Pilot study: Utility of long-wave infrared thermography as a correlate to transcutaneous oximetry for candidates of hyperbaric oxygen therapy.

Hyperbaric oxygen (HBO2 ) has been used as an adjunctive treatment for the care of advanced non-healing diabetic foot ulcers (DFUs). A patient's in-chamber transcutaneous oximetry measurement (TCOM) is currently the most effective predictor for response to HBO2 therapy but still excludes close to one in four patients who would benefit out of treatment groups when used for patient selection. Improving selection tools and criteria could potentially help better demonstrate HBO2 therapy's efficacy for such patients. We sought to identify if long-wave infrared thermography (LWIT) measurements held any correlation with a patient's TCOM measurements and if LWIT could be used in a response prediction role for adjunctive HBO2 therapy. To investigate, 24 patients already receiving TCOM measurements were enrolled to simultaneously be imaged with LWIT. LWIT measurements were taken throughout each patient's therapeutic course whether they underwent only standard wound care or adjunctive HBO2 treatments. A significant correlation was found between in-chamber TCOM and post-HBO2 LWIT. There was also a significant difference in the post-HBO2 LWIT measurement from 1st treatment to 6 weeks or the last treatment recorded. These initial findings are important as they indicate a possible clinical use for LWIT in the selection process for patients for HBO2 therapy. Larger studies should be carried out to further articulate the clinical use of LWIT in this capacity.

Blood glucose levels in diabetic patients undergoing hyperbaric oxygen therapy.

INTRODUCTION: To determine if hyperbaric oxygen (HBO2) therapy has an effect on diabetic blood glucose levels (BGL) and, if so, the extent of this effect. Also, to examine factors that exacerbate any observed effect. METHODS: This was a retrospective review of prospectively collected quality data on diabetics undergoing HBO2. Pre- and post-treatment BGL were recorded. Pre-treatment BGL ⟨120 mg/dL received glucose supplementation. Hypoglycemia was defined as BGL ⟨70 mg/dL. BGL ⟨90 mg/dL was included as an elevated hypoglycemia threshold. RESULTS: 77 patients representing 1,825 treatments were included for analysis. No patient had deleterious side effects or required emergency care. BGL decreased in 75.4% of treatments in this group, with a median decrease of 25 mg/dL (IQR=54 mg/dL; range of decreased 374 mg/dL to increased 240 mg/dL). A statistically significant greater percentage of treatments of patients with type 2 diabetes resulted in a decrease in BGL (1598 or 77.5%) compared to treatments of patients with type 1 diabetes (169 or 51.5%) (χ2(1, N=1767) =55.37, p⟨0.001). 1.1% of treatments had post-HBO2 serum glucose ⟨90 mg/dL, and 0.2% of treatments had post-HBO2 serum glucose ⟨70 mg/dL. The majority (70%) of patients with post-HBO2 BGL ⟨90 mg/dL were maintained on insulin alone (χ2(2, N=20) =12.4, p=0.002). Well-controlled diabetics (i.e., those with all BGLs within 50 mg/dL over all pre-HBO2 treatments) had no post-HBO2 BGL ⟨70 mg/dL or ⟨90 mg/dL. CONCLUSION: Our results suggest that HBO2 does not cause a clinically significant decrease in diabetic patient BGL. No patient in our study had deleterious side effects or required emergency care. We found that glucose level of ⟨90 mg/dL occurred more often in those who use insulin. Hyperbaric patients who exhibit consistent BGL values may represent a group who could be managed similarly to the non-diabetic population.

Use of in-chamber transcutaneous oxygen measurement to determine optimal treatment pressure in patients undergoing hyperbaric oxygen therapy.

INTRODUCTION: Hyperbaric oxygen (HBO2) therapy is used to promote healing in select problem wounds. Transcutaneous oxygen measurement (TCOM) can be used to predict the response of these wounds to HBO2, with in-chamber TCOM values shown to be the most predictive. We evaluated the use of in-chamber TCOM values to determine optimal treatment pressure. METHODS: A retrospective review was completed of patients undergoing HBO2 therapy for a lower-extremity wound and who had in-chamber TCOM. Data collected included TCOM values, treatment profile, and patient outcome. RESULTS: A total of 142 patients were identified. The overall results demonstrated healing in 59%, minor amputation (below ankle) in 11.3%, and major amputation (above ankle) in 16.2% of patients. 79.3% of patients at 2 atmospheres absolute (ATA) and 86.6% of patients at 2.4 ATA had transcutaneous oxygen pressure (TcPO2) values ≥250 mmHg. Among those with TcPO2 ⟨250 mmHg at 2 ATA, 41% attained TcPO2 ⟩250 mmHg at 2.4 ATA. Among those treated at 2 ATA the healing rate was 70.6% if TcPO2 ⟩250 mmHg, and 11.8% if TcPO2 ⟨250 mmHg (P⟨0.001). Among those treated at 2.4 ATA the healing rate was 33.3% if TcPO2 ⟩250 mmHg and 14.3% if TcPO2 ⟨250 mmHg (P⟨0.001). DISCUSSION: Determining optimal therapeutic pressure for patients undergoing HBO2 is important to maximize benefit and minimize risk. This study indicates that in-chamber TCOM can be used to select an individualized optimal treatment pressure in patients undergoing HBO2 for lower-extremity wounds, including diabetic foot ulcers. This may result in better utilization of HBO2 and better outcomes.

