EBO2 (EBOO) glossary

Plain-language definitions of the terms clinics and papers use when talking about EBO2 (also called EBOO) and ozone therapy.

10-pass ozone (also: 10 pass, hyperbaric ozone, OHT, ozone high-dose therapy)

A higher-dose form of major autohemotherapy. As described in a 2022 paper co-written by the method's pioneer, 200 mL of blood is drawn into a vacuum bottle containing heparin, 200 mL of oxygen/ozone gas at 70 µg/mL is pumped in under pressure, and the blood is returned using positive pressure. That is one pass; nine more follow, and the ten passes take about an hour.

21 CFR 801.415 (also: 21 CFR § 801.415, FDA ozone regulation)

The FDA device regulation stating that ozone is a toxic gas with no known useful medical application in specific, adjunctive, or preventive therapy. It sets a maximum acceptable ozone level of 0.05 parts per million in air for devices that generate ozone, and treats such a device as adulterated or misbranded if it is used for any medical condition for which there is no proof of safety and effectiveness.

510(k) clearance (also: 510(k), premarket notification, FDA cleared, FDA clearance)

The FDA's finding, after a manufacturer files a premarket notification known as a 510(k), that a new device is substantially equivalent to a device already on the US market, which allows it to be sold. FDA regulation 21 CFR 807.97 states that this finding does not in any way denote official approval of the device, and that any claim giving the impression of official approval because of it is misleading and counts as misbranding.

Adverse event (also: AE, serious adverse event)

Any harmful or unwanted medical occurrence in a person after a treatment, whether or not the treatment caused it. FDA's drug-trial rules define it this way, call an event serious if it causes death, is life-threatening, requires or prolongs a hospital stay, causes lasting incapacity, or causes a birth defect, and reserve the term adverse reaction for an event the treatment caused.

Anticoagulation during EBO2 (also: blood thinning during treatment)

Adding an anticoagulant, a drug that reduces the blood's ability to clot, to blood that is being treated outside the body. A 2005 review by the Siena group that developed EBOO describes an apparatus that can treat up to 4,800 mL of heparinized blood with an oxygen/ozone mixture during one hour of extracorporeal circulation.

Apheresis (also: blood component separation, pheresis)

A process in which a machine takes blood from a person through a catheter, separates out and removes one part, such as plasma, platelets, white or red blood cells, or blood stem cells, and returns the rest to the body. It may be done to collect blood stem cells before a transplant or to remove abnormal blood cells or proteins, and it is used to treat some blood disorders, blood cancers, autoimmune disorders, and other conditions.

Autohemotherapy (also: ozone autohemotherapy, autohaemotherapy, ozonated autohemotherapy, O3-AHT)

Treating a patient's own blood with an oxygen/ozone gas mixture outside the body and giving it back. A 2011 paper by ozone-therapy researchers Bocci, Zanardi, and Travagli divides ozonated autohemotherapy by blood volume into major autohemotherapy, which treats 100 to 225 mL of blood and reinfuses it into a vein, and minor autohemotherapy, which treats about 5 mL and injects it into a buttock muscle, and lists EBOO alongside them.

Biomarker (also: biological marker, marker)

A characteristic that is measured as an indicator of normal biological processes, disease processes, or responses to an exposure or treatment, such as a molecular, imaging, or physiologic measurement. FDA notes that a biomarker is not an assessment of how a person feels, functions, or survives, so a change in one is not, on its own, evidence that patients are better off.

Blinding (masking) (also: blinded study, double-blind, single-blind, masking, masked study)

Keeping trial participants, and sometimes the research team, from knowing who is receiving which treatment, so that this knowledge does not bias what is reported. In a single-blind study the participants are not told but the research team knows; in a double-blind study neither knows, though the treatment can always be revealed if medically necessary.

Case report (also: case study, clinical case report)

A published, detailed account of the clinical course of an individual patient. Case reports are often the first notice of a new disease, a rare condition, or an unexpected adverse effect, but with so few patients they cannot show that a treatment caused an outcome or how often something happens, which places them low on the evidence hierarchy.

