Effect of vertical stopcock position on start-up fluid delivery in syringe pumps used for microinfusions

The purpose of this in vitro study was to evaluate the impact of the vertical level of the stopcock connecting the infusion line to the central venous catheter on start-up fluid delivery in microinfusions. Start-up fluid delivery was measured under standardized conditions with the syringe outlet and liquid flow sensors positioned at heart level (0 cm) and exposed to a simulated CVP of 10 mmHg at a set flow rate of 1 ml/h. Flow and intraluminal pressures were measured with the infusion line connected to the stopcock primarily placed at vertical levels of 0 cm, + 30 cm and - 30 cm or primarily placed at 0 cm and secondarily, after connecting the infusion line, displaced to + 30 cm and - 30 cm. Start-up fluid delivery 10 s after opening the stopcock placed at zero level and after opening the stopcock primarily connected at zero level and secondary displaced to vertical levels of + 30 cm and - 30 cm were similar (- 10.52 [- 13.85 to - 7.19] µL; - 8.84 [- 12.34 to - 5.33] µL and - 11.19 [- 13.71 to - 8.67] µL (p = 0.469)). Fluid delivered at 360 s related to 65% (zero level), 71% (+ 30 cm) and 67% (- 30 cm) of calculated infusion volume (p = 0.395). Start-up fluid delivery with the stopcock primarily placed at + 30 cm and - 30 cm resulted in large anterograde and retrograde fluid volumes of 34.39 [33.43 to 35.34] µL and - 24.90 [- 27.79 to - 22.01] µL at 10 s, respectively (p < 0.0001). Fluid delivered with the stopcock primarily placed at + 30 cm and - 30 cm resulted in 140% and 35% of calculated volume at 360 s, respectively (p < 0.0001). Syringe infusion pumps should ideally be connected to the stopcock positioned at heart level in order to minimize the amounts of anterograde and retrograde fluid volumes after opening of the stopcock.

Pressure-adjusted venting eliminates start-up delays and compensates for vertical position of syringe infusion pumps used for microinfusion

Microinfusions are commonly used for the administration of catecholamines, but start-up delays pose a problem for reliable and timely drug delivery. Recent findings show that venting of the syringe infusion pump with draining of fluid to ambient pressure before directing the flow towards the central venous catheter does not counteract start-up delays. With the aim to reduce start-up delays, this study compared fluid delivery during start-up of syringe infusion pumps without venting, with ambient pressure venting, and with central venous pressure (CVP)-adjusted venting. Start-up fluid delivery from syringe pumps using a microinfusion of 1 mL/h was assessed by means of liquid flow measurement at 10, 60, 180 and 360 s after opening the stopcock and starting the pump. Assessments were performed using no venting, ambient pressure venting or CVP-adjusted venting, with the pump placed either at zero, - 43 cm or + 43 cm level and exposed to a simulated CVP of 10 mmHg. Measured fluid delivery was closest to the calculated fluid delivery for CVP-adjusted venting (87% to 100% at the different timepoints). The largest deviations were found for ambient pressure venting (- 1151% to + 82%). At 360 s after start-up 72% to 92% of expected fluid volumes were delivered without venting, 46% to 82% with ambient pressure venting and 96% to 99% with CVP-adjusted venting. CVP-adjusted venting demonstrated consistent results across vertical pump placements (p = 0.485), whereas the other methods had significant variances (p < 0.001 for both). In conclusion, CVP-adjusted venting effectively eliminates imprecise drug delivery and start-up delays when using microinfusions.

Robotic Versus Open Hepatic Arterial Infusion Pump Placement for Unresectable Intrahepatic Cholangiocarcinoma

BACKGROUND

Hepatic arterial infusion pump (HAIP) chemotherapy is an effective treatment for patients with unresectable intrahepatic cholangiocarcinoma (iCCA). HAIP chemotherapy requires a catheter inserted in the gastroduodenal artery and a subcutaneous pump. The catheter can be placed using an open or robotic approach.

OBJECTIVE

This study aimed to compare perioperative outcomes of robotic versus open HAIP placement in patients with unresectable iCCA.

METHODS

We analyzed patients with unresectable iCCA included in the PUMP-II trial from January 2020 to September 2022 undergoing robotic or open HAIP placement at Amsterdam UMC, Erasmus MC, and UMC Utrecht. The primary outcome was time to functional recovery (TTFR).

RESULTS

In total, 22 robotic and 28 open HAIP placements were performed. The median TTFR was 2 days after robotic placement versus 5 days after open HAIP placement (p < 0.001). One patient (4.5%) in the robotic group underwent a conversion to open because of a large bulky tumor leaning on the hilum immobilizing the liver. Postoperative complications were similar-36% (8/22) after robotic placement versus 39% (11/28) after open placement (p = 1.000). The median length of hospital stay was shorter in the robotic group-3 versus 5 days (p < 0.001). All 22 robotic patients initiated HAIP chemotherapy post-surgery, i.e. 93% (26/28) in the open group (p = 0.497). The median time to start HAIP chemotherapy was 14 versus 18 days (p = 0.153).

CONCLUSION

Robotic HAIP placement in patients with unresectable iCCA is a safe and effective procedure and is associated with a significantly shorter TTFR and hospital stay than open HAIP placement.

