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1.
Clin Biochem ; 74: 69-72, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31473201

RESUMO

BACKGROUND: S100B protein is one of the most accurate biomarkers for diagnosis of neuroapoptosis and brain damage. The aim was to evaluate the lactate concentration and acid-base balance (pH, pCO2, pO2, HCO3c and BEb) in umbilical cord blood to predict high risk of neuroapoptosis and analyze the relationship between the levels of these biomarkers and umbilical cord blood S100B protein concentration at birth. METHODS: Apparently healthy newborns were included. S100B protein and blood gas test (lactate and acid-base balance) were determined in umbilical cord blood at birth. Newborns were classified into two groups: with and without high risk of neuroapoptosis. Newborns with high umbilical cord blood S100B protein concentration were considered newborns at high risk of neuroapoptosis. RESULTS: Sixty-one newborns were included, 12 had high risk of neuroapoptosis and 49 did not. S100B protein concentration correlate directly with pCO2 levels (Rho: 0.286, p = .0321) and lactate concentration (Rho: 0.278, p = .0315); and indirectly with pH (Rho: -0.332, p = .01). The analysis of the ROC curves yielded significant curves for pH and pCO2 to predict high risk of neuroapoptosis, pH optimal cutoff value was 7.19 (sensitivity: 50%, specificity: 83.7%, AUC: 0.708); and pCO2 optimal cutoff value was 60 mmHg (sensitivity: 30%, specificity: 85.4%, AUC: 0.705). CONCLUSIONS: Respiratory acidosis is associated to high concentrations of S100B protein in umbilical cord blood at birth. Umbilical cord blood pH and pCO2 may be useful in differentiating newborns at high risk of neuroapoptosis. Umbilical cord blood gas test may be valuable as risk indicator for neuroapoptosis at birth.


Assuntos
Acidose Respiratória/sangue , Acidose Respiratória/patologia , Apoptose , Encéfalo/patologia , Sangue Fetal/química , Adolescente , Adulto , Biomarcadores/sangue , Gasometria , Dióxido de Carbono/sangue , Estudos Transversais , Feminino , Hipóxia Fetal/sangue , Humanos , Concentração de Íons de Hidrogênio , Recém-Nascido , Ácido Láctico/sangue , Masculino , Neurônios/patologia , Curva ROC , Subunidade beta da Proteína Ligante de Cálcio S100/sangue , Sensibilidade e Especificidade , Adulto Jovem
4.
J Intensive Care Med ; 33(2): 128-133, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29141525

RESUMO

BACKGROUND: Acute heart failure (AHF) is one of the leading causes of admission to emergency department (ED); severe hypoxemic AHF may be treated with noninvasive ventilation (NIV). Despite the demonstrated clinical efficacy of NIV in relieving symptoms of AHF, less is known about the hyperacute effects of bilevel positive airway pressure (BiPAP) ventilation on hemodynamics of patients admitted to ED for AHF. We therefore aimed to assess the effect of BiPAP ventilation on principal hemodynamic, respiratory, pulse oximetry, and microcirculation indexes in patients admitted to ED for AHF, needing NIV. METHODS: Twenty consecutive patients admitted to ED for AHF and left ventricular systolic dysfunction, needing NIV, were enrolled in the study; all patients were treated with NIV in BiPAP mode. The following parameters were measured at admission to ED (T0, baseline before treatment), 3 hours after admission and initiation of BiPAP NIV (T1), and after 6 hours (T2): arterial blood oxygenation (pH, partial pressure of oxygen in the alveoli/fraction of inspired oxygen ratio, Paco2, lactate concentration, HCO3-), hemodynamics (tricuspid annular plane systolic excursion, transpulmonary gradient, transaortic gradient, inferior vena cava diameter, brain natriuretic peptide [BNP] levels), microcirculation perfusion (end-tidal CO2 [etco2], peripheral venous oxygen saturation [SpvO2]). RESULTS: All evaluated indexes significantly improved over time (analysis of variance, P < .001 in quite all cases.). CONCLUSIONS: The BiPAP NIV may rapidly ameliorate several hemodynamic, arterial blood gas, and microcirculation indexes in patients with AHF and left ventricular systolic dysfunction.


