Adrienne Newburg

Microstream Capnography Improves Patient Monitoring During Moderate Sedation: A Randomized, Controlled Trial

BACKGROUND. Investigative efforts to improve monitoring during sedation for patients of all ages are part of a national agenda for patient safety. According to the Institute of Medicine, recent technological advances in patient monitoring have contributed to substantially decreased mortality for people receiving general anesthesia in operating room settings. Patient safety has not been similarly targeted for the several million children annually in the United States who receive moderate sedation without endotracheal intubation. Critical event analyses have documented that hypoxemia secondary to depressed respiratory activity is a principal risk factor for near misses and death in this population. Current guidelines for monitoring patient safety during moderate sedation in children call for continuous pulse oximetry and visual assessment, which may not detect alveolar hypoventilation until arterial oxygen desaturation has occurred. Microstream capnography may provide an “early warning system” by generating real-time waveforms of respiratory activity in nonintubated patients. OBJECTIVE. The aim of this study was to determine whether intervention based on capnography indications of alveolar hypoventilation reduces the incidence of arterial oxygen desaturation in nonintubated children receiving moderate sedation for nonsurgical procedures. PARTICIPANTS AND METHODS. We included 163 children undergoing 174 elective gastrointestinal procedures with moderate sedation in a pediatric endoscopy unit in a randomized, controlled trial. All of the patients received routine care, including 2-L supplemental oxygen via nasal cannula. Investigators, patients, and endoscopy staff were blinded to additional capnography monitoring. In the intervention arm, trained independent observers signaled to clinical staff if capnograms indicated alveolar hypoventilation for >15 seconds. In the control arm, observers signaled if capnograms indicated alveolar hypoventilation for >60 seconds. Endoscopy nurses responded to signals in both arms by encouraging patients to breathe deeply, even if routine patient monitoring did not indicate a change in respiratory status. OUTCOME MEASURES. Our primary outcome measure was patient arterial oxygen desaturation defined as a pulse oximetry reading of <95% for >5 seconds. Secondary outcome measures included documented assessments of abnormal ventilation, termination of the procedure secondary to concerns for patient safety, as well as other more rare adverse events including need for bag-mask ventilation, sedation reversal, or seizures. RESULTS. Children randomly assigned to the intervention arm were significantly less likely to experience arterial oxygen desaturation than children in the control arm. Two study patients had documented adverse events, with no procedures terminated for patient safety concerns. Intervention and control patients did not differ in baseline characteristics. Endoscopy staff documented poor ventilation in 3% of all procedures and no apnea. Capnography indicated alveolar hypoventilation during 56% of procedures and apnea during 24%. We found no change in magnitude or statistical significance of the intervention effect when we adjusted the analysis for age, sedative dose, or other covariates. CONCLUSIONS. The results of this controlled effectiveness trial support routine use of microstream capnography to detect alveolar hypoventilation and reduce hypoxemia during procedural sedation in children. In addition, capnography allowed early detection of arterial oxygen desaturation because of alveolar hypoventilation in the presence of supplemental oxygen. The current standard of care for monitoring all patients receiving sedation relies overtly on pulse oximetry, which does not measure ventilation. Most medical societies and regulatory organizations consider moderate sedation to be safe but also acknowledge serious associated risks, including suboptimal ventilation, airway obstruction, apnea, hypoxemia, hypoxia, and cardiopulmonary arrest. The results of this controlled trial suggest that microstream capnography improves the current standard of care for monitoring sedated children by allowing early detection of respiratory compromise, prompting intervention to minimize hypoxemia. Integrating capnography into patient monitoring protocols may ultimately improve the safety of nonintubated patients receiving moderate sedation.

