Semirecumbent Position Research Articles

Evaluation of gastric contents using ultrasound in full-term pregnant women fasted for 8h: a prospective observational study.

We aimed to evaluate the gastric volume and contents after an 8-h fasting period in full-term, non-laboring, pregnant women following a standardized meal. In this prospective observational study, we included full-term pregnant women scheduled for elective cesarean delivery. The participants were instructed to fast after a standardized meal (apple juice, bread, and cheese). Participants were scanned in the semi-recumbent and right-lateral positions 8h after the standardized meal. The primary outcome was the proportion of patients with gastric volume > 1.5mLkg-1 calculated by two equations. Secondary outcomes included the antral cross-sectional area and gastric volume. Data are expressed as frequency (%, 95% confidence interval [CI]), mean ± standard deviation (95% CI of the mean), or median (quartiles) as appropriate. Forty-one women were available for the final analysis. For the primary outcome, one participant (2.4%, 95% CI of 0.06 to 12.8%) had gastric volume > 1.5mLkg-1, and none had solids in the antrum. For the secondary outcomes, the mean (95% CI of the mean) of the antral cross-sectional area was 2.11 ± 0.72 (1.88 to 2.34) cm2 and 4.08 ± 1.80 (3.51 to 4.65) cm2 during the semi-recumbent and right-lateral position, respectively. The median (quartiles) gastric volume was 0.53 (0.32, 0.66) mLkg-1 and 0.33 (0.13, 0.52) mLkg-1 as estimated by Perlas et al. and Roukhomovsky et al. equations, respectively. After 8-h fasting following a standardized meal, full-term pregnant non-laboring women are less likely to have a high residual gastric volume.

Influence of Total Body Irradiation Dose Rate on Idiopathic Pneumonia Syndrome in Pediatric Patients With Acute Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation

<h3>Purpose/Objective(s)</h3> To evaluate the relationship between total body irradiation (TBI) and other factors in the development of idiopathic pneumonia syndrome (IPS) in pediatric patients undergoing allogeneic hematopoietic cell transplantation (HCT) for acute leukemia. <h3>Materials/Methods</h3> Between 2006-2019, 121 pediatric patients with acute leukemia (84 lymphoblastic, 37 myeloid), ranging in age from 1 to 21 years (median 12), underwent allogeneic HCT at a single institution with matched sibling (n = 33), single unrelated cord blood (sUCB; n = 57), or double unrelated cord blood (dUCB; n = 31) donor. Pretransplantation conditioning included cyclophosphamide (100-120 mg/kg) with (n = 89) or without fludarabine (75 mg/m²) (n = 32). TBI was delivered in 8 b.i.d. fractions of 1.65 Gy over 4 days via opposed lateral beams of 6, 18, or 25 MV prescribed to midplane at umbilicus, with the patient in a semi-recumbent position, and without lung shielding. Aluminum lung compensator was utilized if predicted mid-lung point dose was ≥3% higher than prescription dose (n = 28). Dose rate was specified at 9-20 cGy/min and depended on linear accelerator availability. Patients were stratified by receipt of high-dose-rate (HDR; > 15 cGy/min; 36%) or low-dose-rate (LDR; ≤15 cGy/min; 64%) delivery. IPS was defined as pulmonary injury based on clinical symptoms, radiographic evidence, or pulmonary function testing within 100 days of HCT in the absence of concurrent infection. The association between treatment factors and IPS was examined. <h3>Results</h3> Overall, IPS developed in 22 (18%) patients from day 6 to 83 (median 20) after HCT. On univariate analysis, factors associated with IPS included donor type (matched sibling 12%, sUCB 12%, dUCB 35%, <i>P</i> < 0.01), HDR TBI (35% vs 9% for LDR, <i>P</i> < 0.01), and lower beam energy (35% for 6 MV and 15% for 18/25 MV, <i>P</i> = 0.04). The finding of beam energy significance is likely the result of the 6 MV cohort having a greater dose rate (median 16 cGy/min) than the 18/25 MV cohort (11 cGy/min). On competing risk regression analysis, the pre-specified factors of dose rate, beam energy, lung compensator, age, HCT comorbidity index, and donor type were included in the model. All factors except age (hazard ratio [HR] 1.09, <i>P</i> = 0.20) and lung compensator (HR 1.8, <i>P</i> = 0.17) showed an independent statistically significant association with IPS. Kaplan-Meier estimated 1-year survival was 73% for the entire cohort. Time-dependent effect of IPS did not show an association with overall survival (HR 1.2, <i>P</i> = 0.76). <h3>Conclusion</h3> TBI dose rate is an important variable in the risk of pulmonary toxicity in children treated with allogeneic HCT. TBI dose rates ≤15 cGy/min reduced the risk of posttransplantation IPS and should be strongly considered as an easily implemented parameter in pre-transplantation TBI-based conditioning.

