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1.
J Zoo Wildl Med ; 51(4): 994-998, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33480580

RESUMO

Ketamine-free, midazolam-based protocols have successfully immobilized cervids in the past but their impact on physiological function has not yet been thoroughly investigated. Six deer received IM dexmedetomidine (30.96 ± 3.06 µg/kg) and midazolam (0.31 ± 0.03 mg/kg). Heart rates (HR), respiratory rates (f ), rectal temperature, mean arterial blood pressure (MAP), and oxygen saturation (SpO2) were recorded 25 min after drug delivery (T25) and every 5 min until T55. An arterial blood sample was collected at T40. Mean HR and temperature significantly decreased throughout sedation, but were maintained above critical values (> 60 beats/ min and 37°C, respectively). Although not statistically different, f clinically decreased during sedation. MAP remained within acceptable ranges (60-80 mmHg) and SpO2 above 95%. Mean PaO2 was normal (>80 mmHg), but a mild hypoxemia was observed on two occasions. Recovery was smooth yet prolonged, as the first head movement, attempt to stand, sternal recumbency, and standing position were recorded within 9.36 ± 3.47, 10.32 ± 1.37, 13.13 ± 2.70, and 15.34 ± 2.57 min after IM atipamezole, respectively. This protocol was effective for short-term procedures in captive brown brocket deer, and appeared to be safe on the basis of arterial blood gases and cardiorespiratory variables.


Assuntos
Cervos , Dexmedetomidina/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Imidazóis/farmacologia , Midazolam/farmacologia , Fenômenos Fisiológicos Respiratórios/efeitos dos fármacos , Antagonistas de Receptores Adrenérgicos alfa 2/administração & dosagem , Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Dióxido de Carbono/sangue , Dexmedetomidina/administração & dosagem , Eletrólitos/sangue , Hipnóticos e Sedativos/administração & dosagem , Hipnóticos e Sedativos/farmacologia , Imidazóis/administração & dosagem , Midazolam/administração & dosagem , Oxigênio/sangue
2.
BMC Surg ; 21(1): 31, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413263

RESUMO

BACKGROUND: It is uncertain whether increases in PaCO2 during surgery lead to an increase in plasma potassium concentration and, if so, by how much. Hyperkalaemia may result in cardiac arrhythmias, muscle weakness or paralysis. The key objectives were to determine whether increases in PaCO2 during laparoscopic surgery induce increases in plasma potassium concentrations and, if so, to determine the magnitude of such changes. METHODS: A retrospective observational study of adult patients undergoing laparoscopic abdominal surgery was perfomed. The independent association between increases in PaCO2 and changes in plasma potassium concentration was assessed by performing arterial blood gases within 15 min of induction of anaesthesia and within 15 min of completion of surgery. RESULTS: 289 patients were studied (mean age of 63.2 years; 176 [60.9%] male, and mean body mass index of 29.3 kg/m2). At the completion of the surgery, PaCO2 had increased by 5.18 mmHg (95% CI 4.27 mmHg to 6.09 mmHg) compared to baseline values (P < 0.001) with an associated increase in potassium concentration of 0.25 mmol/L (95% CI 0.20 mmol/L to 0.31 mmol/L, P < 0.001). On multiple regression analysis, PaCO2 changes significantly predicted immediate changes in plasma potassium concentration and could account for 33.1% of the variance (r2 = 0.331, f(3,259) = 38.915, P < 0.001). For each 10 mmHg increment of PaCO2 the plasma potassium concentration increased by 0.18 mmol/L. CONCLUSION: In patients receiving laparoscopic abdominal surgery, there is an increase in PaCO2 at the end of surgery, which is independently associated with an increase in plasma potassium concentration. However, this effect is small and is mostly influenced by intravenous fluid therapy (Plasma-Lyte 148 solution) and the presence of diabetes. Trial registration Retrospectively registered in the Australian New Zealand Clinical Trials Registry (Trial Number: ACTRN12619000716167).


