The safe treatment, monitoring and management of severe traumatic brain injury patients in a monoplace chamber.

This report describes how 27 patients with severe traumatic brain injury were safely treated, monitored and managed in a monoplace chamber that was compressed with air to 1.5 atmospheres absolute (152 kPa). A total of 75 hyperbaric oxygen treatments were delivered using the monoplace system described, with all patients receiving 100% oxygen via mechanical ventilation. Specific pieces of equipment, components and features were selected, and modifications were interfaced to safely and effectively treat these critically ill patients in a monoplace chamber. Patient monitoring included cardiovascular and ventilatory parameters as well as intracranial pressure, brain tissue oxygen levels, brain temperature and cerebral microdialysis. The chamber and all the supporting equipment for ventilating, monitoring and managing the patient functioned well.

Hyperbaric oxygen therapy of iatrogenic cerebral arterial gas embolism.

We describe our experience using HBO2 therapy for iatrogenic cerebral arterial gas embolism (CAGE) in this retrospective review of nineteen patients treated for iatrogenic CAGE, from 1987 to 1999. Immediately after treatment, five patients completely resolved all signs and symptoms, eleven had improvement, one had no change, and two were not assessable. Within two months post treatment, three additional patients completely resolved and six had further improvement. Patients with a venous source all experienced pulmonary signs or symptoms, with eight of nine chest x-rays demonstrating pulmonary edema. Patients with an arterial source had no pulmonary symptoms; all chest x-rays were clear. Imaging studies prior to HBO2 therapy demonstrated gas in six of 23 exams; five of the remaining 17 exams showed secondary changes consistent with gas embolism. Iatrogenic CAGE patients improved with HBO2 therapy, and improvement for some continued for several months. Patients with CAGE from a venous source have pulmonary signs or symptoms. Diagnosis of CAGE should be made on clinical suspicion without reliance on imaging studies.

Adjunctive hyperbaric oxygen in irradiated patients requiring dental extractions: outcomes and complications.

PURPOSE: This study assessed complications of hyperbaric oxygen (HBO) therapy, potential predictors of poor outcome, and treatment outcomes in irradiated patients undergoing dental extractions. PATIENTS AND METHODS: This was a prospective, descriptive study of 40 consecutive patients treated with HBO before and after dental extractions in an irradiated field. All patients had radiation caries; none had osteoradionecrosis (ORN). All were prescribed a protocol of 20 pre-extraction and 10 postextraction HBO treatments at 2.4 ATA for 90 minutes. Potential risk factors for poor healing and risk factors for complications were identified. All complications were recorded. Extraction site healing was evaluated at the conclusion of HBO therapy, at 1 month, and 1 year later. RESULTS: There were no serious complications. There was no correlation between preidentified risk factors and poor healing. At 1 year, 98.5% of all extraction sites were healed. Patients who did not heal were an average of 8 years since radiation, compared with 3.3 years for those who healed (P <.001). CONCLUSION: Use of HBO is associated with a very low incidence of ORN at 1-year follow-up. However, the time since radiation has a positive correlation with risk for ORN.

Ocular quinine toxicity treated with hyperbaric oxygen.

Ocular quinine toxicity typically involves a partial or total and often permanent loss of vision. Apart from gastric lavage and oral administration of activated charcoal, current treatment modalities are of doubtful efficacy. Two patients with quinine amaurosis were treated with hyperbaric oxygen (HBO2) in an effort to increase oxygen delivery to the retina. Visual outcomes in these patients were evaluated. Two patients had bilateral no light perception vision and dilated, nonreactive pupils within hours of ingesting 13-15 g of quinine in addition to other drugs. Following initial oral charcoal administration, HBO2 therapy was used. Within 17 h after quinine ingestion, both patients underwent HBO2 therapy at 2.4 atm abs with 100% O2 for 90 min. Both patients had return of visual acuity to 20/20 in both eyes less than 24 h after treatment. Follow-up visual fields revealed constriction and paracentral scotomas bilaterally. We conclude that HBO2 may represent an additional or alternative, and perhaps safer, method of treatment for ocular quinine toxicity.

Hyperbaric treatment of cerebral air embolism sustained during an open-heart surgical procedure.

A case of cerebral air embolism sustained during replacement of the mitral valve resulted in postoperative coma and seizures. Hyperbaric treatment, begun 30 hours after the occurrence of the air embolism, resulted in good immediate and long-term recovery. Mild deficits of the left hemisphere were present at follow-up 53 days after the embolus was sustained, and lesser, minimal residua were present at 14-month follow-up. Hyperbaric treatment is the definitive therapy for cerebral air embolism. Although it is most effective when administered early, the outcome may be excellent even with late treatment.

Middle components of the auditory evoked potentials in infants.

Middle components of the averaged auditory evoked potentials (AEP) were recorded from 18 infants, 6 each at one, four and eight months of age, during natural sleep, Tone bursts centered at 1000 Hz were presented from a loudspeaker at 15, 30, 45 and 60 dB HL (re: normal adult tone burst threshold). In addition, an equal duration no stimulus control AEP was also obtained. Each averaged response consisted of the sum of 400 stimuli presented at a rate of about 6/sec. Latencies and amplitudes of the three peaks, Na, Pa and Nb, were analyzed as a function of age and intensity. There were no significant differences in latency as a function of age, and only peak Pa showed a significant increase in amplitude as a function of increasing age. The latency of peak Pa decreased significantly as a function of intensity, while the amplitude of all three peaks showed significant differences as a function of intensity. Judges' scores of the presence of responses showed that at 60 dB HL, all infants yielded patterns which were scored as "response present." Smaller percentages of "response present" were scored for the successively lower intensity levels. The results from the 18 infants in this study were similar to those obtained from six normal, sleeping adults tested under identical stimulating and recording conditions in this laboratory.