INTRODUCTION

A hyperbaric and hyperoxic environment creates numerous considerations for the use of drug therapies within it. Physiologic changes to the body from hyperbaric oxygen therapy (HBOT) may lead to pharmacokinetic changes in drug disposition.  In addition, HBOT acting as a drug can interact and enhance or lessen the physiologic effect of the drug. Most drugs will not interact unfavorably with oxygen. Unless specific contraindications or precautions have been addressed, it is generally safe to assume a medication can be used. Significant known exceptions and their evidence along with implications of hyperbaric oxygen will be discussed.[1]

Pharmacodynamic interactions result in modification of the pharmacologic effect of the drug after administration. These interactions will increase or decrease the effects of oxygen or the drug.[1]

DRUGS INCOMPATIBLE WITH HYPERBARIC OXYGEN DUE TO ENHANCED DRUG TOXICITY

Antineoplastic Drugs

Bleomycin Sulfate (Blenoxane®, Blenomax®)

• Bleomycin is a polypeptide which fights against a number of tumors. The exact mechanisms of action of this drug are not clear; however, its cytotoxic effects are likely mediated through inhibition of cell cycle progression and the synthesis of DNA and protein.
• The primary dose-limiting toxicity of Bleomycin is the development of pulmonary toxicity ranging from radiographic changes to pneumonitis and fatal pulmonary fibrosis. 
• Controversy has surrounded the use of supplemental oxygen administration and perioperative patients who have received Bleomycin chemotherapy since 1978 due to oxygen-related risk to severe pulmonary complications.[2]
• Despite the theoretical risk, there are no articles specifically stating that HBO should be prohibited after bleomycin administration. As late as 2008, prior bleomycin remained an absolute contraindication to HBO therapy.[2]
• It is felt that as long as the patient has no signs of pulmonary compromise from fibrosis, and it has been over three months since he or she was treated with bleomycin, his or her exposure to bleomycin should not be a health factor.[2]
• If there is any question of pre-existing pulmonary disease, establish a baseline for pulmonary function with spirometry, diffusing capacity of the lungs for carbon monoxide (DLCO) and imaging and monitor for adverse changes during HBOT.[2]
• History of Bleomycin therapy may be considered as a relative contraindication to hyperbaric oxygen therapy.[1]

Cisplatin (Cisplatin®, Platinol®)

• Cisplatin has been used for a number of years in a variety of cancer treatment protocols.
• The therapeutic benefit of this drug is realized through its ability to inhibit DNA synthesis affecting fibroblast production and collagen synthesis. 
• Concomitant use of Cisplatin is a relative contraindication in patients who suffer from chronic, non-healing wounds and should not be considered for HBOT due to diminished wound healing. 
• In a life-threatening situation such as cerebral arterial gas embolism (CAGE) or gas gangrene, wound healing concerns are overridden by the emergency indication.[1]

Doxorubicin (Adriamycin®, Doxil®, Rubex®)

• Doxorubicin is an antineoplastic agent which interferes with DNA and protein synthesis.
• This drug is widely distributed in the body but has particularly high concentrations in the heart, liver, and kidneys.
• Adverse reactions such as cardiac dysrhythmias, acute left ventricular failure, and irreversible cardiomyopathies have been reported.
• Extravasation of this drug typically results in significant tissue damage.
• Given the lack of strong evidence and possibility of harm, HBOT and doxorubicin should be avoided in combination. Some recommend at least 3 days go by between the last doxorubicin dose and the initiation of the course of HBOT.  [1]

DRUGS DECREASING TOLERANCE TO OXYGEN TOXICITY

Narcotic Analgesics

• Narcotic analgesics may increase the risk of central nervous system (CNS) oxygen toxicity.
• In higher dosages, these drugs may cause respiratory depression resulting in carbon dioxide retention. This hypercapnea promotes CNS vasodilatation and increases oxygen delivery to the brain.  [1]

Thyroid Replacement (Synthroid®, Levoxyl®, Cytomel®)

Glucocorticoids

• Corticosteroids (Deltasone®, Decadron®, Solu-Medrol®, Solu-Cortef®)
• • Corticosteroids increase the risk of oxygen toxicity. 
  • Careful monitoring of the patient who is receiving large doses of steroids is necessary and prophylactic anticonvulsants may be necessary along with frequent air breaks. [1]

Sympathomimetic Amines - Dopamine (Intropin®) - Dobutamine (Dobutrex®) - Epinephrine (Adrenalin)

• Drugs that increase sympathetic stimulation may increase the suceptibility to oxygen toxicity by similar means to enhanced metabolic rate.
  
