Computerized vital signs analysis and late onset infections in extremely low gestational age infants.

AIM: Current clinical and laboratory diagnostics for neonatal infection are inadequate. An infant's systemic inflammatory response may be identified earlier than clinical suspicion by a computerized algorithm (RALIS) incorporating multiple vital signs (VS). We tested the ability of RALIS to detect late onset infection (LOI) earlier than clinically suspected. METHODS: We conducted a retrospective review of infants enrolled in a birth cohort study at Prentice Women's Hospital. VS data (heart rate, respirations, temperature, desaturation, bradycardia) were extracted from electronic records of 73 premature infants (born ≤28 weeks' gestation; survived first month). RALIS generated a continuous output for the first 28 days of life. A score ≥5 for 6 h triggered an alert. The time of RALIS alert to time of clinical suspicion of infection (time culture sent) was measured for each episode of suspected and/or confirmed LOI. RESULTS: Among the 73 infants followed with RALIS, there were 34 episodes of culture-positive LOI, seven culture-negative but treated episodes, and 13 false-positive culture (untreated) episodes. Twenty-five infants had no culture-positive or treated sepsis events during the observation period. There was a positive linear association between alert and culture (ß=0.88, P<0.001). Mean absolute time difference between alert and culture was 59.4 h before culture. Sensitivity and specificity of RALIS for LOI were 0.82 and 0.44. CONCLUSION: The RALIS algorithm is a sensitive indicator for early detection of infection in preterm infants. Further modifications to improve the specificity of the algorithm are needed prior to application of VS modeling to patient antibiotic treatment decisions.

Pilot study of a new mathematical algorithm for early detection of late-onset sepsis in very low-birth-weight infants.

BACKGROUND: Diagnosis of late onset sepsis (LOS) in very low birth weight (VLBW) preterm infants relies mainly on clinical suspicion, whereas prognosis depends on early initiation of antibiotic treatment. RALIS is a mathematical algorithm for early detection of LOS incorporating six vital signs measured every 2 hours. OBJECTIVE: The aim of this study is to study RALIS ability to detect LOS before clinical suspicion. STUDY DESIGN: A total of 118 VLBW preterm infants (gestational age < 33 weeks, birth weight < 1,500 g) were enrolled in a prospective multicentered study. Vital signs were recorded prospectively up to day 21 of life in a blinded manner, with no effect on standard care. The primary end point was comparison of the rates and timing of detection of LOS between RALIS and clinical/culture evidence of LOS. RESULTS: Of the 2,174 monitoring days, RALIS indicated sepsis in 590 days, and LOS was positively diagnosed in 229 days. Sensitivity, specificity, positive, and negative predictive values were 74.6, 80.7, 38.8, and 95.1%, respectively. RALIS provided an indication for sepsis 3 days on the average before clinical suspicion. CONCLUSION: RALIS has a promising potential as an easy to implement noninvasive early indicator of LOS, especially for ruling out LOS in VLBW high-risk infants.

Vital signs analysis algorithm detects inflammatory response in premature infants with late onset sepsis and necrotizing enterocolitis.

BACKGROUND: Nonspecific clinical signs and suboptimal diagnostic tests limit accurate identification of late onset sepsis (LOS) and necrotizing enterocolitis (NEC) in premature infants, resulting in significant morbidity and antibiotic overuse. An infant's systemic inflammatory response may be identified earlier than clinical suspicion through analysis of multiple vital signs by a computerized algorithm (RALIS). AIM: To evaluate the revised RALIS algorithm for detection of LOS and NEC in preterm infants. METHODS: In this nested case-control study, VS data (heart rate, respiratory rate, temperature, desaturations, bradycardias) were extracted from medical records of infants 23-32 weeks gestation. RALIS generated an output, with score ≥ 5 triggering an alert. Patient episodes were classified based on culture, radiograph, and antibiotic data into categories: LOS, expanded LOS, NEC, and controls. Paired t-tests, linear regression and cross-validation analyses were used to evaluate the relationship between RALIS alert and LOS/NEC. RESULTS: Among 155 infants with 161 episodes, there were 41 expanded LOS (+blood, CSF, urine, respiratory culture), 31 LOS (+blood, CSF, urine), 9 NEC, and 93 controls. RALIS alert was 43.1 ±â€¯79 h before culture in LOS (p = .012). There was a significant association between RALIS alert and LOS/NEC (ß = 0.72, p < .0001). Sensitivity and specificity for LOS/NEC were 84% and 80%, (PPV = 63%; NPV = 93%). The regression model demonstrated an AUC of 89.9%. CONCLUSIONS: For infants ≤32 weeks, RALIS detects systemic inflammatory responses in LOS and NEC in the first month of life. The algorithm can identify infection earlier than clinical suspicion, even for NEC with negative cultures. RALIS has high NPV to rule-out LOS and NEC, and may, after prospective validation, aid in antibiotic treatment decisions.