Assuntos
Acidose Respiratória/terapia , Pressão Positiva Contínua nas Vias Aéreas/métodos , Insuficiência Cardíaca Sistólica/terapia , Hemodinâmica , Hipercapnia/terapia , Hipóxia/terapia , Insuficiência Respiratória/terapia , Disfunção Ventricular Esquerda/terapia , Acidose Respiratória/sangue , Acidose Respiratória/etiologia , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Ecocardiografia , Serviço Hospitalar de Emergência , Feminino , Insuficiência Cardíaca Sistólica/sangue , Insuficiência Cardíaca Sistólica/complicações , Insuficiência Cardíaca Sistólica/diagnóstico por imagem , Humanos , Concentração de Íons de Hidrogênio , Hipercapnia/sangue , Hipercapnia/etiologia , Hipóxia/sangue , Hipóxia/etiologia , Modelos Lineares , Masculino , Microcirculação , Análise Multivariada , Peptídeo Natriurético Encefálico/sangue , Ventilação não Invasiva , Oximetria , Estudos Prospectivos , Insuficiência Respiratória/sangue , Insuficiência Respiratória/etiologia , Disfunção Ventricular Esquerda/sangue , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Esquerda/diagnóstico por imagem
6.
Heart Lung ; 46(3): 149-152, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28392039

RESUMO

BACKGROUND: Clinicians frequently assume that during arterial puncture for measuring arterial blood gases patients hyperventilate from pain and anxiety. This assumption leads clinicians to falsely interpret a PaCO2 and pH near the upper limit of normal as a chronic respiratory acidosis corrected by an acute respiratory alkalosis. OBJECTIVE: Determine if participants hyperventilate during arterial puncture from pain and anxiety. METHODS: We recruited participants from a pulmonary function laboratory referred for arterial blood gas measurement. We excluded those with heart failure and included those with any respiratory condition (COPD, asthma, sleep apnea). We measured end tidal PCO2 (PETCO2), respiratory rate, and heart rate 15 min before topical anesthesia, during anesthesia, during arterial puncture, and 15 min later. We assessed generalized anxiety before and measured pain during and after arterial puncture. RESULTS: 24 participants were recruited (age: 54 ± 12 years; men: 54%). PaCO2 was 41 ± 5 mmHg. One had acute respiratory alkalosis. Respiratory rate increased from (19 ± 6 breaths per minute (bpm)) before to a maximum (21 ± 6 bpm) during arterial puncture (p = 0.001). Heart rate was stable throughout. The lowest PETCO2 during the procedure (35 ± 5) was similar to PETCO2 before the procedure (p = 0.1). The change in PETCO2 and respiratory rate did not correlate with pain, anxiety, or lung function. CONCLUSION: Respiratory rate increased slightly during arterial puncture without any change in PETCO2. Hence, acid-base status must be interpreted without the assumption of procedure induced hyperventilation.


Assuntos
Acidose Respiratória/fisiopatologia , Artérias/cirurgia , Dióxido de Carbono/sangue , Hiperventilação/fisiopatologia , Monitorização Fisiológica/métodos , Punções/métodos , Respiração , Acidose Respiratória/sangue , Gasometria , Feminino , Humanos , Hiperventilação/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
8.
J Comp Physiol B ; 187(7): 985-994, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28283796

RESUMO

White sturgeon (Acipenser transmontanus) completely protect intracellular tissue pH (pHi) despite large reductions in extracellular (blood) pH (pHe), termed preferential pHi regulation, in response to elevated environmental PCO2 (hypercarbia) and in general appear to be relatively resilient to stressors. Preferential pHi regulation is thought to be associated with hypercarbia tolerance in general, but has also recently been observed to protect pHi against metabolic acidoses induced by exhaustive exercise and anoxia in a tropical air breathing catfish. We hypothesized that preferential pHi regulation may also be a general strategy of acid-base regulation in sturgeon. To address this hypothesis, severe acidoses were imposed to reduce pHe, and the presence or absence of preferential pHi regulation was assessed in red blood cells (RBC), heart, brain, liver and white muscle. A respiratory acidosis was imposed using hyperoxia, while metabolic acidoses were induced by exhaustive exercise, anoxia or air exposure. Reductions in pHe occurred following hyperoxia (0.15 units), exhaustive exercise (0.30 units), anoxia (0.10 units) and air exposure (0.35 units); all acidoses reduced RBC pHi. Following hyperoxia, heart, brain and liver pHi were preferentially regulated against the reduction in pHe, similar to hypercarbia exposure. Following all metabolic acidoses heart pHi was protected and brain pHi remained unchanged following exhaustive exercise and air exposure, however, brain pHi was reduced following anoxia. Liver and white muscle pHi were reduced following all metabolic acidoses. These results suggest preferential pHi regulation may be a general strategy during respiratory acidoses but during metabolic acidoses, the response differs between source of acidoses and tissues.


