Willem Dieperink

Treatment of presumed acute cardiogenic pulmonary oedema in an ambulance system by nurses using Boussignac continuous positive airway pressure.

Background: Early initiation of continuous positive airway pressure (CPAP) applied by face mask benefits patients with acute cardiogenic pulmonary oedema (ACPE). The simple disposable Boussignac CPAP (BCPAP) has been used in ambulances by physicians. In the Netherlands, ambulances are manned by nurses and not physicians. It was hypothesised that ambulance nurses are able to identify patients with ACPE and can successfully apply BCPAP. A prospective case series of patients with presumed ACPE treated with BCPAP by ambulance nurses is described. Methods: After training of ambulance nurses, all 33 ambulances in the region were equipped with BCPAP. ACPE was diagnosed on clinical signs and pulse oximetry saturation (Spo2) <95%. BCPAP (5 cm H2O, Fio2 >80%) was generated with an oxygen flow of 15 l/min. The physiological responses, experiences and clinical outcomes of the patients were collected from ambulance and hospital records, and ambulance nurses and patients received a questionnaire. Results: From March to December 2006, 32 patients (age range 61–94 years) received BCPAP during transport to six different regional hospitals. In 26 patients (81%) a diagnosis of ACPE was confirmed. With BCPAP, median (IQR) Spo2 increased from 79% (69–94%) to 96% (89–98%) within 20 min. The median (IQR) duration of BCPAP treatment was 26 min (21–32). The patients had no negative recollections of the treatment. Ambulance personnel were satisfied with the BCPAP therapy. Conclusion: When applied by ambulance nurses, BCPAP was feasible and effective in improving oxygen saturation in patients with ACPE. Although survival benefit can only be demonstrated by further research, it is considered that BCPAP can be implemented in all ambulances in the Netherlands.

The effect of chronotype on sleepiness, fatigue, and psychomotor vigilance of ICU nurses during the night shift.

PurposeIn general, sleeping and activity patterns vary between individuals. This attribute, known as chronotype, may affect night shift performance. In the intensive care unit (ICR), night shift performance may impact patient safety. We have investigated the effect of chronotype and social demographics on sleepiness, fatigue, and night shift on the performance of nurses.MethodsThis was a prospective observational cohort study which assessed the performance of 96 ICU night shift nurses during the day and night shifts in a mixed medical–surgical ICU in the Netherlands. We determined chronotype and assessed sleeping behaviour for each nurse prior to starting shift work and before free days. The level of sleepiness and fatigue of nurses during the day and night shifts was determined, as was the effect of these conditions on psychomotor vigilance and mathematical problem-solving.ResultsThe majority of ICU nurses had a preference for early activity (morning chronotype). Compared to their counterparts (i.e. evening chronotypes), they were more likely to nap before commencing night shifts and more likely to have young children living at home. Despite increased sleepiness and fatigue during night shifts, no effect on psychomotor vigilance was observed during night shifts. Problem-solving accuracy remained high during night shifts, at the cost of productivity.ConclusionsMost of the ICU night shift nurses assessed here appeared to have adapted well to night shift work, despite the high percentage of morning chronotypes, possibly due to their 8-h shift duration. Parental responsibilities may, however, influence shift work tolerance.

Boussignac continuous positive airway pressure for the management of acute cardiogenic pulmonary edema: prospective study with a retrospective control group

BackgroundContinuous positive airway pressure (CPAP) treatment for acute cardiogenic pulmonary edema can have important benefits in acute cardiac care. However, coronary care units are usually not equipped and their personnel not adequately trained for applying CPAP with mechanical ventilators. Therefore we investigated in the coronary care unit setting the feasibility and outcome of the simple Boussignac mask-CPAP (BCPAP) system that does not need a mechanical ventilator.MethodsBCPAP was introduced in a coronary care unit where staff had no CPAP experience. All consecutive patients transported to our hospital with acute cardiogenic pulmonary edema, a respiratory rate > 25 breaths/min and a peripheral arterial oxygen saturation of < 95% while receiving oxygen, were included in a prospective BCPAP group that was compared with a historical control group that received conventional treatment with oxygen alone.ResultsDuring the 2-year prospective BCPAP study period 108 patients were admitted with acute cardiogenic pulmonary edema. Eighty-four of these patients (78%) were treated at the coronary care unit of which 66 (61%) were treated with BCPAP. During the control period 66 patients were admitted over a 1-year period of whom 31 (47%) needed respiratory support in the intensive care unit. BCPAP treatment was associated with a reduced hospital length of stay and fewer transfers to the intensive care unit for intubation and mechanical ventilation. Overall estimated savings of approximately € 3,800 per patient were achieved with the BCPAP strategy compared to conventional treatment.ConclusionAt the coronary care unit, BCPAP was feasible, medically effective, and cost-effective in the treatment of acute cardiogenic pulmonary edema. Endpoints included mortality, coronary care unit and hospital length of stay, need of ventilatory support, and cost (savings).

