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Wu M, Shi B. Letter to the article by Oh et al. J Anesth 2024:10.1007/s00540-024-03353-1. [PMID: 38824240 DOI: 10.1007/s00540-024-03353-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Accepted: 05/24/2024] [Indexed: 06/03/2024]
Affiliation(s)
- Mengjun Wu
- Department of Anesthesiology, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China
| | - Bin Shi
- Department of Pain Medicine, Wenjiang District People's Hospital of Chengdu, Wenjiang Hospital of Sichuan Provincial People's Hospital, No 86, Kangtai Street, Chengdu, Sichuan Province, China.
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Podsiadło P, Brožek T, Balik M, Nowak E, Mendrala K, Hymczak H, Dąbrowski W, Miazgowski B, Rutkiewicz A, Burysz M, Witt-Majchrzak A, Jędrzejczak T, Podsiadło R, Darocha T. Predictors of cardiac arrest in severe accidental hypothermia. Am J Emerg Med 2024; 78:145-150. [PMID: 38281374 DOI: 10.1016/j.ajem.2024.01.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 01/15/2024] [Accepted: 01/19/2024] [Indexed: 01/30/2024] Open
Abstract
STUDY OBJECTIVE To indicate predictors of witnessed hypothermic cardiac arrest. METHODS We conducted a retrospective analysis of 182 patients with severe accidental hypothermia (i.e., with core body temperature of ≤28 °C) who presented with preserved spontaneous circulation at first contact with medical services. We divided the study population into two groups: patients who suffered hypothermic cardiac arrest (HCA) at any time between encounter with medical service and restoration of normothermia, and those who did not sustain HCA. The analyzed outcome was the occurrence of cardiac arrest prior to achieving normothermia. Hemodynamic and biochemical parameters were analyzed with regard to their association with the outcome. RESULTS Fifty-two (29%) patients suffered HCA. In a univariable analysis, four variables were significantly associated with the outcome, namely heart rate (p < 0.001), systolic blood pressure (p = 0.03), ventricular arrhythmia (p = 0.001), and arterial oxygen partial pressure (p = 0.002). In the multivariable logistic regression the best model predicting HCA included heart rate, PaO2, and Base Excess (AUROC = 0.78). In prehospital settings, when blood gas analysis is not available, other multivariable model including heart rate and occurrence of ventricular arrhythmia (AUROC = 0.74) can be used. In this study population, threshold values of heart rate of 43/min, temperature-corrected PaO2 of 72 mmHg, and uncorrected PaO2 of 109 mmHg, presented satisfactory sensitivity and specificity for HCA prediction. CONCLUSIONS In patients with severe accidental hypothermia, the occurrence of HCA is associated with a lower heart rate, hypoxemia, ventricular arrhythmia, lower BE, and lower blood pressure. These parameters can be helpful in the early selection of high-risk patients and their allocation to extracorporeal rewarming facilities.
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Affiliation(s)
- Paweł Podsiadło
- Department of Emergency Medicine, Jan Kochanowski University, Kielce, Poland.
