Methemoglobinemia, Refractory Cyanosis me ka PaO2 maʻamau, a me Benzocaine a i ʻole Nitrate Toxicity¶

ʻO ka methemoglobinemia i loaʻa, he pilikia hematologic a toxicological e hoʻoweliweli ana i ke ola kahi e hoʻohuli ai nā kemika oxidizing, nā lāʻau lapaʻau, a i ʻole nā ​​​​nitrates kūlohelohe i ka hao i loko o ka hemoglobin ʻulaʻula mai kona kūlana maʻamau e lawe i ka oxygen ferrous state (Fe2+) i loko o ka ferric state (Fe3+). ʻAʻole hiki iā Ferric methemoglobin ** ke hoʻopaʻa a lawe i ka oxygen** a hoʻoikaika i nā pae hemoglobin maʻamau i koe e hoʻopaʻa paʻa i ko lākou oxygen a hiki i nā ʻiʻo i loko o ka lolo a me ka puʻuwai ke ʻeha. Hōʻike ʻia kēia maʻi me kahi triad hauʻoli maikaʻi loa: (1) ʻeleʻele ʻeleʻele a ʻulaʻula-ʻulaʻula paha ka cyanosis waena o nā lehelehe, ke alelo, a me ka ʻili ʻaʻole maikaʻi ke hāʻawi ʻia i ka 100% oxygen, (2) kahi heluhelu pulse oximeter maʻamau e hāʻule a paʻa paʻa ma kahi o 85% SpO2 me ka nānā ʻole ʻana i ke koko ʻulaʻula ma mua o ka ʻulaʻula o ke koko, a me (3) ʻulaʻula ʻulaʻula ma mua o ke koko o ka oxygen. maʻamau a i ʻole kiʻekiʻe dissolved arterial oxygen tension (PaO2). Inā manaʻo ʻoe i ka methemoglobinemia ma hope o ka ʻike ʻana i ka benzocaine a i ʻole lidocaine/prilocaine numbing sprays/gels, inhaled ** nitrite "poppers"**, dapsone, phenazopyridine (AZO), a i ʻole nitrate-contaminated pēpē wai punawai, e kelepona i kāu helu ulia pōpilikia ma o kā mākou. helu pilikia papa kuhikuhi koke i hiki i nā kauka o ka haukapila ke lawelawe i ka antidote intravenous methylene blue, me kā mākou mau alakaʻi no ʻona kōkua mua, ka hoʻokaʻawale ʻana o ka carbon monoxide carboxyhemoglobin, a cyanide a me ka ʻenehana kinoea inhalation.

E hana i kēia i kēia manawa¶

1. Kahea koke aku i kāu helu ulia pōpilikia a me ka Poison Control: Kāhea i ka 911 ma ʻAmelika Hui Pū ʻIa a me Kanada (a me US Poison Control ma 1-800-222-1222), 112 ma waena o ka European Union, 999 ma United Kingdom, 000 ma Australia, a i ʻole e ʻike i kā mākou honua. helu pilikia papa kuhikuhi. E haʻi i ka mea hoʻouna: "Suspected Methemoglobinemia me Refractory Cyanosis: Pono ka Halemai CO-Oximetry a me Intravenous Methylene Blue."
2. Hoʻopau i ka hoʻoheheʻe ʻana a hoʻomaʻemaʻe koke i ka ʻili a i ʻole ka waha:
3. Inā hoʻohana ʻia ka cream/gel anesthetic topical (benzocaine, EMLA lidocaine/prilocaine) i ka ʻili a i ʻole ka ʻāʻī: Holoi i nā koena gel a pau mai ka waha me kahi lole pulu a holoi i ka ʻili me ke kopa a me ka wai mehana koke i ʻole e komo hou ka lāʻau i loko o ka ʻili.
4. Inā ua kahe ʻia nā wai nitrites ("poppers"), nā meaʻulaʻula aniline, a i ʻole nitrobenzene ma ka ʻili a i ʻole ka lole: Wehe koke i nā lole i hoʻohaumia ʻia a holoi i ka ʻili me ka wai kahe no 15 mau minuke i ke kau ʻana i nā mīkina lima.
5. Inā hānai ʻia kahi pēpē i hui ʻia me ka wai punawai ponoʻī: E kāpae koke i ka hoʻohana ʻana i ka wai punawai a e hoʻololi i ka wai ʻōmole a i ʻole ka wai kūloko.
6. E hoʻohana i 100% kiʻekiʻe-holo oxygen hoʻonui ma o ka non-rebreather mask a mālama i ka mea maʻi i ka hoʻomaha piha: ʻOiai ʻo 100% oxygen ʻaʻole ** e hoʻololi koke i nā lehelehe polū/hinahina o ka mea maʻi i ʻulaʻula a i ʻole e kaomi i ka manamana pulse oximeter ma mua o 85%, ʻo ka hanu ʻana i ka 100% oxygen e hoʻonui i ka oxygen i lawe ʻia e ke koena o ka oxygen i lawe ʻia i loko o nā moleke koko koko hou ʻole.
7. E lawe mai i ka omole laau lapaau pololei, ke kini pilau, ka hue popper, a i ole ke kumu wai i ke keena pilikia: Hiki i na kauka ke ike i ka methemoglobinemia i na minuke ke ike lakou i ka omole 20% benzocaine throat/teething spray, phenazopyridine (AZO urinary pain tablets), dapsone, chloroquine/primaritetyl.
8. E ʻōlelo aku i nā kauka o ka haukapila MAMUA o ka hāʻawi ʻana iā Methylene Blue inā he G6PD Deficiency ka mea maʻi a lawe paha i nā Serotonergic Antidepressants (SSRIs/SNRIs):
9. G6PD Deficiency: Pono ka methylene blue i ka enzyme G6PD (no ka hana ʻana i ka NADPH) i mea e hana ai. I nā poʻe maʻi me Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, ʻaʻole pono ka methylene blue a hoʻoulu i ka anemia hemolytic koʻikoʻi e hoʻoweliweli i ke ola ** (puʻi ʻana o nā keʻena koko ʻulaʻula); pono e hoʻohana ʻia i ka intravenous ascorbic acid (vitamin C), riboflavin, a i ʻole hoʻololi hoʻololi.
10. SSRIs / SNRIs / MAOIs: ʻO ka methylene blue he mea ikaika loa Monoamine Oxidase A (MAO-A) inhibitor a hiki ke hoʻomaka. maʻi serotonin i nā maʻi e lawe ana i nā antidepressants.

