In today’s clinical and diving hyperbaric chambers, acrylic windows with PVHO-1 defined standard geometries and design criteria are used.1 Acrylic window shapes vary with chamber type and the window requirement of the specific chamber type.
Determining the best interventions, including dressing selection, for patients and their wounds requires looking at the situation holistically. Creating the treatment plan for a chronic wound is dependent upon many diverse patient, wound, economic, and social considerations. The dressing selection goes beyond simply choosing a product to cover the wound. Detailed assessments of the patient and wound should drive the components of goal-directed wound care. The health-care provider must determine the etiology of the wound, patient comorbidities that may impair the wound healing processes (e.g. diabetes and blood glucose levels), nutrition/hydration status, systemic and local tissue oxygenation, and patient/family concerns such as pain and odor issues. Each of these factors contributes to creating an individualized plan of care for choosing the most appropriate products and interventions.
Analysis of hyperbaric facility risks is a difficult process. It begins with identifying the hazards in a hyperbaric facility. These hazards could be from a variety of sources: equipment related (e.g. loss of power, loss of gas supply, control system malfunction); operational (e.g. untrained or unprepared staff); medical (e.g. pressure injuries, medical complica- tions); and environmental (e.g. contaminants, external disaster). The actual risks associated with a hazard depend on the probability, frequency, and severity of the potential losses.
Hyperbaric emergency procedures usually address a variety of problems ranging from mechanical malfunction to medical complications—important events that do not seem to share a common trait but cover a wide range of situations. Such a variable group of events must be discussed in a broad context. This chapter will discuss emergency pro- cedures within the framework of the entire hyperbaric safety program. In this broader context, events that may or may not be emergencies belong together. That is why this dis- cussion will replace the term “emergency procedure” with the term “contingency plan.”
A consensus document by Keast et al. reviewed clinically useful wound measurement approaches. This evidence-based document provided an overview of principles and practice regarding chronic wound assessment in a simple mnemonic format. The text articulated effective management of a nonhealing wound based upon:
Various theories have been proposed to explain why some wounds become chronic and non-healing. Although the complete answer is not yet available, a great deal has been learned in recent years that sheds light on this phenomenon.
APPROACH TO THE CRITICALLY ILL PATIENT
In the past several years, there has been rapid growth in the number of clinical hyperbaric facilities, due in part to the availability of the monoplace, or single-person, hyperbaric chamber and the proliferation of outpatient wound care centers. Monoplace chambers are relatively inexpensive, require fewer personnel, and require less space to operate and maintain than multiplace (walk-in) chambers. Another advantage of the monoplace over the multiplace chamber is that attendants need not enter the hyperbaric chamber with the patient. However, some hyperbaric physicians express concerns about treating unstable or critically ill patients in the monoplace chamber, because of the lack of “hands-on” care during hyperbaric exposure, the lack of suitable equipment for optimal patient care, and the limitations of treatment pressures to 3 atmospheres absolute pressure (ATA). We have found that with a well-trained staff and the availability of appropriate equipment, critically ill patients can be treated safely in the monoplace chamber. We, and others, have presented monoplace chamber use in critically ill patients. Anyone who anticipates treating critically ill patients in a monoplace chamber should be familiar with this work.
Adequate wound perfusion and its delivery of oxygen to the healing tissues is fundamental to wound healing as just explained. Revascularization invariably is the first intervention considered to achieve this goal. Hyperbaric oxygen all too often is not considered in the management. In addition, other interventions can improve perfusion-oxygenation. These include edema reduction, improvement in cardiac function through medical management, and enhanced blood rheology using pharmacological methods. In contrast to the other four treatment strategies where typically a single technique is utilized, the methods to improve the perfusion-oxygenation strategy are complimentary, and typically two or more techniques are employed simultaneously.
The second source of information regarding perfusion-oxygen needs for wound healing arises from indirect information . It is obvious that markedly increased blood flow and oxygen availability are required to heal a wound and control infection.(19) Perfusion and oxygen requirements are minimal for noncritical tissues that do not have wounds or infections because they are in a steady-state, resting status. An example of this would be the feet of the patient with advanced peripheral artery disease. If a relatively minor wound occurs in one foot, healing may not occur, and a lower limb amputation becomes necessary. In contrast, in the opposite limb that does not have a wound, but perfusion is equally poor, the foot is not immediately at risk for an amputation.