| | - Tomáš Brožek
- Department of Anaesthesiology and Intensive Care, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Martin Balik
- Department of Anaesthesiology and Intensive Care, 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Ewelina Nowak
- Institute of Health Sciences, Jan Kochanowski University, Kielce, Poland
| | - Konrad Mendrala
- Department of Anaesthesiology and Intensive Care, Medical University of Silesia, Katowice, Poland
| | - Hubert Hymczak
- Faculty of Medicine and Health Sciences, Andrzej Frycz Modrzewski Kraków University, Kraków, Poland
| | - Wojciech Dąbrowski
- Department of Anaesthesiology and Intensive Care, Medical University of Lublin, Poland
| | - Bartosz Miazgowski
- Emergency Department, University Hospital, Pomeranian Medical University, Szczecin, Poland
| | | | - Marian Burysz
- Departament of Cardiac Surgery, Dr. Władysław Biegański Regional Specialist Hospital, Grudziądz, Poland
| | - Anna Witt-Majchrzak
- Department of Cardiac Surgery Provincial Specialist Hospital, Olsztyn, Poland
| | - Tomasz Jędrzejczak
- Department of Cardiosurgery, Pomeranian Medical University in Szczecin, Poland
| | - Rafał Podsiadło
- Department of Anaesthesiology and Intensive Care, University Hospital, Wrocław, Poland
| | - Tomasz Darocha
- Department of Anaesthesiology and Intensive Care, Medical University of Silesia, Katowice, Poland
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Lakshminrusimha S, Abman SH. Oxygen Targets in Neonatal Pulmonary Hypertension: Individualized, "Precision-Medicine" Approach. Clin Perinatol 2024; 51:77-94. [PMID: 38325948 PMCID: PMC10857735 DOI: 10.1016/j.clp.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Oxygen is a specific pulmonary vasodilator. Hypoxemia causes pulmonary vasoconstriction, and normoxia leads to pulmonary vasodilation. However, hyperoxia does not enhance pulmonary vasodilation but causes oxidative stress. There are no clinical trials evaluating optimal oxygen saturation or Pao2 in pulmonary hypertension. Data from translational studies and case series suggest that oxygen saturation of 90% to 97% or Pao2 between 50 and 80 mm Hg is associated with the lowest pulmonary vascular resistance.
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Affiliation(s)
- Satyan Lakshminrusimha
- Department of Pediatrics, University of California, UC Davis Children's Hospital, 2516 Stockton Boulevard, Sacramento, CA 95817, USA.
| | - Steven H Abman
- Department of Pediatrics, The Pediatric Heart Lung Center, University of Colorado Anschutz Medical Campus, Mail Stop B395, 13123 East 16th Avenue, Aurora, CO 80045, USA
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Gangaram-Panday NH, van Essen T, van Weteringen W, Dremmen MHG, Goos TG, de Jonge RCJ, Reiss IKM. Transcutaneous carbon dioxide monitoring during therapeutic hypothermia for neonatal encephalopathy. Pediatr Res 2022; 92:1724-1730. [PMID: 35352004 DOI: 10.1038/s41390-022-02035-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 03/07/2022] [Accepted: 03/11/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND In neonates with post-asphyxial neonatal encephalopathy, further neuronal damage is prevented with therapeutic hypothermia (TH). In addition, fluctuations in carbon dioxide levels have been associated with poor neurodevelopmental outcome, demanding close monitoring. This study investigated the accuracy and clinical value of transcutaneous carbon dioxide (tcPCO2) monitoring during TH. METHODS In this retrospective cohort study in neonates, agreement between arterial carbon dioxide (PaCO2) values and tcPCO2 measurements during TH was determined. TcPCO2 levels during the first 24 h of hypothermia were tested for an association with ischemic brain injury on magnetic resonance imaging (MRI). RESULTS Thirty-four neonates were included. Agreement (bias (95% limits of agreement)) between tcPCO2 and PaCO2 levels was 3.9 (-12.4-20.2) mm Hg. No relation was found between the body temperature and tcPCO2 levels. TcPCO2 levels differed significantly between patients with considerable and minimal damage on MRI; after 6 h (P = 0.02) and 9 h (P = 0.04). CONCLUSIONS Although tcPCO2 provided a limited estimation of PaCO2, it can be used for trend monitoring during TH. TcPCO2 levels after birth could provide an early indicator of ischemic brain injury. This relation should be investigated in large prospective studies, in which adjustments for confounders can be made. IMPACT Transcutaneous carbon dioxide measurements during therapeutic hypothermia in neonates show limited accuracy similar to measurements reported in normothermic neonates and can be used for trend monitoring. Low transcutaneous carbon dioxide levels during the first 24 h were associated with considerable ischemic brain injury on MRI. The value of transcutaneous carbon dioxide measurements during the first 24 h as an indicator of considerable ischemic brain injury on MRI should be investigated in future studies, adjusting for confounders. Transcutaneous oxygen measurements during therapeutic hypothermia showed an inaccuracy that could not be related to a low body temperature.
