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1.
Drugs R D ; 23(4): 339-362, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37938531

RESUMO

Buprenorphine has become an important medication in the context of the ongoing opioid epidemic. However, complex pharmacologic properties and varying government regulations create barriers to its use. This narrative review is intended to facilitate buprenorphine use-including non-traditional initiation methods-by providers ranging from primary care providers to addiction specialists. This article briefly discusses the opioid epidemic and the diagnosis and treatment of opioid use disorder (OUD). We then describe the basic and complex pharmacologic properties of buprenorphine, linking these properties to their clinical implications. We guide readers through the process of initiating buprenorphine in patients using full agonist opioids. As there is no single recommended approach for buprenorphine initiation, we discuss the details, advantages, and disadvantages of the standard, low-dose, bridging-strategy, and naloxone-facilitated initiation techniques. We consider the pharmacology of, and evidence base for, buprenorphine in the treatment of pain, in both OUD and non-OUD patients. Throughout, we address the use of buprenorphine in children and adolescent patients, and we finish with considerations related to the settings of pregnancy and breastfeeding.


Assuntos
Buprenorfina , Transtornos Relacionados ao Uso de Opioides , Gravidez , Feminino , Adolescente , Criança , Humanos , Buprenorfina/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Tratamento de Substituição de Opiáceos/métodos , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Analgésicos Opioides/efeitos adversos
4.
Chin Clin Oncol ; 11(2): 14, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35400165

RESUMO

OBJECTIVE: In this review article, we discuss the role of chemotherapy, surgery, and radiation therapy in the treatment of brain metastases from germ cell tumors (GCT). BACKGROUND: GCT rarely metastasize to the brain and there is limited data to guide management. Most instances of brain metastases occur in patients with non-seminomatous germ cell tumors (NSGCT). METHODS: We searched PubMed using the terms 'central nervous system (CNS) metastases' or 'brain metastases' and 'germ cell' from 2011 through August 2021. Review articles and prospective trials related to the treatment of brain metastases in GCT were included in addition to articles obtained by hand search of the references and clinical practice guidelines. CONCLUSIONS: We highlight the importance of using chemotherapy as first-line therapy in most situations. We discuss the very minimal data regarding surgery and its primary role when there is significant mass effect or brain shift. We also compare whole brain radiation therapy (WBRT) with the use of radiosurgery. We then provide overall recommendations based on the reviewed data and our experience as a referral center for GCT.


Assuntos
Neoplasias Encefálicas , Neoplasias Embrionárias de Células Germinativas , Radiocirurgia , Neoplasias Testiculares , Neoplasias Encefálicas/patologia , Irradiação Craniana , Humanos , Masculino , Neoplasias Embrionárias de Células Germinativas/cirurgia , Estudos Prospectivos , Neoplasias Testiculares/cirurgia
8.
Front Psychiatry ; 10: 882, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31866882

RESUMO

Background: Sleep disturbances are a hallmark of posttraumatic stress disorder (PTSD), yet few studies have evaluated the role of dysregulated endogenous melatonin secretion in this condition. Methods: This study compared the sleep quality and nocturnal salivary melatonin profiles of Canadian Armed Forces (CAF) personnel diagnosed with PTSD, using the Clinician Administered PTSD Scale (CAPS score ≥50), with two healthy CAF control groups; comprising, a "light control" (LC) group with standardized evening light exposure and "normal control" (NC) group without light restriction. Participants were monitored for 1-week using wrist actigraphy to assess sleep quality, and 24-h salivary melatonin levels were measured (every 2h) by immunoassay on the penultimate day in a dim-light (< 5 lux) laboratory environment. Results: A repeated measures design showed that mean nocturnal melatonin concentrations for LC were higher than both NC (p = .03) and PTSD (p = .003) with no difference between PTSD and NC. Relative to PTSD, NC had significantly higher melatonin levels over a 4-h period (01 to 05 h), whereas the LC group had higher melatonin levels over an 8-h period (23 to 07 h). Actigraphic sleep quality parameters were not different between healthy controls and PTSD patients, likely due to the use of prescription sleep medications in the PTSD group. Conclusions: These results indicate that PTSD is associated with blunted nocturnal melatonin secretion, which is consistent with previous findings showing lower melatonin after exposure to trauma and suggestive of severe chronodisruption. Future studies targeting the melatonergic system for therapeutic intervention may be beneficial for treatment-resistant PTSD.

