Nardo van der Meer - Academia.edu (original) (raw)

Papers by Nardo van der Meer

Thrombosis Research, Jul 1, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Cardiothoracic and Vascular Anesthesia, Aug 1, 2017

Objectives: The Behavioral Pain Scale (BPS) and Critical-Care Pain Observation Tool (CPOT) are be... more Objectives: The Behavioral Pain Scale (BPS) and Critical-Care Pain Observation Tool (CPOT) are behavioral pain assessment tools for sedated and unconscious critically ill patients. The aim of this study was to compare the reliability, internal consistency, and discriminant validation of the BPS and the CPOT simultaneously in mechanically ventilated patients after cardiac surgery. Design: A prospective, observational cohort study. Setting: A 20-bed closed-format intensive care unit with mixed medical, surgical, and cardiac surgery patients in a teaching hospital in Amsterdam, The Netherlands. Participants: The study comprised 72 consecutive intubated and mechanically ventilated patients after cardiac surgery who were not able to selfreport pain. Measurements and Main Results: Two nurses assessed the BPS and CPOT simultaneously and independently at the following 4 moments: rest, a nonpainful procedure (oral care), rest, and a painful procedure (turning). Both scores showed a significant increase of 2 points between rest and turning. The median BPS score of nurse 1 showed a significant increase of 1 point between rest and the nonpainful procedure (oral care), whereas both median CPOT scores did not change. The interrater reliability of the BPS and CPOT showed fair-to-good agreement of 0.74 overall. During the periods of rest 1 and rest 2, values ranged from 0.24 to 0.46. Cronbach's alpha values for the BPS were 0.62 (nurse 1) and 0.59 (nurse 2) compared with 0.65 and 0.58, respectively, for the CPOT. Conclusions: The BPS and CPOT are reliable and valid pain assessment tools in a daily clinical setting. However, the discriminant validation of both scores seems less satisfactory in sedated or agitated patients and this topic requires further investigation.

Resuscitation, Mar 1, 2017

Angiology, Feb 1, 1999

In search for the origin of the less reliable cardiac output (CO) estimations by means of electri... more In search for the origin of the less reliable cardiac output (CO) estimations by means of electrical impedance cardiography (EIC), the authors hypothesized that cardiac valve pathology might be one of the reasons. Twenty-six patients were examined by means of echo Doppler (ED) and EIC. The cardiac valve status was obtained by means of echocardiography and color Doppler flow, while CO was obtained by means of both methods. Seventeen patients had no valve pathology (nVP) while nine patients had mild to moderate mitral regurgitation (MVR). The overall correlation between the calculation of CO by means of the two methods was good (r = 0.85, p &amp;amp;amp;amp;amp;amp;amp;lt; 0.001, mean difference and standard deviation: 0.20+/-0.74 L/min), while there was no significant difference between the paired values. After division into an nVP and an MVR population, the results showed an even closer agreement between the CO values in the nVP population (r = 0.88, p &amp;amp;amp;amp;amp;amp;amp;lt; 0.001, mean difference and standard deviation: 0.15+/-0.68 L/min). Furthermore, significant differences were found in the first derivative of the impedance (dZ/dt) signals of these groups. Although the agreement between ED and EIC was slightly lower in the MVR population, EIC reliably estimated CO, even in case of MVR. The impedance signal itself gave an indication for the existence of MVR.

BJA: British Journal of Anaesthesia, Apr 1, 2022

Previous studies have shown that preoperative anaemia in patients undergoing cardiac surgery is a... more Previous studies have shown that preoperative anaemia in patients undergoing cardiac surgery is associated with adverse outcomes. However, most of these studies were retrospective, had a relatively small sample size, and were from a single centre. The aim of this study was to analyse the relationship between the severity of preoperative anaemia and short- and long-term mortality and morbidity in a large multicentre national cohort of patients undergoing cardiac surgery. A nationwide, prospective, multicentre registry (Netherlands Heart Registration) of patients undergoing elective cardiac surgery between January 2013 and January 2019 was used for this observational study. Anaemia was defined according to the WHO criteria, and the main study endpoint was 120-day mortality. The association was investigated using multivariable logistic regression analysis. In total, 35 484 patients were studied, of whom 6802 (19.2%) were anaemic. Preoperative anaemia was associated with an increased risk of 120-day mortality (adjusted odds ratio [aOR] 1.7; 95% confidence interval [CI]: 1.4-1.9; P<0.001). The risk of 120-day mortality increased with anaemia severity (mild anaemia aOR 1.6; 95% CI: 1.3-1.9; P<0.001; and moderate-to-severe anaemia aOR 1.8; 95% CI: 1.4-2.4; P<0.001). Preoperative anaemia was associated with red blood cell transfusion and postoperative morbidity, the causes of which included renal failure, pneumonia, and myocardial infarction. Preoperative anaemia was associated with mortality and morbidity after cardiac surgery. The risk of adverse outcomes increased with anaemia severity. Preoperative anaemia is a potential target for treatment to improve postoperative outcomes.