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Affiliation(s)
- Norani H Gangaram-Panday
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands.
| | - Tanja van Essen
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Willem van Weteringen
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Pediatric Surgery, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marjolein H G Dremmen
- Department of Radiology and Nuclear Medicine, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Tom G Goos
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands.,Department of Biomechanical Engineering, Faculty of Mechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Rogier C J de Jonge
- Pediatric Intensive Care Unit, Departments of Pediatrics and Pediatric Surgery, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Irwin K M Reiss
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
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Wintermark P, Mohammad K, Bonifacio SL. Proposing a care practice bundle for neonatal encephalopathy during therapeutic hypothermia. Semin Fetal Neonatal Med 2021; 26:101303. [PMID: 34711527 DOI: 10.1016/j.siny.2021.101303] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Neonates with neonatal encephalopathy (NE) often present with multi-organ dysfunction that requires multidisciplinary specialized management. Care of the neonate with NE is thus complex with interaction between the brain and various organ systems. Illness severity during the first days of birth, and not only during the initial hypoxia-ischemia event, is a significant predictor of adverse outcomes in neonates with NE treated with therapeutic hypothermia (TH). We thus propose a care practice bundle dedicated to support the injured neonatal brain that is based on the current best evidence for each organ system. The impact of using such bundle on outcomes in NE remains to be demonstrated.
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Affiliation(s)
- Pia Wintermark
- Department of Pediatrics, Division of Newborn Medicine, Montreal Children's Hospital, McGill University, Montreal, QC, Canada.
| | - Khorshid Mohammad
- Department of Pediatrics, Section of Neonatology, University of Calgary, 28 Oki Drive NW, T3B 6A8, Calgary, AB, Canada.
| | - Sonia L Bonifacio
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, 750 Welch Road, Suite 315, 94304, Palo Alto, CA, USA.
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- Newborn Brain Society, PO Box 200783, Roxbury Crossing, 02120, MA, USA
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El-Dib M, Szakmar E, Chakkarapani E, Aly H. Challenges in respiratory management during therapeutic hypothermia for neonatal encephalopathy. Semin Fetal Neonatal Med 2021; 26:101263. [PMID: 34244080 DOI: 10.1016/j.siny.2021.101263] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Neonatal encephalopathy (NE) is a serious condition with devastating neurological outcomes that can impact oxygenation and ventilation. The currently recommended therapeutic hypothermia (TH) for these infants may also has several respiratory implications. It decreases metabolic rate and oxygen demands; however, it increases oxygen solubility in the blood and impacts its release to peripheral tissue including the brain. Respiratory management of infants treated with TH should aim for minimizing exposure to hypocapnia or hyperoxia. Inspiratory gas should be heated to 37 °C and humidified to prevent airway and alveolar injury. Blood gas values should be corrected to the core temperature during TH and the use of alkaline buffers is discouraged. While mild sedation/analgesia may ameliorate the discomfort related to cooling, paralytic agents/heavy sedation should be used with caution considering their side effects. Finally, the use of caffeine still needs careful investigation in this population.
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Affiliation(s)
- Mohamed El-Dib
- Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., CWN#418, Boston, MA, 02115, USA.
| | - Eniko Szakmar
- Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., CWN#418, Boston, MA, 02115, USA; 1st Department of Pediatrics, Semmelweis University, 54 Bokay St., HU-1083, Budapest, Hungary.
| | - Ela Chakkarapani
- Translational Health Sciences, Bristol Medical School, University of Bristol, Regional Neonatal Intensive Care Unit, St Michael's Hospital University Hospitals Bristol NHS Trust, Southwell Street, Bristol, BS2 8EG, United Kingdom.
| | - Hany Aly
- Department of Neonatology, Cleveland Clinic Children's Hospital, 9500 Euclid Avenue # M31-37 Cleveland, OH, 44195, USA.