9.
World Neurosurg ; 119: e757-e764, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30096494

RESUMO

BACKGROUND: Although stereotactic radiosurgery (SRS) is an effective modality in the treatment of brainstem metastases (BSM), radiation-induced toxicity remains a critical concern. To better understand how severe or life-threatening toxicity is affected by the location of lesions treated in the brainstem, a review of all available studies reporting SRS treatment for BSM was performed. METHODS: Twenty-nine retrospective studies investigating SRS for BSM were reviewed. RESULTS: The rates of grade 3 or greater toxicity, based on the Common Terminology Criteria for Adverse Events, varied from 0 to 9.5% (mean 3.4 ± 2.9%). Overall, the median time to toxicity after SRS was 3 months, with 90% of toxicities occurring before 9 months. A total of 1243 cases had toxicity and location data available. Toxicity rates for lesions located in the medulla were 0.8% (1/131), compared with midbrain and pons, respectively, 2.8% (8/288) and 3.0% (24/811). CONCLUSIONS: Current data suggest that brainstem substructure location does not predict for toxicity and lesion volume within this cohort with median tumor volumes 0.04-2.8 cc does not predict for toxicity.


Assuntos
Neoplasias do Tronco Encefálico/radioterapia , Radiocirurgia/efeitos adversos , Idoso , Neoplasias do Tronco Encefálico/secundário , Feminino , Humanos , Avaliação de Estado de Karnofsky , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Estudos Retrospectivos , Fatores de Tempo
10.
CNS Oncol ; 7(1): 15-23, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29239214

RESUMO

Brainstem metastases offer a unique challenge in cancer treatment, yet stereotactic radiosurgery (SRS) has proven to be an effective modality in treating these tumors. This report discusses the clinical outcomes of patients with brainstem metastases treated at Indiana University with Gamma Knife (GK) radiosurgery from 2008 to 2016. 19 brainstem metastases from 14 patients who had follow-up brain imaging were identified. Median tumor volume was 0.04 cc (range: 0.01-2.0 cc). Median prescribed dose was 17.5 Gy to the 50% isodose line (range: 14-22 Gy). Median survival after GK SRS treatment to brainstem lesion was 17.2 months (range: 2.8-45.6 months). The experience at Indiana University confirms the safety and efficacy of range of GK SRS prescription doses (14-22 Gy) to brainstem metastases.


Assuntos
Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Radiocirurgia , Centros Médicos Acadêmicos , Adulto , Idoso , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Feminino , Seguimentos , Humanos , Indiana , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Radiocirurgia/efeitos adversos , Dosagem Radioterapêutica , Análise de Sobrevida , Resultado do Tratamento , Carga Tumoral , Universidades
12.
Neurosurg Focus ; 38(3): E10, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25727219

RESUMO

Glioblastoma (GBM) is the most common primary brain tumor and carries a grave prognosis. Despite years of research investigating potentially new therapies for GBM, the median survival rate of individuals with this disease has remained fairly stagnant. Delivery of drugs to the tumor site is hampered by various barriers posed by the GBM pathological process and by the complex physiology of the blood-brain and blood-cerebrospinal fluid barriers. These anatomical and physiological barriers serve as a natural protection for the brain and preserve brain homeostasis, but they also have significantly limited the reach of intraparenchymal treatments in patients with GBM. In this article, the authors review the functional capabilities of the physical and physiological barriers that impede chemotherapy for GBM, with a specific focus on the pathological alterations of the blood-brain barrier (BBB) in this disease. They also provide an overview of current and future methods for circumventing these barriers in therapeutic interventions. Although ongoing research has yielded some potential options for future GBM therapies, delivery of chemotherapy medications across the BBB remains elusive and has limited the efficacy of these medications.


