Fluid and hemodynamic management in hemodialysis patients: challenges and opportunities / Manejo hídrico e hemodinâmico em pacientes em hemodiálise: desafios e oportunidades

Abstract Fluid volume and hemodynamic management in hemodialysis patients is an essential component of dialysis adequacy. Restoring salt and water homeostasis in hemodialysis patients has been a permanent quest by nephrologists summarized by the 'dry weight' probing approach. Although this clinical approach has been associated with benefits on cardiovascular outcome, it is now challenged by recent studies showing that intensity or aggressiveness to remove fluid during intermittent dialysis is associated with cardiovascular stress and potential organ damage. A more precise approach is required to improve cardiovascular outcome in this high-risk population. Fluid status assessment and monitoring rely on four components: clinical assessment, non-invasive instrumental tools (e.g., US, bioimpedance, blood volume monitoring), cardiac biomarkers (e.g. natriuretic peptides), and algorithm and sodium modeling to estimate mass transfer. Optimal management of fluid and sodium imbalance in dialysis patients consist in adjusting salt and fluid removal by dialysis (ultrafiltration, dialysate sodium) and by restricting salt intake and fluid gain between dialysis sessions. Modern technology using biosensors and feedback control tools embarked on dialysis machine, with sophisticated analytics will provide direct handling of sodium and water in a more precise and personalized way. It is envisaged in the near future that these tools will support physician decision making with high potential of improving cardiovascular outcome.

Resumo O volume de fluidos e o controle hemodinâmico em pacientes em hemodiálise é um componente essencial da adequação da diálise. A restauração da homeostase do sal e da água em pacientes em hemodiálise tem sido uma busca constante por parte dos nefrologistas, no que condiz à abordagem do "peso seco. Embora essa abordagem clínica tenha sido associada a benefícios no desfecho cardiovascular, recentemente tem sido questionada por estudos que mostram que a intensidade ou agressividade para remover fluidos durante a diálise intermitente está associada a estresse cardiovascular e dano potencial a órgãos.para remover fluidos durante a diálise intermitente está associada a estresse cardiovascular e dano potencial a órgãos. Uma abordagem mais precisa é necessária para melhorar o desfecho cardiovascular nessa população de alto risco. A avaliação e monitorização do estado hídrico baseiam-se em quatro componentes: avaliação clínica, ferramentas instrumentais não invasivas (por exemplo, US, bioimpedância, monitorização do volume sanguíneo), biomarcadores cardíacos (e.g. peptídeos natriuréticos), algoritmos e modelagem de sódio para estimar a transferência de massa. O manejo otimizado do desequilíbrio hídrico e de sódio em pacientes dialíticos consiste em ajustar a remoção de sal e líquido por diálise (ultrafiltração, dialisato de sódio), e restringir a ingestão de sal e o ganho de líquido entre as sessões de diálise. Tecnologia moderna que utiliza biosensores e ferramentas de controle de feedback, hoje parte da máquina de diálise, com análises sofisticadas, proporcionam o manejo direto sobre o sódio e a água de uma maneira mais precisa e personalizada. Prevê-se no futuro próximo que essas ferramentas poderão auxiliar na tomada de decisão do médico, com alto potencial para melhorar o resultado cardiovascular.

Symptoms of anxiety and depression are related to cardiovascular responses to active, but not passive, coping tasks

Objective: Anxiety and depression have been linked to blunted blood pressure (BP) and heart rate (HR) reactions to mental stress tests; however, most studies have not included indices of underlying hemodynamics nor multiple stress tasks. This study sought to examine the relationships of anxiety and depression with hemodynamic responses to acute active and passive coping tasks. Methods: A total of 104 participants completed the Hospital Anxiety and Depression Scales and mental arithmetic, speech, and cold pressor tasks while BP, HR, total peripheral resistance, and cardiac output (CO) were assessed. Results: After adjustment for traditional risk factors and baseline cardiovascular activity, depression scores were negatively associated with systolic BP, HR, and CO responses to the mental arithmetic task, while anxiety scores were inversely related to the systolic BP response to mental arithmetic. Conclusion: High anxiety or depression scores appear to be associated with blunted cardiac reactions to mental arithmetic (an active coping task), but not to the cold pressor test or speech tasks. Future research should further examine potential mechanisms and longitudinal pathways relating depression and anxiety to cardiovascular reactivity. Clinical trial registration number: TCTR20160208004

Acute but not chronic metabolic acidosis potentiates the acetylcholine-induced reduction in blood pressure: an endothelium-dependent effect