The effect of melatonin on glucose tolerance, insulin sensitivity and lipid profiles after a late evening meal in healthy young males.

The suppression of melatonin by light at night (LAN) has been associated with a disruption of SCN function and biological processes. This study aimed to explore the impact of melatonin on glucose and lipid metabolism before and after a late evening meal. Nine healthy male participants (26 ± 1.3 years, BMI 24.8 ± 0.8 kg/m2 (mean ± SD) were randomly categorised into a three‐way cross‐over design protocol: light (>500 lux) (LS), dark (<5 lux) + exogenous melatonin (DSC) and light (>500 lux) + exogenous melatonin (LSC). All participants were awake in a semi‐recumbent position during each clinical session, which started at 18 00 h and ended at 06:00 h the following day. The meal times were individualised according to melatonin onset estimated from the participants' 48‐h sequential urine collection. The administration of exogenous melatonin was conducted 90 min before the evening meal. Saliva and plasma samples were collected at specific time points to analyse the glucose, insulin, NEFAs, TAGs, cortisol and melatonin levels. Participants demonstrated a significant reduction in postprandial plasma glucose, insulin and TAGs levels in the presence of melatonin (LSC and DSC) compared to LS (p = .002, p = .02 and p = .007, respectively). Pre‐prandial plasma NEFAs were significantly lower in LS than DSC and LSC as melatonin rose (p < .001). Exogenous melatonin administrated before an evening test meal improved glucose tolerance, insulin sensitivity and reduced postprandial TAGs. This study could have implications for shift workers who may have lower melatonin levels at night due to light suppression.

The effects of the 45° semi-recumbent position on the clinical outcomes of mechanically ventilated patients: a systematic review and meta-analysis study.

A meta-analysis was conducted to investigate the effects of the 45° semi-recumbent position on the clinical outcomes of mechanically ventilated patients. The PubMed, Embase, and Cochrane medical databases were searched using the keywords "45°", "head-of-bed elevation", and "semi-recumbent". All relevant randomized controlled trials (RCTs) published between 2005 and 2021 were obtained. The Cochrane system for randomized intervention was adopted and the RevMan 5.3.5 software was used to construct forest plots and funnel plots to assess the risk of bias for the included studies. A total of 128 literatures were initially screened for this meta-analysis, and 7 studies were finally included, with a total of 740 patients. Meta-analysis revealed that the incidence of ventilator-associated pneumonia (VAP) was significantly lower in patients in the 45° semi-recumbent position compared to patients in the 30° semi-recumbent position [odds ratio (OR) =0.48; 95% confidence interval (CI): 0.28 to 0.84; Z=2.59; P=0.009]. Furthermore, the incidence of gastric reflux was significantly lower in patients in the 45° semi-recumbent position compared to patients in the 30° semi-recumbent position (OR =0.50; 95% CI: 0.27 to 0.96; Z=2.09; P=0.04). Meta-analysis demonstrated that the incidence of pressure sores was significantly higher in patients in the 45° semi-recumbent position compared to patients in the 30° semi-recumbent position (OR =1.88; 95% CI: 1.05 to 3.36; Z=2.11; P=0.03). The 45° semi-recumbent position can reduce the incidence of VAP and gastric reflux in patients undergoing mechanical ventilation (MV), but it may also increase the risk of pressure sores. Thus, consideration should be made based on a comprehensive understanding of the patient's condition and physical state.

Abstract P204: Sinusoidal Galvanic Stimulation Improves Orthostatic Symptoms In Patients With Postural Tachycardia.

