Factors associated with treatment limitations in two Swedish intensive care units: Prevalence and patient involvement.

The aim was to study the prevalence, documentation, and patient involvement in treatment limitations (TLs) in two Swedish intensive care units (ICUs). All patients admitted to the ICUs of two Swedish regional hospitals in 2019 were screened for inclusion. Exclusion criteria included postanesthesia care <24 h. Patients were identified using the Swedish Intensive Care Registry (SIR) and data were extracted from SIR and hospital charts. Uni- and multivariable logistic analysis was performed to investigate associations with the presence of TLs. A total of 3090 patients were admitted to the two ICUs in 2019. After exclusion, 1019 patients were included in the study. 45.5% were women and the mean age was 62.9 years. 26.5% of the patients had one or several TLs. Age (OR 1.04 per one year increase 95% confidence interval (CI) 1.02-1.05), SAPS3-score (OR 1.08 per one unit increase 95% CI 1.06-1.09) and ICU length of stay (OR 1.11 per one day increase 95% CI 1.05-1.17) were independently associated with an increased likelihood of receiving a TL. 17% of the patients were involved in the decision-making process and in >30% of cases neither the patient nor next-of-kin were informed. Women were to a larger extent involved in the decision process than men (24.5 vs. 12.5% p < .05). When the intensivist documented why a TL was established, patient autonomy was four times more commonly stated as the motivation for the TL among women compared to men (15.5% vs. 3.8% p < .05). TLs were common in two Swedish ICUs but a substantial number of patients and next-of-kin were not involved in the decision-making process or informed of the decision. Women were more often than men engaged in the decision to establish a TL.

Plasma and bronchoalveolar lavage fluid oxylipin levels in experimental porcine lung injury.

Inflammatory signaling pathways involving eicosanoids and other regulatory lipid mediators are a subject of intensive study, and a role for these in acute lung injury is not yet well understood. We hypothesized that oxylipin release from lung injury could be detected in bronchoalveolar lavage fluid and in plasma. In a porcine model of surfactant depletion, ventilation with hyperinflation was assessed. Bronchoalveolar lavage and plasma samples were analyzed for 37 different fatty acid metabolites (oxylipins). Over time, hyperinflation altered concentrations of 4 oxylipins in plasma (TXB2, PGE2, 15-HETE and 11-HETE), and 9 oxylipins in bronchoalveolar lavage fluid (PGF2α, PGE2, PGD2, 12,13-DiHOME, 11,12-DiHETrE, 13-HODE, 9-HODE, 15-HETE, 11-HETE). Acute lung injury caused by high tidal volume ventilation in this porcine model was associated with rapid changes in some elements of the oxylipin profile, detectable in lavage fluid, and plasma. These oxylipins may be relevant in the pathogenesis of acute lung injury by hyperinflation.

Touch massage: a pilot study of a complex intervention.

OBJECTIVES: To report and evaluate a complex touch massage intervention according to the British Medical Research Council framework. This study aimed to evaluate the effects of touch massage on levels of anxiety and physiological stress in patients scheduled for elective aortic surgery. BACKGROUND: The use of touch massage has increased during the past decade but no systematic studies have been implemented to investigate the effectiveness of such treatment. It is important to conduct multidisciplinary investigations into the effects of complex interventions such as touch massage. For this, the British Medical Research Council has provided a useful framework to guide the development, piloting, evaluation and reporting of complex intervention studies. METHOD: A pilot study with a randomized controlled design including 20 patients (10 + 10) scheduled for elective aortic surgery. Selected outcome parameters included; self-reported anxiety, measured by the State-Trait Anxiety Inventory Form Y instrument, and physiological stress, measured by heart rate variability, blood pressure, respiratory frequency, oxygen saturation and concentrations of cortisol, insulin and glucose in serum. RESULTS: There were significant differences in self-reported anxiety levels before and after touch massage (p = 0.007), this was not observed in the control group (p = 0.833). There was a significant difference in self-reported anxiety levels between the touch massage group and the control group after touch massage and rest (p = 0.001). There were no significant differences in physiological stress-related outcome parameters between patients who received touch massage and controls. CONCLUSION: In our study, touch massage decreased anxiety levels in patients scheduled for elective aortic surgery, and the British Medical Research Council framework was a useful guideline for the development, evaluation and reporting of a touch massage intervention. RELEVANCE TO CLINICAL PRACTICE: Touch massage can reduce patients' anxiety levels and is thus an important nursing intervention in intensive and post-operative care.

