Anesthetic Requirement Is Increased in Redheads

Background Age and body temperature alter inhalational anesthetic requirement; however, no human genotype is associated with inhalational anesthetic requirement. There is an anecdotal impression that anesthetic requirement is increased in redheads. Furthermore, red hair results from distinct mutations of the melanocortin-1 receptor. Therefore, the authors tested the hypothesis that the requirement for the volatile anesthetic desflurane is greater in natural redheaded than in dark-haired women. Methods The authors studied healthy women with bright red (n = 10) or dark (n = 10) hair. Blood was sampled for subsequent analyses of melanocortin-1 receptor alleles. Anesthesia was induced with sevoflurane and maintained with desflurane randomly set at an end-tidal concentration between 5.5 and 7.5%. After an equilibration period, a noxious electrical stimulation (100 Hz, 70 mA) was transmitted through bilateral intradermal needles. If the volunteer moved in response to stimulation, desflurane was increased by 0.5%; otherwise, it was decreased by 0.5%. This was continued until volunteers "crossed over" from movement to nonmovement (or vice versa) four times. Individual logistic regression curves were used to determine desflurane requirement (P50). Desflurane requirements in the two groups were compared using Mann-Whitney nonparametric two-sample test; P < 0.05 was considered statistically significant. Results The desflurane requirement in redheads (6.2 vol% [95% CI, 5.9-6.5]) was significantly greater than in dark-haired women (5.2 vol% [4.9-5.5]; P = 0.0004). Nine of 10 redheads were either homozygous or compound heterozygotes for mutations on the melanocortin-1 receptor gene. Conclusions Red hair seems to be a distinct phenotype linked to anesthetic requirement in humans that can also be traced to a specific genotype.

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Melanocortin-1-receptor gene and sun sensitivity in individuals without red hair

The Lancet ◽

10.1016/s0140-6736(00)02042-0 ◽

2000 ◽

Vol 355 (9209) ◽

pp. 1072-1073 ◽

Cited By ~ 90

Author(s):

Eugene Healy ◽

Niamh Flannagan ◽

Amanda Ray ◽

Carole Todd ◽

Ian J Jackson ◽

...

Keyword(s):

Receptor Gene ◽

Melanocortin 1 Receptor ◽

Red Hair ◽

Sun Sensitivity

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Sequence polymorphism in the human melanocortin 1 receptor gene as an indicator of the red hair phenotype

Forensic Science International ◽

10.1016/s0379-0738(01)00480-7 ◽

2001 ◽

Vol 122 (2-3) ◽

pp. 124-129 ◽

Cited By ~ 64

Author(s):

Eileen A. Grimes ◽

Penny J. Noake ◽

Lindsey Dixon ◽

Andrew Urquhart

Keyword(s):

Receptor Gene ◽

Sequence Polymorphism ◽

Melanocortin 1 Receptor ◽

Red Hair

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Melanocortin-1 Receptor Gene Variants Determine the Risk of Nonmelanoma Skin Cancer Independently of Fair Skin and Red Hair

The American Journal of Human Genetics ◽

10.1086/319500 ◽

2001 ◽

Vol 68 (4) ◽

pp. 884-894 ◽

Cited By ~ 174

Author(s):

Maarten T. Bastiaens ◽

Jeannet A. C. ter Huurne ◽

Christine Kielich ◽

Nelleke A. Gruis ◽

Rudi G.J. Westendorp ◽

...

Keyword(s):

Skin Cancer ◽

Receptor Gene ◽

Nonmelanoma Skin Cancer ◽

Gene Variants ◽

Melanocortin 1 Receptor ◽

Red Hair ◽

Fair Skin

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Influence of Body Temperature on Bispectral Index-Guided Anesthetic Management in Off-Pump Coronary Artery Bypass Grafting

Journal of Cardiac Critical Care TSS ◽

10.1055/s-0040-1718975 ◽

2020 ◽

Vol 4 (02) ◽

pp. 079-085

Author(s):

Muralidhar Kanchi ◽

Priya Nair ◽

Rudresh Manjunath ◽

Kumar Belani

Keyword(s):