Bedside laparotomy in the extremely low birth weight baby: a plea to bring the surgeon to the baby.

BACKGROUND: Babies born with extreme prematurity and low birth weight (< 1000 g) present a unique treatment challenge. In addition to the complexity of achieving survival, they may require surgical interventions for abdominal emergencies. Usually, these infants are transferred to a referral center for surgical treatment. Since 2000 our approach is bedside abdominal surgery at the referring center. OBJECTIVES: To evaluate whether the approach of bedside abdominal surgery at the referring center is safe and perhaps even beneficial for the baby. METHODS: We retrospectively reviewed our data since 2000 and included only babies weighing < 1000 g who were ventilated, suffered from hemodynamic instability, and underwent surgery for perforated bowel at the referring neonatal unit. Results were analyzed according to survival from the acute event (> 1 week), survival from the abdominal disease (> 30 days), and survival to discharge. RESULTS: Twelve babies met the inclusion criteria. Median weight at operation was 850 g (range 620-1000 g) and median age at birth was 25 weeks (range 23-27). Eleven infants survived the acute event (91.7%), 9 survived more than 30 days (81.8%), and 5 survived to discharge. CONCLUSIONS: Our results show that bedside laparotomy at the referring hospital is safe and feasible. A larger randomized study is indicated to prove the validity of this approach.

The Application of Biphasic Extrathoracic Cuirass-Assisted Ventilation in Normal Subjects Wearing Chemical-Biological-Radiological-Nuclear (CBRN) Gas Masks.

OBJECTIVE: Mobile RTX (MRTX), a portable light-weighted ventilator, provides noninvasive respiratory support using biphasic extrathoracic cuirass-assisted ventilation. Despite the effectiveness of chemical-biological-radiological-nuclear (CBRN) gas masks, they cause respiratory loading as a result of added dead space and resistance. This prospective comparative pilot study was conducted to investigate the safety and efficacy of assisted ventilation provided by MRTX in healthy adult volunteers wearing CBRN gas masks at rest. METHODS: Cardiorespiratory parameters were monitored in 11 healthy adult volunteers breathing spontaneously or with assisted ventilation provided by MRTX, freely or with the mask on. Comparisons were made by single-factor analysis of variance. RESULTS: AV significantly increased minute ventilation (p < 0.001). MRTX increased minute ventilation by 6.4 L/min (mean, 95% confidence interval: 3.1, 9.8; p < 0.005) and by 4.7 L/min (1.8, 7.5; p < 0.01) during spontaneous breathing and with the mask on, respectively. Simultaneously, end-tidal carbon dioxide partial pressure decreased by 3.6 mmHg (2.2, 5.1; p < 0.001) and by 6.5 mmHg (3.8, 9.1; p < 0.001). DISCUSSION: Biphasic extrathoracic cuirass assisted ventilation provided by MRTX is safe and effective in supporting adequate needs at rest even when wearing protective masks. MRTX should be further assessed as a possible adjunct to currently used field ventilation in CBRN scenarios.

Controlled assembly of hybrid bulk-heterojunction solar cells by sequential deposition.

This work presents a technique to create ordered and easily characterized hybrid nanocrystal-polymer composites by sequential deposition of tetrapod-shaped cadmium telluride (CdTe) nanocrystals and poly(3-hexlythiophene). With controlled fabrication and composite morphology, these devices offer several advantages over traditional co-deposited hybrid cells and provide a model system for detailed investigation into the operation of bulk-heterojunction cells.

Biphasic cuirass ventilation is better than bag-valve mask ventilation for resuscitation following organophosphate poisoning.