Assuntos
Dióxido de Carbono/sangue , Laparoscopia/efeitos adversos , Potássio/sangue , Adulto , Idoso , Austrália , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
4.
Rev Mal Respir ; 37(9): 756-765, 2020 Nov.
Artigo em Francês | MEDLINE | ID: mdl-33169687

RESUMO

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality, especially in cases of chronic hypercapnic respiratory failure. Following a prolonged debate, the indication and benefits of noninvasive ventilation (NIV) have been recently established. Although improved ventilation and reduction in hyperinflation appear to underlie the positive effect on NIV in COPD, only a few studies have focused on specific ventilatory algorithms for improving PaCO2. METHODS: The main objective of this study is to analyze the impact of Löwenstein's ventilatory algorithms, supposed to allow a better management of hyperinflation and its consequences on alveolar ventilation and blood gas parameters. This is an interventional study in routine care, prospective, single blind, randomized with cross over. The primary endpoint will be the transcutaneous partial pressure of nocturnal carbon dioxide. Secondary endpoints will be: abnormal respiratory events occurring during nocturnal NIV; the objective quality of sleep via polysomnography; the tolerance of ventilation and the subjective quality of sleep evaluated by auto questionnaires. EXPECTED RESULTS: The results of this study will clarify whether is it necessary to explore more the impact of the ventilatory modes developed by Löwenstein, dedicated to hypercapnic COPD patients, requiring a long-term NIV.


Assuntos
Algoritmos , Hipercapnia/terapia , Ventilação não Invasiva , Doença Pulmonar Obstrutiva Crônica/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Dióxido de Carbono/análise , Dióxido de Carbono/sangue , Estudos Cross-Over , Serviços de Assistência Domiciliar , Humanos , Hipercapnia/complicações , Hipercapnia/patologia , Monitorização Fisiológica/métodos , Monitorização Fisiológica/normas , Ventilação não Invasiva/métodos , Seleção de Pacientes , Polissonografia , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/patologia , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Projetos de Pesquisa , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/patologia , Insuficiência Respiratória/terapia , Tamanho da Amostra , Índice de Gravidade de Doença , Método Simples-Cego , Sono/fisiologia
5.
Br J Haematol ; 191(3): 390-393, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33037620

RESUMO

Critically ill patients with coronavirus disease 2019 (COVID-19) present with hypoxaemia and are mechanically ventilated to support gas exchange. We performed a retrospective, observational study of blood gas analyses (n = 3518) obtained from patients with COVID-19 to investigate changes in haemoglobin oxygen (Hb-O2 ) affinity. Calculated oxygen tension at half-saturation (p50 ) was on average (±SD) 3·3 (3·13) mmHg lower than the normal p50 value (23·4 vs. 26·7 mmHg; P < 0·0001). Compared to an unmatched historic control of patients with other causes of severe respiratory failure, patients with COVID-19 had a significantly higher Hb-O2 affinity (mean [SD] p50 23·4 [3·13] vs. 24·6 [5.4] mmHg; P < 0·0001). We hypothesise that, due to the long disease process, acclimatisation to hypoxaemia could play a role.


Assuntos
Betacoronavirus , Infecções por Coronavirus/sangue , Oxiemoglobinas/metabolismo , Pneumonia Viral/sangue , Adulto , Idoso , Dióxido de Carbono/sangue , Dispneia/sangue , Dispneia/etiologia , Feminino , Humanos , Concentração de Íons de Hidrogênio , Hipóxia/sangue , Hipóxia/etiologia , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Oxigênio/sangue , Pandemias , Pressão Parcial , Estudos Retrospectivos
6.
Anesth Analg ; 131(5): 1566-1572, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33079880