Design of uncertain displacement controlled velocity control system for hydraulic actuator

Displacement-controlled systems have high efficiency and are widely used in industry. Accurate control of the actuator motion in hydraulic systems is usually a necessity in industrial applications such as the motion of control surfaces in fixed-wing airplanes for flight control as well as the aircraft brake systems. To address this need, the current study was conducted with the goal of developing a high-fidelity model to achieve precise control. This work focused on modeling a hydrostatic transmission that is used for controlling a linear actuator velocity. The flow entering the actuator was changed using a variable displacement pump. The study included examining the stability and performance of the open-loop system. Additionally, the study involved the design of the proportional-integral-derivative PID and H∞ controllers, followed by the analysis of the stability and performance of the closed-loop system with both controllers. Furthermore, the multiplicative uncertainty is taken into account and the robustness of the system is verified using controllers PID and H∞. In the current study,Uncertain parameters such as actuator efficiency, pump speed, and viscous friction coefficient were considered and allowed for a ±5% deviation from their stated values. Taking uncertainty into account ensures that the system performs properly even in case where the design parameters vary within the specified range. The system response is compared for the cases of open-loop system, closed-loop system with PID controller, and closed-loop system with H∞ controller. The results demonstrated that the open-loop system remains stable for real-world applications but shows insufficient performance in terms of input tracking and disturbance rejection. The introduction of the PID controller significantly enhanced the system's response to a reference input; however, its disturbance rejection capabilities in terms of overshoot and settling time were still unsatisfactory. The system equipped with the PID controller failed to meet the robustness requirements. Conversely, the utilization of H ∞ controllers yielded superior responses and fulfilled the robustness criteria.

Subcutaneous immunoglobulin replacement therapy in patients with immunodeficiencies - impact of drug packaging and administration method on patient reported outcomes

BACKGROUND

Here, the perspective of patients with primary and secondary immunodeficiency receiving subcutaneous immunoglobulin (SCIg) via introductory smaller size pre-filled syringes (PFS) or vials were compared.

METHODS

An online survey was conducted in Canada by the Association des Patients Immunodéficients du Québec (APIQ) (10/2020-03/2021). Survey questions included: reasons for choosing SCIg packaging and administration methods, training experiences, infusion characteristics, and switching methods. The survey captured structured patient-reported outcomes: treatment satisfaction and its sub-domains, symptom state, general health perception, and physical and mental function. Respondents using PFS were compared with vial users, overall and stratified by their administration method (pump or manual push).

RESULTS

Of the 132 total respondents, 66 respondents used vials, with 38 using a pump and 28 using manual push. PFS (5 and 10 mL sizes) were being used by 120 respondents, with 38 using a pump and 82 using manual push. PFS users were associated with a 17% lower median (interquartile range) SCIg dose (10 [8, 12] vs. 12 [9, 16] g/week, respectively), a significantly shorter infusion preparation time (15 [10, 20] vs. 15 [10, 30] mins, respectively), and a trend for shorter length of infusion (60 [35, 90] vs. 70 [48, 90] mins, respectively) compared with those on vials. Patient-reported treatment satisfaction scores were overall similar between vial and PFS users (including on the domains of effectiveness and convenience), except for a higher score for vials over PFS on the domain of global satisfaction (p=0.02).

CONCLUSIONS

Consistent with prescribing that reflects a recognition of less wastage, PFS users were associated with a significantly lower SCIg dose compared with vial users. PFS users were also associated with shorter pre-infusion times, reflecting simpler administration mechanics compared with vial users. Higher global satisfaction with treatment among vial users compared with PFS users was consistent with users being limited to smaller PFS size options in Canada during the study period. Patient experience on PFS is expected to improve with the introduction of larger PFS sizes. Overall, treatment satisfaction for SCIg remains consistently high with the introduction of PFS packaging compared with vials.

Evaluation of the venting principle to reduce start-up delays in syringe infusion pumps used for microinfusions

Start-up delays of syringe pump assemblies can impede the timely commencement of an effective drug therapy when using microinfusions in hemodynamically unstable patients. The application of the venting principle has been proposed to eliminate start-up delays in syringe pump assemblies. However, effectively delivered infusion volumes using this strategy have so far not been measured. This invitro study used two experimental setups to measure the effect of the venting principle compared to a standard non-venting approach on delivered start-up infusion volumes at various timepoints, backflow volumes, flow inversion and zero drug delivery times by means of liquid flow measurements at flow rates of 0.5, 1.0 and 2.0 mL/h. Measured delivered initial start-up volumes were negative with all flow rates in the vented and non-vented setup. Maximum backflow volumes were 1.8 [95% CI 1.6 to 2.3] times larger in the vented setup compared to the non-vented setup (p < 0.0001). Conversely, times until flow inversion were 1.5 [95% CI 1.1 to 2.9] times shorter in the vented setup (p < 0.002). This led to comparable zero drug delivery times between the two setups (p = 0.294). Start-up times as defined by the achievement of at least 90% of steady state flow rate were achieved faster with the vented setup (p < 0.0001), but this was counteracted by the increased backflow volumes. The application of the venting principle to the start-up of microinfusions does not improve the timely delivery of drugs to the patient since the faster start-up times are counteracted by higher backflow volumes when opening the three-way stopcock.

