End-tidal carbon dioxide is better than arterial pressure for predicting volume responsiveness by the passive leg raising test

Purpose

In stable ventilatory and metabolic conditions, changes in end-tidal carbon dioxide (EtCO₂) might reflect changes in cardiac index (CI). We tested whether EtCO₂ detects changes in CI induced by volume expansion and whether changes in EtCO₂ during passive leg raising (PLR) predict fluid responsiveness. We compared EtCO₂ and arterial pulse pressure for this purpose.

Methods

We included 65 patients [Simplified Acute Physiology Score (SAPS)?II?=?57?±?19, 37 males, under mechanical ventilation without spontaneous breathing, 15?% with chronic obstructive pulmonary disease, baseline CI?=?2.9?±?1.1?L/min/m²] in whom a fluid challenge was decided due to circulatory failure and who were monitored by an expiratory-CO₂ sensor and a PiCCO2 device. In all patients, we measured arterial pressure, EtCO₂, and CI before and after a fluid challenge. In 40 patients, PLR was performed before fluid administration. The PLR-induced changes in arterial pressure, EtCO₂, and CI were recorded.

Results

Considering the whole population, the fluid-induced changes in EtCO₂ and CI were correlated (r ²?=?0.45, p?=?0.0001). Considering the 40 patients in whom PLR was performed, volume expansion increased CI ??15?% in 21 ??volume responders.?? A PLR-induced increase in EtCO₂ ??5?% predicted a fluid-induced increase in CI ??15?% with sensitivity of 71?% (95?% confidence interval: 48?C89?%) and specificity of 100 (82?C100)?%. The prediction ability of the PLR-induced changes in CI was not different. The area under the receiver-operating characteristic (ROC) curve for the PLR-induced changes in pulse pressure was not significantly different from 0.5.

Conclusion

The changes in EtCO₂ induced by a PLR test predicted fluid responsiveness with reliability, while the changes in arterial pulse pressure did not.     

Smart Bag vs. Standard bag in the temporary substitution of the mechanical ventilation

Objective

To compare in intubated patients manually ventilated in order to mirror the ventilator, the respiratory and hemodynamic effects induced by a bag device equipped with an inspiratory gas flow-limiting valve (Smart Bag, 0-Two Medical Technologies Inc., Mississauga, ON, Canada) and a Standard bag.

Design

Non-randomized crossover study comparing 13?respiratory and eight hemodynamically paired parameters. Eight intubated patients were manually ventilated, each by three different intensive care workers yielding 24 sets of data for comparison. Data were collected during two sessions of manual ventilation, first with the Standard bag and then with the Smart Bag. Between each session, the patient was reconnected to the ventilator until return to the baseline. Patients, included after coronary surgery, were sedated and paralyzed.

Setting

Intensive Care Unit, university hospital.

Results

Compared with Standard bag, the Smart Bag^® provided a decrease of inspiratory flow (23?±?4.7 vs. 47.3?±?16.5?l/min) with a decrease of peak pressure (13.3?±?2.9 vs. 21.9?±?7.3?cmH₂O) and tidal volume (9.4?±?2.8 vs. 12.4?±?2.7?ml/kg). While the expiratory time was similar, the inspiratory time increased (1.83?±?0.58 vs. 1.28?±?0.46?s) with the Smart Bag, limiting the respiratory rate (14?±?5 vs. 17?±?6?cycles/min) and the minute volume (8.8?±?2.9 vs. 14.4?±?4.9?l/min). Finally, it limited the fall of the ETCO₂ (27.9?±?5.1 vs. 24.3?±?5.7?mmHg) and probably the risks of severe respiratory alkalosis. The bags similarly affected hemodynamic states.

Conclusion

In intubated patients manually ventilated, the Smart Bag limits the risks of excessive airway pressure and the fall of the ETCO₂, with hemodynamic effects similar to those of the Standard bag.     

An optimized set-up for helmet noninvasive ventilation improves pressure support delivery and patient�Cventilator interaction

Objective

To test the effects on mechanical performance of helmet noninvasive ventilation (NIV) of an optimized set-up concerning the ventilator settings, the ventilator circuit and the helmet itself.

Subjects and methods

In a bench study, helmet NIV was applied to a physical model. Pressurization and depressurization rates and minute ventilation (MV) were measured under 24 conditions including pressure support of 10 or 20?cmH₂O, positive end expiratory pressure (PEEP) of 5 or 10?cmH₂O, ventilator circuit with ??high??, ??intermediate?? or ??low?? resistance, and cushion deflated or inflated. In a clinical study pressurization and depressurization rates, MV and patient?Cventilator interactions were compared in six patients with acute respiratory failure during conventional versus an ??optimized?? set-up (PEEP increased to 10?cmH₂O, low resistance circuit and cushion inflated).