Assuntos
Transporte Biológico/fisiologia , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/patologia , Sistemas de Liberação de Medicamentos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/fisiologia , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Humanos
13.
J Neurooncol ; 118(1): 117-22, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24532242

RESUMO

The effectiveness of seizure prophylaxis in controlling postoperative seizures following craniotomy for tumor resection is unclear. Most patients are seizure-free before surgery. To prevent seizures, it is common to treat tumor craniotomy patients postoperatively with an antiepileptic drug (AED). The authors retrospectively analyzed seizure occurrence with and without postoperative prophylactic AEDs. Between 2005 and 2011 at the authors' institution, 588 patients underwent craniotomy for brain tumors and were screened. Data on seizures, AED use, histopathology, comorbidities, complications, and follow-up were collected. Exclusion criteria included lack of follow-up data, previous operation, preoperative seizures, or preoperative AED prophylaxis. The incidence of postoperative seizures in patients with and without prophylactic AEDs was compared using logistic regression analysis. A total of 202 patients (50.5% female) were included. The most common tumor diagnosis was metastasis (42.6%). Of the 202 patients, 66.3% were prescribed prophylactic AED after surgery. Forty-six of 202 (22.8%) suffered a postoperative seizure. The odds of seizure for patients on prophylactic AED was 1.62 times higher than those not on AED (p = 0.2867). No difference was found in seizure occurrence between patients with glioblastoma multiforme compared with other tumor types (odds ratio 1.75, p = 0.1468). No difference was found in time-to-seizure between the two groups (hazard ratio 1.38, p = 0.3776). These data show no statistically significant benefit to prophylactic postoperative AED and a nonsignificant trend for increased seizure risk with AEDs. A randomized, placebo-controlled trial is needed to clarify the benefit of postoperative AED use for brain tumor resection.


Assuntos
Anticonvulsivantes/uso terapêutico , Procedimentos Neurocirúrgicos/efeitos adversos , Complicações Pós-Operatórias/prevenção & controle , Convulsões/etiologia , Convulsões/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Neoplasias Encefálicas/cirurgia , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/fisiopatologia , Estudos Retrospectivos , Adulto Jovem
14.
Psychopharmacology (Berl) ; 214(2): 515-23, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21069516

RESUMO

INTRODUCTION: Melatonin and light treatment are recommended for hastening adaptation to time zone change. We evaluated an afternoon regimen of 3 mg sustained release (SR) melatonin with and without next morning green light treatment for circadian phase advance. Effects of melatonin and light were tested separately and then combined to determine if the total phase change is additive or synergistic. MATERIAL AND METHODS: For each condition (melatonin, placebo, light, melatonin plus light), 11 subjects spent from Tuesday evening until Friday afternoon in the laboratory. For all four conditions, the following sleep schedule was maintained: night 1, 2345 to 0630 hours, night 2, 1600 to 0530 hours, and night 3, 2345 to 0700 hours. For the light-only condition, light treatment was administered between 0700 and 0800 hours on Thursday. For melatonin-only or placebo conditions, capsules were administered at 1600 hours on Wednesday. For the combined condition, melatonin was administered at 1600 hours on Wednesday with light treatment between 0600 and 0700 hours on Thursday. Circadian phase was assessed by calculating dim light melatonin onset (DLMO) from salivary melatonin, using a mean baseline +2 standard deviations (BL+2 SD) threshold. For all four conditions, pre-treatment and post-treatment DLMO assessments were on Tuesday and Thursday evenings, respectively. RESULTS: Phase advances were: melatonin at 1600 hours, 0.72 h p<0.005, light treatment from 0700 to 0800 hours, 0.31 h, non-significant, and the combined treatment, 1.04 h p<0.0002. CONCLUSION: The phase advance from the combination of afternoon melatonin with next morning light is additive.


