Dynamic asymmetry in cerebrospinal fluid pressure: An indicator of regional differences in compliance.

Background: Dural compliance influences the shape and magnitude of the cerebrospinal fluid (CSF) pulsations. In humans, cranial compliance is approximately 2× greater than spinal compliance; the differential has been attributed to the associated vasculature. In alligators, the spinal cord is surrounded by a large venous sinus, which suggests that the spinal compartment may have higher compliance than is found in mammals. Methods: Pressure catheters were surgically implanted into the cranial and spinal subdural spaces of eight subadult American alligators (Alligator mississippiensis). The CSF was propelled through the subdural space by orthostatic gradients and rapid changes in linear acceleration. Results: CSF pressure recordings taken from the cranial compartment were consistently, and significantly, larger than those taken from the spinal compartment. After the myodural bridge of Alligator was surgically released, the asymmetry in CSF pressure was decreased. Conclusion: Unlike the situation in humans, the spinal compartment of Alligator has greater compliance than the cranial compartment, presumably due to the presence of the large spinal venous sinus surrounding the dura. The change in CSF pressures after myodural surgical release supports the hypothesis that the myodural bridge functions, at least in part, to modulate dural compliance and the exchange of CSF between the cranial and spinal compartments.

Management of Enteroatmospheric Fistula (EAF) Using a Fistula-Vacuum Assisted Closure (VAC) in a Complicated Abdominal Trauma Case.

Enteroatmospheric fistula (EAF) is a relatively rare complication of patients undergoing open abdomen (OA) for damage control surgery. Mortality rates are high due to the increased risk of peritonitis, intraabdominal abscess, sepsis, and new perforations. There are a wide range of EAF management therapies in the literature, however, there are limited options on cases involving fistula-vaccum assisted closure (VAC) therapy. This case describes the treatment course of a 57-year-old, male admitted for blunt abdominal trauma secondary to a motor vehicle accident. Upon admission the patient underwent damage control surgery. The surgeons elected to have the patient's abdomen open, applying a mesh to promote healing. After several weeks of hospitalization an EAF was discovered in the abdominal wound subsequently managed by utilizing a fistula-VAC technique. Based on the successful outcome of this patient, fistula-VAC was shown as an effective way to promote wound healing while reducing the chances of complications.

Heart rate score and outcomes in ICD patients: insights from the prospective randomized INTRINSIC RV trial.

BACKGROUND: Heart rate score (HRSc), the percentage of atrial sensed and paced beats in the largest 10 beat/min bin of a device histogram and mean intrinsic heart rate (MIHR), predicted survival in nonrandomized studies of implantable defibrillator (ICD) patients. We evaluated whether HRSc and MIHR independently predicted mortality and heart failure (HF) hospitalization in the prospective, randomized, controlled INTRINSIC RV trial. METHODS AND RESULTS: The INTRINSIC RV trial enrolled 1530 patients receiving dual-chamber ICDs. This analysis involves patients (n = 1471) for whom MIHR and HRSc data were available. Mean follow-up was 10.4 months. The relationship between pre-randomization MIHR and HRSc on the primary endpoint of all-cause mortality and HF hospitalization was assessed using multivariate regression and Cox modeling. As categorical variables, MIHR > 70 bpm and HRSc > 70% were considered high. RESULTS: The median baseline MIHR and HRSc were 74 (IQR = 16) and 50% (IQR = 20) respectively. As a continuous variable, for every 1% increase in HRSc, death/HF hospitalization increased by 1% (95%CI: 1.002-1.017; p = 0.01). Regression analysis showed baseline MIHR was associated with HRSc (p = 0.01); for every 1 beat/min increase in MIHR, HRSc increased by 1.8%. A MIHR > 70 bpm and HRSc ≥ 70% predicted, but were independently associated with, the primary endpoint (HR: 1.39; 95%CI: 1.10-1.76, p = 0.005 for MIHR and HR: 1.654; 95%CI: 1.11-2.46, p = 0.01 for HRSc). Male gender (HR: 0.75), history of HF (HR: 1.29), and atrial fibrillation (HR: 1.37) also predicted death/hospitalization in the Cox model. CONCLUSIONS: In this large, prospectively studied ICD population, HRSc was a robust and independent predictor of death/HF hospitalization. High MIHR and high HRSc were associated but each predicted outcomes independently.

Open Reduction and Internal Fixation of a Pediatric Talar Body Fracture using a Medial Malleolar Osteotomy - A Case Report.

Introduction: Talus fracture injuries are rare and most literature pertains to fractures in skeletally mature adults. It is unusual for pediatric talus fractures to be treated operatively and is normally treated with immobilization. The location of the talus fracture required a medial malleolar osteotomy to facilitate exposure and reduction, which was fixed with temporary smooth K-wires. The authors were unable to identify a previous description of this technique in the literature. Case Report: An 11-year-old female was referred to our hospital due to polytraumatic injuries sustained in a roll-over MVC. A displaced fracture of the talus body was present. Due to the fracture location, a medial malleolar osteotomy was required for exposure. An open reduction and internal fixation was performed using subchondral minifragment screws under general anesthesia. The patient healed uneventfully, regained a normal gait and full, pain-free range of motion. Conclusions: Medial malleolar osteotomy with smooth K-wire fixation appears to be a safe method for gaining access to the talus when required for reduction and/or fixation of pediatric talus fractures.

Predicting the need for ICU admission in community-acquired pneumonia.