OBJECTIVE: Exposure to organophosphates (OP) may lead to a life threatening cholinergic crisis with death attributed to a rapidly progressive respiratory failure. In a toxicological mass casualty event involving organophosphate exposure, many of the victims may depend on immediate short-term ventilation to overcome the respiratory distress which may exhaust life supporting resources. In addition, the mandatory use of personal protective gear by first responders emphasizes the need for a noninvasive, easy-to-operate ventilation device. Our objective was to assess the efficacy of MRTX, a Biphasic Cuirass Ventilation device, in comparison with standard bag-valve mask ventilation following acute organophosphate poisoning. METHODS: Pigs were exposed to paraoxon poisoning (1.4 LD50), and treated 8 min later with atropine (0.05 mg/kg). The control group received no further support (n = 9), the two experimental groups received ventilation support initiated 15 min post exposure and lasted for 25 min: one group was ventilated with the commonly used bag-valve mask (Mask group, n = 7) and the other was ventilated with the Biphasic Cuirass Ventilation device (Cuirass group, n = 7). Clinical signs and physiological parameters were monitored during the first hour, and mortality up to 24 h post exposure was recorded. RESULTS: No mortality was observed in the Cuirass group following OP poisoning, while mortality in the Control and in the Mask groups was high (67% and 71%, respectively). Mouth excretions of the cuirass-ventilated animals were frothy white as in deep suctioning, as opposed to the clear saliva-like appearance of secretions in the other two groups. No further group differences were recorded. CONCLUSIONS: The noninvasive, easy-to-operate Biphasic Cuirass Ventilation device was effective in reducing OP-induced mortality and might be advantageous in an organophosphate mass casualty event. This finding should be validated in further investigations.

Comparison of the usefulness of heart rate variability versus exercise stress testing for the detection of myocardial ischemia in patients without known coronary artery disease.

Heart rate variability (HRV) has been shown to be attenuated in patients with coronary artery disease (CAD) and may, therefore, be possibly used for the early detection of myocardial ischemia. We aimed to evaluate the diagnostic yield of a novel short-term HRV algorithm for the detection of myocardial ischemia in subjects without known CAD. We prospectively enrolled 450 subjects without known CAD who were referred to tertiary medical centers for exercise stress testing (EST) with single-photon emission computed tomography myocardial perfusion imaging (MPI). All subjects underwent 1-hour Holter testing with subsequent HRV analysis before EST with MPI. The diagnostic yield of HRV analysis was compared with EST, using MPI as the gold standard for the noninvasive detection of myocardial ischemia. All subjects had intermediate pretest probability for CAD. Mean age was 62 years, 38% were women, 51% had hypertension, and 25% diabetes mellitus. HRV analysis showed superior sensitivity (77%) compared with standard EST (27%). After multivariate adjustment, HRV was independently associated with an 8.4-fold (p <0.001) increased likelihood for the detection of myocardial ischemia by MPI, whereas EST did not show a statistically significant association with a positive MPI (odds ratio 2.1; p = 0.12). Of subjects who were referred for subsequent coronary angiography, the respective sensitivities of HRV and EST for the detection of significant CAD were 73% versus 26%. Our data suggest that HRV can be used as an important noninvasive technique for the detection of myocardial ischemia in subjects without known CAD, providing superior sensitivity to conventional EST in this population.

Intraosseous emergency access by physicians wearing full protective gear.

OBJECTIVES: To assess prospectively and randomly the feasibility, speed, and success rate of establishing an intraosseous access using the Bone Injection Gun (BIG) while wearing antichemical outfits. METHODS: Attempts to introduce intraosseous injection with or without a full protective gear (antichemical body suit, face mask, and butyl gloves) were performed using a turkey bone model. Time to proper placement was measured. RESULTS: The average time to successfully insert the BIG's needle while wearing a protective gear was 32 +/- 3 seconds compared with 22 +/- 2 seconds (p<0.05) without the outfit. Success rate was greater than or equal to 80%. When failure occurred, a second attempt always proved successful. CONCLUSIONS: The intraosseous insertion of the BIG's needle is rapid and easy but requires 50% more time when wearing protective gear than without it. Its use during emergent treatment of toxic mass casualty is of potential benefit and needs further investigation.

Application of a cuirass and institution of biphasic extra-thoracic ventilation by gear-protected physicians.

OBJECTIVES: To evaluate the speed by which cuirass application, followed by biphasic extra-thoracic ventilation, can be instituted by full anti-chemical protective gear-wearing physicians. MATERIALS AND METHODS: Ten physicians of variable subspecialties applied a cuirass on an adult volunteer and instituted biphasic extra-thoracic ventilation, using the RTX respirator (Medivent, London, UK). Endotracheal (ET) intubation and manual ventilation of a mannequin and its ventilation was comparatively assessed. Performances were conducted in a prospective, crossover, randomized manner. Times to successful applications as well as failure rates were recorded. RESULTS: Cuirass application was performed more rapidly (102 +/- 9 s, 177 +/- 31 s, respectively, P <.01) and with a slightly lower failure rate than ET intubation. CONCLUSIONS: Physicians wearing full anti-chemical protective gear applied the cuirass and instituted biphasic extra-thoracic ventilation faster than ET intubation and manual positive pressure ventilation. Extra-thoracic ventilation should be further evaluated as an option for emergent respiratory support during toxic mass casualty events.