Case series (also: uncontrolled case series)

A study that describes a series of patients, usually all given the same treatment, with observations before and after it but no control group. Because case series are uncontrolled, many systematic reviews of non-randomized studies leave them out. The line between case series and cohort studies is blurry: one study found that about 72% of cohort studies had been mislabeled as case series.

Chelation therapy (also: chelation, EDTA chelation)

Giving, through a vein, a substance that binds metals or minerals so they can be removed from the body in urine. As a complementary treatment for coronary heart disease, EDTA chelation is not FDA-approved, and a second large NIH-funded trial, TACT2, reported in 2024 that it lowered blood lead but did not reduce cardiovascular events. Its most important serious side effects are low blood calcium and kidney damage.

Chronic inflammatory response syndrome (CIRS) (also: mold illness, biotoxin illness)

A diagnosis that its supporters describe as a dysregulation of the innate immune system after breathing the air of water-damaged buildings, with symptoms in several organ systems at once. The authors of a 2024 review that supports the diagnosis call it under-recognized and often misdiagnosed as chronic fatigue syndrome; they found 13 published articles on treating it, 11 of them describing one approach, the Shoemaker Protocol.

Class II medical device (also: Class II device, Class 2 device, moderate-risk device, FDA device classes)

The middle of the FDA's three risk-based device classes. Class I devices are low risk and subject to general controls only. Class II devices, such as dialysis equipment and many catheters, are moderate risk, can carry special controls such as testing or labeling rules, and are generally marketed through 510(k) clearance. Class III devices are the highest risk and generally need premarket approval. The class applies to the device; FDA says it does not approve health care providers.

Cohort study (also: cohort, prospective cohort study, retrospective cohort study)

An observational study in which a defined group of people is followed over time to examine how the treatments or exposures they received relate to later outcomes. Unlike a case series, a cohort study compares groups, such as people who did and did not receive a treatment; unlike a randomized trial, it is a non-randomized design.

Confidence interval (CI) (also: CI, 95% confidence interval, 95% CI)

A range of values around a study's result that describes the uncertainty in the estimate, often read as the range in which the true effect probably lies. Strictly, if a study were repeated many times, 95% of the 95% confidence intervals calculated would contain the true effect. A narrow interval means the effect is known precisely; a very wide one, often from a small study, means little is known.

Conflict of interest (also: conflicts of interest, competing interests, COI, financial conflict of interest)

A situation that creates a risk that a person's professional judgment or actions on a primary interest, such as giving an unbiased estimate of a treatment's effect, will be unduly swayed by a secondary interest, which can be financial or non-financial. Cochrane notes that conflicts of interest are probably one of several important reasons trials with negative findings go unpublished.

Diabetic foot ulcer (also: diabetic foot, foot ulcer, DFU)

An open sore on the foot of a person with diabetes. High blood sugar can damage the nerves and blood vessels of the feet, so a wound may go unnoticed and heal poorly because of reduced blood flow; infection plus poor circulation can lead to gangrene and sometimes amputation. Controlling blood sugar and caring for the feet every day are the main ways to prevent serious problems.

EBO2 (EBOO) (also: EBOO, extracorporeal blood oxygenation and ozonation)

Extracorporeal blood oxygenation and ozonation: an ozone therapy in which heparinized blood is exposed to an oxygen/ozone mixture as it circulates outside the body and back. A 2005 review by the Siena group that developed the technique describes an apparatus that can treat up to 4,800 mL of blood in one hour, and a standard course of 14 one-hour sessions over 7 weeks. FDA regulation 21 CFR 801.415 calls ozone a toxic gas with no known useful medical application.

Effect size (also: effect estimate, effect measure, treatment effect)

A number that expresses how large a difference an intervention made between groups, such as a risk ratio or odds ratio, or a mean difference or standardized mean difference for measured outcomes. For ratio measures, a value of 1 means no difference between the groups; for difference measures, a value of 0 does.

Erratum (correction) (also: errata, correction notice, corrigendum, published erratum)

A notice a journal publishes to correct or add information in an article it has already published. The National Library of Medicine treats corrections, corrigenda, addenda, and partial retractions all as errata, does not distinguish errors made in publishing from errors in the science itself, and links each erratum notice to the original article in PubMed with the phrase "Erratum in".