Results

In the bench study, all adjustments simultaneously applied (increased PEEP, inflated cushion and low resistance circuit) increased pressurization rate (46.7?±?2.8 vs. 28.3?±?0.6?%, p?<?0.05), depressurization rate (82.9?±?1.9 vs. 59.8?±?1.1?%, p????0.05) and patient MV (8.5?±?3.2 vs. 7.4?±?2.8?l/min, p?<?0.05), and decreased leaks (17.4?±?6.0 vs. 33.6?±?6.0?%, p?<?0.05) compared to the basal set-up. In the clinical study, the optimized set-up increased pressurization rate (51.0?±?3.5 vs. 30.8?±?6.9?%, p?<?0.002), depressurization rate (48.2?±?3.3 vs. 34.2?±?4.6?%, p?<?0.0001) and total MV (27.7?±?7.0 vs. 24.6?±?6.9?l/min, p?<?0.02), and decreased ineffective efforts (3.5?±?5.4 vs. 20.3?±?12.4?%, p?<?0.0001) and inspiratory delay (243?±?109 vs. 461?±?181?ms, p?<?0.005).

Conclusions

An optimized set-up for helmet NIV that limits device compliance and ventilator circuit resistance as much as possible is highly effective in improving pressure support delivery and patient?Cventilator interaction.     

The use of end-tidal carbon dioxide monitoring in patients with hypotension in the emergency department

Background

The aim of this study was to determine the usefulness of end tidal carbon dioxide (ETCO₂) monitoring in hypotensive shock patients presenting to the ED.

Methods

This was a prospective observational study in a tertiary ED. One hundred three adults in shock with hypotension presenting to the ED were recruited into the study. They were grouped according to different types of shock, hypovolemic, cardiogenic, septic and others. Vital signs and ETCO₂ were measured on presentation and at 30-min intervals up to 120 min. Blood gases and serum lactate levels were obtained on arrival. All patients were managed according to standard protocols and treatment regimes. Patient survival up to hospital admission and at 30 days was recorded.

Results

Mean ETCO₂ for all patients on arrival was 29.07?±?9.96 mmHg. Average ETCO₂ for patients in hypovolemic, cardiogenic and septic shock was 29.64?±?11.49, 28.60?±?9.87 and 27.81?±?7.39 mmHg, respectively. ETCO₂ on arrival was positively correlated with systolic and diastolic BP, MAP, bicarbonate, base excess and lactate when analyzed in all shock patients. Early ETCO₂ measurements were found to be significantly lower in patients who did not survive to hospital admission (p?=?0.005). All patients who had ETCO₂????12mmHg died in the ED. However, normal ETCO₂ does not ensure patient survival.

Conclusion

The use of ETCO₂ in the ED has great potential to be used as a method of non-invasive monitoring of patients in shock.     

Knee area tissue oxygen saturation is predictive of 14-day mortality in septic shock

Purpose

Thenar eminence tissue oxygen saturation (StO₂) was developed to assess organ perfusion. However, mottling, a strong predictor of mortality in septic shock, develops preferentially around the knee. We aimed to evaluate the prognostic value of StO₂ measured around the knee in septic shock patients and compare it to thenar StO₂.

Methods

This was a prospective observational study in a tertiary teaching hospital. All consecutive patients with septic shock were included. Parameters were recorded when vasopressors were started (H0) and every 6?h during 24?h. Their predictive value was assessed on 14-day mortality.

Results

Fifty-two patients were included. SOFA score was 11 (9–15) and SAPS II was 56 (40–72). At 6?h after ICU admission (H6), mean arterial pressure, cardiac index, and central venous pressure were not different between non-survivors and survivors; but non-survivors had higher arterial lactate level (8.8?±?5.0 vs. 2.2?±?1.5?mmol/l, P?P?2 (62?±?20 vs. 72?±?9?%, P?=?0.03). At H6, StO₂ was lower in non-survivors; this difference was not significant for thenar StO₂ (70?±?15 vs. 77?±?12?%, P?=?0.10) but was very pronounced for knee StO₂ (39?±?23 vs. 71?±?12?%, P?2 was associated with a higher mottling score (P?P?R ²?=?0.2), and a lower urinary output (P?=?0.02, R ²?=?0.12).

Conclusion

After initial septic shock resuscitation, StO₂ measured around the knee is a strong predictive factor of 14-day mortality.     