A mathematical algorithm for detection of late-onset sepsis in very-low birth weight infants: a preliminary diagnostic test evaluation.

OBJECTIVE: To study the diagnostic ability of RALIS (computerized mathematical algorithm and continuous monitoring device) to detect late onset sepsis among very low birth weight preterm neonates. METHODS: Randomly chosen 24 very low birth weight infants with proven sepsis were compared to 22 infants without sepsis. The clinical parameters were retrospectively collected from the medical records. The ability of RALIS to detect late onset sepsis was calculated. RESULTS: RALIS positively identified 23 of the 24 infants with sepsis (sensitivity 95.8%). It indicated sepsis alert median 2.0 days earlier than clinical suspicion. A false positive alert was indicated in 23% (5/22) infants. The specificity, and positive and negative predictive ability of RALIS were 77.3%. 82.1% and 94.4%, respectively. CONCLUSION: RALIS may aid in the early diagnosis of late onset sepsis in very low birth weight preterm infants.

Hybrid solar cells with prescribed nanoscale morphologies based on hyperbranched semiconductor nanocrystals.

In recent years, the search to develop large-area solar cells at low cost has led to research on photovoltaic (PV) systems based on nanocomposites containing conjugated polymers. These composite films can be synthesized and processed at lower costs and with greater versatility than the solid state inorganic semiconductors that comprise today's solar cells. However, the best nanocomposite solar cells are based on a complex architecture, consisting of a fine blend of interpenetrating and percolating donor and acceptor materials. Cell performance is strongly dependent on blend morphology, and solution-based fabrication techniques often result in uncontrolled and irreproducible blends, whose composite morphologies are difficult to characterize accurately. Here we incorporate three-dimensional hyperbranched colloidal semiconductor nanocrystals in solution-processed hybrid organic-inorganic solar cells, yielding reproducible and controlled nanoscale morphology.

Duodenojejunal atresia with absent dorsal mesentery, choledochal cyst, and malrotation in a premature newborn--a case report.

We present the case of a premature baby who was born with the following conditions: an extensive atresia from the first part of the duodenum to the mid small bowel; malrotation of the distal part, in volvulus and in an "apple peel" configuration; no connection of the bile ducts to the bowel; and presence of a type II choledochal cyst. To our knowledge, this is the first case in which a combination of these anomalies is reported. A brief review of the relevant literature is also presented.

Biphasic extrathoracic cuirass ventilation for resuscitation.

PURPOSES: The MRTX portable lightweight respirator (MRTX) provides noninvasive respiratory support using biphasic extrathoracic ventilation via a cuirass fitted around the patient's chest. METHODS: MRTX was applied with or without full protective gear, on adult volunteers simulating nerve agent (NA) victims by nonmedical caregivers. Assessment was made based on scores for correct positioning of the cuirass, quality of seal, and rapidness. RESULTS: For the unprotected and protected personnel, the respective median (+/-95% confidence interval) scores for correct positioning of the cuirass were 2 (1.4-1.9) and 1 (1.2-1.8) (n = 15 per group, P = NS); quality of seal scores were 2 (1.5-2.0) and 2 (1.3-1.8) ( P = NS); and mean (+/-SD) time required for instituting mechanical ventilation was 90.5 +/- 10.9 and 100.3 +/- 7.9 seconds ( P < .05). The respirator was activated at first attempt 11 times in the group of 15 without protective gear and 8 times in the group of 15 with protective gear ( P = NS). DISCUSSION: Biphasic cuirass ventilation is an easily learned and rapidly applied method suitable for use by nonmedical personnel, even when wearing cumbersome protective gear.

Air-stable all-inorganic nanocrystal solar cells processed from solution.

We introduce an ultrathin donor-acceptor solar cell composed entirely of inorganic nanocrystals spin-cast from solution. These devices are stable in air, and post-fabrication processing allows for power conversion efficiencies approaching 3% in initial tests. This demonstration elucidates a class of photovoltaic devices with potential for stable, low-cost power generation.