Intensive care unit depth of sleep: Proof of concept of a simple electroencephalography index in the non-sedated

IntroductionIntensive care unit (ICU) patients are known to experience severely disturbed sleep, with possible detrimental effects on short- and long- term outcomes. Investigation into the exact causes and effects of disturbed sleep has been hampered by cumbersome and time consuming methods of measuring and staging sleep. We introduce a novel method for ICU depth of sleep analysis, the ICU depth of sleep index (IDOS index), using single channel electroencephalography (EEG) and apply it to outpatient recordings. A proof of concept is shown in non-sedated ICU patients.MethodsPolysomnographic (PSG) recordings of five ICU patients and 15 healthy outpatients were analyzed using the IDOS index, based on the ratio between gamma and delta band power. Manual selection of thresholds was used to classify data as either wake, sleep or slow wave sleep (SWS). This classification was compared to visual sleep scoring by Rechtschaffen & Kales criteria in normal outpatient recordings and ICU recordings to illustrate face validity of the IDOS index.ResultsWhen reduced to two or three classes, the scoring of sleep by IDOS index and manual scoring show high agreement for normal sleep recordings. The obtained overall agreements, as quantified by the kappa coefficient, were 0.84 for sleep/wake classification and 0.82 for classification into three classes (wake, non-SWS and SWS). Sensitivity and specificity were highest for the wake state (93% and 93%, respectively) and lowest for SWS (82% and 76%, respectively). For ICU recordings, agreement was similar to agreement between visual scorers previously reported in literature.ConclusionsBesides the most satisfying visual resemblance with manually scored normal PSG recordings, the established face-validity of the IDOS index as an estimator of depth of sleep was excellent. This technique enables real-time, automated, single channel visualization of depth of sleep, facilitating the monitoring of sleep in the ICU.

Preventable mortality evaluation in the ICU

Mortality is the most widely measured outcome parameter. Improvement of this outcome parameter in critical care is nowadays expected not to come from new technologies or treatment, but from delivering the right care at the right moment in a safe way. The measurement of mortality as an outcome parameter confronts us with a problem in providing follow-up to the results. Especially when proven structure and process interventions are applied already, the cause of a suboptimal performance cannot be deduced easily. One possibility is to evaluate the causes of death and to judge preventability. In this article we explore the opportunities and difficulties of a tool to evaluate preventable mortality in the ICU.

Boussignac Continuous Positive Airway Pressure for Weaning with Tracheostomy Tubes

Background: In patients who are weaned with a tracheostomy tube (TT), continuous positive airway pressure (CPAP) is frequently used. Dedicated CPAP systems or ventilators with bulky tubing are usually applied. However, CPAP can also be effective without a ventilator by the disposable Boussignac CPAP (BCPAP) system that is normally used with face masks. Objective:It was the aim of this audit to evaluate the feasibility of low-level BCPAP in patients who were weaned with a TT. Methods: All patients at our surgical intensive care unit who received a TT for weaning were considered for application of BCPAP. Once patients had received minimal pressure support from the mechanical ventilator, the BCPAP device was connected to the TT three times a day for 30 min with pressure set to 3–5 cm H2O, FiO2 at 0.4 and with humidification. BCPAP was then gradually extended to 24 h/day. Patient acceptance, complications and outcome were recorded. Results: 58 patients received a TT to facilitate weaning. They had a median stay of 52 days in the intensive care unit during which they had an endotracheal tube for 22 days and a TT for 28 days. 50 of these patients (86%) received BCPAP for a median of 16 days. The lightweight BCPAP system was well tolerated without tube obstructions or accidental decannulations and may have contributed to patient mobility. No patient remained on ventilatory support after hospital discharge. In-hospital and 1-year survival were 86 and 71%, respectively. Conclusions: BCPAP is a feasible and safe method for weaning tracheostomy patients.

Target attainment with continuous dosing of piperacillin/tazobactam in critical illness: a prospective observational study

Optimal dosing of β-lactam antibiotics in critically ill patients is a challenge given the unpredictable pharmacokinetic profile of this patient population. Several studies have shown intermittent dosing to often yield inadequate drug concentrations. Continuous dosing is an attractive alternative from a pharmacodynamic point of view. This study evaluated whether, during continuous dosing, piperacillin concentrations reached and maintained a pre-defined target in critically ill patients. Adult patients treated with piperacillin by continuous dosing in the intensive care unit of a university medical centre in The Netherlands were prospectively studied. Total and unbound piperacillin concentrations drawn at fixed time points throughout the entire treatment course were determined by liquid chromatography-tandem mass spectrometry. A pharmacokinetic combined target of a piperacillin concentration ≥80 mg/L, reached within 1 h of starting study treatment and maintained throughout the treatment course, was set. Eighteen patients were analysed. The median duration of monitored piperacillin treatment was 60 h (interquartile range, 33-96 h). Of the 18 patients, 5 (27.8%) reached the combined target; 15 (83.3%) reached and maintained a less strict target of >16 mg/L. In this patient cohort, this dosing schedule was insufficient to reach the pre-defined target. Depending on which target is to be met, a larger initial cumulative dose is desirable, combined with therapeutic drug monitoring.

