Guidelines for inhaled sedation in the ICU

INTRODUCTION AND OBJECTIVES

Sedation is used in intensive care units (ICU) to improve comfort and tolerance during mechanical ventilation, invasive interventions, and nursing care. In recent years, the use of inhalation anaesthetics for this purpose has increased. Our objective was to obtain and summarise the best evidence on inhaled sedation in adult patients in the ICU, and use this to help physicians choose the most appropriate approach in terms of the impact of sedation on clinical outcomes and the risk-benefit of the chosen strategy.

METHODOLOGY

Given the overall lack of literature and scientific evidence on various aspects of inhaled sedation in the ICU, we decided to use a Delphi method to achieve consensus among a group of 17 expert panellists. The processes was conducted over a 12-month period between 2022 and 2023, and followed the recommendations of the CREDES guidelines.

RESULTS

The results of the Delphi survey form the basis of these 39 recommendations - 23 with a strong consensus and 15 with a weak consensus.

CONCLUSION

The use of inhaled sedation in the ICU is a reliable and appropriate option in a wide variety of clinical scenarios. However, there are numerous aspects of the technique that require further study.

Cytotoxicity in Vero cells and cytokines analyses in Balb/c mice as safety assessments of the probiotic mixture Saccharomyces cerevisiae RC016 and Lactobacillus rhamnosus RC007 for use as a feed additive

The objective was to carry out cytotoxicity assays in Vero cells and cytokines analyses in Balb/c mice as safety assessments to evaluate the probiotic mixture (M) Saccharomyces cerevisiae RC016 (Sc) and Lactobacillus rhamnosus RC007 (Lr) for use as feed additive. Vero cells (10⁴ cells per well) were exposed to Sc (2·08 × 10⁷ , 2·08 × 10⁶ ; 2·08 × 10⁵ cells per ml), Lr (8·33 × 10⁷ ; 8·33 × 10⁶ ; 8·33 × 10⁵ cells per ml) and their M (1 : 1). Sc concentrations did not affect the Vero cells viability; in contrast, they were lower when exposed to Lr (P ˂ 0·0001). Vero cells showed increasing viability with M decreasing concentrations (91% viability with M2). Control BALB/c mice received only phosphate buffer saline and the others received the M. The IL-10, IL-6 and TNFα concentrations from intestinal fluid were analysed and no significant differences were observed among treatments. The same occurred with the ratio between IL-10/TNF-α. Beneficial effects of probiotics are associated with the regulation of the excessive inflammatory response; it is desirable they can modulate the cytokines production only under pathological conditions. Here, M administration to healthy mice did not induce negative side effects and expands the knowledge about beneficial effects of using probiotic microorganisms in mixture for feed additives development.

Presence of aiiA homologue genes encoding for N-Acyl homoserine lactone-degrading enzyme in aflatoxin B1-decontaminating Bacillus strains with potential use as feed additives

Microbial degradation of aflatoxins (AFs) is an alternative to the use of mycotoxin binders. The lactone ring is a possible target for microbial enzymes and its cleavage reduces AFs toxicity. The aim of this study was to isolate and identify Bacillus strains able to degrade AFB₁ to less toxic metabolites and to identify aiiA genes encoding for N-acyl-homoserine lactone (AHL) lactonase to possibly correlate detoxification with the production of this enzyme. Eleven soilborne Bacillus strains were isolated and identified by MALDI-TOF MS. Ten cultures and eight cell free culture supernatants (CFCS) were able to significantly (P < 0.05) degrade 27.78-79.78% AFB₁. Cell lysates were also able to degrade AFB₁ (P < 0.05). Exposure to 70 and 80 °C did not affect enzyme activity. Aflatoxin B₁ toxicity towards Artemia salina was reduced after degradation by each of the Bacillus strains. B. subtilis RC1B, B. cereus RC1C and B. mojavensis RC3B, amplified a fragment of 753 pb corresponding to the aiiA gene encoding for AHL lactonase. AFB₁ degradation by the strains tested was due to the extracellular and intracellular enzymes. If demonstrated to be safe, these could be used to detoxify AFB₁ in contaminated food or feed.