Trials, May 9, 2018

Background: Evidence for benefit of high positive end-expiratory pressure (PEEP) is largely lacki... more Background: Evidence for benefit of high positive end-expiratory pressure (PEEP) is largely lacking for invasively ventilated, critically ill patients with uninjured lungs. We hypothesize that ventilation with low PEEP is noninferior to ventilation with high PEEP with regard to the number of ventilator-free days and being alive at day 28 in this population. Methods/Design: The "REstricted versus Liberal positive end-expiratory pressure in patients without ARDS" trial (RELAx) is a national, multicenter, randomized controlled, noninferiority trial in adult intensive care unit (ICU) patients with uninjured lungs who are expected not to be extubated within 24 h. RELAx will run in 13 ICUs in the Netherlands to enroll 980 patients under invasive ventilation. In all patients, low tidal volumes are used. Patients assigned to ventilation with low PEEP will receive the lowest possible PEEP between 0 and 5 cm H 2 O, while patients assigned to ventilation with high PEEP will receive PEEP of 8 cm H 2 O. The primary endpoint is the number of ventilator-free days and being alive at day 28, a composite endpoint for liberation from the ventilator and mortality until day 28, with a noninferiority margin for a difference between groups of 0.5 days. Secondary endpoints are length of stay (LOS), mortality, and occurrence of pulmonary complications, including severe hypoxemia, major atelectasis, need for rescue therapies, pneumonia, pneumothorax, and development of acute respiratory distress syndrome (ARDS). Hemodynamic support and sedation needs will be collected and compared. Discussion: RELAx will be the first sufficiently sized randomized controlled trial in invasively ventilated, critically ill patients with uninjured lungs using a clinically relevant and objective endpoint to determine whether invasive, low-tidal-volume ventilation with low PEEP is noninferior to ventilation with high PEEP.

Heart, Jan 30, 2020

This review provides an overview of the status of shared decision making (SDM) in older patients ... more This review provides an overview of the status of shared decision making (SDM) in older patients regarding treatment of symptomatic severe aortic stenosis (SSAS). The databases Embase, Medline Ovid, Cinahl and Cochrane Dare were searched for relevant studies from January 2002 to May 2018 regarding perspectives of professionals, patients and caregivers; aspects of decision making; type of decision making; application of the six domains of SDM; barriers to and facilitators of SDM. The systematic search yielded 1842 articles, 15 studies were included. Experiences of professionals and informal caregivers with SDM were scarcely found. Patient refusal was a frequently reported result of decision making, but often no insight was given into the decision process. Most studies investigated the ‘decision’ and ‘option’ domains of SDM, yet no study took all six domains into account. Problem analysis, personalised treatment aims, use of decision aids and integrating patient goals in decisions lacked in all studies. Barriers to and facilitators of SDM were ‘individualised formal and informal information support’ and ‘patients’ opportunity to use their own knowledge about their health condition and preferences for SDM’. In conclusion, SDM is not yet common practice in the decision making process of older patients with SSAS. Moreover, the six domains of SDM are not often applied in this process. More knowledge is needed about the implementation of SDM in the context of SSAS treatment and how to involve patients, professionals and informal caregivers.

