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Biomedical subjects

M Ritz

Publications and source records attributed to M Ritz.

At least 19 recordsLinked to original sources
PubMed2006

Inactivation of Salmonella Typhimurium and Listeria monocytogenes using high-pressure treatments: destruction or sublethal stress?

AIMS: To investigate potential resuscitation of Listeria monocytogenes and Salmonella Typhimurium after high hydrostatic pressure treatments. METHODS AND RESULTS: Pressure treatments were applied at room temperature for 10 min on bacterial suspensions in buffers at pH 7 and 5.6. Total bacterial inactivation (8 log(10) CFU ml(-1) of bacterial reduction) obtained by conventional plating was achieved regarding both micro-organisms. Treatments at 400 MPa in pH 5.6 and 600 MPa in pH 7 for L. monocytogenes and at 350 MPa in pH 5.6 and 400 MPa in pH 7 for S. Typhimurium were required respectively. A 'direct viable count' method detected some viable cells in the apparently totally inactivated population. Resuscitation was observed for the two micro-organisms during storage (at 4 and 20 degrees C) after almost all treatments. In the S. Typhimurium population, 600 MPa, 10 min, was considered as the treatment achieving total destruction because no resuscitation was observed under these storage conditions. CONCLUSIONS: We suggest a delay before performing counts in treated samples in order to avoid the under-evaluation of surviving cells. SIGNIFICANCE AND IMPACT OF THE STUDY: The resuscitation of pathogen bacteria after physical treatments like high hydrostatic pressure has to be considered from the food safety point of view. Further studies should be performed in food products to study this resuscitation phenomenon.

Colony Count, Microbial↗
PubMed2005

Influence of kinetic parameters of high pressure processing on bacterial inactivation in a buffer system.

High pressure processing is recently applied in the food industry to inactivate spoilage and pathogenic microorganisms. Bacterial cells exhibit various barosensibility, and the role of pressurization, depressurization and constant pressure stage remain unknown. We investigated the effect of high pressure processing on Salmonella typhimurium and Listeria monocytogenes cells at 400 and 500 MPa respectively in buffer pH 7 at 20 degrees C. We applied various pressurization/depressurization kinetic rates (1, 5 and 10 MPa/s for pressurization and 250, 20 and 5 MPa/s for depressurization), and various pulse series or pressure holding times. Results show that high pressure pulses reduced linearly the number of bacterial cells according to the product of pressure and time: we defined this product as a Barometric Power (BP). Reduction of both microorganisms increased when holding time increased from 5 to 20 min, and better results were obtained when the rate of pressurization and depressurization were increased.

Colony Count, Microbial↗
PubMed2002

Physiological damages of Listeria monocytogenes treated by high hydrostatic pressure.

High hydrostatic pressure is a new food preservation technology known for its capacity to inactivate spoilage and pathogenic microorganisms. This study investigated the damages inflicted on Listeria monocytogenes cells treated by high pressure for 10 min at 400 MPa in pH 5.6 citrate buffer. Under these conditions, no cell growth occurred after 48 h on plate count agar. Scanning electron microscopy (SEM) revealed that cellular morphology was not really affected. Measuring propidium iodide (PI) staining followed by flow cytometry demonstrated that membrane integrity was damaged in a small part of the population, although the membrane potential evaluated by oxonol fluorescence or measured by analytical methods was reduced from - 86 to - 5 mV. These results for the first time showed that such combined methods as fluorescent dyes monitored by flow cytometry and physiological activity measurements provide valuable indications on cellular viability.

Flow Cytometry↗
PubMed2001

The effect of acute hyperglycaemia on appetite and food intake in Type 1 diabetes mellitus.