Metabolic acidosis has profound effects on vascular tone. This study investigated the in vivo effects of acute metabolic acidosis (AMA) and chronic metabolic acidosis (CMA) on hemodynamic parameters and endothelial function. CMA was induced by ad libitum intake of 1% NH4Cl for 7 days, and AMA was induced by a 3-h infusion of 6 M NH4Cl (1 mL/kg, diluted 1:10). Phenylephrine (Phe) and acetylcholine (Ach) dose-response curves were performed by venous infusion with simultaneous venous and arterial blood pressure monitoring. Plasma nitrite/nitrate (NOx) was measured by chemiluminescence. The CMA group had a blood pH of 7.15±0.03, which was associated with reduced bicarbonate (13.8±0.98 mmol/L) and no change in the partial pressure of arterial carbon dioxide (PaCO2). The AMA group had a pH of 7.20±0.01, which was associated with decreases in bicarbonate (10.8±0.54 mmol/L) and PaCO2 (47.8±2.54 to 23.2±0.74 mmHg) and accompanied by hyperventilation. Phe or ACh infusion did not affect arterial or venous blood pressure in the CMA group. However, the ACh infusion decreased the arterial blood pressure (ΔBP: -28.0±2.35 mm Hg [AMA] to -4.5±2.89 mmHg [control]) in the AMA group. Plasma NOx was normal after CMA but increased after AMA (25.3±0.88 to 31.3±0.54 μM). These results indicate that AMA, but not CMA, potentiated the Ach-induced decrease in blood pressure and led to an increase in plasma NOx, reinforcing the effect of pH imbalance on vascular tone and blood pressure control.

Dehydration, hemodynamics and fluid volume optimization after induction of general anesthesia

OBJECTIVES: Fluid volume optimization guided by stroke volume measurements reduces complications of colorectal and high-risk surgeries. We studied whether dehydration or a strong hemodynamic response to general anesthesia increases the probability of fluid responsiveness before surgery begins. METHODS: Cardiac output, stroke volume, central venous pressure and arterial pressures were measured in 111 patients before general anesthesia (baseline), after induction and stepwise after three bolus infusions of 3 ml/kg of 6% hydroxyethyl starch 130/0.4 (n = 86) or Ringer's lactate (n = 25). A subgroup of 30 patients who received starch were preloaded with 500 ml of Ringer's lactate. Blood volume changes were estimated from the hemoglobin concentration and dehydration was estimated from evidence of renal water conservation in urine samples. RESULTS: Induction of anesthesia decreased the stroke volume to 62% of baseline (mean); administration of fluids restored this value to 84% (starch) and 68% (Ringer's). The optimized stroke volume index was clustered around 35-40 ml/m2/beat. Additional fluid boluses increased the stroke volume by ≥10% (a sign of fluid responsiveness) in patients with dehydration, as suggested by a low cardiac index and central venous pressure at baseline and by high urinary osmolality, creatinine concentration and ...

Assistência circulatória em choque cardiogênico pós-infarto agudo do miocárdio / Circulatory support in cardiogenic shock after acute myocardial infarction

Em pacientes com insuficiência coronariana aguda e choque cardiogênico, a mortalidade é alta. O dispositivo mais utilizado para suporte hemodinâmico é o balão intra-aórtico que, no entanto, pode ser insuficiente em pacientes com choque cardiogênico refratário. Relato de caso com dois dias de dor precordial opressiva e intensa, irradiada para membro superior esquerdo. ECG com supradesnivelamento anterior. Realizado angioplastia e implante de stent na artéria descendente anterior. Evolução com choque cardiogênico refratário ao uso de drogas vasoativas e balão intra-aórtico. Foram realizadas medidas hemodinâmicas e decidiu-se pela colocação do Impella® 2,5 por via percutânea para assistência circulatória.

Mortality is high in patients with acute coronary failure and cardiogenic shock. The most commonly used device for hemodynamic support is the intra-aortic balloon, which, however, may be insufficient in patients with refractory cardiogenic shock. This is a case report of a patient complaining of two days of intense and oppressive chest pain, radiating to the left arm. The ECG showed ST elevation. The patient was submitted to angioplasty and stent implant in the anterior descending artery and developed cardiogenic shock refractory to vasoactive drugs and intra-aortic balloon. Hemodynamic measures were carried out and we chose to use an Impella 2.5 device, by percutaneous route, for circulatory support.

