Objectives: Remote ischemic preconditioning (rIPC) is a novel technique in which brief episodes of ischemia and reperfusion in one organ confer protection against prolonged ischemia in a distant organ. In contrast, anesthetic-induced preconditioning (APC) utilizes volatile anesthetics to protect multiple organs from ischemia-reperfusion injury. Both methods are easily integrated into various clinical scenarios for cardioprotection. However, it remains unclear whether simultaneous application of these techniques could result in complementary, additive, synergistic, or adverse effects.

Methods: An adult rabbit heart Langendorff model of global ischemia/reperfusion injury was used to compare the cardioprotective effect of rIPC and APC alone and in combination relative to untreated (control) hearts. The rIPC group underwent four cycles of 5-minute ischemia on the hind limb, each followed by 5 minutes of reperfusion. The APC group received 2.5 vol% sevoflurane for 20 minutes via a face mask, followed by a 20-minute washout period.

Results: Both in vivo rIPC, induced by four 5-minute cycles of ischemia/reperfusion on the hind limb, and APC, administered as 2.5 vol% sevoflurane via a mask, significantly reduced the size of myocardial infarction following 30 minutes of global ischemia by >50% compared to the untreated control group (rIPC, 12.1±1.7%; APC, 13.5±2.1%; P<0.01 compared to control, 31.3±3.0%). However, no additional protective effect was observed when rIPC and APC were combined (rIPC+APC, 14.4±3.3%).

Conclusion: Although combining rIPC and APC did not provide additional protection, there was no inhibitory effect of one intervention on the other.

Objectives:

OxyMask, a novel product, has recently been used to administer oxygen postoperatively to patients who have undergone general anesthesia. This study aimed to evaluate the incidence of hypoxia in patients under general anesthesia upon arrival to the post-anesthesia care unit (PACU) using arterial blood gas analysis, and to compare the effectiveness of OxyMask with a non-rebreathing oxygen mask for oxygen administration.

Methods:

We retrospectively investigated anesthesia-related data from the electronic medical records of 460 patients treated from April to November 2021. We analyzed patients aged 20 years or older who had undergone general anesthesia and whose perioperative arterial blood gas analysis results were available upon arrival to the PACU. These patients were grouped into the non-rebreathing oxygen mask (n=223) and OxyMask (n=237) groups, and statistical analysis was performed utilizing their anesthesia records.

Results:

No patients exhibited hypoxia upon arrival to the recovery room. The oxygen concentration increased after oxygen administration; its concentration during the recovery room period (Δ2 PaO₂) was 10.7±42.3 and 13.9±38.5 mmHg in the non-rebreathing oxygen mask and OxyMask groups, respectively. This difference was not statistically significant. Moreover, the arterial oxygen saturation between the end of surgery and upon arrival to the PACU (Δ1 SaO₂) and the arterial oxygen saturation 20 minutes after oxygen administration at the PACU (Δ2 SaO₂) did not significantly differ between the groups.

Conclusion:

OxyMask was not superior to a non-rebreathing oxygen mask in terms of the effectiveness of oxygen supply.

ABSTRACT

Variant angina, which is associated with coronary artery spam, is difficult to recognize on routine preoperative evaluation. Coronary spasm results in myocardial ischemia and even lethal arrhythmia in severe cases. Since patients are unconscious and cannot complain of symptoms during general anesthesia, early detection of such an event is difficult, and it could lead to severe bradycardia or cardiac arrest. We report a case of a patient with previously undiagnosed variant angina who experienced severe hypotension and ventricular fibrillation during general anesthesia.

Citations

• Antihypotensive
  
  Reactions Weekly.2023; 1952(1): 65.     CrossRef