Assuntos
Equilíbrio Ácido-Base , Acidose Láctica/sangue , Acidose Respiratória/sangue , Peixes/sangue , Animais , Encéfalo/metabolismo , Dióxido de Carbono/sangue , Cloretos/sangue , Eritrócitos/metabolismo , Hematócrito , Concentração de Íons de Hidrogênio , Hiperóxia/sangue , Hipóxia/sangue , Ácido Láctico/sangue , Fígado/metabolismo , Fibras Musculares de Contração Rápida/metabolismo , Miocárdio/metabolismo , Esforço Físico , Fatores de Tempo
9.
Am J Emerg Med ; 35(4): 548-553, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28007319

RESUMO

OBJECTIVE: To determine whether the presence of nasal flaring is a clinical sign of respiratory acidosis in patients attending emergency departments for acute dyspnea. METHODS: Single-center, prospective, observational study of patients aged over 15 requiring urgent attention for dyspnea, classified as level II or III according to the Andorran Triage Program and who underwent arterial blood gas test on arrival at the emergency department. The presence of nasal flaring was evaluated by two observers. Demographic and clinical variables, signs of respiratory difficulty, vital signs, arterial blood gases and clinical outcome (hospitalization and mortality) were recorded. Bivariate and multivariate analyses were performed using logistic regression models. RESULTS: The sample comprised 212 patients, mean age 78years (SD=12.8), of whom 49.5% were women. Acidosis was recorded in 21.2%. Factors significantly associated with the presence of acidosis in the bivariate analysis were the need for pre-hospital medical care, triage level II, signs of respiratory distress, presence of nasal flaring, poor oxygenation, hypercapnia, low bicarbonates and greater need for noninvasive ventilation. Nasal flaring had a positive likelihood ratio for acidosis of 4.6 (95% CI 2.9-7.4). In the multivariate analysis, triage level II (aOR 5.16; 95% CI: 1.91 to 13.98), the need for oxygen therapy (aOR 2.60; 95% CI: 1.13-5.96) and presence of nasal flaring (aOR 6.32; 95% CI: 2.78-14.41) were maintained as factors independently associated with acidosis. CONCLUSIONS: Nasal flaring is a clinical sign of severity in patients requiring urgent care for acute dyspnea, which has a strong association with acidosis and hypercapnia.


Assuntos
Acidose Respiratória/fisiopatologia , Dispneia/fisiopatologia , Hipercapnia/fisiopatologia , Nariz , Acidose Respiratória/sangue , Acidose Respiratória/terapia , Idoso , Idoso de 80 Anos ou mais , Gasometria , Estudos de Casos e Controles , Dispneia/sangue , Dispneia/terapia , Serviço Hospitalar de Emergência , Feminino , Humanos , Hipercapnia/sangue , Hipercapnia/terapia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Ventilação não Invasiva , Oxigenoterapia , Exame Físico , Estudos Prospectivos , Índice de Gravidade de Doença , Triagem
10.
Top Companion Anim Med ; 31(1): 27-34, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27451046

RESUMO

Acid-base and respiratory disturbances are common in sick and hospitalized veterinary patients; therefore, blood gas analyzers have become integral diagnostic and monitoring tools. This article will discuss uses of blood gas analyzers, types of samples that can be used, sample collection methods, potential sources of error, and potential alternatives to blood gas analyzers and their limitations. It will also discuss the types of analyzers that are available, logistical considerations that should be taken into account when purchasing an analyzer, and the basic principles of how these analyzers work.


Assuntos
Acidose Respiratória/veterinária , Gasometria/veterinária , Doenças do Gato/diagnóstico , Doenças do Cão/diagnóstico , Testes Imediatos , Acidose Respiratória/sangue , Acidose Respiratória/diagnóstico , Animais , Gasometria/instrumentação , Gasometria/métodos , Doenças do Gato/sangue , Gatos , Doenças do Cão/sangue , Cães , Medicina Veterinária
11.
Respirology ; 21(1): 128-36, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26603971