Assuntos
Relógios Biológicos , Ritmo Circadiano , Síndrome do Jet Lag/prevenção & controle , Melatonina/administração & dosagem , Fototerapia , Viagem , Actigrafia , Adaptação Fisiológica , Administração Oral , Adulto , Análise de Variância , Relógios Biológicos/efeitos dos fármacos , Relógios Biológicos/efeitos da radiação , Cápsulas , Ritmo Circadiano/efeitos dos fármacos , Ritmo Circadiano/efeitos da radiação , Terapia Combinada , Preparações de Ação Retardada , Método Duplo-Cego , Humanos , Síndrome do Jet Lag/etiologia , Síndrome do Jet Lag/metabolismo , Síndrome do Jet Lag/fisiopatologia , Masculino , Melatonina/metabolismo , Pessoa de Meia-Idade , Ontário , Saliva/metabolismo , Sono/efeitos dos fármacos , Sono/efeitos da radiação , Fatores de Tempo
15.
Psychopharmacology (Berl) ; 208(3): 377-86, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20013115

RESUMO

INTRODUCTION: Melatonin is recommended for hastening adaptation to phase shift, but there is little information on appropriate formulations. MATERIALS AND METHODS: We evaluated the efficacy of three melatonin formulations for circadian phase advance and delay: (a) 3 mg regular release (RR), (b) 3 mg sustained release (SR), and (c) 3 mg surge-sustained release (SSR; consisting of 1 mg RR and 2 mg SR). Circadian phase was assessed by salivary melatonin dim light melatonin onset (DLMO) or offset (MelOff) using thresholds of (1) 1.0 pg/ml and (2) mean baseline + 2 standard deviations (BL + 2SD). Subjects spent from Tuesday evenings until Thursday in the laboratory. Melatonin (or placebo) was administered at 1600 hours (phase advance) Wednesday, with DLMO assessment on Tuesday and Thursday and at 0600 hours (phase delay) Wednesday, with DLMO assessment Tuesday, Wednesday, and MelOff Thursday morning. Phase advances using the 1.0 pg/ml DLMO were as follows: placebo, 0.73 h; RR, 1.23 h (p < 0.003); SR, 1.44 h (p < 0.0002); SSR, 1.16 h (p < 0.012), with no difference between formulations. RESULTS AND DISCUSSION: Similar but smaller phase advances were found with BL + 2SD. Using MelOff, posttreatment phase position for the RR formulation was delayed compared to placebo by 1.12 h (p < 0.012), 1.0 pg/ml, and 0.75 h (p < 0.036), BL+2SD. Phase shifts for the SR and SSR conditions could not be determined due to persistent high melatonin levels during sampling times. Similar phase advances were induced by all formulations, and slow clearance of slow release preparations impeded the determination of phase delays. CONCLUSION: Appropriately timed 0.5 mg melatonin doses may avoid these problems.


Assuntos
Relógios Biológicos/efeitos dos fármacos , Ritmo Circadiano/efeitos dos fármacos , Melatonina/farmacologia , Viagem , Adulto , Ritmo Circadiano/fisiologia , Preparações de Ação Retardada , Método Duplo-Cego , Esquema de Medicação , Humanos , Síndrome do Jet Lag/fisiopatologia , Luz , Masculino , Pessoa de Meia-Idade , Saliva/efeitos dos fármacos
16.
Chronobiol Int ; 26(5): 867-90, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19637048

