Out of pocket costs and time/productivity losses for pediatric sepsis in Uganda: a mixed-methods study.

BACKGROUND: Sepsis disproportionately affects children from socioeconomically disadvantaged families in low-resource settings, where care seeking may consume scarce family resources and lead to financial hardships. Those financial hardships may, in turn, contribute to late presentation or failure to seek care and result in high mortality during hospitalization and during the post discharge period, a period of increasingly recognized vulnerability. The purpose of this study is to explore the out-of-pocket costs related to sepsis hospitalizations and post-discharge care among children admitted with sepsis in Uganda. METHODS: This mixed-methods study was comprised of focus group discussions (FGD) with caregivers of children admitted for sepsis, which then informed a quantitative cross-sectional household survey to measure out-of-pocket costs of sepsis care both during initial admission and during the post-discharge period. All participants were families of children enrolled in a concurrent sepsis study. RESULTS: Three FGD with mothers (n = 20) and one FGD with fathers (n = 7) were conducted. Three primary themes that emerged included (1) financial losses, (2) time and productivity losses and (3) coping with costs. A subsequently developed cross-sectional survey was completed for 153 households of children discharged following admission for sepsis. The survey revealed a high cost of care for families attending both private and public facilities, although out-of-pocket cost were higher at private facilities. Half of those surveyed reported loss of income during hospitalization and a third sold household assets, most often livestock, to cover costs. Total mean out-of-pocket costs of hospital care and post-discharge care were 124.50 USD and 44.60 USD respectively for those seeking initial care at private facilities and 62.10 USD and 14.60 USD at public facilities, a high sum in a country with widespread poverty. CONCLUSIONS: This study reveals that families incur a substantial economic burden in accessing care for children with sepsis.

Respiratory rates observed over 15 seconds compared with rates measured using the RRate app. Practice-based evidence from an observational study of acutely ill adult medical patients during their hospital admission.

BACKGROUND: counting respiratory rate over 60 seconds can be impractical in a busy clinical setting. METHODS: 870 respiratory rates of 272 acutely ill medical patients estimated from observations over 15 seconds and those calculated by a computer algorithm were compared. RESULTS: The bias of 15 seconds of observations was 1.85 breaths per minute and 0.11 breaths per minute for the algorithm derived rate, which took 16.2 SD 8.1 seconds. The algorithm assigned 88% of respiratory rates their correct National Early Warning Score points, compared with 80% for rates from 15 seconds of observation. CONCLUSION: The respiratory rates of acutely ill patients are measured nearly as quickly and more reliably by a computer algorithm than by observations over 15 seconds.

The effect of cardiac output on the pharmacokinetics and pharmacodynamics of propofol during closed-loop induction of anesthesia.

BACKGROUND AND OBJECTIVE: Intraoperative hemodynamic stability is essential to safety and post-operative well-being of patients and should be optimized in closed-loop control of anesthesia. Cardiovascular changes inducing variations in pharmacokinetics may require dose modification. Rigorous investigational tools can strengthen current knowledge of the anesthesiologists and support clinical practice. We quantify the cardiovascular response of high-risk patients to closed-loop anesthesia and propose a new application of physiologically-based pharmacokinetic-pharmacodynamic (PBPK-PD) simulations to examine the effect of hemodynamic changes on the depth of hypnosis (DoH). METHODS: We evaluate clinical hemodynamic changes in response to anesthesia induction in high-risk patients from a study on closed-loop anesthesia. We develop and validate a PBPK-PD model to simulate the effect of changes in cardiac output (CO) on plasma levels and DoH. The wavelet-based anesthetic value for central nervous system monitoring index (WAVCNS) is used as clinical end-point of propofol hypnotic effect. RESULTS: The median (interquartile range, IQR) changes in CO and arterial pressure (AP), 3 min after induction of anesthesia, are 22.43 (14.82-36.0) % and 26.60 (22.39-35.33) % respectively. The decrease in heart rate (HR) is less marked, i.e. 8.82 (4.94-12.68) %. The cardiovascular response is comparable or less enhanced than in manual propofol induction studies. PBPK simulations show that the marked decrease in CO coincides with high predicted plasma levels and deep levels of hypnosis, i.e. WAVCNS < 40. PD model identification is improved using the PBPK model rather than a standard three-compartment PK model. PD simulations reveal that a 30% drop in CO can cause a 30% change in WAVCNS. CONCLUSIONS: Significant CO drops produce increased predicted plasma concentrations corresponding to deeper anesthesia, which is potentially dangerous for elderly patients. PBPK-PD model simulations allow studying and quantifying these effects to improve clinical practice.

