Biomedical subjects

Glenn Hernandez

Publications and source records attributed to Glenn Hernandez.

4 recordsLinked to original sources

PubMed2006

High-volume hemofiltration as salvage therapy in severe hyperdynamic septic shock.

OBJECTIVES: To evaluate the effect of short-term (12-h) high-volume hemofiltration (HVHF) in reversing progressive refractory hypotension and hypoperfusion in patients with severe hyperdynamic septic shock. To evaluate feasibility and tolerance and to compare observed vs. expected hospital mortality. DESIGN AND SETTING: Prospective, interventional, nonrandomized study in the surgical-medical intensive care unit of an academic tertiary center. PATIENTS: Twenty patients with severe septic shock, previously unresponsive to a multi-intervention approach within a goal-directed, norepinephrine-based algorithm, with increasing norepinephrine (NE) requirements (>0.3 microg kg(-1) min(-1)) and lactic acidosis. INTERVENTIONS: Single session of 12-h HVHF. MEASUREMENTS AND RESULTS: We measured changes in NE requirements and perfusion parameters every 4h during HVHF and 6h thereafter. Eleven patients showed decreased NE requirements and lactate levels (responders). Nine patients did not fulfill these criteria (nonresponders). The NE dose, lactate levels, and heart rates decreased and arterial pH increased significantly in responders. Hospital mortality (40%) was significantly lower than predicted (60%): 67% (6/9) in nonresponders vs. 18% (2/11) in responders. Of 12 survivors 7 required only a single 12-h HVHF session. On logistic regression analysis the only statistically significant predictor of survival was theresponse to HVHF (odds ratio 9). CONCLUSIONS: A single session of HVHF as salvage therapy in the setting of a goal-directed hemodynamic management algorithm may be beneficial in severe refractory hyperdynamic septic-shock patients. This approach may improve hemodynamics and perfusion parameters, acid-base status, and ultimately hospital survival. Moreover, it is feasible, and safe.

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PubMed2006

Implementation of a norepinephrine-based protocol for management of septic shock: a pilot feasibility study.

BACKGROUND: The subject of the best vasopressor for hemodynamic management of septic shock (SS) is controversial. One of the difficulties in planning such studies is that physicians are reluctant to use one vasopressor exclusively, and there is considerable variation in practice. The aim of this study was to test the feasibility of implementing a single pressor-based algorithm (in this case, norepinephrine [NE]). METHODS: A NE-based algorithm was applied prospectively to 100 consecutive SS patients. A formal training program was implemented before starting the protocol and applied to 72 physicians and nurses involved in intensive care unit (ICU) patient care. Compliance, protocol violations, probable adverse effects, and outcome were evaluated on a daily basis by an independent group of fellows and a research nurse. RESULTS: In 100 patients, there were 7,139 hours of algorithm use. Only 13 protocol violations were observed, mostly in the timing of inotropic drugs. Senior staff physicians or busy night shifts accounted for most of these violations. ICU mortality was 33%, which is comparable to that predicted by Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores. Adverse events probably related to NE were not observed. CONCLUSIONS: The present algorithm, applied after a strict training program, obtained an overall good acceptance and compliance with very few protocol violations in more than 7,000 hours of use. Safety was demonstrated by a global mortality comparable to that predicted by severity scores and absence of specific drug-related morbidity. The implementation of a single pressor-based algorithm for SS is feasible and safe.

Adult↗

PubMed2005

Management of septic shock with a norepinephrine-based haemodynamic algorithm.

UNLABELLED: Management of septic shock (SS) with a norepinephrine (noradrenaline)-based haemodynamic algorithm. INTRODUCTION: The choice of the best vasopressor for haemodynamic management of septic shock is controversial. Nevertheless, very few studies have been focused on evaluating different management algorithms. The aim of this study was to evaluate the performance of a norepinephrine (NE)-based management protocol. Experience with NE as the initial vasopressor, even if not comparative, could bring relevant data for planning future trails. We also wanted to evaluate the compliance of critical care physicians and nurses with haemodynamic management protocol. PATIENTS AND METHOD: A norepinephrine-based algorithm for the management of septic shock that commands different sequential interventions according to its requirements, was applied prospectively to 100 consecutive septic shock patients. RESULTS: Norepinephrine was used as the first vasoactive drug in all patients with a maximum dose of 0.31+/-0.3 microg kg(-1)min(-1) and an ICU mortality of 33%. Physicians applied correctly all the steps of the algorithm in 92% of the patients. Applying the algorithm, avoided the use of pulmonary artery catheter in 31 patients and led to use of lower doses of vasoactive agents than in many other clinical experiences. CONCLUSION: In conclusion, our data support extended use of an algorithm based on norepinephrine for treating septic shock patients. This is the first clinical study that uses NE as the initial vasopressor drug systematically, and although not comparative, the mortality rates adjusted to APACHE II, are comparable to other studies. It also gives support for future clinical trials comparing norepinephrine with dopamine in this setting.

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PubMed2004

Effects of positive end-expiratory pressure on gastric mucosal perfusion in acute respiratory distress syndrome.

INTRODUCTION: Positive end-expiratory pressure (PEEP) improves oxygenation and can prevent ventilator-induced lung injury in patients with acute respiratory distress syndrome (ARDS). Nevertheless, PEEP can also induce detrimental effects by its influence on the cardiovascular system. The purpose of this study was to assess the effects of PEEP on gastric mucosal perfusion while applying a protective ventilatory strategy in patients with ARDS. METHODS: Eight patients were included. A pressure-volume curve was traced and ideal PEEP, defined as lower inflection point + 2 cmH2O, was determined. Gastric tonometry was measured continuously (Tonocap). After baseline measurements, 10, 15 and 20 cmH2O PEEP and ideal PEEP were applied for 30 min each. By the end of each period, hemodynamic, CO2 gap (gastric minus arterial partial pressures), and ventilatory measurements were performed. RESULTS: PEEP had no effect on CO2 gap (median [range], baseline: 19 [2-30] mmHg; PEEP 10: 19 [0-40] mmHg; PEEP 15: 18 [0-39] mmHg; PEEP 20: 17 [4-39] mmHg; ideal PEEP: 19 [9-39] mmHg; P = 0.18). Cardiac index also remained unchanged (baseline: 4.6 [2.5-6.3] l min(-1) m(-2); PEEP 10: 4.5 [2.5-6.9] l min(-1) m(-2); PEEP 15: 4.3 [2-6.8] l min(-1) m(-2); PEEP 20: 4.7 [2.4-6.2] l min(-1) m(-2); ideal PEEP: 5.1 [2.1-6.3] l min(-1) m(-2); P = 0.08). One patient did not complete the protocol because of hypotension. CONCLUSION: PEEP of 10-20 cmH2O does not affect gastric mucosal perfusion and is hemodynamically well tolerated in most patients with ARDS, including those receiving adrenergic drugs.

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