Resultados preliminares y factibilidad del mini lavado bronco-alveolar en pacientes cursando falla respiratoria severa / Mini bronchoalveolar lavage in patients with severe respiratory failure

Background: To recognize the etiological agent responsible for severe acute respiratory failure (ARF) in patients in mechanical ventilation (MV) is important to determine their treatment and prognosis, and to avoid the excessive use of antibiotics. Mini bronchoalveolar lavage (mini BAL) is a blind, non bronschoscopic procedure, used to obtain samples from the lower respiratory tract from patients on mechanical ventilation (MV). Aim: To assess the feasibility, complications and preliminary results of mini BAL among patients with severe ARF on MV. Material and Methods: Prospective study in 17 patients with acute lung injury (ALI ) or acute respiratory distess syndrome (ARDS) on MV and with negative conventional microbiological studies. Mini BAL was performed using standardized protocols. Hemodynamic and respiratory parameters where measured before and after the procedure. Samples obtained were sent to quantitative cultures. Results: At baseline: APACHE II score of 22 ± 6,7, PaO2/FiO2 ratio was 176.6 ± 48.6 and the oxygenation index was 9.74 ± 3.78. All procedures were performed by an ICU resident. Thirty five percent of the procedures had positive cultures and no complications related to the procedures were reported. The procedure lasted an average of 12 minutes and the instilled and rescued volume were 60 ml and 19.6 ml, respectively. There were no significant differences between hemodynamic and respiratory variables before and after the procedure. Conclusions: Mini BAL is a safe, fast and easy technique for obtaining samples from the inferior airway in patients with ALI or ARDS on MV.

Correlation between the hemodynamic gain obtained after operation of primary varicose veins and chronic venous disease classification / Correlação entre o ganho hemodinâmico obtido após a operação de varizes dos membros inferiores e a classificação da doença venosa crônica

CONTEXT: Previous studies have demonstrated improvement of venous hemodynamics after surgical treatment of primary varicose veins of the lower extremities using air plethysmography (APG). PURPOSE: To correlate the venous hemodynamics obtained by APG with the CEAP classification after surgical treatment of primary varicose veins. METHODS: We studied 63 limbs of 39 patients (35 women and 4 men) aged on average 46.3 years, operated upon at the University Hospital, Faculty of Medicine of Ribeirão Preto, University of São Paulo, during the period from January 2001 to December 2004. The 63 limbs were divided into the three following groups according to CEAP classification: group C2 + C3 (38 limbs), group C4 (15 limbs) and group C5 + C6 (10 limbs). The patients were evaluated clinically before and 30 to 40 days after surgery by preoperative duplex ultrasonography and pre- and postoperative APG. RESULTS: There was an apparent hemodynamic improvement after surgical treatment of the varicose veins in the two groups of lower severity, but the improvement was significant in the most severe group based on venous filling index. CONCLUSION : Surgical treatment was beneficial for all three groups, but the greatest hemodynamic gain was observed in the group of highest clinical severity (group C5 + C6).

CONTEXTO: Estudos prévios tem demonstrado a melhora da hemodinâmica venosa após o tratamento cirúrgico das varizes primárias dos membros inferiores utilizando a pletismografia a ar (PGA). OBJETIVO: Correlacionar a hemodinâmica venosa obtida pela PGA com a classificação CEAP após tratamento cirúrgico das varizes primárias dos membros inferiores. MÉTODOS: Foram estudados 63 membros inferiores em 39 pacientes (35 mulheres e 4 homens), com idade média igual a 46,3 anos, operados no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, no período de janeiro de 2001 a dezembro de 2004. Os 63 membros inferiores foram subdivididos em três grupos de acordo com a classificação CEAP, adotando-se o critério lesão de pele como referência, sendo: grupo C2 + C3 (38 membros) grupo C4 (15 membros) e grupo C5 + C6 (10 membros). Os pacientes foram avaliados clinicamente pré e pós-operatório (30 a 40 dias após), mapeamento dúplex pré-operatório e PGA pré e pós-operatória. RESULTADOS: Houve aparente melhora hemodinâmica após tratamento cirúrgico de varizes nos dois grupos de menor gravidade, mas foi significativa no de maior gravidade com base no índice de enchimento venoso. CONCLUSÃO: O tratamento cirúrgico beneficiou os três grupos, mas o maior ganho hemodinâmico foi observado no grupo de gravidade clínica maior (grupo C5 + C6).

Clinical and haemodynamic evaluation of chronic thromboembolic pulmonary hypertension patients scheduled for pulmonary thromboendarterectomy: Is schistosomiasis hypertension an important confounding factor?

