Decompression illness, iatrogenic gas embolism, and carbon monoxide poisoning: the role of hyperbaric oxygen therapy

Assessment of the hyperbaric oxygen therapy effects in distal femoral necrosis using hyperspectral imaging

Introduction. Hyperbaric oxygen therapy is a treatment option for an increasing number of conditions. The aim of this study was to assess its therapeutic effects in femoral condylar necrosis as well as in normal tissue using hyperspectral imaging. Material and method. A 47-year-old female patient diagnosed with avascular necrosis of the medial femoral condyle was included in this study. The patient received hyperbaric oxygen therapy for two consecutive days (the first day: three stages of 30 min each, separated by two breaks of 5 min at pO2 = 2 ATA; the second day: three stages of 30 min each, separated by two breaks of 5 min at pO2 = 2.4 ATA). The effects of hyperbaric oxygen therapy on the affected area (patient’s knee) and normal (patient’s hand) tissues oxygenation were assessed before and after each treatment session using hyperspectral imaging. Results and discussions. The results showed that hyperspectral imaging is quite good for monitoring the hyperbaric oxygen therapy efficacy in affected areas, even with deep tissue problems. Conclusions. In conclusion, the hyperspectral imaging-based approach for monitoring hyperbaric oxygen therapy could support physicians in extracting prognostic information and making the right treatment decisions. Keywords: bone necrosis, image analysis, maps, oxyhemoglobin, deoxyhemoglobin, oxygen saturation,

Paradoxical carbon dioxide embolism during laparoscopic surgery without intracardiac right-to-left shunt: two case reports and a brief review of the literature

We herein report two cases of paradoxical carbon dioxide (CO₂) embolism during laparoscopic nephrectomy and hepatic left lateral lobectomy without evidence of a right-to-left shunt or obvious rupture of blood vessels. Transesophageal echocardiography detected paradoxical CO₂ embolism before the end-tidal CO₂ partial pressure (P_ETCO₂) dropped from baseline. The pneumoperitoneum was reduced or stopped immediately after detection of the embolism. One patient developed a postoperative epileptiform seizure. In the other patient, many gas bubbles were drawn out from the central venous line. We speculate that rapid introduction of pneumoperitoneum pushed a large amount of CO₂ into the abdominal blood vessels, exceeding the gas exchange capacity of the lung and causing CO₂ bubble formation in the left-side cardiac system. These two cases indicate that intraoperative transesophageal echocardiography can reduce the influence of CO₂ embolism during laparoscopic tumor surgery by early diagnosis of the embolism and provide helpful information to establish a list of differential diagnoses of postoperative complications.

Iatrogenic systemic air embolism treated with hyperbaric oxygen therapy

Air embolism is a rare and potentially severe complication of surgical and invasive procedures. Emboli large enough to produce symptoms require immediate treatment because of the risk of 'gas lock' in the right side of the heart and subsequent circulatory failure. If air is transmitted to the arterial circulation through a shunt, it may cause cerebral emboli with neurological symptoms. We present two cases with venous air emboli and concurrent cerebral arterial emboli. Both patients were successfully treated with hyperbaric oxygen therapy.

Cerebral air embolization in the Electrophysiology Laboratory during Transseptal Catheterization: Curative treatment of acute left hemiparesis with prompt hyperbaric oxygen therapy

We present a case of a 44 year-old man with medically refractory symptomatic paroxysmal atrial fibrillation in whom the initial attempt at left atrial catheter ablation was complicated by coronary and cerebral arterial air embolization during transseptal catheter exchange. The manifestations, management, and long term outcomes are detailed. Following the case report is a review of published reports and contemporary management strategies for treatment of acute air embolization. Dramatic clinical consequences can be aborted by prompt intervention including volume loading, oxygenation, lidocaine, and hyperbaric oxygen therapy.

[Diving accidents. Emergency treatment of serious diving accidents]

Decompression injuries are potentially life-threatening incidents mainly due to a rapid decline in ambient pressure. Decompression illness (DCI) results from the presence of gas bubbles in the blood and tissue. DCI may be classified as decompression sickness (DCS) generated from the liberation of gas bubbles following an oversaturation of tissues with inert gas and arterial gas embolism (AGE) mainly due to pulmonary barotrauma. People working under hyperbaric pressure, e.g. in a caisson for general construction under water, and scuba divers are exposed to certain risks. Diving accidents can be fatal and are often characterized by organ dysfunction, especially neurological deficits. They have become comparatively rare among professional divers and workers. However, since recreational scuba diving is gaining more and more popularity there is an increasing likelihood of severe diving accidents. Thus, emergency staff working close to areas with a high scuba diving activity, e.g. lakes or rivers, may be called more frequently to a scuba diving accident. The correct and professional emergency treatment on site, especially the immediate and continuous administration of normobaric oxygen, is decisive for the outcome of the accident victim. The definitive treatment includes rapid recompression with hyperbaric oxygen. The value of adjunctive medication, however, remains controversial.

Decompression illness in divers: a review of the literature

BACKGROUND

Neurologists may be consulted to diagnose and treat the severe neurologic injuries that can occur in divers with decompression illness (DCI).

REVIEW SUMMARY

Subclinical bubbles form during normal diving activity. DCI, a diffuse and multifocal process, results when bubbles cause symptoms by exerting mass effect in tissues, or obstructing venous or arterial flow. The lower thoracic spinal cord is a commonly affected area of the central nervous system. The most commonly described form of brain DCI is cerebral arterial gas embolism with middle cerebral artery or vertebrobasilar distribution involvement. Bubbles exert secondary damage to the vascular endothelium, causing activation of numerous biochemical cascades.

CONCLUSIONS

Divers can develop DCI on very short dives or in shallow water, even when adhering to protocols. DCI should be strongly considered when divers experience pain after diving. Any neurologic symptoms after a dive are abnormal and should be attributed to DCI. Even doubtful cases should be treated immediately with hyperbaric oxygen (HBO), after a chest x-ray to rule out pneumothorax. The Divers Alert Network should be contacted for emergency consultation. Delay to treatment can worsen outcome; however, the overwhelming majority of divers respond to HBO even days to weeks after injury. Although DCI is a clinical diagnosis, magnetic resonance imaging, somatosensory evoked potentials, single-photon emission tomography, and neuropsychologic testing help to document disease and monitor response to therapy. Divers should be treated with HBO until they reach a clinical plateau. Complete relief of symptoms occurs in 50% to 70% of divers; 30% have partial relief.