Electroencephalographic indices for clinical endpoints during propofol anesthesia in infants-an early phase propofol biomarker-finding study.

BACKGROUND: Unlike expired sevoflurane concentration, propofol lacks a biomarker for its brain effect site concentration (Ce), leading to dosing imprecision particularly in infants. Electroencephalography (EEG) monitoring can serve as a biomarker for propofol Ce, yet proprietary EEG indices are not validated in infants. We evaluated spectral edge frequency (SEF95) as a propofol anesthesia biomarker in infants. We hypothesized that the SEF95 targets will vary for different clinical stimuli and an inverse relationship existed between SEF95 and propofol plasma concentration. METHODS: This prospective study enrolled infants (3-12 months) to determine the SEF95 ranges for three clinical endpoints of anesthesia (consciousness-pacifier placement, pain-electrical nerve stimulation, and intubation-laryngoscopy) and correlation between SEF95 and propofol plasma concentration at steady state. Dixon's Up-Down method was used to determine target SEF95 for each clinical endpoint. Centered isotonic regression determined the dose-response function of SEF95 where 50% and 90% of infants (ED50 and ED90) did not respond to the clinical endpoint. Linear mixed-effect model determined the association of propofol plasma concentration and SEF95. RESULTS: Of 49 enrolled infants, 44 evaluable (90%) showed distinct SEF95 for endpoints: pacifier (ED50 21.4Hz, ED90 19.3Hz), electrical stimulation (ED50 12.6Hz, ED90 10.4Hz), and laryngoscopy (ED50 8.5Hz, ED90 5.2Hz). From propofol 0.5-6 µg/ml, a 1 Hz SEF95 increase was linearly correlated to a 0.24 (95% CI: 0.19 - 0.29, p<0.001) µg/mL decrease in plasma propofol concentration (marginal R 2 = 0.55). CONCLUSIONS: SEF95 can be a biomarker for propofol anesthesia depth in infants, potentially improving dosing accuracy and utilization of propofol anesthesia in this population.

Implementation of an electroencephalogram-guided propofol anesthesia practice in a large academic pediatric hospital: A quality improvement project.

BACKGROUND: Propofol-based total intravenous anesthesia is gaining popularity in pediatric anesthesia. Electroencephalogram can be used to guide propofol dosing to the individual patient to mitigate against overdosing and adverse events. However, electroencephalogram interpretation and propofol pharmacokinetics are not sufficiently taught in training programs to confidently deploy electroencephalogram-guided total intravenous anesthesia. AIMS: We conducted a quality improvement project with the smart aim of increasing the percentage of electroencephalogram-guided total intravenous anesthesia cases in our main operating room from 0% to 80% over 18 months. Balancing measures were number of total intravenous anesthesia cases, emergence times, and perioperative emergency activations. METHODS: The project key drivers were education, equipment, and electronic health record modifications. Plan-Do-Study-Act cycles included: (1) providing journal articles, didactic lectures, intraoperative training, and teaching documents; (2) scheduling electroencephalogram-guided total intravenous anesthesia teachers to train faculty, staff, and fellows for specific cases and to assess case-based knowledge; (3) adding age-based propofol dosing tables and electroencephalogram parameters to the electronic health record (EPIC co, Verona, WI); (4) procuring electroencephalogram monitors (Sedline, Masimo Inc). Electroencephalogram-guided total intravenous anesthesia cases and balancing measures were identified from the electronic health record. The smart aim was evaluated by statistical process control chart. RESULTS: After the four Plan-Do-Study-Act cycles, electroencephalogram-guided total intravenous anesthesia increased from 5% to 75% and was sustained at 72% 9 months after project completion. Total intravenous anesthesia cases/mo and number of perioperative emergency activations did not change significantly from start to end of the project, while emergence time for electroencephalogram-guided total intravenous anesthesia was greater statistically but not clinically (total intravenous anesthesia without electroencephalogram [16 ± 10 min], total intravenous anesthesia with electroencephalogram [18 ± 9 min], sevoflurane [17 ± 9 min] p < .001). CONCLUSION: Quality improvement methods may be deployed to adopt electroencephalogram-guided total intravenous anesthesia in a large academic pediatric anesthesia practice. Keys to success include education, in operating room case training, scheduling teachers with learners, electronic health record modifications, and electroencephalogram devices and supplies.

Intraoperative Ultrasound-Guided Transversus Abdominis Plane Catheters Placed for Post-operative Analgesia Following Pedicled Transverse Rectus Abdominis Myocutaneous Flap Breast Reconstruction: A Case Report.

Transverse rectus abdominis (TRAM) flap reconstruction of the breast is a procedure in which a flap of skin, fat, and underlying rectus abdominis muscle is used to reconstruct the breast. This procedure is commonly performed after mastectomy and results in significant pain at the donor abdominal site. We present this case of a 50-year-old female undergoing pedicled TRAM flap surgery in which ultrasound-guided transversus abdominis plane (TAP) catheters were placed intraoperatively, in a novel fashion: under ultrasound guidance, directly on the abdominal musculature, without overlying fat, subcutaneous tissue, or dressing. Our case-reported numeric pain scores ranged from 0-5/10 during postoperative days one to two. The patient's IV morphine requirement on postoperative days zero to two ranged between 1.34 mg to 2.6 mg per day, representing a significant decrease compared to literature-reported opioid consumption after such surgery. Her pain and opioid consumption increased significantly after catheter removal, suggesting the efficacy of our intraoperative TAP catheters.

Implementation of an electroencephalogram-guided propofol anesthesia education program in an academic pediatric anesthesia practice.

BACKGROUND: Propofol total intravenous anesthesia (TIVA) is increasingly popular in pediatric anesthesia, but education on its use is variable and over-dosage adverse events are not uncommon. Recent work suggests that electroencephalogram (EEG) parameters can guide propofol dosing in the pediatric population. This education quality improvement project aimed to implement a standardized EEG TIVA training program over 12 months in a large pediatric anesthesia division. METHODS: The division consisted of 63 faculty, 11 clinical fellows, 32 residents, and 28 nurse anesthetists at the Children's Hospital of Philadelphia. The program was assessed for effectiveness (a significant improvement in EEG knowledge scores), scalability (training 50% of fellows and staff), and sustainability (recurring EEG lectures for 80% of rotating residents and 100% of new fellows and staff). The key drivers included educational content development (lectures, articles, and hand-outs), training a cohort of EEG TIVA trainers, intraoperative teaching (teaching points and dosing tables), decision support tools (algorithms and anesthesia electronic record pop-ups), and knowledge tests (written exam and verbal quiz during cases). RESULTS: Over 12 months, 78.5% of the division (62/79) completed EEG training and test scores improved (mean score 38% before training vs 59% after training, p < .001). Didactic lectures were given to 100% of the fellows, 100% (11/11) of new staff, and 80% (4/5 blocks) of rotating residents. CONCLUSION: This quality improvement education project successfully trained pediatric anesthesia faculty, staff, residents, and fellows in EEG-guided TIVA. The training program was effective, scalable, and sustainable over time for newly hired faculty staff and rotating fellows and residents.