RESUMO

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) patients typically receive either tubeless anesthesia or general endotracheal anesthesia (GETA). Patients receiving propofol-based total intravenous anesthesia (TIVA) are at higher risk of sedation-related adverse events (SRAEs) than patients receiving GETA, primarily due to the need for additional airway maneuvers. The increasing use of non-operating room (OR) anesthesia and the perception of a higher incidence of adverse outcomes in non-OR areas has led to the development of devices to improve safety while maintaining efficiency. The purpose of this study was to evaluate if the LMA Gastro™ could be used as a safe alternative to tubeless anesthesia for successfully completing ERCPs. METHODS: Eligible subjects were identified within the patient population at MD Anderson Cancer Center. Inclusion criteria consisted of adult patients (≥18 years old) scheduled for elective ERCP with TIVA. This was a prospective observational study in which the following data were collected: number of attempts and time to successful supraglottic airway (SGA) placement, vital signs, peripheral oxygen saturation (SpO2), median end-tidal CO2, practitioner satisfaction, and any complications. RESULTS: A total of 30 patients were included in this study. The overall rate of successful SGA placement within 3 attempts was 96.7% (95% confidence interval [CI], 82.8-99.9) or 29/30. The rate of successful ERCP with SGA placement within 3 attempts was 93.3% (95% CI, 77.9-99.2) or 28/30. Both the gastroenterologist and anesthesiologist reported satisfaction with the device in 90% of the cases (in 66.7% of the cases both anesthesiologist and gastroenterologist scored the device a 7/7 for satisfaction). Patients maintained an SpO2 of 95%-100% from induction to discharge, with the exception of 1 patient who had an SpO2 of 93%. The median end-tidal CO2 during the procedure for all patients was 35 mm Hg. Observed aspiration did not occur in any patient. Symptoms of hoarseness (13.3%), mouth soreness (6.7%), sore throat (6.6%), and minor bleeding/cuts/redness/change in taste to the tongue (3.3%) were determined through patient questioning before postanesthesia care unit (PACU) discharge. CONCLUSIONS: Our study suggests that the LMA Gastro might be a safe alternative for ERCP procedures. There was a high level of practitioner satisfaction. Only minor complications, such as hoarseness, mouth or throat soreness, or minor trauma to the tongue were experienced by patients. Similar incidences of complications may occur with GETA and tubeless anesthesia. The procedure was well tolerated by all patients; all patients maintained adequate oxygenation and required only minimal blood pressure support.


Assuntos
Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Máscaras Laríngeas/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Manuseio das Vias Aéreas , Anestesiologistas , Dióxido de Carbono/sangue , Colangiopancreatografia Retrógrada Endoscópica/métodos , Feminino , Gastroenterologistas , Rouquidão/epidemiologia , Rouquidão/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Segurança do Paciente , Faringite/epidemiologia , Faringite/etiologia , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos , Língua/lesões
7.
PLoS One ; 15(9): e0238946, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956397

RESUMO

BACKGROUND: The origin of low frequency cerebral hemodynamic fluctuations (CHF) in the resting state remains unknown. Breath-by breath O2-CO2 exchange ratio (bER) has been reported to correlate with the cerebrovascular response to brief breath hold challenge at the frequency range of 0.008-0.03Hz in healthy adults. bER is defined as the ratio of the change in the partial pressure of oxygen (ΔPO2) to that of carbon dioxide (ΔPCO2) between end inspiration and end expiration. In this study, we aimed to investigate the contribution of respiratory gas exchange (RGE) metrics (bER, ΔPO2 and ΔPCO2) to low frequency CHF during spontaneous breathing. METHODS: Twenty-two healthy adults were included. We used transcranial Doppler sonography to evaluate CHF by measuring the changes in cerebral blood flow velocity (ΔCBFv) in bilateral middle cerebral arteries. The regional CHF were mapped with blood oxygenation level dependent (ΔBOLD) signal changes using functional magnetic resonance imaging. Temporal features and frequency characteristics of RGE metrics during spontaneous breathing were examined, and the simultaneous measurements of RGE metrics and CHF (ΔCBFv and ΔBOLD) were studied for their correlation. RESULTS: We found that the time courses of ΔPO2 and ΔPCO2 were interdependent but not redundant. The oscillations of RGE metrics were coherent with resting state CHF at the frequency range of 0.008-0.03Hz. Both bER and ΔPO2 were superior to ΔPCO2 in association with CHF while CHF could correlate more strongly with bER than with ΔPO2 in some brain regions. Brain regions with the strongest coupling between bER and ΔBOLD overlapped with many areas of default mode network including precuneus and posterior cingulate. CONCLUSION: Although the physiological mechanisms underlying the strong correlation between bER and CHF are unclear, our findings suggest the contribution of bER to low frequency resting state CHF, providing a novel insight of brain-body interaction via CHF and oscillations of RGE metrics.