The Journal of Thoracic and Cardiovascular Surgery, Apr 1, 2017

Objective: The study aim was to investigate the long-term prognosis and risk factors of postperic... more Objective: The study aim was to investigate the long-term prognosis and risk factors of postpericardiotomy syndrome (PPS). Methods: We performed a single-center cohort study in 822 patients undergoing nonemergent valve surgery. Risk factors of PPS were evaluated using multivariable logistic regression analysis. We also compared the incidence of reoperation for tamponade at 1 year between patients with and without PPS. Main secondary outcomes were hospital stay and mortality. Results: Of the 822 patients, 119 (14.5%) developed PPS. A higher body mass index (odds ratio (OR) per point increase, 0.94; 95% confidence interval (CI), 0.89-0.99) was associated with a lower risk of PPS, whereas preoperative treatment for pulmonary disease without corticosteroids (OR, 2.55; 95% CI, 1.25-5.20) was associated with a higher risk of PPS. The incidence of reoperation for tamponade at 1 year in PPS versus no PPS was 20.9% versus 2.5% (OR, 15.49; 95% CI, 7.14-33.58). One-year mortality in PPS versus no PPS was 4.2% versus 5.5% (OR, 0.68; 95% CI, 0.22-2.08). Median hospital stay was 13 days (interquartile range, 9-18 days) versus 11 days (interquartile range, 8-15 days) (P ¼ .001), respectively. Conclusions: Despite longer hospital stays and more short-term reoperations for tamponade, patients with PPS had an excellent 1-year prognosis.

International Journal of Cardiology, Mar 1, 2015

Background: Postoperative atrial fibrillation (AF) is a common complication after cardiac surgery... more Background: Postoperative atrial fibrillation (AF) is a common complication after cardiac surgery. Inflammation is believed to play a pivotal role in the etiology of postoperative AF. There is a suggestion from small studies that perioperative treatment with corticosteroids may reduce postoperative AF. The DExamethasone for Cardiac Surgery (DECS) study was a large randomized trial showing no protective effect of dexamethasone on major adverse events. The aim of this study was to investigate the effect of dexamethasone treatment on the occurrence of AF after cardiac surgery. Methods: The DECS study compared intra-operative dexamethasone (1 mg/kg) or placebo treatment in 4494 adult patients undergoing cardiac surgery. AF was defined by the occurrence of any reported AF within 30 days after surgery. We also performed an in-depth analysis of a subset of 1565 patients on new-onset AF. Relative risks (RRs) with 95% confidence intervals (CIs) were calculated. Results: The incidence of any AF in the main study of 4494 patients was 33.1% in the dexamethasone and 35.2% in the placebo group (RR 0.94, 95% CI: 0.87-1.02, p = 0.14). In the substudy of 1565 patients, the incidence of newonset AF was 33.0% vs. 35.5% (RR 0.93, 95% CI: 0.81-1.07, p = 0.31), respectively. There was no protective effect of dexamethasone across clinically important patient subgroups. Conclusion: Intraoperative administration of dexamethasone had no protective effect on the occurrence of any or

Kidney International, Oct 1, 1993

Non.invasive monitoring of blood volume during hemodialysis: Its relation with post-dialytic dry ... more Non.invasive monitoring of blood volume during hemodialysis: Its relation with post-dialytic dry weight. Hemodialysis has a profound effect on fluid balance. Since fluid is initially withdrawn from the intravascular compartment, blood volume will decrease rapidly. A fluid shift (refill) from the overhydrated interstitium towards the intravascular compartment counteracts hypovolemia. Underestimation of postdialytic dry weight will cause interstitial dehydration and consequently a low refill capacity. This can cause hypovolemia-induced hypotension, a serious problem in the daily practice of hemodialysis: during one out of three sessions a hypotensive episode occurs. Clinical criteria to estimate post-dialytic dry weight are insensitive. We have developed non-invasive methods to estimate dry weight and changes in blood volume (BY) more accurately. The aim of this study was to investigate the relation between hydration state of the patient and changes in BY during treatment. Therefore, 37 hemodialysis patients were divided into three groups according to their post-dialytic extracellular fluid volume (EFV), which was measured by means of the non-invasive conductivity method: de-(N = 11), normo-(N = 18), and overhydrated (N = 8). Using an on-line optical reflection method, changes in BY were measured continuously during hemodialysis. BY decrease, corrected for ultrafiltration, was stronger in the dehydrated (4.4 1 .5%/liter) than in the normohydrated (3.3 1.5%/liter) and overhydrated (2.7 1.9%/liter) groups. In the dehydrated group, the frequency of hypotensive episodes (48.5 20.2%) was significantly greater compared to the conductivity technique and BY was monitored continuously using an optical reflection method [12, 13] The ultimate aim was an early detection of hypovolemia in order to prevent hypotension. Methods

