Rapid and Efficient Computation of Cell Paths During Ultrasonic Focusing.

This biophysical analysis explores the first-principles physics of movement of white blood cell sized particles, suspended in an aqueous fluid and experiencing progressive or standing waves of acoustic pressure. In many current applications the cells are gradually nudged or herded toward the nodes of the standing wave, providing a degree of acoustic focusing and concentration of the cells in layers perpendicular to the direction of sound propagation. Here the underlying biomechanics of this phenomenon are analyzed specifically for the viscous regime of water and for small diameter microscopic spheroids such as living cells. The resulting mathematical model leads to a single algebraic expression for the creep or drift velocity as a function of sound frequency, amplitude, wavelength, fluid viscosity, boundary dimensions, and boundary reflectivity. This expression can be integrated numerically by a simple and fast computer algorithm to demonstrate net movement of particles as a function of time, providing a guide to optimization in a variety of emerging applications of ultrasonic cell focusing.

Use of weak DC electric fields to rapidly align mammalian cells.

Objective.The ability to modulate cell morphology has clinical relevance in regenerative biology. For example, cells of the skeletal muscle, peripheral nerve and vasculature have specific oriented architectures that emerge from unique structure-function relationships. Methods that can induce similar cell morphologiesin vitrocan be of use in the development of biomimetic constructs for the repair or replacement of damaged tissues. In this work, we demonstrate that direct current (DC) electric fields (EFs) can be used as a tool to globally align cell populationsin vitro. Approach.Using a 2D culture chamber system, we were able to quickly (within hours) align Schwann cells at different culture densities with an application of steady EFs at 200-500 mV mm-1.Main results.Cellular alignment was perpendicular to the field vector and varied proportionately as a function of field magnitude. In addition, the degree of cellular alignment was also dependent on cellular density. Even well-established Schwann cell monolayers were responsive to the applied DC fields with cells retracting parallel oriented processes (with respect to the imposed field) and re-extending them along the perpendicular axis. When the DC field was removed, monolayers retained the aligned morphology for many days afterwards, likely due to contact inhibition. We further show the method is applicable to other field-responsive cells, such as 3T3 fibroblasts.Significance.The patterned cells provided nanoscale haptotactic cues and can be subsequently used as a basal layer for co-culturing or manipulated for other applications. DC fields represent a rapid, simple, and efficient technique compared to other cell patterning methods such as substrate manipulation.

Impact of paediatric tonsillectomy perioperative management on pain, nausea and recovery: A prospective cohort study.

AIM: Tonsillectomy procedures are a core element of paediatrics; however, perioperative management differs. This study aimed to describe tonsillectomy management, including the burden of pain, nausea and delayed recovery. METHODS: A prospective cohort study was undertaken through an audit of tonsillectomy perioperative practice and recovery and survey interviews with family members 7-14 days post-surgery. The study was undertaken at an Australian tertiary referral paediatric hospital between June and September 2016. RESULTS: The audit included 255 children undergoing tonsillectomy, with 127 family members interviewed. Most participants underwent adenotonsillectomy (n = 216; 85%), with a primary diagnosis of obstructive sleep apnoea (n = 205; 80%) and a mean age of 7 years (standard deviation; 3.9). A variety of intra-operative pain relief and antiemetics was administered. Pain was present in 29% (n = 26) of participants at ward return, increasing to 32-45% at 4-20 h and decreasing to 21% (n = 15) at discharge. A third of the children (32%; n = 41) had moderate to severe pain at post-discharge interview, and 30% (n = 38) experienced nausea at home. Most parents (82%; n = 104) were still giving regular paracetamol at 7 days post-operatively, and 31% (n = 39) had finished their oxycodone. Of the participants, 14% (n = 26) presented to the emergency department within 7 days of discharge; 8% (n = 20) of the total cohort were re-admitted. CONCLUSIONS: There was variety in perioperative and post-discharge care. Pain scores were infrequently documented post-tonsillectomy, and parents are generally dissatisfied with the management of post-operative pain and nausea. Further research is needed to provide a more consistent approach to perioperative management to promote recovery.

Implementation of a new dantrolene formulation across a multifacility health system.

PURPOSE: An initiative to optimize the treatment of malignant hyperthermia in surgical patients through a dantrolene product conversion program is described. SUMMARY: A large health system's formulary evaluation of a new dantrolene sodium product indicated that despite a higher cost per treatment course, the product could offer key advantages over older formulations of dantrolene in terms of preparation and administration time, product content, and storage requirements. A work group, consisting of pharmacy personnel, an anesthesiologist, a nurse anesthetist, and a representative of the health system's group purchasing organization, determined that a switch to the new dantrolene product would offer both patient care benefits and process benefits. With the approval of the health system's pharmacy and therapeutics committee, the new product was added to the formulary as the preferred dosage form of dantrolene, and existing dantrolene product stock was converted to the new formulation. Key implementation steps included (1) concurrent replacement of dantrolene stock on all "malignant hyperthermia carts" across the 15-hospital health system, (2) development of educational materials to raise awareness of the conversion and revised product preparation procedures, (3) anesthesiology provider and pharmacy staff education, (4) revision of dantrolene listings in each hospital's computerized prescriber-order-entry system, and (5) redistribution of returned dantrolene product stock. The dantrolene product conversion occurred over a four-month period. CONCLUSION: A multifacility health system was successful in converting an existing stock of dantrolene to a newly available formulation.

Nursing admissions process redesigned to leverage EHR.

Among the challenges facing nurses in acute care facilities are duplicate documentation, complex rules for coordinating care, and pressure to accelerate patient discharge. Christiana Care, a two-hospital, 900-bed health system in Delaware, redesigned its nursing admissions process to address these issues and provide a centralized source of assessment information. An interdisciplinary team redesigned the assessment process to leverage the clinical documentation, decision support, and workflow tools of Christiana Care's evolving electronic health record. Nurses use a wireless device at the patient's bedside to enter admission information. A series of decision-support rules evaluate the information and send electronic referrals to appropriate ancillary departments. Departments electronically document interventions that can be tracked by nursing, closing the loop.A dedicated rollout coordinator and system-generated audit reports were critical to early identification and resolution of several implementation problems. The new process has not only simplified the work of nursing but led to more appropriate referrals to the ancillary departments. More than 25 percent of the patients have information imported from a previous encounter, eliminating duplicate documentation and improving patient satisfaction. Admission information also is being used to monitor and support a variety of quality efforts, including core measures.