The effect of five Taraxacum species on in vitro and in vivo antioxidant and antiproliferative activity

Differences between antioxidant and cytotoxic activities have been found among five Taraxacum species.

Endocrine manifestations of Langerhans cell histiocytosis diagnosed in adults

Langerhans cell histiocytosis (LCH) is a rare granulomatous disease of unknown etiology. We retrospectively reviewed data from four patients (3 males and 1 female), mean age 33.5 years old (range: 21-40), with histopathological diagnosis of LCH. All of them presented with symptoms suggestive of endocrine involvement. The main complaint was goiter in two patients and polyuria and polydipsia in three. Before the LCH diagnosis, two patients had unevaluated symptoms of diabetes insipidus (DI) and hypogonadism. The mean time from symptoms onset to diagnosis was 6.25 years (range: 2-13). Histopathological diagnosis was established by total thyroidectomy (TT) biopsy in two patients, skin lesion biopsy in one, and pituitary stalk biopsy in the other. In the two-first patients, surgery was indicated after the fine-needle aspiration biopsy (FNAB) showed a false positive result of differentiated thyroid carcinoma and immunohistochemistry was used for diagnosis confirmation. Three cases were treated with chemotherapy; one of them had already received radiation therapy on the hypothalamic-pituitary region, developing post-radiation hypopituitarism.

Determination of phthalates in wine by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry. Use of deuterated phthalates as internal standards

This study proposes the use of deuterated phthalates as internal standards for the accurate determination of phthalates in wine by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry. Unlike other internal standards proposed previously such as benzyl benzoate, deuterated phthalates enabled matrix-error free determinations to be performed without standard addition because statistically equal slopes were obtained for synthetic, white, rose and red wines. The relative standard deviation values under intermediate precision conditions ranged from 0.24 to 4.6%, and detection limits below 35 ng L(-1) were obtained. Recovery values were around 100% in most of cases and the method provided similar results to standard addition. Finally, the method was used to screen phthalate levels in 10 wine samples.

Irinotecan plus raltitrexed as first-line treatment in advanced colorectal cancer: a phase II study

To evaluate the efficacy and toxicity of irinotecan (CPT-11) in combination with raltitrexed as first-line treatment of advanced colorectal cancer (CRC). A total of 91 previously untreated patients with advanced CRC and measurable disease were enrolled in this phase II study. The median age was 62 years (range 31–77); male/female 54/37; ECOG performance status was 0 in 50 patients (55%), one in 39 (43%) and two in two (2%). Treatment consisted of CPT-11 350 mg m⁻² in a 30-min intravenous infusion on day 1, followed after 30 min by a 15-min infusion of raltitrexed 3 mg m⁻². Measurements of efficacy included the following: response rate, time to disease progression and overall survival. Of the 83 evaluable patients valuable to objective response, there were five complete responses (6%) and 23 partial responses (28%), for an overall response rate of 34% (95% CI: 25.9–46.5%). In all, 36 patients (43%) had stable disease, whereas 19 (23%) had a progression. The median time to progression was 11.1 months and the median overall survival was 15.6 months. A total of 487 cycles of chemotherapy were delivered with a median of five per patient. Grade 3–4 WHO toxicities were as follows: diarrhoea in 13 patients (15%), nausea/vomiting in four (4%), transaminase increase in six (7%), stomatitis in two (2%), febrile neutropenia in three (3%), anaemia in five (6%) and asthenia in three (3%). The combination CPT-11–raltitrexed is an effective, well-tolerated and convenient regimen as front-line treatment of advanced CRC.