Effect of hyperbaric oxygen therapy on blood pressure in patients undergoing treatment.

INTRODUCTION: Hyperbaric oxygen (HBO2) therapy is generally safe and well tolerated. However, known side effects do exist. Elevation in the blood pressure of patients undergoing HBO2 therapy is a less defined potential side effect. We sought to better quantify effects of HBO2 on blood pressure (BP) in patients undergoing HBO2. METHODS: A retrospective chart review was performed on quality assurance data captured on all patients undergoing HBO2 between March 2012 and October 2015 at a large tertiary referral university hospital hyperbaric center. RESULTS: We identified 155 patients who received 3,147 hyperbaric oxygen treatments. For all treatments there was an overall increase in the median systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) following treatment. No statistically significant difference was found when comparing patients with and without hypertension. Calcium channel blockers (CCB) and beta-blockers (BB) were found to have an agonizing effect while ACE inhibitors (ACEI) were found to have a protective effect. The change in SBP was less with each additional treatment in patients undergoing more than one treatment. DISCUSSION: The current study demonstrates that absolute rises in blood pressure do occur as a result of HBO2 therapy. However, the extent of this effect is not large. BB and CCB had agonizing effects while ACEI had a protective effect. Finally, there was a protective effect with more treatments.

Patient Outcomes and Factors Associated with Healing in Calciphylaxis Patients Undergoing Adjunctive Hyperbaric Oxygen Therapy.

Calcific uremic arteriolopathy, also known as calciphylaxis, is a rare syndrome of small vessel calcification of unknown etiology causing painful, violaceous skin lesions that progress to form chronic non-healing ulcers and gangrene. Hyperbaric oxygen therapy (HBOT) can be used as adjunctive therapy in the treatment of these ulcers. However, due to paucity of cases, there is limited data on the clinical benefit of HBOT and identifying factors associated with healing. The purpose of this study was to determine patient outcomes and factors associated with healing in patients with calciphylaxis undergoing HBOT. A retrospective chart review was completed on patients who were diagnosed with calciphylaxis and had hyperbaric medicine consultation between May 2012 and January 2016. Clinical outcomes, demographics, risk factors, laboratory values, wound distribution, and HBOT profiles were collected and analyzed. We identified 8 patients. Out of 8 patients consulted for calciphylaxis, five were consented and underwent HBOT (2 males and 3 females). All had coexisting ESRD and Diabetes. All males were able to tolerate being in the chamber and received therapeutic treatments (at least 20 HBOT) with complete resolution of ulcers. HBOT was discontinued in one female due to an inconsistent biopsy report and two others due to death secondary to septic shock or respiratory arrest and severe uremia. Calciphylaxis is a devastating disease with a high mortality rate. Our results demonstrated a positive response to HBOT especially when receiving at least 20 treatments. A majority of calciphylaxis cases are females and indeed female gender has been cited as a risk factor for this disease. However, current literature has not conferred a relationship between gender nor the number of HBOT received and outcomes. Our results showed that males had a more favorable outcome provided they received at least twenty HBOT. Further prospective studies are needed to elucidate these outcomes.

Hyperbaric oxygen for the treatment of nonhealing arterial insufficiency ulcers.

There is limited data regarding hyperbaric oxygen's effectiveness in the treatment of nonhealing arterial insufficiency ulcers. This study was designed to analyze healing rates and amputation rates in patients who underwent adjunctive hyperbaric oxygen for a nonhealing arterial insufficiency ulcer. A retrospective chart review was completed on patients who underwent hyperbaric oxygen for arterial insufficiency ulcers that failed to heal despite standard treatment. Information collected included complete ulcer healing, amputation, and patient characteristics. There were 82 patients identified. A majority did not have diabetes (84.1%). The overall rate of healing was 43.9%. The overall major amputation rate was 17.1%. The amputation rate among those who healed was 0% compared to 42.4% among those not healed (p < 0.0001). Dialysis was predictive of major amputation (p = 0.03). Our findings suggest hyperbaric oxygen can play a role in management of arterial insufficiency ulcers that have failed standard treatment. The overwhelming majority of these patients did not have diabetes, which allows this study to be translated to patients with a primary arterial insufficiency ulcer. These results support the use of hyperbaric oxygen for select nonhealing arterial insufficiency ulcers that have failed standard therapy and the need for a prospective pilot study.

Middle ear barotrauma in hyperbaric oxygen therapy.

