An alternative ICU staffing model: implementation of the non-physician provider.

INTRODUCTION: Literature in Europe regarding implementation of nurse practitioners or physician assistants in the intensive care unit (ICU) is lacking, while some available studies indicate that this concept can improve the quality of care and overcome physician shortages on ICUs. The aim of this study is to provide insight on how a Dutch ICU implemented non-physician providers (NPP), besides residents, and what this staffing model adds to the care on the ICU. METHODS: This paper defines the training course and job description of NPPs on a Dutch ICU. It describes the number and quality of invasive interventions performed by NPPs, residents, and intensivists during the years 2015 and 2016. Salary scales of NPPs and residents are provided to describe potential cost-effectiveness. RESULTS: The tasks of NPPs on the ICU are equal to those of the residents. Analysis of the invasive interventions performed by NPPs showed an incidence of central venous catheter insertion for NPPs of 20 per fulltime equivalent (FTE) and for residents 4.3 per FTE in one year. For arterial catheters the NPP inserted 61.7 per FTE and the residents inserted 11.8 per FTE. The complication rate of both groups was in line with recent literature. Regarding their salary: after five years in service an NPP earns more than a starting resident. CONCLUSION: This is the first European study which describes the role of NPPs on the ICU and shows that practical interventions normally performed by physicians can be performed with equal safety and quality by NPPs.

Current practice of closed-loop mechanical ventilation modes on intensive care units - a nationwide survey in the Netherlands.

BACKGROUND: The most recent modes for mechanical ventilation are closed-loop modes, which are able to automatically adjust certain respiratory settings. Although closed-loop modes have been investigated in various clinical trials, it is unclear to what extent these modes are actually used in clinical practice. The aim of this study was to determine closed-loop ventilation practice on intensive care units (ICUs) in the Netherlands, and to explore reasons for not applying closed-loop ventilation. Our hypothesis was that closed-loop ventilation is increasingly used. METHODS: A short survey was conducted among all non-paediatric ICUs in the Netherlands. Use of closed-loop modes was classified as frequently, occasionally or never, if respondents stated they had used these modes in the last week, in the last month/year, or never, respectively. RESULTS: The response rate of the survey was 82% (72 of 88). Respondents had access to a closed-loop ventilation mode in 58% of the ICUs (42 of 72). Of these ICUs, 43% (18 of 42) frequently applied a closed-loop ventilation mode, while 57% (24 of 42) never or occasionally used it. Reasons for not using these modes were lack of knowledge (40%), insufficient evidence reporting a beneficial effect (35%) and lack of confidence (25%). CONCLUSION: This study does not support our hypothesis that closed-loop ventilation is increasingly used in the Dutch ICU setting. While industry continues to develop new closed-loop modes, implementation of these modes in clinical practice seems to encounter difficulties. Various barriers could play a role, and these all need attention in future investigations.

Approach to hypophosphataemia in intensive care units - a nationwide survey.

BACKGROUND: Evidence-based guidelines for monitoring of serum phosphate levels and for the treatment of hypophosphataemia in critically ill patients are lacking. The aim of this survey was to evaluate current practice with respect to diagnosis and treatment of hypophosphataemia in critically ill patients among intensive care unit (ICU) physicians in the Netherlands. METHODS: A survey was conducted among all hospitals with an ICU in the Netherlands. Paediatric ICUs were excluded from participation. A questionnaire was sent, with questions on practice regarding serum phosphate monitoring and treatment of hypophosphataemia. Respondents returned the questionnaire either by mail or through a web-based survey. RESULTS: A response was received from 67÷89 ICUs (75%). Respondents mentioned renal replacement therapy, sepsis and malnutrition, as well as surgery involving cardiopulmonary bypass as the most important causes of hypophosphataemia in intensive care unit patients. Of all respondents, 46% reported to measure serum phosphate levels on a daily basis, whereas in 12% serum phosphate levels were measured only on clinical indication. Less than half of the respondents had some sort of guideline for correction of hypophosphataemia. In a vast majority (79%), correction of hypophosphataemia was reported to start with serum phosphate levels.

Using a clinical decision support system to determine the quality of antimicrobial dosing in intensive care patients with renal insufficiency.