AIMS: To determine the effects of acute hyperglycaemia on appetite and food intake in Type 1 diabetes mellitus. METHODS: Two separate studies, each involving eight adults with uncomplicated Type 1 diabetes, were performed: one in the fasted state (A) and the other after a nutrient preload (B). In both studies, perceptions of appetite (hunger and fullness) and food intake at a buffet meal were evaluated during euglycaemia (blood glucose, approximately 6 mmol/l) and hyperglycaemia (blood glucose, approximately 14 mmol/l). Both experiments were randomized and single-blind. In study A, appetite was assessed in the fasted state for 90 min before the buffet meal. In study B, a nutrient 'preload' of Ensure and milk containing 13C-octanoic acid was consumed 90 min before the meal. Gastric emptying of the preload was quantified with a radioisotopic breath test technique. RESULTS: There was no significant difference in plasma insulin concentrations between euglycaemia and hyperglycaemia in either study. In study A, there were no differences in hunger, fullness or energy intake between the two treatment days. In study B, subjects were slightly less hungry between the preload and buffet meal during hyperglycaemia than euglycaemia (P = 0.04), and tended to have slower gastric emptying during hyperglycaemia (emptying coefficient, 3.89 +/- 0.16 vs. 3.57 +/- 0.21; P = 0.052), but there was no difference in food intake between hyperglycaemia and euglycaemia. CONCLUSIONS: Acute hyperglycaemia suppresses hunger after a nutrient preload, but not in the fasted state, in patients with uncomplicated Type 1 diabetes. This effect is small and not associated with changes in food intake.

Adolescent↗
PubMed2001

Morphological and physiological characterization of Listeria monocytogenes subjected to high hydrostatic pressure.

High hydrostatic pressure is a new food preservation technology known for its capacity to inactivate spoilage and pathogenic microorganisms. That inactivation is usually assessed by the number of colonies growing on solid media after treatment. Under normal conditions the method does not permit recovery of damaged cells and may underestimate the number of cells that will remain viable and grow after a few days in high-pressure-processed foodstuffs. This study investigated the damage inflicted on Listeria monocytogenes cells treated by high pressure for 10 min at 400 MPa in pH 5.6 citrate buffer. Under these conditions, no cell growth occurred after 48 h on plate count agar. Scanning electron microscopy, light scattering by flow cytometry, and cell volume measurements were compared to evaluate the morphological changes in cells after pressurization. All these methods revealed that cellular morphology was not really affected. Esterase activity, as assessed either by enzymatic activity assays or by carboxy fluorescein diacetate fluorescence monitored by flow cytometry, was dramatically lowered, but not totally obliterated, under the effects of treatment. The measurement of propidium iodide uptake followed by flow cytometry demonstrated that membrane integrity was preserved in a small part of the population, although the membrane potential measured by analytical methods or evaluated by oxonol uptake was reduced from -86 to -5 mV. These results showed that such combined methods as fluorescent dyes monitored by flow cytometry and physiological activity measurements provide valuable indications of cellular viability.

Colony Count, Microbial↗
PubMed2000

Effects of high hydrostatic pressure on membrane proteins of Salmonella typhimurium.

Salmonella typhimurium is a leading cause of foodborne diseases. Today high hydrostatic pressure treatments are considered as alternative methods of preservation. To select optimal conditions of treatment, we have to characterize the cell targets of pressure. In this study the action of pressure on the bacterial membrane proteins is analysed. The total membrane extract is obtained by lysis of cells separated by equilibrium density gradient centrifugation. Protein content is analysed by electrophoresis SDS-PAGE and visualised by silver stain. Electrophoretic profiles reveal the presence of three major outer membrane proteins and 12 minor proteins in control bacteria outer membranes. Outer membrane protein content is drastically modified after treatments. In some cases, except for the major proteins OmpA and LamB, other outer membrane proteins seem to totally disappear. LamB is more resistant to hyperbaric exposure when the pH of the media is acidic. This behaviour could be explained by a different conformation adopted by the LamB protein depending on the extracellular pH. This work allows us to define membrane proteins as a target of high hydrostatic pressure treatments. Knowledge of the behaviour of these bacterial membrane proteins subjected to pressure under different conditions (pH, temperature, a(w)...) could allow an increase in the efficiency of treatments.

Bacterial Proteins↗
PubMed2000

Physiological effects of high hydrostatic pressure treatments on Listeria monocytogenes and Salmonella typhimurium.

The effect of a high hydrostatic pressure treatment on the Gram-positive Listeria monocytogenes strain Scott A and the Gram-negative Salmonella typhimurium strain Mutton (ATCC13 311) has been determined in stationary phase cell suspensions. Pressure treatments were done at room temperature for 10 min in sodium citrate (pH 5.6) and sodium phosphate (pH 7.0) suspension buffers. Increasing pressure treatments resulted in an exponential decrease of cell counts. Salmonella typhimurium suspended at low pH was more sensitive to pressure treatments. Progressive morphological changes were evident with the pressure increase. Cell lysis only appeared with the highest pressure treatments. Cell volume was not affected by pressure treatment. A progressive decrease of deltapH (pHin - pHout), intracellular potassium and ATP contents was demonstrated with the pressure increase. A parallel lowering of membrane potentials was measured.