Laau hoʻoholo: Refractory cyanosis a me ka methemoglobinemia triage¶

flowchart TD
    Start["Hoʻoulu ka maʻi i ka Slate-Gray / Bluish-Purple Central Cyanosis (Lehelehe, Elelo, Moena Nail) + Pōkole o ka hanu, ʻeha poʻo, ʻūlū, a i ʻole Letargy."] --> OxygenTest["E noi i ka 100% High-Flow Oxygen (15 L/min ma o Non-Rebreather Mask) a e nānā i ka Finger Pulse Oximeter"]

    OxygenTest --> PlateauCheck{"'A'ole maika'i ka Cyanosis ma ka 100% Oxygen, a me ka Finger Pulse Oximeter Plateau kokoke i 85% SpO2 (82% a 88%) me nā māmā māmā ma ka Auscultation?"}

    PlateauCheck -->|"ʻAe: Classic Refractory Cyanosis + 85% SpO2 Plateau"| ExposureCheck["METHEMOGLOBINEMIA I MANAʻO: E nānā i nā mea hoʻoheheʻe Oxidant: 1. Nā mea hoʻomaʻemaʻe maʻamau: Benzocaine, Prilocaine, Lidocaine, Cetacaine 2. Nitrites / Nitrates: Poppers (amyl/isobutyl nitrite), wai punawai pēpē, Sodium nitrite 3. ʻO nā lāʻau lapaʻau: ʻO Sodium nitrite 3. ʻO nā lāʻau lapaʻau: ʻO Sodium nitrite 3. ʻO Rasburicase, Metoclopramide 4. ʻOihana: Nā mea pena Aniline, Nitrobenzene, Naphthalene mothballs"]

    ExposureCheck --> HospitalConfirm["Hōʻoia STAT Halemai: 1. E kaha kiʻi i ke koko ʻaʻa a i ʻole ka vena: E nānā i ke kala kokoleka ʻeleʻele ʻaʻole e ʻulaʻula ʻulaʻula ke ʻike ʻia i ka ea 2. ABG + Spectrophotometric Blood CO-Oximetry: - He NORMAL a i ʻole HIGH ka PaO2 i hoʻoheheʻe ʻia (ma luna o 100 a 300 mmHg) - helu ʻia ʻo SaO2 ma luna o 98%, ʻoi aku ka 108% o ka SaO2. Gap vs 85% SpO2 - Hoʻokiʻekiʻe ʻia ka Methemoglobin i ana pololei ʻia (FMetHb %) (Maʻamau ma lalo o 1 a 1.5%)"]

    HospitalConfirm --> SeverityTriage{"E loiloi i ka Methemoglobin% a me nā hōʻailona hōʻailona"}

    SeverityTriage -->|"MetHb 20% a ʻoi aʻe paha i ka maʻi hōʻailona A i ʻole MetHb 30% a i ʻole ke kiʻekiʻe i ka maʻi Asymptomatic (A i ʻole 10% a i 15% a ʻoi aʻe paha inā he maʻi puʻuwai/māmā a i ʻole anemia)"| G6PDCheck{"Ua ʻike paha ka mea maʻi i ka hemahema o G6PD (a i ʻole lawe iā Rasburicase)?"}

    G6PDCheck -->|"NO G6PD hemahema"| GiveMB["ADMINISTER FIRST-LINE ANTIDOTE: INTRAVENOUS METHYLENE BLUE - Dose: 1 mg/kg i 2 mg/kg (0.1 a i 0.2 mL/kg o 1% solution) IV lohi ma luna o 5 mau minuke - Hoʻopono pū i ka IV Dextrose (D5W) inā hypoglycemic no laila e hoʻoheheʻe ai ka NADPH me ka phosphate phosphate ma lalo o ke ala. 5% i loko o 30 a 60 mau minuke - E hana hou i ka 1 mg/kg ma ka 30 a i ka 60 min inā noho kiʻekiʻe ka MetHb (Max total dose 7 mg/kg)"]