RESUMO

BACKGROUND AND OBJECTIVE: Patients with chronic obstructive pulmonary disease (COPD) experiencing acute exacerbation (AE-COPD) with decompensated respiratory acidosis are known to have poor outcomes in terms of recurrent respiratory failure and death. However, the outcomes of AE-COPD patients with compensated respiratory acidosis are not known. METHODS: We performed a 1-year prospective, single-centre, cohort study in patients surviving the index admission for AE-COPD to compare baseline factors between groups with normocapnia, compensated respiratory acidosis and decompensated respiratory acidosis. Survival analysis was done to examine time to readmissions, life-threatening events and death. RESULTS: A total of 250 patients fulfilling the inclusion and exclusion criteria were recruited and 245 patients were analysed. Compared with normocapnia, both compensated and decompensated respiratory acidosis are associated with lower FEV1 % (P < 0.001), higher GOLD stage (P = 0.003, <0.001) and higher BODE index (P = 0.038, 0.001) and a shorter time to life-threatening events (P < 0.001). Comparing compensated and decompensated respiratory acidosis, there was no difference in FEV1 (% predicted) (P = 0.15), GOLD stage (P = 0.091), BODE index (P = 0.158) or time to life-threatening events (P = 0.301). High PaCO2 level (P = 0.002) and previous use of non-invasive ventilation (NIV) in acute setting (P < 0.001) are predictive factors of future life-threatening events by multivariate analysis. CONCLUSIONS: Compared with normocapnia, both compensated and decompensated respiratory acidosis are associated with poorer lung function and higher risk of future life-threatening events. High PaCO2 level and past history of NIV use in acute settings were predictive factors for future life-threatening events. Compensated respiratory acidosis warrants special attention and optimization of medical therapy as it poses risk of life-threatening events.


Assuntos
Acidose Respiratória , Hospitalização/estatística & dados numéricos , Doença Pulmonar Obstrutiva Crônica , Insuficiência Respiratória , Acidose Respiratória/sangue , Acidose Respiratória/diagnóstico , Acidose Respiratória/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Gasometria/métodos , Estudos de Coortes , Feminino , Hong Kong/epidemiologia , Humanos , Masculino , Ventilação não Invasiva/métodos , Ventilação não Invasiva/estatística & dados numéricos , Projetos Piloto , Prognóstico , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Testes de Função Respiratória/métodos , Insuficiência Respiratória/sangue , Insuficiência Respiratória/diagnóstico , Insuficiência Respiratória/fisiopatologia , Medição de Risco , Análise de Sobrevida , Exacerbação dos Sintomas
13.
ASAIO J ; 61(5): 533-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26273934

RESUMO

Acidification of blood entering a membrane lung (ML) with lactic acid enhances CO2 removal (VCO2ML). We compared the effects of infusion of acetic, citric, and lactic acids on VCO2ML. Three sheep were connected to a custom-made circuit, consisting of a Hemolung device (Alung Technologies, Pittsburgh, PA), a hemofilter (NxStage, NxStage Medical, Lawrence, MA), and a peristaltic pump recirculating ultrafiltrate before the ML. Blood flow was set at 250 ml/min, gas flow (GF) at 10 L/min, and recirculating ultrafiltrate flow at 100 ml/min. Acetic (4.4 M), citric (0.4 M), or lactic (4.4 M) acids were infused in the ultrafiltrate at 1.5 mEq/min, for 2 hours each, in randomized fashion. VCO2ML was measured by the Hemolung built-in capnometer. Circuit and arterial blood gas samples were collected at baseline and during acid infusion. Hemodynamics and ventilation were monitored. Acetic, citric, or lactic acids similarly enhanced VCO2ML (+35%), from 37.4 ± 3.6 to 50.6 ± 7.4, 49.8 ± 5.6, and 52.0 ± 8.2 ml/min, respectively. Acids similarly decreased pH, increased pCO2, and reduced HCO3 of the post-acid extracorporeal blood sample. No significant effects on arterial gas values, ventilation, or hemodynamics were observed. In conclusion, it is possible to increase VCO2ML by more than one-third using any one of the three metabolizable acids.