BACKGROUND: The benefits on clinical practice of a clinical decision support system (CDSS) are predominantly determined by the quality of the clinical rules used in this system. Therefore, it is essential to investigate the performance and potential benefits on quality of care of these rules. METHODS: A clinical rule assisting physicians in selecting the appropriate dosage according to renal function of frequently prescribed antimicrobials was developed. In 2004, 1788 patients admitted to the intensive care unit (ICU) for more than 12 h were included in this retrospective study. The actual number of dosage adjustments without the support of the CDSS was compared with the theoretical number of dosage adjustments determined by the clinical rule in patients with moderate (creatinine clearance (Cl(creat)) 10-50 ml/min) and severe (Cl(creat) <10 ml/min) renal dysfunction. If dosage adjustment was omitted, the duration of excessive anti-infective dosing and extra drug costs involved was determined. RESULTS: Dosage adjustment of antimicrobials was omitted in 163 patients (86%) with moderate renal failure and 13 patients (54%) with severe renal failure. Excessive exposure was most frequently detected in patients receiving fluconazole and ciprofloxacin (median duration of 6 days). In our ICU alone, more than 16,000 euro ($19 000) can be saved annually by adjusting the dosage according to renal function of frequently prescribed antimicrobials. CONCLUSIONS: Despite intensive monitoring of patients in the ICU, dosage adjustment of antimicrobials is often omitted. Implementing this clinical rule has the potential to contribute to a significant improvement in medication safety and is expected to generate substantial savings.

Right ventricular failure in acute respiratory distress syndrome.

Right ventricular failure can be the result of acute respiratory distress syndrome (ARDS). A patient with eclampsia and sepsis with Staphylococcus aureus developed life-threatening right ventricular failure as a result of ARDS. She finally stabilized after treatment with inhaled nitric oxide (NO). The pathophysiology of right ventricular failure in ARDS is described.

Predictive value of tetrapolar body impedance measurements for hydration status in critically ill patients.

OBJECTIVE: To design and evaluate a simple and rapid method to predict body hydration status in critically ill patients. DESIGN: Prospective, consecutive sample. SETTING: Medical intensive care unit of a university hospital. PATIENTS: 31 consecutive patients. METHODS: All patients were classified daily for hydration status by the attending physician based on clinical impression, weight changes and laboratory measurements. The hydration status was scored as 'dehydrated', 'euvolemic' or 'edematous'. The total body impedance was measured daily by a tetrapolar impedance technique. RESULTS: Resistances > 700 omega were found in dehydrated subjects and resistances of < 400 omega in edematous patients. Weight gain was observed in dehydrated and weight loss in edematous patients. A discriminant analysis was used to create a predictive model for hydration using the daily impedance and weight measurements. If a cutoff point of 60% for the predicted classification was used to categorize the patient's hydration as dehydrated, euvolemic and edematous, no false positive predictions were observed for the dehydrated or the edematous state. CONCLUSION: Impedance measurements are in close agreement with the clinical impression of hydration of critically ill patients. Future investigations must elucidate the clinical importance.

Chronic stimulation of atrial natriuretic peptide attenuates the secretory response to postural changes.

Atrial natriuretic peptide (ANP), released upon pulmonary vasoconstriction, modulates pulmonary vascular tone through an increase of cellular guanosine 3',5'-cyclic monophosphate. In patients with cardiopulmonary disease, however, the plasma levels of ANP are relatively low, considering the high pulmonary arterial pressure. To evaluate the release mechanism of the hormone, plasma ANP levels were studied by the manipulation of right atrial stretch with different body postures. In healthy young subjects, the plasma ANP concentration significantly increased when posture changed from an upright to a supine position (p < 0.01). In contrast, plasma ANP concentrations were significantly higher in patients with chronic obstructive pulmonary disease and elderly subjects (p < 0.01), but the plasma levels did not increase upon the change in posture. Consistent with in vitro findings, the data indicate that chronic ANP stimulation attenuates the secretory response to acute stimuli. In addition, it was demonstrated that the ratio of guanosine 3',5'-cyclic monophosphate to ANP, reflecting the biologic effect of the hormone, was significantly lower in patients with chronic obstructive pulmonary disease as well as in the elderly (p < 0.05). This decreased biologic activity aggravated the blunted ANP response and may contribute to the development of pulmonary hypertension.

Atrial natriuretic peptide improves pulmonary gas exchange in subjects exposed to hypoxia.