Postural Tachycardia Syndrome (POTS) is characterized by frequent orthostatic symptoms and excessive heart rate increase (&gt;= 30 bpm) on standing in the absence of orthostatic hypotension for more than 6 months. We and others have described a vestibulo-sympathetic reflex that can be engaged by galvanic vestibular stimulation to modulate sympathetic activity (Biaggioni et al., 2000; Kaufmann et al., 2002; Monahan &amp; Ray, 2002; Ray &amp; Carter, 2003, Bent, Macefield et al. 2006). We hypothesize that habituation to sinusoidal galvanic vestibular stimulation will improve orthostatic tolerance. We studied 6 patients with POTS (30.5+/6.0 years, BMI 22.8+/-2.9 kg/m 2 ) in two sessions using sinusoidal galvanic vestibular stimulation (sGVS 0.025 Hz, 2mA) or sham (0.01 mA). Stimulation was applied near mastoid process for 30 min in semi-recumbent position before orthostatic challenge. Patient were upright for a maximum of 15 minutes after each stimulation. Orthostatic change in Vanderbilt Orthostatic Symptom Score (dVOSS), orthostatic heart rate increase (dHR) and blood pressure response were recorded. Non-parametric Wilcoxon test for paired measures with significance level p&lt;0.05 was used. sGVS stimulation reduced overall orthostatic symptom score (dVOSS sham: 32.5+/-9.3 bpm vs dVOSS sGVS: 10.5+/-5.5, p=0.03) and tended to reduce orthostatic HR increase (dHR sham: 65.83+/-11.5 vs dHR sGVS: 46.5+/-10.7 bpm, p=0.06). Blood pressure and tilt time did not change. This pilot study suggests that habituation to sinusoidal vestibular could be used to improve orthostatic symptoms and orthostatic tolerance.

Effect of leg lift on stroke volume index in children 11-17 years old before and after induction of general anesthesia.

Fluid administration in ERAS is one component which anesthesiologists have control. Change in stroke volume index (SVI) is used to assess fluid responsiveness. This study sought the effect of perioperative fluid responsiveness in pediatric patients. The Cheetah NICOM™ (noninvasive CO monitor) was employed because of correlation with other CO monitors. The Cheetah NICOM™ is an FDA-approved device in adults. Its indications in children are unknown. 24 enrolled patients (age 11-17) were ASA 1 or 2 without cardiopulmonary disease. The study examined changes in SVI, HR, SBP, and DBP between the semi-recumbent and legs lifted positions, both awake and after anesthesia. Each patient had baseline vital signs measured and fluid responsiveness determined with the Cheetah NICOM™ monitor. Stroke volume index (SVI) was measured in both the semi-recumbent position and after passive leg lift. Measurements were repeated immediately after induction of general anesthesia. Twenty-one of 24 patients received inhalation induction with sevoflurane and three patients received intravenous propofol followed by sevoflurane. Airway management included intubation in 19 of 24 and a laryngeal mask airway (LMA) in five of 24 patients. There was a 25% increase in SVI after leg lift from 54.8ml/m2 to 68.0ml/m2 in awake patients (p &lt; 0.001). Diastolic pressure decreased by 15.4% from 67.9mmHg to 58.2mmHg from semi-recumbent position and leg lift, respectively (p=.004). No significant change in heart rate or SBP was found. Following induction, patient SVI increased with leg lift by 25.6% from 42.6ml/m2 to 53.5ml/m2 after leg lift (p=.003). Heart rate decreased by 9.3% and SBP increased 2.8% with leg lift. 96% of normal 11-17-year-old children were fluid responsive while awake and 79% after induction of general anesthesia.

Continuous Lower Abdominal Compression a Possible Therapeutic Intervention in ARDS

We report the case of sixty-years-old men who necessitated intubation and mechanical ventilation for severe COVID-19. After 3 days under mechanical ventilation, in semi recumbent position, despite being ventilated with 5.5 ml/kg/IBW and 8 cmH2O of positive end expiratory pressure (PEEP), deeply sedated and paralyzed, his plateau pressure (Pplat) was markedly elevated at 41 cmH2O.

The Effect of Changing Arterial Transducer Position on Stroke Volume Measurements Using FloTrac System Version 4.0: A Pilot Experimental Study.