• Epinephrine was noted to increase pulmonary and CNS oxygen toxicity as early as the 1950’s. The mechanisms of this enhanced toxicity are not well understood; however, this must be given due consideration in the critical care setting where adrenergic agents are commonly utilized. [1]

Central Vasodilators

• Acetazolamide (Diamox ®)
  

• • Acetazolamide has carbonic anhydrase-inhibiting effects in humans leading to retention of carbon dioxide which promotes vasodilation and increases cerebral blood flow. This enhances oxygen delivery and decreases the time to oxygen toxicity. 
  • It also has diuretic effects and is commonly used for prophylaxis against high altitude sickness.
  • Through its CNS vasodilatory effects and consequent enhanced CNS oxygen delivery, the risk for oxygen toxic seizures is increased.
  • HBOT pressures should be limited to 2.0 ATA in this setting. Addition of air breaks should also be considered. [1]
• Mafenide Acetate (Sulfamylon ®)
• • A sulfonamide antimicrobial creme that inhibits the growth of a variety of microbial organisms
  • It has carbonic anhydrase-inhibiting effects in humans leading to retention of carbon dioxide which promotes vasodilation and increases cerebral blood flow. This enhances oxygen delivery and decreases the time to oxygen toxicity. 
  • It is recommended that this cream be removed from any patient entering the hyperbaric chamber.
  • Silvadene (Silver Sulfonamide) is the more common, safer alternative in the hyperbaric chamber. [1]

Opiod Analgesics

• Will enhance the risk of oxygen toxicity via CO2 retention, leading to central vasodilation similar to carbonic anhydrase inhibitors
• Depress respiration by reducing the reactivity of the medulla to CO2 leading to a rise in arterial PCO2 causing the blood vessels of the brain to dilate.  Due to the increased blood flow, the amount of dissolved oxygen rises in the brain tissue. This rise speeds the development of oxygen convulsions.
• Clinicians should monitor patients closely, and if respirations are noted to be decreased, the patient should be reminded to take deep breaths to ventilate and reduce the CO2 levels. [1]
  

Hyperthermia

• Elevation in temperature and metabolism leads to an increased susceptibility to oxygen toxicity.

DRUGS INCREASING TOLERANCE TO OXYGEN TOXICITY

Vitamin E (Alpha Tocopherol)

• Acts as an antioxidant and scavenges free radicals formed by oxygen
• Some hyperbaric clinicians recommend a pretreatment dosage of 400 units p.o. per 90-minutes of oxygen breathing. [1]

Propranolol

• A beta-adrenergic blocker that has good penetration into the central nervous system. 
• While propranolol is not recommended as a seizure-preventing medication, those who are on it may be more resilient to demonstrating signs of toxicity. [1]

Tromethamine (THAM)

• A buffering agent that will generate bicarbonate from carbonic acid instead of carbon dioxide. [1]

Chlorpromazine (Thorazine®, Largactil®) and Promethazine (Phenargan®)

• This medication showed a protective effect against CNS oxygen-induced seizures.
• Have similar mechanisms to sympatholytic properties of drugs
• Phenothiazines that have minimal effect on CNS vasomotor tone (those containing a piperazine side chain) should also have a similar benefit. [1]

CONSIDERATIONS FOR COMMONLY USED DRUGS

Anticonvulsants

• The use of anticonvulsants may be either prophylactic or for the treatment of seizures which do not stop when oxygen inhalation is terminated. 
• • If anticonvulsants are used prophylactically to suppress convulsions, it is critically important that the usual oxygen/pressure time limits be observed.  
• In the patient who is febrile, toxic from gas gangrene, taking steroids, or has an idiopathic-low seizure threshold, prophylactic administration of a suitable anticonvulsant may be indicated. [1]                             

