The venous–arterial difference in CO<Subscript>2</Subscript> should be interpreted with caution in case of respiratory alkalosis in healthy volunteers

The venous–arterial difference in CO₂ (ΔCO₂) has been proposed as an index of the adequacy of tissue perfusion in shock states. We hypothesized that the variation in PaCO₂ (hyper- or hypocapnia) could impact ΔCO₂, partly through microcirculation adaptations. Fifteen healthy males volunteered to participate. For hypocapnia condition (hCO₂), the subjects were asked to hyperventilate, while they were asked to breathe a gas mixture containing 8 % CO₂ for hypercapnia condition (HCO₂). The 2 conditions were randomly assigned. Blood gases were measured at baseline before each condition, and after 5–7 min of either hCO₂ or HCO₂ condition. Microcirculation was assessed by the muscle reoxygenation slope measured with near infrared spectroscopy following a vascular occlusion test and by skin circulation with in vivo reflectance confocal microscopy. ΔCO₂ was significantly increased with hCO₂ while it tended to decrease with HCO₂ (non-significant). HCO₂ induced a moderate increase of the resaturation slope of NIRS oxygenation. Skin microcirculatory blood flow significantly dropped with hCO₂, while it remained unchanged with hypercapnia. Our results warrant cautious interpretation of ΔCO₂ as an indicator of tissue perfusion during respiratory alkalosis.     

How do changes in exhaled CO<Subscript>2</Subscript> measure changes in cardiac output? A numerical analysis model

Objective  

In a previous study in anesthetized animals, the slope of percent decreases in exhaled CO₂ versus percent decreases in cardiac output ( [(Q)\dot]\scT, \dot{\rm Q}{\sc{T,}} inflation of vena cava balloons) was 0.73. To examine the mechanisms underlying this exhaled CO₂- [Q\dot]\sc T {\dot{\hbox{Q}}{\sc T}} relationship, an iterative numerical analysis computer model of non-steady state CO₂ kinetics was developed.     

‘Caught in the middle’? Mental nurse training in England 1919–51

The early history of mental health nurse training is one that has only been partially researched. While some writers have discussed the content and impact of training on the development of mental health nursing, little has been written on the professional and institutional factors that influenced this development. The medical profession, psychiatry, was to play an important role in the development of training and regulation of nursing staff in the large Victorian asylums and was an important influence on the knowledge base of mental health nursing. Their professional organization, the Medico-Psychological Association (the Royal Medico-Psychological Association after 1926 when they acquired a royal prefix) produced the first textbook for asylum nurses in 1885 and established a national training scheme for them 4 years later. However, in 1919 the Nurses Registration Act established the General Nursing Council for England and Wales and this body was given statutory responsibility for the training and registration of nurses, including 'mental' nurses. They were soon to be in conflict with the Medico-Psychological Association. The two organizations continued to run their own rival training schemes for mental health nurses for over 30 years, the Royal Medico-Psychological Association finally relinquishing their role in 1951. The Royal Medico-Psychological Association scheme proved far more popular than the General Nursing Councils, with significantly more nurses participating in it. This paper discusses these organizational influences on the development of 'mental nurse' training and discusses the possible impact that they have had on the knowledge base of mental health nursing.     

Medical hegemony in decision‐making – a barrier to interdisciplinary working in intensive care?

BACKGROUND: Health care policy in the United Kingdom identifies the need for health professionals to find new ways of working to deliver patient-focussed and economic care. Much debate has followed on the nature of working relationships within the health care team. AIM: This paper reports on an ethnographic study that examined the nursing role in clinical decision-making in intensive care units. This was chosen as a case for analysis due to the close doctor-nurse relationships that are essential in this acute and complex care setting. METHODS: Data were collected during two-stages of fieldwork using participant observation, in-depth ethnographic interviews and documentation across three clinical sites. FINDINGS: The findings revealed the different types of knowledge used for, divergence of roles involved in and degree of authority in clinical decision-making. Furthermore, conflict arose between doctors and nurses due to these differences and in particular because medicine dominated the decision-making process. CONCLUSIONS: The nursing role, whilst pivotal to implementing clinical decisions, remained unacknowledged and devalued. Medical hegemony continues to render nurses unable to influence substantially the decision-making process. This has fundamental ramifications for the quality of team decision-making and the effectiveness of new ways of inter-professional working in intensive care.     

Human osteoarthritic chondrons outnumber patient‐ and joint‐matched chondrocytes in hydrogel culture—Future application in autologous cell‐based OA cartilage repair?