RESUMO

Jet lag degrades performance and operational readiness of recently deployed military personnel and other travelers. The objective of the studies reported here was to determine, using a narrow bandwidth light tower (500 nm), the optimum timing of light treatment to hasten adaptive circadian phase advance and delay. Three counterbalanced treatment order, repeated measures studies were conducted to compare melatonin suppression and phase shift across multiple light treatment timings. In Experiment 1, 14 normal healthy volunteers (8 men/6 women) aged 34.9+/-8.2 yrs (mean+/-SD) underwent light treatment at the following times: A) 06:00 to 07:00 h, B) 05:30 to 07:30 h, and C) 09:00 to 10:00 h (active control). In Experiment 2, 13 normal healthy subjects (7 men/6 women) aged 35.6+/-6.9 yrs, underwent light treatment at each of the following times: A) 06:00 to 07:00 h, B) 07:00 to 08:00 h, C) 08:00 to 09:00 h, and a no-light control session (D) from 07:00 to 08:00 h. In Experiment 3, 10 normal healthy subjects (6 men/4 women) aged 37.0+/-7.7 yrs underwent light treatment at the following times: A) 02:00 to 03:00 h, B) 02:30 to 03:30 h, and C) 03:00 to 04:00 h, with a no-light control (D) from 02:30 to 03:30 h. Dim light melatonin onset (DLMO) was established by two methods: when salivary melatonin levels exceeded a 1.0 pg/ml threshold, and when salivary melatonin levels exceeded three times the 0.9 pg/ml sensitivity of the radioimmunoasssy. Using the 1.0 pg/ml DLMO, significant phase advances were found in Experiment 1 for conditions A (p < .028) and B (p < 0.004). Experiment 2 showed significant phase advances in conditions A (p < 0.018) and B (p < 0.003) but not C (p < 0.23), relative to condition D. In Experiment 3, only condition B (p < 0.035) provided a significant phase delay relative to condition D. Similar but generally smaller phase shifts were found with the 2.7 pg/ml DLMO method. This threshold was used to analyze phase shifts against circadian time of the start of light treatment for all three experiments. The best fit curve applied to these data (R(2) = 0.94) provided a partial phase-response curve with maximum advance at approximately 9-11 h and maximum delay at approximately 5-6 h following DLMO. These data suggest largest phase advances will result when light treatment is started between 06:00 and 08:00 h, and greatest phase delays will result from light treatment started between 02:00 to 03:00 h in entrained subjects with a regular sleep wake cycle (23:00 to 07:00 h).


Assuntos
Síndrome do Jet Lag/terapia , Luz , Fototerapia/métodos , Viagem , Adulto , Relógios Biológicos , Ritmo Circadiano/fisiologia , Feminino , Humanos , Síndrome do Jet Lag/prevenção & controle , Masculino , Melatonina/metabolismo , Pessoa de Meia-Idade , Fotoperíodo , Vigília/fisiologia
17.
Aviat Space Environ Med ; 80(1): 29-59, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19180856

RESUMO

Pilot fatigue is a significant problem in modern aviation operations, largely because of the unpredictable work hours, long duty periods, circadian disruptions, and insufficient sleep that are commonplace in both civilian and military flight operations. The full impact of fatigue is often underappreciated, but many of its deleterious effects have long been known. Compared to people who are well-rested, people who are sleep deprived think and move more slowly, make more mistakes, and have memory difficulties. These negative effects may and do lead to aviation errors and accidents. In the 1930s, flight time limitations, suggested layover durations, and aircrew sleep recommendations were developed in an attempt to mitigate aircrew fatigue. Unfortunately, there have been few changes to aircrew scheduling provisions and flight time limitations since the time they were first introduced, despite evidence that updates are needed. Although the scientific understanding of fatigue, sleep, shift work, and circadian physiology has advanced significantly over the past several decades, current regulations and industry practices have in large part failed to adequately incorporate the new knowledge. Thus, the problem of pilot fatigue has steadily increased along with fatigue-related concerns over air safety. Accident statistics, reports from pilots themselves, and operational flight studies all show that fatigue is a growing concern within aviation operations. This position paper reviews the relevant scientific literature, summarizes applicable U.S. civilian and military flight regulations, evaluates various in-flight and pre-/postflight fatigue countermeasures, and describes emerging technologies for detecting and countering fatigue. Following the discussion of each major issue, position statements address ways to deal with fatigue in specific contexts with the goal of using current scientific knowledge to update policy and provide tools and techniques for improving air safety.