Efficiency of propofol versus midazolam and fentanyl sedation at a pediatric teaching hospital : a prospective study

BACKGROUND Many pediatric endoscopists are adopting propofol in their practices, with the expectation that propofol will increase their overall efficiency. OBJECTIVE AND SETTING To compare the efficiency of propofol versus midazolam and fentanyl by measuring elapsed times between initial intravenous administration and patient discharge at a pediatric teaching hospital. DESIGN Endoscopy times were prospectively collected for consecutive patients who were undergoing either anesthesiologist-administered propofol or endoscopist-administered midazolam and fentanyl. The effect of the type of sedation on these times was assessed by using multiple linear regression by adjusting for other candidate predictors, including concomitant use of other sedatives, endotracheal intubation by anesthesiologists, and the presence of fellow trainees. MAIN OUTCOME MEASUREMENTS Time to onset of sedation (time sedation started to scope in), procedure time (endoscope in to endoscope out), discharge time (endoscope out to hospital discharge), and total time (sedation started to hospital discharge). RESULTS The times for 134 children (mean age 12 +/- 5 years) to receive propofol sedation were compared with those of 195 children (13 +/- 5 years) who received midazolam and fentanyl. Midazolam and fentanyl cases disproportionately included EGDs (P < .001) and patients who were classified as American Society of Anesthesiologists I (P < .03). Patients who received propofol had shorter times until sedated, similar procedure times, longer discharge times, and comparable total times. Multivariate analyses confirmed that fellow participation prolonged the procedure times (P < .0001), and endotracheal intubation prolonged propofol times (P <. 01), but adjusting for these did not change the comparison results. CONCLUSIONS Anesthesiologist-administered propofol sedation in a pediatric teaching endoscopy unit may not lead to faster hospital times when compared with endoscopist-administered midazolam and fentanyl. These results are not explained by controlling for patient characteristics, the presence of a trainee, the sedative doses, or endotracheal intubation for airway management.

Fellow perceptions of training using computer-based endoscopy simulators

BACKGROUND Integrating procedural training by using computer-based endoscopic simulators (CBES) into gastroenterology fellowships may facilitate technical skill development, while posing no additional risk to patients. OBJECTIVE The aim of our study was to survey pediatric gastroenterology fellows about their experiences with and perceptions of CBES as compared with actual procedures, prior to and after exposure to both types of endoscopic learning. DESIGN AND SETTING All first-year trainees at Childrens Hospital Boston (2003-2008) were invited to complete a written, pretraining questionnaire and then perform at least 10 each of CBES endoscopies and colonoscopies prior to performing actual procedures. Fellows completed a written, posttraining questionnaire after 4 months. MAIN OUTCOME MEASUREMENTS Survey responses. RESULTS All 25 first-year fellows (12 male, median age 30 years) over the 5-year period participated. Four months into their fellowships, fellows reported simulation to be helpful in increasing procedural skill and confidence. The number of sessions on the simulator was associated with reported increased colonoscopic skill and confidence (P = .032 and P = .007, respectively). All fellows reported it difficult to incorporate CBES into their work schedules. Only 28% of fellows reported performing 20 total CBES procedures, with most simulation sessions reportedly lasting less than 30 minutes. All participants rated faculty instruction with CBES as very helpful. LIMITATIONS This was a single-site study of pediatric trainees and may be limited in generalizability. CONCLUSION A few short sessions with CBES may be perceived as useful for endoscopic skill acquisition by pediatric gastroenterology trainees. Further exploration into how to assimilate CBES into busy gastroenterology training programs may be warranted.

A Randomized Double-Blind Controlled Trial of Microstream Capnography to Reduce Oxygen Desaturation During Gastrointestinal Procedures with Conscious Sedation