Effects of exogenous hydrogen sulfide on brain metabolism and early neurological function in rabbits after cardiac arrest

Purpose

Some of the neuroprotective effects of hydrogen sulfide (H₂S) have been attributed to systemic hypometabolism and hypothermia. However, systemic metabolism may vary more dramatically than brain metabolism after cardiac arrest (CA). The authors investigated the effects of inhaled exogenous hydrogen sulfide on brain metabolism and neurological function in rabbits after CA and resuscitation.

Methods

Anesthetized rabbits were randomized into a sham group, a sham/H₂S group, a CA group, and a CA/H₂S group. Exogenous 80?ppm H₂S was administered to the sham/H₂S group and the CA/H₂S group which suffered 3?min of untreated CA by asphyxia and resuscitation. Effects on brain metabolism (cerebral extraction of oxygen (CEO₂), arterio-jugular venous difference of glucose [AJVD(glu)] and lactate clearance), S100B, viable neuron counts, neurological dysfunction score, and survival rate were evaluated.

Results

CEO₂, AJVD(glu), and lactate increased significantly after CA. Inhalation of 80?ppm H₂S significantly increased CEO₂ (25.04?±?7.11 vs. 16.72?±?6.12?%) and decreased AJVD(glu) (0.77?±?0.29 vs. 1.18?±?0.38?mmol/L) and lactate (5.11?±?0.43 vs. 6.01?±?0.64?mmol/L) at 30?min after resuscitation when compared with the CA group (all P?<?0.05). In addition, neurologic deficit scores, viable neuron counts, and survival rate were significantly better whereas S100B was decreased after H₂S inhalation.

Conclusions

The present study reveals that inhalation of 80?ppm H₂S reduced neurohistopathological damage and improves early neurological function after CA and resuscitation in rabbits. The increased CEO₂ and decreased AJVD(glu) and enhanced lactate clearance may be involved in the protective effects.     

Feasibility and safety of transradial approach for catheter ablation of idiopathic left ventricular tachycardia

Background

The feasibility and safety of the transradial approach for catheter ablation of idiopathic left ventricular tachycardia (ILVT) have not been evaluated. The aim of this study was to investigate the feasibility and safety of transradial approach for catheter ablation in ILVT patients.

Methods

Thirty consecutive ILVT patients with negative Allen??s test undergoing catheter ablation via transradial approach were enrolled to compare the safety and efficacy with 30 other ILVT patients who previously underwent catheter ablation via transfemoral approach.

Results

Ablation was successfully performed in all patients. In the transradial group, the total procedural and the fluoroscopy time (42.8?±?6.9?min and 9.7?±?1.9?min, respectively) were significantly shorter when compared with transfemoral group (52.8?±?8.4?min and 11.5?±?2.1?min, respectively) (both P?<?0.05). The two groups were similar in the number of current applications (4.1?±?0.8 vs. 4.4?±?1.1, P?>?0.05), the power energy (47.3?±?7.3 vs. 49.7?±?6.9?W, P?>?0.05), and the total duration of current application (110.3?±?15.6 vs. 112.3?±?16.5?s, P?>?0.05), respectively. The duration of hospitalization in transradial group was shorter than that in transfemoral group (4.1?±?0.9 vs. 5.8?±?1.1?days, P?<?0.05). During follow-up, there was no recurrence of tachycardia in all patients. One patient in transfemoral group developed access site complications while none occurred in the transradial group.

Conclusions

The transradial approach is feasible and safe for catheter ablation of ILVT.     

Transpulmonary thermodilution measurements are not affected by continuous veno-venous hemofiltration at high blood pump flow

Purpose

To assess whether continuous veno-venous hemofiltration (CVVH) with high blood pump flow alters the measurements of cardiac index (CI), global end-diastolic volume indexed (GEDVI), and extravascular lung water indexed (EVLWI) performed by transpulmonary thermodilution.

Methods

Sixty-nine patients were included if they were monitored by a PiCCO2 device and received CVVH through a femoral (n?=?62) or an internal jugular (n?=?7) dialysis catheter. The blood pump flow was set at 250?mL/min (n?=?31) or 350?mL/min (n?=?38) and the filtration flow at 6,000?mL/h. A first set of data was collected with a first transpulmonary thermodilution (TD_on). The blood pump was stopped and the continuous CI derived from pulse contour analysis was recorded (PC_off). A second data set (TD_off) was collected before and a last one (TD_on-last) after restarting the blood pump.