Phenobarbital (Luminal®)

• Phenobarbital is efficacious in the prevention of CNS oxygen-induced seizures; however, respiratory depression must be considered which could lead to elevated levels of CO2, thereby increasing the risk of CNS oxygen-induced seizures. [1]

Benzodiazepines (Ativan®, Valium®, Librium®) Phenytoin / Phosphenytoin (Dilantin®)

• Benzodiazepines are effective as anticonvulsants and are generally well tolerated in the hyperbaric patient.
• Benzodiazepines are useful in treating patients with significant confinement anxiety and patients may require larger doses than would be expected.
• Monitoring of respiratory a mental status is recommended for patients who receive benzodiazepines prophylactically or during an emergency. [1]

Phenytoin

• Phenytoin has been widely used in epilepsy, but its efficacy in preventing oxygen convulsions is not well established
• Clinical experience dictates that its effect in stopping oxygen seizures can be substantial in the acute situation.  [1]

Disulfiram (Antabuse®)

• Inhibits ethanol oxidation to acetic acid and halts metabolism in the acetaldehyde stage.
• Causes flushing, nausea, and vomiting and is intended to deter the user from ingesting alcohol.
• The risk of using Disulfiram in the chamber is that it blocks the production of superoxide dismutase (SOD), a major protective enzyme against oxygen toxicity.
• Initially, animal studies showed promising results with the use of Disulfiram for the prevention of both pulmonary and central nervous system oxygen toxicity.
• This protective effect proved to be dramatic even with oxygen exposures as high as 6 atmospheres absolute (ATA). 
• Theoretically, Disulfiram may be protective for single hyperbaric treatments but may enhance toxicity with multiple treatments.
• It is no longer considered a contraindication to HBOT. [1]

Insulin

• The effects of HBO2 on insulin activity are clearly potentiated. Blood glucose levels have consistently been shown to fall in diabetic patients who are undergoing HBOT with average drops in blood glucose levels between 21-51 milligrams per deciliter. 
• Insulin requirements in diabetics may change rapidly, precipitating unexpected hypoglycemia. 
• HBO2 patients should be closely monitored for signs of hypoglycemia. Blood glucose levels must be checked prior to and immediately post HBOT.  
• Glucose supplementation with orange juice is suggested for pre-treatment blood glucose levels ranging 100-120 mg/dl. It is advised to hold HBOT for pretreatment blood glucose levels less than 100 mg/dl. [1]

Pseudoephedrine (Sudafed®)

• A front line decongestant for ear barotrauma
• At pressure depths of 3.0 ATA, studies showed an increase in anxiety scores, a decrease in verbal fluency scores, and an increase in mean heart rate. [3]
• Be aware that this medication can increase patient anxiety.[3]

Dimenhydrinate (Dramamine®)

• A commonly used antihistamine to control motion sickness
• At pressures of 3. ATA, studies showed an adverse effect on mental flexibility and memory but did not show an effect on heart rate.[3]

ANTIARRHYTHMIC AGENTS

Amiodarone

• An antiarrhythmic agent commonly used to treat supraventricular and ventricular arrhythmias.
• Tends to accumulate in several organs including the lungs.
• Pulmonary toxicity usually manifests as an acute or subacute pneumonitis, typically with diffuse infiltrates on chest x-ray and high-resolution CT.   [4]
• Results with HBOT and amiodarone are potentially worsening outcome of pulmonary oxygen toxicity with potentially permanent disability. However, there are no reports in the literature except in abstract form. The ultimate result of Amiodoarone in the face of HBOT is unknown. 

