The following is a summary of “Clinical and biochemical short-term effects of hyperbaric oxygen therapy on SARS-Cov-2+ hospitalized patients with hypoxemic respiratory failure,” published in the February 2023 issue of Pulmonology by Keller, et al.

Hyperbaric oxygen therapy (HBOT) has been suggested as a potential treatment for respiratory failure caused by COVID-19. However, the biological effects of HBOT needed to be better understood. To investigate the biochemical effects of HBOT in COVID-19 patients, a study was conducted with 50 patients who had hypoxemic COVID-19 pneumonia. The patients were divided into two groups: the C group, which received standard care, and the H group, which received standard care plus HBOT.

Blood samples were collected from the patients at two time points: at the start of the study and five days later. Oxygen saturation was monitored throughout the study. The blood samples were analyzed for various factors, including white blood cell (WC) count, lymphocytes (L), and platelets (P), and serum analysis of glucose, urea, creatinine, sodium, potassium, ferritin, D dimer, LDH, and CRP. Additionally, levels of plasma cytokines (IL-1β, IL-1RA, IL-6, TNFα, IFNα, IFNγ, IL-15, VEGF, MIP1α, IL-12p70, IL-2, and IP-10) and other molecules were measured using multiplex assays, including sVCAM, sICAM, sPselectin, SAA, MPO, and Angiotensin Converting Enzyme 2 (ACE-2) levels were determined by ELISA.

The average basal oxygen saturation (O2 Sat) was 85 ± 3%, and it took the HBOT group 3 ± 1 days to reach an O2 Sat >90%, while the control group took 5 ± 1 days (P < 0.01). At the end of the study, the HBOT group showed increased white blood cell (WBC), lymphocyte (L), and platelet (P) counts compared to the control group (all, HBOT vs control: P < 0.01). 

Additionally, the HBOT group had reduced D-dimer levels (HBOT vs control, P < 0.001) and lactate dehydrogenase (LDH) concentration (HBOT vs control, P < 0.01). The HBOT group also had lower levels of sVCAM, sPselectin, and SAA than the control group (HBOT vs control: ΔsVCAM: P < 0.01; ΔsPselectin: P < 0.05; ΔSAA: P < 0.01). Furthermore, the HBOT group showed decreased levels of TNFα (ΔTNFα: P < 0.05) and increased levels of IL-1RA and VEGF compared to the control group (HBOT vs control: ΔIL-1RA and ΔVEGF: P < 0.05).

In conclusion, the study suggested that HBOT may be an effective treatment for hypoxemic COVID-19 pneumonia, as it improves oxygen saturation levels and reduces disease severity markers (WC and platelets count, D dimer, LDH, SAA) and pro-inflammatory molecules (sVCAM, sPselectin, TNFα) while increasing anti-inflammatory and pro-angiogenic molecules (IL-1RA and VEGF). However, further studies are needed to confirm these findings and determine the optimal use of HBOT in COVID-19 treatment.

Reference: resmedjournal.com/article/S0954-6111(23)00043-4/fulltext