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Regiroli G, Loi B, Fortas F, Centorrino R, Mosca F, De Luca D. Effect of inspired gas temperature on lung mechanics and gas exchange in neonates in normothermia or therapeutic hypothermia. Resuscitation 2021; 163:116-123. [PMID: 33895234 DOI: 10.1016/j.resuscitation.2021.04.015] [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: 02/06/2021] [Revised: 03/27/2021] [Accepted: 04/12/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Respiratory critical care guidelines suggest heating the air/oxygen mixture but do not recommend a specific temperature target. We aimed to clarify if the inspired gas temperature influences lung mechanics and gas exchange in intubated patients treated with whole body hypothermia (WBH) or normothermia (NT). METHODS Prospective cohort study enrolling neonates ventilated for perinatal asphyxia resuscitation (no lung disease) or acute hypoxemic respiratory failure. Patients were divided between those ventilated in NT or WBH. Compliance (Cdyn), airway resistances (Raw), oxygenation index (OI), PaO2/FiO2, A-a gradient, a/A ratio, estimated alveolar dead space (VDalv), ventilatory index (VI) and CO2 production (VCO2) were registered at the study beginning (inspired gas at 37°C). Then, gas temperature was decreased (32 °C) and variables were recorded again after 1 and 3 h. Data were analysed with univariate and multivariate repeated measures-ANOVA. RESULTS Cdyn, Raw, OI, PaO2/FiO2, A-a gradient, a/A ratio, VDalv, VI and VCO2 are similar between WBH and NT at any timepoint (between-subjects effect); these results do not change adjusting for the presence of respiratory failure. When this is considered in multivariate ANOVA (within-subjects effect), Cdyn (p = 0.016), Raw (p = 0.034) and VDalv (p < 0.001) were worse in patients with respiratory failure than in those without lung disease. CONCLUSIONS Decreasing the gas temperature from 37 °C to 32 °C for 3 h does not change lung mechanics and gas exchange, neither in neonates with, nor in those without respiratory failure and in those treated in NT or WBH. These findings fill a knowledge gap regarding the effect of inspired gas temperature during WBH: they may inform future respiratory critical care guidelines.
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Affiliation(s)
- Giulia Regiroli
- Division of Pediatrics and Neonatal Critical Care, "A.Béclère" Medical Centre, Paris Saclay University Hospitals, APHP, Paris, France; Neonatal Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
| | - Barbara Loi
- Division of Pediatrics and Neonatal Critical Care, "A.Béclère" Medical Centre, Paris Saclay University Hospitals, APHP, Paris, France
| | - Feriel Fortas
- Division of Pediatrics and Neonatal Critical Care, "A.Béclère" Medical Centre, Paris Saclay University Hospitals, APHP, Paris, France; Physiopathology and Therapeutic Innovation Unit-INSERM U999, Paris Saclay University, Paris, France
| | - Roberta Centorrino
- Division of Pediatrics and Neonatal Critical Care, "A.Béclère" Medical Centre, Paris Saclay University Hospitals, APHP, Paris, France; Physiopathology and Therapeutic Innovation Unit-INSERM U999, Paris Saclay University, Paris, France
| | - Fabio Mosca
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
| | - Daniele De Luca
- Division of Pediatrics and Neonatal Critical Care, "A.Béclère" Medical Centre, Paris Saclay University Hospitals, APHP, Paris, France; Physiopathology and Therapeutic Innovation Unit-INSERM U999, Paris Saclay University, Paris, France.
