Article – 1 - Arterial Gas Embolism
Title: Cerebral venous air embolism treated with hyperbaric oxygen: a case report.
Authors: Bothma, PA; Brodbeck, AE; Smith, BA
Abstract: We present a case of cerebral venous gas embolism. Our patient made a complete neurological recovery after hyperbaric oxygen therapy (HBOT). The principles of HBOT, compressing and eliminating air bubbles and decreasing Β-2 integrin function, thus improving microcirculation, can only be beneficial in a situation where neurological damage is likely. Retrograde cerebral venous gas embolism is a less well recognised variant of gas embolism than the arterial variant. Its existence as a different entity is better recognised in the forensic medicine and radiology literature than in other disciplines. There is evidence in the literature of patients dying from this complication and others seemingly experiencing very little effect.
Conclusion: This case report highlights this condition, to encourage others to look out for it and report outcomes, and to serve as a reminder that peripheral lines may be a potential cause of gas embolism, although the portal of air entry in our case remains uncertain.
Article – 2 - Arterial Gas Embolism
Title: Cerebral arterial air embolism: I. Is there benefit in beginning HBO treatment at 6 bar?
Authors: Leitch, DR; Greenbaum Jr, LJ; Hallenbeck, JM
Digital Object Identifier (or PMID etc): PMID: 6506335
Keywords: Animals Cerebral Arterial Diseases/etiology/physiopathology/*therapy Comparative Study Disease Models, Animal Diving/adverse effects Dogs Embolism, Air/etiology/physiopathology/*therapy Evoked Potentials, Somatosensory Human *Hyperbaric Oxygenation Male Submarine Medicine
Abstract: A method for studying treatment of cerebral arterial gas embolism in dogs is described. The model produces severe cortical dysfunction and cerebral blood flow deficits. The efficacy of treatment was assessed using median nerve somatosensory cortical evoked potentials (CEP), [14C]iodoantipyrene autoradiographic cerebral blood flow studies, brain water content, and various physiological parameters. A direct comparison of modified U.S. Navy Treatment Tables 6 and 6A is reported. Complete recovery of CEP was not seen after 90 min of treatment. The maximum rate of CEP recovery occurred in the first 15 min of treatment. Recovery continued out to 60 min. Thereafter, some dogs on treatment 6A showed signs of deterioration. The cerebral blood flow studies were the same in both groups and showed no sign of pathologically low levels of flow.
Conclusion: It appeared that there was no advantage in preceding 2.8-bar (60-ft) oxygen treatments with compression to 6 bar (165 ft) on air for the treatment of arterial air embolism in this model.
Article – 3 - Arterial Gas Embolism
Title: Cerebral arterial air embolism: II. Effect of pressure and time on cortical evoked potential recovery
Authors: Leitch, DR; Greenbaum Jr, LJ; Hallenbeck, JM
Digital Object Identifier (or PMID etc): PMID: 6506336
Keywords: Animals Atmospheric Pressure Cerebral Arterial Diseases/physiopathology/*therapy Comparative Study Dogs Embolism, Air/physiopathology/*therapy Evoked Potentials, Somatosensory Human *Hyperbaric Oxygenation Male
Abstract: In a dog model of cerebral arterial gas embolism we studied the relative merits of several different treatments: air breathing at 2.8, 6, 8, and 10 bar (60, 165, 230, and 300 ft), and oxygen breathing at 2.8 bar. The study was confined to the recovery of cortical evoked potentials (CEP) while at pressure. It was confirmed that this was a very severe model; few dogs achieved full recovery and three failed to show any recovery. Injecting 0.4 ml of air into the right internal carotid artery was seen to be as effective in suppressing function in the left hemisphere as in the right. The level of recovery with compression treatment as a percentage of control was directly related to the level to which CEP was suppressed. No other physiological correlates were found with either the degree of CEP suppression or the degree of recovery.
Conclusion: Nor was any improvement observed in the rate or maximum amount of recovery at any time out to 20 min as a result of pressures greater than 2.8 bar. Overall, no treatment surpassed oxygen at 2.8 bar.
Article – 4 - Arterial Gas Embolism
Title: Hyperbaric oxygen therapy of iatrogenic cerebral arterial gas embolism.
Authors: Benson, J; Adkinson, CD; Collier, RE
Abstract: 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.
Conclusion: 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.
Article – 5- Arterial Gas Embolism
Title: Arterial air embolism after a percutaneous needle lung aspiration.
Authors: Peters, EJ; Boyars, MC
Abstract: A 31-yr-old male with acquired immunodeficiency syndrome suffered multiple arterial air emboli after a single percutaneous thin-needle lung aspiration. The diagnosis was established on the basis of the clinical presentation and response to therapy.
Conclusion: A complete neurologic recovery was achieved with the rapid initiation of hyperbaric oxygen therapy.
