Enhanced Neonatal Pulse Oximetry Sounds for the First Minutes of Life: A Laboratory Trial.

OBJECTIVE: Auditory enhancements to the pulse oximetry tone may help clinicians detect deviations from target ranges for oxygen saturation (SpO2) and heart rate (HR). BACKGROUND: Clinical guidelines recommend target ranges for SpO2 and HR during neonatal resuscitation in the first 10 minutes after birth. The pulse oximeter currently maps HR to tone rate, and SpO2 to tone pitch. However, deviations from target ranges for SpO2 and HR are not easy to detect. METHOD: Forty-one participants were presented with 30-second simulated scenarios of an infant's SpO2 and HR levels in the first minutes after birth. Tremolo marked distinct HR ranges and formants marked distinct SpO2 ranges. Participants were randomly allocated to conditions: (a) No Enhancement control, (b) Enhanced HR Only, (c) Enhanced SpO2 Only, and (d) Enhanced Both. RESULTS: Participants in the Enhanced HR Only and Enhanced SpO2 Only conditions identified HR and SpO2 ranges, respectively, more accurately than participants in the No Enhancement condition, ps < 0.001. In the Enhanced Both condition, the tremolo enhancement of HR did not affect participants' ability to identify SpO2 range, but the formants enhancement of SpO2 may have attenuated participants' ability to identify tremolo-enhanced HR range. CONCLUSION: Tremolo and formant enhancements improve range identification for HR and SpO2, respectively, and could improve clinicians' ability to identify SpO2 and HR ranges in the first minutes after birth. APPLICATION: Enhancements to the pulse oximeter tone to indicate clinically important ranges could improve the management of oxygen delivery to the neonate during resuscitation in the first 10 minutes after birth.

Similarity of expert clinicians' rank order of differential diagnoses in a newborn resuscitation context.

Background: We tested principles that could lead to a future cognitive aid that offers an interpretation of the newborn's physiological state during resuscitation after birth. Using concordance among experts' interpretations of newborn vital sign patterns as an approximation for an algorithm that could provide an interpretation of the newborn's state, we explored the reliability and generalisability of experts' interpretations. Methods: Twelve neonatal experts viewed eight pairs of graphical trajectories showing newborns' heart rate and oxygen saturation records supplemented with differential diagnoses elicited previously from other experts. Each pair of trajectories included one trajectory on which the original differential diagnoses had been based, and a similar but novel trajectory to which the original differential diagnoses were now generalised. For each trajectory, experts ranked the differential diagnoses according to their likelihood. We calculated how similar the new experts' ranking was to the original experts' ranking for both original and novel trajectories. We used descriptive categories to interpret the strength of the similarity. Results: For the original and novel trajectories, the experts' rank ordering of differential diagnoses was mostly moderately to substantially similar to the original rank ordering by the original participants. There were mostly small differences in similarity scores between the paired original and novel trajectories; fewer than 25% of the participants suggested an alternative differential diagnosis. Conclusions: The concordance of experts' interpretations could serve as an approximation of the newborn's physiological state, and the interpretations could be generalised. The results may justify pursuing an algorithm to underpin a cognitive aid.

Signaling Patient Oxygen Desaturation with Enhanced Pulse Oximetry Tones.

Manufacturers could improve the pulse tones emitted by pulse oximeters to support more accurate identification of a patient's peripheral oxygen saturation (SpO2) range. In this article, we outline the strengths and limitations of the variable-pitch tone that represents SpO2 of each detected pulse, and we argue that enhancements to the tone to demarcate clinically relevant ranges are feasible and desirable. The variable-pitch tone is an appreciated and trusted feature of the pulse oximeter's user interface. However, studies show that it supports relative judgments of SpO2 trends over time and is less effective at supporting absolute judgments about the SpO2 number or conveying when SpO2 moves into clinically important ranges. We outline recent studies that tested whether acoustic enhancements to the current tone could convey clinically important ranges more directly, without necessarily using auditory alarms. The studies cover the use of enhanced variable-pitch pulse oximeter tones for neonatal and adult use. Compared with current tones, the characteristics of the enhanced tones represent improvements that are both clinically relevant and statistically significant. We outline the benefits of enhanced tones, as well as discuss constraints of which developers of enhanced tones should be aware if enhancements are to be successful.

Concordance of expert clinicians' interpretations of the newborn's true physiological state.