Coronary Artery ◽

Body Temperature ◽

Artery Bypass ◽

Anesthetic Depth ◽

Off Pump ◽

Anesthetic Concentration ◽

The Mean ◽

Anesthetic Requirement ◽

Pump Coronary Artery Bypass ◽

End Tidal

Abstract Background Perioperative hypothermia is not uncommon in surgical patients due to anesthetic-induced inhibition of thermoregulatory mechanisms and exposure of patients to cold environment in the operating rooms. Core temperature reduction up to 35°C is often seen in off-pump coronary artery bypass graft (OP-CABG) surgery. Anesthetic depth can be monitored by using bispectral (BIS) index. The present study was performed to evaluate the influence of mild hypothermia on the anesthetic depth using BIS monitoring and correlation of BIS with end-tidal anesthetic concentration at varying temperatures during OP-CABG. Materials and Methods In a prospective observational study design in a tertiary care teaching hospital, patients who underwent elective OP-CABG under endotracheal general anesthesia, were included in the study. Standard technique of anesthesia was followed. BIS, nasopharyngeal temperature, and end-tidal anesthetic concentration of inhaled isoflurane was recorded every 10 minutes. The BIS was adjusted to between 45 and 50 during surgery. Results There were 40 patients who underwent OP-CABG during the study period. The mean age was 51.2 ± 8.7 years, mean body mass index 29.8 ± 2.2, and mean left ventricular ejection fraction was 55.4 ± 4.2%. Anesthetic requirement as guided by BIS between 45 and 50 correlated linearly with core body temperature (r = 0.999; p < 0.001). The mean decrease in the body temperature at the end of 300 minutes was 2.2°C with a mean decrease in end-tidal anesthetic concentration of 0.29%. The reduction in end-tidal anesthetic concentration per degree decrease in temperature was 0.13%. None of the patients reported intraoperative recall. Conclusion In this study, BIS monitoring was used to guide the delivery concentration of inhaled anesthetic using a targeted range of 45 to 50. BIS monitoring allowed the appropriate reduction of anesthetic dosing requirements in patients undergoing OP-CABG without risk of awareness. There was a significant reduction in anesthetic requirements associated with reduction of core temperature. The routine use of BIS is recommended in OP-CABG to titrate anesthetic requirement during occurrence of hypothermia and facilitate fast-track anesthesia in this patient population.

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Interaction of Isoflurane and Nitrous Oxide Combinations Similar for Median Electroencephalographic Frequency and Clinical Anesthesia

Anesthesiology ◽

10.1097/00000542-199604000-00004 ◽

1996 ◽

Vol 84 (4) ◽

pp. 782-788. ◽

Cited By ~ 18

Author(s):

Heiko Ropcke ◽

Helmut Schwilden

Keyword(s):

Nitrous Oxide ◽

Minimum Alveolar Concentration ◽

Dose Range ◽

Volatile Anesthetic ◽

Oxide Concentration ◽

Anesthetic Requirement ◽

Clinical Anesthesia ◽

Sparing Effect ◽

The Relationship ◽

Nitrous Oxide Concentration

Background The volatile anesthetic sparing effect of nitrous oxide in clinical studies is less than might be expected from the additivity of minimum alveolar concentration values. Other studies identify nonadditive interactions between isoflurane and nitrous oxide. The aim of this study was to quantify the interaction of isoflurane and nitrous oxide at a constant median electroencephalographic frequency. Methods Twenty-five patients were studied during laparotomies. Nitrous oxide was randomly administered in concentrations of 0, 20, 40, 60, and 75 vol%, to ten patients for each nitrous oxide concentration. Isoflurane vaporizer settings were chosen so that the median electroencephalographic frequency was held between 2 and 3 Hz. The relationship between nitrous oxide concentrations and required isoflurane concentrations was examined with the method of isoboles. Results Nitrous oxide linearly decreased the isoflurane requirement. Addition of every 10 vol% of nitrous oxide decreases the isoflurane requirement by approximately 0.04 vol%. The total anesthetic requirement of isoflurane and nitrous oxide, expressed in terms of previously reported minimum alveolar concentration values, increased significantly with increasing nitrous oxide concentrations. Conclusions The interaction of isoflurane and nitrous oxide in the dose range 0-75 vol% on median electroencephalographic frequency is compatible with additivity. The potency of nitrous oxide as a substitute for isoflurane is less than on a minimum alveolar concentration basis. Maintaining median electroencephalographic frequency more appropriately reflects the clinical usage of isoflurane and nitrous oxide than does maintaining minimum alveolar concentration.