Extracorporeal circuit (also: extracorporeal circulation, ex vivo circuit, extracorporeal blood system)

The tubing and devices that carry a patient's blood outside the body and back. In FDA's description of a hemodialysis system, blood flows through the tubing of the extracorporeal blood system to the dialyzer and returns through more tubing to the patient, and that system includes pumps, pressure monitors, air foam or bubble detectors, and alarms to keep the blood moving safely.

FDA establishment registration and device listing (also: FDA registered, FDA registration, FDA certified, FDA registration certificate, device listing)

The yearly registration that businesses making or distributing medical devices for the US are generally required to file with the FDA, along with a list of their devices. FDA says the resulting entry in its database does not mean the business or its devices are approved, cleared, or authorized, and that it issues no registration certificates, so "FDA registered" or "FDA certified" on a website is not a sign of FDA review.

FDA warning letter (also: warning letter)

A letter in which the FDA notifies a company or person of what it believes are significant violations of federal requirements, such as problems with claims for what a product can do, poor manufacturing practices, or incorrect directions for use. The recipient is asked to respond within a set time, either with plans for correction or with its own reasoning if it disagrees. FDA posts warning letters on its website, and later responses or actions can change the status of the issues a letter raises.

Fibromyalgia (also: fibromyalgia syndrome, FMS)

A chronic condition that causes pain and stiffness all over the body, fatigue, and trouble sleeping, often with problems in thinking and memory. Its exact cause is unknown, though studies suggest people with it process pain differently. There is no specific test, so other causes have to be ruled out first, and treatment, which combines medicines, lifestyle changes, talk therapy, and complementary therapies, focuses on relieving symptoms.

G6PD deficiency (also: glucose-6-phosphate dehydrogenase deficiency, favism)

An inherited enzyme deficiency that leaves red blood cells poorly defended against reactive oxygen species, so infections, certain drugs, and fava beans can trigger red blood cell breakdown, called hemolysis. Many people with it never have symptoms and do not know they have it.

Gas embolism (also: air embolism, venous gas embolism, arterial gas embolism)

Gas, such as air, entering the bloodstream and blocking blood flow. Bubbles in a vein travel to the lungs and can obstruct the pulmonary circulation; bubbles in an artery, or ones that cross to the left side of the heart through a patent foramen ovale, can block flow to organs such as the brain. It is rare but can be fatal, most cases follow medical procedures, especially those involving access to blood vessels, and treatment can include hyperbaric oxygen.

Hemodialyzer (also: dialyzer, high-permeability hemodialyzer)

The filter of a dialysis system, in which blood flows through one compartment and dialysis fluid through another, separated by a semipermeable membrane that toxins and excess fluid cross. FDA classifies high-permeability hemodialysis systems as Class II devices intended as artificial kidney systems for kidney failure, fluid overload, or toxemic conditions; the regulation does not mention ozone therapy.

Hemofilter (dialysis-type filter) (also: dialysis filter, membrane filter, dialysis chamber)

A dialysis filter cartridge used in some versions of EBOO. In a 2023 paper on what it calls ozone dialysis, a California clinic describes a pump drawing blood from a vein in one arm into a cellulose triacetate dialysis chamber, where blood flows around tiny tubes while ozone gas flows the opposite way inside them, and then returning it through a vein in the other arm.

Hemoglobin (also: Hb, Hgb, haemoglobin)

The iron-rich protein in red blood cells that carries oxygen from the lungs to the rest of the body. A hemoglobin test, usually measured as part of a complete blood count, is often used to check for anemia, a shortage of healthy red blood cells. It is a different test from hemoglobin A1C, which tracks average blood sugar.

Hemolysis (also: red blood cell breakdown, haemolysis)

The premature breakdown of red blood cells. When red cells are destroyed faster than the body can replace them, the result is hemolytic anemia. In G6PD deficiency, for example, infections, certain drugs, or fava beans can raise levels of reactive oxygen species until they damage red cells and trigger hemolysis.