Frontiers in Microbiology

BackgroundSelective Decontamination of the Digestive tract (SDD) aims to prevent nosocomial infec... more BackgroundSelective Decontamination of the Digestive tract (SDD) aims to prevent nosocomial infections, by eradication of potentially pathogenic micro-organisms from the digestive tract.ObjectivesTo estimate the rate of and the time to eradication of resistant vs. susceptible facultative aerobic gram-negative bacteria (AGNB) in patients treated with SDD.MethodsThis observational and retrospective study included patients admitted to the ICU between January 2001 and August 2017. Patients were included when treated with SDD (tobramycin, polymyxin B, and amphotericin B) and colonized in the upper or lower gastro-intestinal (GI) tract with at least one AGNB present on admission. Decontamination was determined after the first negative set of cultures (rectal and throat). An additional analysis was performed of two consecutive negative cultures.ResultsOf the 281 susceptible AGNB in the throat and 1,087 in the rectum on admission, 97.9 and 93.7%, respectively, of these microorganisms were s...

Healthcare

In view of the shortage of medical staff, the quality and continuity of care may be improved by e... more In view of the shortage of medical staff, the quality and continuity of care may be improved by employing advanced practice providers (APPs). This study aims to assess the quality of these APPs in critical care. In a large teaching hospital, rapid response team (RRT) interventions led by APPs were assessed by independent observers and intensivists and compared to those led by medical residents MRs. In addition to mortality, the MAELOR tool (assessment of RRT intervention), time from RRT call until arrival at the scene and time until completion of clinical investigations were assessed. Process outcomes were assessed with the crisis management skills checklist, the Ottawa global rating scale and the Mayo high-performance teamwork scale. The intensivists assessed performance with the handoff CEX recipient scale. Mortality, MAELOR tool, time until arrival and clinical investigation in both groups were the same. Process outcomes and performance observer scores were also equal. The CEX re...

arXiv (Cornell University), Sep 14, 2021

Despite the recent progress in the field of causal inference, to date there is no agreed upon met... more Despite the recent progress in the field of causal inference, to date there is no agreed upon methodology to glean treatment effect estimation from observational data. The consequence on clinical practice is that, when lacking results from a randomized trial, medical personnel is left without guidance on what seems to be effective in a realworld scenario. This article proposes a pragmatic methodology to obtain preliminary but robust estimation of treatment effect from observational studies, to provide front-line clinicians with a degree of confidence in their treatment strategy. Our study design is applied to an open problem, the estimation of treatment effect of the proning maneuver on COVID-19 Intensive Care patients.

Intensive Care Medicine Experimental

Background The identification of risk factors for adverse outcomes and prolonged intensive care u... more Background The identification of risk factors for adverse outcomes and prolonged intensive care unit (ICU) stay in COVID-19 patients is essential for prognostication, determining treatment intensity, and resource allocation. Previous studies have determined risk factors on admission only, and included a limited number of predictors. Therefore, using data from the highly granular and multicenter Dutch Data Warehouse, we developed machine learning models to identify risk factors for ICU mortality, ventilator-free days and ICU-free days during the course of invasive mechanical ventilation (IMV) in COVID-19 patients. Methods The DDW is a growing electronic health record database of critically ill COVID-19 patients in the Netherlands. All adult ICU patients on IMV were eligible for inclusion. Transfers, patients admitted for less than 24 h, and patients still admitted at time of data extraction were excluded. Predictors were selected based on the literature, and included medication dosag...

Hygiene + Medizin, Mar 1, 2009

Heart, 2021

ObjectiveTo provide insight into professionals’ perceptions of and experiences with shared decisi... more ObjectiveTo provide insight into professionals’ perceptions of and experiences with shared decision-making (SDM) in the treatment of symptomatic patients with severe aortic stenosis (AS).MethodsA semistructured interview study was performed in the heart centres of academic and large teaching hospitals in the Netherlands between June and December 2020. Cardiothoracic surgeons, interventional cardiologists, nurse practitioners and physician assistants (n=21) involved in the decision-making process for treatment of severe AS were interviewed. An inductive thematic analysis was used to identify, analyse and report patterns in the data.ResultsFour primary themes were generated: (1) the concept of SDM, (2) knowledge, (3) communication and interaction, and (4) implementation of SDM. Not all respondents considered patient participation as an element of SDM. They experienced a discrepancy between patients’ wishes and treatment options. Respondents explained that not knowing patient preferenc...