Results

$ {\text{CI}}_{{{\text{TD}}_{\text{on}} }} $ , $ {\text{CI}}_{{{\text{PC}}_{\text{off}} }} $ , $ {\text{CI}}_{{{\text{TD}}_{\text{off}} }} $ , and $ {\text{CI}}_{{{\text{TD}}_{{{\text{on}} - {\text{last}}}} }} $ were not significantly different in patients with a femoral dialysis catheter (3.49?±?0.96, 3.51?±?0.96, 3.51?±?0.99, and 3.44?±?1.00?L?min^?1?m^?2, respectively). This was observed with a blood pump flow at 350?mL/min and at 250?mL/min. In these patients with a femoral dialysis catheter, GEDVI did not significantly change when the blood pump was stopped. EVLWI significantly decreased when the blood pump was stopped but to a non-clinically relevant extent (?0.3?±?0.8?mL/kg). No significant changes in CI, GEDVI, and EVLWI were observed in patients with an internal jugular dialysis catheter over the study period.

Conclusions

CVVH with a high blood flow pump does not alter the transpulmonary thermodilution measurements of CI, GEDVI, and EVLWI.     

Initial Experience with the Radiotracer Anti-1-amino-3-[18F]Fluorocyclobutane-1-Carboxylic Acid (Anti-[18F]FACBC) with PET in Renal Carcinoma

Purpose

Assessment of renal masses with conventional imaging may be challenging. Anti-1-amino-3-[¹⁸F]fluorocyclobutane-1-carboxylic acid (anti-[18F]FACBC) is a synthetic l-leucine analog with relatively little renal excretion. The present study examines anti-[¹⁸F]FACBC positron emission tomography uptake in patients with renal masses.

Procedures

Six patients with seven renal lesions were imaged dynamically for 2 h after injection of 10–10.9 mCi (370–403 MBq) anti-[¹⁸F]FACBC. Lesions were evaluated qualitatively and quantitatively and correlated with histology.

Results

Four clear cell and one Rosai–Dorfman lesion were hypo/isointense to normal cortex; two papillary lesions in the same patient were hyperintense. Mean SUV_max?±?SD at 30 min was 2.8?±?0.24 for clear cell carcinomas and 4.5?±?1.7 for papillary cell lesions. Mean SUV_max/SUV_mean ratios?±?SD of lesion to normal cortex at 30 min was 1.15?±?0.19 for the clear cell carcinomas and 2.3?±?0.84 for papillary cell.

Conclusions

In this small patient sample, relative amino acid transport compared with renal cortex is elevated in renal papillary cell carcinoma but not in clear cell carcinoma.     

Patterns of physical activity participation across the cancer trajectory in colorectal cancer survivors

Purpose

The purpose of the present study was to explore the participation in physical activity (PA) by colorectal cancer survivors across cancer trajectories and based on selected demographic and medical variables.

Methods

A total of 431 participants were surveyed individually at the Shinchon Severance Hospital, Seoul, Korea, to determine their PA levels before diagnosis, during treatment and after completion of cancer treatment.

Results

Percentage of survivors meeting American College of Sports Medicine guideline significantly reduced from 27 % before diagnosis to 10 % during treatment due to reduced strenuous intensity PA (28.8?±?106.2 vs 11.8?±?95.9 min, p?=?0.042), while total PA and mild intensity PA did not change. Total (187.2?±?257.7 vs. 282.6?±?282.0 min, p?<?0.001) and mild (99.1?±?191.5 vs. 175.1?±?231.2 min, p?<?0.001) intensity PA significantly increased after the completion of treatments compared with their PA level before diagnosis. Further analyses showed that age (more vs. equal or less than 60 years) and chemotherapy (chemotherapy vs. no chemotherapy) significantly influenced the level of physical activity (p?=?0.004). Survivors who were older or received chemotherapy increased their total PA and mild intensity PA after the completion of treatment more than those who did not receive chemotherapy.

Conclusions

The level and the pattern of physical activity by colorectal cancer survivors differed across cancer trajectories, which were significantly influenced by age and adjuvant chemotherapy.     

Pilot Study of a Novel 18F-labeled FSHR Probe for Tumor Imaging

Purpose

Follicle-stimulating hormone receptor (FSHR) is overexpressed in primary and metastatic tumor. Molecular imaging of FSHR is beneficial for prognosis and therapy of cancer. FSHβ(33–53) (YTRDLVYKDPARPKIQKTCTF), denoted as FSH1, is a FSHR antagonist. In the present study, maleimide-NOTA conjugate of FSH1 (NOTA-MAL-FSH1) was designed and labeled with [¹⁸F] aluminum fluoride. The resulting tracer, ¹⁸F-Al-NOTA-MAL-FSH1, was preliminarily evaluated in PET imaging of FSHR-positive tumor.