We conducted a pilot study using an experimental study protocol to evaluate the measurement error of arterial pulse contour analysis-derived stroke volume due to improper transducer leveling during the passive leg raising test and the impact of such error on the determination of fluid responsiveness. Prospective observational study. A medical-surgical ICU at a tertiary referral center in Kobe, Japan. Consecutive critically ill adult patients using the FloTrac system Version 4.0 (Edwards Lifesciences, Irvine, CA) for hemodynamic monitoring between September 1, 2018, and November 31, 2018. None. Using 20 patients, we estimated the change in the zero-reference level of an arterial transducer during head-down tilting as the vertical distance between the zero-reference levels of the transducer in the 45° semi-recumbent and supine positions. Using the FloTrac system Version 4.0, we recorded the hemodynamic variables every 20 seconds for 180 seconds at each of the following three points: 1) baseline, 2) after the transducer was elevated by the predetermined distance, and 3) after the transducer had returned to baseline. With respect to the predetermined change in the transducer level, a mean value of 18 ± 3 cm resulted in an increase in stroke volume measurement (mean value, 11 mL/beat; 95% CI, 10-13). This value corresponded to 20% (95% CI, 18-23%) of the baseline value 20 seconds after changing the transducer level. A significant correlation was observed between the predetermined change in the transducer level and the increase in the measured stroke volume (r 2 = 0.58; p < 0.001). When using the FloTrac system Version 4.0, a rapid increase in stroke volume was observed after elevating the arterial transducer. Clinicians and researchers are advised that proper leveling of the arterial transducer is necessary in order to accurately assess the change in arterial pulse contour analysis-derived stroke volume during the passive leg raising test.

Paradoxical Effect of Chest Wall Compression on Respiratory System Compliance: A Multicenter Case Series of Patients With ARDS, With Multimodal Assessment

Paradoxical Effect of Chest Wall Compression on Respiratory System Compliance: A Multicenter Case Series of Patients With ARDS, With Multimodal Assessment

Comparison of Changes in PPV Using a Tidal Volume Challenge with a Passive Leg Raising Test to Predict Fluid Responsiveness in Patients Ventilated Using Low Tidal Volume.

BackgroundTidal volume challenge pulse pressure variation (TVC-PPV) is considered one of the recent reliable dynamic indices of fluid responsiveness (FR); also, passive leg raising (PLR)-induced changes in cardiac output (CO) detected by echocardiography are considered a reliable reversible self-fluid challenge test; many patients share eligibility for both tests.ObjectivesThe study aimed to compare the sensitivity and specificity of both tests for the prediction of FR in mechanically ventilated patients with hemodynamic instability.MethodsWe studied 46 patients. Hemodynamic parameters including PPV and CO (detected by velocity time integral (VTI) using echocardiography) recorded at tidal volume (VT) of 6 mL/kg/ideal body weight (IBW) in semi-recumbent position then recorded again after one-minute increase in TV from 6 to 8 mL/kg/IBW then recorded with PLR at TV of 6 mL/kg/IBW and finally with actual volume expansion in semi-recumbent position by 4 ml/kg bolus of crystalloid solution to define actual responders with increase of cardiac output of 15% or more.ResultsSixteen patients were responders, and thirty patients were nonresponders; responders had significant increase in PPV with TVC 6 to 8 ml/kg/IBW with best cutoff value of 3.5 with a sensitivity of 93.8% and a specificity of 93.9%. PLR test-induced changes in CO had a sensitivity of 93.9% and a specificity of 86.7% with statistically best cutoff value of 6.5% increase in CO, but sensitivity was 75% at cutoff value of 10% increase in CO. Other parameters like PPV, PPV changes with PLR test, and PPV changes with fluid expansion were less sensitive indicators.ConclusionFR in patients with hemodynamic instability and mechanically ventilated with low tidal volume strategy can be efficiently predicted when PPV increases more than 3.5 with tidal volume challenge and when PLR induces 6.5% increase in CO monitored through VTI method by Doppler echocardiography, and both tests are equally reliable.How to cite this articleElsayed AI, Selim KAW, Zaghla HE, Mowafy HE, Fakher MA. Comparison of Changes in PPV Using a Tidal Volume Challenge with a Passive Leg Raising Test to Predict Fluid Responsiveness in Patients Ventilated Using Low Tidal Volume. Indian J Crit Care Med 2021;25(6):685–690.

Reliability of a Protocol to Elicit Peak Measures Generated by the Lower Limb for Semi-recumbent Eccentric Cycling.

