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Li N, Cheng Y, Jin T, Cao L, Zha J, Zhu X, He Q. Kaempferol and ginsenoside Rg1 ameliorate acute hypobaric hypoxia induced lung injury based on network pharmacology analysis. Toxicol Appl Pharmacol 2023; 480:116742. [PMID: 37923178 DOI: 10.1016/j.taap.2023.116742] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 10/19/2023] [Accepted: 10/29/2023] [Indexed: 11/07/2023]
Abstract
Acute hypobaric hypoxia at high altitude can cause fatal non-cardiogenic high altitude pulmonary edema. Anti-inflammatory and anti-oxidant treatments appear to be a prospective way to alleviate acute hypoxia lung injury. Kaempferol (KA) and ginsenoside Rg1 (GRg1) can be isolated and purified from ginseng with anti-inflammatory, antioxidant, anti-carcinogenic, neuroprotective, and antiaging effects. However, their effects and pharmacological mechanisms on lung injury remains unclear. Network pharmacology analyses were used to explore potential targets of KA and GRg1 against acute hypobaric hypoxia induced lung injury. Rat lung tissues were further used for animal experiment verification. Among the putative targets of KA and GRg1 for inhibition of acute hypobaric hypoxia induced lung injury, AKT1, PIK3R1, PTK2, STAT3, HSP90AA1 and AKT2 were recognized as higher interrelated targets. And PI3K-AKT signaling pathway is considered to be the most important and relevant pathway. The rat experimental results showed that KA and GRg1 significantly improved histopathological changes and decreased pulmonary edema in rats with lung injury caused by acute hypobaric hypoxia. The concentrations of IL-6, TNF-α, MDA, SOD and CAT in rats treated with KA and GRg1 were significantly ameliorated. Protein and mRNA levels of PI3K and AKTI were significantly inhibited after KA administration. KA and GRg1 can lower lung water content, improve lung tissue damage, reduce the production of pro-inflammatory cytokines and the oxidative stress level.
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Affiliation(s)
- Na Li
- School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, China
| | - Yuan Cheng
- Department of Intensive Care Medicine, The Third People's Hospital of Chengdu/Affiliated Hospital of Southwest Jiaotong University, Chengdu, China
| | - Tao Jin
- School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, China
| | - Lirui Cao
- Department of Intensive Care Medicine, The Third People's Hospital of Chengdu/Affiliated Hospital of Southwest Jiaotong University, Chengdu, China
| | - Jieyu Zha
- Department of Intensive Care Medicine, The Third People's Hospital of Chengdu/Affiliated Hospital of Southwest Jiaotong University, Chengdu, China
| | - Xiong Zhu
- Department of Critical Care Medicine, Zhuhai People's Hospital, Zhuhai, Guangdong, China
| | - Qing He
- School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, China; Department of Intensive Care Medicine, The Third People's Hospital of Chengdu/Affiliated Hospital of Southwest Jiaotong University, Chengdu, China.
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Shen Z, Huang D, Jia N, Zhao S, Pei C, Wang Y, Wu Y, Wang X, Shi S, Wang F, He Y, Wang Z. Protective effects of Eleutheroside E against high-altitude pulmonary edema by inhibiting NLRP3 inflammasome-mediated pyroptosis. Biomed Pharmacother 2023; 167:115607. [PMID: 37776644 DOI: 10.1016/j.biopha.2023.115607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/13/2023] [Accepted: 09/26/2023] [Indexed: 10/02/2023] Open
Abstract
Eleutheroside E (EE) is a primary active component of Acanthopanax senticosus, which has been reported to inhibit the expression of inflammatory genes, but the underlying mechanisms remain elusive. High-altitude pulmonary edema (HAPE) is a severe complication of high-altitude exposure occurring after ascent above 2500 m. However, effective and safe preventative measures for HAPE still need to be improved. This study aimed to elucidate the preventative potential and underlying mechanism of EE in HAPE. Rat models of HAPE were established through hypobaric hypoxia. Mechanistically, hypobaric hypoxia aggravates oxidative stress and upregulates (pro)-inflammatory cytokines, activating NOD-like receptor protein 3 (NLRP3) inflammasome-mediated pyroptosis, eventually leading to HAPE. EE suppressed NLRP3 inflammasome-mediated pyroptosis by inhibiting the nuclear translocation of nuclear factor kappa-Β (NF-κB), thereby protecting the lung from HAPE. However, nigericin (Nig), an NLRP3 activator, partially abolished the protective effects of EE. These findings suggest EE is a promising agent for preventing HAPE induced by NLRP3 inflammasome-mediated pyroptosis.