    G6PDCheck -->|"ʻAe: ʻIke ʻia/Manaʻo ʻia ʻo G6PD Deficiency (Methylene Blue CONTRAINDICATED)"| AltRescue["NON-G6PD RESCUE PROTOCOL: - Mai hāʻawi i ka Methylene Blue (ke kumu i ka hemolysis make a me ka piʻi ʻana o ka MetHb paradoxical) - Hoʻoponopono i ka High-Dose IV Ascorbic Acid (Vitamin C: 1 g i 10 g IV i māhele ʻia) - E noʻonoʻo i ka High-Dose Riboflavin (Vitamin B2), a i ʻole Redbaric Cell Transgenfusion."]

    SeverityTriage -->|"Mild MetHb (ma lalo o 20%) A me Asymptomatic me ka hana maʻamau o ka naʻau a me ka māmā"| ConservativeWashout["Wehe/Decontaminate Oxidant Trigger + 100% Oxygen: Natural Cytochrome b5 Reductase enzyme hoʻomaʻemaʻe i ka MetHb ma kahi o 15% i kēlā me kēia hola. E nānā pono no 6 a 24 mau hola (e nānā iā Dapsone rebound)"]

Pathophysiology: Pehea ka ferric iron (Fe3+) e hoʻopaʻa i ka oxygen a hoʻololi i ke koko kokoleka-ʻeleʻele¶

1. ʻO Ferrous (Fe2+) vs. Ferric (Fe3+) Hemoglobin a me ka ʻAha Hoʻololi hema.¶

I loko o kēlā me kēia pūnaʻi koko ʻulaʻula kanaka olakino, aia ka hemoglobin i ʻehā mau kaulahao protein, e paʻa ana kēlā me kēia i kahi atom hao ma ke kikowaena o kahi apo porphyrin heme. No ka hoʻopaʻa ʻana o ka hemoglobin i ke kinoea oxygen (O2) i loko o ka māmā a hoʻokuʻu i ka lolo a me ka puʻuwai, pono e mālama ʻia kēlā atom hao ** i loko o ke kūlana ferrous emi (Fe2+)**.

I ka wā e wehe ai ka lāʻau hoʻoheheʻe a i ʻole kemika i kahi electron mai kēlā ʻātoma hao, ua ʻoki ʻia ka hao i loko o ka ferric state (Fe3+), e hoʻololi ana i ka hemoglobin maʻamau i methemoglobin (MetHb). Hoʻokumu kēia electron nalowale i ʻelua mau pōʻino physiological i ka manawa like: 1. Nalo pololei o ka hiki ke lawe i ka oxygen: Ferric iron (Fe3+) i loko o ka methemoglobin ʻaʻole hiki ke hoʻopaʻa i ka oxygen i nā mea a pau; akā, ua hoʻopaʻa ʻia kona kahua hoʻohui ʻeono i kahi mole wai (H2O) a i ʻole hui hydroxyl (OH-). 2. Allosteric Leftward Shift o nā Pae Heme i koe: E like me ka carbon monoxide, ke hoʻoheheʻe ʻia hoʻokahi a ʻelua paha o nā wahi heme ʻehā i loko o ka hemoglobin tetramer i Fe3+, hoʻololi ke ʻano o ka mole hemoglobin holoʻokoʻa (allosteric cooperativity). ʻO nā paena heme Fe2+ maʻamau i koe ma ia mole hoʻokahi ** e hoʻonui i ko lākou pili no ka oxygen **, e hoʻololi i ka oxyhemoglobin dissociation curve i ka hema. ʻO ka hopena, hōʻole nā ​​wahi heme oxygen i koe e hoʻokuʻu i kā lākou oxygen i ka wā e hele ai i nā capillaries hypoxic, e hōʻeha ana i ka hypoxia cellular a me ka lactic acidosis.

2. No ke aha i loaʻa ai i nā kānaka olakino ma lalo o 1% methemoglobin wale nō (a no ke aha e pilikia ai nā pēpē)¶

ʻOiai i loko o ka poʻe olakino e hanu ana i ka ea maʻamau, ua hoʻoneʻe ʻia ka hemoglobin liʻiliʻi i ka methemoglobin i kēlā me kēia lā (ma kahi o 0.5% a 3% i kēlā me kēia lā). ʻO ka mea pōmaikaʻi, loaʻa i nā pūpū koko ʻulaʻula kahi enzyme mālama hale i kapa ʻia ʻo Cytochrome b5 Reductase (NADH-dependent methemoglobin reductase), ʻo ia ka helu o 95% a 99% o ka hoʻomaʻemaʻe methemoglobin i kēlā me kēia lā a hāʻawi mau i nā electrons mai NADH e hoʻihoʻi i ka Fe3+ i Fe2+ hana, e mālama ana i nā pae methemoglobin1 maʻamau.