Double-Barrel Perfusion System for Modification of Luminal Contents of Intestinal Organoids

Organoids are 3D cultures of self-organized adult or pluripotent stem cells with an epithelial membrane enclosing a defined fluid-filled lumen. These organoids have been demonstrated with a wide range of organotypic tissue types, but the enclosed nature of the structure restricts access to the lumen and apical surface of the cell membrane. To increase the potential applications of organoids, new technologies are required to provide access to the lumen of the organoid and apical surface of the epithelial cell membrane to enable new biomedical studies. This chapter details a method to access the lumen and apical surface of an organoid utilizing a double-barrel pulled glass capillary and pressure-based pump. The organoid perfusion system uses a three-axis micromanipulator to position the double-barrel capillary to pierce the organoid with the tip of the capillary. Each barrel of the double-barrel capillary is controlled independently with the pressure-based pump to allow injection and removal of material into and from the lumen. Additionally, the organoid is immobilized with a custom-designed PDMS organoid holder. The design of the components for the organoid perfusion system and details on their use are presented here and can be utilized as the basis to enable a wide range of organoid studies including but not limited to modifying luminal contents and apical cell membrane interactions during organoid cultures, recapitulation of physiological flow within the normally static organoid lumen, and effects of mechanical strain on organoid cell development.

Current Practices in Hepatic Artery Infusion (HAI) Chemotherapy: An International Survey of the HAI Consortium Research Network

BACKGROUND

An increasing number of hepatic artery infusion (HAI) programs have been established worldwide. Practice patterns for this complex therapy across these programs have not been reported. This survey aimed to identify current practice patterns in HAI therapy with the long-term goal of defining best practices and performing prospective studies.

METHODS

Using SurveyMonkeyTM, a 28-question survey assessing current practices in HAI was developed by 12 HAI Consortium Research Network (HCRN) surgical oncologists. Content analysis was used to code textual responses, and the frequency of categories was calculated. Scores for rank-order questions were generated by calculating average ranking for each answer choice.

RESULTS

Thirty-six (72%) HCRN members responded to the survey. The most common intended initial indications for HAI at new programs were unresectable colorectal liver metastases (uCRLM; 100%) and unresectable intrahepatic cholangiocarcinoma (uIHC; 56%). Practice patterns evolved such that uCRLM (94%) and adjuvant therapy for CRLM (adjCRLM; 72%) have become the most common current indications for HAI at established centers. Referral patterns for pump placement differed between uCRLM and uIHC, with most patients referred while receiving second- and first-line therapy, respectively, with physicians preferring to evaluate patients for HAI while receiving first-line therapy for CRLM. Concern for extrahepatic disease was ranked as the most important factor when considering a patient for HAI.

CONCLUSIONS

Indication and patient selection factors for HAI therapy are relatively uniform across most HCRN centers. The increasing use of adjuvant HAI therapy and overall consistency of practice patterns among HCRN centers provides a robust environment for prospective data collection and randomized clinical trials.

Prevalence and Description of the Skin Reactions Associated with Adhesives in Diabetes Technology Devices in an Adult Population: Results of the CUTADIAB Study

Objective: The use of continuous glucose monitoring (CGM) systems and continuous subcutaneous insulin infusion (CSII) devices adhering to the skin can lead to skin reactions. The objective was to determine the prevalence and consequences of skin reactions at CGM or CSII sites in a large unbiased population. Research Design and Methods: This is a cross-sectional multicenter study. All adult patients with diabetes seen in consultation over a period of 7 months and using or having used a system with skin adhesives (in the last 10 years) were included and filled out a self-assessment questionnaire. Results: Among 851 patients, skin reaction was reported in 28% with CGM and 29% with CSII. Patients reporting reactions were more frequently women using CGM and CSII, and CGM users had type 1 more often than type 2 diabetes (P < 0.001). Manifestations were similar for reactions to CGM and CSII: redness and pruritus in 70%-75% of patients with reactions, pain in 20%-25%, and vesicles and desquamation in 12%-15%. Manifestations occurred within the first 24 h of first use in 22%-24% of patients with reactions to CGM and CSII, but after more than 6 months in 38% and 47% of patients with reactions to CGM and CSII, respectively. Device use was definitively stopped in 12% of patients with reactions to CGM (3.2% of all users) and 7% with reactions to CSII (2.1% of all users). Conclusions: Skin reactions were common, with similar presentations in CGM and CSII users. Manifestations suggested skin irritation rather than allergies. These reactions rarely led to the definitive discontinuation of the use of the device.

Intrathecal Baclofen and Opioid Therapy: Cerebrospinal Fluid Leak and Infection Incidence, Risk Factors, and Outcomes

BACKGROUND

Intrathecal drug therapy treats medically refractory spasticity and pain. cerebrospinal fluid (CSF) leak or infection can limit efficacy and increase morbidity. We aim to evaluate risk factors and outcomes after CSF leaks and infections requiring reoperation.

MATERIALS AND METHODS

We retrospectively analyzed our 7-year experience of intrathecal baclofen and opioid operations using a protocol designed to limit CSF leakage and infections. Postoperative complication incidence and risk factors for reoperation were compared with published reports. We assessed outcomes after these complications.

RESULTS

We analyzed 282 intrathecal baclofen (ITB) and intrathecal opioid (ITO) therapy operations (mean 2.27-year follow-up). 21% developed CSF leaks overall with similar incidences in ITB and ITO patients (19% vs. 25%, p0.3). Overall, 5% of patients developed deep infections with similar incidences between ITB and ITO cohorts (6% vs. 4%, p0.6). Tobacco use and age <50 years were significantly associated with CSF leak in ITO operations. Underweight body mass index, immunosuppression, tobacco use, and primary implantation were associated with infection. When CSF leak or infection occurred, patients suffered more perioperative adverse events and had elevated 90-day readmission rate compared with those without these complications.