Autologous chondrocyte implantation (ACI) is used in 34–60% for osteoarthritic (OA) cartilage defects, although ACI is neither recommended nor designed for OA. Envisioning a hydrogel‐based ACI for OA that uses chondrons instead of classically used chondrocytes, we hypothesized that human OA chondrons may outperform OA chondrocytes. We compared patient‐ and joint surface‐matched human OA chondrons with OA chondrocytes cultured for the first time in a hydrogel, using a self‐assembling peptide system. We determined yield, viability, cell numbers, mRNA expression, GAPDH mRNA enzyme activity, Collagen II synthesis (CPII) and degradation (C2C), and sulfated glycosaminoglycan. Ex vivo, mRNA expression was comparable. Over time, significant differences in survival led to 3.4‐fold higher OA chondron numbers in hydrogels after 2 weeks (p = .002). Significantly, more enzymatically active GAPDH protein indicated higher metabolic activity. The number of cultures that expressed mRNA for Collagen Types I and VI, COMP, aggrecan, VEGF, TGF‐β1, and FGF‐2 (but not Collagen Types II and X) was different, resulting in a 3.5‐fold higher number of expression‐positive OA chondron cultures (p < .05). Measuring CPII and C2C per hydrogel, OA chondron hydrogels synthesized more than they degraded Collagen Type II, the opposite was true for OA chondrocytes. Per cell, OA chondrons but not OA chondrocytes displayed more synthesis than degradation. Thus, OA chondrons displayed superior biosynthesis and mRNA expression of tissue engineering and phenotype‐relevant genes. Moreover, human OA chondrons displayed a significant survival advantage in hydrogel culture, whose presence, drastic extent, and timescale was novel and is clinically significant. Collectively, these data highlight the high potential of human OA chondrons for OA ACI, as they would outnumber and, thus, surpass OA chondrocytes.     

Clinicians’ response to hyperoxia in ventilated patients in a Dutch ICU depends on the level of FiO<Subscript>2</Subscript>

Purpose  

Hyperoxia may induce pulmonary injury and may increase oxidative stress. In this retrospective database study we aimed to evaluate the response to hyperoxia by intensivists in a Dutch academic intensive care unit.     

Comparison of [<Superscript>99m</Superscript>Tc]3PRGD<Subscript>2</Subscript> Imaging and [<Superscript>18</Superscript>F]FDG PET/CT in Breast Cancer and Expression of Integrin α<Subscript>v</Subscript>β<Subscript>3</Subscript> in Breast Cancer Vascular Endothelial Cells

Purpose

This study aimed to investigate the value of ^99mtechnetium-three polyethylene glycol spacers-arginine-glycine-aspartic acid ([^99mTc]3PRGD₂) imaging in diagnosis and staging of breast cancer compared with 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) imaging, and to explore the expression of integrin α_vβ₃ in tumor vascular endothelial cells.

Procedures

Forty-two women with suspected breast cancer underwent both [^99mTc]3PRGD₂ imaging and [¹⁸F]FDG imaging. Visual analysis was used to assess primary breast lesion, axillary lymph node, and distant metastasis. The tumor-blood (T/B) ratios from [^99mTc]3PRGD₂ imaging and the maximum standardized uptake value (SUVmax) from [¹⁸F]FDG imaging were analyzed for breast lesions. Integrin α_vβ₃ was analyzed through immunohistochemistry.

Results

Forty-five breast lesions were found (malignant, n?=?38; benign, n?=?7). The sensitivity, specificity, and accuracy of [^99mTc]3PRGD₂ and [¹⁸F]FDG imaging in visual analysis for the breast lesion were 97.4, 87.5, and 95.6 % and 97.4, 71.4, and 93.3 %, respectively (P?>?0.05). For semi-quantitative analysis, no significant difference of the area under the curves (AUC) was found in the imaging using the two radiopharmaceuticals (0.880 and 0.955; Z?=?0.88, P?>?0.05). The sensitivity, specificity, and accuracy for axillary lymph node metastasis with [^99mTc]3PRGD₂ and [¹⁸F]FDG were 78.05, 99.36, and 94.92 % and 85.37, 98.72, and 95.64 %, respectively (P?>?0.05). Nine patients with distant metastases were all detected with the two radiopharmaceuticals. The expression of integrin α_vβ₃ was correlated with [^99mTc]3PRGD₂ uptake (r?=?0.582, P?=?0.001), which were significantly higher in the HER2-positive and stage III–IV patients (P?<?0.05).

Conclusions

The prospective study demonstrated that [^99mTc]3PRGD₂ imaging seems to be valuable for diagnosis of breast cancer and its staging. It may be less sensitive for detecting small lymph node metastatic lesions when compared with [¹⁸F]FDG imaging. Integrin α_vβ₃ in tumor microvessels was associated with the breast cancer subtype and its staging.

     

Observations,confirmations and strategies – useful tools in decision‐making process for nurses in practice?

The aim of the study was to describe how nurses make decisions on measures in clinical practice. The data-collection method consisted of audio-taped interviews with six nurses. The interviews were then transcribed verbatim. The questions in the interviews were based on nursing situations observed earlier when the nurses initiated and implemented patient-related measures and the focus was on the nurses' experience of decision making. A content analysis was performed. The results show that the nurses' decisions on measures were based on three themes: observation of cues related to the patient's situation, confirmation of information gathered and implementation of action strategies. The results are discussed in relation to earlier empirical research on decision-making activities in the nurse's clinical practice and the nurse's utilization of knowledge during the decision-making process. It is concluded that the nurse's awareness of the patient's situation, together with a well-founded basis for decisions, can have positive effects on the nursing care provided by the nurse.     