No ke aha i maʻalahi ai ** nā kamaliʻi ma lalo o 4 a 6 mau mahina** i ka methemoglobinemia make ("Blue Baby Syndrome") mai ka wai punawai, ka acidosis diarrheal, a i ʻole nā ​​gel niho? 1. Immature Cytochrome b5 Reductase Enzyme: Loaʻa i nā pēpē hou a me nā pēpē ma lalo o 4 mahina o ka makahiki ** he 50% wale nō o ka hana makua o cytochrome b5 reductase**, ʻo ia hoʻi, hoʻomaʻemaʻe lākou i ka hapa methemoglobin me ka wikiwiki e like me nā pākeke. 2. Hemoglobin Fetal (HbF) Hoʻokiʻekiʻe ʻelua e like me ka wikiwiki: Aia nō i ke koko pēpē nā pākēneka kiʻekiʻe o hemoglobin fetal (HbF), ka mea i hoʻokahe ʻia ma ke kemika mai Fe2+ a i Fe3+ ʻoi aku ka maʻalahi ma mua o ka Hemoglobin A makua. 3. ** ʻO ka pH kiʻekiʻe o ka ʻōpū e ʻae ai i ka Nitrate-Converting Bacteria e ulu aʻe**: ʻO ka ʻōpū o kahi pēpē ʻoi aku ka liʻiliʻi o ka waikawa (pH ma luna o 4.0) ma mua o ka ʻōpū o ke kanaka makua. ʻO kēia pH kiʻekiʻe o ka ʻōpū e hiki ai i ka nitrate-reducing intestinal bacteria (E. coli, Salmonella) ke ulu kiʻekiʻe i loko o ka ʻōpū o ka pēpē a me ka ʻōpū liʻiliʻi o luna, kahi e hoʻololi wikiwiki ai lākou i ka ** meaʻai nitrates (NO3-)** mai ka wai punawai kuaʻāina a i ʻole nā ​​​​huaʻai aʻa homemade i potent oxidizing nitrites (NO2-).

ʻEkolu mau hōʻailona hōʻailona: ke koko kokoleka, ka 85% SpO2 Plateau, a me ka Saturation Gap¶

1. No ke aha la e Laka ai na Oximeters Finger Pulse ma 85% SpO2 (Beer-Lambert Optical Ratio R = 1.0)¶

E like me ka wehewehe ʻana i kā mākou alakaʻi hoʻāʻo kalapona monoxide, he oximeter pulupulu manamana lima maʻamau ʻelua-lōʻihi e ʻālohilohi 660 nm (kukui ʻulaʻula) a me 940 nm (kukui infrared) ma o ka manamana lima a helu i ka ratio absorption (R = Absorption ma 660 nm i puunaueia e Absorption ma 940 nm): - Hoʻopili ka deoxyhemoglobin maʻamau i ka māmā 660 nm, ʻoiai ʻo ka oxyhemoglobin maʻamau e hoʻopili i nā kukui 940 nm. - Methemoglobin (MetHb), naʻe, hoʻopili like nā kukui ʻulaʻula 660 nm a me nā kukui infrared 940 nm. - I ka piʻi ʻana o ka methemoglobin i ke koko ma luna o 20% a 35%, ʻoi aku ia ma luna o ka lawe māmā ʻana ma nā lōʻihi nalu ʻelua, e koi ana i ka ratio optical R pololei i 1.0. Ma ka pihi calibration kūloko i hoʻolālā ʻia i loko o kēlā me kēia oximeter pulse maʻamau, ʻo ka ratio optical o R = 1.0 pili i kahi heluhelu SpO2 o 85% (82% a 88%). - Hoʻokumu kēia i kahi paradox maʻamau: inā loaʻa i ka mea maʻi he 30% methemoglobin (hōʻailona haʻahaʻa) a i ʻole he 70% methemoglobin make (e make ana i loko o ka coma), e paʻa paʻa ka oximeter pulse manamana ma kahi o 85% SpO2.

2. ʻO ka "Oxygen Saturation Gap" (Ma luna o 5% a 10%) a me ka PaO2 maʻamau¶

Ke huki nei nā kauka ulia pōpilikia i ke kinoea koko arterial (ABG) mai kēia mea maʻi ʻulaʻula ʻulaʻula nona ka manamana lima he 85%, ʻike lākou i kahi hopena kupaianaha: - ** ʻO ke ʻano Oxygen Partial Pressure (PaO2) he NORMAL a i ʻole SKY-HIGH (100 a 400+ mmHg ma ka oxygen) **, no ka mea, ʻo PaO2 wale nō ke ana ʻana i ke kinoea oxygen i hoʻoheheʻe ʻia i loko o ka plasma wai māmā, ʻaʻole i hoʻopilikia ʻia e ka hemoglobin. - No ka mea, ua loaʻa mai ka mīkini kinoea koko helu ʻia oxygen saturation (SaO2) mai kēlā PaO2 maʻamau, hōʻike ka mīkini i ka helu SaO2 o 98% a 100%. - ʻO ka ʻokoʻa ma waena o ka 98% a hiki i ka 100% helu ABG saturation a me ka 85% finger pulse oximeter reading ua kapa ʻia he Oxygen Saturation Gap (ma luna o 5% a hiki i 10%), he hōʻailona diagnostical maʻamau e kuhikuhi pololei ana iā methemoglobinemia (a i ʻole sulfhemoglobinemia / cyanide). Pono ka hoʻopaʻa ʻana e holo i ke koko ma o multi-wavelength Spectrophotometric Blood CO-Oximeter, nāna e ana pololei i ka FMetHb%.