Semi-recumbent eccentric (ECC) cycling is increasingly used in studies of exercise with healthy and clinical populations. However, workloads are generally prescribed using measures obtained during regular concentric cycling. Therefore, the purpose of the study was to quantify the reliability of measures derived from a protocol that elicited peak ECC torque produced by the lower limb in a semi-recumbent position. Experiments were carried out on a dynamometer in a seated, semi-recumbent position identical to that of a custom-built ECC cycle, a modified Monark recumbent cycle. Thirty healthy participants completed two testing sessions. Each session comprised three series of six repetitions of a peak ECC torque protocol (PETP) on an isokinetic dynamometer. Absolute and relative reliability of peak torque, power, angle of peak torque, and work (recorded for each repetition) was determined using coefficient of variation (CV) and intraclass correlation coefficient (ICC), respectively. Ratings of perceived exertion (RPE), muscle soreness, and perceived effort (PE) were recorded pre-PETP, immediately post-PETP, and 1-min post each PETP. The protocol showed absolute reliability values <15% for mean peak (CV = 10.6–12.1) torque, power (CV = 10.4–12.3), angle of peak torque (CV = 1.2–1.4), and work (CV = 9.7–12.1). Moderate to high between-test relative reliability is reported for mean and highest torque (ICC = 0.84–0.95; ICC = 0.88–0.98), power (ICC = 0.84–0.94; ICC = 0.89–0.98), and work (ICC = 0.84–0.93; ICC = 0.88–0.98), respectively. Within-session peak torque, peak power, and peak work showed high relative reliability for mean (ICC = 0.92–0.95) and highest (ICC = 0.92–0.97) values. Overall, the PETP test provides a reliable way of determining peak ECC torque specific to semi-recumbent ECC cycling that may be used to prescribe workloads for this form of exercise.

Role of head-of-bed elevation in preventing ventilator-associated pneumonia bed elevation and pneumonia.

Elevating the head of bed (HOB) to 30° to 45° is an evidence-based recommendation to prevent ventilator-associated pneumonia (VAP). However, the available scientific data are inconclusive regarding the optimal degree of HOB elevation which is safe and effective for mechanically ventilated patients. To investigate the impact a of semirecumbent position at 30° and 45°on the development of VAP as compared with aHOB elevation to <30°. A 5-day, single centre, prospective, randomized, controlled, parallel group, three-arm study was conducted in adult patients on mechanical ventilation staying in the intensive care unit. Patients were randomly placed in <30°, 30°, or 45° HOB elevation position on the day of intubation and followed up for 5 days. They were assessed in terms of the development of microbiologically confirmed VAP (by the culture of endotracheal aspirate) over the study period. Sixty patients (20 in each arm) completed the study. VAP occurred in 55%, 25%, and 20% of patients in the HOB elevation to <30°, 30°, and 45°study arms, respectively. The frequency of VAP was significantly lower in the 45° compared with the <30° study arm (P=.022); there were no significant differences between the <30° and 30° as well as the 45° and 30° study groups. Unlike the frequency of VAP, the timing of the VAP (early or late) was not dependent on the degree of HOB elevation (P=.703). Keeping the mechanically ventilated patients in a semirecumbent position as close to 45°as possible should be the goal to prevent the development of VAP. The backrest elevation <30° should be avoided unless medically indicated. The study results reaffirm the crucial role of patient positioning, an essential nursing care intervention, in preventing VAP. Intensive care nurses can contribute to improving the VAP rates and outcomes by placing and keeping the patients in the correct position.

Lateral Positioning in COVID-19 Pneumonia, A Cross Sectional Study Among 300 Patients

Background: The efficacy of lateral positioning in lung pathologies have been evaluated in few studies, though none give a definitive conclusion. We have performed this study on 300 COVID-19 infected patients to determine the improvement in oxygen levels on lateral decubitus in comparison to semi-recumbent position, to correlate with lung imaging findings, and also to assess these correlations within various severities of illness.Methods: In this cross sectional study we recorded spO2 of 300 spontaneously breathing, non intubated hemodynamically stable adult COVID-19 RTPCR positive patients on semi-recumbent, left decubitus and right decubitus positions. They were segregated into three severity groups, based on clinical signs, semi-recumbent oxygen levels, respiratory rate and lung findings, and data analysed separately in each group. Findings: 194 (64%) out of all 300 participants had improved oxygenation on lateral decubitus. The changes ranged from 2% drop to 5% gain in spO2 levels, while on right decubitus it varied from a 3% drop to 7% gain. 92.3% of patients who improved on left lateral positioning had infiltrates predominantly in right lung, and 69.1% patients with improvement on right lateral had left lung involved. Similar observations were made in all three severity groups and all correlations were statistically significant with pInterpretation: Significant proportion of patients were noted to have improvement on lateral positioning. In patients unable to lie prone, caregivers may be educated to make patients preferentially lie on their sides with lesser lung involvement for better improvement in oxygen levels and a faster recovery.Funding: No funds used for this study.Declaration of Interests: None.Ethics Approval Statement: This is an observational cross sectional study conducted on 300 hemodynamically stable, spontaneously breathing, non-intubated adult patients with COVID-19 pneumonia in COVID ward of Govt Kilpauk hospital. This study took place for six months after Ethical committee approval.