Assuntos
Circulação Cerebrovascular/fisiologia , Taxa Respiratória/fisiologia , Adulto , Velocidade do Fluxo Sanguíneo/fisiologia , Encéfalo/fisiologia , Dióxido de Carbono/sangue , Feminino , Voluntários Saudáveis , Hemodinâmica/fisiologia , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Artéria Cerebral Média/fisiologia , Oxigênio/sangue , Pressão Parcial , Respiração , Descanso/fisiologia , Ultrassonografia Doppler Transcraniana/métodos , Vasodilatação/fisiologia
9.
PLoS One ; 15(9): e0238224, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881886

RESUMO

OBJECTIVE: We previously showed that MELAS patients have decreased cerebrovascular reactivity (CVR) (p≤ 0.002) and increased cerebral blood flow (CBF) (p<0.0026); changes correlated with disease severity and % mutant mtDNA (inversely for CVR; directly for CBF). We ran a prospective pilot in 3 MELAS sibs (m.3243A>G tRNALeu(UUR)) with variable % mutant blood mtDNA to assess effects of L-Arginine (L-Arg) (single dose and 6-wk steady-state trial) on regional CBF, arterial CVR and neurovascular coupling. METHODS: Patients were studied with 3T MRI using arterial spin labeling (ASL) to measure CBF and changes in % Blood Oxygen Level Dependent (BOLD) signal to changes in arterial partial pressure of CO2 to measure CVR. Task fMRI consisted of an alternating black and white checkerboard to evaluate visual cortex response in MELAS and controls. RESULTS: Following L-Arg, there was restoration of serum Arg (76-230 µM) in MELAS sibs and a trend towards increasing CVR in frontal and corresponding decrease in occipital cortex; CVR was unchanged globally. There was a 29-37% reduction in baseline CBF in one patient following 6 wks of L-Arg. Pre-treatment fMRI activation in response to visual cortex stimulus was markedly decreased in the same patient compared to controls in primary visual striate cortex V1 and extrastriate regions V2 to V5 with a marked increase toward control values following a single dose and 6 wks of L-Arg. CONCLUSION: Proposed "healing" effect may be due to more efficient utilization of energy substrates with increased cellular energy balances and ensuing reduction in signalling pathways that augment flow in the untreated state. CLASSIFICATION OF EVIDENCE: This prospective pilot study provides Class III evidence that oral L-Arginine (100 mg/kg single dose or 100 mg/kg three times daily po X 6 weeks) normalizes resting blood flow from elevated pre-treatment levels in patients with MELAS syndrome, selectively increases their CVR from reduced pre-treatment levels in regions most impaired at the expense of less abnormal regions, and normalizes reduced BOLD fMRI activation in response to visual cortex stimulus. CLINICAL TRIALS.GOV (NIH): NCT01603446.


Assuntos
Arginina/uso terapêutico , Circulação Cerebrovascular/fisiologia , Síndrome MELAS/tratamento farmacológico , Acoplamento Neurovascular/fisiologia , Administração Oral , Adolescente , Arginina/sangue , Arginina/farmacologia , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Dióxido de Carbono/sangue , Circulação Cerebrovascular/efeitos dos fármacos , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Acoplamento Neurovascular/efeitos dos fármacos , Ornitina/sangue , Oxigênio/sangue , Projetos Piloto , Estudos Prospectivos , Resultado do Tratamento , Córtex Visual/efeitos dos fármacos , Adulto Jovem
10.
Br J Anaesth ; 125(5): 672-679, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32863016