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Affiliation(s)
- Zherui Shen
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Demei Huang
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Nan Jia
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Sijing Zhao
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Caixia Pei
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Yilan Wang
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Yongcan Wu
- Chongqing Medical University, Chongqing 400016, China
| | - Xiaomin Wang
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Shihua Shi
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Fei Wang
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China.
| | - Yacong He
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China; State Key Laboratory of Southwestern Chinese Medicine Resources School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
| | - Zhenxing Wang
- Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China.
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Jones JG. The Hypoxia Hilton: Recollections of a Visit, with a Postscript by JW Severinghaus on Mechanisms of Acute Mountain Sickness. J R Soc Med 2017. [DOI: 10.1177/014107680209501208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- J G Jones
- Woodlands, Rufforth, York YO2 3QF, UK
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Basnyat B. High altitude cerebral and pulmonary edema. Travel Med Infect Dis 2005; 3:199-211. [PMID: 17292039 DOI: 10.1016/j.tmaid.2004.06.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2004] [Accepted: 06/17/2004] [Indexed: 11/17/2022]
Abstract
Altitude illness, which comprises of acute mountain sickness (AMS) and its life threatening complications, high altitude cerebral edema (HACE) and high altitude pulmonary edema (HAPE) is now a well recognized disease process. AMS and HACE are generally thought to be a continuum. Some historical facts about the illness, its new intriguing pathophysiological processes, and clinical picture are discussed here. Although the review deals with both HACE and HAPE, HAPE is covered in greater detail due to the recent important findings related to its pathophysiology and prevention mechanisms. Relevant clinical correlation, the differential diagnosis of altitude sickness for a more sophisticated approach to the disease phenomenon, the possibility of dehydration being a risk factor for altitude sickness, the hypothetical role of angiogenesis in cerebral edema, and the emphasis on some vulnerable groups at high altitude are some of the other newer material discussed in this review. A clear-cut treatment and basic prevention guidelines are included in two panels, and finally the limited literature on the role of genetic factors on susceptibility to altitude sickness is briefly discussed.
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Affiliation(s)
- Buddha Basnyat
- Nepal International Clinic and Himalayan Rescue Association, Patan Hospital, Lal Durbar, GPO Box: 3596, Kathmandu, Nepal
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High Altitude and its Illness: Reply. Med J Armed Forces India 2005; 61:307-8. [DOI: 10.1016/s0377-1237(05)80199-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Abstract
High-altitude illness is the collective term for acute mountain sickness (AMS), high-altitude cerebral oedema (HACE), and high-altitude pulmonary oedema (HAPE). The pathophysiology of these syndromes is not completely understood, although studies have substantially contributed to the current understanding of several areas. These areas include the role and potential mechanisms of brain swelling in AMS and HACE, mechanisms accounting for exaggerated pulmonary hypertension in HAPE, and the role of inflammation and alveolar-fluid clearance in HAPE. Only limited information is available about the genetic basis of high-altitude illness, and no clear associations between gene polymorphisms and susceptibility have been discovered. Gradual ascent will always be the best strategy for preventing high-altitude illness, although chemoprophylaxis may be useful in some situations. Despite investigation of other agents, acetazolamide remains the preferred drug for preventing AMS. The next few years are likely to see many advances in the understanding of the causes and management of high-altitude illness.
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Hanaoka M, Droma Y, Naramoto A, Honda T, Kobayashi T, Kubo K. Vascular endothelial growth factor in patients with high-altitude pulmonary edema. J Appl Physiol (1985) 2003; 94:1836-40. [PMID: 12524373 DOI: 10.1152/japplphysiol.00575.2002] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To examine the role of VEGF in the pathogenesis of high-altitude pulmonary edema (HAPE), we measured the concentrations of VEGF in venous serum and bronchoalveolar lavage fluid in patients with HAPE and in healthy volunteers. The VEGF in venous serum of the patients was normal at admission and significantly increased at recovery. Similarly, the VEGF in bronchoalveolar lavage fluid of the patients was increased at recovery compared with admission, but values at both admission and recovery were significantly lower than those of the controls. The present finding suggests that VEGF probably is destroyed in the lung of HAPE, and it appears less likely to have a critical part in the pathogenesis of HAPE but has rather an important role in the repair process for the impaired cell layer.