Interactive CardioVascular and Thoracic Surgery, 2020

OBJECTIVES In cardiac surgery, adequate heparinization is necessary to prevent thrombus formation... more OBJECTIVES In cardiac surgery, adequate heparinization is necessary to prevent thrombus formation in the cardiopulmonary bypass (CPB). To counteract the heparin effect after weaning from CPB, protamine is administered. The optimal protamine/heparin ratio is still unknown. METHODS In this before–after study, we evaluated the effect of a 0.6/1-protamine/heparin ratio implementation as of May 2017 versus a 0.8/1-protamine/heparin ratio on the 12-h postoperative blood loss and the amount of blood and blood component transfusions (fresh frozen plasma, packed red blood cells, fibrinogen concentrate, platelet concentrate and prothrombin complex concentrate) after cardiac surgery. A total of 2051 patients who underwent cardiac surgery requiring CPB between May 2016 and May 2018 were included. RESULTS In the 0.6/1-protamine/heparin ratio group, only 28.8% of the patients received blood component transfusion, compared to 37.9% of the patients in the 0.8/1-ratio group (P < 0.001). The media...

Critical Care Explorations, 2020

Objective: To assess the frequency and safety of procedures performed by advanced practice provid... more Objective: To assess the frequency and safety of procedures performed by advanced practice providers and medical residents in a mixed-bed ICU. Design: A prospective observational study where consecutive invasive procedures were studied over a period of 1 year and 8 months. The interventions were registered anonymously in an online database. Endpoints were success rate at first attempt, number of attempts, complications, level of supervision, and teamwork. Setting: A 33-bedded mixed ICU. Subjects: Advanced practice providers and medical residents. Interventions: Registration of the performance of tracheal intubation, central venous and arterial access, tube thoracostomies, interhospital transportation, and electrical cardioversion. Measurement and Main Results: A full-time advanced practice provider performed an average of 168 procedures and a medical resident an average of 68. The advanced practice provider inserted significant more radial, brachial, and femoral artery catheters (66% vs 74%, p = 0.17; 15% vs 12%, p = 0.14; 18% vs 14%, p = 0.14, respectively). The median number of attempts needed to successfully insert an arterial catheter was lower, and the success rate at first attempt was higher in the group treated by advanced practice providers (1.30 [interquartile range, 1-1.82] vs 1.53 [interquartile range, 1-2.27], p < 0.0001; and 71% vs 54%, p < 0.0001). The advanced practice providers inserted more central venous catheters (247 vs 177) with a lower median number of attempts (1.20 [interquartile range, 1-1.71] vs 1.33 [interquartile range, 1-1.86]) and a higher success rate at first attempt (81% vs 70%; p < 0.005). The number of intubations by advanced practice providers was 143 and by medical residents was 115 with more supervision by the advanced practice provider (10% vs 0%; p = 0.01). Team performance, as reported by nursing staff, was higher during advanced practice provider procedures compared with medical resident procedures (median, 4.85 [interquartile range, 4.85-5] vs 4.73 [interquartile range, 4.22-5]). Other procedures were also more often performed by advanced practice providers. The complication rate in the advanced practice provider-treated patient group was lower than that in the medical resident group. Conclusions: Advanced practice providers in critical care performed procedures safe and effectively when compared with medical residents. Advanced practice providers appear to be a valuable addition to the professional staff in critical care when it comes to invasive procedures.

Anesthesiology, 2010

Thoracic epidural anesthesia is considered as an essential component of the perioperative care fo... more Thoracic epidural anesthesia is considered as an essential component of the perioperative care for patients undergoing lung resection. Although neurologic adverse events have been associated with this technique, permanent injury is rare. These events primarily involve the peripheral nervous system; for example, nerve root injury. We present a case of persistent cortical blindness after a test dose of bupivacaine was administered into an uneventfully placed thoracic epidural catheter.