RESUMO

BACKGROUND: From a physiological viewpoint, changes in end-tidal carbon dioxide (EtCO2) could be a simple, noninvasive, and inexpensive way to monitor changes in cardiac index. This study aimed to assess the utility of changes in EtCO2 as a marker of fluid responsiveness after volume expansion in the operating room. METHODS: A prospective observational study was conducted in a tertiary university teaching hospital, from August 2018 to February 2019. A total of 109 non-consecutive, mechanically ventilated adults undergoing neurosurgery in the supine position with cardiac output monitors were included. Patients with major respiratory disease, arrhythmia, or heart failure were excluded. Volume expansion with 250 ml of saline 0.9% was performed over 10 min to maximise cardiac output during surgery, according to current guidelines. A positive fluid challenge was defined as an increase in stroke volume index of more than 10% from baseline. Changes in stroke volume index (monitored using pulse contour analysis) and EtCO2 were recorded before and after infusion. RESULTS: A total of 242 fluid challenges in 114 patients were performed, of which 26.9% were positive. Changes in EtCO2 > 1.1% induced by infusions had utility for identifying fluid responsiveness, with a sensitivity of 62.9% (95% confidence interval [CI], 62.5-63.3%) and a specificity of 77.8% (95% CI, 77.6-78.1%). The area under the receiver operating characteristic curve for changes in EtCO2 after volume expansion was 0.683 (95% CI, 0.680-0.686). CONCLUSIONS: Changes in EtCO2 induced by rapid infusion of 250 ml saline 0.9% lacked accuracy for identifying fluid responsiveness in mechanically ventilated patients in the operating room. CLINICAL TRIAL REGISTRATION: NCT03635307.


Assuntos
Volume Sanguíneo , Dióxido de Carbono/sangue , Hidratação/métodos , Idoso , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos , Salas Cirúrgicas , Valor Preditivo dos Testes , Estudos Prospectivos , Respiração Artificial , Volume Sistólico , Decúbito Dorsal
11.
PLoS One ; 15(8): e0237010, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32780739

RESUMO

This study analyzed the physiological adjustments caused by the use of the Elevation training mask® (2.0), an airflow restriction mask (ARM) during continuous exercise. Eighteen physically active participants (12 men and 6 women) were randomized to two protocols: continuous exercise with mask (CE-ARM) and continuous exercise without mask (CE). Exercise consisted of cycling for 20 minutes at 60% of maximum power. Metabolic variables, lactate, and gas concentration were obtained from arterialized blood samples at pre and post exercise. Continuous expired gases and myoelectric activity of the quadriceps were performed at rest and during the test. We observed no reduction in oxygen saturation in CE-ARM, leading to lower pH, higher carbon dioxide, and greater hematocrit (all p <0.05). The expired gas analysis shows that the CE-ARM condition presented higher oxygen uptake and expired carbon dioxide concentrations (p <0.05). The CE-ARM condition also presented lower ventilatory volume, ventilatory frequency, and expired oxygen pressure (p <0.05). No changes in electromyography activity and lactate concentrations were identified. We conclude that using ARM does not induce hypoxia and represents an additional challenge for the control of acid-base balance, and we suggest the use of ARM as being suitable for respiratory muscle training.


Assuntos
Exercício Físico/fisiologia , Consumo de Oxigênio/fisiologia , Ventilação Pulmonar/fisiologia , Adulto , Exercícios Respiratórios/métodos , Dióxido de Carbono/sangue , Teste de Esforço/métodos , Feminino , Voluntários Saudáveis , Humanos , Hipóxia/metabolismo , Pulmão/metabolismo , Masculino , Máscaras , Oxigênio/sangue , Respiração , Testes de Função Respiratória
12.
Crit Care ; 24(1): 490, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32768001

RESUMO

BACKGROUND: With recent advances in technology, patients with acute respiratory distress syndrome (ARDS) and severe acute exacerbations of chronic obstructive pulmonary disease (ae-COPD) could benefit from extracorporeal CO2 removal (ECCO2R). However, current evidence in these indications is limited. A European ECCO2R Expert Round Table Meeting was convened to further explore the potential for this treatment approach. METHODS: A modified Delphi-based method was used to collate European experts' views to better understand how ECCO2R therapy is applied, identify how patients are selected and how treatment decisions are made, as well as to identify any points of consensus. RESULTS: Fourteen participants were selected based on known clinical expertise in critical care and in providing respiratory support with ECCO2R or extracorporeal membrane oxygenation. ARDS was considered the primary indication for ECCO2R therapy (n = 7), while 3 participants considered ae-COPD the primary indication. The group agreed that the primary treatment goal of ECCO2R therapy in patients with ARDS was to apply ultra-protective lung ventilation via managing CO2 levels. Driving pressure (≥ 14 cmH2O) followed by plateau pressure (Pplat; ≥ 25 cmH2O) was considered the most important criteria for ECCO2R initiation. Key treatment targets for patients with ARDS undergoing ECCO2R included pH (> 7.30), respiratory rate (< 25 or < 20 breaths/min), driving pressure (< 14 cmH2O) and Pplat (< 25 cmH2O). In ae-COPD, there was consensus that, in patients at risk of non-invasive ventilation (NIV) failure, no decrease in PaCO2 and no decrease in respiratory rate were key criteria for initiating ECCO2R therapy. Key treatment targets in ae-COPD were patient comfort, pH (> 7.30-7.35), respiratory rate (< 20-25 breaths/min), decrease of PaCO2 (by 10-20%), weaning from NIV, decrease in HCO3- and maintaining haemodynamic stability. Consensus was reached on weaning protocols for both indications. Anticoagulation with intravenous unfractionated heparin was the strategy preferred by the group. CONCLUSIONS: Insights from this group of experienced physicians suggest that ECCO2R therapy may be an effective supportive treatment for adults with ARDS or ae-COPD. Further evidence from randomised clinical trials and/or high-quality prospective studies is needed to better guide decision making.


