A systematic review of the literature on the use of regional anesthesia (RA) and patient-controlled analgesia (PCA) was conducted in patients who require orthopedic extremity procedures to determine whether either analgesic technique contributes to a delayed diagnosis of compartment syndrome (CS). A total of 34 relevant articles (28 case reports and six research articles) were identified. Of all case report articles published after 2009, the majority (75%) concluded that RA does not put the patient at an increased risk of a delayed diagnosis of CS. Of these, only two relevant prospective research studies focusing on RA or PCA and their relationship to CS were identified. Neither study resulted in any cases of CS. However, both had relatively small sample sizes. Given the lack of evidence identified in this systematic review, prospective studies or large-scale retrospective data reviews are needed to more strongly advocate the use of one modality of analgesia over the other in this patient population.

Inhalations of atmospheric pollutants, especially particulate matters, are known to cause severe cardiac effects and to exacerbate preexisting heart disease. Heart failure is an important sequellae of gaseous inhalation such as that of carbon monoxide. Similarly, other gases such as sulphur dioxide are known to cause detrimental cardiovascular events. However, mechanisms of these cardiac toxicities are so far unknown. Increased susceptibility of the heart to oxidative stress may play a role. Low levels of antioxidants in the heart as compared to other organs and high levels of reactive oxygen species produced due to the high energetic demand and metabolic rate in cardiac muscle are important in rendering this susceptibility. Acute inhalation of high concentrations of halogen gases is often fatal. Severe respiratory injury and distress occurs upon inhalation of halogens gases, such as chlorine and bromine; however, studies on their cardiac effects are scant. We have demonstrated that inhalation of high concentrations of halogen gases cause significant cardiac injury, dysfunction, and failure that can be critical in causing mortalities following exposures. Our studies also demonstrated that cardiac dysfunction occurs as a result of a direct insult independent of coexisting hypoxia, since it is not fully reversed by oxygen supplementation. Therefore, studies on offsite organ effects of inhaled toxic gases can impact development of treatment strategies upon accidental or deliberate exposures to these agents. Here we summarize the knowledge of cardiovascular effects of common inhaled toxic gases with the intent to highlight the importance of consideration of cardiac symptoms while treating the victims.