Heparin (also: unfractionated heparin)

An anticoagulant, or blood thinner, that works by reducing the blood's ability to clot. It is used to prevent clots in people with certain medical conditions or during certain medical procedures, to stop clots that have already formed from growing, and to keep catheters from clotting. It is given into a vein or deep under the skin, not into a muscle.

Hollow-fiber membrane (also: hollow fiber membrane, fiber cartridge)

A membrane made as very thin hollow fibers, used as the gas-exchange surface of membrane oxygenators. Oxygenator fibers described in a 2024 review include ones 200 micrometers across inside, made of silicone rubber, porous polypropylene, or polymethylpentene, and in most current oxygenators blood flows around the outside of the fibers. Clotting in the blood path or plasma leaking through the membrane can reduce gas exchange and make the device fail.

Hormesis (also: hormetic response, biphasic dose response, U-shaped dose response)

An adaptive response in which a moderate challenge, such as exercise, fasting, or a low dose of a chemical or radiation, leaves a cell or organism functioning better or better able to tolerate a later, more severe challenge. Researchers also call such effects a biphasic or U-shaped dose response, or preconditioning, the term behind oxidative preconditioning.

Hyperbaric oxygen therapy (HBOT) (also: HBOT, hyperbaric chamber, hyperbaric oxygen)

A treatment in which a person breathes pure oxygen inside a special chamber where the air pressure is raised above normal, which helps the lungs take in more oxygen. FDA classifies HBOT chambers as Class II devices cleared through the 510(k) process and has warned providers about reports of serious injuries and deaths with their use. It involves breathing oxygen, not ozone, so it is a different treatment from EBO2 and from the 10-pass method some clinics call hyperbaric ozone.

In vitro (also: in vitro study, laboratory study, test-tube study)

Describes research done in the laboratory, outside a living body, for example on cells or a blood sample in a dish or tube. The opposite is in vivo, meaning in a living body. An in vitro result shows what happened under laboratory conditions, not what happens in a patient.

Informed consent (also: consent form, written informed consent)

The process in which a health care provider explains a patient's condition and a proposed treatment, including what happens during it, its risks and how likely they are, how likely it is to work, whether it can wait, and the other options, before the patient decides. Signing a form is one way to record consent, and a patient who understands the choices may refuse.

Investigational device exemption (IDE) (also: IDE, investigational device)

FDA permission to use an investigational device, or a marketed device for a new intended use, in a clinical study that collects safety and effectiveness data. The study needs an investigational plan approved by an institutional review board, and FDA must also approve the IDE when the device poses a significant risk. An IDE lets a device be shipped for research without meeting the rules that apply to devices in commercial distribution.

Lipoprotein apheresis (also: LDL apheresis)

A form of apheresis that lowers low-density lipoprotein (LDL) cholesterol and lipoprotein(a) in the blood. A 2024 American Heart Association scientific statement describes it as an underused add-on option for high-risk patients whose cholesterol stays high despite medication, particularly children and adults with familial hypercholesterolemia, and notes that US use covers only a fraction of its FDA-approved indications.

Long COVID (also: post-COVID conditions, post-acute sequelae of SARS-CoV-2 infection, PASC, long-haul COVID)

A chronic condition that follows infection with SARS-CoV-2, the virus that causes COVID-19, and is present for at least 3 months. It includes a wide range of symptoms and conditions that may improve, worsen, or persist for months or years. CDC notes that it is not one illness, that no approved laboratory test can show symptoms are due to it, and that there are no approved treatments.

Lyme disease (also: Lyme borreliosis, Borrelia burgdorferi infection)

A bacterial infection spread to people by the bite of infected blacklegged ticks, caused in the United States by Borrelia burgdorferi and, rarely, Borrelia mayonii. Typical symptoms are fever, headache, fatigue, and a characteristic rash called erythema migrans; if untreated, the infection can spread to the joints, heart, and nervous system. It is most common in the Northeast, mid-Atlantic, and upper Midwest.

MAH treatment cycle (also: MAH session, autohemotherapy cycle)

One round of major autohemotherapy, in which a batch of about 200 mL of the patient's blood is mixed with an oxygen/ozone gas mixture outside the body and returned. In the 10-pass method, as described in a 2022 paper co-written by its pioneer, each round is called a pass: one pass with 200 mL of gas at 70 µg/mL delivers 14,000 µg of ozone, and ten passes take about an hour.

