Individualised optimisation of mechanical ventilation (MV) remains cumbersome in modern intensive care medicine. Computerised, model-based support systems could help in tailoring MV settings to the ...complex interactions between MV and the individual patient's pathophysiology. Therefore, we critically appraised the current literature on computational physiological models (CPMs) for individualised MV in the ICU with a focus on quality, availability, and clinical readiness.
A systematic literature search was conducted on 13 February 2023 in MEDLINE ALL, Embase, Scopus and Web of Science to identify original research articles describing CPMs for individualised MV in the ICU. The modelled physiological phenomena, clinical applications, and level of readiness were extracted. The quality of model design reporting and validation was assessed based on American Society of Mechanical Engineers (ASME) standards.
Out of 6,333 unique publications, 149 publications were included. CPMs emerged since the 1970s with increasing levels of readiness. A total of 131 articles (88%) modelled lung mechanics, mainly for lung-protective ventilation. Gas exchange (n = 38, 26%) and gas homeostasis (n = 36, 24%) models had mainly applications in controlling oxygenation and ventilation. Respiratory muscle function models for diaphragm-protective ventilation emerged recently (n = 3, 2%). Three randomised controlled trials were initiated, applying the Beacon and CURE Soft models for gas exchange and PEEP optimisation. Overall, model design and quality were reported unsatisfactory in 93% and 21% of the articles, respectively.
CPMs are advancing towards clinical application as an explainable tool to optimise individualised MV. To promote clinical application, dedicated standards for quality assessment and model reporting are essential. Trial registration number PROSPERO- CRD42022301715 . Registered 05 February, 2022.
Annually, about 8000 heart and lung transplantations are successfully performed worldwide. However, morbidity and mortality still pose a major concern. Renal failure in heart and lung transplant ...recipients is an essential adverse cause of morbidity and mortality, often originating in the early postoperative phase. At this time of clinical instability, the kidneys are exposed to numerous nephrotoxic stimuli. Among these, tacrolimus toxicity plays an important role, and its pharmacokinetics may be significantly altered in this critical phase by fluctuating drug absorption, changed protein metabolism, anemia and (multi‐) organ failure. Limited understanding of tacrolimus pharmacokinetics in these circumstances is hampering daily practice. Tacrolimus dose adjustments are generally based on whole blood trough levels, which widely vary early after transplantation. Moreover, whole blood trough levels are difficult to predict and are poorly related to the area under the concentration‐time curve. Even within the therapeutic range, toxicity may occur. These shortcomings of tacrolimus monitoring may not hold for the unbound tacrolimus plasma concentrations, which may better reflect tacrolimus toxicity. This review focuses on posttransplant tacrolimus pharmacokinetics, discusses relevant factors influencing the unbound tacrolimus concentrations and tacrolimus (nephro‐) toxicity in heart and lung transplantation patients.
Clinical instability early after heart and lung transplantation significantly changes tacrolimus pharmacokinetics, complicates dosing, and may increase unbound plasma concentration, potentiating nephrotoxicity and morbidity.
Recommendations of first choice antibiotic therapy need to be based on actual antibiotic susceptibility data. We determined the antibiotic susceptibility of
E. coli
in uncomplicated UTI among women ...and compared the results with 2004 and 2009. In 30 sentinel general practitioner practices of Nivel Primary Care database, urine samples were collected from women with symptoms of uncomplicated UTI. Patient characteristics,
E. coli
susceptibility, and ESBL production were analyzed. Six hundred eighty-nine urine samples were collected;
E. coli
was the most isolated uropathogen (83%). Antibiotic susceptibility was stable over time except for ciprofloxacin (96% in 2004, 97% in 2009, and 94% in 2014;
P
< 0.05). The susceptibility to co-amoxiclav was 88%, 87%, and 92% in 2004, 2009, and 2014, respectively. The prevalence of ESBL-producing
E. coli
increased from 0.1% in 2004 to 2.2% in 2014 (
P
< 0.05). Regional differences in antibiotic susceptibility for co-trimoxazole were found being the highest in the west (88%) and the lowest in the north (72%,
P
= 0.021). Ciprofloxacin susceptibility was related to antibiotic use in the past 3 months (97% no use versus 90% use,
P
= 0.002) and age > 70 years (
P
= 0.005). In 2014, prescription of fosfomycin increased compared to 2009 (14.3% versus 5.6%) at the expense of co-amoxiclav, co-trimoxazole, and fluoroquinolones (
P
< 0.05). The susceptibility percentages to most antimicrobial agents tested were stable over 10 years’ period although the prevalence of
E. coli
and ESBLs significantly increased. Performance of a survey with regular intervals is warranted.
