Study Has Important Implications for Patient Monitoring after Head Trauma
Philadelphia, Pa. (November 8, 2011) – Low oxygen supply (hypoxia) to vulnerable brain tissue is a major contributor to the risk of death or major disability after severe traumatic brain injury (TBI), reports a study in the November issue of Neurosurgery, official journal of the Congress of Neurological Surgeons. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.
Led by Dr. Mauro Oddo of University of Pennsylvania Medical Center, Philadelphia, the researchers write, “Brain hypoxia is associated with poor short-term outcome after severe TBI”—independent of other factors like intracranial pressure and cerebral perfusion pressure (i.e. brain blood flow). The results support a recent guideline revision calling for monitoring of brain oxygenation during intensive care for patients with severe head injury.
Brain Hypoxia Linked to Increased Risk of Death or Severe Disability
Dr. Oddo and colleagues looked at how brain hypoxia affected clinical outcomes in 103 patients with TBI. Most of the patients had bleeding within the brain after severe, blunt head trauma. In addition to sensors placed for routine monitoring of intracranial (within the skull) pressure and brain blood flow, all patients underwent monitoring of brain oxygenation.
If the oxygen supply fell below a certain critical level, the patient was considered to have brain hypoxia. The relationship between brain hypoxia and the outcomes of TBI was assessed. Forty-three percent of patients had poor outcomes: death or survival with severe disability or in a vegetative state.
The greater the drop in brain oxygenation, the higher the risk of poor outcomes. The average length of time with brain hypoxia was 8.3 hours for patients with poor outcomes after TBI, compared to 1.7 hours for those with good outcomes—survival with no or moderate disability.
High intracranial pressure is traditionally regarded as a bad prognostic sign for patients with TBI. Among the patients in the study with high intracranial pressure, only 46 percent of those with brain hypoxia had good outcomes, compared to 81 percent of those without brain hypoxia.
Brain oxygenation was also a stronger outcome predictor than cerebral perfusion pressure. Some patients had good brain oxygenation, despite reduced brain blood flow, while maintaining presently recommended levels of cerebral perfusion pressure was sometimes insufficient to avoid low brain oxygenation.
After adjustment for these and other important risk factors, brain oxygenation was a significant and independent predictor of patient outcomes. For each additional hour with brain hypoxia, the risk of poor outcomes increased by 11 percent.
Delayed brain damage occurring in the hours and days after TBI is a major contributor to death and disability. Recently revised guidelines have recommended that patients with severe TBI should undergo monitoring of brain oxygenation—technically called interstitial partial pressure of oxygen in brain tissue. However, it has been unclear whether this provides important additional information, beyond that supplied by monitoring intracranial pressure or brain blood flow—or whether hypoxia is just an indicator of more severe brain injury.
The new study strongly suggests that TBI patients with longer periods of brain hypoxia are more likely to have poor outcomes, independent of intracranial pressure, brain blood flow, and other risk factors. The findings support the recent recommendations adding brain oxygen monitoring after severe TBI, as part of an integrated monitoring strategy. However, more research will be needed to determine whether treatment adjustments in response to brain oxygenation monitoring lead to any improvement in patient outcomes.
About Neurosurgery
Neurosurgery, the Official Journal of the Congress of Neurological Surgeons, is your most complete window to the contemporary field of neurosurgery. Members of the Congress and non-member subscribers receive 3,000 pages per year packed with the very latest science, technology, and medicine, not to mention full-text online access to the world’s most complete, up-to-the-minute neurosurgery resource. For professionals aware of the rapid pace of developments in the field, Neurosurgery is nothing short of indispensable.
About Lippincott Williams & Wilkins
Lippincott Williams & Wilkins (LWW) is a leading international publisher for healthcare professionals and students with nearly 300 periodicals and 1,500 books in more than 100 disciplines publishing under the LWW brand, as well as content-based sites and online corporate and customer services.
LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2010 annual revenues of €3.6 billion ($4.7 billion).
Complications after Breast Surgery Are More Common in Obese Women
Risk is 12 Times Higher than in Nonobese Women, Study Reports
Philadelphia, Pa. (October 27, 2011) – Obese women are at substantially higher risk of complications following breast surgery, according to a study in the November issue of Plastic and Reconstructive Surgery®, the official medical journal of the American Society of Plastic Surgeons (ASPS).