BACKGROUND: Many physiological aspects of the neonatal transition after birth are unobservable because relevant sensors do not yet exist, compromising clinicians' understanding of a neonate's physiological status. Given that a neonate's true physiological state is currently unavailable, we explored the feasibility of using clinicians' degree of concordance as an approximation of the true physiological state. METHODS: Two phases of structured interviews were conducted. In Phase 1 (N = 8) and Phase 2 (N = 12), we presented neonatal experts with eight graphical trajectories of real newborns' heart rate and oxygen saturation values in the first 10-15 min after birth. We elicited the participants' interpretations of potential underlying physiological conditions that could explain the vital sign patterns. RESULTS: The global differential diagnosis data for each phase produced the same pattern of results: (1) four trajectories produced a substantial degree of concordance among clinicians (61-80%) and (2) four trajectories produced a strong degree of concordance among clinicians (81-100%). CONCLUSIONS: It is possible to achieve a strong degree of concordance among neonatal experts' interpretations of newborn trajectories. Thus, using the degree of concordance as an approximation of the neonate's true physiological state in resuscitation after birth may be a promising direction to explore for cognitive aid design. IMPACT: Differential diagnoses with a good degree of concordance among expert neonatal clinicians could potentially substitute in part for the direct measurement of key physiological and anatomical variables of the neonatal transition, which is currently unavailable. The concordance of clinicians' judgements or inferences with regards to the true physiological state of the newborn during resuscitation after birth has never been explored. The findings provide a crucial first step toward using consensus of neonatal experts' judgements in the design of a cognitive aid to support clinicians' management of the newborns who require resuscitation after birth.

Defining information needs in neonatal resuscitation with work domain analysis.

OBJECTIVE: To gain a deeper understanding of the information requirements of clinicians conducting neonatal resuscitation in the first 10 min after birth. BACKGROUND: During the resuscitation of a newborn infant in the first minutes after birth, clinicians must monitor crucial physiological adjustments that are relatively unobservable, unpredictable, and highly variable. Clinicians' access to information regarding the physiological status of the infant is also crucial to determining which interventions are most appropriate. To design displays to support clinicians during newborn resuscitation, we must first carefully consider the information requirements. METHODS: We conducted a work domain analysis (WDA) for the neonatal transition in the first 10 min after birth. We split the work domain into two 'subdomains'; the physiology of the neonatal transition, and the clinical resources supporting the neonatal transition. A WDA can reveal information requirements that are not yet supported by resources. RESULTS: The physiological WDA acted as a conceptual tool to model the exact processes and functions that clinicians must monitor and potentially support during the neonatal transition. Importantly, the clinical resources WDA revealed several capabilities and limitations of the physical objects in the work domain-ultimately revealing which physiological functions currently have no existing sensor to provide clinicians with information regarding their status. CONCLUSION: We propose two potential approaches to improving the clinician's information environment: (1) developing new sensors for the information we lack, and (2) employing principles of ecological interface design to present currently available information to the clinician in a more effective way.

A Novel Auditory Display for Neonatal Resuscitation: Laboratory Studies Simulating Pulse Oximetry in the First 10 Minutes After Birth.

OBJECTIVE: We tested whether enhanced sonifications would improve participants' ability to judge the oxygen saturation levels (SpO2) of simulated neonates in the first 10 min after birth. BACKGROUND: During the resuscitation of a newborn infant, clinicians must keep the neonate's SpO2 levels within the target range, however the boundaries for the target range change each minute during the first 10 min after birth. Resuscitation places significant demand on the clinician's visual attention, and the pulse oximeter's sonification could provide eyes-free monitoring. However, clinicians have difficulty judging SpO2 levels using the current sonification. METHOD: In two experiments, nonclinicians' ability to detect SpO2 range and direction-while performing continuous arithmetic problems-was tested with enhanced versus conventional sonifications. In Experiment 1, tremolo signaled when SpO2 had deviated below or above the target range. In Experiment 2, tremolo plus brightness signaled when SpO2 was above target range, and tremolo alone when SpO2 was below target range. RESULTS: The tremolo sonification improved range identification accuracy over the conventional display (81% vs. 63%, p < .001). The tremolo plus brightness sonification further improved range identification accuracy over the conventional display (92% vs. 62%, p <.001). In both experiments, there was no difference across conditions in arithmetic task accuracy ( p >.05). CONCLUSION: Using the enhanced sonifications, participants identified SpO2 range more accurately despite a continuous distractor task. APPLICATION: An enhanced pulse oximetry sonification could help clinicians multitask more effectively during neonatal resuscitations.