Abstract Background Respiratory effort should be closely monitored in mechanically ventilated ICU patients to avoid both overassistance and underassistance. Surface electromyography of the diaphragm ...(sEMGdi) offers a continuous and non-invasive modality to assess respiratory effort based on neuromuscular coupling (NMCdi). The sEMGdi derived electrical activity of the diaphragm (sEAdi) is prone to distortion by crosstalk from other muscles including the heart, hindering its widespread use in clinical practice. We developed an advanced analysis as well as quality criteria for sEAdi waveforms and investigated the effects of clinically relevant levels of PEEP on non-invasive NMCdi. Methods NMCdi was derived by dividing end-expiratory occlusion pressure (Pocc) by sEAdi, based on three consecutive Pocc manoeuvres at four incremental (+ 2 cmH2O/step) PEEP levels in stable ICU patients on pressure support ventilation. Pocc and sEAdi quality was assessed by applying a novel, automated advanced signal analysis, based on tolerant and strict cut-off criteria, and excluding inadequate waveforms. The coefficient of variations (CoV) of NMCdi after basic manual and automated advanced quality assessment were evaluated, as well as the effect of an incremental PEEP trial on NMCdi. Results 593 manoeuvres were obtained from 42 PEEP trials in 17 ICU patients. Waveform exclusion was primarily based on low sEAdi signal-to-noise ratio (N tolerant = 155, 37%, N strict = 241, 51% waveforms excluded), irregular or abrupt cessation of Pocc (N tolerant = 145, 35%, N strict = 145, 31%), and high sEAdi area under the baseline (N tolerant = 94, 23%, N strict = 79, 17%). Strict automated assessment allowed to reduce CoV of NMCdi to 15% from 37% for basic quality assessment. As PEEP was increased, NMCdi decreased significantly by 4.9 percentage point per cmH 2 O. Conclusion Advanced signal analysis of both Pocc and sEAdi greatly facilitates automated and well-defined identification of high-quality waveforms. In the critically ill, this approach allowed to demonstrate a dynamic NMCdi (Pocc/sEAdi) decrease upon PEEP increments, emphasising that sEAdi-based assessment of respiratory effort should be related to PEEP dependent diaphragm function. This novel, non-invasive methodology forms an important methodological foundation for more robust, continuous, and comprehensive assessment of respiratory effort at the bedside.
Cardiac tamponade may present with very different signs and clinical consequences in patients who are supported with venoarterial extracorporeal membrane oxygenation. Failure to recognize cardiac ...tamponade in this setting can cause failure to wean from venoarterial extracorporeal membrane oxygenation, and even lead to death.
We present a 44-year-old Caucasian female in whom cardiac tamponade manifested as venoarterial extracorporeal membrane oxygenation weaning failure. After discovering the contribution of cardiac tamponade, it was possible to wean the patient from venoarterial extracorporeal membrane oxygenation support. No clear signs of cardiac tamponade had existed beforehand.
The diagnosis of cardiac tamponade can be very challenging in venoarterial extracorporeal membrane oxygenation supported patients due to (patho)physiological particularities related to the parallel blood flow.
Veno-arterial extracoporeal membrane oxygenation (VA ECMO) is increasingly used for acute and refractory cardiogenic shock. Yet, in clinical practice, monitoring of cardiac loading conditions during ...VA ECMO can be cumbersome. To this end, we illustrate the validity and clinical applicability of a real-time cardiovascular computer simulation, which allows to integrate hemodynamics, cardiac dimensions and the corresponding degree of VA ECMO support and ventricular loading in individual patients over time.