Adenosine Triphosphate↗
PubMed2000

Kinetics of photoacclimation in response to a shift to high light of the red alga Rhodella violacea adapted to low irradiance.

The unicellular rhodophyte Rhodella violacea can adapt to a wide range of irradiances. To create a light stress, cells acclimated to low light were transferred to higher irradiance and the kinetics of various changes produced by the light shift were analyzed. The proton gradient generated by excess light led to a non-photochemical quenching of the chlorophyll fluorescence and some photoinhibition of photosystem II centers was also produced by the light stress. After the shift to higher irradiance, the mRNA levels of three chloroplast genes that encode phycoerythrin and phycocyanin apoproteins and heme oxygenase (the first enzyme specific to the bilin synthesis) were negatively regulated. A change in the amount of thylakoids and in the total pigment content of the cells occurred during light acclimation after a light stress. The change in the size of the phycobilisome was limited to dissapearance of the terminal phycoerythrin hexamers in some of the rods. The ability of R. violacea to photoacclimate depends both on large changes in thylakoid number and pigment content and on smaller changes in the antenna size of photosystem II.

Acclimatization↗
PubMed2000

Retroperitoneal mature teratoma 15 years after initial treatment of testicular mixed germ cell tumor.

We present a patient with a retroperitoneal tumor noted 15 years after treatment of a testicular mixed germ cell cancer. The patient initially underwent right-sided orchiectomy and retroperitoneal lymph node dissection for clinical stage I disease. An early relapse indicated by increasing tumor markers shortly after retroperitoneal lymph node dissection was successfully treated with five cycles of combined chemotherapy. However, 187 months after completion of chemotherapy, a symptomatic right-sided iliac mass was diagnosed. Radical surgical excision of the mass was performed and histologic examination revealed differentiated mature teratoma. This represents the longest time interval reported in the literature for a mature teratoma following treatment of a testicular germ cell tumor.

Adult↗
PubMed1999

Effects of spiroglumide, a gastrin receptor antagonist, on acid secretion in humans.

BACKGROUND: A gastrin receptor antagonist, CR2194 (spiroglumide), was used to explore the physiological role of gastrin in regulating gastric acid secretion in humans. MATERIALS AND METHODS: The effect of CR2194 on inhibition of gastrin-stimulated acid output was evaluated in a four-period crossover study. Each subject received intravenous doses of 1, 2.5 or 7.5 mg kg-1 h-1 CR2194 or saline (control) followed by graded increasing doses of gastrin (6.4-800 pmol kg-1 h-1). Secondly, the effect of CR2194 on meal-stimulated intragastric acidity was evaluated by infusing either saline (control) or CR2194 (7.5 mg kg-1 h-1) before and after food ingestion. RESULTS: Acid secretion was dose-dependently inhibited by CR2194. With CR2194, acidity was significantly reduced in the pre-meal and post-prandial period (P < 0.01 and 0.002 respectively), and the integrated gastrin response was augmented to 8.0 +/- 1.4 ng mL-1 240 min compared with 1.5 +/- 0.8 ng mL-1 240 min in the control experiment (P < 0.01). Finally, acid secretion in response to sham feeding was significantly reduced: 15.9 +/- 0.9 mmol 90 min-1 in the control experiment compared with 2.8 +/- 0.9 mmol 90 min-1 during CR2194 infusion (P < 0.05). CONCLUSION: Gastrin receptor blockade with CR2194 alters gastric acid secretion in response to food ingestion or to sham feeding. The results support a physiological role for gastrin in regulating acid secretion in humans.

Adult↗
PubMed1997

Effects of inhaled salmeterol and salbutamol (albuterol) on morning dips compared in intensive care patients recovering from an acute severe asthma attack.