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Sankaran D, Siefkes H, Ing FF, Lakshminrusimha S, Poulain FR. Critical Congenital Heart Disease Detection in the Screening Era: Do Not Neglect the Examination! AJP Rep 2021; 11:e84-e90. [PMID: 34150354 PMCID: PMC8208842 DOI: 10.1055/s-0041-1727275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/05/2021] [Indexed: 11/08/2022] Open
Abstract
Pulse oximetry oxygen saturation (SpO 2 )-based critical congenital heart disease (CCHD) screening is effective in detection of cyanotic heart lesions. We report a full-term male infant with normal perfusion who had passed the CCHD screening at approximately 24 hours after birth with preductal SpO 2 of 99% and postductal SpO 2 of 97%. Detection of a loud systolic cardiac murmur before discharge led to the diagnosis of pulmonary atresia (PA) with ventricular septal defect (PA-VSD) by echocardiogram. The infant was transferred to a tertiary care center after initiation of prostaglandin E1 (PGE1) therapy. Throughout the initial course, he was breathing comfortably without respiratory distress or desaturations on pulse oximetry. We believe that this is the first documented report of PA missed by CCHD screening. Thorough and serial clinical examinations of the newborn infant proved vital in the timely diagnosis of this critical disease. We review the hemodynamics and the recent literature evaluating utility of CCHD screening in the diagnosis of PA-VSD. Pulse oximetry-based CCHD screening should be considered a tool to enhance CCHD detection with an emphasis on detailed serial physical examinations in newborn infants.
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Affiliation(s)
- Deepika Sankaran
- Division of Neonatology, Department of Pediatrics, University of California, Davis, Sacramento, California
| | - Heather Siefkes
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of California, Davis, Sacramento, California
| | - Frank F Ing
- Division of Pediatric Cardiology, Department of Pediatrics, University of California, Davis, Sacramento, California
| | - Satyan Lakshminrusimha
- Division of Neonatology, Department of Pediatrics, University of California, Davis, Sacramento, California
| | - Francis R Poulain
- Division of Neonatology, Department of Pediatrics, University of California, Davis, Sacramento, California
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El‐Dib M, Munster C, Szakmar E, Inder T, Gunn AJ. Late onset oxygen requirement following neonatal therapeutic hypothermia. Acta Paediatr 2020; 109:2258-2265. [PMID: 32043655 DOI: 10.1111/apa.15222] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 02/05/2020] [Accepted: 02/10/2020] [Indexed: 11/29/2022]
Abstract
AIM To investigate the characteristics of infants with neonatal encephalopathy (NE) receiving therapeutic hypothermia (TH) who developed late onset oxygen requirement during or after rewarming. METHODS Infants were stratified by receiving (a) new onset isolated oxygen requirements during or after rewarming; (b) no respiratory support during hospital stay; and (c) invasive and/or non-invasive respiratory support before or during cooling. RESULTS Of 136 infants treated with TH, 49 (36%) did not require any respiratory support, and 78 (57.4%) received invasive or non-invasive support before or during cooling. Nine infants (6.6%) developed late onset oxygen requirement. The late onset oxygen requirement started at median age of 3.8 days (IQR 3.6-5.2) and ended at median 7.5 days (IQR 5.8-12.7). Total hours of O2 exposure were median 62.0 (IQR 24.4-112.6). Maximum support was low-flow nasal cannula from 100% oxygen source with a flow rate of 40-250 mL/min. Infants in this group had higher Apgar scores, milder metabolic acidosis and no seizures. Three infants had diagnostic investigations without significant findings. CONCLUSION A small percentage of neonates with NE developed late onset oxygen requirement during or after rewarming. Late oxygen requirement was associated with evidence of less severe perinatal hypoxia-ischaemia.