“Obesity is associated with a nearly twelve-fold increased odds of a postoperative complication after elective breast procedures,” concludes the report by Dr. Catherine Lee Chen and colleagues of The Johns Hopkins University School of Medicine, Baltimore. The results suggest that surgeon and hospital quality data should be adjusted to reflect the increased risks associated with surgery in obese patients.
Obesity Linked to Increased Complications of Breast Surgery
The researchers analyzed insurance claim data on approximately 8,000 women undergoing elective breast surgery between 2002 and 2006. Of the 8,000, 2,400 women (about 30 percent) were obese. For each type of procedure, rates and types of complications were compared for obese versus nonobese women.
Overall, about 18 percent of obese women filed an insurance claim covering a complication after breast surgery, compared to two percent of nonobese women. After adjustment for other factors, the risk of complications was 11.8 times higher for obese patients.
The difference was most pronounced for complications involving inflammation: more than 20 times greater than for nonobese women. Obese women were at higher risk of many other types of complications as well, including infection, pain and fluid collections (seroma or hematoma) after surgery.
Because the analysis was limited to procedures covered by health insurance, it did not include women undergoing aesthetic plastic surgery procedures, such as breast augmentation. More than 80 percent of the obese women in the study were undergoing breast reduction surgery, as did 64 percent of nonobese women. The next most common procedure was breast reconstruction, performed in 10 percent of obese women and 24 percent of nonobese women.
The obesity rate has risen rapidly in recent decades, to the point where 34 percent of U.S. adults are now estimated to be obese. “While the effect of obesity on disease has been established, its impact on short-term surgical outcomes has not been quantified,” Dr. Chen and colleagues write.
Important Implications for Measuring Surgical Quality
In addition to its impact on patient health, the study may have important economic implications—especially with the movement toward “pay for performance” plans linking financial reimbursement to standardized health care quality metrics. The standard metrics currently used for measuring health care quality don’t account for the possible increase in risk of complications in obese patients.
The new analysis provides evidence that obese women undergoing breast surgery are at greatly increased risk of complications. Even when other risk factors are taken into account, the complication rate is nearly 12 times higher for obese women. Researchers note that these excess complications could occur even though the doctor and hospital followed all recommended quality steps—for example, giving appropriate preventive antibiotics.
Dr. Chen and coauthors acknowledge some important limitations of their study—especially the fact that it was limited to patients undergoing procedures reimbursed by health insurance. They conclude, “As quality measures are increasingly applied to surgical evaluation and reimbursement, appropriate risk adjustment to account for the effect of obesity on outcomes will be essential.”
Plastic and Reconstructive Surgery® is published by Lippincott Williams & Wilkins, part of Wolters Kluwer Health.
About Plastic and Reconstructive Surgery
For more than 60 years, Plastic and Reconstructive Surgery® (http://journals.lww.com/plasreconsurg/) has been the one consistently excellent reference for every specialist who uses plastic surgery techniques or works in conjunction with a plastic surgeon. The official journal of the American Society of Plastic Surgeons, Plastic and Reconstructive Surgery® brings subscribers up-to-the-minute reports on the latest techniques and follow-up for all areas of plastic and reconstructive surgery, including breast reconstruction, experimental studies, maxillofacial reconstruction, hand and microsurgery, burn repair, and cosmetic surgery, as well as news on medico-legal issues.
About ASPS
The American Society of Plastic Surgeons (http://www.plasticsurgery.org/) is the largest organization of board-certified plastic surgeons in the world. Representing more than 7,000 physician members, the Society is recognized as a leading authority and information source on cosmetic and reconstructive plastic surgery. ASPS comprises more than 94 percent of all board-certified plastic surgeons in the United States. Founded in 1931, the Society represents physicians certified by The American Board of Plastic Surgery or The Royal College of Physicians and Surgeons of Canada.
About Lippincott Williams & Wilkins
Lippincott Williams & Wilkins (LWW) is a leading international publisher for healthcare professionals and students with nearly 300 periodicals and 1,500 books in more than 100 disciplines publishing under the LWW brand, as well as content-based sites and online corporate and customer services.
LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2010 annual revenues of €3.6 billion ($4.7 billion).
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