Procedures

NOTA-MAL-FSH1 was synthesized and radiolabeled with Al¹⁸F complex. The tumor-targeting potential and pharmacokinetic profile of the ¹⁸F-labeled compound were evaluated in vitro and in vivo using a PC3 human prostate tumor model.

Results

¹⁸F-Al-NOTA-MAL-FSH1 can be efficiently produced within 30 min with a non-decay-corrected yield of 48.6?±?2.1 % and a radiochemical purity of more than 95 %. The specific activity was at least 30 GBq/μmol. The radiotracer was stable in phosphate-buffered saline and human serum for at least 2 h. The IC₅₀ values of displacement ¹⁸F-Al-NOTA-MAL-FSH1 with FSH1 were 252?±?1.12 nM. The PC3 human prostate tumor xenografts were clearly visible with high contrast after injection of ¹⁸F-Al-NOTA-MAL-FSH1 via microPET. At 30, 60 and 120 min postinjection, the tumor uptakes were 2.98?±?0.29 % injected dose (ID)/g, 2.53?±?0.20 %ID/g and 1.36?±?0.12 %ID/g, respectively. Dynamic PET scanning showed that tumor uptake reached a plateau by about 6 min. Heart peaked earlier and then cleared quickly. Biodistribution studies confirmed that the normal organs except kidney uptakes were all below 1 %ID/g at 1 h p.i. The tumor-to-blood and tumor-to-muscle ratio at 10 min, 0.5, 1, and 2 h after injection were 1.64?±?0.36, 2.97?±?0.40, 9.31?±?1.06, and 13.59?±?2.33 and 7.05?±?1.10, 10.10?±?1.48, 16.17?±?3.29, and 30.88?±?4.67, respectively. The tracer was excreted mainly through the renal system, as evidenced by high levels of radioactivity in the kidneys. FSHR-binding specificity was also demonstrated by reduced tumor uptake of ¹⁸F-Al-NOTA-MAL-FSH1 after coinjection with an excess of unlabeled FSH1 peptide.

Conclusion

NOTA-MAL-FSH1 could be labeled rapidly and efficiently with ¹⁸F using one step method. Favorable preclinical data suggest that ¹⁸F-Al-NOTA-MAL-FSH1 may be a suitable radiotracer for the non-invasive visualization of FSHR positive tumor in vivo.     

ECMO criteria for influenza A (H1N1)-associated ARDS: role of transpulmonary pressure

Purpose

To assess whether partitioning the elastance of the respiratory system (E _RS) between lung (E _L) and chest wall (E _CW) elastance in order to target values of end-inspiratory transpulmonary pressure (PPLAT_L) close to its upper physiological limit (25?cmH₂O) may optimize oxygenation allowing conventional treatment in patients with influenza A (H1N1)-associated ARDS referred for extracorporeal membrane oxygenation (ECMO).

Methods

Prospective data collection of patients with influenza A (H1N1)-associated ARDS referred for ECMO (October 2009?CJanuary 2010). Esophageal pressure was used to (a) partition respiratory mechanics between lung and chest wall, (b) titrate positive end-expiratory pressure (PEEP) to target the upper physiological limit of PPLAT_L (25?cmH₂O).

Results

Fourteen patients were referred for ECMO. In seven patients PPLAT_L was 27.2?±?1.2?cmH₂O; all these patients underwent ECMO. In the other seven patients, PPLAT_L was 16.6?±?2.9?cmH₂O. Raising PEEP (from 17.9?±?1.2 to 22.3?±?1.4?cmH₂O, P?=?0.0001) to approach the upper physiological limit of transpulmonary pressure (PPLAT_L?=?25.3?±?1.7?cm H₂O) improved oxygenation index (from 37.4?±?3.7 to 16.5?±?1.4, P?=?0.0001) allowing patients to be treated with conventional ventilation.

Conclusions

Abnormalities of chest wall mechanics may be present in some patients with influenza A (H1N1)-associated ARDS. These abnormalities may not be inferred from measurements of end-inspiratory plateau pressure of the respiratory system (PPLAT_RS). In these patients, titrating PEEP to PPLAT_RS may overestimate the incidence of hypoxemia refractory to conventional ventilation leading to inappropriate use of ECMO.     

A treatment protocol including vasopressin and hydroxyethyl starch solution is associated with increased rate of return of spontaneous circulation in blunt trauma patients with pulseless electrical activity

Background

Survival after cardiopulmonary resuscitation (CPR) using standard vasopressor therapy is disappointing. Vasopressin is a potent vasopressor that could become a useful therapeutic alternative in the treatment of cardiac arrest.