3. Ka "Kokoleka-Brown Blood" kānana-Pepa Moe Ho'āʻo¶

ʻO ke koko venous maʻamau he poni-ʻulaʻula ʻeleʻele a lilo i ** ʻulaʻula ʻulaʻula ʻulaʻula i loko o kekona** ke ʻike ʻia i ka ea lumi a i ʻole ka pohu me ka oxygen. ʻO ka ʻokoʻa, ʻo ke koko i loko o ka 15% a i ka 20% methemoglobin a i ʻole ke kiʻekiʻe aʻe he ʻano ** ʻeleʻele-ʻeleʻele-ʻeleʻele, ʻōpala, a i ʻole espresso kala** i loko o ka syringe. Inā kau ke kahu hānai i hoʻokahi kulu o ke koko o ka mea maʻi ma luna o ka pepa kānana keʻokeʻo ma kahi kokoke i kahi kulu o ke koko maʻamau a nalu i ka lewa no 30 kekona (a i ʻole e puhi i ka oxygen ma luna), e huli ke koko maʻamau i ka cherry-ulaʻula a ʻo ke koko methemoglobinemic ** noho ʻeleʻele-ʻeleʻele**.

ʻO nā lāʻau lapaʻau maʻamau, nā kemika, a me nā kumu wai e hoʻoulu ai i ka methemoglobinemia¶

ʻO ke alapiʻi koʻikoʻi o ke kino: Nā hōʻailona ma ka pākēneka Methemoglobin (MetHb%)¶

(E hoʻomaopopo: Ke manaʻo nei kēia mau pākēneka i ka hemoglobin baseline olakino o 14 a 15 g/dL. Inā loaʻa ka maʻi i ka anemia [e.g., hemoglobin 8 g/dL], ʻeha puʻuwai, a i ʻole COPD, ʻike ʻia nā hōʻailona hypoxic koʻikoʻi ma ** hapalua* o kēia mau pākēneka no ka mea he emi loa ka hemoglobin hana i koe.)*

Pehea e hana ai ka Antidote Methylene Blue (A me ka G6PD Deficiency Trap)¶

1. Ke Alanui NADPH Li'ili'i e Ho'okē ai ka Methylene Blue¶

Ma lalo o nā kūlana maʻamau, hoʻohana ke koko ʻulaʻula i ka NADH-dependent Cytochrome b5 Reductase ala e hoʻomaʻemaʻe i ka 99% o ka methemoglobin i kēlā me kēia lā. Eia nō naʻe, loaʻa nō i nā keʻena koko ʻulaʻula ka lua, ʻo ka mea maʻamau moe ʻana i ka enzyme backup i kapa ʻia ʻo NADPH-Methemoglobin Reductase, e hoʻohana ana i ka NADPH i hana ʻia e Glucose-6-Phosphate Dehydrogenase (G6PD) ma ke ala pentose phosphate (hexose monophosphate shunt).

Ma kāna iho, hana lohi loa ʻo NADPH-Methemoglobin Reductase no ka mea ʻaʻohe mea lawe uila-shuttle kūlohelohe. ** Intravenous Methylene Blue (1 a 2 mg/kg o kahi 1% solution [10 mg/mL] i hoʻokomo mālie ʻia ma luna o 5 mau minuke)** hana ʻo ia ma ke ʻano he ka uila uila artificial: 1. I loko o ke koko ʻulaʻula, hoʻohana ʻo NADPH-Methemoglobin Reductase i ka NADPH (hana ʻia e G6PD) e hoʻemi i ka uliuli Methylene Blue i loko o ka waihoʻoluʻu Leukomethylene Blue. 2. Hāʻawi koke ʻo Leukomethylene Blue i kāna electron i ka hao ferric (Fe3+) o methemoglobin, e hoʻihoʻi iā ia i loko o ka hao hao hao (Fe2+) lawe oxygen maʻamau i loko o 30 a 60 mau minuke. 3. (Practical Clinical Tip: No ka mea e pono ai i ke koko ʻulaʻula ka glucose no ka holo ʻana i ke ala pentose phosphate a hana i ka NADPH, hōʻoia ka poʻe toxicologists o ka haukapila he kō koko maʻamau ka mea maʻi, a i ʻole hoʻokomo i ka methylene blue me 5% Dextrose [D5W], no laila ʻaʻole pau ka wahie o ke koko ʻulaʻula no ka antidote.) 4. (Pulse Oximeter Note Ma hope o ka hāʻawi ʻana i ka Methylene Blue: No ka mea, ʻo ka methylene blue he kala ʻulaʻula hohonu e kahe ana i loko o ke kahe koko e hoʻopaʻa ikaika i ke kukui ʻulaʻula 660 nm, ** ʻo ka hoʻokomo ʻana i ka methylene blue i loko o ke koko e hāʻule koke ka heluhelu oximeter pulse i ka 65% a 75% no 2 a hiki i ka 10 mau minuke ʻōmaʻomaʻo ʻole ka ʻili. kala* no 24 a 48 hola.)*