Assuntos
Acidose Respiratória/sangue , Cálcio/sangue , Dióxido de Carbono/sangue , Ácidos Carboxílicos/farmacologia , Circulação Extracorpórea/métodos , Respiração Artificial/métodos , Ácido Acético/metabolismo , Ácido Acético/farmacologia , Acidose Respiratória/tratamento farmacológico , Acidose Respiratória/cirurgia , Animais , Gasometria , Cálcio/metabolismo , Dióxido de Carbono/metabolismo , Ácido Cítrico/metabolismo , Ácido Cítrico/farmacologia , Feminino , Hemodinâmica , Ácido Láctico/metabolismo , Ácido Láctico/farmacologia , Ovinos
14.
Respir Physiol Neurobiol ; 217: 1-7, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26099799

RESUMO

INTRODUCTION: In spontaneously breathing mice anesthetized with pentobarbital, we observed unexpected paradoxical bradypnea following 5% inhaled CO2. METHODS: Observational study 7-8 week CB6F1/OlaHsd mice (n = 99), anesthetized with 30 mg/kg intraperitoneal pentobarbital. Interventional study: Adult male Wistar rats (n = 18), anesthetized either with 30 mg/kg intraperitoneal pentobarbital, 100 mg/kg intraperitoneal ketamine or 1.5% isoflurane. Rats had femoral artery cannulas inserted for hemodynamic monitoring and serial arterial blood gas measurements. RESULTS: Observational study: There was a marked reduction in respiratory rate following 4 min of normoxic hypercapnia; average reduction of 9 breaths/min (p < 0.001) (17% reduction from baseline). Interventional study: increasing CO2 caused dose-dependent increase in respiratory rate for ketamine-xylazine (p = 0.007) and isoflurane (p = 0.016) but dose-dependent decrease in respiratory rate for pentobarbital (p = 0.046). Increasing inspired CO2 caused dose-dependent acidosis following pentobarbital and isoflurane (p = 0.013 and p = 0.017, respectively); but not following ketamine-xylazine (p = 0.58). CONCLUSIONS: Inhaled CO2 caused paradoxical dose-dependent bradypnea in animals anesthetized with pentobarbital, an observation not hitherto reported as a part of anesthesia-related respiratory depression.


Assuntos
Anestésicos/farmacologia , Dióxido de Carbono/administração & dosagem , Fármacos Cardiovasculares/administração & dosagem , Isoflurano/farmacologia , Ketamina/farmacologia , Pentobarbital/farmacologia , Taxa Respiratória/efeitos dos fármacos , Acidose Respiratória/sangue , Acidose Respiratória/induzido quimicamente , Administração por Inalação , Animais , Relação Dose-Resposta a Droga , Hemodinâmica/efeitos dos fármacos , Masculino , Camundongos , Ratos Wistar , Respiração/efeitos dos fármacos
15.
Pol J Vet Sci ; 18(1): 217-22, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25928930

RESUMO

UNLABELLED: Apart from the HH equation, the acid-base balance of an organism is also described by the Stewart model, which assumes that the proper insight into the ABB of the organism is given by an analysis of: pCO2, the difference of concentrations of strong cations and anions in the blood serum - SID, and the total concentration of nonvolatile weak acids - Acid total. The notion of an anion gap (AG), or the apparent lack of ions, is closely related to the acid-base balance described according to the HH equation. Its value mainly consists of negatively charged proteins, phosphates, and sulphates in blood. In the human medicine, a modified anion gap is used, which, including the concentration of the protein buffer of blood, is, in fact, the combination of the apparent lack of ions derived from the classic model and the Stewart model. In brachycephalic dogs, respiratory acidosis often occurs, which is caused by an overgrowth of the soft palate, making it impossible for a free air flow and causing an increase in pCO2--carbonic acid anhydride The aim of the present paper was an attempt to answer the question whether, in the case of systemic respiratory acidosis, changes in the concentration of buffering ions can also be seen. The study was carried out on 60 adult dogs of boxer breed in which, on the basis of the results of endoscopic examination, a strong overgrowth of the soft palate requiring a surgical correction was found. For each dog, the value of the anion gap before and after the palate correction procedure was calculated according to the following equation: AG = ([Na+ mmol/l] + [K+ mmol/l])--([Cl- mmol/l]+ [HCO3- mmol/l]) as well as the value of the modified AG--according to the following equation: AGm = calculated AG + 2.5 x (albumins(r)--albumins(d)). The values of AG calculated for the dogs before and after the procedure fell within the limits of the reference values and did not differ significantly whereas the values of AGm calculated for the dogs before and after the procedure differed from each other significantly. CONCLUSIONS: 1) On the basis of the values of AGm obtained it should be stated that in spite of finding respiratory acidosis in the examined dogs, changes in ion concentration can also be seen, which, according to the Stewart theory, compensate metabolic ABB disorders 2) In spite of the fact that all the values used for calculation of AGm were within the limits of reference values, the values of AGm in dogs before and after the soft palate correction procedure differed from each other significantly, which proves high sensitivity and usefulness of the AGm calculation as a diagnostic method.


