Pulse oximetry respiratory monitoring for assessment of acute childhood wheeze

OBJECTIVE

There is a lack of objective measures to assess children with acute wheezing episodes. Increased respiratory rate (RR) and pulsus paradoxus (PP) are recognised markers, but poorly recorded in practice. We examined whether they can be reliably assessed from a pulse oximeter plethysmogram ('pleth') trace and predict clinical outcome.

PATIENTS AND METHODS

We studied 44 children aged 1-7 years attending hospital with acute wheeze, following initial 'burst' bronchodilator therapy (BT), and used custom software to measure RR and assess PP from oximeter pleth traces. Traces were examined for quality, and the accuracy of the RR measurement was validated against simultaneous respiratory inductive plethysmography (RIP). RR and PP at 1 hour after BT were compared with clinical outcomes.

RESULTS

RR from pleth and RIP showed excellent agreement, with a mean difference (RIP minus pleth) of -0.5 breaths per minute (limits of agreement -3.4 to +2.3). 52% of 1 min epochs contained 10 s or more of pleth artefact. At 1 hour after BT, children who subsequently required intravenous bronchodilators had significantly higher RR (median (IQR) 63 (62-66) vs 43 (37-51) breaths per minute) than those who did not, but their heart rate and oxygen saturation were similar. Children with RR ≥55 per minute spent longer in hospital: median (IQR) 30 (22-45) vs 10 (7-21) hours. All children who subsequently required hospital admission had PP-analogous pleth waveforms 1 hour after BT.

CONCLUSION

RR can be reliably measured and PP detected from the pulse oximeter pleth trace in children with acute wheeze and both markers predict clinical outcome.

TRIAL REGISTRATION NUMBER

UKCRN15742.

Non-invasive sensor methods used in monitoring newborn babies after birth, a clinical perspective

Background

Reducing the global new-born mortality is a paramount challenge for humanity. There are approximately 786,323 live births in the UK each year according to the office for National Statistics; around 10% of these newborn infants require assistance during this transition after birth. Each year around, globally around 2.5 million newborns die within their first month. The main causes are complications due to prematurity and during delivery. To act in a timely manner and prevent further damage, health professionals should rely on accurate monitoring of the main vital signs heart rate and respiratory rate.

Aims

To present a clinical perspective on innovative, non-invasive methods to monitor heart rate and respiratory rate in babies highlighting their advantages and limitations in comparison with well-established methods.

Methods

Using the data collected in our recently published systematic review we highlight the barriers and facilitators for the novel sensor devices in obtaining reliable heart rate measurements. Details about difficulties related to the application of sensors and interfaces, time to display, and user feedback are explored. We also provide a unique overview of using a non-invasive respiratory rate monitoring method by extracting RR from the pulse oximetry trace of newborn babies.

Results

Novel sensors to monitor heart rate offer the advantages of minimally obtrusive technologies but have limitations due to movement artefact, bad sensor coupling, intermittent measurement, and poor-quality recordings compared to gold standard well established methods. Respiratory rate can be derived accurately from pleth recordings in infants.

Conclusion

Some limitations have been identified in current methods to monitor heart rate and respiratory rate in newborn babies. Novel minimally invasive sensors have advantages that may help clinical practice. Further research studies are needed to assess whether they are sufficiently accurate, practical, and reliable to be suitable for clinical use.

Characterisation of Textile Embedded Electrodes for Use in a Neonatal Smart Mattress Electrocardiography System

Heart rate monitoring is the predominant quantitative health indicator of a newborn in the delivery room. A rapid and accurate heart rate measurement is vital during the first minutes after birth. Clinical recommendations suggest that electrocardiogram (ECG) monitoring should be widely adopted in the neonatal intensive care unit to reduce infant mortality and improve long term health outcomes in births that require intervention. Novel non-contact electrocardiogram sensors can reduce the time from birth to heart rate reading as well as providing unobtrusive and continuous monitoring during intervention. In this work we report the design and development of a solution to provide high resolution, real time electrocardiogram data to the clinicians within the delivery room using non-contact electric potential sensors embedded in a neonatal intensive care unit mattress. A real-time high-resolution electrocardiogram acquisition solution based on a low power embedded system was developed and textile embedded electrodes were fabricated and characterised. Proof of concept tests were carried out on simulated and human cardiac signals, producing electrocardiograms suitable for the calculation of heart rate having an accuracy within ±1 beat per minute using a test ECG signal, ECG recordings from a human volunteer with a correlation coefficient of ~ 87% proved accurate beat to beat morphology reproduction of the waveform without morphological alterations and a time from application to heart rate display below 6 s. This provides evidence that flexible non-contact textile-based electrodes can be embedded in wearable devices for assisting births through heart rate monitoring and serves as a proof of concept for a complete neonate electrocardiogram monitoring system.

Strategies for implementing placental transfusion at birth: A systematic review

BACKGROUND

Enhanced placental transfusion reduces adverse neonatal outcomes, including death. Despite being endorsed by the World Health Organization in 2012, the method has not been adopted widely in practice.