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Affiliation(s)
- Mohamed El‐Dib
- Department of Pediatric Newborn Medicine Brigham and Women's Hospital Harvard Medical School Boston MA USA
| | - Chelsea Munster
- Department of Pediatric Newborn Medicine Brigham and Women's Hospital Harvard Medical School Boston MA USA
| | - Eniko Szakmar
- Department of Pediatric Newborn Medicine Brigham and Women's Hospital Harvard Medical School Boston MA USA
- 1st Department of Pediatrics Semmelweis University Budapest Hungary
| | - Terrie Inder
- Department of Pediatric Newborn Medicine Brigham and Women's Hospital Harvard Medical School Boston MA USA
| | - Alistair J. Gunn
- Department of Physiology School of Medical Sciences University of Auckland Auckland New Zealand
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How Do We Monitor Oxygenation during the Management of PPHN? Alveolar, Arterial, Mixed Venous Oxygen Tension or Peripheral Saturation? CHILDREN-BASEL 2020; 7:children7100180. [PMID: 33066076 PMCID: PMC7600440 DOI: 10.3390/children7100180] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/21/2020] [Accepted: 10/11/2020] [Indexed: 02/01/2023]
Abstract
Oxygen is a pulmonary vasodilator and plays an important role in mediating circulatory transition from fetal to postnatal period. Oxygen tension (PO2) in the alveolus (PAO2) and pulmonary artery (PaO2) are the main factors that influence hypoxic pulmonary vasoconstriction (HPV). Inability to achieve adequate pulmonary vasodilation at birth leads to persistent pulmonary hypertension of the newborn (PPHN). Supplemental oxygen therapy is the mainstay of PPHN management. However, optimal monitoring and targeting of oxygenation to achieve low pulmonary vascular resistance (PVR) and optimizing oxygen delivery to vital organs remains unknown. Noninvasive pulse oximetry measures peripheral saturations (SpO2) and a target range of 91-95% are recommended during acute PPHN management. However, for a given SpO2, there is wide variability in arterial PaO2, especially with variations in hemoglobin type (HbF or HbA due to transfusions), pH and body temperature. This review evaluates the role of alveolar, preductal, postductal, mixed venous PO2, and SpO2 in the management of PPHN. Translational and clinical studies suggest maintaining a PaO2 of 50-80 mmHg decreases PVR and augments pulmonary vasodilator management. Nevertheless, there are no randomized clinical trials evaluating outcomes in PPHN targeting SpO2 or PO2. Also, most critically ill patients have umbilical arterial catheters and postductal PaO2 may not be an accurate assessment of oxygen delivery to vital organs or factors influencing HPV. The mixed venous oxygen tension from umbilical venous catheter blood gas may assess pulmonary arterial PO2 and potentially predict HPV. It is crucial to conduct randomized controlled studies with different PO2/SpO2 target ranges for the management of PPHN and compare outcomes.
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Wedgwood S, Steinhorn RH, Lakshminrusimha S. Optimal oxygenation and role of free radicals in PPHN. Free Radic Biol Med 2019; 142:97-106. [PMID: 30995536 PMCID: PMC6761018 DOI: 10.1016/j.freeradbiomed.2019.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 04/01/2019] [Indexed: 02/07/2023]
Abstract
Effective ventilation of the lungs is essential in mediating pulmonary vasodilation at birth to allow effective gas exchange and an increase in systemic oxygenation. Unsuccessful transition prevents the increase in pulmonary blood flow after birth resulting in hypoxemia and persistent pulmonary hypertension of the newborn (PPHN). Management of neonates with PPHN includes ventilation of the lungs with supplemental oxygen to correct hypoxemia. Optimal oxygenation should meet oxygen demand to the tissues and avoid hypoxic pulmonary vasoconstriction (HPV) while preventing oxidative stress. The optimal target for oxygenation in PPHN is not known. Animal models have demonstrated that PaO2<45 mmHg exacerbates HPV. However, there are no practical methods of assessing oxygen levels associated with oxidant stress. Oxidant stress can be due to free radical generation from underlying lung disease or from free radicals generated by supplemental oxygen. Free radicals act on the nitric oxide pathway reducing cGMP and promoting pulmonary vasoconstriction. Antioxidant therapy improves systemic oxygenation in an animal model of PPHN but there are no clinical trials to support such therapy. Targeting preductal SpO2 between 90 and 97% and PaO2 at 50-80 mmHg appears prudent in PPHN but clinical trials to support this practice are lacking. Preterm infants with PPHN present unique challenges due to lack of antioxidant defenses and functional and structural immaturity of the lungs. This review highlights the need for additional studies to mitigate the impact of oxidative stress in the lung and pulmonary vasculature in PPHN.
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Affiliation(s)
- Stephen Wedgwood
- Department of Pediatrics, UC Davis School of Medicine, Sacramento, CA, USA
| | - Robin H Steinhorn
- Department of Hospitalist Medicine, Children's National Health System, Washington DC, USA
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