Assuntos
Equilíbrio Ácido-Base , Acidose Respiratória/veterinária , Doenças do Cão/diagnóstico , Acidose Respiratória/sangue , Acidose Respiratória/diagnóstico , Animais , Doenças do Cão/sangue , Cães , Feminino , Masculino , Modelos Biológicos
17.
Respir Care ; 59(12): 1825-31, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25140033

RESUMO

BACKGROUND: Open mouthpiece ventilation is efficacious in patients with neuromuscular disease. We used this ventilation technique in patients with exacerbations of COPD with mild to moderate acidosis. METHODS: The study was performed in 2 respiratory monitoring care units. Fifty subjects with exacerbations of COPD, breathing frequency > 25, PaCO2 > 45, and pH between 7.25 and 7.30, as well as Kelly scale ≤ 2 were enrolled. Subjects were randomly assigned to receive noninvasive ventilation (NIV) via nasal mask or mouthpiece ventilation. The primary outcome was improvement in arterial blood gases. Arterial blood gases and breathing frequency were recorded 2 h after the start of the enrollment and then after 12, 24, and 48 h. The duration of NIV, hospital stay, and acceptability of the interface (mouthpiece or nasal mask) using a Likert scale were assessed. RESULTS: No subjects had deterioration of gas exchange. The 2 groups had similar trends in arterial blood gases and breathing frequency. No differences in duration of NIV or hospital stay were noted. However, a significant difference in acceptability was found: subjects preferred mouthpiece ventilation (P < .01). CONCLUSIONS: Open mouthpiece ventilation is a useful technique and may prevent further deterioration of gas exchange in COPD patients with mild to moderate acidosis (similar to traditional NIV delivered by a nasal mask). www.chictr.org registration ChiCTR-TRC-12002672.


Assuntos
Acidose Respiratória/sangue , Máscaras , Ventilação não Invasiva/instrumentação , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/terapia , Acidose Respiratória/etiologia , Idoso , Gasometria , Progressão da Doença , Feminino , Humanos , Tempo de Internação , Masculino , Satisfação do Paciente , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Troca Gasosa Pulmonar , Taxa Respiratória , Fatores de Tempo
18.
Crit Care ; 18(3): R124, 2014 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-24942014

RESUMO

INTRODUCTION: While non-invasive ventilation aimed at avoiding intubation has become the modality of choice to treat mild to moderate acute respiratory acidosis, many severely acidotic patients (pH <7.20) still need intubation. Extracorporeal veno-venous CO2 removal (ECCO2R) could prove to be an alternative. The present animal study tested in a systematic fashion technical requirements for successful ECCO2R in terms of cannula size, blood and sweep gas flow. METHODS: ECCO2R with a 0.98 m(2) surface oxygenator was performed in six acidotic (pH <7.20) pigs using either a 14.5 French (Fr) or a 19Fr catheter, with sweep gas flow rates of 8 and 16 L/minute, respectively. During each experiment the blood flow was incrementally increased to a maximum of 400 mL/minute (14.5Fr catheter) and 1000 mL/minute (19Fr catheter). RESULTS: Amelioration of severe respiratory acidosis was only feasible when blood flow rates of 750 to 1000 mL/minute (19Fr catheter) were used. Maximal CO2-elimination was 146.1 ± 22.6 mL/minute, while pH increased from 7.13 ± 0.08 to 7.41 ± 0.07 (blood flow of 1000 mL/minute; sweep gas flow 16 L/minute). Accordingly, a sweep gas flow of 8 L/minute resulted in a maximal CO2-elimination rate of 138.0 ± 16.9 mL/minute. The 14.5Fr catheter allowed a maximum CO2 elimination rate of 77.9 mL/minute, which did not result in the normalization of pH. CONCLUSIONS: Veno-venous ECCO2R may serve as a treatment option for severe respiratory acidosis. In this porcine model, ECCO2R was most effective when using blood flow rates ranging between 750 and 1000 mL/minute, while an increase in sweep gas flow from 8 to 16 L/minute had less impact on ECCO2R in this setting.