A Randomized Double-Blind Controlled Trial of Microstream Capnography to Reduce Oxygen Desaturation During Gastrointestinal Procedures with Conscious Sedation Jenifer Lightdale, Henry Feldman, Adrienne Newburg, Victoria Turbini, Lisa Heard, Kate Donovan, James DiNardo, Victor Fox Oxygen desaturation is a relatively late sign of ventilatory compromise. ASGE monitoring guidelines for all GI procedures call for continuous pulse oximetry and visual assessment during conscious sedation (CS), which may not detect apnea until O2 desaturation has occurred. Microstream capnography may provide an ‘‘early warning system’’ by generating real-time waveforms of respiration (capnograms) in non-intubated patients. Aim: To determine whether intervention based on capnography indications of apnea reduces O2 desaturation during CS. Methods: We performed an IRB-approved double-blind randomized controlled trial of ASA Class I/II children undergoing GI procedures with midazolam C fentanyl CS, 2L supplemental O2, standard patient monitoring, and routine care. Endoscopy staff was blinded to additional continuous capnography monitoring (Philips M4 with Microstream CO2). Study arm was determined by opening a pre-numbered sequence of envelopes containing randomly permuted assignments. In the intervention arm, a trained independent monitor (IM) signaled to the endoscopy staff by raised hand if capnograms indicated apnea for O15 sec. In the control arm, an IM signaled if capnograms indicated apnea for O60 sec. Upon IM signals, endoscopy RNs instructed patients to breathe deeply and/or touched their backs. We hypothesized that patients randomized to the intervention arm would have fewer episodes of minor O2 desaturation (O2 sats !95% for 5 sec) than patients in the control arm. Results: 163 participants (89 male; mean age 13 yr, range 6mo19 yr; 86% ASA I) underwent 174 procedures (80% EGD, 13% colonoscopy, 7% both). Intervention and control patients did not differ significantly in sex, age, ASA class, procedures undergone, baseline O2 sats, or doses of midazolam and fentanyl. Endoscopy RNs documented poor ventilation in 2.7% of study patients and no apnea. Capnography indicated disordered ventilation during 56% of all procedures and apnea in 24%. Patients in the intervention arm were significantly less likely to have an intraprocedural episode of O2 desaturation than those in the control arm (11% vs 24%, p ! 0.03). Conclusions: The results of this controlled effectiveness trial support the routine use of microstream capnography to improve detection of apnea and reduce O2 desaturation during CS for GI procedures. Supported by AHRQ (K08 HS1-367502), a Risk Management Foundation Patient Safety Grant and Children’s Hospital Boston GCRC (M01-RR02172).

Magnetic Resonance Imaging-Directed Ultrasound Imaging of Non-Mass Enhancement in the Breast: Outcomes and Frequency of Malignancy

This study was performed to determine the frequency, predictors, and outcomes of ultrasound (US) correlates for non‐mass enhancement.

Radiologic-Pathologic Discordance and Outcome After MRI-Guided Vacuum-Assisted Biopsy

OBJECTIVE The purpose of this study was to determine the rate, characteristics, and outcomes of discordant MRI-guided vacuum-assisted biopsy (VAB) in women with suspected breast cancer. MATERIALS AND METHODS This retrospective study reviewed 1314 MRI-guided VABs performed in 1211 women between 2007 and 2013 and yielded 25 discordant results in 24 women. MRI characteristics; BI-RADS assessments; whether the lesion was missed, partially sampled, or excised at biopsy; and biopsy and surgical pathology results were reviewed. Statistical analyses were performed using Fisher exact and Mann-Whitney U tests. RESULTS Among 1314 lesions that underwent MRI-guided VAB, 25 results were discordant (1.9%; 95% CI, 1.2-2.8%), and nine lesions with discordant results (36.0%, 95% CI, 18.5-56.9%) were malignant at surgical excision (three invasive ductal carcinoma and six ductal carcinoma in situ). There was no significant association between malignancy and lesion type, size, enhancement pattern, BI-RADS assessment, or clinical indication. Forty-four percent (11/25) of discordant lesions were missed, 48.0% (12/25) were partially sampled, and 8.0% (2/25) appeared to have been excised. Of the nine malignant lesions, 44.4% (4/9) discordant malignant lesions were missed, 44.4% (4/9) were partially sampled, and 11.1% (1/9) appeared to have been excised. Lesion sizes and types were similar in the missed and partially excised groups. CONCLUSION The potential for false-negative results at MRI-guided VAB underscores the importance of radiologic-histologic correlation and imaging review after biopsy. Rebiopsy or excision in discordant cases is therefore recommended.