Orthopedic surgery pain control; ginger for postoperative nausea and vomiting; transfusion risks; anesthesia for knee arthroscopy

AORN Journal,  May, 2006  by George Allen

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Efficacy of opioid treatment for pain after orthopedic surgery Archives of Physical Medicine and Rehabilitation December 2005

Acute postoperative pain is believed to be undertreated. In addition to causing needless suffering, untreated pain may decrease patients' productivity and increase health care costs. The clinical usefulness of opioids for the treatment of pain has long been recognized, and morphine and its derivatives have been used widely.

There are ongoing concerns regarding opioids, however, including side effects and the need for frequent dosing, that highlight the need for new agents with proven efficacy, tolerability, and improved pharmacokinetic and pharmacodynamic profiles. Oxymorphone, a semisynthetic opioid first approved by the US Food and Drug Administration in 1959, possesses a significantly greater analgesic potency than its parent compound (ie, morphine). Although the efficacy of a new formulation (ie, oxymorphone immediate release [IR] 10 mg, 20 mg, 30 mg) has been established in patients with moderate to severe acute pain after orthopedic surgery involving osteotomy, the efficacy of 5 mg oxymorphone IR has not been studied. Oxymorphone IR at 5 mg may be useful in a variety of clinical settings, including for use as rescue medication for breakthrough pain or when initiating therapy with patients who have had little or no previous exposure to opioids. The purpose of this multicenter, double-blind, randomized, placebo-controlled study was to assess the analgesic efficacy and safety of 5 mg oxymorphone IR for mild to moderate pain. (1)

Participants eligible for the study were men and women 18 years of age or older who had undergone outpatient knee arthroscopy at one of eight ambulatory centers located in Utah, Arizona, and Alabama. Female participants could not be pregnant or lactating. In addition, eligible participants had an initial pain intensity score between 30 mm and 70 mm on a 100-mm visual analog scale and a pain rating of mild or moderate on a categorical scale with possible ratings of none, mild, moderate, or severe.

Participants were randomly assigned to receive either 5 mg oxymorphone IR or placebo for up to eight hours. After administration of the first dose of study medication, participants were discharged with a diary; study medication (ie, 5 mg oxymorphone IR or placebo); and a rescue analgesic, with instructions to take the study medication as needed, but not more frequently than once every hour for up to eight hours. Participants recorded the date and time of each dose of study medication in the diaries. Participants who used the rescue medications were eliminated from the study.

Participants were contacted by study personnel on the evening of surgery and the morning after surgery for an assessment of study medication use and adverse events. In addition, participants were asked to provide a global assessment of pain relief on the morning after surgery, and all participants returned to the study site within seven days after surgery for an end-of-study assessment. The primary endpoint was the sum of the pain intensity scores from baseline to eight hours. Pain intensity scores were calculated at baseline (ie, the time of the initial dose); 30 minutes postdose; and one, two, three, four, five, six, seven, and eight hours postdose. Common statistical procedures, including analysis of covariance, were used to analyze the data.

Findings. Of the 122 participants who were enrolled in the study, 60 received 5 mg oxymorphone IR (ie, the treatment group) and 62 received placebo (ie, the control group). Oxymorphone IR at 5 mg was significantly better than placebo for the primary efficacy endpoint (P < .05). The mean sum of the pain intensity scores at baseline to eight hours showed greater pain relief in the treatment group compared to the placebo group (least square mean difference [+ or -] standard error 76.9 [+ or -] 28.09, 05% confidence interval [CI] 21.26-132.59, P = .007). More participants in the placebo group (ie, 48.4%) required rescue medications than in the treatment group (ie, 16.7%). Additionally, more participants (ie, 47.4%) rated 5 mg oxymorphone IR "very good" or "excellent" for pain relief versus placebo (ie, 25%).

Clinical implications. The results of this study revealed that 5 mg oxymorphone IR was well tolerated and effective in relieving mild or moderate pain after outpatient knee surgery. Perioperative nurses should realize that additional studies are warranted to determine if a lower dose of oxymorphone IR is an appropriate treatment option for orthopedic outpatients.

Ginger use for preventing postoperative nausea and vomiting American Journal of Obstetrics and Gynecology January 2006

Postoperative nausea and vomiting (PONV) is a common but distressing outcome associated with surgical procedures, and it can lead to medical complications such as wound disruption; esophageal tears; gastric herniation; fatigue; dehydration; and possibly, electrolyte imbalances. Additionally, because PONV may increase hospital length of stay, it is associated with increased cost. Despite numerous studies investigating the efficacy of various antiemetics, no intervention has yet emerged as universally effective or has been accepted as the gold standard.