OBJECTIVE: To assess the effect of a long-acting inhaled beta 2-agonist, salmeterol (SM), compared to a short-acting inhaled beta 2-agonist, salbutamol (or albuterol, SB) on the occurrence of morning dip (MD) in patients recovering from an acute severe asthma attack (ASA). DESIGN: Prospective study. SETTING: 18-bed, medical intensive care unit (ICU) in a university hospital. PATIENTS: 19 patients suffering from an ASA. INTERVENTIONS: Serial measurements of the peak expiratory flow rate (PEFR), arterial blood gases, vital capacity and forced expiratory volume in one second (FEV1) were performed from admission. All patients were first treated with i.v. methyl prednisolone and i.v. SB. Once the PEFR was stable and > 35% of predicted value, i.v. SB was stopped while i.v. steroids were maintained, and patients were randomised to either inhaled SB (9 patients, 400 micrograms every 4 h) or inhaled SM (10 patients, 100 micrograms every 12 h). RESULTS: The mean admission PEFR was 26.1 +/- 11.7% of the predicted value and was not different between the two groups. MD was more frequent with SB (6/9 patients) than with SM (4/10). The severity of MD, expressed in l/min fall in PEFR, was higher in SB than in SM (106 +/- 25 vs 55 +/- 37; p < 0.05). DISCUSSION: MD is frequent in ASA. In ASA, SM appears to reduce the frequency and the severity of MD more than SB. The clinical implications of this observation, particularly a lowering of mortality and a shortening of the ICU stay, remain to be investigated.

Acute Disease↗
PubMed1997

Additive beneficial effects of the prone position, nitric oxide, and almitrine bismesylate on gas exchange and oxygen transport in acute respiratory distress syndrome.

OBJECTIVE: To test the hypothesis that prone position ventilation, nitric oxide, and almitrine bismesylate, each acting by a different mechanism to improve arterial oxygenation, could exert additive beneficial effects when used in combination in patients with severe acute respiratory distress syndrome (ARDS). DESIGN: Prospective, nonrandomized, interventional study. SETTING: Medical and surgical intensive care units at a university tertiary care center. PATIENTS: Twelve patients with ARDS and severe hypoxemia, defined as PaO2/FIO2 of < or = 150 and FIO2 of > or = 0.6, with pulmonary artery occlusion pressure of < 18 mm Hg. INTERVENTIONS: Inhaled nitric oxide (20 parts per million for 15 mins) in the supine and prone position, and intravenous almitrine bismesylate while prone (1 mg/kg/hr for 60 mins), alone or combined with nitric oxide. MEASUREMENTS AND MAIN RESULTS: Hemodynamic, blood gas, and gas exchange measurements were performed at sequential time points as follows: a) baseline supine; b) nitric oxide in the supine position; c) after return to baseline supine; d) after 30 mins prone; e) after 120 mins prone; f) nitric oxide while prone; g) after return to baseline prone; h) almitrine bismesylate prone; and i) nitric oxide and almitrine bismesylate combined, for 15 mins prone. Patients were considered responders to the prone position if a gain in PaO2 of > or = 10 torr (> or = 1.3 kPa) or a gain in the PaO2/FIO2 ratio of > or = 20 was observed. Seven patients (58%) responded to being turned prone. Compared with supine baseline conditions, nitric oxide and supine position increased arterial oxygen saturation from 89 +/- 1 (SD)% to 92 +/- 3% (p < .05) and nitric oxide plus prone position increased arterial oxygen saturation (94 +/- 3% vs. 89 +/- 4%, p < .05) and decreased the alveolar-arterial oxygen difference from 406 +/- 124 torr (54 +/- 15 kPa) to 387 +/- 108 torr (51 +/- 14 kPa) (p < .05). Almitrine bismesylate increased PaO2/FIO2 vs. baseline (122 +/- 58 vs. 84 +/- 21, p < .05). Almitrine bismesylate decreased the alveolar-arterial oxygen difference vs. baseline from 406 +/- 124 torr (53.9 +/- 16.5 kPa) to 386 +/- 112 torr (51.3 +/- 14.8 kPa) and vs. nitric oxide and supine position from 406 +/- 111 torr (53.9 +/- 14.7 kPa) to 386 +/- 112 torr (51.3 +/- 14.8 kPa) (p < .05). Prone position alone did not improve oxygenation. However, the combination of nitric oxide and almitrine bismesylate increased PaO2/FIO2 vs. nitric oxide supine and nitric oxide prone conditions (147 +/- 69 vs. 84 +/- 25 and 91 +/- 18, respectively; p < .05). In patients responding to the prone position (n = 7), combining nitric oxide and almitrine bismesylate led to further improvement in PaO2 compared with the prone position alone, with PaO2 increasing from 78 +/- 12 torr (10.3 +/- 1.6 kPa) to 111 +/- 55 torr (14.7 +/- 7.3 kPa) (p < .05), which was not the case when either nitric oxide or almitrine bismesylate was added separately. Heart rate and cardiac output were increased by almitrine bismesylate compared with all other measurements. Mean pulmonary arterial pressure was decreased by nitric oxide (27 +/- 7 vs. 30 +/- 7 mm Hg nitric oxide supine vs. baseline supine and 29 +/- 7 vs. 33 +/- 8 mm Hg nitric oxide prone vs. baseline prone, p < .05) and increased by almitrine bismesylate (36 +/- 9 vs. 30 +/- 7 mm Hg baseline supine, 27 +/- 7 mm Hg nitric oxide supine, 33 +/- 8 mm Hg baseline prone, and 29 +/- 7 mm Hg nitric oxide prone; p < .05). The increase in mean pulmonary arterial pressure was totally abolished by nitric oxide (31 +/- 5 vs. 36 +/- 9 mm Hg, p < .05). Minute ventilation, respiratory system compliance, physiologic deadspace, and PaCO2 remained unchanged. CONCLUSION: In ARDS patients with severe hypoxemia, arterial oxygenation can be improved by combining the prone position, nitric oxide, and almitrine bismesylate, without deleterious effects.