2. No ke aha i hoʻopaʻa ʻole ʻia ai ka Methylene Blue i ka hemahema o G6PD (A ʻoi aku ma luna o 7 mg/kg)¶

• Ka G6PD Deficiency Trap: No ka hilinaʻi piha ʻana o ka methylene blue i ka NADPH i hana ʻia e ka G6PD enzyme, ʻaʻole hiki i ka mea maʻi me Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency (he maʻi X-linked genetic maʻamau i nā poʻe o Mediterranean, ʻApelika, Middle Eastern, a me ʻAsia Hikina Hema) ** ʻaʻole hiki ke hoʻololi i ka leumethylkomethylene blue. ʻO ka ʻoi aku ka ʻoi aku ka maikaʻi, ʻo ka methylene blue i hoʻemi ʻole ʻia he oxidant nāna e ʻaihue i nā wahi liʻiliʻi o ka glutathione i waiho ʻia e ka cell deficient G6PD, e hoʻoulu ai i ka masive acute Heinz-body hemolytic anemia (ka luku ʻana i nā ʻāpana koko ʻulaʻula o ka mea maʻi) a me ka hoʻomāhuahua ʻana i ka methemoglobinemia.
• He aha nā kauka e hoʻohana ai i ka G6PD Deficiency: High-dose intravenous Ascorbic Acid (Vitamin C: 1 a 2 grams IV i kēlā me kēia 6 hola, a hiki i ka 10 grams i nā hihia koʻikoʻi) (e hōʻemi pololei i ka methemoglobin me ka ʻole o ka G6PD/NADPH, ʻoiai ʻoi aku ka lohi ma mua o 12 a hiki i ka 24 mau hola), Vitamino intravenous (Vitamino B) Oxygen Therapy (HBOT), a i ʻole ** ka hoʻololi ʻana i ke koko ʻulaʻula maʻemaʻe**.
• ** ʻO ka 7 mg/kg Ceiling**: ʻOiai i nā poʻe maʻi me ka G6PD maʻamau, ʻo ka methylene blue he mea hoʻoheheʻe hoʻoheheʻe ʻia i nā kumu nui. ʻAʻole pono e ʻoi aku ka nui o ka methylene blue dosing ** ma mua o 7 milligrams no ka kilo**, no ka mea, ʻo ka nui o ka nui ma luna o 7 mg/kg ke kumu e ʻeha ai ka umauma, dyspnea, hemolysis, a me paradoxically induce methemoglobinemia.
• Sulfhemoglobinemia Mimic: Hiki i kekahi mau lāʻau i loaʻa i ka sulfur (e like me sumatriptan, phenazopyridine, dapsone, a i ʻole metoclopramide) i kekahi manawa ke hoʻoheheʻe i ka hemoglobin a hoʻokomo i kahi ʻātoma sulfur i loko o ke apo porphyrin, e hana ana i sulfhemoglobin (SulfHb). Ua like ke ʻano o ka sulfhemoglobin me ka methemoglobin (cyanosis, koko kokoleka, 85% SpO2) koe wale nō ʻaʻole hiki ke hoʻohuli ʻia ka sulfhemoglobin a ʻaʻole pane i ka methylene blue (koi i ka mālama kākoʻo a hoʻololi i ka hoʻololi ʻana a hiki i ka huli ʻana o ke koko ʻulaʻula).

Nā helu ulia pōpilikia āpana a me nā protocols oihana¶

• ** ʻAmelika Hui Pū ʻIa a me Kanada **: E kelepona koke iā 911 a e nīnau iā Poison Control ma 1-800-222-1222 (US) a i ʻole 1-844-POISON-X (Kanada). ʻO kēlā me kēia keʻena ulia pōpilikia o ka haukapila e mālama i 1% Methylene Blue injection (ProvayBlue, 50 mg/10 mL [5 mg/mL] a i ʻole 10 mg/mL vials) ma lalo o American College of Medical Toxicology (ACMT) a me AAPCC antidote stocking guidelines. ʻO ka palekana wai punawai pilikino e hahai i ka U.S. ʻO ka pae hoʻohaumia kiʻekiʻe loa o ka EPA (MCL) o 10 mg/L Nitrate-Nitrogen.
• United Kingdom: E kelepona iā 999 no kahi kaʻa kaʻa ulia pōpilikia (a i ʻole NHS 111 / NPIS TOXBASE no ke alakaʻi ʻana i ke kino). Ma UK, ua kapa inoa ʻia ka antidote injectable Methylthioninium chloride (Methylene Blue) a ua hoʻopaʻa ʻia ʻo ia ma ke ʻano he antidote o ka ʻoihana pilikia pilikia ma lalo o ** Royal College of Emergency Medicine (RCEM) a me NPIS ** alakaʻi.
• Uni ʻEulopa: Kāhea i ka 112 ma nā mokuʻāina lālā a pau o EU. Hāʻawi nā hui halemai i ka Methylthioninium chloride (Proveblue) ma hope o European Medicines Agency (EMA) a me nā kuʻina o ke kikowaena o nā mea make; hoʻoponopono ʻia nā nitrates wai inu ma lalo o ka EU Nitrates Directive (50 mg/L like NO3-).
• Australia a me New Zealand: E kelepona iā 000 ma Australia a i ʻole 111 ma New Zealand, a e nīnau i ka Poisons Information Center ma 13 11 26 (Australia) a i ʻole 0800 764 766 (New Zealand).
• India a me Asia-Pacific: Kāhea i ka 112 ma India, 995 ma Singapore, 119 ma Iapana a me South Korea, a i ʻole 999 ma Hong Kong a me Malaysia. Ma nā wahi ʻoihana mahiʻai a me nā mea hana wai, mālama ʻia ka aniline, nitrobenzene, a me nā mea ʻawaʻawa nitrate mahiʻai me ka decontamination ʻili wikiwiki, intravenous methylene blue, a me G6PD screening.