Assuntos
Dióxido de Carbono/sangue , Circulação Extracorpórea/métodos , Unidades de Terapia Intensiva , Doença Pulmonar Obstrutiva Crônica/terapia , /terapia , Consenso , Técnica Delfos , Europa (Continente) , Humanos
13.
Medicine (Baltimore) ; 99(27): e20986, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32629713

RESUMO

RATIONALE: Cerebral carbon dioxide embolism (CCDE) is a rare cause of stroke and is a recognized life-threatening complication.CCDE may result from direct intravascular CO2 insufflation during surgery. Due to the lack of typical clinical manifestations, the disease is often missed or mistaken for another condition. The clinical signs and symptoms depend on the speed and volume of embolized gas entering the blood and the patient's condition. In particular, patent foramen ovale has been found to be associated, in rare cases, with the intraoperative entry of gas into the arterial system. PATIENT CONCERNS: In this report, we present the case of a 35-year-old woman with kidney cancer who underwent laparoscopic right partial nephrectomy. DIAGNOSIS: After the laparoscopic surgery, the patient was initially diagnosed with acute cerebral infarction. INTERVENTIONS: The patient was treated according to the standard method for treatment of acute cerebrovascular disease. OUTCOMES: Three days after the laparoscopic procedure, the patient gained consciousness, and she was discharged without any neurologic sequelae on postoperative day 12. LESSONS SUBSECTIONS AS PER STYLE: Due to the low incidence and sudden occurrence of CCDE, there is a strong likelihood of missed diagnosis or misdiagnosis, and it is; therefore, important to be aware of the risk. The findings from this report would be highly useful as a reference to clinicians in the future.


Assuntos
Dióxido de Carbono/efeitos adversos , Embolia Aérea/etiologia , Insuflação/efeitos adversos , Embolia Intracraniana/etiologia , Laparoscopia/efeitos adversos , Adulto , Dióxido de Carbono/sangue , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/cirurgia , Feminino , Humanos , Embolia Intracraniana/diagnóstico por imagem , Neoplasias Renais/patologia , Neoplasias Renais/cirurgia , Nefrectomia/efeitos adversos
15.
Am J Physiol Heart Circ Physiol ; 319(1): H22-H31, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32442032

RESUMO

Cerebral blood flow is tightly coupled with local neuronal activation and metabolism, i.e., neurovascular coupling (NVC). Studies suggest a role of sympathetic nervous system in the regulation of cerebral blood flow. However, this is controversial, and the sympathetic regulation of NVC in humans remains unclear. Since impaired NVC has been identified in several chronic diseases associated with a heightened sympathetic activity, we aimed to determine whether reflex-mediated sympathetic activation via lower body negative pressure (LBNP) attenuates NVC in humans. NVC was assessed using a visual stimulation protocol (5 cycles of 30 s eyes closed and 30 s of reading) in 11 healthy participants (aged 24 ± 3 yr). NVC assessments were made under control conditions and during LBNP at -20 and -40 mmHg. Posterior (PCA) and middle (MCA) cerebral artery mean blood velocity (Vmean) and vertebral artery blood flow (VAflow) were simultaneously determined with cardiorespiratory variables. Under control conditions, the visual stimulation evoked a robust increase in PCAVmean (∆18.0 ± 4.5%), a moderate rise in VAflow (∆9.6 ± 4.3%), and a modest increase in MCAVmean (∆3.0 ± 1.9%). The magnitude of NVC response was not affected by mild-to-moderate LBNP (all P > 0.05 for repeated-measures ANOVA). Given the small change that occurred in partial pressure of end-tidal CO2 during LBNP, this hypocapnia condition was matched via voluntary hyperventilation in absence of LBNP in a subgroup of participants (n = 8). The mild hypocapnia during LBNP did not exert a confounding influence on the NVC response. These findings indicate that the NVC is not influenced by LBNP or mild hypocapnia in humans.NEW & NOTEWORTHY Visual stimulation evoked a robust increase in posterior cerebral artery velocity and a modest increase in vertebral artery blood flow, i.e., neurovascular coupling (NVC), which was unaffected by lower body negative pressure (LBNP) in humans. In addition, although LBNP induced a mild hypocapnia, this degree of hypocapnia in the absence of LBNP failed to modify the NVC response.