CONCLUSIONS

Our 7-year ITB and ITO therapy using the 8781 Ascenda intrathecal catheter highlights a higher reoperation rate for CSF leak and similar infection incidence to reports using traditional catheters. Multiple modifiable risk factors for CSF leak include recent tobacco use among ITO patients. Body mass index optimization and immunosuppressant elimination may reduce reoperation for infection.

Relationship of OqxAB efflux pump to antibiotic resistance, mainly fluoroquinolones in Klebsiella pneumoniae, isolated from hospitalized patients

Objectives

This research was designed to study the prevalence of OqxAB efflux pump genes and also to investigate the relationship between efflux pump and resistance to antibiotics, especially to fluoroquinolones, evaluate the expression levels of OqxAB genes, and molecular typing of Klebsiella pneumoniae isolated from hospitalized patients in Hamadan hospitals, west of Iran.

Materials and Methods

In a cross-sectional study, 100 clinical strains of K. pneumoniae were isolated from hospitalized patients in three major teaching hospitals from January to June 2021. The antibiotic susceptibility of isolates was evaluated by the disk-diffusion agar method. The frequency of genes encoding oqxA and oqxB of efflux pump genes was investigated by PCR, and the expression of the oqxA efflux pump gene was investigated by the Real-time PCR method. The genetic relationship of K. pneumoniae isolates was analyzed by the Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR technique.

Results

According to our results, the multi-drug resistance phenotype (MDR) in 65% and high prevalence resistance to ciprofloxacin in 89% of K. pneumoniae isolates was detected. The higher prevalence of oqxA (95%) and oqxB (98%) was also detected. There was a significant relationship between ciprofloxacin resistance and the oqxB gene as well as between ceftriaxone and chloramphenicol resistance and the oqxA gene. The expression of the oqxA gene was higher in ciprofloxacin-resistant isolates.

Conclusion

The results of this study suggest a potential reservoir for the spread of OqxAB genes among hospital-acquired bacteria. Infection control strategies should be used prudently to reduce the spread of resistant strains of K. pneumoniae in hospitals.

Coagulation and hemolysis complications in neonatal ECLS: Role of devices

Neonatal extracorporeal life support (ECLS) has enjoyed a long history of successful patient support for both cardiac and respiratory failure. The small size of this patient population has provided many technical challenges from cannulation to pumps and oxygenators. This is further complicated by the relatively meager commercial options for equipment owing to the relatively low utilization of neonatal ECLS compared to adults, which has exploded following the H1N1 epidemic and the availability of the polymethylpentene oxygenator. This paper focuses on the impact of equipment choices on thrombosis and hemolysis in neonatal ECLS and the underlying mechanisms behind them. Based upon the available evidence, it is clear neonatal ECLS requires careful attention to the selection and operation of all parts of the ECLS system. Practitioners should also be aware of the factors that increase blood cell fragility, which can impact decisions around equipment and subsequent operation.

Functional assay of light-induced ion-transport by rhodopsins

Microbial rhodopsins are photoreceptive membrane proteins found from diverse microorganisms such as archaea, eubacteria, eukaryotes and viruses. Many microbial rhodopsins possess ion-transport activity by light, such as channels and pumps, and ion-transporting rhodopsins are important tools in optogenetics that control animal behavior by light. Historically, molecular mechanism of rhodopsins has been studied by spectroscopic methods for purified proteins. On the other hand, ion-transport function has to be studied by different methods. This chapter introduces two methods of functional assay of ion-transporting rhodopsins by light. One is a patch clamp method using mammalian cells, and another is an ion-transport assay using pH electrode and microbial cells. These functional assay provides fundamental data of ion-transporting rhodopsins, and thus contributes to evaluation for optogenetic tools.

Mini-review: pump therapy in endocrinology & metabolism beyond diabetes

The first pump developed by Dr. Kadish and his team in 1963 aimed to "continue subcutaneous insulin infusion". The number of patients using insulin pumps has increased since the 1980s. This historical perspective has labeled pump therapy in endocrinology and metabolism synonymous with insulin pumps. However, certain other hormonal disorders might also benefit from this kind of treatment. Pump therapy is currently the best approach to achieve physiological mimicry. Furthermore, it may help in overcoming pharmacokinetic issues or allergies. Until now, hormone replacement via pumps has been a salvage method for complex cases at the expense of increased costs. However, it is believed that applications of pump treatment will widen in the future owing to the rapidly evolving technology. In this mini review, data on pump use for patients with adrenal insufficiency, hypogonadism, hypoparathyroidism, congenital adrenal hyperplasia, and congenital hyperinsulinism have been briefly summarized. The study has aimed at covering all the relevant clinical studies and important case reports/series. METHODS: A systematic literature search has been conducted on PubMed database seeking articles published until May 2021 using a combination of the following Medical Subject Headings terms and keywords: pump "OR" continue infusion "AND" (adrenal insufficiency "OR" Addison "OR" hydrocortisone "OR" hypoparathyroidism "OR teriparatide" "OR" somatostatin "OR" hypogonadism "OR" hypoglycemia "OR" endocrinology "OR" hormone replacement). In addition, the reference publications in the identified articles have also been reviewed.

Teriparatide administration by the Omnipod pump: preliminary experience from two cases with refractory hypoparathyroidism

CONTEXT

Hypoparathyroidism (hypoPTH) in adults is mainly due to total thyroidectomy. Conventional therapies (calcium, active vitamin D) can fail to normalize calcemia, expose the patient to hypercalciuria and impact quality-of-life. Human parathormone (PTH) replacement therapy is a suitable option in these cases, although few clinical reports have been published so far.