APACHE↗
PubMed1997

Nitric oxide and prostacyclin as test agents of vasoreactivity in severe precapillary pulmonary hypertension: predictive ability and consequences on haemodynamics and gas exchange.

BACKGROUND: In patients with primary pulmonary hypertension who respond to vasodilators acutely, survival can be improved by the long term use of calcium channel blockers. However, testing for such a response with calcium channel blockers or prostacyclin (PGI2) may cause hypotension and adversely affect gas exchange. Nitric oxide (NO), which does not have these effects, could be a better test agent. METHODS: NO (10, 20, and 40 ppm for 15 minutes), PGI2 (1-->10 ng/kg/min), and oral nifedipine (10 mg, then 20 mg/h) were administered sequentially to 10 patients after determination of the 24 hour spontaneous variability of their pulmonary and systemic mean arterial pressures. Patients were considered responders if the mean pulmonary artery pressure or pulmonary vascular resistance decreased by 20% or more. RESULTS: Six patients (60%) responded to all three agents, and three to none of the agents. One patient responded to PGI2 only. In those who responded to vasodilators, NO had no major effect on gas exchange or systemic haemodynamics, while PGI2 and nifedipine both induced systemic hypotension (mean (SD) systemic arterial pressure 72 (14) versus 89 (19) mm Hg with PGI2 and 72 (15) versus 86 (17) mm Hg with nifedipine, p < 0.05) and hypoxaemia (PaO2 8.7 (1.4) versus 10.8 (1.0) kPa with PGI2 and 8.6 (1.4) versus 10.2 (1.5) kPa with nifedipine, p < 0.05) and increased venous admixture (28 (9) versus 14 (4)% with PGI2 and 22 (9) versus 13 (5)% with nifedipine, p < 0.05). CONCLUSIONS: NO inhalation can accurately predict a vasodilator response to nifedipine in patients with severe pulmonary hypertension without adverse effects on systemic haemodynamics and gas exchange. This absence of side effects may make it a more appropriate agent for testing the vasodilator response.

Antihypertensive Agents↗
PubMed1997

Haemodynamic and endocrinological effects of noninvasive mechanical ventilation in respiratory failure.

The aim of this study was to investigate the haemodynamic and endocrinological effects of noninvasive positive pressure ventilation (NIPPV). Eleven patients with oedema and recent hypercapnic and hypoxaemic worsening of a chronic respiratory insufficiency were included. Echocardiography, cardiac radionuclide assessment, blood catecholamines, salt and water handling hormones were measured at admission and discharge (long study (LS)). To discriminate between the action of NIPPV and other treatments, measurements were performed on the fourth day, for 4 h without NIPPV and 4 h with NIPPV (short study (SS)). NIPPV entailed a correction of P(a,CO2) and an increase of P(a,O2) in LS and SS. Oedema disappeared. Body weight decreased (from 85+/-42 to 81+/-40 kg) during LS. Systolic and mean pulmonary arterial pressure decreased in LS and SS. Right ventricular ejection fraction increased in LS. Left ventricular ejection fraction did not change. Cardiac index was normal on admission and then decreased. Natriuretic peptides and catecholamines were increased on admission, whereas plasma renin activity, aldosterone and vasopressin were normal. We suggest that in these patients, oedema can occur independently of renin-angiotensin-aldosterone-vasopressin and with a normal cardiac output. Noninvasive positive pressure ventilation allowed a correction of blood gases, associated with the resolution of oedema, a decrease in pulmonary arterial pressures and an increase in right ventricular ejection fraction.