Respiratory rates observed over 15 and 30 s compared with rates measured over 60 s: practice-based evidence from an observational study of acutely ill adult medical patients during hospital admission.

BACKGROUND: Respiratory rate is often measured over a period shorter than 1 min and then multiplied to produce a rate per minute. There are few reports of the performance of such estimates compared with rates measured over a full minute. AIM: Compare performance of respiratory rates calculated from 15 and 30 s of observations with measurements over 1 min. DESIGN: A prospective single center observational study. METHODS: The respiratory rates calculated from observations for 15 and 30 s were compared with simultaneous respiratory rates measured for a full minute on acutely ill medical patients during their admission to a resource poor hospital in sub-Saharan Africa using a novel respiratory rate tap counting software app. RESULTS: There were 770 respiratory rates recorded on 321 patients while they were in the hospital. The bias (limits of agreement) between the rate derived from 15 s of observations and the full minute was -1.22 breaths per minute (bpm) (-7.16 to 4.72 bpm), and between the rate derived from 30 s and the full minute was -0.46 bpm (-3.89 to 2.97 bpm). Rates observed over 1 min that scored 3 National Early Warning Score points were not identified by half the rates derived from 15 s and a quarter of the rates derived from 30 s. CONCLUSION: Practice-based evidence shows that abnormal respiratory rates are more reliably detected with measurements made over a full minute, and respiratory rate measurement 'short-cuts' often fail to identify sick patients.

A smartphone oximeter with a fingertip probe for use during exercise training: usability, validity and reliability in individuals with chronic lung disease and healthy controls.

BACKGROUND AND AIM: Telehealth is a strategy to expand the reach of pulmonary rehabilitation (PR). Smartphones can monitor and transmit oxygen saturation (SpO2) and heart rate (HR) data to ensure patient safety during home-based or other exercise. The purpose of this study was to evaluate the usability, validity and reliability of a Kenek O2 pulse oximeter and custom prototype smartphone application (smartphone oximeter) during rest and exercise in healthy participants and those with chronic lung disease. METHODS: Fifteen individuals with chronic lung disease and 15 healthy controls were recruited. SpO2 and HR were evaluated at rest and during cycling and walking. SpO2 was valid if the mean bias was within +±2%, the level of agreement (LoA) was within ±4%; HR was valid if the mean bias was within ±5 beats per min (bpm), LoA was within ±10bpm. Usability was assessed with a questionnaire and direct observation. RESULTS: The smartphone oximeter was deemed easy to use. At rest, SpO2 measures were valid in both groups (bias <2%, lower bound LoA -2 to 3%). During exercise, SpO2 measurement did not meet validity and reliability thresholds in the patients with chronic lung disease, but was accurate for the healthy controls. HR recording during exercise or rest was not valid (LoA>10bpm) in either group. CONCLUSIONS: The smartphone oximeter did not record HR or SpO2 accurately in patients with chronic lung disease during exercise, although SpO2 was valid at rest. During exercise, patients with chronic lung disease should pause to ensure greatest accuracy of SpO2 and HR measurement.

Postdischarge mortality in children with acute infectious diseases: derivation of postdischarge mortality prediction models.