Pleasant human touch is represented in pregenual anterior cingulate cortex.

Touch massage (TM) is a form of pleasant touch stimulation used as treatment in clinical settings and found to improve well-being and decrease anxiety, stress, and pain. Emotional responses reported during and after TM have been studied, but the underlying mechanisms are still largely unexplored. In this study, we used functional magnetic resonance (fMRI) to test the hypothesis that the combination of human touch (i.e. skin-to-skin contact) with movement is eliciting a specific response in brain areas coding for pleasant sensations. The design included four different touch conditions; human touch with or without movement and rubber glove with or without movement. Force (2.5 N) and velocity (1.5 cm/s) were held constant across conditions. The pleasantness of the four different touch stimulations was rated on a visual analog scale (VAS-scale) and human touch was rated as most pleasant, particularly in combination with movement. The fMRI results revealed that TM stimulation most strongly activated the pregenual anterior cingulate cortex (pgACC). These results are consistent with findings showing pgACC activation during various rewarding pleasant stimulations. This area is also known to be activated by both opioid analgesia and placebo. Together with these prior results, our finding furthers the understanding of the basis for positive TM treatment effects.

Evaluation of intestinal preconditioning in a porcine model using classic ischemic preconditioning or lung recruitment maneuvers.

To test the hypotheses that repeated brief intestinal ischemic insults would elicit an intestinal preconditioning response to a subsequent intestinal I/R injury and that a similar response would be elicited by repeated lung recruitment maneuvers (RMs). Randomized experimental controlled animal study. University hospital animal laboratory. Eighteen anesthetized pigs. Animals were randomized to one of three groups, with six animals in each group. Control group 75-min superior mesenteric artery (SMA) occlusion followed by 60-min reperfusion. Ischemic preconditioning group, three 5-min-long SMA occlusions preceding 75-min SMA occlusion and 60-min reperfusion. Recruitment maneuver (RM) group, three 2-min-long RMs preceding 75-min SMA occlusion and 60-min reperfusion. We measured systemic and mesenteric hemodynamic parameters, jejunal mucosal perfusion, net mesenteric lactate flux, jejunal tissue oxygen tension, and mesenteric oxygenation. Every 15 min, jejunal microdialysate samples were collected and analyzed for glucose, lactate, and glycerol. Jejunal tissue samples were collected postmortem. After occlusion of SMA, regional parameters in all groups indicated abolished perfusion and gradually increasing intraluminal microdialysate lactate and glycerol levels. At reperfusion, regional parameters indicated mesenteric hyperperfusion, whereas microdialysis markers of mucosal anaerobic metabolism and cell injury decreased, although not reaching baseline. Histological examination revealed severe mucosal injury in all groups. There were no significant differences between groups in the observed parameters. No protective preconditioning response could be observed when performing repeated brief intestinal ischemic insults or repeated lung RMs before an intestinal I/R injury.

Negative mesenteric effects of lung recruitment maneuvers in oleic acid lung injury are transient and short lasting.