TRANSDERMAL DELIVERY SYSTEMS

• Transdermal medications are becoming more commonplace. While there have been no definitive studies, medication delivery through these systems is likely unaffected however consideration should be given to HBOT’s vasoconstrictive effect and the potential for temporarily altered absorption in a hyperbaric environment.
• Common types of medication patches include: nitrogylcerin, Clonidine, Narcotic (duragesic), Exelon (dementia), Estrogen, Testosterone, Oxytrol (incontinence), Scopolamine, Lidocaine, and Flector patch (diclofenac). 
• The potential risk of fire exists with the addition of adhesives and other hydrocarbon vehicles within the respective systems.
• Therapeutic warming wraps and patches consist of finely divided powdered iron, sodium chloride, and charcoal enclosed in a gas permeable pouch. The pouch is stored inside an airtight wrapper until ready to use. When the wrapper is opened, air diffuses through the pouch initiating an exothermic oxidation reaction between the iron and oxygen producing iron oxide and heat. Sodium chloride acts as a catalyst to speed up the rate of reaction. Charcoal is present to disperse the heat. The rate of warming is controlled by the amount of iron and oxygen to react. [5]
• As a general rule, it is felt prudent to remove the patches and use an acceptable alternative medication or mode of delivery.
• The final decision as to whether the medication patch may enter the chamber is between the HBOT Safety Officer and the Medical Director. 

IMPLANTABLE MEDICATION DELIVERY SYSTEMS

• A number of medication pumps are available to deliver medications on a continuous basis.
• The specific medication utilized must be considered in each case.
• The delivery device must be approved for use under hyperbaric conditions.
• Product specifications should be obtained from the manufacturer to determine if the device may be used.

OPERATIONAL CONSIDERATIONS

Providing HBOT in a safe manner is the primary objective with each and every treatment. The clinical team (physician, CHT, CHRN, etc) providing HBOT goes to great lengths to ensure patient safety with every treatment. A summary of operational considerations pertaining to adjunct HBOT is provided below:

Documentation by Certified Hyperbaric Nurse and Certified Hyperbaric Technician 

The certified hyperbaric technician (CHT) and certified hyperbaric nurse (CHRN) should maintain an accurate record of the care and related support services delivered during each patient’s course of hyperbaric oxygen therapy. The patient's chart is a legal document and as such, must reflect in meaningful terms the patient's condition, progress, and care rendered. The provider and nurse's notes must be concise, accurate, and support medical necessity for the treatment ordered. The notes must reflect responsibility for the care rendered. For details, see topic "Documentation: Hyperbaric Treatment Notes by the CHRN and CHT"

Daily treatment should include, but is not limited to the following: 

• Physician Order - confirm date and time of the order.
• Name of any Medication/ Drug given
• Dose, frequency and route of medication
• Patient Assessment (by the CHRN or CHT) 
• Pre-treatment Safety Check (by the CHRN or CHT)
• Documentation of the Treatment Log (by the CHRN or CHT)
• Physician Supervision (by the CHRN or CHT)
• Care Provided (by the CHRN or CHT)
• Plan of Care (by the CHRN or CHT, based on physician orders)

Safety Stop

Clinicians providing hyperbaric oxygen therapy go to great lengths to ensure patient safety with every treatment. We utilize processes and systems that have been developed within the field, in some cases through “near misses” and from standards set forth by The Joint Commission (TJC) and the Undersea and Hyperbaric Medical Society (UHMS).

In June of 2014, the UHMS Safety Committee released a position statement recommending the utilization of a safety “Stop” prior to the start of every hyperbaric treatment.  The position statement is available on the UHMS website:

“The Safety Committee of the Undersea and Hyperbaric Medical Society recommends that a Safety Time Out/Pause (STOP) be performed prior to the start of every hyperbaric treatment. A STOP should be completed regardless of multiplace or monoplace operations. A STOP will be performed in order to be compliant with safety goals, to combat complacency, and document completion of our unique safety practices. We recommend that the STOP be modeled after the timeouts performed before surgical procedures."

STOP Checklist

The practice of hyperbaric medicine is a procedure-oriented specialty. Each patient should have two identifiers verified and the patient should agree to the procedure. For the safety of patients and staff, we strongly encourage documentation of a Safety Time Out/Pause (STOP) protocol verifying the “Right Patient, Right Treatment and Right Safety.”  The STOP checklist should include:

• Signature and date on the completed STOP checklist (signed or initialed by two staff members prior to closing the door of the chamber)
• Treatment profile and staffing plan 
• Out of the chamber - confirmation that prohibited items were removed from the chamber (both monoplace and multiplace)
• Patient ground check (monoplace) 

The UHMS recommends that each hyperbaric facility and institution develop and implement a STOP protocol with these basic elements. For a basic template, refer to topic "Safety Time Out/Pause (STOP) Checklist". A more detailed protocol may be in order depending on the specific needs of the facility.