INTRODUCTION: Middle ear barotrauma (MEB) is a common complication of hyperbaric oxygen (HBO2) therapy. The purpose of this study was to determine the overall incidence of MEB and evaluate for differences in the incidence of MEB at different rates of compression (ROC). The study also sought to identify other potential risk factors for MEB. METHODS: A retrospective chart review was performed on patients undergoing HBO2 at an academic regional level 1 trauma center. The MEB overall incidence as well as incidence at different ROC were determined. RESULTS: 236 patients representing 4,981 treatments were analyzed. The overall incidence of MEB was 43.2%. There was no statistically significant difference in the incidence of MEB at different ROC. There was a statistically significant higher incidence of TEED 4 MEB in intubated patients (p < 0.0001). The vast majority of MEB was minor when considering severity based on overall lower TEED scores of 1 or 2 (84%). DISCUSSION: The overall incidence of MEB in this study is consistent with those previously reported. It is important to note that a vast majority of MEB was minor. This supports HBO2 as a safe treatment modality with minimal overall risk. The current study supports standardization of most treatment protocols to a ROC of 2 psi/minute.

Seizure incidence by treatment pressure in patients undergoing hyperbaric oxygen therapy.

INTRODUCTION: Hyperbaric oxygen (HBO2) therapy uses different maximum treatment pressures. A side effect of HBO2 is oxygen toxicity seizure. The purpose of this study was to determine the overall incidence of oxygen toxicity seizure and assess risk at different treatment pressures. METHOD: A retrospective chart review was performed on patients who underwent HBO2 at a university hospital and at an outpatient center. Statistical analysis was performed to determine overall incidence of seizure and identify risk factors including maximum treatment pressure. RESULTS: A total of 931 patients were identified representing a total of 23,328 treatments. The overall incidence of seizure was one in 2,121 treatments (five per 10,000). There were zero per 10,000 at 2.0 atmospheres absolute/atm abs (0/16,430), 15 per 10,000 at 2.4/2.5 atm abs (1/669) and 51 per 10,000 at 2.8 atm abs (1/197). There was a statistically significant difference for seizure between the different pressures (χ2 (2, 23,540) = 31.38, p < .001). DISCUSSION: The overall incidence of oxygen toxicity seizure in this study is consistent with recent reports. This study demonstrated a statistically significant increased risk of seizure with increasing treatment pressure. Treatment at higher pressure should be chosen based on demonstrable benefit with a clear understanding of increased risk with higher pressure.

Hyperbaric oxygen and dental extractions in irradiated patients: short- and long-term outcomes.

PURPOSE: Mandibular osteoradionecrosis (ORN) can occur in patients post-radiation therapy. This study assessed the incidence of ORN in the setting of adjunctive hyperbaric oxygen therapy (HBO2) and sought to identify risk factors that may predispose to its development. METHODS: A retrospective chart review was completed on patients with a history of radiation therapy to the head and neck who underwent HBO2 prior to and immediately following dental extractions between January 1, 1995, and December 31, 2005, in the hyperbaric medicine unit. RESULTS: The incidence of ORN in 40 patients immediately following completion of HBO was 0%. Available follow-up longer than six months after completion of HBO2 on 19 of these patients showed an incidence of ORN increased to 15.8%. None of the considered risk factors for development of ORN reach statistical significance. CONCLUSION: The incidence of ORN at the completion of HBO2 was less than previously reported incidences between 1.5%-4.2%. However, long-term follow-up indicated a much higher incidence of 15.8%. The difference in incidence of ORN immediately upon completion of HBO2 approximately two weeks after dental extractions compared to that at least six months later identifies a need for more long-term follow-up of these patients following their dental extractions.

Professional attitudes in regard to hyperbaric oxygen therapy for dental extractions in irradiated patients: a comparison of two specialties.

OBJECTIVES: Mandibular osteoradionecrosis (ORN) is a serious complication of radiation therapy. The current use of hyperbaric oxygen therapy (HBO2) to prevent ORN when dental extractions are performed has been called into question. We sought to determine the current acceptability and confidence in this treatment by practitioners from two different specialties. METHODS: We surveyed both hyperbaric medicine physicians and radiation oncologists regarding their views on the use of HBO2 for the prevention of ORN. Separate web-based anonymous surveys were sent via email invitation. These two groups were compared, including statistical analysis using the chi-square test when appropriate. RESULTS: 175 radiation oncologists and 118 hyperbaric medicine physicians participated. Among those not recommending HBO2, lack of evidence was cited by 52% of radiation oncologists and 38% of hyperbaric medicine physicians (chi2 = 5.0, p = 0.03, 95%, CI 1.9% to 25.6%). A majority of radiation oncologists (79%) and hyperbaric medicine physicians (85%) believe it is important that a new randomized controlled trial (RCT) is conducted (chi2 = 1.3, p = NS). CONCLUSIONS: While HBO2 has been used for decades, recent tissue-sparing radiation techniques and advanced surgical techniques are now calling into question the continued use of HBO2 for ORN prevention. Our results demonstrate that there is overwhelming support among responding practitioners for a new RCT.