Article – 6 - Arterial Gas Embolism
Title: Cerebral arterial air embolism: IV. Failure to recover with treatment, and secondary deterioration
Authors: Leitch, DR; Greenbaum Jr, LJ; Hallenbeck, JM
Digital Object Identifier (or PMID etc): PMID: 6506338
Keywords: Animals, Cerebral Arterial Diseases/physiopathology/*therapy Cerebrovascular Circulation Comparative Study Decompression Diving/adverse effects Dogs Embolism, Air/physiopathology/*therapy Evoked Potentials, Somatosensory *Hyperbaric Oxygenation Intracranial Pressure Male
Abstract: Cerebral arterial gas embolism was induced in 23 dogs that were then treated using one of six routines: no treatment; air at 2.8 bar (60 ft) for 2 min; air at 10 bar (300 ft) for 5 min; oxygen at 2.8 bar for 10 or 20 min; and air at 6 bar (165 ft) for 10 min. After decompression they were monitored for a total of 90 min after the time of embolization. The dogs then underwent an autoradiographic study of cerebral blood flow (CBF). A number of the air-treated dogs experienced a reduction in cortical evoked potential after decompression. Dogs in all groups, except the untreated group and the dog at 10 bar for 5 min, showed an improved CBF compared with their short-study counterparts. After compression treatment, CBF improved with time. Function in 7 dogs deteriorated to a variable small degree in the air-treated groups, while only 3 dogs in the group on oxygen for 10 min deteriorated by around 10percent. The CBF of the oxygen groups was close to the undived control values, and their cerebrospinal fluid (CSF) pressures had returned to control levels.
Conclusion: There was dissociation between improving CBF and deteriorating function. It is evident that secondary deterioration is a random affair and therefore not easily studied. The results of the four-part series are summarized and discussed.
Article – 7 - Arterial Gas Embolism
Title: Arterial gas embolism in a diver using a closed-circuit oxygen rebreathing diving apparatus.
Authors: Carstairs, S
Digital Object Identifier (or PMID etc): PMID: 12153151
Keywords:
Abstract: A U.S. Marine Corps Reconnaissance diver suffered arterial gas embolism (AGE) while using a closed-circuit oxygen rebreathing scuba apparatus; there are few, if any, reported occurrences of AGE due to gases other than air.
Conclusion: The high oxygen fraction of the diver's inspired gas may have contributed to his rapid recovery once recompression therapy was initiated.
Article – 8 - Arterial Gas Embolism
Title: Pneumothorax as a complication of recompression therapy for cerebral arterial gas embolism
Authors: Broome, JR; Smith, DJ
Digital Object Identifier (or PMID etc): PMID: 1304671
Abstract: The danger from pneumothorax in patients who undergo compression chamber treatment for cerebral arterial gas embolism (CAGE) following pulmonary barotrauma is frequently emphasized. Two cases of CAGE treated by recompression after submarine escape tank training (SETT) accidents are described. Both were complicated by bilateral pneumothoraces but the first case, treated on an air table, required thoracentesis in the chamber, whereas the second case, treated on an oxygen table, escaped the need for in-chamber thoracentesis despite large pneumothoraces. Review of similar Royal Navy and United States Navy SETT accidents suggests that the danger from pneumothorax during recompression treatment of CAGE victims may be overstated. Modern management on oxygen-based therapeutic recompression tables may significantly reduce the risk.
Conclusion: Thoracentesis while under pressure should be reserved for cases developing symptoms or signs of tension pneumothorax. Treatment options for these cases are discussed and a decision algorithm is proposed.
Article – 9 - Arterial Gas Embolism
Title: Monoplace hyperbaric chamber use of U.S. Navy Table 6: a 20-year experience.
Authors: Weaver, LK
Abstract: We report a 20-year experience at LDS Hospital, Salt Lake City, UT using the U.S. Navy Treatment Table 6 (TT6) in an oxygen-filled monoplace hyperbaric chamber (1985-2004). Air breathing was provided via a demand regulator fitted with a SCUBA mouthpiece while the patient wore a nose clip. Intubated patients were mechanically ventilated with a Sechrist 500A ventilator, with a modified circuit providing air, when specified. We treated 90 patients: 72 divers (decompression sickness [DCS] = 67, arterial gas embolism [AGE] = 5), 10 hospital-associated AGE, and 8 miscellaneous conditions. They received a total of 118 TT6 (9 TT6 in intubated patients). Ninety-four percent of the TT6 schedules were tolerated and completed. The intolerance rate from two surveyed multiplace chambers was zero and 3% of 100 TT6 schedules each. Failure to complete the TT6 was due to oxygen toxicity (4) and claustrophobia (3).
Conclusion: The U.S. Navy TT6 was well tolerated by patients with DCS or AGE treated in monoplace hyperbaric chambers, but tolerance may not be as high as when treated in the multiplace chamber.
Article – 10 - Arterial Gas Embolism
Title: Case reports: hyperbaric oxygen therapy for the treatment of cerebral air embolism.
Authors: Brito, T; Pithan, N; Martins, G; Jessen, B; Assumpção, C; Porto, T; Filho, O; Siqueira-Filho, A
Abstract: Cerebral air embolism is one of the most deleterious disorders that may affect divers, but it is also a possible complication of surgeries and medical procedures.
Conclusion: We report our experience with iatrogenic cerebral air embolism and hyperbaric oxygen treatment.