Aims

The aim of this prehospital prospective cohort study was to assess the influence of treatment with vasopressin and hydroxyethyl starch solution (HHS) on outcome in resuscitated blunt trauma patients with pulseless electrical activity (PEA) cardiac arrest.

Methods

Two treatment groups of resuscitated trauma patients in cardiac arrest were compared: in the epinephrine group patients received epinephrine 1 mg IV every 3 min only; in the vasopressin group patients first received hypertonic HHS and arginine vasopressin 40 units IV only or followed by epinephrine 1 mg every 3 min until cessation of CPR. Medical trauma care was provided according to advanced trauma life support (ATLS) guidelines.

Results

The study included 31 patients and there were no significant demographic or clinical differences between the treatment groups. Significantly more circulatory restorations [11/13 (85%) vs 3/18 (17%); P?P?=?0.001] were observed in the vasopressin group. Average mean arterial pressure (100.4?±?11.4 mmHg vs 80.3?±?12.4 mmHg) and final end-tidal partial pressure of carbon dioxide (PETCO₂) at admission (4.5?±?0.9 kPa vs 2.8?±?0.4 kPa) were also higher in the vasopressin group.

Conclusion

Our results suggest that victims of severe blunt trauma with PEA should be initially treated with vasopressin in combination with HHS volume resuscitation followed by standard resuscitation therapy and other procedures when appropriate. Vasopressin might be potentially lifesaving in blunt trauma cardiac arrest compared to standard treatment with epinephrine.     

A High-Affinity Near-Infrared Fluorescent Probe to Target Bombesin Receptors

Purpose

This study aimed to create new optical surgical navigation NIRF probes for prostate and breast cancers.

Procedures

IR800-linker-QWAVGHLM-NH₂ with linker = GSG, GGG, and G-Abz4 were synthesized and characterized. IC₅₀ for bombesin receptors (BBN-R) in PC-3 prostate and T47D breast cancer cells, fluorescence microscopy in PC-3 cells, and NIRF imaging in mice PC-3 tumor xenografts were studied.

Results

GGG, GSG, and G-Abz4 derivatives had IC₅₀ (nM) for BBN-R+ PC-3 cells?=?187?±?31, 56?±?5, and 2.6?±?0.2 and T47D cells?=?383?±?1, 57.4?±?1.2, and 3.1?±?1.1, respectively. By microscopy the Abz4 derivative showed the highest uptake, was competed with by BBN, and had little to no binding to BBN-R? cells. In NIRF imaging the G-Abz4 probe was brighter than GGG probe in BBN-R+ tissues in vivo and tissues, tumors, and tumor slices ex vivo. Uptake could be partially blocked in BBN-R+ pancreas but not visibly in tumor.

Conclusions

Linker choice can dominate peptidic BBN-R binding. The G-Abz4 linker yields a higher affinity and specific BBN-R binder in this series of molecules.     

[68Ga]-Albumin-PET in the Monitoring of Left Ventricular Function in Murine Models of Ischemic and Dilated Cardiomyopathy: Comparison with Cardiac MRI

Purpose

The purpose of this study is to evaluate left ventricular functional parameters in healthy mice and in different murine models of cardiomyopathy with the novel blood pool (BP) positron emission tomography (PET) tracer [⁶⁸Ga]-albumin.

Procedures

ECG-gated microPET examinations were obtained in healthy mice, and mice with dilative (DCM) and ischemic cardiomyopathy (ICM) using the novel BP tracer [⁶⁸Ga]-albumin (Alb_BP), as well as [¹⁸F]-FDG microPET. Cine-magnetic resonance imaging (MRI) examination performed on a clinical 1.5-T MRI provided the reference standard measurements.

Results

When considering the combined group of healthy controls, DCM and ICM Alb_BP-PET significantly overestimated the magnitudes of EDV (Alb_BP, 181?±?86 μl; cine-MRI, 125?±?80 μl; P?<?0.001) and ESV (Alb_BP, 136?±?92 μl; cine-MRI, 96?±?77 μl; P?<?0.001), whereas the EF (Alb_BP, 31?±?16 %; cine-MRI, 33?±?21 %; P?=?0.910) matched closely to cine-MRI results, as did findings with [¹⁸F]-FDG. High correlations were found between the measured cardiac parameters (EDV: R?=?0.978, ESV: R?=?0.989, and LVEF: R?=?0.992).

Conclusions

Measuring left ventricular function in mice with [⁶⁸Ga]-albumin BP PET is feasible and showed a high correlation compared to cine-MRI, which was used as a reference standard.     

