Background Mild perioperative hypothermia, which is common during major surgery, may promote surgical-wound infection by triggering thermoregulatory vasoconstriction, which decreases subcutaneous oxygen tension. Reduced levels of oxygen in tissue impair oxidative killing by neutrophils and decrease the strength of the healing wound by reducing the deposition of collagen. Hypothermia also directly impairs immune function. We tested the hypothesis that hypothermia both increases susceptibility to surgical-wound infection and lengthens hospitalization. Methods Two hundred patients undergoing colorectal surgery were randomly assigned to routine intraoperative thermal care (the hypothermia group) or additional warming (the normothermia group). The patients' anesthetic care was standardized, and they were all given cefamandole and metronidazole. In a double-blind protocol, their wounds were evaluated daily until discharge from the hospital and in the clinic after two weeks; wounds containing culture-positive pu...

https://www.nejm.org/doi/pdf/10.1056/NEJM199605093341901

Perioperative Normothermia to Reduce the Incidence of Surgical-Wound Infection and Shorten Hospitalization

Hyperbaric oxygen — 100 percent oxygen at two to three times the atmospheric pressure at sea level — can result in arterial oxygen tension in excess of 2000 mm Hg1 and oxygen tension in tissue of almost 400 mm Hg.2,3 Such doses of oxygen have a number of beneficial biochemical, cellular, and physiologic effects, and today there are 259 hyperbaric facilities in the United States with 344 single-occupant (“monoplace”) hyperbaric-oxygen chambers.4 In this article, we review the mechanisms of action, evidence of clinical efficacy, and risks of therapy with hyperbaric oxygen. Physiologic Effects For hyperbaric oxygen, pressure is expressed . . .

Hyperbaric-Oxygen Therapy

On the Nature of Hypertrophic Scars and Keloids: A Review Frank Niessen;Paul Spauwen;Joost Schalkwijk;Moshe Kon; Plastic and Reconstructive Surgery

On the nature of hypertrophic scars and keloids : A review

INTRODUCTIONJon Terry Mader (Fig 1) was born on March 21, 1944 in Madison, WI. He earned his BA and MD degrees at Wabash College at Indiana University in 1966 and 1970, respectively. He trained in Internal Medicine at the University of Texas Medical Branch in Galveston, TX and made his career there

http://hyperbaricinformation.com/HBO-Articles/HBO-Infection/Clin-Orthopaedics-Related-Res-2003-1(414)-Mader-Staging-oste.pdf

A clinical staging system for adult osteomyelitis.

Objective: To test the hypothesis that subcutaneous wound oxygen tension (PsqO2) has a predictive relation to the development of wound infection in surgical patients. Design: A noninterventional, prospective study. Setting: A university department of surgery. Patients: One hundred thirty operative general surgical patients at notable risk of infection as predicted by an anticipated Study on the Effect of Nosocomial Infection Control (SENIC) score of 1 or greater. Outcome Measures: PsqO2was measured perioperatively. Its relation to the subsequent incidence of surgical wound infection was then determined and compared with the SENIC score as a criterion standard. Results: Although the SENIC score and PsqO2are inversely correlated, PsqO2 is the stronger predictor of infection. Low PsqO2identified patients at risk and concentrated them in a cohort that was about half the size of that identified by the SENIC score. Conclusions: Subcutaneous perfusion and oxygenation are important components of immunity to wound infections. The SENIC score identifies systemic physiological variables that are important to the development of wound infection. Nevertheless, PsqO2More-he more powerful predictor of wound infection. Moreover, PPsqOcan be manipulated by available clinical means, and thus may direct interventions to prevent infection. Arch Surg. 1997;132:997-1004

https://jamanetwork.com/HttpHandlers/ArticlePdfHandler.ashx?journal=SURG&articleId=596942&pdfFileName=archsurg_132_9_010.pdf

Wound Tissue Oxygen Tension Predicts the Risk of Wound Infection in Surgical Patients

Although hyperbaric oxygen (HBO) is as effective as cephalothin against osteomyelitis due to Staphylococcus aureus in the rabbit, the effect is not by directing killing. To investigate the mechanism, argon washouts (perfusion) and oxygen tensions were measured by intramedullary probes placed in the metaphyses of infected and uninfected tibias. In vitro phagocytic killing activity for S. aureus was determined at oxygen tensions found in these bones under ambient and HBO conditions. Mean tibial oxygen tensions (mm Hg) under ambient conditions were 21 (infected) and 45 (uninfected); under HBO conditions, 104 (infected) and 321 (uninfected). Perfusion was decreased in osteomyelitic bone and was not acutely increased by HBO in either normal or infected bone. Phagocytic killing of S. aureus was markedly decreased at 23 mm Hg of O2, significantly improved at 45 and 109 mm Hg, and most effective at 150 mm Hg. Thus, in osteomyelitic bone, HBO increased intramedullary oxygen to tensions consistent with normal phagocytic function.

A Mechanism for the Amelioration by Hyperbaric Oxygen of Experimental Staphylococcal Osteomyelitis in Rabbits

The partial pressures of oxygen and carbon dioxide have been measured in hypertrophic scars in burned patients, using mass spectroscopy. The pO2 in scar tissue was significantly depressed in comparison to the pO2 in normal dermis (a decrease of 13.1 +/- 2.9 mm Hg). The pCO2 was noted to be increased in the scar tissue (2.6 +/- 1.6 mm Hg). The possible significance of these findings is discussed.

Tissue gases in human hypertrophic burn scars.

Effects of nicotinic acid upon post-burn oedema: a preliminary report of clinical trials

The effects of single and multiple doses of indomethacin and multiple doses of nicotinic acid upon Escherichia coli endotoxin shock were studied in mongrel dogs anesthetized with sodium pentobarbital. Survival, cardiac output, plasma volume loss, and mean arterial pressure were measured. Untreated animals did not survive the procedure; animals treated with either multiple doses of indomethacin or nicotinic acid did survive for 5 hours after endotoxin. Plasma volume losses of indomethacin and nicotinic acid treated animals were substantially less (p less than 0.05) than in untreated animals. Arterialpressures of indomethacin-treated animals were greater than that of either nicotinic acid treated or untreated animals. No differences in cardiac output were noted in surviving animals.

Effects of indomethacin and nicotinic acid on E. coli endotoxin shock in anesthetized dogs.

Intravenous administration of nicotinic acid to the anesthetized dog prior to thermal trauma reduced plasma loss at 10 minutes after burn from 7 milliliters per kilogram to less than 2 millimeters per kilogram. During the next 50 minutes plasma loss was the same in treated and untreated animals. An additional dose of nicotinic acid 30 minutes after burn prevented this further loss.

Charles H. Wells

Papers

A Mechanism for the Amelioration by Hyperbaric Oxygen of Experimental Staphylococcal Osteomyelitis in Rabbits

Tissue gases in human hypertrophic burn scars.

Effects of nicotinic acid upon post-burn oedema: a preliminary report of clinical trials

Effects of indomethacin and nicotinic acid on E. coli endotoxin shock in anesthetized dogs.

Nicotinic acid reduction of plasma volume loss after thermal trauma