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Affiliation(s)
- Masayuki Hanaoka
- First Department of Medicine, Shinshu University School of Medicine, Matsumoto 390-8621, Japan.
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Hornbein TF. A Tribute to John Wendell Severinghaus. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 543:1-6. [PMID: 14713110 DOI: 10.1007/978-1-4419-8997-0_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thomas F Hornbein
- Department of Anesthesiology, University Washington School Medicine Seattle, USA.
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Jones JG. The Hypoxia Hilton: recollections of a visit, with a postscript by J W Severinghaus on mechanisms of acute mountain sickness. J R Soc Med 2002; 95:606-8. [PMID: 12461148 PMCID: PMC1279288 DOI: 10.1258/jrsm.95.12.606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- J G Jones
- Woodlands, Rufforth, York YO2 3QF, UK.
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Broccard AF, Vannay C, Feihl F, Schaller MD. Impact of low pulmonary vascular pressure on ventilator-induced lung injury. Crit Care Med 2002; 30:2183-90. [PMID: 12394942 DOI: 10.1097/00003246-200210000-00002] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To study the impact of low pulmonary vascular pressure on ventilator-induced lung injury. DESIGN Randomized prospective animal study. SUBJECTS Isolated perfused rabbit heart-lung preparation. SETTINGS Animal research laboratory in a university hospital. INTERVENTIONS Twenty isolated sets of normal lungs were perfused (constant flow, 0.3 L/min; left atrial pressure, 6 mm Hg), ventilated for 20 min (pressure control ventilation, 15 cm H2O; baseline period), and then randomized into three groups. Group A (control, n = 7) was perfused and ventilated as previously described during three consecutive 20-min periods. In group B (high airway pressure/normal left atrial pressure, n = 7), pressure control ventilation was 20, 25, and 30 cm H2O during each period. Group C (high airway pressure/low left atrial pressure, n = 6) was ventilated as group B but, in contrast to groups A and B, left atrial pressure was reduced to 1 mm Hg. MEASUREMENTS AND MAIN RESULTS The rate of edema formation (WGR, weight gain per minute normalized for initial lung weight) and the ultrafiltration coefficient (Kf) were measured during and after each period and their changes from baseline [DeltaWGR (edema formation index) and DeltaKf (vascular permeability index)] calculated to compare groups. The incidence and timing of vascular failure were compared. Vascular failure was considered to be present if all the following conditions were met: pulmonary hypertension, accelerated weight gain, and occurrence of fluid leak from the lungs. At the end of the study, DeltaWGR (g.g.min(-1)) was higher in group C (0.54 +/- 0.17) than in groups B (0.08 +/- 0.04) and A (0.00 +/- 0.01; p<.05), as well as in group B compared with A (p <.05). Similar differences between groups (p <.05) were found for DeltaK (g x min(-1) x cm H2O(-1) x 100 g(-1)): C, 7.24 +/- 2.36; B, 1.40 +/- 0.49; A, 0.01 +/- 0.03. Vascular failure was not observed in groups A and B but occurred in all but one preparation in group C (p <.05; C vs. A and B). CONCLUSION Reducing left atrial pressure results in more severe ventilator-induced lung injury. These results suggest that lung blood volume modulates cyclic tidal lung stress.