Atrial Natriuretic Factor↗
PubMed1997

Wound modulation via sclerotherapy and tissue adhesion. Observations and discussion.

Fluid accumulation in a 'dead space' after surgery or trauma predisposes the area involved to delayed healing. The fluid may promote inflammatory mediators and other wound-modulating factors, which encourages the continued existence of the dead space. Tissue adhesion by means of agents such as tetracyclines has long been described. With this concept, tissue adhesion has been accomplished with varying success in diverse clinical situations involving non-healing wounds and prophylactically in seroma-prone areas. A total of 69 patients were treated and monitored. The most impressive response to tetracycline tissue adhesion in this study was seen in intra-oral sites, with rapid closure of wounds. More complex wounds such as orocutaneous fistulas or wounds of a more chronic nature such as pressure sores did respond but took longer to resolve. The lateral thigh was found to be the most difficult and unresponsive area to treat (particularly after delayed presentation). Successful prophylactic use of tetracycline in seroma-prone areas (latissimus dorsi/parascapular flaps, etc.) is also described.

Anti-Bacterial Agents↗
PubMed1996

Effects of rapid permissive hypercapnia on hemodynamics, gas exchange, and oxygen transport and consumption during mechanical ventilation for the acute respiratory distress syndrome.

OBJECTIVE: To measure the effects of rapid permissive hypercapnia on hemodynamics and gas exchange in patients with acute respiratory distress syndrome (ARDS). DESIGN: Prospective study. SETTING: 18-bed, medical intensive care unit, university hospital. PATIENTS: 11 mechanically ventilated ARDS patients. INTERVENTION: Patients were sedated and ventilated in the controlled mode. Hypercapnia was induced over a 30-60 min period by decreasing tidal volume until pH decreased to 7.2 and/or P50 increased by 7.5 mmHg. Settings were then maintained for 2 h. RESULTS: Minute ventilation was reduced from 13.5 +/- 6.1 to 8.2 +/- 4.1 l/min (mean +/- SD), PaCO2 increased (40.3 +/- 6.6 to 59.3 +/- 7.2 mmHg), pH decreased (7.40 +/- 0.05 to 7.26 +/- 0.05), and P50 increased (26.3 +/- 2.02 to 31.1 +/- 2.2 mmHg) (p < 0.05). Systemic vascular resistance decreased (865 +/- 454 to 648 +/- 265 dyne.s.cm-5, and cardiac index (CI) increased (4 +/- 2.4 to 4.7 +/- 2.4 l/min/m2) (p < 0.05). Mean systemic arterial pressure was unchanged. Pulmonary vascular resistance was unmodified, and mean pulmonary artery pressure (MPAP) increased (29 +/- 5 to 32 +/- 6 mmHg, p < 0.05). PaO2 remained unchanged, while saturation decreased (93 +/- 3 to 90 +/- 3%, p < 0.05), requiring an increase in FIO2 from 0.56 to 0.64 in order to maintain an SaO2 > 90%. PvO2 increased (36.5 +/- 5.7 to 43.2 +/- 6.1 mmHg, p < 0.05), while saturation was unmodified. The arteriovenous O2 content difference was unaltered. Oxygen transport (DO2) increased (545 +/- 240 to 621 +/- 274 ml/min/m2, p < 0.05), while the O2 consumption and extraction ratio did not change significantly. Venous admixture (Qva/Qt) increased (26.3 +/- 12.3 to 32.8 +/- 13.2, p < 0.05). CONCLUSIONS: These data indicate that acute hypercapnia increases DO2 and O2 off-loading capacity in ARDS patients with normal plasma lactate, without increasing O2 extraction. Whether this would be beneficial in patients with elevated lactate levels, indicating tissue hypoxia, remains to be determined. Furthermore, even though hypercapnia was well tolerated, the increase in Qva/Qt, CI, and MPAP should prompt caution in patients with severe hypoxemia, as well as in those with depressed cardiac function and/or severe pulmonary hypertension.

Adult↗