Lower tidal volume strategy (≈3 ml/kg) combined with extracorporeal CO2 removal versus ‘conventional’ protective ventilation (6 ml/kg) in severe ARDS

Background

Acute respiratory distress syndrome is characterized by damage to the lung caused by various insults, including ventilation itself, and tidal hyperinflation can lead to ventilator induced lung injury (VILI). We investigated the effects of a low tidal volume (V _T) strategy (V _T ≈ 3 ml/kg/predicted body weight [PBW]) using pumpless extracorporeal lung assist in established ARDS.

Methods

Seventy-nine patients were enrolled after a ‘stabilization period’ (24 h with optimized therapy and high PEEP). They were randomly assigned to receive a low V _T ventilation (≈3 ml/kg) combined with extracorporeal CO₂ elimination, or to a ARDSNet strategy (≈6 ml/kg) without the extracorporeal device. The primary outcome was the 28-days and 60-days ventilator-free days (VFD). Secondary outcome parameters were respiratory mechanics, gas exchange, analgesic/sedation use, complications and hospital mortality.

Results

Ventilation with very low V _T’s was easy to implement with extracorporeal CO₂-removal. VFD’s within 60 days were not different between the study group (33.2 ± 20) and the control group (29.2 ± 21, p = 0.469), but in more hypoxemic patients (PaO₂/FIO₂ ≤150) a post hoc analysis demonstrated significant improved VFD-60 in study patients (40.9 ± 12.8) compared to control (28.2 ± 16.4, p = 0.033). The mortality rate was low (16.5 %) and did not differ between groups.

Conclusions

The use of very low V _T combined with extracorporeal CO₂ removal has the potential to further reduce VILI compared with a ‘normal’ lung protective management. Whether this strategy will improve survival in ARDS patients remains to be determined (Clinical trials NCT 00538928).     

The impact of bone mineral density testing,fracture assessment,and osteoporosis education in men treated by androgen deprivation for prostate cancer: a pilot study

Purpose

Men receiving androgen deprivation therapy for prostate cancer have low knowledge of osteoporosis (OP) and engage in few healthy bone behaviors (HBBs). A multicomponent intervention was piloted in this population. Changes in OP knowledge, self-efficacy, health beliefs, and engagement in HBBs were evaluated.

Methods

A pre-post pilot study was performed in a convenience sample of men recruited from the Princess Margaret Cancer Centre. Men were sent personalized letters explaining their dual x-ray absorptiometry (DXA) results and fracture risk assessment with an OP-related education booklet. Participants completed questionnaires assessing OP knowledge, self-efficacy, health beliefs, and current engagement in HBBs at baseline (T1) and 3 months post-intervention (T2). Paired t tests and McNemar’s test were used to assess changes in outcomes.

Results

A total of 148 men completed the study. There was an increase in OP knowledge (9.7?±?4.3 to 11.4?±?3.3, p?<?0.0001) and feelings of susceptibility (16.5?±?4.3 to 17.4?±?4.7, p?=?0.015), but a decrease in total self-efficacy (86.3?±?22.9 to 81.0?±?27.6, p?=?0.007) from baseline to post-intervention. Men made appropriate changes in their overall daily calcium intake (p?≤?0.001), and there was uptake of vitamin D supplementation from 44 % (n?=?65) to 68 % (n?=?99) (p?<?0.0001). Men with bone loss (osteopenia or OP) had a greater change in susceptibility (1.9?±?4.3 vs. ?0.22?±?4.2, p?=?0.005) compared to men with normal bone density.

Conclusions

Our results provide preliminary evidence that a multicomponent intervention such as the one described can lead to increased knowledge and feelings of susceptibility regarding OP and can enhance uptake of some HBBs.     

The ALIEN study: incidence and outcome of acute respiratory distress syndrome in the era of lung protective ventilation

Purpose

While our understanding of the pathogenesis and management of acute respiratory distress syndrome (ARDS) has improved over the past decade, estimates of its incidence have been controversial. The goal of this study was to examine ARDS incidence and outcome under current lung protective ventilatory support practices before and after the diagnosis of ARDS.

Methods

This was a 1-year prospective, multicenter, observational study in 13 geographical areas of Spain (serving a population of 3.55 million at least 18?years of age) between November 2008 and October 2009. Subjects comprised all consecutive patients meeting American-European Consensus Criteria for ARDS. Data on ventilatory management, gas exchange, hemodynamics, and organ dysfunction were collected.