The semirecumbent position for high-resolution esophageal manometry. Results of a feasibility study.

Normative values for high-resolution manometry (HRM) have been obtained with the patient lying supine. The aim of the study was to compare supine, semirecumbent and sitting positions during HRM in terms of variation in normative metrics, diagnostic yield, and patient's comfort. A prospective, single-center feasibility study was planned in consecutive patients referred to the esophageal function laboratory. In each of the three positions, 10 consecutive 5 ml water swallows and three 10 ml multiple rapid swallows were administered. Validated reflux questionnaires were administered prior to the test, and a visual analogue scale (VAS) assessing the patient's comfort after the test. Twenty patients presenting with gastroesophageal reflux symptoms completed the study protocol. The intra-abdominal segment of the lower esophageal sphincter was significantly longer in the sitting position (P = 0.013), and the multiple rapid swallow distal contractile integral was lowest in the supine position (P = 0.012). The VAS comfort score did not significantly differ in the three body positions (P = 0.295). The concordance in the final diagnosis was 80% for semirecumbent vs. sitting (kappa = 0.15; P = 0.001), 70% for supine vs. sitting and 65.0% for semirecumbent vs. supine. Compared to the supine position, both the semirecumbent and sitting position seems to provide similar advantages. HRM metrics and the final manometric diagnosis may be affected by body position, but complementary maneuvers, such are the rapid drink challenge, can resolve diagnostic discrepancies and improve the overall accuracy of the test.

Brief intermittent pressure off-loading on skin microclimate in healthy adults – A descriptive-correlational pilot study

AimThis study examined microclimate changes to the skin as a result of pressure over a 1 h period. The results were compared to skin parameter results following brief consecutive off-loading of pressure-prone areas. DesignA descriptive-correlational pilot study was undertaken. MethodA convenience sample of 41 healthy adults aged 18–60 years was recruited. Participants engaged in four 1 h data collection sessions. The sessions were conducted in both semi-recumbent and supine positions. Measures of erythema, melanin, stratum corneum hydration, and skin temperature were taken at pressure-prone areas at baseline and after 1 h in an uninterrupted method (continuous pressure-loading) and every 10 min in an interrupted method (brief off-loading). The Corneometer and Mexameter (Courage + Khazaka Electronics GMbH, 2013) and Exergen DermaTemp DT-1001 RS Infrared Thermographic Scanner (Exergen Corporation, 2008) provided a digital appraisal of skin parameters. Intraclass correlation coefficients (ICC) were calculated to indicate test-retest reliability and absolute agreement of results between the two methods. ResultsStrong agreement between the interrupted and uninterrupted method was observed with ICCs ranging from 0.72 to 0.99 (supine) and 0.62–0.99 (semi-recumbent). Endpoint measures tended to be higher compared to baseline measures for all skin parameters. Differences in skin parameters results by anatomical location were evident particularly for erythema and stratum corneum hydration; the elbows and heels yielded lower scores compared to the sacrum. Erythema had the most variation across methods. The supine and semi-recumbent positions had negligible effect on measured skin parameters. ConclusionsMinimal variation between skin parameter results indicates that brief off-loading in the interrupted method did not significantly change the outcomes; minor shifts in positioning do not alter changes to the skin from pressure. Skin parameters varied by anatomical location and changed over a 1 h period of pressure-loading. Relevance to clinical practiceBiophysical techniques may be able to assist accurate assessment of skin microclimate and skin colour. As brief off-loading (interruptions) to enable skin parameter measurement does not alter skin readings, researchers can proceed with some confidence regarding the use of this protocol in future studies assessing skin parameters. This study data provides a library of cutaneous changes at pressure-prone areas of healthy adults and is expected to inform innovative approaches to pressure injury risk assessment.