INTRODUCTION: Chronic thromboembolic pulmonary hypertension is a disease affecting approximately 4,000 people per year in the United States. The incidence rate in Brazil, however, is unknown. The estimated survival for patients with chronic thromboembolic pulmonary hypertension without treatment is approximately three years. Pulmonary thromboendarterectomy for select patients is a potentially curative procedure when correctly applied. In Brazil, the clinical and hemodynamic profiles of chronic thromboembolic pulmonary hypertension patients have yet to be described. OBJECTIVES: To evaluate the clinical and hemodynamic characteristics of chronic thromboembolic pulmonary hypertension patients scheduled for pulmonary thromboendarterectomy in a referral center for chronic thromboembolic pulmonary hypertension treatment in Brazil. METHODS: From December 2006 to November 2009, patients were evaluated and scheduled for pulmonary thromboendarterectomy. The subjects were classified according to gender, age and functional class and were tested for thrombofilia and brain natriuretic peptide levels. RESULTS: Thirty-five consecutive chronic thromboembolic pulmonary hypertension patients were evaluated. Two patients tested positive for schistosomiasis, and 31 were enrolled in the study (19 female, 12 male). The majority of patients were categorized in functional classes III and IV. Hemodynamic data showed a mean pulmonary vascular resistance (PVR) of 970.8 ± 494.36 dynas·s·cm-5 and a low cardiac output of 3.378 ± 1.13 L/min. Linear regression revealed a direct relation between cardiac output and pulmonary vascular resistance. Paradoxical septal movement was strongly correlated with pulmonary vascular resistance and cardiac output (p=0.001). Brain natriuretic peptide serum levels were elevated in 19 of 27 patients. CONCLUSIONS: In a referral center for pulmonary hypertension in Brazil, chronic thromboembolic pulmonary hypertension patients evaluated for pulmonary thromboendarterectomy had a hemodynamically severe status and had elevated brain natriuretic peptide serum levels. There was a predominance of females in our cohort, and the prevalence of hematological disorders and schistosomiasis was low (less than 10 percent).

Morphological and hemodynamic patterns of carotid stenosis treated by endarterectomy with patch closure versus stenting: a duplex ultrasound study

OBJECTIVES: A duplex ultrasound study was performed to investigate morphological and hemodynamic patterns of carotid stenoses treated by endarterectomy with patch closure versus stenting. MATERIALS AND METHOD: Twenty-nine carotid stenoses were treated with stenting and 65 with patch closure. Duplex ultrasound parameters (luminal diameter, mm; peak systolic velocity and end-diastolic velocity, cm/s) were measured 24 hours after the procedures and also at 12 months post-procedure. Residual stenoses (immediately postprocedure) and restenoses (within 12 months of procedure) were defined as narrowings of >50 percent on duplex ultrasound examination. RESULTS: In stented patients, the luminal diameter of the proximal internal carotid artery increased in the interval between the 24-hour and 12-month post-procedure studies, while in the patch closure patients, the diameter decreased. Carotid hemodynamics normalized immediately after both patching and stenting and remained relatively stable thereafter up to 12 months. No statistically elevated flow velocities (in the absence of residual stenosis or restenosis) were observed in the patched or stented carotid arteries. No significant differences in residual stenosis rates were observed between the stenting group (3 cases, 10.34 percent) and the patch closure group (1 case, 1.53 percent, P = 0.08). At 12 months, 2 stenting patients (6.88 percent) and 2 patch closure patients (3.07 percent) had $50 percent restenosis (P = 0.58). One case of late stroke due to restenosis was observed in the stenting group; the patient died 12 months postoperatively, before receiving new intervention. CONCLUSION: Measurements over time in luminal diameter signalized differences in arterial remodeling mechanisms between patched and stented carotids. Both stenting and patch closure were associated with carotid patency and flow restoration. This study does not support a general approach to new velocity criteria indiscriminately applied to stented or patched carotids.