Assuntos
Acidentes Aeronáuticos/prevenção & controle , Medicina Aeroespacial , Fadiga/prevenção & controle , Estimulantes do Sistema Nervoso Central/uso terapêutico , Ritmo Circadiano , Guias como Assunto , Humanos , Hipnóticos e Sedativos/uso terapêutico , Saúde Ocupacional , Descanso , Privação do Sono/prevenção & controle , Análise e Desempenho de Tarefas , Estados Unidos , Vigília , Tolerância ao Trabalho Programado , Carga de Trabalho
18.
Aviat Space Environ Med ; 78(7): 645-52, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17679560

RESUMO

INTRODUCTION: The Canadian Forces has initiated a multiple study project to optimize circadian phase changes using appropriately timed phototherapy and/or ingestion of melatonin for those personnel on long-range deployments and shift workers. The work reported here compared four phototherapeutic devices for efficacy in effecting circadian phase delays. METHODS: In a partially counterbalanced treatment order, 14 subjects (7 men and 7 women), ages 18-51 yr, participated in 5 weekly experimental sessions of phototherapy with 4 different phototherapy devices (light tower, light visor, Litebook, LED spectacles) and a no-phototherapy control. Phototherapy was applied from 24:00 to 02:00 on night. (1) Dim light melatonin onset (DLMO) was assessed on night 1 and night. (2) Subjects were tested for psychomotor performance (serial reaction time, logical reasoning, and serial subtraction tasks) and completed the Stanford Sleepiness Scale on night 1 at 19:00, 23:00, 01:00, 02:00, and 03:00. After phototherapy, subjects completed a phototherapy side-effects questionnaire. RESULTS: All phototherapy devices produced melatonin suppression and significant phase delays. Sleepiness was significantly decreased with the light tower, the light visor, and the Litebook. Task performance was only slightly improved with phototherapy. The LED spectacles and light visor caused greater subjective performance impairment, more difficulty viewing the computer monitor and reading printed text than the light tower or the Litebook. The light visor, the Litebook, and the LED spectacles caused more eye discomfort than the light tower. CONCLUSIONS: The light tower was the best device, producing melatonin suppression and circadian phase change while relatively free of side effects.


Assuntos
Transtornos Cronobiológicos/terapia , Melatonina/análise , Fototerapia/instrumentação , Adolescente , Adulto , Medicina Aeroespacial , Análise de Variância , Fadiga/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Desempenho Psicomotor , Saliva/química , Inquéritos e Questionários , Vigília
19.
Aviat Space Environ Med ; 75(12): 1042-8, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15619858

RESUMO

BACKGROUND: This study compared the distribution of arterial oxygen saturation (SaO2) and susceptibility to Acute Mountain Sickness (AMS) in moderate altitude residents (MAR) and low altitude residents (LAR) following rapid ascent to 4056 m. METHODS: Resting PETCO2 and SaO2 were measured in 38 subjects residing for > 3 mo near Colorado Springs, CO (MAR group), at 1940 m (USAF Academy), and after approximately 1 h at 4056 m on the summit of Pikes Peak, CO, following ascent by car. SaO2 was also measured at 610-m elevation intervals during the ascent. Of the LAR (50 m) group, 39 subjects were exposed to a similar ascent profile in a hypobaric chamber. RESULTS: At 1940 m the MAR SaO2 and PETCO2 were 94 +/- 1% (X +/- SD) and 33.6 +/- 2.8 mmHg, respectively. At 3048 m and higher, MAR SaO2 decreased, reaching 86 +/- 2% (p < 0.001) at 4056 m, and PETCO2 (32.1 +/- 4.5 mmHg) decreased (p < 0.05). At 50 m the LAR SaO2 and PETCO2 were 98 +/- 1% and 38.7 +/- 2.7 mmHg, respectively. At 1940 m and higher, LAR SaO2 decreased (p < 0.001), reaching 82 +/- 5% at 4056 m, and PETCO2 (36.4 +/- 3.5 mmHg) decreased (p < 0.05). Above 2438 m, the MAR SaO2 was higher (p < 0.001) than the LAR. Only one MAR subject, but nine LAR subjects reported AMS symptoms. CONCLUSIONS: Ventilatory acclimatization developed during moderate altitude residence substantially enhances arterial oxygenation during rapid ascents to higher altitudes. Compared with prior studies, the level of ventilatory acclimatization achieved at moderate altitude is similar to residing at 4056 m for approximately 5-9 d.


Assuntos
Adaptação Fisiológica , Doença da Altitude/fisiopatologia , Altitude , Oxigênio/sangue , Respiração , Adolescente , Adulto , Feminino , Humanos , Hipóxia/etiologia , Hipóxia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
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