Steroids Improve Hemodynamics in Infants With Adrenal Insufficiency After Cardiac Surgery.

OBJECTIVE: To investigate whether steroid replacement therapy improved hemodynamics in infants after surgery for congenital heart disease only when they develop adrenal insufficiency. The authors retrospectively investigated adrenal function and evaluated hemodynamic responses to steroid replacement therapy in infants after surgery for congenital heart disease. DESIGN: Retrospective, cohort study. SETTING: Intensive care unit in the National Cerebral and Cardiovascular Center Hospital in Japan. PATIENTS: Thirty-two neonates and infants<3 months old who underwent cardiovascular surgery. INTERVENTIONS: The patients were divided into 2 groups based on corticotropin stimulation test results: group AI with adrenal insufficiency (baseline cortisol<15 µg/dL or incremental increase after testing of<9 µg/dL, with baseline cortisol of 15-34 µg/dL); and group N with normal adrenal function. The corticotropin stimulation test was performed by injecting 3.5 µg/kg of tetracosactide acetate. Hydrocortisone (1 mg/kg) was administered every 6 hours, and hemodynamics were compared before and after steroid administration between the groups. MEASUREMENTS AND MAIN RESULTS: Seven patients were classified into group AI, and demonstrated a mean blood pressure increase from 53±8 mmHg before treatment to 68±9 mmHg 18 hours after steroid administration (p<0.01). Urine output also increased, from 2.7±1.0 mL/kg/h to 4.8±1.9 mL/kg/h (p<0.05). In group N, neither mean blood pressure nor urine output increased after steroid administration. CONCLUSIONS: After surgery for congenital heart disease, one-fifth of infants developed adrenal insufficiency. Steroid replacement therapy improved hemodynamics only in the subgroup with adrenal insufficiency.

Sodium-glucose Co-transporter 2 Inhibitors Reduce the Abdominal Visceral Fat Area and May Influence the Renal Function in Patients with Type 2 Diabetes.

Objective and Methods An SGLT2 inhibitor (ipragliflozin, dapagliflozin, luseogliflozin, tofogliflozin, or canagliflozin) was administered to 132 outpatients with type 2 diabetes mellitus with or without other antidiabetic drugs for 6 months to evaluate its efficacy, the incidence of adverse events, and its influence on the renal function. Results The patient's mean glycated hemoglobin level significantly improved from 7.52±1.16% to 6.95±0.98% (p<0.001). The body weight of the patients was significantly reduced from 78.0±15.3 kg to 75.6±15.1 kg (p<0.001). The estimated visceral fat area was also significantly reduced from 108.4±44.6 cm2 to 94.5±45.3 cm2 (p<0.001). The waist circumference, blood pressure, serum alanine aminotransferase, γ-glutamyl transpeptidase, and uric acid levels also showed a significant decrease. The urinary albumin/creatinine ratio (U-ACR) was significantly reduced in the patients whose U-ACR levels were 30-300 mg/gCr at the baseline. The mean eGFR significantly decreased in the patients with a pre-treatment eGFR value of ≥90 mL/min/1.73 m2 but remained unchanged in the patients with a pre-treatment value of <90 mL/min/1.73 m2. A total of 13 adverse events were noted, including systemic eruption (n=1), cystitis (n=2), pudendal pruritus (n=2), nausea (n=1), malaise (n=1), a strong hunger sensation and increased food ingestion (n=1), and non-serious hypoglycemia (n=5). Conclusion SGLT2 inhibitors seemed to be useful in the treatment of obese type 2 diabetes mellitus patients. Furthermore, these data suggest that SGLT2 inhibitors may protect the renal function.

The impact of endotracheal suctioning on gas exchange and hemodynamics during lung-protective ventilation in acute respiratory distress syndrome.

OBJECTIVE: To evaluate the respiratory and hemodynamic effects of open suctioning (OS) versus closed suctioning (CS) during pressure-control (PC) and volume-control (VC) ventilation, using a lung-protective ventilation strategy in an animal model of acute respiratory distress syndrome (ARDS). SETTING: Animal laboratory in a university hospital. DESIGN: Randomized cross-over evaluation. ANIMALS: Eight female Dorset sheep. INTERVENTIONS: Lung lavage was used to simulate ARDS. We applied VC and PC mechanical ventilation with a tidal volume of 6 mL/kg and positive end-expiratory pressure (PEEP), adjusted based on a table of PEEP versus fraction of inspired oxygen (FIO2). Suctioning was performed for 10 s with a suction pressure of -100 mm Hg, during both OS and CS. OS and CS were randomly performed with each animal. Hemodynamics and arterial blood gases were recorded before, during, and after endotracheal suctioning. RESULTS: The PaO2/FIO2 ratios before suctioning were similar in all groups, as were the PEEP and FIO2. PaO2/FIO2 was lower after OS than after CS/VC or CS/PC. There was no post-suctioning difference in oxygenation between CS/VC and CS/PC. PaCO2 recorded 10 min after suctioning was greater than the presuctioning value, in all groups. Intrapulmonary shunt fraction increased between baseline and 10 min post-suctioning with OS and CS/VC, but did not significantly increase with CS/PC. There were no significant changes in hemodynamics pre-suctioning versus post-suctioning with OS, CS/VC, or CS/PC. CONCLUSION: PaO2/FIO2) was better maintained during CS with both VC and PC modes during lung-protective ventilation for ARDS, as compared with OS, and shunt fraction post-suctioning changed least with PC.