OBJECTIVES: To derive a model of paediatric postdischarge mortality following acute infectious illness. DESIGN: Prospective cohort study. SETTING: 2 hospitals in South-western Uganda. PARTICIPANTS: 1307 children of 6 months to 5 years of age were admitted with a proven or suspected infection. 1242 children were discharged alive and followed up 6 months following discharge. The 6-month follow-up rate was 98.3%. INTERVENTIONS: None. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was postdischarge mortality within 6 months following the initial hospital discharge. RESULTS: 64 children died during admission (5.0%) and 61 died within 6 months of discharge (4.9%). Of those who died following discharge, 31 (51%) occurred within the first 30 days. The final adjusted model for the prediction of postdischarge mortality included the variables mid-upper arm circumference (OR 0.95, 95% CI 0.94 to 0.97, per 1 mm increase), time since last hospitalisation (OR 0.76, 95% CI 0.61 to 0.93, for each increased period of no hospitalisation), oxygen saturation (OR 0.96, 95% CI 0.93 to 0·99, per 1% increase), abnormal Blantyre Coma Scale score (OR 2.39, 95% CI 1·18 to 4.83), and HIV-positive status (OR 2.98, 95% CI 1.36 to 6.53). This model produced a receiver operating characteristic curve with an area under the curve of 0.82. With sensitivity of 80%, our model had a specificity of 66%. Approximately 35% of children would be identified as high risk (11.1% mortality risk) and the remaining would be classified as low risk (1.4% mortality risk), in a similar cohort. CONCLUSIONS: Mortality following discharge is a poorly recognised contributor to child mortality. Identification of at-risk children is critical in developing postdischarge interventions. A simple prediction tool that uses 5 easily collected variables can be used to identify children at high risk of death after discharge. Improved discharge planning and care could be provided for high-risk children.

Changes in cardiac index and blood pressure on positioning children prone for scoliosis surgery.

In this prospective observational study we investigated the changes in cardiac index and mean arterial pressure in children when positioned prone for scoliosis correction surgery. Thirty children (ASA 1-2, aged 13-18 years) undergoing primary, idiopathic scoliosis repair were recruited. The cardiac index and mean arterial blood pressure (median (IQR [range])) were 2.7 (2.3-3.1 [1.4-3.7]) l.min(-1).m(-2) and 73 (66-80 [54-91]) mmHg, respectively, at baseline; 2.9 (2.5-3.2 [1.7-4.4]) l.min(-1).m(-2) and 73 (63-81 [51-96]) mmHg following a 5-ml.kg(-1) fluid bolus; and 2.5 (2.2-2.7 [1.4-4.8]) l.min(-1).m(-2) and 69 (62-73 [46-85]) mmHg immediately after turning prone. Turning prone resulted in a median reduction in cardiac index of 0.5 l.min(-1).m(-2) (95% CI 0.3-0.7 l.min(-1).m(-2), p=0.001), or 18.5%, with a large degree of inter-subject variability (+10.3% to -40.9%). The changes in mean arterial blood pressure were not significant. Strategies to predict, prevent and treat decreases in cardiac index need to be developed.

Photoplethysmogram signal quality estimation using repeated Gaussian filters and cross-correlation.

Pulse oximeters are monitors that noninvasively measure heart rate and blood oxygen saturation (SpO2). Unfortunately, pulse oximetry is prone to artifacts which negatively impact the accuracy of the measurement and can cause a significant number of false alarms. We have developed an algorithm to segment pulse oximetry signals into pulses and estimate the signal quality in real time. The algorithm iteratively calculates a signal quality index (SQI) ranging from 0 to 100. In the presence of artifacts and irregular signal morphology, the algorithm outputs a low SQI number. The pulse segmentation algorithm uses the derivative of the signal to find pulse slopes and an adaptive set of repeated Gaussian filters to select the correct slopes. Cross-correlation of consecutive pulse segments is used to estimate signal quality. Experimental results using two different benchmark data sets showed a good pulse detection rate with a sensitivity of 96.21% and a positive predictive value of 99.22%, which was equivalent to the available reference algorithm. The novel SQI algorithm was effective and produced significantly lower SQI values in the presence of artifacts compared to SQI values during clean signals. The SQI algorithm may help to guide untrained pulse oximeter users and also help in the design of advanced algorithms for generating smart alarms.