Major autohemotherapy (MAH) (also: MAH, major ozonated autohemotherapy, major autohaemotherapy)

A form of ozone therapy in which, as described in a 2022 paper co-written by the pioneer of the 10-pass method, around 200 mL of a patient's blood is mixed with ozone and then returned to the same patient by gravity. The paper says it was first described in 1954. A higher-dose version that draws, ozonates, and returns blood ten times in one session is known as 10-pass ozone.

MAUDE database (also: MAUDE, Manufacturer and User Facility Device Experience database, medical device report, MDR)

The FDA's public database of medical device reports (MDRs) of adverse events, filed by manufacturers, importers, and device user facilities, which are required to report, and by voluntary reporters. FDA cautions that a report does not by itself show the device caused the event, and that the data cannot establish how often events happen, because events are under-reported, reports can be inaccurate, and causes often go unverified.

Medical ozone generator (also: ozone generator)

A device that makes ozone from medical oxygen at the point of use, since ozone made this way has to be used immediately; ozone is about 3% of the resulting gas mixture. Ozone-therapy researchers write that ozonated autohemotherapy was done empirically from 1970 to 2000, partly because generators were imprecise, and that generators with photometers able to measure the ozone concentration accurately became available by 1998.

MedWatch (also: FDA MedWatch, FDA safety reporting program)

The FDA's medical product safety reporting program for health professionals, patients, and consumers. It takes reports from the public about problems with FDA-regulated products, including prescription and over-the-counter medicines, biologics such as blood components, and medical devices, and FDA uses it to publish safety alerts when appropriate.

Meta-analysis (also: meta analysis, pooled analysis)

The statistical combination of results from two or more separate studies. It can make an estimate more precise, answer questions single studies did not pose, and help settle conflicting findings, but variation between studies, called heterogeneity, has to be considered, and the result can be very misleading if the review behind it neglects steps such as selecting studies carefully and considering their risk of bias.

Methemoglobinemia (also: MetHb, methemoglobin)

A blood disorder in which too much of the blood's hemoglobin takes an altered form, methemoglobin, that still picks up oxygen but does not hand it on well to the tissues. Some people inherit it, but it is more often acquired after exposure to certain medicines, chemicals, or foods, such as some anesthetics and antibiotics and the nitrites used to preserve meat. Bluish skin, called cyanosis, is a common sign.

Minor autohemotherapy (also: small-volume autohemotherapy, minor ozonated autohemotherapy)

A small-volume form of ozonated autohemotherapy. As described by ozone-therapy researchers Bocci, Zanardi, and Travagli (2011), usually 5 mL of the patient's blood is mixed vigorously with an equal volume of oxygen/ozone gas for about a minute and immediately injected, with the gas foam, into a buttock muscle, rather than the 100 to 225 mL reinfused into a vein in major autohemotherapy.

Misbranding (also: misbranded, misbranded device)

A violation of the Federal Food, Drug, and Cosmetic Act in which a drug's or device's labeling is false or misleading, leaves out required information or adequate directions for use, or recommends a use that is dangerous to health. A device is also misbranded if it is sold without FDA concurrence on a required 510(k) submission.

Multiple sclerosis (MS) (also: MS)

A disease of the brain and spinal cord in which damage to myelin, the protective coating around nerve cells, slows or blocks messages between the brain and body. Its exact cause is unknown; many believe it is an autoimmune disease in which the immune system attacks myelin. Symptoms vary and can include vision problems, weakness, numbness, fatigue, and trouble with balance; in the most common type, flare-ups alternate with periods of recovery.

Mycotoxins (also: mycotoxin, mold toxins)

Toxins made by certain molds and fungi that can grow on crops such as grains, dried beans, dried fruits, and coffee, generally during production and storage. Eating food with high levels can make people sick, and regularly eating foods with aflatoxins, one group of mycotoxins, can raise the risk of liver cancer. FDA monitors the food supply for several mycotoxins.