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Affiliation(s)
- Alain F Broccard
- Division of Intensive Care, Department of Medicine, University Hospital, Lausanne, Switzerland
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Platoshyn O, Yu Y, Golovina VA, McDaniel SS, Krick S, Li L, Wang JY, Rubin LJ, Yuan JX. Chronic hypoxia decreases K(V) channel expression and function in pulmonary artery myocytes. Am J Physiol Lung Cell Mol Physiol 2001; 280:L801-12. [PMID: 11238022 DOI: 10.1152/ajplung.2001.280.4.l801] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activity of voltage-gated K+ (KV) channels regulates membrane potential (E(m)) and cytosolic free Ca2+ concentration ([Ca2+](cyt)). A rise in ([Ca2+](cyt))in pulmonary artery (PA) smooth muscle cells (SMCs) triggers pulmonary vasoconstriction and stimulates PASMC proliferation. Chronic hypoxia (PO(2) 30-35 mmHg for 60-72 h) decreased mRNA expression of KV channel alpha-subunits (Kv1.1, Kv1.5, Kv2.1, Kv4.3, and Kv9.3) in PASMCs but not in mesenteric artery (MA) SMCs. Consistently, chronic hypoxia attenuated protein expression of Kv1.1, Kv1.5, and Kv2.1; reduced KV current [I(KV)]; caused E(m) depolarization; and increased ([Ca2+](cyt)) in PASMCs but negligibly affected KV channel expression, increased I(KV), and induced hyperpolarization in MASMCs. These results demonstrate that chronic hypoxia selectively downregulates KV channel expression, reduces I(KV), and induces E(m) depolarization in PASMCs. The subsequent rise in ([Ca2+](cyt)) plays a critical role in the development of pulmonary vasoconstriction and medial hypertrophy. The divergent effects of hypoxia on KV channel alpha-subunit mRNA expression in PASMCs and MASMCs may result from different mechanisms involved in the regulation of KV channel gene expression.
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Affiliation(s)
- O Platoshyn
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, UCSD Medical Center, 200 W. Arbor Dr., San Diego, CA 92103-8382, USA
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Serrano-Dueñas M. [Acute mountain sickness: the clinical characteristics of a cohort of 615 patients]. Med Clin (Barc) 2000; 115:441-5. [PMID: 11093854 DOI: 10.1016/s0025-7753(00)71587-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To study the acute mountain sickness (AMS) and the influence the altitude has on individuals according to time of exposure, age and place of residence. Study cohort prospective in the shelters of Cotopaxi and Chimborazo (4,800 and 5,000 m), in the Ecuatorian Andes. SUBJECTS AND METHODS Tourists from 8 to 51 years of age, residents of the coastal and mountain regions, exposed suddenly to the altitude. Signs and symptoms were recorded at 2, 8, 20 and 24 h of exposure and categorized according to the degree of acute mountain sickness found: AMS 1 [4 to 7 points (light), AMS 2 [8 to 11 points (moderate)] and AMS 3 [more than 12 points (severe)]. RESULTS The study, consisted of 615 patients, was completed by 564. Neurological symptoms are prevalent (headache in the 81.7% of patients) over cardiopulmonary symptoms (cardiac frequency over 100/min in the 25.6%). At 20 h (after one night), the signs and symptoms are more intense and affect a greater number of people (p < 0.0001). Patients from 8 to 22 years of age and residents of the coast have a greater risk of developing AMS 2 (p < 0.01). Overweight, a sedentary life style and a previous incidence of altitude sickness are factors which contribute to the development of AMS 2 (p < 0.001). CONCLUSIONS AMS is an important neurological affection. Young people, individuals from sea-level, as well as those whose are overweight, sedentary or who have previously experienced AMS, have a higher risk of developing AMS 2 after a sudden exposure to altitudes between 4,800 and 5,000 meters. Lack of balance and coordination, and shortness of breath at rest imply AMS 3 and the presence of high altitude cerebral or pulmonary edema.
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Affiliation(s)
- M Serrano-Dueñas
- Servicio de Neurología. Hospital Carlos Andrade Marín. Instituto Ecuatoriano de Seguridad Social. Facultad de Medicina. Pontificia Universidad Católica de Ecuador, Quito.
