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Bakhsheshi MF, Diop M, Morrison LB, St. Lawrence K, Lee TY. Coupling of cerebral blood flow and oxygen consumption during hypothermia in newborn piglets as measured by time-resolved near-infrared spectroscopy: a pilot study. NEUROPHOTONICS 2015; 2:035006. [PMID: 26835481 PMCID: PMC4718069 DOI: 10.1117/1.nph.2.3.035006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/18/2015] [Indexed: 06/05/2023]
Abstract
Hypothermia (HT) is a potent neuroprotective therapy that is now widely used in following neurological emergencies, such as neonatal asphyxia. An important mechanism of HT-induced neuroprotection is attributed to the associated reduction in the cerebral metabolic rate of oxygen ([Formula: see text]). Since cerebral circulation and metabolism are tightly regulated, reduction in [Formula: see text] typically results in decreased cerebral blood flow (CBF); it is only under oxidative stress, e.g., hypoxia-ischemia, that oxygen extraction fraction (OEF) deviates from its basal value, which can lead to cerebral dysfunction. As such, it is critical to measure these key physiological parameters during therapeutic HT. This report investigates a noninvasive method of measuring the coupling of [Formula: see text] and CBF under HT and different anesthetic combinations of propofol/nitrous-oxide ([Formula: see text]) that may be used in clinical practice. Both CBF and [Formula: see text] decreased with decreasing temperature, but the OEF remained unchanged, which indicates a tight coupling of flow and metabolism under different anesthetics and over the mild HT temperature range (38°C to 33°C).
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Affiliation(s)
- Mohammad Fazel Bakhsheshi
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
- Robarts Research Institute, Imaging Research Laboratories, 1151 Richmond Street North, London, Ontario N6A 5B7, Canada
| | - Mamadou Diop
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
- Western University, Department of Medical Biophysics, London, Ontario N6A 5C1, Canada
| | - Laura B. Morrison
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
| | - Keith St. Lawrence
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
- Robarts Research Institute, Imaging Research Laboratories, 1151 Richmond Street North, London, Ontario N6A 5B7, Canada
- Western University, Department of Medical Biophysics, London, Ontario N6A 5C1, Canada
| | - Ting-Yim Lee
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada
- Robarts Research Institute, Imaging Research Laboratories, 1151 Richmond Street North, London, Ontario N6A 5B7, Canada
- Western University, Department of Medical Biophysics, London, Ontario N6A 5C1, Canada
- Western University, Department of Medical Imaging, London, Ontario N6A 5W9, Canada
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Karamzadeh AM, Wong BJF, Crumley RL, Ahuja G. Lasers in pediatric airway surgery: Current and future clinical applications. Lasers Surg Med 2004; 35:128-34. [PMID: 15334616 DOI: 10.1002/lsm.20058] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND AND OBJECTIVES The smaller anatomy and limited access to instrumentation pose a challenge to the pediatric airway surgeon. The enhanced precision and ability to photocoagulate tissue while operating with the laser enhances the surgeon's ability to successfully treat unique pediatric conditions. STUDY DESIGN/MATERIALS AND METHODS A comprehensive literature review was performed using the Medline (1995-2004) database. RESULTS Due to its shallow tissue penetration and thermal effect, the carbon dioxide (CO2) laser is generally considered the laser of choice for pediatric airway applications. The potential for increased scarring and damage to underlying tissue caused by the greater penetration depth and thermal effect of the Nd:YAG and potassium-titanyl-phosphate (KTP) lasers preclude their widespread use in this population. CONCLUSIONS In this review, we will discuss the clinical applications of lasers in pediatric airway surgery, the current state of the art, where the current technology is deficient, and the potential applications of novel laser systems.
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Affiliation(s)
- Amir M Karamzadeh
- Department of Otolaryngology-Head and Neck Surgery, University of California, Irvine Medical Center, Orange, California, USA
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