Narrative review (also: narrative literature review, traditional review)

A review article in which authors summarize and interpret research on a topic without the predefined protocol, thorough search, and transparent selection criteria of a systematic review. Narrative reviews can offer an expert's perspective, but their choice of studies can be selective: in one comparison, narrative reviews of the same studies reached different conclusions, and such reviews are not considered rigorous evidence.

Nrf2 pathway (also: NFE2L2, nuclear factor erythroid 2-related factor 2, Keap1-Nrf2 pathway)

A cell signaling pathway centered on the protein Nrf2 that regulates cells' protective response to stress caused by reactive oxygen species. Normally a partner protein, Keap1, marks Nrf2 for breakdown; when Nrf2 is active, it binds to antioxidant response elements in DNA and switches on protective genes. Raising Nrf2 activity can protect cells from oxidative stress, but it can also help cancer cells survive and multiply.

Off-label practice (also: off-label use, unapproved use)

Using an FDA-approved or FDA-cleared drug, biologic, or device for a use that is not included in its FDA-required labeling, which FDA calls an unapproved use. FDA says health care providers generally prescribe and use such products for unapproved uses when they judge the use medically appropriate for a particular patient. The idea applies only to products that have satisfied FDA's premarket requirements, such as a device with premarket approval, 510(k) clearance, or De Novo authorization.

Oxidative preconditioning (also: ozone preconditioning, hormetic stimulus)

The idea that a moderate, controlled oxidative stress makes cells develop an adaptive response, switching on their antioxidant defenses. In a 2011 review, ozone-therapy researchers Sagai and Bocci proposed that ozone therapy may work this way: moderate oxidative stress from ozone would activate Nrf2 and the production of antioxidant enzymes, while severe oxidative stress instead drives inflammation and tissue injury.

Oxidative stress

An imbalance between oxidants and antioxidants in favor of the oxidants, which disrupts redox signaling and control in cells or damages molecules. A 2015 review of the concept notes that the body's main antioxidant defense comes from antioxidant enzymes rather than small-molecule antioxidant compounds, and warns that the term is sometimes used loosely, without a clear link to the underlying chemistry.

Ozonated saline (also: ozonated normal saline, ozone saline infusion)

Saline treated with ozone and given as an intravenous infusion. Ozone-therapy researchers Bocci, Zanardi, and Travagli (2011) wrote that no comparative clinical studies had tested claims that it works like major autohemotherapy, noted that oxidative DNA damage had been found in patients' white blood cells after such infusions, and concluded that its use remains a constant danger.

Ozone (O3)

A gas that the FDA regulation 21 CFR 801.415 describes as toxic, with no known useful medical application in specific, adjunctive, or preventive therapy. The regulation says its main effect on the body is irritation of the mucous membranes, that breathing it in can irritate the lungs enough to cause pulmonary edema, and that to kill germs it must be far more concentrated than people can safely tolerate.

Ozone concentration, µg/mL (also: ozone dose)

The amount of ozone in each milliliter of the oxygen/ozone gas mixture, usually reported in micrograms per milliliter. The mixture is mostly oxygen with a small fraction of ozone, and ozone-therapy papers state the doses used to treat blood in these units.

Ozonides (also: ozonide, Criegee ozonide)

Compounds formed when ozone reacts with unsaturated fatty acids; the form made in the absence of water is called a Criegee ozonide. Ozone-therapy researchers list ozonides among the lipid ozonation products, along with hydroperoxides and aldehydes, that form as ozone reacts with fats, and propose that these products and hydrogen peroxide, rather than ozone itself, carry its effects in the body.

P value (also: p-value, statistical significance, statistically significant)

The probability of getting a result at least as large as the one observed if there were really no effect, the so-called null hypothesis. A very small P value means the result is unlikely to be due to chance alone, and values below 0.05 are often called statistically significant. A P value does not show whether an effect is large enough to matter, and a lack of evidence of an effect is not evidence that there is none.

Peer review (also: peer-reviewed, refereeing)

The process in which a journal sends a submitted manuscript to experts in the same field, who judge its validity, significance, and originality and suggest improvements before the editors decide whether to publish it. It is meant to filter out weak work and raise the quality of what is published, but it has been criticized as slow, open to bias from editors and reviewers, and a poor screen against plagiarism.