METHODS

We describe two cases of patients with refractory postsurgical hypoPTH, in whom subcutaneous infusion of recombinant PTH (teriparatide) through the Omnipod® pump was initiated after failure of all other therapeutic options. Besides, we performed a review of literature of hypoPTH cases treated by continuous infusion of teriparatide.

RESULTS

Two women aged 46 and 61 years old failed to normalize calcemia either with conventional treatments (calcium 8 g/day + calcitriol 9 mcg/day and calcium 5 g/day + calcitriol 12 mcg/day) or with thrice daily subcutaneous injections of teriparatide. As a last resort, teriparatide infusion via Omnipod® device normalized their calcemia and allowed calcium/vitamin D withdrawal, with average teriparatide dose of 23 and 32 mcg/day, respectively. The flow of teriparatide was adapted according to a protocol based on measured calcemia, under medical supervision. In the literature, 15 adult cases (13 women, mean age 44.5 ± 5.2 years old) are reported. HypoPTH was consecutive to surgery in all of them. Mean dose of teriparatide administered was 25 ± 6 mcg/day with improvement of calcemia level and quality-of-life in all patients.

CONCLUSIONS

Continuous administration of teriparatide through Omnipod® appears as an efficient therapeutic option in refractory hypoPTH, whose administration to the patient can be assisted by medically-supervised protocol.

Dynamic left ventricular outflow tract gradient resulting from Takotsubo cardiomyopathy ameliorated by intra-aortic balloon pump counterpulsation: a case report

BACKGROUND

Takotsubo cardiomyopathy is a variant of acute coronary syndrome with characteristic acute left ventricular apical ballooning. Uncommonly, there can be associated left ventricular outflow tract (LVOT) obstruction causing cardiogenic shock refractory to inotropic support. The use of afterload-reducing mechanical support such as intra-aortic balloon pump (IABP) counterpulsation is not routinely employed in instances of this kind.

CASE SUMMARY

In our case report, we describe a 66-year-old female with acute Takotsubo cardiomyopathy and associated LVOT obstruction which failed to respond to high-dose dobutamine and whose clinical trajectory was worsened by fast atrial fibrillation with rapid ventricular response. Within 24 h of admission, the patient had an IABP placed which rapidly improved her haemodynamics. Two days later, IABP was removed and within 6 days of admission, apical ballooning and LVOT obstruction had fully recovered.

CONCLUSION

We recommend early use of mechanical support with IABP counterpulsation to expedite recovery in patients with acute Takotsubo cardiomyopathy with associated LVOT obstruction.

History and Perspectives of Ion-Transporting Rhodopsins

The first light-sensing proteins used in optogenetics were rhodopsins. The word "rhodopsin" originates from the Greek words "rhodo" and "opsis," indicating rose and sight, respectively. Although the classical meaning of rhodopsin is the red-colored pigment in our eyes, the modern meaning of rhodopsin encompasses photoactive proteins containing a retinal chromophore in animals and microbes. Animal and microbial rhodopsins possess 11-cis and all-trans retinal, respectively, to capture light in seven transmembrane α-helices, and photoisomerizations into all-trans and 13-cis forms, respectively, initiate each function. We are able to find ion-transporting proteins in microbial rhodopsins, such as light-gated channels and light-driven pumps, which are the main tools in optogenetics. In this chapter, historical aspects and molecular properties of rhodopsins are introduced. In the first part, "what is rhodopsin?", general introduction of rhodopsin is presented. Then, molecular mechanism of bacteriorodopsin, a light-driven proton pump and the best-studied microbial rhodopsin, is described. In the section of channelrhodopsin, the light-gated ion channel, molecular properties, and several variants are introduced. As the history has proven, understanding the molecular mechanism of microbial rhodopsins is a prerequisite for useful functional design of optogenetics tools in future.

Dataset for assessing the reliability of central heating station based units of buildings

This article contains data on equipment failures at thirty-six centralized heating stations. In the process of operation of heating stations, the arising failures can lead to a significant decrease in air temperature in heated rooms. Data was obtained through the study of operational logs. When analyzing the data, we used the records of a five-year observation period (2012 to 2017) taking into account the preventive work that carried out annually as part of the preparation of equipment for use in winter conditions. Malfunctions of equipment elements, that arise during the operation of heat supply stations, have different meanings in qualitative and quantitative aspects. Different specialists of the same qualification may not represent the same quality characteristics of the same shortcomings. The presentation of faults in the form of sequences of numbers allows to formalize the analysis and reduce the influence of the subjective factor. Data on observations of equipment failures and restoration are the basis for determining the equipment reliability indicators at heat supply stations. The data can be used for repair planning, emergency services, financial planning and operational management focus. The obtained data are related to the research article “Monitoring of heating systems as a factor of energy safety of buildings” [1].

Penile prosthesis surgery: Indications and penoscrotal approach

Inflatable penile prosthesis was developed in 1973 as a definitive treatment for erectile dysfunction. Since then these prosthetic devices underwent huge modifications, and scientific and technologic advances were accomplished, improving reliability, longevity and the surgical outcomes. Surgical implantation of a penile prosthesis may be considered in patients with erectile dysfunction who do not respond to pharmacotherapy or who prefer a permanent solution to their problem. According to the 2019 EAU Guidelines, regardless of the indication, prosthesis implantation has one of the highest satisfaction rates (92-100% in patients and 91-95% in partners) among the treatment options for erectile dysfunction based on appropriate consultation. The penoscrotal handling is the most common approach accounting for >80% of inflatable penile prosthesis placed worldwide. Most frequent complaints and dissatisfaction with inflatable penile prosthesis are related to technical issues or poor surgical outcomes such as the final length of the penis. There is an urgent need to improve the patient awareness in inflatable penile prosthesis in the preoperative arena, including the high expectation management, and an effort to select the proper patients for definitive treatment.