OBJECTIVE: To test the hypothesis that repeated recruitment maneuvers (RMs) have sustained negative effects on mesenteric circulation, metabolism, and oxygenation 60 mins after RMs in pigs with oleic acid lung injury. Further, we aimed to test the hypothesis that an infusion of prostacyclin (PC) at 33 ng.kg.min would attenuate such possible negative mesenteric effects. DESIGN: Randomized, experimental, controlled study. SETTING: University hospital animal laboratory. SUBJECTS: A total of 31 anesthetized, fluid-resuscitated pigs with oleic acid lung injury. INTERVENTIONS: : Animals were randomized to one of the following four groups: a control group (n = 7) that received no intervention, recruitment group (n = 8) that underwent the RM sequence, a prostacyclin group (n = 8) that received an infusion of PC, and a recruitment-prostacyclin group (n = 8) that received an infusion of PC and concomitant RM sequence. MEASUREMENTS AND MAIN RESULTS: We measured systemic and mesenteric hemodynamic variables, jejunal mucosal perfusion, mesenteric lactate flux, jejunal tissue oxygen tension, and mesenteric oxygen delivery, uptake, and extraction ratio. Five minutes after RMs, mesenteric oxygen extraction ratio and mesenteric lactate flux were more prominently increased in the recruitment group, giving evidence of worsened mesenteric conditions after RMs. These signs of worsened conditions were further supported by more decreased jejunal tissue oxygen tension and portal vein oxygen saturation in the recruitment group. PC preserved mesenteric oxygenation, as indicated by less of a decrease in portal vein oxygen saturation at the time corresponding to 5 mins after RM and less of a decrease in mesenteric oxygen delivery at the time corresponding to 15 mins after RM. PC preserved mesenteric oxygenation as indicated by less of a decrease in portal vein oxygen saturation at 5 mins after RM and an attenuated increase in mesenteric oxygen extraction ratio at 5 mins after RM. There was a trend toward worsened jejunal mucosal perfusion, although not significant. CONCLUSIONS: In an oleic acid lung injury model, three repeated RMs did not improve systemic oxygenation or lung mechanics. Negative effects on mesenteric oxygenation and metabolism were transient and short lasting. The intestinal effects of PC during RMs were minor and opposing, showing preserved oxygenation but a trend toward worsened mucosal perfusion.

Intestinal circulation, oxygenation and metabolism is not affected by oleic acid lung injury.

This study was performed to establish a platform for further studies on effects of ventilatory treatment modalities on the intestines during mechanical ventilation of acute lung injury (ALI). We tested the hypotheses that oleic acid (OA) infusion causes changes in intestinal circulation, oxygenation and metabolism, and that OA is distributed to tissues outside the lung. This was performed as an experimental, prospective and controlled study in an university animal research laboratory. Thirteen juvenile anaesthetized pigs were used in the main study, where seven were given an intravenous infusion of 0.1 ml kg(-1) OA and six served as control (surgery only). In a separate study, four animals were given an intravenous infusion of 0.1 ml kg(-1) (3)H-labelled OA. We measured systemic and mesenteric (portal venous blood flow, jejunal mucosal perfusion) haemodynamic parameters, mesenteric oxygenation (jejunal tissue oxygen tension) and systemic cytokines (tumour necrosis factor-alpha and interleukin-6). We calculated mesenteric lactate flux and mesenteric oxygen delivery, uptake and extraction ratio. In the animals given 3H-OA, we measured 3H-OA in different tissues (lungs, heart, liver, kidney, stomach, jejunum, colon and arterial blood). We found that OA given intravenously is distributed in small amounts to the intestines. This intestinal exposure to OA does not cause intestinal injury when evaluating mesenteric blood flow, metabolism or oxygenation. OA infusion induced a moderate increase in mean pulmonary arterial pressure and a decrease in PaO2/Fraction inspired O2 (P/F) ratio, giving evidence of severe lung injury. Consequently, the OA lung injury model is suitable for studies on intestinal effects of ventilatory treatment modalities during mechanical ventilation of ALI.

Local metabolic effects of dopexamine on the intestine during mesenteric hypoperfusion.