Immunohistochemical and functional evidence for a noradrenergic regulation in the horse penile deep dorsal vein

Our aim was to study the presence of noradrenergic nerves and to characterize the alpha-adrenergic receptors involved in the contractions to electrical field stimulation and to alpha-adrenergic agonists of the horse penile deep dorsal vein. Noradrenergic fibres were visualized by immunohistochemistry using an antibody against dopamine-beta-hydroxylase (DBH). For functional studies, the responses of the venous rings to electrical field stimulation and to alpha-adrenergic agonists (noradrenaline, phenylephrine and BHT 920) were studied in the absence and the presence of noradrenergic transmission- and neuronal sodium channel-blockers (guanethidine and tetrodotoxin, respectively) and of alpha1- and alpha2-adrenergic antagonists (prazosin and rauwolscine, respectively). DBH-immunoreactive fibres were present in the adventitia and in the media layer of the venous rings. Electrical field stimulation (0.5-32 Hz) caused frequency-dependent contractions that were abolished by guanethidine (10(-6) M) and tetrodotoxin (10(-6) M) and reduced by prazosin (10(-9)-10(-7) M) and rauwolscine (3 x 10(-8)-3 x 10(-7) M). Noradrenaline, phenylephrine and BHT 920 induced equipotent contractions of the rings. Prazosin and rauwolscine competitively antagonized the contractions to phenylephrine and BHT 920, respectively. In conclusion, DBH-immunoreactive nerve fibres are present in the horse penile dorsal vein. Both transmural nerve stimulation and alpha-adrenergic agonists induce contraction of the venous rings through a heterogeneous population of alpha1- and alpha2-adrenoceptors.

Erythropoietin assay in mice made polycythemic by transfusion of heterologous red cells

A simple in vivo bioassay suitable for routine testing of quality control of recombinant human erythropoietin (rHu-EPO) analogues was developed. Mice made polycythemic by intraperitoneal injection of 1.2 ml of a 80% suspension of heterologous (rat) red cells were used as assay animals and splenic 59Fe uptake as expression of the response to rHu-EPO. The assay took three days and the following schedule is proposed: 1) intraperitoneal injection of 1.2 ml of washed packed red cells obtained from donor rats, 2) subcutaneous injection of test material 4-5 h after transfusion, 3) intravenous administration of 59Fe tracer 48 h later, and 4) determination of splenic isotope uptake 6 h after injection. This method for the in vivo bioassay of rHu-EPO analogues is an economical and reliable alternative to the existing bioassays of the hormone.

Longitudinal assessment of L-T4 therapy for congenital hypothyroidism: differences between athyreosis vs ectopia and delayed vs normal bone age

To study the effects of LT4 dose on thyroid hormone serum levels, a prospective, longitudinal and comparative study was designed, including 56 term eutrophic 1-89 day-old infants with congenital hypothyroidism (CH) detected by neonatal screening. Patients were divided into four groups according to delayed or normal bone age at birth, and athyreosis or ectopic thyroid. All received an initial dose of 50 micrograms/day (12.9-13.7 micrograms/kg/day) LT4 and were followed bimonthly (first year) and quarterly (second year) with thyroid profile and bone age determinations at 6, 12 and 24 months. At diagnosis, hormone levels were higher in cases of ectopia than in athyreosis (p < 0.001), and T4 was lower in children with delayed than in normal bone age at birth (p < 0.05). During treatment, all groups were clinically euthyroid despite T4 and FT4 serum levels higher than the upper normal limit (p < 0.0.001), though T3 and FT3 were within the normal limit (p > 0.05). TSH normalized within 8 weeks. Bone age accelerated at 2 years in eight children of the bone age delayed group. No patient had craniosynostosis.