Peripheral artery disease (PAD) (also: PAD, peripheral arterial disease)

Narrowing of arteries outside the heart, most often those supplying the legs, caused by atherosclerosis, the buildup of plaque made of fat and cholesterol. Reduced blood flow can cause leg pain when walking and slow-healing sores and, if severe, tissue death that can lead to amputation, though many people have no symptoms. Smoking is the main risk factor, and PAD raises the risk of heart attack and stroke.

Placebo (also: placebo control, dummy treatment)

A pill or liquid that looks like the treatment being tested but has no treatment value from active ingredients. A clinical trial can assign some participants to a placebo, or to another control, so that the effects of the real treatment can be measured against it.

Plasmapheresis / therapeutic plasma exchange (also: therapeutic plasma exchange, TPE, plasma exchange)

A form of apheresis in which plasma is separated from the blood cells, by centrifuge or membrane, and removed, taking with it most plasma components, including antibodies and clotting factors; albumin or saline replaces it. A 2023 review reports evidence from many randomized trials supporting it as a first-line treatment for myasthenia gravis crisis and acute Guillain-Barré syndrome.

Post-treatment Lyme disease syndrome (PTLDS) (also: PTLDS, chronic Lyme disease, chronic Lyme, post-Lyme syndrome)

CDC's term for prolonged fatigue, body aches, or difficulty thinking that some people have after antibiotic treatment for Lyme disease; its cause is unknown. CDC discourages the term "chronic Lyme disease" because it implies an ongoing infection, says more antibiotics are unlikely to help, and notes that long-term antibiotic use has been linked to serious, even deadly, complications. Most people improve over time, though it can take months.

Premarket approval (PMA) (also: PMA, FDA-approved device)

The FDA's most stringent review for medical devices, required for most high-risk (Class III) devices, such as those that support or sustain human life. The maker must submit sufficient valid scientific evidence, including data from clinical investigations, that the device is safe and effective for its intended use, and must receive FDA approval before selling it. This is the device route that ends in approval; a 510(k) ends in clearance instead.

Preprint (also: preprints, unreviewed manuscript)

A complete, public draft of a scientific paper, usually written in the style of a journal article but not yet peer reviewed. Scientists post preprints to share results faster, establish priority, get feedback, and offset publication bias. A preprint is not the final version of the work, so its content can still change.

Publication bias (also: non-reporting bias, reporting bias, file drawer problem)

Bias that arises when whether research is published depends on the nature and direction of its results. Cochrane reports convincing evidence that results that are not statistically significant and are unfavorable to the treatment being tested are less likely to be published than significant ones, so systematic reviews find them less easily. Cochrane calls the wider problem non-reporting bias.

Randomized controlled trial (RCT) (also: RCT, randomized trial, randomised controlled trial)

A study in which participants are assigned by chance either to the treatment being tested or to a comparator, such as another treatment. Done properly, random assignment stops known and unknown factors that predict the outcome, such as how sick someone is, from deciding who gets which treatment, so on average each group starts with the same prognosis.

Reactive oxygen species (ROS) (also: ROS, oxygen radicals)

Reactive, oxygen-containing molecules such as superoxide, hydrogen peroxide, and the hydroxyl radical. The body makes them during normal oxygen use and exercise and keeps them in check with antioxidants; they can be toxic but also act as signals that help regulate genes. Ozone-therapy researchers describe ozone reacting with fatty acids in blood to form ROS, including hydrogen peroxide, which they call one of ozone's two main messengers.

Recall classes (Class I, II, III) (also: FDA recall, device recall, Class 1 recall, Class 2 recall, Class 3 recall)

A recall is an action a company takes, on its own initiative, at FDA's request, or by FDA order, to remove a product from the market. FDA ranks recalls by hazard: Class I means a reasonable probability of serious harm or death; Class II means possible temporary or medically reversible harm, or a remote chance of serious harm; Class III means harm is unlikely. Recall classes are separate from the Class I, II, and III risk classes of medical devices.