Infection prevention practices in the United States, the Netherlands, Switzerland, and Japan: Results from national surveys.

To assess the extent to which evidence-based practices are regularly used in acute care hospitals in different countries. Cross-sectional survey study. Participants and setting: Infection preventionists in acute care hospitals in the United States (US), the Netherlands, Switzerland, and Japan. Data collected from hospital surveys distributed between 2015 and 2017 were evaluated to determine the use of practices to prevent catheter-associated urinary tract infection (CAUTI), central-line-associated bloodstream infection (CLABSI), ventilator-associated pneumonia (VAP), and Clostridioides difficile infection (CDI). Descriptive statistics were used to examine hospital characteristics and the percentage of hospitals reporting regular use of each infection prevention practice. Survey response rates were 59% in the United States, 65% in the Netherlands, 77% in Switzerland, and 65% in Japan. Several recommended practices were used in the majority of hospitals: aseptic catheter insertion and maintenance (CAUTI), maximum sterile barrier precautions (CLABSI), semirecumbent patient positioning (VAP), and contact precautions and routine daily cleaning (CDI). Other prevention practices for CAUTI and VAP were used less frequently, particularly in Swiss and Japanese hospitals. Established surveillance systems were also lacking in Dutch, Swiss and Japanese hospitals. Most hospitals in the United States, the Netherlands, Switzerland, and Japan have adopted certain infection prevention practices. Clear opportunities for reducing HAI risk in hospitals exist across all 4 countries surveyed.

278 Assessing effects of lateral tilt on cardiac output using a Non-invasive technique

Aortocaval compression (ACC), or supine hypotension syndrome, may lead to adverse fetal outcomes secondary to changes in maternal hemodynamics. Lateral tilt has been advocated to address ACC. We aim to determine the maternal position with the least effect on maternal hemodynamics. Term pregnant women scheduled for induction of labor were first placed in semi-recumbent (baseline), followed by supine, 15o and 30 o left lateral tilt (LLT), each for 20 minutes period, after which hemodynamic parameters were measuring using non-invasive cardiac output monitor NICOM. Friedman ANOVA with Dunn’s test multiple comparison test were used for analysis. P<0.05 was considered statistically significant. Forty subjects were included (Table). Cardiac index (CI) significantly increased in the supine position compared with baseline (median [range]: 3.8 [2.8-5.2] vs 4.2 [2.9-5.9] L/min/m2). CI also increased in 15o and 30 o left lateral tilt but did not reach statistical significance (Figure). Compared with baseline, stroke volume index (SVI) significantly increased (baseline: 43.7 [31.0-65.0]; supine: 49.5 [34.0-77.0]; 15o LLT: 49.8 [34.0-70.0] and 30o LLT: 49.9 [32.0-66.0] ml/m2; P<0.05 for all; Figure) while maternal heart rate significantly decreased in all 3 positions (baseline: 88 [70-106], supine: 85[63-99], 15o LLT: 81 [61-98] and 30o LLT: 80.0 [61-96] bpm; P<0.05 for all). Stroke volume variation (SVV) significantly decreased in all 3 positions (baseline: 12.9 [8.0-18.0], supine: 11.6 [7.0-17.0], 15o LLT: 11.6 [6.0-20.0] and 30o LLT 11.5 [7.0-20.0] %; P<0.05 for all). Subgroup analysis for BMI above or below 30 Kg/m2 showed similar results. Compared to semi-recumbent position, supine followed by left tilt position led to improvements in maternal hemodynamic parameters. The improvement in SVV, a measure of hypovolemia, indicates an increase in venous return and upper-right shift in the Frank-Starling curve. It is best to avoid semi-recumbent position in term pregnancies.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

The effect of reverse Trendelenburg position versus semi-recumbent position on respiratory parameters of obese critically ill patients: A randomised controlled trial.