Nīnau pinepine¶

No ke aha e hāʻule ai ka oximeter pulse manamana ma kahi o 85% a paʻa i laila i ka wā methemoglobinemia?¶

E helu ana ka oximeter pulupulu manamana lima ma ke ana i ka ratio o ka malamalama i komo ma na nalu nalu elua: 660 nanometers (kukui ulaula) a me 940 nanometers (kukui infrared). ʻOiai ʻokoʻa loa ka ʻokoʻa o ka oxygenated a me ka hemoglobin deoxygenated i kēia mau nalu nalu ʻelua, ʻokoʻa loa ka ferric methemoglobin i ka māmā 660 nm a me 940 nm, e hoʻohuli ana i ka ratio absorption optical i 1.0. I loko o kēlā me kēia polokalamu pulse oximeter maʻamau, ʻo ka lākiō absorption o 1.0 unuhi i kahi heluhelu SpO2 ma kahi o 85%. No laila, ke oi aku ka methemoglobin ma mua o 25% a i ka 35%, laka ka oximeter kokoke i 85% inā he ma'i ha'aha'a a make ko'iko'i paha ka mea ma'i ma 70% methemoglobin.

No ke aha e pōʻino ai ka hoʻolapalapa ʻana i ka wai punawai pilikino e hana ai i ka meaʻai pēpē inā he nitrates ka wai?¶

ʻAʻole like me ka bacteria a i ʻole nā ​​maʻi maʻi, ʻo ka nitrates he mau paʻakai kemika i hoʻoheheʻe ʻole ʻia ke hoʻolapalapa ʻia ka wai. Ke hoʻolapalapa ʻoe i ka wai punawai i hoʻopōʻino ʻia i ka nitrate ma luna o ka umu, e mahuka ana ka mahu maʻemaʻe aʻo ka 100 pākēneka o nā nitrates e waiho ana ma hope o ka ipuhao, e ʻoi aku ka kiʻekiʻe o ka neʻe ʻana o ka nitrate a ʻoi aku ka pōʻino no ka pēpē. Pono e ho'āʻo ʻia nā pūnāwai kūʻokoʻa kūʻokoʻa i kēlā me kēia makahiki no nā nitrates (pono ma lalo o 10 mg/L Nitrate-Nitrogen) ma mua o ka hoʻohana ʻia ʻana no ka hoʻohui ʻana i nā mea hānai pēpē no nā pēpē ma lalo o 6 mahina.

No ke aha i like ai ke koko o ka mea maʻi me he syrup kokoleka ʻeleʻele i ka wā i huki ai ke kahu i loko o ka lumi pilikia?¶

ʻO ka hemoglobin maʻamau i loaʻa ka hao hao (Fe2+) e huli ʻulaʻula ʻulaʻula ʻulaʻula ke hoʻopaʻa ʻia ka oxygen. Ke hoʻololi ʻia nā kinikona oxidizing e like me benzocaine, nitrites, a i ʻole dapsone i kēlā hao i loko o ke kūlana ferric (Fe3+ / methemoglobin), ʻaʻole hiki i ke apo heme i hoʻololi ʻia ke hoʻopaʻa i ka oxygen a hōʻike i ka mālamalama i ka spectrum ʻeleʻele. Ke loaʻa ka methemoglobin ma mua o 15% a i ka 20% o ka hemoglobin holoʻokoʻa, lawe ʻia ke koko kokoleka a me ka venous i kahi waihoʻoluʻu ʻulaʻula-ʻulaʻula ʻaʻole hiki ke ʻulaʻula inā ʻike ʻia i ka ea lumi a i ʻole ka oxygen maʻemaʻe.