METHODS

We performed a systematic literature search and included quality improvement projects on placental transfusion at birth and studies on barriers to implementation. We extracted information on population, methods of implementation, obstacles to implementation, and strategies to overcome them.

RESULTS

We screened 99 studies out of which 18 were included in the review. The preferred methods of implementation were protocol development (86% of studies) reinforced by targeted education (64% of studies) and multidisciplinary team involvement (43% of studies). Barriers to implementation were mentioned in 12 studies and divided into four categories: general factors such as lack of staff awareness (5 studies) and professional resistance to change (5 studies); obstetrician-specific concerns, including the impact during cesarean (3 studies) and the risk of postpartum hemorrhage (3 studies); pediatrician-specific concerns, including the need for resuscitation (5 studies), risk of jaundice (3 studies), and polycythemia (2 studies); and logistical difficulties. The main strategies to facilitate placental transfusion at birth included effective multidisciplinary team collaboration, protocol development, targeted education, and constructive feedback sessions.

CONCLUSIONS

Placental transfusion implementation requires a multidisciplinary approach, with obstetricians, midwives, nurses, and pediatricians central to adoption of the practice. Understanding the obstacles to implementation informs strategies to increase placental transfusion adoption of practice worldwide. We suggest a stepwise approach to implementation and enhancement of placental transfusion into practice.

Heart Rate Monitoring in Newborn Babies: A Systematic Review

BACKGROUND

Around 10% of newborn infants require assistance during transition after birth. Heart rate (HR) is the most important clinical indicator to evaluate the clinical status of a newborn.

AIM

Our study aimed to review all established and novel methods to detect HR in babies giving special consideration to non-invasive techniques.

METHODS

We performed a systematic literature search on the following databases: MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL. The inclusion criteria were studies on methods to detect HR in both term and preterm infants in comparison to one of the current gold standards: pulse oximetry (PO) or electrocardiography (ECG) published in the last 15 years. Two independent reviewers screened titles and abstracts for eligibility. Data extracted in an Excel table were analysed to produce a narrative review structured around the type of monitoring, identified obstacles in use, as well as methods to overcome these limitations.

RESULTS

The search revealed 649 studies after duplicates were removed. Full article analysis was performed on 26 studies of which 25 met the inclusion criteria. Well established methods such as auscultation and palpation, although rapid and easily available, have been shown to be inaccurate. ECG and PO were both more precise but the delay in obtaining a reliable HR signal from birth often exceeded 1-2 min. Novel sensors offered the advantages of minimally obtrusive technologies but have limitations mainly due to movement artefact, bad sensor coupling, intermittent measurement, and poor-quality recordings.

CONCLUSIONS

The limitations of existing methods have a potential impact on short- and long-term morbidity and mortality outcomes. The development of a technological solution to determine HR accurately and quickly in babies at birth has immense implications for further research and can guide interventions, such as placental transfusion and resuscitation.

The combined role of intravenous contrast enhanced ultrasound (CEUS) and computed tomography (CT) in liver abscess diagnosis

BACKGROUND AND AIMS

Through this study, we intend to review the main aspects regarding the contrast enhanced ultrasound evaluation of liver abscesses, pursuing a comparative analysis between the medical literature and our own experience.

MATERIAL AND METHODS

From June 2008 until December 2010 we have evaluated in our department a consecutive series of 11 patients with liver abscesses (7 males, 63.63%) all between the ages of 45 and 74. All the patients displayed a clinical and biological picture leading to an inflammatory process. The imaging diagnosis was made after confronting the results of the contrast enhanced ultrasound with those of the computed tomography.

RESULTS

In 10 out of 11 patients that were part of the study, we have assessed 14 liver abscesses. A single patient showed spread lesions inside both liver lobes, and they were assessed as hepatic micro abscesses. Three of the patients showed multiple right lobe lesions, 7 patients showed single lesions and one patient showed disseminated lesions within both lobes. We examined six mature lesions, 4 lesions with incomplete necrosis and 4 immature lesions, with no necrosis. The particular aspect of mycotic microabscesses is mentioned at the conventional ultrasound and at the CEUS as well.

CONCLUSION

Various types of hepatic abscesses have different imaging findings, and typical CT and CEUS findings can suggest the diagnosis.

[Cataract surgery in Romania--2003]

AIM

to evaluate cataract surgery performed in Romania analyzing: --the number of cataract surgery performed in 2003; --the surgical technique used: intracapsular extraction, extracapsular extraction, phacoemulsification; --the number and type of intraocular lenses used; --the number of ophthalmologists that performed cataract surgery;

MATERIAL AND METHOD

--a questionnaire was sent to all ophthalmologists which do cataract surgery.

RESULTS

--38,000 surgeries for cataract were performed in 2003; --the surgical techniques used were : Phacoemulsification (18,000 cases), classic extracapsular extraction ( 19,000 cases) and intracapsular extraction (1000 cases); --28,500 rigid and 8,000 foldable intraocular lenses were implanted; - 223 ophthalmologists perform cataract surgery in Romania.