Phrenic nerve block on severe post-hepatectomy shoulder pain: A randomized, double-blind, placebo-controlled, pilot study.

BACKGROUND: Severe shoulder pain occurs frequently after surgery close to the diaphragm, potentially caused by referred pain via the ipsilateral phrenic nerve. We aimed to assess the analgesic effect of an ultrasound-guided phrenic nerve block on moderate to severe right-sided shoulder pain after open partial hepatectomy. METHODS: This was a randomized, double-blind, placebo-controlled, pilot study, comparing ultrasound-guided phrenic nerve block (ropivacaine 0.75 mg/mL) versus placebo (isotonic sodium chloride 0.9 mg/mL) on severe post-hepatectomy shoulder pain (NRS ≥6). Pre- and postoperative spirometry and arterial blood gas analyses were used to assess respiratory function. Subjects with chronic lung disease were excluded. Unfortunately, due to lack of funding, the trial was ended prematurely and therefore presented as a pilot study. RESULTS: One hundred and one subjects were screened for eligibility; 14 subjects were randomized, and two subjects were later excluded; thus, 12 subjects were analyzed with six in each group. A statistically significant difference in reduction in median pain intensity between groups was observed 15 minutes after phrenic nerve block ("ropivacaine first" ΔNRS: -6.0 [-6.0 to -3.0] vs. "saline first" ΔNRS: 0 [-6.0 to 1.0], P = .026). Spirometry results and arterial blood gas analyses were not clinically impacted by the block. CONCLUSIONS: Postoperative phrenic nerve block significantly reduced severe post-hepatectomy shoulder pain. Larger studies are warranted to confirm the lack of clinically relevant block-related impairment of respiratory function.

Substrate curvature governs texture orientation in thin films of smectic block copolymers.

Self-assembly of ordered nanometer-scale patterns is interesting in itself, but its practical value depends on the ability to predict and control pattern formation. In this paper we demonstrate theoretically and numerically that engineering of extrinsic as well as intrinsic substrate geometry may provide such a controllable ordering mechanism for block copolymers films. We develop an effective two-dimensional model of thin films of striped-phase diblock copolymers on general curved substrates. The model is obtained as an expansion in the film thickness and thus takes the third dimension into account, which crucially allows us to predict the preferred orientations even in the absence of intrinsic curvature. We determine the minimum-energy textures on several curved surfaces and arrive at a general principle for using substrate curvature as an ordering field, namely that the stripes will tend to align along directions of maximal curvature.

Friction-limited cell motility in confluent monolayer tissue.

Mechanical forces are important factors in the development, coordination and collective motion of cells. Based on a continuum-scale model, we consider the influence of substrate friction on cell motility in confluent living tissue. We test our model on the experimental data of endothelial and cancer cells. In contrast to the commonly used drag friction, we find that solid friction best captures the cell speed distribution. From our model, we quantify a number of measurable physical tissue parameters, such as the ratio between the viscosity and substrate friction.

A study of the reliability and construct validity of the 1-minute sit-to-stand test for individuals with systemic sclerosis.

OBJECTIVE: This study seeks to assess the reliability and construct validity of the 1-minute sit-to-stand test as an efficient tool for evaluating the functional capacity of individuals with systemic sclerosis, considering its time and space effectiveness. METHODS: This cross-sectional study recruited forty-nine individuals with systemic sclerosis from a university hospital in Denmark. The 1-minute sit-to-stand test was conducted twice on the same day, with an interval of approximately 10 to 15 minutes between administrations, followed by a single administration of the 6-minute walk test. Reliability and validity were estimated using Bland-Altman statistics, intraclass correlation coefficient (ICC2,1), paired t-test, and Spearman's rank correlation coefficient (ρ). RESULTS: The 1-minute sit-to-stand test exhibited excellent test-retest reliability with an ICC2,1 (CI) of 0.97 (0.95-0.99). The minimal metrically detectable change between separate measures on a subject for the difference in the measures to be considered real at the 95% confidence level was 2.9 repetitions and 11%, respectively. A learning effect of one repetition was observed between repeated measures. High construct validity was observed between the 1-minute sit-to-stand and 6-minute walk test (ρ = 0.78, p < .001). CONCLUSIONS: This study demonstrates the 1-minute sit-to-stand test as highly reliable, with an 11% change indicating a true outcome change. It also demonstrates robust construct validity compared to the 6-minute walk test. The 1-minute sit-to-stand test appears feasible for assessing functional capacity in well-functioning individuals with systemic sclerosis, but prior familiarization with the task is recommended, as a small learning effect was observed with one repetition.