Effects of reduced rebreathing time, in spontaneously breathing patients, on respiratory effort and accuracy in cardiac output measurement when using a partial carbon dioxide rebreathing technique: a prospective observational study.

INTRODUCTION: New technology using partial carbon dioxide rebreathing has been developed to measure cardiac output. Because rebreathing increases respiratory effort, we investigated whether a newly developed system with 35 s rebreathing causes a lesser increase in respiratory effort under partial ventilatory support than does the conventional system with 50 s rebreathing. We also investigated whether the shorter rebreathing period affects the accuracy of cardiac output measurement. METHOD: Once a total of 13 consecutive post-cardiac-surgery patients had recovered spontaneous breathing under pressure support ventilation, we applied a partial carbon dioxide rebreathing technique with rebreathing of 35 s and 50 s in a random order. We measured minute ventilation, and arterial and mixed venous carbon dioxide tension at the end of the normal breathing period and at the end of the rebreathing periods. We then measured cardiac output using the partial carbon dioxide rebreathing technique with the two rebreathing periods and using thermodilution. RESULTS: With both rebreathing systems, minute ventilation increased during rebreathing, as did arterial and mixed venous carbon dioxide tensions. The increases in minute ventilation and arterial carbon dioxide tension were less with 35 s rebreathing than with 50 s rebreathing. The cardiac output measures with both systems correlated acceptably with values obtained with thermodilution. CONCLUSION: When patients breathe spontaneously the partial carbon dioxide rebreathing technique increases minute ventilation and arterial carbon dioxide tension, but the effect is less with a shorter rebreathing period. The 35 s rebreathing period yielded cardiac output measurements similar in accuracy to those with 50 s rebreathing.

The effects of dexmedetomidine on the ventilatory response to hypercapnia in rabbits.

OBJECTIVE: Dexmedetomidine is a highly selective alpha(2)-adrenergic agonist that can reduce anesthetic requirements. This study, to assess its effect on respiration, examined the effects of various doses of dexmedetomidine (1, 10, 30 and 50 microg/kg) on the respiratory response to carbon dioxide (CO(2)) breathing in rabbits. DESIGN: Randomized prospective study. SETTING: Animal laboratory at a university school of medicine. INTERVENTION: From 28 animals, four groups of seven were randomly assigned to receive different doses of dexmedetomidine (groups D1, D10, D30 and D50). Under inhalation of sevoflurane, each animal was tracheostomized and intubated with a 4 mm internal diameter (i.d.) endotracheal tube. MEASUREMENTS AND RESULTS: After end-tidal sevoflurane concentration had decreased below 0.03% and during quiet breathing (QB); respiratory rate (RR), tidal volume (V(T)) and inspiratory time (T(I)) were measured, from which minute ventilation (MV) and mean inspiratory flow (V(T)/T(I)) were calculated. After these measurements had been completed, each animal breathed the balloon gas (5% CO(2) and 95% O(2)) until the end-tidal CO(2) (ETCO(2)) reached 10%. The respiratory measurements were repeated during the latter period. After the collection of these data, dexmedetomidine was infused intravenously and the same measurements were repeated 15 and 45 min after dexmedetomidine infusion. The slope of the ventilatory response to hypercapnia in D50 was significantly higher compared with D30 animals. In the range 1-30 microg/kg, during both QB and at 10% ETCO(2), MV was decreased in a dose-dependent manner. Dexmedetomidine depressed both V(T) and RR during QB and at 10% ETCO(2). CONCLUSION: Dexmedetomidine depressed resting ventilation and the respiratory response to CO(2), but it did not induce profound hypoxemia or hypercapnia in rabbits.

Peak volume history and peak pressure-volume curve pressures independently affect the shape of the pressure-volume curve of the respiratory system.

OBJECTIVE: To determine the specific effect of peak volume history pressure on the inflation limb of the pressure-volume curve and peak pressure-volume curve pressure on the deflation limb of the pressure-volume curve. DESIGN: Prospective assessment of pressure-volume curves in saline, lung lavage injured sheep. SETTING: Large animal laboratory of a university-affiliated hospital. SUBJECTS: Eight female Dorset sheep. INTERVENTIONS: : The effect of two volume history pressures (40 and 60 cm H2O) and three pressure-volume curve peak pressures (40, 50, and 60 cm H2O) were randomly compared. MEASUREMENTS AND MAIN RESULTS: Peak volume history pressure affected the inflation curve beyond the lower inflection point but did not affect the inflection point (Pflex). Peak pressure-volume curve pressure affected the deflation curve. Increased peak volume history pressure increased inflation compliance (p <.05). Increased peak pressure-volume curve pressure increased the point of maximum compliance change on the deflation limb and deflation compliance and decreased compliance between peak pressure and the point of maximum curvature on the deflation limb (p <.05). CONCLUSION: Peak volume history pressure must be considered when interpreting the inflation limb of the pressure-volume curve of the respiratory system beyond the inflection point. The peak pressure achieved during the pressure-volume curve is important during interpretation of deflation compliance and the point of maximum compliance change on the deflation limb.