Evaluation of the Microstat™ sublingual PCO<Subscript>2</Subscript> monitor in ambulatory patients

Physicians often need to measure arterial PCO₂ in clinical practice. Arterial blood gas sampling is typically available only in hospitals and may be unpleasant for patients. Minimally invasive techniques for measuring PCO₂ offer the potential for overcoming these limitations. The MicroStat monitor non-invasively measures PCO₂ in the sublingual tissues, which should track arterial PCO₂ in hemodynamically stable patients. This was a prospective observational study. Patients undergoing routine cardiac catheterization were recruited. Following arterial cannulation, two sequential sublingual PCO₂ measurements were taken and a contemporaneous arterial sample was sent for blood gas analysis. For each subject we calculated the mean sublingual–arterial CO₂ gradient and the test–retest sublingual PCO₂ difference. Twenty-five patients were studied. Mean sublingual–arterial PCO₂ gradient was +6.8 mmHg (95 % limits of agreement ?3.0 to 16.6 mmHg). Test–retest difference was 3.4 mmHg (95 % limits of agreement ?1.1 to 7.9 mmHg), p = 0.11 (Wilcoxon test), repeatability was 11 mmHg. The MicroStat sublingual PCO₂ monitor over-estimates arterial PCO₂ with wide limits of agreement. Test–retest repeatability was poor. Use of sublingual PCO2 monitoring with the MicroStat monitor cannot currently replace blood gas sampling.     

Specific Targeting of Human Integrin α<Subscript>v</Subscript>β<Subscript>3</Subscript> with <Superscript>111</Superscript>In-Labeled Abegrin™ in Nude Mouse Models

Purpose  

The cell adhesion molecule integrin α_vβ₃ is an important player in the process of tumor angiogenesis and metastasis. Abegrin™, a fully humanized anti-integrin α_vβ₃ monoclonal antibody, was currently in clinical trials for cancer therapy. Herein, we labeled Abegrin™ with ¹¹¹In, evaluated the in vitro and in vivo characteristics, and investigated whether the expression of integrin α_vβ₃ in tumors could be imaged with ¹¹¹In-labeled Abegrin™.     

Propriétés antioxydantes et antimicrobiennes des extraits de <Emphasis Type="Italic">Myrtus nivellei</Emphasis> Batt et Trab. obtenus <Emphasis Type="Italic">in situ</Emphasis> et <Emphasis Type="Italic">in vitro</Emphasis>

This work provides a contribution to the investigation and valorization of the Sahara-endemic plant: Myrtus nivellei Batt & Trab and the evaluation of the antioxidant effect of methanolic extracts harvested in situ, and in vitro propagated calli of this plant. Several spectrophotometric analyzes were performed, showing that the in situ methanolic extract was richer in polyphenols than the in vitro methanolic extract. Also, It expressed a good power to scavenge free radicals (EC50 = 0.98 mg/ml) and a great capacity to inhibit the peroxidation of linoleic acid estimated as 74.01%, largely higher than the ascorbic acid (50.57%) used as a positif control. However, the methanolic extracts of calli expressed the best ferric reducing power estimated as 66.71%. A very good antimicrobial activity was recorded for the extract of the plant harvested in situ, particularly against S. aureus (MIC=2.25 mg/ml), also against S. pneumoniae, S. flexineri, S. typhi and C. albicans (MIC=4.5 mg/ml). However, the calli extracts had presented no anti-microbial effect.     

Size does matter – Age-related weight estimation in “tall n’ thin” and “tiny n’ thick” children and a new habitus-adapted alternative to the EPLS-formula

Aim of the study

Weight in kilograms is a required parameter in the emergency medical care of children. In emergent situations, obtaining an accurate weight is often not possible. In such situations, weight can be estimated by using an age-dependent formula such as the EPLS-formula (age in years + 4) × 2. As recently recognized for emergency tapes, the habitus of the child has a major influence on weight estimation. In this study, the performance of various age-dependent formulas is to be investigated, with special regard to children demonstrating non-normal growth.

Methods

The performance of various formulas for weight estimation in children growing along the 5th, 50th, and 95th percentile is investigated based on a mathematical model compared to the WHO and CDC reference percentiles using ICC and Bland–Altman methods. Additionally, a new formula for children demonstrating non-normal growth is derived by regression analysis and tested: f × age in years + 6 with the factor f being 2 for “tall n’ thin”, 3 for normal and 4 for “tiny n’ thick” children.

Results

All previously published formulas lack precision when applied to children outside the 50th percentile. The new habitus-adapted formula shows a better performance for children growing along the 5th or 95th percentile.

Conclusions

The new formula provides enhanced precision in weight estimation and can help in reducing, e.g. drug dosing errors. It should be used for weight estimation in children demonstrating non-normal weight development and in situations when superior methods such as weighing or habitus-adapted emergency tapes are not applicable.