Usability testing of a prototype Phone Oximeter with healthcare providers in high- and low-medical resource environments.

To increase the use of pulse oximetry by capitalise on the wide availability of mobile phones, we have designed, developed and evaluated a prototype pulse oximeter interfaced to a mobile phone. Usability of this Phone Oximeter was tested as part of a rapid prototyping process. Phase 1 of the study (20 subjects) was performed in Canada. Users performed 23 tasks, while thinking aloud. Time for completion of tasks and analysis of user response to a mobile phone usability questionnaire were used to evaluate usability. Five interface improvements were made to the prototype before evaluation in Phase 2 (15 subjects) in Uganda. The lack of previous pulse oximetry experience and mobile phone use increased median (IQR [range]) time taken to perform tasks from 219 (160-247 [118-274]) s in Phase 1 to 228 (151-501 [111-2661]) s in Phase 2. User feedback was positive and overall usability high (Phase 1--82%, Phase 2--78%).

Pulse oximeter plethysmograph variation and its relationship to the arterial waveform in mechanically ventilated children.

The variations induced by mechanical ventilation in the arterial pulse pressure and pulse oximeter plethysmograph waveforms have been shown to correlate closely and be effective in adults as markers of volume responsiveness. The aims of our study were to investigate: (1) the feasibility of recording plethysmograph indices; and (2) the relationship between pulse pressure variation (ΔPP), plethysmograph variation (ΔPOP) and plethysmograph variability index (PVI) in a diverse group of mechanically ventilated children. A prospective, observational study was performed. Mechanically ventilated children less than 11 years of age, with arterial catheters, were enrolled during the course of their clinical care in the operating room or in the pediatric intensive care unit. Real time monitor waveforms and trend data were recorded. ΔPP and ΔPOP were manually calculated and the relationships between ΔPP, ΔPOP and PVI were compared using Bland-Altman analysis and Pearson correlations. Forty-nine children were recruited; four (8%) subjects were excluded due to poor quality of the plethysmograph waveforms. ΔPP and ΔPOP demonstrated a strong correlation (r = 0.8439, P < 0.0001) and close agreement (Bias = 1.44 ± 6.4%). PVI was found to correlate strongly with ΔPP (r = 0.7049, P < 0.0001) and ΔPOP (r = 0.715, P < 0.0001). This study demonstrates the feasibility of obtaining plethysmographic variability indices in children under various physiological stresses. These data show a similarly strong correlation to that described in adults, between the variations induced by mechanical ventilation in arterial pulse pressure and the pulse oximeter plethysmograph.

Time to listen: a review of methods to solicit patient reports of adverse events.

BACKGROUND: Patients have been shown to report accurate observations of medical errors and adverse events. Various methods of introducing patient reporting into patient safety systems have been published with little consensus among researchers on the most effective method. Terminology for use in patient safety reporting has yet to be standardised. METHODS: Two databases, PubMed and MEDLINE, were searched for literature on patient reporting of medical errors and adverse events. Comparisons were performed to identify the optimal method for eliciting patient initiated events. RESULTS: Seventeen journal publications were reviewed by patient population, type of healthcare setting, contact method, reporting method, duration, terminology and reported response rate. CONCLUSION: Few patient reporting studies have been published, and those identified in this review covered a wide range of methods in diverse settings. Definitive comparisons and conclusions are not possible. Patient reporting has been shown to be reliable. Higher incident rates were observed when open-ended questions were used and when respondents were asked about personal experiences in hospital and primary care. Future patient reporting systems will need a balance of closed-ended questions for cause analysis and classification, and open-ended narratives to allow for patient's limited understanding of terminology. Establishing the method of reporting that is most efficient in collecting reliable reports and standardising terminology for patient use should be the focus of future research.