Waking Up in Pain: a prospective unselected cohort study of pain in 3702 patients immediately after surgery in the Danish Realm.

BACKGROUND: Acute and persistent pain after surgery is well described. However, no large-scale studies on immediate postoperative pain in the operating room (OR) exist, hindering potential areas of research to improve clinical outcomes. Thus, we aimed to describe the occurrence and severity of immediate postoperative pain in a large, unselected cohort. METHODS: This was a prospective cohort study, encompassing all procedures in 31 public hospitals in the Danish Realm, during a 5-day period including the weekend. Data on procedures and anesthesia were collected and the main outcome was occurrence of moderate or severe pain in the OR. Secondary outcomes included pain, sedation and nausea in the OR or during the first 15 min in the postanesthesia care unit (PACU) including relevant risk factors. Descriptive and logistic regression statistics were used. RESULTS: A total of 3675 procedures were included for analysis (87% inclusion rate). Moderate or severe pain occurred in 7.4% (95% CI 6.5% to 8.3%) of cases in the OR immediately after awakening, rising to 20.2% in the OR and/or PACU. Large intraprocedure and interprocedure variations occurred (0.0%-37.5%), and in 20% of cases with epidural-general anesthesia patients experienced moderate or severe pain. Independent risk factors were female sex, younger age, preoperative pain, daily opioid use and major surgical procedures. CONCLUSION: Moderate or severe pain in the immediate postoperative phase occurred in 20% of all cases with procedure and anesthesiological technique variations, suggesting a need for identification of relevant procedure-specific risk factors and development of preventive treatments. TRIAL REGISTRATION NUMBER: RoPR ID 43191.

Overdoses with Aripiprazole: Signs, Symptoms and Outcome in 239 Exposures Reported to the Danish Poison Information Centre.

The aim of this study was to characterize the clinical signs and symptoms of exposures to aripiprazole overdoses. We retrospectively identified all aripiprazole exposures reported to the Danish Poison Information Centre (DPIC) from June 2007 to May 2015. Information concerning demographics, ingested dose and symptoms was extracted from the DPIC database and medical records. Information on death and admission to hospital was obtained from Danish national registers. We analysed 239 cases, 86 concerning single-drug exposures to aripiprazole, and 153 cases where aripiprazole had been taken with at least one other substance (mixed-drug). The median ingested aripiprazole dose was 105 mg (IQR: 50-1680 mg) in the single-drug exposure group and 120 mg (IQR: 60-225 mg) in the mixed-drug exposure group. The most commonly reported symptom was light sedation, reported in 63% of the single-drug group and 50% of the mixed-drug exposure group. There were no malignant arrhythmias or ECG abnormalities after single-drug exposures. No deaths were recorded in relation to the intake. We found a long-term mortality rate of 13 deaths per 1000 person-years (95% CI: 7; 23 per 1000 person-years), which is significantly higher than in an age- and gender-matched background population. In conclusion, we found that aripiprazole overdoses had few and mild symptoms predominantly related to the sedative properties. We detected a benign cardiovascular safety profile and no new safety concerns. Our findings may support an increased threshold of 300 mg for hospital admission after a single-drug exposure with aripiprazole and symptoms not worse than light sedation.

Dynamics of cancerous tissue correlates with invasiveness.

Two of the classical hallmarks of cancer are uncontrolled cell division and tissue invasion, which turn the disease into a systemic, life-threatening condition. Although both processes are studied, a clear correlation between cell division and motility of cancer cells has not been described previously. Here, we experimentally characterize the dynamics of invasive and non-invasive breast cancer tissues using human and murine model systems. The intrinsic tissue velocities, as well as the divergence and vorticity around a dividing cell correlate strongly with the invasive potential of the tissue, thus showing a distinct correlation between tissue dynamics and aggressiveness. We formulate a model which treats the tissue as a visco-elastic continuum. This model provides a valid reproduction of the cancerous tissue dynamics, thus, biological signaling is not needed to explain the observed tissue dynamics. The model returns the characteristic force exerted by an invading cell and reveals a strong correlation between force and invasiveness of breast cancer cells, thus pinpointing the importance of mechanics for cancer invasion.