Cost comparison among punctate midline myelotomy, intrathecal pain pump, and spinal cord epidural stimulator

Background:

Invasive pain procedures can be valuable tools to manage chronic pain. Here, we compared the costs of three procedures used to address chronic pain; punctate midline myelotomy (PMM), placement of a spinal cord stimulator (SCS), or placement of an intrathecal pain pump (ITPP).

Case Description:

This retrospective chart review yielded 9 patients with chronic pain syndromes; 3 had PMM, 3 had SCS, and 3 had ITPP procedures. Variables studied included; pain type, the procedures performed, and the cost of each procedure. The Wilcoxon rank-sum and one-way analysis of variance were used to compare the three groups (P < 0.05). PMM was performed for patients with chronic nonmalignant visceral pain and SCS was utilized for failed back syndrome, while ITPP was placed in two patients with chronic visceral cancer pain and one patient with chronic somatic cancer pain. The mean length of stay was significant shorter for SCS and PMM versus ITPP (e.g., 1, 3.6 ± 0.6 and 15 ± 5.6 days). The mean procedure costs were significantly higher for SCS versus PMM and ITPP (105,234, $71,087, and $79,333); for the latter PMM and ITPP, procedural costs were not significantly different.

Conclusion:

For the three pain procedures discussed in this report, PMM is the most cost-effective as it obviates the need for efficacy trials, and there are: no implant device costs, no medication refills, no maintenance costs, and no complication management costs.

Biophysics of rhodopsins and optogenetics

Rhodopsins are photoreceptive proteins and key tools in optogenetics. Although rhodopsin was originally named as a red-colored pigment for vision, the modern meaning of rhodopsin encompasses photoactive proteins containing a retinal chromophore in animals and microbes. Animal and microbial rhodopsins respectively possess 11-cis and all-trans retinal, respectively. As cofactors bound with their animal and microbial rhodopsin (seven transmembrane α-helices) environments, 11-cis and all-trans retinal undergo photoisomerization into all-trans and 13-cis retinal forms as part of their functional cycle. While animal rhodopsins are G protein coupled receptors, the function of microbial rhodopsins is highly divergent. Many of the microbial rhodopsins are able to transport ions in a passive or an active manner. These light-gated channels or light-driven pumps represent the main tools for respectively effecting neural excitation and silencing in the emerging field of optogenetics. In this article, the biophysics of rhodopsins and their relationship to optogenetics are reviewed. As history has proven, understanding the molecular mechanism of microbial rhodopsins is a prerequisite for their rational exploitation as the optogenetics tools of the future.

Accuracy assessment of a PION TCI pump based on international standards

Background

Inaccuracies associated with target-controlled infusion (TCI) delivery systems are attributable to both software and hardware issues, as well as pharmacokinetic variability. However, little is known about the inaccuracy of the syringe pump operating in TCI mode. This study aimed to evaluate the accuracy of the TCI pump based on international standards.

Methods

A test apparatus for accuracy evaluation of a syringe pump (PION TCI^®, Bionet Co. Ltd.) was designed to apply the gravimetric method. Pump accuracy was evaluated in terms of deviation defined by the following equation: infusion rate deviation (%) = (Rate_mea - Rate_est ) / Rate_est × 100, where Rate_mea is the infusion rate (ml/h) as measured by the gravimetric system, and Rate_est is the infusion rate (ml/h) as estimated by the pump. An infusion rate representing TCI mode was determined from previous clinical trial data which evaluated the predictive performance of the pharmacokinetic model. The PION TCI pump used in that clinical trial was used to evaluate accuracy of the syringe pump. The distribution of infusion rates obtained from the clinical trial was calculated, and the median value of the distribution was determined as the representative value.

Results

The representative infusion rate representing TCI mode was 31 ml/h, at which the infusion rate deviation was 4.5 ± 1.6%.

Conclusions

The inaccuracy of the syringe pump contributing to TCI system inaccuracy is insignificant.

Left ventricular assist devices and their complications: A review for emergency clinicians

INTRODUCTION

End stage heart failure is associated with high mortality. However, recent developments such as the ventricular assist device (VAD) have improved patient outcomes, with left ventricular assist devices (LVAD) most commonly implanted.

OBJECTIVE

This narrative review evaluates LVAD epidemiology, indications, normal function and components, and the assessment and management of complications in the emergency department (ED).

DISCUSSION

The LVAD is a life-saving device in patients with severe heart failure. While first generation devices provided pulsatile flow, current LVAD devices produce continuous flow. Normal components include the pump, inflow and outflow cannulas, driveline, and external controller. Complications related to the LVAD can be divided into those that are LVAD-specific and LVAD-associated, and many of these complications can result in severe patient morbidity and mortality. LVAD-specific complications include device malfunction/failure, pump thrombosis, and suction event, while LVAD-associated complications include bleeding, cerebrovascular event, infection, right ventricular failure, dysrhythmia, and aortic regurgitation. Assessment of LVAD function, patient perfusion, and mean arterial pressure is needed upon presentation. Electrocardiogram and bedside ultrasound are key evaluations in the ED. LVAD evaluation and management require a team-based approach, and consultation with the LVAD specialist is recommended.