The UHMS Safety Committee position statement provides a structured approach to pre-treatment procedures. This statement is long overdue and should be taken one step further to include pre-hyperbaric treatment checklists.  Pre-treatment checklists have been employed for many years and include inspection and confirmation that Prohibited Items have been removed from the patient’s possession prior to initiation of the treatment.  Elements of the Safety STOP should be included in all pre-treatment checklists. 

In an article published on the NEJM Catalyst website, “Smartlists for Patients: The Next Frontier for Engagement?” Latif et al. identify that checklists work by providing information about who needs to act, what actions need to be taken, and how, where, and when each action should occur.[6] As such, customized patient-centered checklists have a wide range of applications, with the potential to improve patient education, pre-procedure planning, discharge instructions, care coordination, chronic care management, and plans for staying well. 

The question becomes, at what point is the inspection and verification of Prohibited Items documented?  Are you inspecting the patient, verifying, initiating treatment (descent) and then documenting?  If so, then utilizing a “STOP” prior to the initiation of descent should be implemented and utilized to ensure all pre-treatment safety checks are appropriately completed. 

Chamber Inspections

• Routine chamber inspections should be conducted to confirm chamber maintenance procedures and the safe operation of all equipment utilized during HBOT.
• To ensure the safety of the environment in the hyperbaric medicine facility, chamber inspections are to be performed routinely (i.e. daily, monthly, semi-annually, as needed). Processes and systems that meet standards set forth by The Joint Commission (TJC) and the Undersea and Hyperbaric Medical Society (UHMS) should be utilized, and elements that have been developed within the field (in some cases through “near misses”) may be incorporated. These processes and systems can be implemented through customized patient-centered checklists. Checklists have a wide range of applications, with the potential to improve patient education, pre-procedure planning, discharge instructions, care coordination, chronic care management, and plans for staying well. 
• For resources on chamber inspections, see topic "HBO Safety Inspections".

Prohibited Item(s), Assessment and Authorization 

• Wound dressings, devices, and other objects that go in the hyperbaric chamber with the patient may raise important safety concerns, including the production of heat, production of static electricity, production of flammable vapor, ignition temperature, and total fuel load. It is critical that clinicians understand which dressings, devices, and objects are prohibited, restricted or allowed inside a hyperbaric chamber during HBOT. 
• Frequently, questions arise in regard to what can be taken into the chamber. The NFPA 99 2012 edition, chapter 14 "Hyperbaric Facilities", provides the process for effectively managing patient care product(s) during HBOT.  The NFPA 99 2018 edition - 14.3.1.6.4.4 states “Physician and Safety Director approval to use prohibited items shall be stated in writing for all prohibited materials employed”. [7]
• Each hyperbaric facility should maintain an internal list of items that are approved for use, should be used with caution and should not be used in the chamber. An authorization form is required for items that should be used with caution. To facilitate assessment, clinicians might opt to utilize the Go-No-Go Risk Assessment Tool. The tool is an interactive process that enables hyperbaric technicians, Safety and Medical Directors to document the product information necessary to complete the risk assessment process. Upon completion of the process, the user will have the ability to print or email the document. In addition, clinicians can review lists of items that are approved for use, should be used with caution and should not be used in the chamber. See "Go-No-Go Lists / Prohibited Items" and "Go-No-Go : Frequently  Asked Questions".