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Hanaoka M, Tanaka M, Ge RL, Droma Y, Ito A, Miyahara T, Koizumi T, Fujimoto K, Fujii T, Kobayashi T, Kubo K. Hypoxia-induced pulmonary blood redistribution in subjects with a history of high-altitude pulmonary edema. Circulation 2000; 101:1418-22. [PMID: 10736286 DOI: 10.1161/01.cir.101.12.1418] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pulmonary hypertension has been suggested to play an important role in development of high-altitude pulmonary edema (HAPE), and individual susceptibility has been suggested to be associated with enhanced pulmonary vascular response to hypoxia. We hypothesized that much greater pulmonary vasoconstriction would be induced by acute alveolar hypoxia in HAPE-susceptible (HAPE-s) subjects and that changes in pulmonary blood flow distribution could be demonstrated by radionuclide study. METHODS AND RESULTS We performed ventilation-perfusion scintigraphy in 8 HAPE-s subjects and 5 control subjects while each was in the supine position and acquired functional images of pulmonary blood flow and ventilation under separate normoxic and hypoxic (arterial oxygen saturation, 70%) conditions. We also measured acceleration time/right ventricular ejection time (AcT/RVET) with Doppler echocardiography under each condition in both groups. Moreover, we assayed human leukocyte antigen (HLA) alleles serologically in the HAPE-s group. Pulmonary blood flow was significantly shifted from the basal lung region to the apical lung region under hypoxia in HAPE-s subjects, although no significant change in regional ventilation was observed. With Doppler echocardiography, HAPE-s subjects showed increased pulmonary arterial pressure during hypoxia compared with control subjects. The magnitude of cephalad redistribution of lung blood flow was significantly higher in the HLA-DR6-positive than in HLA-DR6-negative HAPE-s subjects. CONCLUSIONS These findings suggest that acute hypoxia induces much greater cephalad redistribution of pulmonary blood flow that results from exaggerated vasoconstriction in the basal lung in HAPE-s subjects. Furthermore, pulmonary vascular hyperreactivity to hypoxia may be associated with HLA-DR6.
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Affiliation(s)
- M Hanaoka
- First Department of Medicine, and Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
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Broccard AF, Hotchkiss JR, Suzuki S, Olson D, Marini JJ. Effects of mean airway pressure and tidal excursion on lung injury induced by mechanical ventilation in an isolated perfused rabbit lung model. Crit Care Med 1999; 27:1533-41. [PMID: 10470761 DOI: 10.1097/00003246-199908000-00022] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To study the relative contributions of mean airway pressure (mPaw) and tidal excursion (V(T)) to ventilator-induced lung injury under constant perfusion conditions. DESIGN Prospective, randomized study. SETTING Experimental animal laboratory. SUBJECTS Fifteen sets of isolated rabbit lungs. INTERVENTIONS Rabbit lungs were perfused (constant flow, 500 mL/min; capillary pressure, 10 mm Hg) and randomized to be ventilated at identical peak transpulmonary pressure (pressure control ventilation [30 cm H2O and frequency of 20/min]) with three different ventilatory patterns that differed from each other by either mPaw or V(T): group A (low mPaw [13.4+/-0.2 cm H2O]/large V(T) [55+/-8 mL], n = 5); group B (high mPaw [21.2+/-0.2 cm H2O]/small V(T) [18+/-1 mL], n = 5); and group C (high mPaw [21.8+/-0.5 cm H2O]/large V(T) [53+/-5 mL], n = 5). MEASUREMENTS AND MAIN RESULTS Continuous weight gain (edema formation), change in ultrafiltration coefficient (deltaKf, vascular permeability index), and histology (lung hemorrhage) were examined. In group A, deltaKf (0.08+/-0.08 g/min/cm H2O/100 g) was less than in group B (0.28+/-0.19 g/min/cm H2O/100 g) or group C (0.41+/-0.29 g/min/cm H2O/100 g) (p = .05). Group A experienced significantly less hemorrhage (histologic score, 5.4+/-2.2) than groups B (10.3+/-2.1) and C (11.1+/-3.0) (p < .05). A similar trend was observed for weight gain. In contrast to tidal excursion, mPaw was found to be a significant factor for lung hemorrhage and increased Kf (two-way analysis of variance; p < .05). Weight gain (r2 = .54, p = .04) and lung hemorrhage (r2 = .65, p = .01) correlated with the mean pulmonary artery pressure changes that resulted from the implementation of the ventilatory strategies. The difference between the changes in mPaw and mean pulmonary artery pressure linearly predicted deltaKf (p = .005 and .05, respectively, r2 = 0.73). CONCLUSIONS Under these experimental conditions, mPaw contributes more than tidal excursion to lung hemorrhage and permeability alterations induced by mechanical ventilation.
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Affiliation(s)
- A F Broccard
- Division of Pulmonary and Critical Care Medicine, University of Minnesota, Minneapolis, USA.