Plasma disappearance of exogenous erythropoietin in mice under different experimental conditions

Erythropoietin (EPO) is a glycoprotein hormone produced primarily in the kidneys and to a lesser extent in the liver that regulates red cell production. Most of the studies conducted in experimental animals to assess the role of EPO in the regulation of erythropoiesis were performed in mouse models. However, little is known about the in vivo metabolism of the hormone in this species. The present study was thus undertaken to measure the plasma tl/2 of radiolabeled recombinant human EPO (rh-EPO) in normal mice as well as in mice with altered erythrocyte production rates (EPR), plasma EPO (pEPO) titer, marrow responsiveness, red cell volume, or liver function. Adult CF-1 mice of both sexes were used throughout. For the EPO life-span studies, 30 mice in each experiment were intravenously injected with 600,000 cpm of 125l-rh-EPO and bled by cardiac puncture in groups of five every hour for 6 h. Trichloroacetic acid (TCA) was added to each plasma sample and the radioactivity in the precipitate measured in a gamma-counter. EPO, pEPO, marrow responsiveness, or red cell volume were altered by either injections of rh-EPO, 5-fluorouracil, or phenylhydrazine, or by bleeding, or red cell transfusion. Liver function was altered by CI4C administration. In the normal groups of mice, the estimated tl/2 was 182.75+/-14.4 (SEM) min. The estimated tl/2 of the other experimental groups was not significantly different from normal. These results, therefore, strongly suggest that the clearance rate of EPO in mice is not subjected to physiologic regulation and that pEPO titer can be really taken as the reflection of the EPO production rate, at least in the experimental conditions reported here.

Organochlorine pesticides in pasteurized milk and associated health risks

The presence of organochlorine pesticides (alpha-HCH, beta-HCH, lindane, aldrin, dieldrin, heptachlor, heptachlor epoxide, chlordane and the isomers and metabolites of DDT) in Spanish pasteurized milk were investigated. 95% of the samples contained one of the isomers of the HCH group and 12.9% of them exceeded the maximum residue limit permitted by the European Union; six samples went over that limit for heptachlor epoxide and 74.63% of the samples contained chlordane at higher concentrations than those permitted by the legislation. None of the samples exceeded the limit for the DDT group. The mean concentrations detected for each pesticide were as follows (mg/kg): alpha-HCH = 0.015; beta-HCH = 0.039; lindane = 0.007; delta-HCH = 0.07; aldrin = 0.002; dieldrin = 0.028; chlordane = 0.101; heptachlor = 0.011; heptachlor epoxide = 0.021; o.p'-DDD = 0.016; p.p'-DDD = 0.009; p.p'-DDE = 0.045 (DDT + metabolites = 0.067).

Unexpected hypoxia-dependent erythropoietin secretion during experimental conditions not affecting tissue oxygen supply/demand ratio

Although a great deal of evidence supports the hypothesis that plasma erythropoietin (EPO) levels of mammals are related to the oxygen supply to the tissues relative to their oxygen needs, several observation millitate against its inherent simplicity. This study presents our results obtained from in vivo experiments that suggest that hypoxia-dependent EPO production can be altered by conditions which apparently do not modify the tissue oxygen supply/demand ratio. Hypoxia-dependent EPO production rate (EPO-PR), derived from plasma EPO titers and plasma EPO half-lives, were estimated in both transfused-polycythemic and normocythemic mouse models subjected to different treatments. From calculations of the O2 carrying capacity of blood and body O2 consumption, it was assumed that the tissue supply/demand ratios were similar in both experimental and control mice of the same model at the time of induction of EPO production. The following observations were worth noting: (1) EPO-PRs in transfused polycythemic mice whose erythropoietic rates were stimulated by intermittent exposure to hypobaria (0.5 atm, 18 hr/day x 3 weeks), phenylhydrazine administration (40 mg/kg at weekly intervals x 3 weeks) or repeated rh-EPO injections (1500 U/kg 3 times a week x 3 weeks) before transfusion were more than five times high than in comparabily polycythemic mice whose erythropoietic rates were not stimulated previously; and (2) EPO-PR in response to hypobaric hypoxia was 2.08 times normal in normocythemic mice with cyclophosphamide (100 mg/kg) induced depression of erythropoiesis, and 0.33 times normal in normocythemic mice with rh-EPO (400 U/kg x 2) induced enhancement of erythropoiesis. Although the results obtained in polycythemic mice are difficult to explain, those from normocythemic mice suggest the existence of a feedback mechanism between EPO-responsive cells and EPO-producing cells. Both demonstrate the existence of experimental conditions in which modulation of the hypoxia-dependent expression of the EPO gene appears to occur. This modulation would be dependent on factors other than oxygen.