No ke aha e hiki ʻole ai i nā kauka ke hāʻawi i ka antidote Methylene Blue i kekahi me ka hemahema G6PD?¶

ʻAʻole hoʻemi pololei ka Methylene blue i ka methemoglobin iā ia iho; i loko o ke koko ʻulaʻula, pono e hoʻololi mua ʻia i loko o ka leukomethylene blue me ka hoʻohana ʻana i ka NADPH i hana ʻia e ka enzyme Glucose-6-Phosphate Dehydrogenase (G6PD). Inā loaʻa ka hemahema G6PD i ka mea maʻi, ʻaʻole hiki i kā lākou mau keʻena koko ʻulaʻula ke hana i ka NADPH lawa e hoʻāla ai i ka methylene blue. Akā, hana ka polū methylene i hoʻemi ʻole ʻia ma ke ʻano he oxidant nāna e hoʻopau i ke koena o ka glutathione pale o ke kelepona, e hoʻopiʻi nui ai i nā ʻulaʻula ʻulaʻula (acute hemolytic anemia) me ka hoʻoponopono ʻole i ka methemoglobinemia. Hana nā kauka i nā poʻe maʻi nele i ka G6PD me ka hoʻohana ʻana i ka vitamin C (ascorbic acid) a i ʻole ka hoʻololi ʻana i ke koko ʻulaʻula.

No ke aha i huli ai ka mimi o ka mea maʻi i polū-ʻōmaʻomaʻo a hāʻule ka pulse oximeter i 70% ma hope o ka loaʻa ʻana o ka lāʻau antidote Methylene Blue?¶

Manaʻo loa ʻia nā hopena ʻelua a ʻaʻohe pōʻino. ʻO ka methylene blue ka mea hoʻonanea ʻulaʻula hohonu: ʻoiai kaʻapuni ʻo ia ma ke kahe koko i ka 2 mua a 10 mau minuke ma hope o ke kaomi ʻana i ka IV, ʻo ka ʻulaʻula ʻulaʻula ponoʻī e komo i ka 660 nm kukui ʻulaʻula ma ka manamana lima, e hoʻoulu ai i kahi manawa hoʻoheheʻe ʻia ma ka manamana pulse oximeter ʻoiai ʻo ka ʻili o ka mea maʻi e ʻulaʻula a ʻo ko lākou koko methemoglobin e hoʻoheheʻe maʻamau. A laila kānana nā puʻupaʻa i ka wai i loko o ka mimi, e hoʻololi i ka mimi i uliuli a ʻōmaʻomaʻo paha no 24 a 48 mau hola.

• Hāʻawi kēia alakaʻi i ka ʻike hoʻonaʻauao pilikia a ʻaʻole ia e pani i ka mālama lapaʻau ʻoihana a i ʻole ke kūkākūkā Poison Control. Ma muli o ke kumu o ka methemoglobinemia koʻikoʻi ke kumu o ka hypoxia cellular wikiwiki, ka hopu ʻana, a me ka hopu ʻana i ka naʻau, manaʻo nui mākou e lawe i kahi kōkua mua a me ka papa CPR i hōʻoia ʻia mai ke Keʻa ʻulaʻula, St John Ambulance, a i ʻole kekahi mea hoʻomaʻamaʻa kūloko kūloko.*

Nā alakaʻi pili¶

• ʻO ka hoʻāʻo ʻana o ka carbon monoxide poisoning, pulse oximeter nā heluhelu wahaheʻe, a me ka oxygen hyperbaric
• ʻO ka cyanide, hydrogen sulfide, a me ke kinoea inhalation kōkua mua
• Serotonin syndrome, neuroleptic malignant syndrome, a me nā pilina lāʻau
• ʻO ke kōkua mua a me ka hoʻāʻo ʻana i ka lāʻau make
• ʻO nā pilikia ulia pōpilikia: SVC maʻi, hoʻopiʻi ʻana i ka iwi kuamoʻo, a me ka lysis tumor (rasburicase)

Nā kumu a me ke alakaʻi kūhelu¶

• ** American College of Medical Toxicology (ACMT) and American Association of Poison Control Centers (AAPCC, United States):** Expert Consensus Guidelines for the Stocking and Administration of Antidotes in Emergency Department: Intravenous Methylene Blue for Acquired Methemoglobinemia.
• U.S. Food and Drug Administration (FDA, United States) and Medicines and Healthcare products Regulatory Agency (MHRA, United Kingdom): Drug Safety Communications: Risk of Serious and Potentially Fatal Blood Disorder (Methemoglobinemia) with Over-the-Counter Benzocaine Teething Products and Topical Anesthetic Sprays.
• World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA): Alakaʻi no ka maikaʻi o ka wai inu: Nitrate a me Nitrite i ka wai inu a me ka pale ʻana i ka pēpē Methemoglobinemia.
• ** ʻOihana Hoʻonaʻauao Lapaʻau Lahui (NPIS / TOXBASE) a me ka Royal College of Emergency Medicine (RCEM, United Kingdom):** Antidote Guideline for Methylthioninium Chloride (Methylene Blue) i ka Methaemoglobinaemia a me ka Management in G6PD Deficiency.
• European Medicines Agency (EMA): Summary of Product Characteristics and Clinical Dosing Protocol for Proveblue (Methylthioninium Chloride) in Pediatric and Adult Acquired Methemoglobinemia.