CONCLUSION

Emergency clinician knowledge of LVAD function, components, and complications is integral in optimizing care of these patients.

Impact of Insulin Injection and Infusion Routines on Lipohypertrophy and Glycemic Control in Children and Adults with Diabetes

INTRODUCTION

Proper insulin injection/infusion is essential to optimize insulin absorption and action. Guidelines on insulin injection techniques are available. Lipohypertrophy (LH) is a local complication of insulin therapy, which results in erratic absorption and impaired glycemic control.

METHODS

Children and adults with type 1 diabetes on insulin injection or infusion were enrolled in the study. Subjects were interviewed and filled in a questionnaire on injection/infusion routines. Sites of injection/infusion were examined by trained diabetes educators, and capillary HbA1c was obtained.

RESULTS

One hundred sixty-nine subjects (104 children) with type 1 diabetes were enrolled; 119 were on multiple daily injection (MDI) and 50 on insulin pump therapy. Seventy-two percent and 82% of children and adults, respectively, rotate site at every injection; 78% of pump users change infusion set and 74% rotate site at 2-3 days. Thirty-nine percent and 32% of children and adults had LH. HbA1c was lower in children and adults with no LH (P < 0.001). An association was seen between LH and rotation frequency in children (P = 0.026). LH was the most common skin complication in the MDI group, while nodules, allergy marks and hyperpigmentation were seen in pump users.

CONCLUSION

Proper injection/infusion routines impact glycemic control and skin health. Education and examination of injection sites remain a crucial part of diabetes management.

Application of 3C insulin pump system in combination with non-invasive ventilation in the treatment of a patient with type 2 diabetes and obstructive sleep apnea syndrome

We observed the curative effect of the 3C insulin system in combination with non-invasive ventilation in a patient with type 2 diabetes and obstructive sleep apnea syndrome (OSAS). The 3C insulin pump is a system of devices that closely monitors and effectively regulates blood glucose levels. Non-invasive ventilation has been shown to be an effective treatment for OSAS. A type 2 diabetes patient with concomitant OSAS was treated with a 3C insulin pump system for real-time continuous glucose monitoring and nocturnal non-invasive ventilation for OSAS. Treatment-induced diabetic remission with improved sleep and reduced hypoglycemic episodes was achieved. Therefore, the 3C insulin pump system, in combination with non-invasive ventilation, is an effective treatment for type 2 diabetes patients with concomitant OSAS.

SSM-Based Electrophysiology for Transporter Research

Functional characterization of transport proteins using conventional electrophysiology can be challenging, especially for low turnover transporters or transporters from bacteria and intracellular compartments. Solid-supported membrane (SSM)-based electrophysiology is a sensitive and cell-free assay technique for the characterization of electrogenic membrane proteins. Purified proteins reconstituted into proteoliposomes or membrane vesicles from cell culture or native tissues are adsorbed to the sensor holding an SSM. A substrate or a ligand is applied via rapid solution exchange. The electrogenic transporter activity charges the sensor, which is recorded as a transient current. The high stability of the SSM allows cumulative measurements on the same sensor using different experimental conditions. This allows the determination of kinetic properties including EC₅₀, IC₅₀, K_m, K_D, and rate constants of electrogenic reactions. About 100 different transporters have been measured so far using this technique, among them symporters, exchangers, uniporters, ATP-, redox-, and light-driven ion pumps, as well as receptors and ion channels. Different instruments apply this technique: the laboratory setups use a closed flow-through arrangement, while the commercially available SURFE²R N1 resembles a pipetting robot. For drug screening purposes high-throughput systems, such as the SURFE²R 96SE enable the simultaneous measurement of up to 96 sensors.

The use of foot pumps compression devices in the perioperative management of ankle fractures: Systematic review of the current literature

BACKGROUND

Ankle fractures account for 9% of all fractures seen in the United Kingdom. 15,000 of these fractures undergo operative fixation each year. Soft tissue swelling impacts on timing of fixation due to fears of infection and wound dehiscence. The use of arterio-venous foot pumps (AVFP) is increasing in this population although the evidence for their efficacy is unclear. In order to address this, we present an overview of the evidence for AVFP device use following ankle fracture.

METHODS

In September 2015 an electronic literature search was undertaken of studies comparing two or more methods of swelling reduction in patients with ankle fractures. Of 326 screened, 5 papers ultimately were included.

RESULTS

Two studies reported a statistically significant reduction in swelling (p=0.03) and (p=0.03 at 24 hours, p=0.05 at 48 hours) after using AVFP devices compared to the controls (leg elevation +/ ice therapy). Stockle et al. reported a greater reduction in the preoperative ankle, midfoot and forefoot circumference at 24 hours in their AVFP group (53% versus 32% and 10% in their continuous cryotherapy and cool pack cryotherapy groups respectively). Whereas, Rohner-Spengler et al. observed improved preoperative swelling reduction in patients treated with a multilayer compression bandage when compared to their AVFP group. Keehan et al. reported that time to surgery was considerably reduced in patients treated with an AVFP device, (2.3 days) compared to those treated with leg elevation (4.6 days) (p=0.02). Length of stay (LOS) was not influenced by any of the tested interventions.