Atrial Natriuretic Peptide (ANP) is secreted in response to hypoxia and pulmonary vasoconstriction. The hormone modulates pulmonary vascular tone in vivo and decreases pulmonary edema in isolated lungs exposed to several toxic agents. In addition, ANP improves the barrier function of endothelial cell monolayers in vitro. The plasma levels of ANP are elevated in patients with high-altitude pulmonary edema. We hypothesized that under these circumstances, ANP improves pulmonary gas exchange by attenuating the transvascular permeation of plasma (water). Therefore, we studied the effect of low-dose ANP in 11 healthy mountaineers exposed to hypoxia in a single-blind, placebo-controlled, cross-over design. During four 1-h periods, the subjects were stepwise exposed to decreasing barometric pressure, with a minimum of 456 mm Hg (simulated altitude, 4,115 m). Infusion of 5 ng/kg/min human-ANP increased the plasma ANP concentrations approximately twofold. The plasma concentrations of cyclic GMP, which is the second messenger of ANP, rose approximately threefold. Infusion of ANP did not affect the hemodynamic or ventilatory response to hypoxia. The hemoglobin concentration, however, rose from 9.0 +/- 0.1 to 9.4 +/- 0.1 mmol/L (p < 0.01) during ANP infusion but not during placebo infusion. The change in plasma volume calculated from this hemoconcentration indicated that approximately 10% of the plasma volume had permeated into the interstitium. Despite the observed whole-body hemoconcentration, oxygen saturation was significantly higher during ANP infusion than during placebo infusion (84.7 +/- 1.7 versus 79.6 +/- 1.8%, p < 0.05), and the alveolar-arterial oxygen difference was significantly lower (3.5 +/- 0.7 versus 7.3 +/- 0.8 mm Hg, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of hypoxia and atrial natriuretic peptide on aldosterone secretion in healthy subjects.

To evaluate the inhibitory effect of hypoxia and atrial natriuretic peptide (ANP) on aldosterone secretion, 11 healthy male subjects were infused with 5 ng.kg-1 x min-1 ANP or placebo. The subjects were exposed in a stepwise fashion to incremental hypobaric hypoxia, which decreased arterial oxygen saturation to 79 +/- 2% in the placebo and 84 +/- 2% in the ANP condition (P < 0.05). In the placebo condition, the plasma ANP concentration increased from 13.8 +/- 1.0 to 19.6 +/- 2.3 pmol/l (P < 0.01) at the lowest barometric pressure. Plasma renin activity did not change, whereas the plasma aldosterone levels increased consequent to the increase of plasma adrenocorticotropic hormone (ACTH). Continuous infusion of ANP increased the plasma levels twofold (P < 0.001) and the level of guanosine 3',5'-cyclic monophosphate threefold (P < 0.001). However, the plasma aldosterone concentrations were not different in the two experimental conditions. Administration of supplementary oxygen significantly decreased ACTH to baseline values (P < 0.01) together with a decrease in aldosterone. Free water clearance (P = 0.05) but not sodium excretion (P = NS) increased during continuous ANP infusion. The data indicate that the aldosterone secretion in hypoxia is not inhibited by (patho)physiological plasma ANP levels. The inhibition of aldosterone secretion may well be explained by a direct effect of hypoxia on the adrenal cells. ACTH is a major stimulus of aldosterone secretion in hypoxia, which overrides the natriuretic effect of ANP.

Weight changes in critically ill patients evaluated by fluid balances and impedance measurements.

OBJECTIVE: To study simple, rapid, and predictive methods to determine body weight changes in critically ill patients. DESIGN: Prospective, consecutive sample. SETTING: Medical intensive care unit of a university hospital. PATIENTS: Thirty-one consecutive patients. INTERVENTIONS: Calculated weight changes, using day-to-day and cumulative fluid balances corrected (in two ways) for insensible losses, were compared with the actual weight changes (mattress bascule). A tetrapolar impedance technique measuring resistance was evaluated for estimating weight changes. MEASUREMENTS AND MAIN RESULTS: No reliable relationship was found between calculated weight changes using fluid balances corrected for insensible loss and the observed weight changes. An intraindividual relationship was found between actual weight changes and changes in resistance measured with the tetrapolar impedance technique in a group of 24 critically ill patients with large weight changes (11.1 +/- 6.7 kg). No such intraindividual relationship was found in seven patients with small weight changes (3.1 +/- 2.2 kg). In each patient, the slope coefficient of the change in weight and resistance relationship differed; this individual slope coefficient could be an indication for hydration. CONCLUSIONS: Calculated fluid balances are not predictive for actual weight changes in critically ill patients. Absolute weight measurements are indispensable. Changes in resistance correlated with weight changes in individual patients if weight changes were > 3 kg.