To investigate the effect of reverse Trendelenburg position versus semi-recumbent position on respiratory parameters of obese critically ill patients. Reverse Trendelenburg position is recommended for obese patients; however, the effect among critically ill patients, especially those on mechanical ventilation, has limited study. Randomised, controlled pretest, repeated post-test trial with two parallel groups. The study started from 13 January 2020-12 March 2020. Adult critically ill patients with a body mass index ≥30 were randomly assigned by computer-generated randomisation to either reverse Trendelenburg position group (intervention) or semi-recumbent position group (active comparator control). Outcome measures were ventilation parameters (dynamic compliance, partial pressure of arterial carbon dioxide and minute volume) and oxygenation parameters (hypoxaemic index and partial pressure of arterial oxygen). Measures were assessed immediately before positioning and after positioning in 10 minutes, 20 minutes and 30 minutes. CONSORT checklist was used to report the current study. Four general intensive care units. One hundred and ten patients (55 patients in each group) completed the study. The reverse Trendelenburg position group had a higher improvement than the semi-recumbent position group as estimated by mean differences in their dynamic compliance, minute volume, partial pressure of carbon dioxide, partial pressure of oxygen and hypoxaemic index. Reverse Trendelenburg position improves obese patients' respiratory parameters more than semi-recumbent position. This study directs nurses to use the reverse Trendelenburg position, which is an important position for enhancing the parameters of ventilation and oxygenation of obese mechanically ventilated patients.

Exovent: a study of a new negative-pressure ventilatory support device in healthy adults.

Negative-pressure ventilation may have several advantages compared with positive-pressure ventilation. Negative-pressure ventilation simulates natural lung movements, does not require tracheal intubation and may reduce the incidence of barotrauma and adverse cardiovascular events. A group of engineers, doctors and nurses designed and bench-tested the Exovent, a new, lightweight, torso-only, negative-pressure ventilatory support system. We aimed to test the comfort, nursing acceptability and ventilatory support capabilities of the Exovent in healthy adult volunteers. We measured the effect of continuous negative extra-thoracic pressure on functional reserve capacity and the efficacy of ventilation produced by a combination of negative-pressure ventilation and negative end-expiratory pressure. Six members of the development team volunteered to test the device. The application of continuous negative extra-thoracic pressure did not change tidal volumes from baseline levels; however, functional reserve capacity increased by a mean (SD) of 1.1 (0.05) ml.kg-1 .cmH2 O-1 (p=0.0002). The combination of negative-pressure ventilation and negative end-expiratory pressure produced effective ventilation, with the resting tidal volume being exceeded by the application of -4 cmH2 O of extra-thoracic negative pressure. All the volunteers found the experience comfortable and none had ventilator dysynchrony. The Exovent allowed good nursing and monitoring access and was comfortable in both the semi-recumbent and prone positions. The Exovent delivered effective continuous negative extra-thoracic pressure and negative-pressure ventilation plus negative end-expiratory pressure to healthy adults. Further trials are needed to investigate the clinical utility of the device.

SARS-CoV-2 pneumonia succesfully treated with cpap and cycles of tripod position: a case report

BackgroundPneumonia induced by 2019 Coronavirus (COVID-19) is characterized by hypoxemic respiratory failure that may present with a broad spectrum of clinical phenotypes. At the beginning, patients may have normal lung compliance and be responsive to noninvasive ventilatory support, such as CPAP. However, the transition to more severe respiratory failure - Severe Acute Respiratory Syndrome (SARS-CoV-2), necessitating invasive ventilation is often abrupt and characterized by a severe V/Q mismatch that require cycles of prone positioning. The aim of this case is to report the effect on gas exchange, respiratory mechanics and hemodynamics of tripod (or orthopneic sitting position) used as an alternative to prone position in a patient with mild SARS-CoV-2 pneumonia ventilated with helmet CPAP.Case presentationA 77-year-old awake and collaborating male patient with mild SARS-CoV-2 pneumonia and ventilated with Helmet CPAP, showed sudden worsening of gas exchange without dyspnea. After an unsuccessful attempt of prone positioning, we alternated three-hours cycles of semi-recumbent and tripod position, still keeping him in CPAP. Arterial blood gases (PaO2/FiO2, PaO2, SaO2, PaCO2 and A/a gradient), respiratory (VE, VT, RR) and hemodynamic parameters (HR, MAP) were collected in the supine and tripod position. Cycles of tripod position were continued for 3 days. The patient had a clinically important improvement in arterial blood gases and respiratory parameters, with stable hemodynamic and was successfully weaned and discharged to ward 10 days after pneumonia onset.ConclusionsTripod position during Helmet CPAP can be applied safely in patients with mild SARS-CoV-2 pneumonia, with improvement of oxygenation and V/Q matching, thus reducing the need for intubation.