CONCLUSIONS

AVFP devices have been shown to reduce time to surgery and degree of swelling before operative intervention better than other methods but the strength of evidence to support this remains poor.

drip method

Tacrolimus sorption to tubes was evaluated using pump and drip methods For tubes, polyvinylchloride (PVC)- and non-PVC-based (polyurethane [PU] and polyolefin [PO]) tubes were used. First, inner surface properties of tubes were analyzed using field emission scanning electron microscopy and X-ray photoelectron spectroscopy. Tacrolimus was quantitatively analyzed using high-performance liquid chromatography with UV detection. For kinetic sorption analysis, diluted tacrolimus to 10μg/mL was passed through 1-m-long tubes at 10mL/h. Samples were collected at 1-4h. The inner surface of PO-based tubes was relatively smooth and soft compared with those of PVC- and PU-based tubes. Atomic compositions of tubes matched chemical formulas of polymers excluding low-level impurity in PVC-based tubes. Tacrolimus was successfully analyzed and linearly determined at 2.5-20μg/mL. From both methods, PVC- and PO-based tubes exhibited the highest and the lowest (<10%) sorption levels to tacrolimus, respectively. Tacrolimus was stably delivered using the pump method. Results suggested that the pump method can estimate tacrolimus sorption in administration set tubes and evaluate other sorptional drugs used at low concentrations. PO-based tubes also have promising potential as an alternative for administration set tubes.

Physical activity and sedentary behavior levels in children and adolescents with type 1 diabetes using insulin pump or injection therapy - The importance of parental activity profile

In children and adolescents, treatments for type 1 diabetes (T1D) have recently evolved with the introduction of the insulin pump. However, little is known about how a pump is associated with physical activity (PA) patterns. The goal of the study was to examine the activity profile of Canadian children and adolescents with T1D according to their insulin treatment (pump vs. injections), as well as barriers to exercise and parental lifestyle habits. A self-administered questionnaire was completed by 188 subjects with T1D aged 6 to 17 and their parents at the endocrinology clinic of Sainte-Justine's University Hospital Center (Montreal, Canada). Sixty percent of patients used an insulin pump. There were no significant differences in any components of the PA profile, sedentary habits, and exercise barriers between subjects using injections and those using a pump. Fear of hypoglycemia was the main PA barrier in both treatment groups. A more diverse PA practice by parents was associated with more moderate-to-vigorous PA and less screen time in adolescents. In conclusion, type of treatment was not associated with more activity in pediatric patients with T1D and a varied parental PA profile was the main factor of interest for healthier habits in adolescents with T1D.

Nomenclature for renal replacement therapy and blood purification techniques in critically ill patients: practical applications

This article reports the conclusions of the second part of a consensus expert conference on the nomenclature of renal replacement therapy (RRT) techniques currently utilized to manage acute kidney injury and other organ dysfunction syndromes in critically ill patients. A multidisciplinary approach was taken to achieve harmonization of definitions, components, techniques, and operations of the extracorporeal therapies. The article describes the RRT techniques in detail with the relevant technology, procedures, and phases of treatment and key aspects of volume management/fluid balance in critically ill patients. In addition, the article describes recent developments in other extracorporeal therapies, including therapeutic plasma exchange, multiple organ support therapy, liver support, lung support, and blood purification in sepsis. This is a consensus report on nomenclature harmonization in extracorporeal blood purification therapies, such as hemofiltration, plasma exchange, multiple organ support therapies, and blood purification in sepsis.

Distribution and abundance of surface water microlitter in the Baltic Sea: A comparison of two sampling methods

Two methods for marine microlitter sampling were compared in the Gulf of Finland, northern Baltic Sea: manta trawl (333μm) and a submersible pump (300 or 100μm). Concentrations of microlitter (microplastics, combustion particles, non-synthetic fibres) in the samples collected with both methods and filter sizes remained <10particlesm(-3). The pump with 100μm filter gave higher microlitter concentrations compared to manta trawl or pump with 300μm filter. Manta sampling covers larger areas, but is potentially subjected to contamination during sample processing and does not give precise volumetric values. Using a submerged pump allows method controls, use of different filter sizes and gives exact volumetric measures. Both devices need relatively calm weather for operation. The choice of the method in general depends on the aim of the study. For monitoring environmentally relevant size fractions of microlitter the use of 100μm or smaller mesh size is recommended for the Baltic Sea.

Intrathecal Baclofen therapy in Germany: Proceedings of the IAB-Interdisciplinary Working Group for Movement Disorders Consensus Meeting

Continuous intrathecal Baclofen application (ITB) through an intracorporeal pump system is widely used in adults and children with spasticity of spinal and supraspinal origin. Currently, about 1200 new ITB pump systems are implanted in Germany each year. ITB is based on an interdisciplinary approach with neurologists, rehabilitation specialists, paediatricians and neurosurgeons. We are presenting the proceedings of a consensus meeting organised by IAB-Interdisciplinary Working Group for Movement Disorders. The ITB pump system consists of the implantable pump with its drug reservoir, the refill port, an additional side port and a flexible catheter. Non-programmable pumps drive the Baclofen flow by the reservoir pressure. Programmable pumps additionally contain a radiofrequency control unit, an electrical pump and a battery. They have major advantages during the dose-finding phase. ITB doses vary widely between 10 and 2000 μg/day. For spinal spasticity, they are typically in the order of 100-300 μg/day. Hereditary spastic paraplegia seems to require particularly low doses, while dystonia and brain injury require particularly high ones. Best effects are documented for tonic paraspasticity of spinal origin and the least effects for phasic muscle hyperactivity disorders of supraspinal origin. Oral antispastics are mainly effective in mild spasticity. Botulinum toxin is most effective in focal spasticity. Myotomies and denervation operations are restricted to selected cases of focal spasticity. Due to its wide-spread distribution within the cerebrospinal fluid, ITB can tackle wide-spread and severe spasticity.