BACKGROUND: Multiple criteria have been proposed to define community-acquired pneumonia (CAP) severity and predict ICU admission. Validity studies have found differing results. We tested four models to assess severe CAP built upon the criteria included in the 2007 IDSA/ATS guidelines, hypothesizing that a model providing different weights for each individual criterion may be of better predictability. METHODS: Retrospective analysis of a prospective cohort study of adult hospitalizations for CAP at nine hospitals in Louisville, KY from June 2014 to May 2016. Four models were tested. Model 1: original 2007 IDSA/ATS criteria. Model 2: modified IDSA/ATS criteria by removing multilobar infiltrates and changing BUN threshold to ≥30 mg/dL; adding lactate level >2 mmol/L and requirement of non-invasive mechanical ventilation (NIMV). CAP was severe with 1 major criterion or 3 minor criteria. Model 3: same criteria as model 2, CAP was severe with 1 major criterion or 4 minor criteria. Model 4: multiple regression analysis including the modified criteria as described in models 2 and 3 with a score assigned to each variable according to the magnitude of association between variable and need for ICU. RESULTS: 8284 CAP hospitalizations were included. 1458 (18%) required ICU. Model 4 showed highest prediction of need for ICU with an area under the curve of 0.91, highest accuracy, specificity, positive predictive value, and agreement among models. CONCLUSION: Assigning differential weights to clinical predictive variables generated a score with accuracy that outperformed the original 2007 IDSA/ATS criteria for severe CAP and ICU admission.

The Role of the Cerebellum in Control of Swallow: Evidence of Inspiratory Activity During Swallow.

Anatomical connections are reported between the cerebellum and brainstem nuclei involved in swallow such as the nucleus tractus solitarius, nucleus ambiguus, and Kölliker-fuse nuclei. Despite these connections, a functional role of the cerebellum during swallow has not been elucidated. Therefore, we examined the effects of cerebellectomy on swallow muscle recruitment and swallow-breathing coordination in anesthetized freely breathing cats. Electromyograms were recorded from upper airway, pharyngeal, laryngeal, diaphragm, and chest wall muscles before and after complete cerebellectomy. Removal of the cerebellum reduced the excitability of swallow (i.e., swallow number), and muscle recruitment of the geniohyoid, thyroarytenoid, parasternal (chestwall), and diaphragm muscles, but did not disrupt swallow-breathing coordination. Additionally, diaphragm and parasternal muscle activity during swallow is reduced after cerebellectomy, while no changes were observed during breathing. These findings suggest the cerebellum modulates muscle excitability during recruitment, but not pattern or coordination of swallow with breathing.

Ultrasound probe use and reprocessing: Results from a national survey among U.S. infection preventionists.

BACKGROUND: Improper infection prevention practice associated with ultrasound probe use has been linked to increased infection risk, outbreaks, and death. Although guidelines for reprocessing and use of probes exist, it is unclear how extensively these have been adopted in practice. METHODS: Infection preventionists from U.S. health care facilities were surveyed (N = 358). The anonymous survey had 31 multiple choice, sliding scale, and text response questions. The survey was developed and deployed and the data were stored in the REDCap system. RESULTS: A high degree of noncompliance with U.S. guidelines was identified. Surface probes used in invasive procedures were not high-level disinfected or sterilized 15% (intraoperative) to 78% (peripheral line placements) of the time. Of invasive procedures, 5%-47% did not use sterile gel (same procedures, respectively). Of the participants, 20% were aware of instances where an ultrasound probe was used but was not correctly reprocessed. Extensive breaches of infection control guidelines were reported. The rapid expansion in use of ultrasound has brought clinical benefit but may be exposing patients to preventable infection risk. CONCLUSIONS: Infection preventionists are well placed to act as major drivers of change based on their expertise and experience in the management of infection risk across facilities and health systems. They, along with clinicians responsible for probe use and reprocessing, should review practices relating to ultrasound in their facilities. Where practice does not comply with guidelines, policy and training should be updated to ensure patient safety.

Pharmacological identification of cholinergic receptor subtypes on Drosophila melanogaster larval heart.

The Drosophila melanogaster heart is a popular model in which to study cardiac physiology and development. Progress has been made in understanding the role of endogenous compounds in regulating cardiac function in this model. It is well characterized that common neurotransmitters act on many peripheral and non-neuronal tissues as they flow through the hemolymph of insects. Many of these neuromodulators, including acetylcholine (ACh), have been shown to act directly on the D. melanogaster larval heart. ACh is a primary neurotransmitter in the central nervous system (CNS) of vertebrates and at the neuromuscular junctions on skeletal and cardiac tissue. In insects, ACh is the primary excitatory neurotransmitter of sensory neurons and is also prominent in the CNS. A full understanding regarding the regulation of the Drosophila cardiac physiology by the cholinergic system remains poorly understood. Here we use semi-intact D. melanogaster larvae to study the pharmacological profile of cholinergic receptor subtypes, nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors (mAChRs), in modulating heart rate (HR). Cholinergic receptor agonists, nicotine and muscarine both increase HR, while nAChR agonist clothianidin exhibits no significant effect when exposed to an open preparation at concentrations as low as 100 nM. In addition, both nAChR and mAChR antagonists increase HR as well but also display capabilities of blocking agonist actions. These results provide evidence that both of these receptor subtypes display functional significance in regulating the larval heart's pacemaker activity.