysystole with fetal heart rate changes. Additionally, the ideal dosing regimen should be individualized and titrated to uterine activity, which makes an accurate uterine activity assessment essential.^[16]

The general goal of fetal health surveillance in labour is to detect potential fetal decompensation and to allow timely and effective interventions to prevent perinatal/neonatal morbidity and mortality.^[17] Fetal heart rate changes often precede brain injury and can act as a marker for fetal oxygenation and physiological change. Fetal heart rate characteristics are determined by assessing the fetal heart rate pattern in association with the uterine activity over time to develop a comprehensive clinical picture.^[18]

Systematic assessment of fetal heart rate, classification, and clear communication and complete documentation are imperative.^[19]

In general, oxytocin should be discontinued in the presence of tachysystole (number of contractions persists with a frequency of more than five in a 10-minute period or more than seven in a 15-minute period) or with a persistent nonreassuring fetal heart rate pattern. Once oxytocin is discontinued, contraction frequency nearly always rapidly decreases.^[20]

Oxytocin related legal cases, published case studies, and our firm’s experience

Reflecting CMPA and HIROC findings that labour induction and augmentation with oxytocin are among the highest-risk areas of obstetrical practice, alleged deficiencies in oxytocin administration and fetal heart rate monitoring are recurring issues in medical negligence.

In Crawford v. Penney,^[21] the defendant was found to have breached the standard of care by failing to stop the injection of oxytocin after normal contractions began and, as well, after shoulder dystocia was discovered.^[22] The plaintiff in this case suffered a permanent and disabling brain injury due to oxygen deprivation during delivery.

In Gilmore v. Love,^[23] the defendants breached the standard of care when they continued the administration of oxytocin after a cesarean section had been ordered; its administration ought to have been promptly discontinued once a cesarean delivery had been ordered.^[24] The trial judge determined that 90 minutes of additional pushing without progress, augmented by oxytocin for approximately 45 minutes was causative of the plaintiff’s injuries.^[25] The Plaintiff suffered extensive brain damage.^[26]

In College of Nurses of Ontario v. Dyer,^[27] the Discipline Committee of the College of Nurses of Ontario determined that the attending nurse restarted the administration of oxytocin at a particular rate without a physician order, increased the administration of oxytocin without a physician order and when it was not clinically appropriate to do so (the patient was in adequate labour and the fetus was experiencing fetal heart rate decelerations with each contraction). The fetus in this case was born by emergency cesarean section and sadly passed away the day of delivery.

In Case Study 1,^[28] HIROC summarized a situation where medical experts were critical of the attending nurse’s decision to increase the rate of oxytocin infusion to a rate higher than prescribed by hospital protocol, delays in stopping the infusion and notifying the most responsible physician in the context of tachysystole. Additionally, experts were critical of the physician’s decision to order augmentation as well as the nurse’s decision to accept the order and increase the rate of infusion in the context of strong and frequently occurring contractions.  The condition of the baby following delivery was not reported.

In Case Study 2,^[29] HIROC summarized a situation in which oxytocin infusion as continued in the context of minimal fetal heart rate variability and fetal heart rate decelerations. Medical experts were not supportive of the nurse’s decision to continue oxytocin, hesitancy to challenge or escalate concerns surrounding the physician’s order to continue with augmentation in the presence of ongoing abnormal fetal heart rate patterns and questioned whether the nurse “blindly followed” orders. The baby sustained permanent neurological sequalae.

In another Case Study,^[30] HIROC reported a situation where experts were critical of the attending nurse’s failure to discontinue an oxytocin infusion, commence intrauterine resuscitation and obtain immediate medical assistance in the context of ongoing abnormal fetal heart rate patterns. Experts also questioned the nurse’s clinical assessment skills, noting that the nurse’s documented interpretation of the fetal heart rate was inconsistent and unresponsive to concerning trends. Within 24 hours of birth, the baby was transferred to a pediatric facility with a tentative diagnosis of borderline prematurity, possible sepsis, apneic spells, episodic bradycardia, neonatal seizures and severe hypoxic ischemic encephalopathy.

In an additional Case Study,^[31] HIROC reported a situation where experts were critical of the nurse’s failure to discontinue the oxytocin administration following the identification of abnormal fetal heart rate patterns. Experts were also critical of the nurse’s failure to follow physician order requiring that oxytocin be discontinued once pushing commenced. Experts questioned whether the nurses relayed the degree of urgency necessary when communicating the fetal status to the responsible physician. The baby was diagnosed with severe hypoxic ischemic encephalopathy and transferred to a pediatric care facility.

The above-mentioned cases and case studies accord with our own experience in representing patients in obstetrical related medical negligence cases.

Prevalent themes of alleged negligence in our prosecuted cases include failure to appreciate the presence of atypical or abnormal fetal heart rate patterns and therefore failing to reduce or cease the infusion of oxytocin; failing to appreciate the occurrence of tachysystole and therefore failing to reduce or cease the infusion of oxytocin; increasing the infusion rate of oxytocin despite the fact that a favourable contraction pattern had been achieved; and administering oxytocin when contraindicated by the clinical circumstances.

In all the above situations, the fetus suffered life-long devastating brain injuries resulting in extensive care needs. Vigilance in the management of oxytocin administration that is responsive to the serious risks that can materialize with its misuse is required.

This article was provided by Neinstein LLP