Results

A total of 255 mechanically ventilated patients fulfilled the ARDS definition, representing an incidence of 7.2/100,000?population/year. Pneumonia and sepsis were the most common causes of ARDS. At the time of meeting ARDS criteria, mean PaO₂/FiO₂ was 114?±?40?mmHg, mean tidal volume was 7.2?±?1.1?ml/kg predicted body weight, mean plateau pressure was 26?±?5?cmH₂O, and mean positive end-expiratory pressure (PEEP) was 9.3?±?2.4?cmH₂O. Overall ARDS intensive care unit (ICU) and hospital mortality was 42.7% (95%CI 37.7?C47.8) and 47.8% (95%CI 42.8?C53.0), respectively.

Conclusions

This is the first study to prospectively estimate the ARDS incidence during the routine application of lung protective ventilation. Our findings support previous estimates in Europe and are an order of magnitude lower than those reported in the USA and Australia. Despite use of lung protective ventilation, overall ICU and hospital mortality of ARDS patients is still higher than 40%.     

TEG® and RapidTEG® are unreliable for detecting warfarin-coagulopathy: a prospective cohort study

Background

Thromboelastography^® (TEG) utilizes kaolin, an intrinsic pathway activator, to assess clotting function. Recent published studies suggest that TEG results are commonly normal in patients receiving warfarin, despite an increased International Normalized Ratio (INR). Because RapidTEG? includes tissue factor, an extrinsic pathway activator, as well as kaolin, we hypothesized that RapidTEG would be more sensitive in detecting a warfarin-effect.

Methods

Included in this prospective study were 22 consecutive patients undergoing elective cardioversion and receiving warfarin. Prior to cardioversion, blood was collected to assess INR, Prothrombin Time, TEG, and RapidTEG.

Results

INR Results: 2.8?±?0.5 (1.6 to 4.2). Prothrombin Time Results: 19.1?±?2.2 (13.9. to 24.3). TEG Results (Reference Range): R-Time: 8.3?±?2.7 (2–8); K-Time: 2.1?±?1.4 (1–3); Angle: 62.5?±?10.3 (55–78); MA: 63.2?±?10.3 (51–69); G: 9.4?±?3.5 (4.6-10.9); R-Time within normal range: 10 (45.5%) with INR 2.9?±?0.3; Correlation coefficients for INR and each of the 5 TEG variables were insignificant (P?>?0.05). RapidTEG Results (Reference Range): ACT: 132?±?58 (86–118); K-Time: 1.2?±?0.5 (1–2); Angle: 75.4?±?5.2 (64–80); MA: 63.4?±?5.1 (52–71); G: 8.9?±?2.0 (5.0-11.6); ACT within normal range: 9 (40.9%) with INR 2.7?±?0.5; Correlation coefficients for INR and each of the 5 RapidTEG variables were insignificant (P?>?0.05).

Conclusions

TEG, using kaolin activation, and RapidTEG, with kaolin and tissue factor activation, were normal in a substantial percent of warfarin patients, despite an increased INR. The false-negative rate for detecting warfarin coagulopathy with either test is unacceptable. The lack of correlation between INR and all TEG and RapidTEG components further indicates that these methodologies are insensitive to warfarin effects. Findings suggest that intrinsic pathway activation may mitigate detection of an extrinsic pathway coagulopathy.     

Chest compressions versus ventilation plus chest compressions in a pediatric asphyxial cardiac arrest animal model

Objective

To compare the ventilation achieved with chest compressions (CC) or ventilation plus compressions (VC) in a pediatric animal model of cardiac arrest.

Design

Randomized experimental study.

Setting

Experimental department of a University Hospital.

Methods

Twelve infant pigs with asphyxial cardiac arrest. Sequential 3-min periods of VC and CC were performed for a total duration of 9 min. Tidal volume (TV), end-tidal CO₂ (EtCO₂), mean arterial pressure (MAP), central venous pressure (CVP), mean pulmonary arterial pressure (mPAP), and peripheral, cerebral, and renal saturations were recorded and arterial and venous blood gases were analyzed.

Results

VC achieved a TV similar to the preset parameters on the ventilator, whilst the TV in CC was very low (P < 0.001). EtCO₂ with VC was significantly higher than with CC (14.0 vs. 3.9 mmHg, P < 0.05). Arterial pH was higher with VC than with CC (6.99 vs. 6.90 mmHg, P < 0.05). Arterial PCO₂ was lower with VC than with CC (62.1 vs. 97.0 mmHg, P < 0.05). There were no significant differences in the MAP; CVP; mPAP; peripheral, renal, and cerebral saturations; or lactate concentrations between the two techniques.

Conclusions

VC achieves better ventilation than CC during cardiopulmonary resuscitation and has no negative effect on the hemodynamic situation.