Depression of stimulated erythropoietin production in mice with enhanced erythropoiesis

BACKGROUND

The reports of lower plasma erythropoietin (EPO) in anemic patients with active erythropoiesis (hyperplastic) than in comparably anemic subjects with erythroid hypoplasia have generally been interpreted as the result of EPO utilization by the target cells of the hormone. An alternative explanation could be that there is a feedback mechanism through which EPO formation by EPO-producing cells is modulated by the erythroid activity of the erythropoietic organs. The present study was thus designed to investigate EPO production during acute hypoxemia in a mouse model in which the oxygen-carrying capacity of blood, the plasma EPO level, the blood viscosity and the plasma EPO half-life are within normal values in spite of an intense stimulation of erythropoiesis.

MATERIALS AND METHODS

Adult female mice of the CF1 strain with either normal or increased rates of erythropoiesis were used in this study. Erythropoiesis was stimulated by two injections of 10 units of rhEPO given 24 h apart. All experimental determinations were performed 24 h after the second EPO injection. Erythropoiesis was measured by the percent of a tracer dose of 59Fe incorporated into the spleen. Hypobaric hypoxemia was induced by exposing mice to atmospheric air maintained at 50% atmospheric pressure for 6 h. Plasma EPO concentration was determined by RIA. Plasma disappearance of radiolabeled rhEPO was determined by i.v. injection of the hormone and sampling by cardiac puncture every hour for 6 h.

RESULTS

Administration of rhEPO to mice increased splenic 59Fe uptake significantly without affecting the hematocrit, the plasma EPO level or the plasma disappearance of radiolabeled EPO. Plasma EPO titer after 6 h of exposure to hypobaric air was about 70% lower in mice with EPO-induced stimulation of erythropoiesis than in mice with normal erythropoiesis.

CONCLUSIONS

The results of this study suggest that there is an inverse relationship between the rate of stimulated EPO production and erythropoietic marrow activity. They also suggest that the variations in plasma EPO levels during periods of rapidly increasing erythropoiesis are the reflection of a decrease in the rate of production rather than an increase in the rate of utilization by a proliferating pool of erythroid cells.

[Lucid alternating epileptic psychosis. Identification of neuropsychological deficit using the Luria-Nebraska neuropsychological battery]

The Luria-Nebraska neuropsychological battery (LNNB) was applied to 15 epileptic patients with clear consciousness episodic alternating psychoses. 73% of patients showed psycho-organic impairment. Epileptic patients with combinations of focal and generalized seizures had greater mental impairment (87%) compared to those who presented only focal seizures. Rythm, memory and intellectual processes were affected most. The right parieto-occipital and left frontal zones were the areas showing greater involvement. These results show a close relationship between neuropsychological impairment and the presence of clear consciousness episodic alternating epileptic psychoses.

[Absence of tuberculin reactivity after neonatal vaccination with BCG in Cantabria: analysis of 419 determinations]

A prospective study is made of the tuberculin test sensitivity at 3 and 12 months after neonatal vaccination with BCG. From the results obtained in 419 tests the conclusion is that the percentage of positive tests is 3.8% and 1.6% at 3 and 12 months respectively, considering the threshold of positivity equal or superior to 10 mm (or 18.9 y 5.6% respectively with the threshold at 5 mm). These results are lower than the ones described previously, and therefore the conclusion is that in Cantabria the tuberculin tests should be valued without taken in consideration the antecedent of previous vaccination with BCG.