Preexisting cardiopulmonary disease attenuating the atrial natriuretic peptide response. Results in patients with acute respiratory failure.

The purpose of this study was to evaluate the pathophysiologic role of atrial natriuretic peptide (ANP) as a pulmonary artery vasodilator in patients with acute respiratory failure receiving artificial ventilation. Twenty-one consecutive patients were studied, 12 without and 9 with preexisting cardiopulmonary disease. Pulmonary artery plasma ANP levels were significantly higher than the levels obtained in the superior vena cava and radial artery. Plasma ANP levels correlated significantly with the plasma levels of its second messenger, guanosine 3',5'-cyclic monophosphate (cGMP). In the 12 patients without prior cardiopulmonary disease, plasma ANP levels correlated significantly with mean pulmonary arterial pressure (MPAP). This correlation was not found in the nine patients with preexisting cardiopulmonary disease. The cGMP/ANP ratio, indicating the biologic effect of ANP, was also higher in the patients without preexisting cardiopulmonary disease. These results are compatible with clearance and vasodilator activity of ANP in the pulmonary vascular bed, but only in patients without preexisting cardiopulmonary disease.

Tetrapolar body impedance is influenced by body posture and plasma sodium concentration.

Tetrapolar body impedance measures body resistance, which is highly correlated to total body water and fat-free mass. We investigated the change in resistance measured with tetrapolar impedance, resulting from fluid shifts, following an altered body posture and changes in resistance following an altered electrolyte composition of the extracellular fluid during hypertonic saline and mannitol infusion. An increase in body resistance was measured during recumbency, which was positively correlated with the calculated shift of interstitial fluid to the intravascular space. This effect was completely abolished after 5 min in the upright position. During infusion of 5% saline or 20% mannitol the change in resistance and the change in plasma sodium concentration were inversely correlated. Therefore the measurement of resistance is essentially influenced by alterations in the amount and composition of extracellular fluids. Using the resistance measurements standardization is obligatory for posture and plasma sodium concentration. This is particularly important when repeated measurements are performed.

Plasma atrial natriuretic peptide concentrations in patients weaning from positive-pressure ventilation.

The effect of positive-pressure ventilation on plasma atrial natriuretic peptide (ANP) concentrations was investigated in sixteen patients weaning from the ventilator. During spontaneous ventilation plasma ANP concentrations rose significantly from 59 (16-270) to 67 (13-320) pg/ml (median and range, P less than 0.05) and mean arterial blood pressure rose from 84 +/- 3 to 92 +/- 3 mmHg (mean +/- SEM, P less than 0.05) if compared with periods of positive-pressure ventilation. This increase in plasma ANP concentrations occurred irrespective of the underlying disease and the wide scatter of the ANP plasma levels found in individual patients. As right atrial stretch is the major stimulus for the release of the ANP the data indicate a decrease in cardiac output during positive-pressure ventilation following an impaired central venous return to the heart.

Does an insulin pen improve the metabolic control of type 1 diabetes mellitus if added to conventional treatment?

This study concerns the metabolic control of 19 type 1 diabetic patients during 3 consecutive periods of 4 months. All patients were well trained in self-control and self-regulation. During the first period, the previous treatment regimen consisting of diet and injections once or twice daily of short-acting and intermediate-acting insulin was intensified. During the 2nd period, an insulin pen, filled with short-acting insulin, was added to the treatment. The patients were advised to use this pen every time the blood glucose concentration exceeded 10 mmol/l or when this was expected; extra attention was paid to the lunch time and afternoon snacks. During the 3rd period, the use of the insulin pen was stopped but, just as in the 1st period, adjustments with short-acting insulin using normal syringes were allowed. The total daily dose of insulin remained unchanged throughout the entire study. The relative proportion of short-acting insulin increased from 25 to 34%, a quarter of which was injected by the insulin pen during period 2. The HbA1 % decreased steadily from 12.8 +/- 2.0 to 10.6 +/- 1.3 (P less than 0.001) during the first 2 periods and remained unchanged thereafter. The blood glucose concentration measured 7 times during the day twice monthly showed the greatest fall during the 1st period with only a minor extra fall during the 2nd period, and no further statistical drop during the last period. None of the patients had any problems using the insulin pen and 15 of 19 patients resumed its use after the end of the study. It is concluded that the improvement of glycaemic control was due to the intensified attention and not to the use of the insulin pen per se.