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Severinghaus JW. Uses of high altitude for studies of effects of hypoxia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1999; 454:17-28. [PMID: 9889872 DOI: 10.1007/978-1-4615-4863-8_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- J W Severinghaus
- Department of Anesthesia, University of California, San Francisco, USA
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Abstract
High altitude pulmonary edema. Med. Sci. Sports Exerc., Vol. 31, No. 1 (Suppl.), pp. S23-S27, 1999. Altitude, speed and mode of ascent, and, above all, individual susceptibility are the most important determinants for the occurrence of high altitude pulmonary edema (HAPE). This illness usually occurs only 2-5 d after acute exposure to altitudes above 2500-3000 m. Chest radiographs and CT scans show a patchy predominantly peripheral distribution of edema. Wedge pressure is normal at rest, and there is an excessive rise of pulmonary artery pressure (PAP) that precedes edema formation and appears to be a crucial pathophysiologic factor for HAPE. Additional factors such as an inflammatory response and/or a decreased fluid clearance from the lung may, however, be necessary for the development of this noncardiogenic pulmonary edema. Bronchoalveolar lavage in patients with mostly advanced HAPE shows evidence of inflammatory response with increased permeability. There are, however, no prospective data to decide whether the inflammatory response is a primary cause of HAPE or a consequence of edema formation. Supplemental oxygen is the primary treatment in areas with medical facilities whereas the treatment of choice in remote mountain areas is immediate descent. When this is impossible and supplemental oxygen is not available, treatment with nifedipine is recommended until descent is possible. Even susceptible individuals can avoid HAPE when they ascend slowly with an average gain of altitude not exceeding 300-350 m.d-1 above an altitude of 2500 m.
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Affiliation(s)
- P Bärtsch
- Department of Medicine, Institute of Sports Medicine, Heidelberg, Germany.
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Davis WM, Waters IW. High altitude may be synergistic with pulmonary hazards of appetite control medications fenfluramine and dexfenfluramine. Med Hypotheses 1998; 49:509-12. [PMID: 9466375 DOI: 10.1016/s0306-9877(97)90070-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Clinical observations over the past 15 years incriminated first fenfluramine and recently dexfenfluramine in the provocation of primary pulmonary hypertension. Limited animal toxicology data tend to support this inference. The basis for respiratory pathology of high-altitude pulmonary malfunction, which reaches its maximal level in high-altitude pulmonary edema, evolves from and depends upon the occurrence of pulmonary hypertension. For this reason we hypothesize that high altitude and these two anorexic medications constitute a potentially synergistic combination, of which physicians treating patients for high-altitude illness, as well as those prescribing the drugs, should be aware.
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Affiliation(s)
- W M Davis
- University of Mississippi, University 38677, USA
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Virmani SK. HIGH ALTITUDE PULMONARY OEDEMA - AN EXPERIENCE IN EASTERN HIMALAYA. Med J Armed Forces India 1997; 53:163-168. [PMID: 28769477 DOI: 10.1016/s0377-1237(17)30708-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Three hundred and five cases of high altitude pulmonary oedema (HAPO) hospitalised in eastern Himalayan region have been analyzed. Incidence of HAPO was 5.5 per cent. Eighty per cent cases occurred during latter half of the year. Fifty six per cent of cases belonged to the third decade of life. HAPO cases occurred most commonly between the height of 2740 m to 5960 m. Eighty three per cent cases developed symptoms within 72 hours of induction to high altitude and 65.9 per cent suffered from the illness despite complete acclimatization. Breathlessness, headache and cough were the commonest symptoms. Tachycardia and tachypnoea was present in all cases. Twenty five per cent cases showed various ECG abnormalities. Mortality rate was 0.98 per cent.
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Affiliation(s)
- S K Virmani
- Classified Specialist (Medicine), Military Hospital Dehradun 248003
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Abstract
This article discusses prevention, recognition, and treatment of altitude illnesses, especially acute mountain sickness, high-altitude pulmonary edema, and high-altitude cerebral edema. Physicians advising travelers and trekkers who will be visiting high-altitude areas will find an organized approach to giving pretravel advice. Physicians practicing in or visiting high-altitude areas will find guidelines for diagnosis and treatment. This article also addresses the issue of patients with underlying diseases who wish to travel to high-altitude destinations.
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Affiliation(s)
- K Zafren
- Columbia Alaska Regional Hospital and Providence Alaska Medical Center, Anchorage, USA
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