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The “Extended Brown” Plumage Color Mutant of Blue-Breasted Quail (Coturnix chinensis) is Associated with a Mutation in the Melanocortin 1-Receptor Gene (MC1R)

The Journal of Poultry Science ◽

10.2141/jpsa.0180006 ◽

2018 ◽

Vol 55 (4) ◽

pp. 233-238 ◽

Cited By ~ 4

Author(s):

Miho Kageyama ◽

Atsushi Takenouchi ◽

Keiji Kinoshita ◽

Yoshiaki Nakamura ◽

Masaoki Tsudzuki

Keyword(s):

Receptor Gene ◽

Plumage Color ◽

Melanocortin 1 Receptor ◽

Color Mutant

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Phasic Genioglossus and Palatoglossus Muscle Activity during Recovery from Sevoflurane Anesthesia

Anesthesiology ◽

10.1097/aln.0b013e318295a27b ◽

2013 ◽

Vol 119 (3) ◽

pp. 562-568 ◽

Cited By ~ 2

Author(s):

Ilavajady Srinivasan ◽

Samuel Strantzas ◽

Mark W. Crawford

Keyword(s):

Muscle Activity ◽

Upper Airway ◽

Dependent Manner ◽

Sevoflurane Anesthesia ◽

Phasic Activity ◽

Similar Dose ◽

Inhalational Anesthetic ◽

Recovery From Anesthesia ◽

End Tidal ◽

Dose Dependent

Abstract Background: Inhalational anesthetic effects on upper airway muscle activity in children are largely unknown. The authors tested the hypothesis that phasic inspiratory genioglossus and palatoglossus activity increases during recovery from sevoflurane anesthesia in a dose-dependent manner in children. Methods: Sixteen children, aged 2.0 to 6.9 yr, scheduled for elective urological surgery were studied. Electromyogram recordings were acquired using intramuscular needle electrodes during spontaneous ventilation. After a 15-min period of equilibration, electromyogram activity was recorded over 30 s at each of three end-tidal concentrations, 1.5, 1.0, and 0.5 minimum alveolar concentration (MAC), administered in sequence. Results: Phasic genioglossus activity was noted in four children at 1.5 MAC, five at 1.0 MAC, and six children at 0.5 MAC sevoflurane. Phasic palatoglossus activity was noted in 4 children at 1.5 MAC, 6 at 1.0 MAC, and 10 children at 0.5 MAC sevoflurane. Both the proportion of children exhibiting phasic activity, and the magnitude of phasic activity increased during recovery from anesthesia. For the genioglossus, decreasing the depth of sevoflurane anesthesia from 1.5 to 1.0 MAC increased phasic activity by approximately 35% and a further decrease to 0.5 MAC more than doubled activity (median [range] at 1.5 and 0.5 MAC: 2.7 μV [0 to 4.0 μV] and 8.6 μV [3.2 to 17.6], respectively; P = 0.029). A similar dose-related increase was recorded at the palatoglossus (P = 0.0002). Conclusions: Genioglossus and palatoglossus activity increases during recovery from sevoflurane anesthesia in a dose-dependent manner over the clinical range of sevoflurane concentrations in children.

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Melanocortin-1 receptor gene variants affect pain and -opioid analgesia in mice and humans

Journal of Medical Genetics ◽

10.1136/jmg.2004.027698 ◽

2005 ◽

Vol 42 (7) ◽

pp. 583-587 ◽

Cited By ~ 185

Author(s):

J S Mogil

Keyword(s):

Receptor Gene ◽

Opioid Analgesia ◽

Gene Variants ◽

Melanocortin 1 Receptor

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Characterisation of the melanocortin-1 receptor gene in alpaca and identification of possible markers associated with phenotypic variations in colour

Animal Production Science ◽

10.1071/an09005 ◽

2009 ◽

Vol 49 (8) ◽

pp. 675 ◽

Cited By ~ 21

Author(s):

N. L. Feeley ◽

K. A. Munyard

Keyword(s):

Mus Musculus ◽

Bos Taurus ◽

Receptor Gene ◽

Nucleotide Polymorphisms ◽

Wild Type ◽

Single Nucleotide ◽

Melanocortin 1 Receptor ◽

Mc1r Gene ◽

Pcr Products ◽

Phenotypic Variations

The aim of this study was to determine if any correlation exists between melanocortin-1 receptor (MC1R) polymorphisms and skin and fibre colour in alpacas. Primers capable of amplifying the entire alpaca MC1R gene were designed from a comparative alignment of Bos taurus and Mus musculus MC1R gene sequences. The complete MC1R gene of 41 alpacas exhibiting a range of fibre colours, and which were sourced from farms across Australia, was sequenced from PCR products. Twenty-one single nucleotide polymorphisms were identified within MC1R. Two of these polymorphisms (A82G and C901T) have the potential to reduce eumelanin production by disrupting the activity of MC1R. No agreement was observed between fibre colour alone and MC1R genotype in the 41 animals in this study. However, when the animals were assigned to groups based on the presence or absence of eumelanin in their fibre and skin, only animals that had at least one allele with the A82/C901 combination expressed eumelanin. We propose that A82/C901 is the wild-type dominant ‘E’ MC1R allele, while alpacas with either G82/T901 or G82/Y901 are homozygous for the recessive ‘e’ MC1R allele and are therefore unable to produce eumelanin.

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