Short-term mechanical support by veno-arterial extracorporeal membrane oxygenation (VA ECMO) is more and more applied in patients with severe cardiogenic shock. A major shortcoming of VA ECMO is its ...variable, but inherent increase of left ventricular (LV) mechanical load, which may aggravate pulmonary edema and hamper cardiac recovery. In order to mitigate these negative sequelae of VA ECMO, different adjunct LV unloading interventions have gained a broad interest in recent years. Here, we review the whole spectrum of percutaneous and surgical techniques combined with VA ECMO reported to date.
Veno-arterial extracorporeal membrane oxygenation (VA ECMO) is widely used in cardiogenic shock. It provides systemic perfusion, but left ventricular (LV) unloading is suboptimal. Using a ...closed-loop, real-time computer model of the human cardiovascular system, cardiogenic shock supported by peripheral VA ECMO was simulated, and effects of various adjunct LV unloading interventions were quantified. After VA ECMO initiation (4 L/min) in cardiogenic shock (baseline), hemodynamics improved (increased to 85 mm Hg), while LV overload occurred (10% increase in end-diastolic volume EDV, and 5 mm Hg increase in pulmonary capillary wedge pressure PCWP). Decreasing afterload (65 mm Hg mean arterial pressure) and circulating volume (−800 mL) reduced LV overload (12% decrease in EDV and 37% decrease in PCWP) compared with baseline. Additional intra-aortic balloon pumping only marginally decreased cardiac loading. Instead, adjunct Impella™ enhanced LV unloading (23% decrease in EDV and 41% decrease in PCWP). Alternative interventions, for example, left atrial/ventricular venting, yielded substantial unloading. We conclude that real-time simulations may provide quantitative clinical measures of LV overload, depending on the degree of VA ECMO support and adjunct management. Simulations offer insights into individualized LV unloading interventions in cardiogenic shock supported by VA ECMO as a proof of concept for potential future applications in clinical decision support, which may help to improve individualized patient management in complex cardiovascular disease.
Extracorporeal life support (ECLS) is a mainstay of current practice in severe respiratory, circulatory or cardiac failure refractory to conventional management. The inherent complexity of different ...ECLS modes and their influence on the native pulmonary and cardiovascular system require patient-specific tailoring to optimize outcome. Echocardiography plays a key role throughout the ECLS care, including patient selection, adequate placement of cannulas, monitoring, weaning and follow-up after decannulation. For this purpose, echocardiographers require specific ECLS-related knowledge and skills, which are outlined here.
Background:
Initiation of veno-arterial (VA) Extracorporeal Membrane Oxygenator (ECMO) is associated with severe complications. It is unknown whether these adverse consequences occur more often after ...initiations during out of hours service compared to working hours.
Methods:
All patients receiving VA-ECMO for cardiogenic shock between 2009 and 2020 were categorized into a working hours group (between 8 am and 5 pm on weekdays) and an out of hours service group (between 5 pm and 8 am, or between Friday 5 pm and Monday 8 am). Primary outcome was all-cause mortality at 30 days. Secondary outcomes included vascular complications (including limb ischemia and/or bleeding), bloodstream infections and length of ICU stay. Propensity scores were used to adjust for potential confounding effects.
Results:
Among 250 patients (median (IQR) age 56 (42–64) years) receiving VA-ECMO (median duration 3.5 (1.0–9.0) days), 160 (64%) runs were initiated between 5 pm and 8 am whereas the remainder (36%) started during working hours. Characteristic did not differ between the working hours- and out of hours-group. By day 30, 37 (41.1%), and 68 (42.5%) patients in either group had died, respectively (p = 0.831). VA-ECMO support duration and length of stay on the ICU did not differ significantly in both crude and adjusted analyses. More complications occurred during out of hours service (p = 0.039).
Conclusions:
Out of hours- versus working hours-initiation of VA-ECMO for cardiogenic shock was not associated with higher mortality, longer VA-ECMO support duration, or longer length of stay on the intensive care. Vascular complications were more common in the out of hours group.
PDF