Assuntos
Artérias Cerebrais/fisiologia , Hemodinâmica , Pressão Negativa da Região Corporal Inferior/efeitos adversos , Sistema Nervoso Simpático/fisiologia , Adulto , Dióxido de Carbono/sangue , Circulação Cerebrovascular , Feminino , Humanos , Pressão Negativa da Região Corporal Inferior/métodos , Masculino , Estimulação Luminosa , Reflexo
17.
J Trauma Acute Care Surg ; 89(2): 344-350, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32301878

RESUMO

BACKGROUND: Transfusion with stored whole blood (WB) is increasingly routine practice to resuscitate bleeding trauma patients. Storage of packed red blood cells (pRBC) results in multiple biochemical, structural, and metabolic changes, referred to as to the storage lesion that may mediate adverse effects associated with transfusion of older RBC units. These include increased hemolysis, oxidative stress, and accelerated scavenging of nitric oxide (NO). Whether similar changes occur to stored WB is unclear and are characterized in this study. METHODS: Ten WB units, in citrate-phosphate-dextrose, were purchased from the American Red Cross and changes in hemolysis (increased free hemoglobin, heme, and microparticles), oxidative stress indexed by redox cycling of peroxiredoxin-2 (Prx-2) and NO-scavenging kinetics were determined at different storage times until expiration. RESULTS: Microparticle number and free hemoglobin, but not heme, increased in a storage time-dependent manner. When normalized to the initial number of RBCs in stored WB units, hemolysis rates were similar to those reported for pRBCs. Prx-2 recycling kinetics were slower at expiration compared with earlier storage times. Rates of NO dioxygenation did not change with storage, but were decreased compared with freshly isolated RBCs. CONCLUSION: Storage of WB results in changes associated with the pRBC storage lesion but not for all parameters tested. The relative rate of hemolysis (indexed by free hemoglobin and microparticles) and oxidative stress was similar to that of pRBCs. However, the absolute level of hemolysis products were lower due to lower hematocrit of stored WB units. The clinical significance of these findings requires further investigation.


Assuntos
Preservação de Sangue/efeitos adversos , Eritrócitos/patologia , Eritrócitos/fisiologia , Preservação de Sangue/métodos , Dióxido de Carbono/sangue , Micropartículas Derivadas de Células/metabolismo , Citratos , Eritrócitos/metabolismo , Glucose , Hemoglobinas/metabolismo , Hemólise , Humanos , Óxido Nítrico/metabolismo , Oxirredução , Estresse Oxidativo , Oxigênio/sangue , Peroxirredoxinas/metabolismo
18.
Proc Natl Acad Sci U S A ; 117(18): 10067-10078, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32321831