Ancillary Equipment

All equipment utilized by the hyperbaric medicine facility is maintained through a program of regular preventative maintenance. The manufacturer maintains the hyperbaric chambers during the regularly scheduled service contract. Ancillary equipment (e.g. cardiac monitor leads, IV pumps) should be serviced by the Hospital's Biomedical Department and maintained in accordance with the recommendations of the manufacturer.  See topics "Ear Exam - Barotrauma" and "Ancillary Equipment" 

Air Breaks

• During HBOT, it is necessary to provide an alternative air breathing source. This may also be necessary to reduce the risk of central nervous system oxygen toxicity.  The air breathing system consists of an independent high-pressure air source, capable of providing flow that is sufficient to meet the patient's inspiratory demand. Air breathing systems may be provided by institutional gas outlet (wall outlet) or via portable "H" cylinders utilizing a diameter index safety system (DISS) regulator.  Delivery of the air break to the patient may be provided by disposable non-rebreather mask, demand valve and resuscitation mask or trach collar.  For purposes of infection control, masks should be single patient use and cleaned or replaced (per patient) as needed.
• While the use of air breaks to decrease the incidence of CNS oxygen toxicity has not been directly demonstrated, there is a large amount of published data on the cause of oxygen toxicity related directly to a combination of the level of FiO2 and time. As such, these air breaks limit the interval time exposure and are expected to decrease the risk of oxygen toxicity. [8]

Blood Glucose Level and HBOT

• It necessary to ensure that all patients who are currently being treated for irregular blood glucose levels do not experience a hypoglycemic event as a result of ongoing HBOT. Most studies suggest that blood glucose decreases in patients with diabetes who undergo HBOT. This decrease in blood glucose is estimated at 50 mg/dl. HBOT might not be as effective in patients with non-insulin dependent diabetes mellitus patients, compared to patients without diabetes. [1]
• If diabetes mellitus is present, blood glucose should be checked within 1 hour prior to treatment and immediately post-HBOT. The goal is to ensure that all patients who are currently being treated, do not experience a hypoglycemic event as a result of ongoing HBOT.  Hypoglycemia in the hyperbaric environment may present similar symptoms as oxygen toxicity, including but not limited to sweating, pale skin, shakiness, anxiety, tingling or numbness of the tongue or cheek. See section 'Blood Glucose Level and HBOT' in topic "Patient Care".

Oxygen Toxicity

• The hyperbaric staff should be skilled in reducing the potential for and management of oxygen toxicity for the patient receiving HBOT. 
• Central Nervous System (CNS) oxygen toxicity can occur in patients breathing oxygen at pressures of 2.0 ATA (atmosphere absolute) or greater. Convulsions may occur abruptly or may be preceded by other signs of central nervous system irritability. [1]  Early estimates of the seizure rate during therapeutic oxygen exposures at 2-3 ATA reported a convulsion incidence of about one per 10,000 therapies or 0.01%.[1]
• The hyperbaric physician will be notified immediately if a patient experiences signs or symptoms of oxygen toxicity during HBOT.

NURSING INTERVENTIONS

Nursing interventions that are relevant for adjunct HBOT are presented below. [9] For further information see topic "Nursing Interventions".

Knowledge deficit related to hyperbaric oxygen therapy and treatment procedures

• Assess and document the patient and/or family's understanding of purpose and goals of HBOT, procedures involved, and potential hazards of HBOT. Utilize the teach-back method to confirm patient understanding and identify and address barriers to learning. Involve an interpreter if indicated, apply age-specific teaching, consider cultural/religious factors, assess readiness to learn, and identify patient's expectations of treatment. 
• See section 'Knowledge deficit related to hyperbaric oxygen therapy and treatment procedures' in topic "Nursing Intervention"

Anxiety related to hyperbaric oxygen treatments or other medical problems 

• Assess the patient for a history of confinement anxiety and implement preventative measures as appropriate. It is important to reinforce to patient that someone will always be with them, and the staff are well trained for emergency procedures. Identify signs of symptoms of anxiety before and during HBOT such as:
• Patient states they are anxious
• Tense appearing facial/body posturing
• Complaint of nausea or diarrhea
• Feelings of being confined or smothered
• Defensive or argumentative attitude
• Hyperventilation
• Diaphoresis and hyperventilation
• Tachycardia
• Restlessness
• Sudden feeling of being hot
• See section 'Anxiety related to hyperbaric oxygen treatments or other medical problems' in topic "Nursing Intervention"

Potential for injury within the hyperbaric facility related to transferring the patient in and out of the chamber

• When transferring a patient that is being treated for Idiopathic Sudden Sensorineural Hearing Loss, comply with the facility's fall risk prevention policy.  Prior to transfer of the patient assess fall risk and safety precautions.  Communicate and involve patient with the plan of action and provide patient education regarding safety precautions.  Provide assistance with transfers as patient needs apply to ensure compliance with institutional/facility policy. 