Short-term effects of positive expiratory airway pressure in patients being weaned from mechanical ventilation

OBJECTIVE: To investigate the feasibility and the cardiorespiratory effects of using positive expiratory airway pressure, a physiotherapeutic tool, in comparison with a T-tube, to wean patients from mechanical ventilation. METHODS/DESIGN: A prospective, randomized, cross-over study. SETTING: Two intensive care units. PATIENTS AND INTERVENTIONS: We evaluated forty patients who met weaning criteria and had been mechanically-ventilated for more than 48 hours, mean age 59 years, including 23 males. All patients were submitted to the T-tube and Expiratory Positive Airway Pressure devices, at 7 cm H2O, during a 30-minute period. Cardiorespiratory variables including work of breathing, respiratory rate (rr), peripheral oxygen saturation (SpO2), heart rate (hr), systolic, diastolic and mean arterial pressures (SAP, DAP, MAP) were measured in the first and thirtieth minutes. The condition was analyzed as an entire sample set (n=40) and was also divided into subconditions: chronic obstructive pulmonary disease (n=14) and non-chronic obstructive pulmonary disease (non- chronic obstructive pulmonary disease) (n=26) categories. Comparisons were made using a t-test and Analysis of Variance. The level of significance was p < 0.05. RESULTS: Our data showed an increase in work of breathing in the first and thirtieth minutes in the EPAP condition (0.86+ 0.43 and 1.02+1.3) as compared with the T-tube condition (0.25+0.26 and 0.26+0.35) (p<0.05), verified by the flow-sensor monitor (values in J/L). No statistical differences were observed when comparing the Expiratory Positive Airway Pressure and T-tube conditions with regard to cardiorespiratory measurements. The same result was observed for both chronic obstructive pulmonary disease and non- chronic obstructive pulmonary disease subconditions. CONCLUSIONS: Our study demonstrated that, in weaning patients from mechanical ventilation, the use of a fixed level of Expiratory Positive Airway Pressure caused ...

Alta utilidad de monitorización hemodinámica con ecocardiografía transesofágica intraoperatoria en cirugía ortopédica / Intraoperative hemodynamic monitoring using transesophageal echocardiography in orthopedic surgery

Background: Orthopedic surgery is commonly performed in elderly patients with higher cardiovascular surgical risk. Hemodynamic monitoring in these patients may prevent perioperative complications. Aim: To assess the usefulness of transesophageal echocargiography (TEE) for intraoperative cardiovascular monitoring during orthopedic surgery. Material and methods: Patients older than 65 years subjected to orthopedic surgery using general anesthesia and with a high cardiovascular risk were studied. Intraoperative TEE was performed to assess intravascular volume, myocardial contractility and the presence of myocardial ischemia. Results: Fifty three patients aged 72±5 years were studied. Hemodynamic stability was detected in 68 percent of patients, mainly reflected as episodes of hypovolemia. Myocardial ischemia was detected in two patients and embolic episodes in six (11 percent). Conclusions: Intraoperative TEE was useful for the hemodynamic evaluation of patients with high cardiovascular risk.

Daño pulmonar agudo asociado a ventilación mecánica / Ventilator associated acute lung injury

Mechanical ventilation plays a central role In the critical care setting; but its use is closely related with some life threatening complications as nosocomial pneumonia and low cardiac performance. One of the most severe complications is called ventilator-associated lung injury (VALI) and it includes: Barotrauma, volutrauma, atelectrauma, biotrauma and oxygen-mediated toxic effects and it is related with an inflammatory response secondary to the stretching and recruitment process of alveoli within mechanical ventilation. The use of some protective ventilatory strategies has lowered the mortality rate 10% approximately.

La importancia de la asistencia mecánica ventilatoria (AMV) en la Unidad de Cuidados Intensivos (UCI) es indiscutible; sin embargo, su uso está ligado con complicaciones como neumonía nosocomial y deterioro del rendimiento cardiaco, que en algunas ocasiones ponen en peligro la vida del enfermo. Una de las complicaciones más graves es el daño pulmonar asociado a la ventilación mecánica (DPVM). El DPVM se caracteriza por la presencia de edema pulmonar rico en proteínas. Se recomienda establecer cierto número de estrategias de protección pulmonar (EPP) para prevenir este tipo de lesión. Una vez instituidas, las EPP han demostrado una disminución de la mortalidad de aproximadamente 10%.