Rectal or vaginal ozone insufflation (also: rectal ozone, vaginal ozone, ozone enema, rectal insufflation)

Introducing an oxygen/ozone gas mixture into a body cavity. Ozone-therapy researchers Bocci, Zanardi, and Travagli (2011) describe rectal insufflation of 200 to 300 mL of gas at up to 35 µg/mL and call its effective dose unpredictable because of gas loss and bowel contents; for infections, 50 to 200 mL at 10 to 15 µg/mL can be insufflated into the vagina, urethra, or bladder.

Red blood cell (also: RBC, erythrocyte, red cell)

The blood cell that carries oxygen from the lungs to every cell in the body, using the iron-rich protein hemoglobin it contains. Red blood cells are made in the bone marrow, and a red blood cell (RBC) count, almost always done as part of a complete blood count, measures how many are in the blood.

Retraction (also: retracted article, retraction notice)

The withdrawal of a published article, announced in a notice by its authors, their institution, or the journal editor, for reasons such as pervasive error or data that cannot be substantiated or reproduced. PubMed marks retracted articles and does not distinguish honest error from misconduct. Before deciding, an editor may publish an expression of concern while the article's integrity is investigated.

Sham procedure (also: sham, sham surgery, sham treatment, placebo procedure, sham control)

An imitation of a procedure that mimics the real one but leaves out the element believed to produce its effect, used as the comparison in a trial so participants cannot tell which they received. In a 2014 systematic review of 53 surgical trials with a placebo arm, patients in that arm improved in 39 trials, and in about half the trials the real surgery did no better than the imitation.

Sjögren's disease (also: Sjogren's disease, Sjögren's syndrome, Sjogren's syndrome, Sjogren syndrome)

A chronic autoimmune disease in which the immune system attacks the glands that make moisture, causing mainly dry eyes and dry mouth; it can also cause joint and muscle pain, dry skin, rashes, numbness, and lasting fatigue. Most people with it are women; it is most common in people in their 40s and 50s and in people with other autoimmune diseases such as rheumatoid arthritis or lupus. There is no single test for it, and treatment focuses on relieving symptoms.

State medical board (also: medical board, board of medicine, medical licensing board)

The state agency that licenses physicians to practice in that state and disciplines them, with sanctions that can include suspending or revoking a license. In the US, medical licensing is delegated to the states; boards describe their main goal as protecting the public, and discipline, including investigating complaints, is their most resource-intensive work.

Surrogate endpoint (also: surrogate marker, surrogate outcome)

A trial measurement used in place of a direct measure of how patients feel, function, or survive, because it is expected to predict that benefit, as lower blood pressure stands in for fewer strokes. FDA treats a surrogate as validated only after extensive evidence, usually including clinical trials, shows it reliably predicts the benefit; candidate surrogates are still under evaluation.

Systematic review (also: systematic literature review)

A review that tries to collect all the research meeting criteria set in advance in order to answer a specific question, using methods that are stated explicitly and chosen to reduce bias. The question and the rules for which studies count are fixed first, every effort is made to find all relevant studies, and bias in the included studies is taken into account before conclusions are drawn.

Thiols (also: thiol, sulfhydryl groups, SH groups)

Molecules that contain a sulfhydryl (SH) group, which lets them act as antioxidants by stabilizing free radicals. The amino acids cysteine and methionine are dietary thiols that the body uses to make glutathione, a major internal antioxidant, and a low ratio of reduced to oxidized glutathione is read as a sign of oxidative stress.

Ultrafiltration (also: ultrafiltration coefficient, Kuf)

Removal of water from blood, along with some dissolved substances, by pushing it across a semipermeable membrane, the way a dialysis filter takes off excess fluid. FDA's rule for high-permeability hemodialyzers rates them by an ultrafiltration coefficient, the milliliters of fluid passed per hour for each millimeter of mercury of pressure, and requires an ultrafiltration controller or other control to prevent fluid imbalance.

Venous access (also: IV access, peripheral line)

Placing a needle or catheter into a vein so that blood can be drawn out or returned. In a 2023 paper on ozone dialysis, a form of EBOO, a California clinic describes giving each patient one 20-gauge intravenous catheter in each arm, one for blood to flow out and one for its return.

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EBO2 (EBOO) glossary