Clinical evaluation of algorithms for context-sensitive physiological monitoring in children.

BACKGROUND: Subtle changes in monitored physiological signals might be used to guide clinical actions and give early warning of potential adverse events. Automated early warning systems could enhance the clinician's interpretation of data by instantaneously processing new information and presenting it within the context of previous observations. In this study, we tested algorithms for tracking the behaviour of dynamic physiological systems and automatically detecting key events over time. METHODS: Algorithms were activated in real-time during anaesthesia to run context-sensitive monitoring of six variables (end-tidal PCO(2), heart rate, exhaled minute ventilation, non-invasive arterial pressure, respiratory rate, and oxygen saturation), alongside standard physiological monitors. The clinical evaluation included real-time feedback on each change point (change in the physiological trend) detected by the algorithms and the completion of a usability questionnaire. RESULTS: Fifteen anaesthetists completed the evaluation during paediatric surgical cases. A total of 38 cases were evaluated, with a mean duration of 103 (102) min. The mean number of change points per case was 22.8 (23.4). Sixty-one per cent of all rated change points were considered clinically significant, and <7% were due to artifacts. CONCLUSIONS: The algorithms were able to detect a range of clinically significant physiological changes during paediatric anaesthesia, and were considered useful by participating anaesthetists. These findings indicate that automated detection of context-sensitive changes is possible and could be used by early warning systems during physiological monitoring. Further investigations are required to assess how this information can best be communicated to the anaesthetist.

What is SNOMED CT and why should the ISSHP care?

SNOMED CT (Systematized NOmenclature of MEDicine Clinical Terms) is a standardized multilingual healthcare terminology. It was developed to meet the needs of our electronic world so that care can be documented and clinicians can retrieve and transmit data in electronic format. It is anticipated that SNOMED CT will provide the core general terminology for electronic health records and, as such, replace existing classification systems such as the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10). At present, there is no special interest group for the hypertensive disorders of pregnancy (HDP) within the SNOMED CT initiative. We believe that members of the ISSHP, and others interested in the HDP, should take a leadership role in this regard for a number of reasons.

Accuracy of detecting changes in auditory heart rate in a simulated operating room environment.

The threshold for the identification of changes in heart rate and the accuracy in estimating heart rate were compared between 20 anaesthetists and 20 non-anaesthetists in a simulated operating theatre, both with and without distraction tasks. Typical operating theatre distractions were simulated by requiring anaesthetists and non-anaesthetists to perform secondary tasks. There were no differences found between the groups in identification of heart rate changes. The distraction tasks reduced performance in both groups (to a greater extent in the anaesthetists group). A change of > 10 beats per minute was required for 80% of the changes to be detected. An upward heart rate change was more easily detected than a reduction. Anaesthetists were found to be marginally better at estimating the heart rate change from an auditory tone alone. However, the study did not confirm that anaesthetists have a superior ability to detect changes in heart rate than non-anaesthetists.

Autonomic nervous system response to vibrating and electrical stimuli on the forearm and wrist.

In today's operating rooms, anesthesiologists use physiological data monitoring systems with visual and auditory cues to receive patient information. The efficacy of these visual-audio systems is limited by the human limitations of these modalities. Previous studies have shown the potential use of a complementary, or alternate, patient data monitoring technology utilizing another psychophysically relevant modality: the sense of touch via vibro-tactile or electro-tactile stimulation. In this paper, we describe an experiment designed to determine whether the specific type and/or location of such a tactile stimulation device on the arm affects the autonomic nervous system response. In our study, each of 10 participants tested a vibro-tactile display on the forearm (VF), a vibro-tactile display on the wrist (VW), and an electro-tactile display on the forearm (EF) in random order. Using the LifeShirt, system, electrocardiogram (ECG), respiratory rate (Br), tidal volume (Vt) data were collected. Results showed a higher value of the heart rate and heart rate variability (HRV) when using the VF compared to the VW and EF. We also found that the HRV response for the three tactile prototypes was correlated with the accuracy of tactile pattern identification.