RESUMO

Disorders of oxygen transport are commonly attributed to inadequate carrying capacity (anemia) but may also relate to inefficient gas exchange by red blood cells (RBCs), a process that is poorly characterized yet assumed to be rapid. Without direct measurements of gas exchange at the single-cell level, the barriers to O2 transport and their relationship with hematological disorders remain ill defined. We developed a method to track the flow of O2 in individual RBCs by combining ultrarapid solution switching (to manipulate gas tension) with single-cell O2 saturation fluorescence microscopy. O2 unloading from RBCs was considerably slower than previously estimated in acellular hemoglobin solutions, indicating the presence of diffusional barriers in intact cells. Rate-limiting diffusion across cytoplasm was demonstrated by osmotically induced changes to hemoglobin concentration (i.e., diffusive tortuosity) and cell size (i.e., diffusion pathlength) and by comparing wild-type cells with hemoglobin H (HbH) thalassemia (shorter pathlength and reduced tortuosity) and hereditary spherocytosis (HS; expanded pathlength). Analysis of the distribution of O2 unloading rates in HS RBCs identified a subpopulation of spherocytes with greatly impaired gas exchange. Tortuosity imposed by hemoglobin was verified by demonstrating restricted diffusivity of CO2, an acidic gas, from the dissipative spread of photolytically uncaged H+ ions across cytoplasm. Our findings indicate that cytoplasmic diffusion, determined by pathlength and tortuosity, is a major barrier to efficient gas handling by RBCs. Consequently, changes in RBC shape and hemoglobin concentration, which are common manifestations of hematological disorders, can have hitherto unrecognized and clinically significant implications on gas exchange.


Assuntos
Transporte Biológico/genética , Eritrócitos/metabolismo , Gases/sangue , Oxigênio/sangue , Adulto , Idoso , Dióxido de Carbono/sangue , Citoplasma/metabolismo , Feminino , Voluntários Saudáveis , Hemoglobinas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Célula Única
20.
PLoS One ; 15(4): e0227775, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32294102

RESUMO

BACKGROUND: Pulmonary arterial hypertension (PAH) is frequently complicated by sleep disordered breathing (SDB), and previous studies have largely focused on hypoxemic SDB. Even though nocturnal hypercapnia was shown to exacerbate pulmonary hypertension, the clinical significance of nocturnal hypercapnia among PAH patients has been scarcely investigated. METHOD: Seventeen patients with PAH were identified from 246 consecutive patients referred to Kyoto University Hospital for the evaluation of lung transplant registration from January 2010 to December 2017. Included in this study were 13 patients whose nocturnal transcutaneous carbon dioxide partial pressure (PtcCO2) monitoring data were available. Nocturnal hypercapnia was diagnosed according to the guidelines of the American Academy of Sleep Medicine. Associations of nocturnal PtcCO2 measurements with clinical features, the findings of right heart catheterization and pulmonary function parameters were evaluated. RESULTS: Nocturnal hypercapnia was diagnosed in six patients (46.2%), while no patient had daytime hypercapnia. Of note, nocturnal hypercapnia was found for 5 out of 6 patients with idiopathic PAH (83.3%). Mean nocturnal PtcCO2 levels correlated negatively with the percentage of predicted total lung capacity (TLC), and positively with cardiac output and cardiac index. CONCLUSION: Nocturnal hypercapnia was prevalent among advanced PAH patients who were waiting for lung transplantation, and associated with %TLC. Nocturnal hypercapnia was associated with the increase in cardiac output, which might potentially worsen pulmonary hypertension especially during sleep. Further studies are needed to investigate hemodynamics during sleep and to clarify whether nocturnal hypercapnia can be a therapeutic target for PAH patients.


Assuntos
Dióxido de Carbono/sangue , Hipertensão Pulmonar Primária Familiar/complicações , Hipercapnia/epidemiologia , Hipertensão Arterial Pulmonar/complicações , Síndromes da Apneia do Sono/epidemiologia , Adolescente , Adulto , Criança , Hipertensão Pulmonar Primária Familiar/sangue , Hipertensão Pulmonar Primária Familiar/cirurgia , Feminino , Humanos , Hipercapnia/sangue , Hipercapnia/diagnóstico , Hipercapnia/etiologia , Japão/epidemiologia , Transplante de Pulmão , Masculino , Pessoa de Meia-Idade , Polissonografia , Prevalência , Hipertensão Arterial Pulmonar/diagnóstico , Hipertensão Arterial Pulmonar/cirurgia , Estudos Retrospectivos , Índice de Gravidade de Doença , Síndromes da Apneia do Sono/sangue , Síndromes da Apneia do Sono/diagnóstico , Síndromes da Apneia do Sono/etiologia , Listas de Espera , Adulto Jovem
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