This self-controlled experimental study was designed to test the hypothesis that dopexamine, a synthetic catecholamine that activates dopaminergic (DA-1) and beta2-adrenergic receptors, improves oxygenation in the jejunal mucosa during intestinal hypotension. In six normoventilated barbiturate-anesthetized pigs, controlled reductions in superior mesenteric arterial pressure (PSMA) was obtained by an adjustable clamp around the artery. Dopexamine infusions (0.5 and 1.0 microg.kg(-1).min(-1)) were administered at a freely variable PSMA (i.e., with the perivascular clamp fully open) and at a PSMA of 50 mmHg and 30 mmHg. We continuously measured superior mesenteric venous blood flow (QMES; transit-time ultrasonic flowmetry), jejunal mucosal perfusion (laser Doppler flowmetry), and tissue oxygen tension (PO2TISSUE; microoximetry). Jejunal luminal microdialysate of lactate, pyruvate, and glucose were measured every 5 min. Measurements of mucosal PCO2 (air tonometry), together with blood sampling and end-tidal PCO2 measurements, enabled calculations of pHi and PCO2 gap. Dopexamine reduced mesenteric vascular resistance and increased QMES at a PSMA of 50 mmHg and 30 mmHg. At a PSMA of 30 mmHg, dopexamine increased mesenteric oxygen delivery but did not influence mesenteric oxygen uptake or extraction. In this situation, dopexamine had no beneficial effect on jejunal mucosal blood flow. On the contrary, dopexamine increased mesenteric net lactate production and PCO2 gap, whereas PO2TISSUE and pHi decreased. Jejunal luminal microdialysate data demonstrated an increased lactate concentration and a pattern of decreased glucose concentration and increased luminal lactate-pyruvate ratio. These negative metabolic effects of dopexamine should be taken into account in situations of low perfusion pressures.

Effects of dopexamine and positive end-expiratory pressure on intestinal blood flow and oxygenation: the perfusion pressure perspective.

OBJECTIVE: To evaluate the net effects of the concomitant use of positive end-expiratory pressure (PEEP) and dopexamine on intestinal tissue perfusion and oxygenation during predefined artificial reductions in intestinal perfusion pressure (IPP). DESIGN: Prospective, self-controlled, experimental study. SETTING: University hospital research laboratory. SUBJECTS: Seven female pigs. MEASUREMENTS: In barbiturate-anesthetized pigs, we measured mesenteric blood flow (QMES) [by transit-time ultrasonic flowmetry], jejunal mucosal perfusion (by laser Doppler flowmetry), and tissue PO(2) (by microoximetry). Based on blood sampling, we calculated the intestinal net lactate production and oxygenation. INTERVENTIONS: These measurements and calculations were performed at three predefined and controlled IPP levels, which were obtained by an adjustable clamp around the superior mesenteric artery. At each IPP level, measurements were performed prior to and during PEEP (10 cm H(2)O), both with and without simultaneous dopexamine infusions (at 0.5 and 1.0 microg/kg/min). RESULTS: Within the IPP range of 77 to 33 mm Hg, intestinal perfusion and oxygenation were maintained irrespective of whether PEEP and/or dopexamine were applied or not. At IPP < 33 mm Hg, QMES and intestinal oxygenation deteriorated, resulting in regional net lactate production. At this IPP range, tissue oxygen perfusion was entirely pressure-dependent, and even small reductions in IPP led to prominent increases in intestinal net lactate production. Dopexamine did not modify this pattern. CONCLUSIONS: We describe maintained intestinal tissue oxygen perfusion within a wide perfusion pressure range. Within this perfusion pressure range, PEEP did not induce any adverse regional circulatory effects. Below the perfusion pressure range for effective autoregulation, intestinal tissue oxygen perfusion deteriorated, and regional ischemia occurred. In this situation, dopexamine was unable to counteract IPP-dependent decreases in intestinal tissue oxygen perfusion. The regional ischemic threshold can be defined either as an IPP of < 33 mm Hg or as an intestinal tissue PO(2) of < 45 mm Hg.