Real-time information on preventable death provided by email from frontline intensivists: results in high response rates with useful information

Recently, Provenzano et al 1 found that an electronic tool collecting real-time clinical information directly from frontline providers was both feasible and useful to evaluate inpatient deaths. These findings concur with our evaluation of the preventability of death using a simple electronic evaluation tool in our 46-bed adult intensive care unit (ICU). From September 2010 to September 2011, an email was sent to the attending intensivist each time a patient died in our intensive care including two questions: “Was this death preventable? If yes, what was the cause of preventability?” The definition of preventable …

Combination of heliox and CPAP without a ventilator: bench test and clinical observations

EDITOR: Failure to restore an adequate airway in patients with acute upper airway obstruction can rapidly lead to hypoxic injury or even death. Helium–oxygen mixtures (heliox) are less dense than air–oxygen mixtures and can improve the flow of gas through partially obstructed airways. Since Barach described this principle 70 years ago, heliox has at times been applied in spontaneously breathing patients with acute upper airways obstruction [1]. Heliox has also been combined with (non-) invasive mechanical ventilation, often with specifically adapted apparatus [2]. However, the correct function of ventilators relies on the precise measurement of flow, pressure, temperature and oxygen fraction for which the necessary sensors are calibrated for use with air–oxygen. The unique physical properties of heliox have an important impact on all these measurements. Thus the correct application of heliox in ventilators is far from trivial [3]. This technical problem becomes especially relevant under emergency circumstances. Continuous positive airway pressure (CPAP) by face mask can reduce upper airway collapse [4] and the combination of mask CPAP and heliox might be useful. The Boussignac continuous positive airway pressure (BCPAP) system (Vygon, 95440 Ecouen, France) for mask CPAP is a simple and lightweight (10 g) disposable plastic device without moving parts [5]. This device may thus avoid the problems with ventilators and heliox. In a bench test, we evaluated whether heliox works with the BCPAP system and how much more heliox flow was needed compared to oxygen to achieve similar pressures. We then evaluated the effect of this combination in selected patients with acute upper airways obstruction. We chose a helium–oxygen mixture of 60/40 to ensure a sufficient oxygen delivery under all circumstances. For the bench test we used 10 randomly selected, commercially available BCPAP systems and an analyser specifically designed to measure pressure or flow for helium–oxygen mixtures (VT Plus, Fluke Biomedical, Carson City, NV, USA). Since the variable orifice flow meters mounted on the heliox cylinders were oxygen-calibrated, we first recalibrated these meters by comparing the indicated flow of oxygen or heliox with the true flow as measured with the VTplus analyser. This was done 10 times for each of the following levels of indicated flow: 5, 10, 15, 20, 25 and 30 L min. The observed relation between indicated and actual flow was also compared to the theoretically predicted flow [6]. After this flowcalibration, we then measured the pressures generated by the BCPAP system for the various indicated flows (Fig. 1). The measured flow rates (true flow) of the variable orifice flow meters showed a 25 6 6% (SD) higher flow for heliox compared to oxygen. When we calculated the predicted actual flow for the variable orifice flow meters for heliox 60/40 based on

Cardiac rehabilitation for patients having cardiac surgery: a systematic review

INTRODUCTION Cardiac rehabilitation (CR) is recommended for all cardiac patients including patients after cardiac surgery. Since the effect of CR after cardiac surgery has not been well established yet, we conducted a systematic review on the effects of CR for patients after cardiac surgery compared to treatment as usual. EVIDENCE ACQUISITION A systematic review of randomized clinical trials (RCTs), quasi-randomized and prospective observational studies in The Cochrane Library, PubMed/MEDLINE and EMBASE was undertaken until October 18th, 2017. Adults after any kind of cardiac surgery were included. Primary outcome was all-cause mortality, other outcomes were serious adverse events, health-related quality of life, work participation, functioning and costs/cost-effectiveness. Risk of bias was evaluated, and the quality of evidence was assessed by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria. EVIDENCE SYNTHESIS Eighteen RCTs and 15 observational studies were included. Low risk of bias was only observed in one observational study. Meta-analysis of RCTs suggested no significant difference of CR compared to control on mortality (random-effects relative risk (RR) 0.93 (95% CI: 0.40-1.81), while observational studies suggested statistically significant beneficial effect associated with CR (random-effects RR=0.49, 95% CI: 0.35 - 0.68). CR did not significantly affect any of the other outcomes. Due to the limited data TSA could not be performed. CONCLUSIONS The body of evidence does not allow us to reach any reliable conclusions about the effectiveness of CR following cardiac surgery. Future trials need to be conducted with low risks of bias and clearly defined outcomes.