Potential for injury related to fire within the hyperbaric chamber

• Fuel sources in an oxygen-enriched environment are an unavoidable circumstance of HBOT and include linens, equipment, dressings, and the patient.  The fire triangle consists of oxygen, fuel, and an ignition source(heat).  In HBOT an ignition source is needed to complete the fire triangle. This may occur due to a spark in the chamber. Follow facility fire prevention steps and NFPA chapter 14 probes for Class A and Class B hyperbaric chambers. HBOT teaching and consent should include the risks of fire in the chamber.  Provide the patient and family with written instructions regarding the risk of prohibited materials during HBOT.  Prior to each hyperbaric treatment, staff should perform and document the pre-treatment safety checklist. Ensure this has been performed and time-stamped prior to descent.  Patients receiving treatment for a compromised skin graft or flap may have surgical dressings that are ordered to remain intact.  A risk assessment per the Safety Director in collaboration with the Medical Director to determine if they may enter the chamber on a case by case basis. Safety measures should be initiated if the risk assessment allows for item to enter the chamber as well as completion of a prohibited item's authorization form signed by the Safety and Medical Directors.

Potential for injury related to changes in atmospheric pressure within the hyperbaric chamber

• Assess patient's and inside attendant's knowledge of ear clearing techniques and ability to equalize pressure. Collaborate with provider to assess tympanic membrane (TM) for suspected barotrauma prior to and after the first HBO treatment and per patient complaint.  Collaborate with the provider to describe and document observations including color and visibility of TM, presence of wax, blood/fluid/air and any hearing deficits or changes. Methods to equalize pressure in the middle ear during HBOT include: yawning, swallowing, jaw thrust, head tilt, Valsalva, Toynbee, Roydhouse, Frenzel, etc. Reinforce the importance of notifying the chamber operator immediately when pressure or fullness is felt in the middle ear.

Imbalanced nutrition/less than body requirements related to intake of nutrients insufficient to meet metabolic needs

• Patient's nutrient intake must be sufficient to meet basal needs and improve healing.  It is well documented that wound healing is impaired  without sufficient metabolic energy and nutrients. The patients baseline nutritional status should be assessed initiating adjunctive HBOT.  The need for nutritional supplementation should be coordinated with the primary care physician and/or referring service.  Provide nutritional education with consideration to the patient's needs and dietary preferences. For more information see topic: "Nutritional Screening for Wound Care and Hyperbaric Oxygen Therapy".

Potential for unstable blood glucose level related to hyperbaric oxygen therapy and disease pathology

• Literature notes hyperbaric oxygen therapy carries its own mechanism for increased glucose usage through oxygen-mediated transport of glucose into muscle cells and may also increase insulin sensitivity.  Prevention of acute hypoglycemia in the hyperbaric chamber is vital for patient safety.  Follow facility policy and procedure guidelines for pre and post-treatment glucose control.  Prior to treatment assess the patient's knowledge level, recent hypoglycemic events, and patient-specific symptoms of hypoglycemia.  Proper glucose control < 200mg/dL is vital for wound healing.  Consider timing of short and long-acting glycemic control medications when scheduling HBOT to avoid peak action time while at depth in the chamber 

CATEGORY A CONTINUING EDUCATION CREDIT

This topic has been reviewed and approved by the National Board of Diving and Hyperbaric Medical Technology (NBDHMT) for one (1) Category A Credit.

To claim the credit: 

• 1. Read the topic
• 2. Answer the examination and course critique questions.
• Take the quiz via SurveyMonkey 
• 3. Receive the certificate by e-mail. A passing score of 70% is required (please allow up to 8 business days for processing)

For more information on Category A continuing education credits see blog post " Hyperbaric Certification and Continuing Education for Technicians & Nurses".

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