Evaluations of tactile displays of physiological monitoring.

Physiological monitoring devices are used in the operating room (OR) to identify abnormal changes. They are currently detected by the anesthesiologist from direct observation of visual displays or by auditory cues. In an effort to improve OR safety, we explored the use of an alternative sensory modality, touch, to effectively and accurately convey patients' physiological information. To be accepted [1] such devices need to fulfill five criteria: learnability, errors, efficiency, memorability and satisfaction. We designed and compared various tactile displays in respect to some of these criteria.

Evaluation of a tactile display around the waist for physiological monitoring under different clinical workload conditions.

In this study, we have assessed the usability of a tactile belt prototype for clinical monitoring of physiologic patient data in the operating room under low workload (LW) and high workload (HW) conditions. In previous investigations, we have evaluated tactile technology in clinical settings and demonstrated that anesthesiologists have enhanced situational awareness towards adverse clinical events when a tactile display prototype is used as a supplemental monitoring device. To further evaluate the effectiveness of our tactile belt prototype, we compared the effects of workload on the performance of anesthesiologists in terms of accuracy and response time in tactile alert identification. We also administered a post-study questionnaire to evaluate the usability of the tactile belt as well as users' opinions about the device. We found that the response time to tactile alert identification to be faster under LW than under HW, however the accuracy of identification was not statistically different. Participants rated the tactile belt prototype as comfortable to use and the tactile alert scheme as easy to learn. Our findings further support the feasibility and efficacy of vibrotactile devices for enhancing physiological monitoring of patients in clinical environments.

Probabilistic assessment of Autonomic Nervous System fluctuations during tilt table tests.

A number of reports have advocated the use of Heart Rate Variability (HRV) as a non invasive method of monitoring the Autonomic Nervous System (ANS). In the anesthesia and critical care monitoring settings, the development of an instrument able to provide real-time information about the ANS state at different stages of any procedure would provide improved safety for patients undergoing diagnostic or therapeutic interventions. However, real-time analysis of HRV can be particularly challenging since larger effective lengths of observation provide better spectral resolution. Our study explores a probabilistic approach that analyzes changes in HRV parameters obtained from an autoregressive (AR) model technique using Burg's methods to evaluate very short observation windows while preserving appropriate frequency resolution. These HRV parameters are continuosly compared to a baseline state, and a probability trend is updated during provocative maneuvers. Preliminary results show that trends from classical parameters such as RMSSD and LFn are consistent and reliable instruments capable of providing significant information about ANS fluctuations in a timely fashion.

Current CHS and NHBPEP criteria for severe preeclampsia do not uniformly predict adverse maternal or perinatal outcomes.

OBJECTIVE: To determine the association between adverse maternal/perinatal outcomes and Canadian and U.S. preeclampsia severity criteria. METHODS: Using PIERS data (Preeclampsia Integrated Estimate of RiSk), an international continuous quality improvement project for women hospitalized with preeclampsia, we examined the association between preeclampsia severity criteria and adverse maternal and perinatal outcomes (univariable analysis, Fisher's exact test). Not evaluated were variables performed in <80% of pregnancies (e.g., 24-hour proteinuria). RESULTS: Few of the evaluated variables were associated with adverse maternal (chest pain/dyspnea, thrombocytopenia, 'elevated liver enzymes', HELLP syndrome, and creatinine >110 microM) or perinatal outcomes (dBP >110 mm Hg and suspected abruption) (at p < 0.01). CONCLUSIONS: In the PIERS cohort, most factors used in the Canadian or American classifications of severe preeclampsia do not predict adverse maternal and/or perinatal outcomes. Future classification systems should take this into account.