Assuntos
Acidose Respiratória/terapia , Dióxido de Carbono/sangue , Circulação Extracorpórea/métodos , Acidose Respiratória/sangue , Animais , Gasometria , Modelos Animais de Doenças , Concentração de Íons de Hidrogênio , Pressão Parcial , Suínos
19.
COPD ; 11(6): 645-51, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24945887

RESUMO

Non-invasive ventilation (NIV) is an evidence based management of acidotic, hypercapnic exacerbations of COPD. Previous national and international audits of clinical practice have shown variation against guideline standards with significant delays in initiating NIV. We aimed to map the clinical pathway to better understand delays and reduce the door-to-NIV time to less than 3 hours for all patients with acidotic, hypercapnic exacerbations of COPD requiring this intervention, by mandating the use of a guideline based educational management proforma.The proforma was introduced at 7 acute hospitals in North London and Essex and initiated at admission of the patient. It was used to record the clinical pathway and patient outcomes until the point of discharge or death. Data for 138 patients were collected. 48% of patients commenced NIV within 3 hours with no reduction in door-to-mask time during the study period. Delays in starting NIV were due to: time taken for review by the medical team (101 minutes) and time taken for NIV to be started once a decision had been made (49 minutes). There were significant differences in door-to-NIV decision and mask times between differing respiratory on-call systems, p < 0.05). The introduction of the proforma had no effect on door-to-mask times over the study period. Main reasons for delay were related to timely access to medical staff and to NIV equipment; however, a marked variation in practice within these hospitals was been noted, with a 9-5 respiratory on-call system associated with shorter NIV initiation times.


Assuntos
Procedimentos Clínicos , Ventilação não Invasiva , Doença Pulmonar Obstrutiva Crônica/terapia , Melhoria de Qualidade , Tempo para o Tratamento/normas , Acidose Respiratória/sangue , Acidose Respiratória/etiologia , Idoso , Idoso de 80 Anos ou mais , Gasometria , Tomada de Decisões , Progressão da Doença , Inglaterra , Feminino , Hospitais/normas , Humanos , Hipercapnia/etiologia , Masculino , Auditoria Médica/métodos , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/complicações , Resultado do Tratamento
20.
Respir Care ; 59(2): 252-62, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23821762

RESUMO

BACKGROUND: Patients with COPD have reduced exercise tolerance associated with dyspnea. This exercise intolerance is primarily due to impaired ventilatory mechanics, but it is also associated with a combination of factors, including inefficient gas exchange, lactic acidosis at a low work rate, and exercise-induced hypoxemia. The survival prognosis of COPD patients with severely reduced exercise capacity is extremely poor, but the pathophysiology of these patients during exercise remains to be accurately established. The present study aimed to characterize life-threatening factors such as hypoxemia, acidosis, and sympathetic activation during exercise in these patients. METHODS: We monitored changes in life-threatening factors and compared these factors among quartile groups, defined according to their peak oxygen uptake status. Ninety-one COPD subjects (82 males, 9 females, average age 69.7 ± 6.8 y) consecutively underwent incremental cardiopulmonary exercise testing using a cycle ergometer. Arterial blood gases, lactate, and catecholamines were measured during cardiopulmonary exercise testing. RESULTS: The pathophysiology of the COPD differed among the 4 subject groups. Subjects with the most severely reduced exercise capacity (peak oxygen uptake ≤ 623 mL/min) were characterized by exercise-induced steep decrease in PaO2 slope (-78 ± 70 mm Hg/L/min), rapid progression of respiratory acidosis, little change in lactic acidosis, and sympathetic activation at low-intensity work load (plasma norepinephrine 1.41 ± 0.94 ng/mL at 20 watts work load), in addition to the limitation of increase in ventilation and impaired gas exchange. CONCLUSIONS: The mechanisms of exercise intolerance in COPD patients significantly differed among subjects with different exercise capacities. Subjects with the most severely reduced exercise capacity had the characteristics of exercise-induced hypoxemia, sympathetic overactivity, and progressive respiratory acidosis at low-intensity exercise. These life-threatening pathophysiological conditions could be improved by medication and/or pulmonary rehabilitation.


Assuntos
Teste de Esforço , Tolerância ao Exercício/fisiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Acidose Respiratória/sangue , Idoso , Dispneia/fisiopatologia , Teste de Esforço/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Consumo de Oxigênio/fisiologia , Doença Pulmonar Obstrutiva Crônica/sangue , Testes de Função Respiratória , Índice de Gravidade de Doença , Volume de Ventilação Pulmonar/fisiologia
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