La hemodinamia cardiopulmonar en el paciente neumópata crónico. Un comentario clínico / Cardiopulmonary haemodynamic in chronic neumologic patients. A clinical comment

Las enfermedades pulmonares crónicas son una causa frecuente de hipertensión pulmonar y cor pulmonale crónico, su existencia implica una menor supervivencia y por lo tanto mal pronóstico. Esta revisión analiza los probables factores fisiopatológicos que participan en la génesis de la hipertensión pulmonar de nuestros tres primeros grupos de trabajo (enfermedad pulmonar obstructiva crónica, neumopatía intersticial y apnea obstructiva del sueño). En general, la hipertensión pulmonar de este grupo de pacientes es el resultado de uno o varios factores: factores vasoactivos (hipoxia, acidosis, etcétera), factores pasivos (hiperflujo, hipertensión venocapilar y daño vascular); este último factor a su vez puede ser mediado por la patología de base (fibrosis, inflamación, obstrucción, etcétera) o bien ser secundario a remodelación de la circulación pulmonar por hipoxia crónica e hiperflujo. Otros factores de origen funcional descritos han sido la disminución del volumen pulmonar propia de las patologías intersticiales; así como el aumento en la resistencia de la vía aérea y la eritrocitosis secundaria, hallazgos que caracterizan a la enfermedad pulmonar obstructiva crónica. El adecuado conocimiento en la fisiopatología de estas enfermedades, así como la magnitud de la hipertensión pulmonar requiere del estudio de la circulación pulmonar a través del cateterismo cardiaco derecho por lo que se justifica la existencia de un servicio de hemodinamia en todo hospital dedicado a la enseñanza de la neumología.

Morbidade em pacientes sem doença cardiovascular avaliada pela correlaçäo entre o eletrocardiograma pré-operatório e a eletrocardiografia intra e pós-operatória / Healthy cardiovascular patient morbidity evaluated by preoperative electrocardiogram and perioperative electrocardiographic correlation

A preocupaçäo em se determinar os riscos e a morbidade associados ao ato anestésico tem sido constante, já que é possível estabelecerem-se medidas que impeçam o surgimento de complicaçöes e culminem com melhora dos resultados. Estudamos pacientes sem doença cardiovascular, analisando os resultados de seus eletrocardiogramas pré-operatórios e verificando se os mesmos prenunciavam alteraçöes da eletrocardiografia intra e pós-operatória. Verificamos se essas alteraçöes implicavam em distúrbios hemodinâmicos e se haviam fatores determinantes das mesmas, relacionados ao ato anestésico-cirúrgico. Os resultados mostraram a presença de alteraçöes do eletrocardiograma (ECG) pré-operatório em incidência crescente, conforme o avanço da idade, e a ocorrência freqüente de alteraçöes da eletrocardiografia, intra e pós-operatória, mas näo relacionadas ao ECG e nem motivando distúrbios hemodinâmicos. Os resultados obtidos nos permitem concluir que, em pacientes sem doença cardiovascular: (1) a incidência de alteraçöes do ECG pré-operatório é maior, quanto mais idosos forem os pacientes; (2) alteraçöes da eletrocardiografia intra-operatória säo comuns e conseqüências de eventos do próprio ato anestésico-cirúrgico; na sala de recuperaçäo anestésica näo säo freqüentes e, quando existem, relacionam-se, principalmente, ao estresse do despertar e da extubaçäo; (3) essas alteraçöes hemodinâmicas importantes e (4) o ECG pré-operatório näo prenuncia e näo se relaciona com essas alteraçöes.

Líquidos parenterales totales y su relación con enfermedad pulmonar crónica en el neonato / Total parenteral fluids and their relation with chronic lung disease in neonates

La mayor sobrevida de neonatos de bajo peso se ha asociado a un aumento en la incidencia de enfermedad pulmonar crónica. Se sabe que el edema pulmonar acompaña al síndrome de dificultad respiratoria y por lo tanto la cantidad y tipo de soluciones administradas pudieran modificar la evolución de estos pacientes al requerir mayor FiO2, mayor presión inspiratoria máxima, y mayor presión media de vías aéreas. Este estudio se realizó con el objeto de determinar si en un grupo de neonatos criticamente enfermos la cantidad de líquidos administrados y la variación de peso durante los primeros 5 días de vida estaba en relación directa o se asociaba al desarrollo de enfermedad pulmonar crónica (EPC). Se revisaron los expedientes de pacientes sometidos a ventilación mecánica por un período mínimo de 3 días durante la primera semana y que sobrevivieron a los 28 días de vida. Grupo I: 14 pacientes con diagnóstico de enfermedad pulmonar crónica y Grupo II: 14 pacientes sin diagnóstico de EPC. Se determinó la cantidad de líquidos totales administrados/kg/día y el peso durante los primeros 5 días de vida. Los resultados no mostraron diferencia significativa entre la cantidad de líquidos administrados y variación de peso en la población estudiada. Se conluye que el aporte hídrico utilizado en esta población es bajo y no tuvo relación con el desarrollo de EPC