Analgesic efficacy of controlled-release oxycodone in postoperative pain

The efficacy and safety of graded doses (10, 20, and 30 mg) of controlled-release (CR) oxycodone was compared with that of immediate-release (IR) oxycodone (15 mg), immediate-release oxycodone 10 mg in combination with acetaminophen 650 mg (APAP), and placebo in a single-dose, double-blind, randomized, parallel-group study. The participants, 182 inpatients experiencing moderate to severe pain after abdominal or gynecologic surgery, provided hourly ratings of pain intensity and relief for 12 hours after administration. All active treatments were significantly superior to placebo for many hourly measurements and for the sum of pain intensity differences (SPID) and total pain relief (TOTPAR). A dose response was found among the three levels of CR oxycodone for pain relief and peak pain intensity difference (PID), with the 20- and 30-mg doses being significantly better than the 10-mg dose. For all active treatments, peak PID and peak pain relief occurred approximately 2 to 4 hours after administration. The median time to onset of relief was 32 minutes for oxycodone plus APAP, 41 minutes for IR oxycodone, and 46 minutes for CR oxycodone 30 mg. Duration of pain relief showed that the 10-, 20-, and 30-mg doses of CR oxycodone had durations of action of 10 to 12 hours compared with IR oxycodone and oxycodone plus APAP (both approximately 7 hours). Typical adverse events, particularly somnolence, occurred in all active treatment groups. Treatment with CR oxycodone was safe and effective in this study, and its characteristics will be beneficial in the treatment of pain.

Using the radionuclide salivagram to detect pulmonary aspiration and esophageal dysmotility

That the radionuclide "milk" scan is insensitive for aspiration has been demonstrated. Here the authors review their experience with the radionuclide salivagram in its ability to detect aspiration in children. Tc-99m sulfur colloid, 0.5 to 1.0 mCi in less than 1 mL, is instilled into the mouth and sequential supine posterior images of the thorax are obtained for an hour with delayed images until the oropharynx is cleared of radiotracer. Fourteen studies have been performed in 13 patients aged 1 month to 6.5 years. There are scintigraphic findings consistent with aspiration in 4 of 14 studies (28%); dysmotility (prolonged retention of activity in the esophagus) in 7 of 14 studies (50%); and normal studies in 3 of 13 patients (22%). Eight of 13 patients had milk scans; all were negative for aspiration. One patient studied twice had aspiration on the first examination, and dysmotility on the second study. It is concluded that the salivagram can detect aspiration of oral secretions, is superior to the milk scan in detecting aspiration, and can demonstrate esophageal dysmotility.

Scorpion venom leads to gastrointestinal ischemia despite increased oxygen delivery in pigs

OBJECTIVES

Scorpion envenomation may be accompanied by metabolic acidosis even in the absence of hypoxia and cardiovascular derangement. We tested the hypothesis that venom causes ischemia of the gastrointestinal tract rather than failure of delivery of oxygen to the periphery.

DESIGN

Repeated measures, prospective study in experimental animals.

SETTING

University-affiliated hospital research laboratory.

INTERVENTIONS

In ten spontaneously breathing, intubated, sedated pigs, purified dried venom (Leiurus quinquestriatus), 0.05 mg/kg, was administered intravenously. Measurements were obtained before (baseline), and 5, 15, 30, 60, 120, 180, and 240 mins after injection.

MEASUREMENTS AND MAIN RESULTS

Variables measured included: mean arterial pressure (MAP), heart rate (HR), mean pulmonary arterial pressure, pulmonary artery occlusion pressure, cardiac output, stroke volume, right ventricular ejection fraction (rapid thermistor), left ventricular dimensions (echocardiography), arterial gas tensions, lactate and catecholamine concentrations, gastric interstitial mucosal pH (tonometry), as well as systemic and pulmonary vascular resistances. Within 5 mins after venom injection, there was a hyperdynamic state accompanied by significantly increased MAP (97 +/- 18 to 136 +/- 47 mm Hg, p < .0003), HR (70 +/- 12 to 121 +/- 24 beats/min, p < .00006), and cardiac output (1.88 +/- 0.35 to 2.95 +/- 0.53 L/min, p < .0003), with no change in stroke volume, or pulmonary artery occlusion pressure. Right ventricular ejection fraction increased from 38.1 +/- 4.3 to 48.6 +/- 9.0% (p < .0009) by 15 mins. No change in left ventricular function was observed. There were significant decreases in systemic vascular resistance and pulmonary vascular resistance following envenomation. Arterial and gastric mucosal pH significantly decreased from 7.40 +/- 0.04 to 7.25 +/- 0.07 (p < .0001) for arterial pH, and 7.33 +/- 0.08 to 7.17 +/- 0.13 (p < .00001) for gastric mucosal pH by 30 mins after envenomation. The decrease in arterial pH was not sufficient to account for the change in gastric mucosal pH, indicating gastric mucosal ischemia. Arterial lactate increased from 2.6 +/- 1.4 to 7.4 +/- 1.9 (p < .05 x 10(-8)). There were significant increases in serum epinephrine and norepinephrine values by 5 mins. All hemodynamic variables and catecholamine concentrations returned to baseline by 4 hrs. However, there was persistent arterial and gastric mucosal acidosis and increased lactate concentrations even at 4 hrs. Oxygen delivery remained normal or supernormal for 4 hrs following envenomation. However, despite this finding, systemic and gastric mucosal pH changes indicate impaired gastrointestinal oxygen delivery.

CONCLUSIONS

Despite increased peripheral oxygen delivery, scorpion envenomation was associated with evidence of ischemia of the gastrointestinal tract. This association could be due to shunting of blood from metabolically active areas, possibly associated with massive catecholamine release, or a direct toxic effect of the venom on regional oxygen transport at the cellular level.

Evaluating wildlife as a potential source of Salmonella serotype Newport (JJPX01.0061) contamination for tomatoes on the eastern shore of Virginia

Eastern Shore of Virginia red, round tomatoes contaminated with Salmonella serotype Newport pattern JJPX01.0061 have been a source of several multistate outbreaks within the last 10 years. No source of the contamination has yet been identified. The goal of this study was to evaluate wildlife as a potential source of contamination. Faecal samples from deer, turtles and birds were collected between November 2010 and July 2011 from seventeen locations on the Eastern Shore of Virginia. A total of 262 samples were tested for the presence of Salmonella using an enzyme-linked immunosorbent assay (ELISA). A total of 23 (8.8%) samples tested positive for Salmonella spp. and were further characterized by serotyping and pulsed-field gel electrophoresis (PFGE) subtyping. Overall, twelve serotypes were identified, including Salmonella serotype Javiana, another common serotype associated with tomato-related outbreaks. Only one avian sample collected in July 2011 was determined to be positive for S. Newport pattern 61. This sample was collected from the ground at a site where birds, mostly gulls, were congregating. Although many of the avian samples from this site were dry, the site yielded eleven positive Salmonella samples. This suggests that certain Salmonella serotypes may persist in the environment despite extreme conditions. The recovery of one Newport pattern 61 isolate alone does not yield much information regarding the environmental reservoirs of this pathogen, but when combined with other data including the recovery of several isolates of Javiana from birds, it suggests that birds might be a potential source of Salmonella contamination for tomatoes on the Eastern Shore.

Analgesic efficacy of piroxicam in the treatment of postoperative pain

Two randomized, double-blind, single-dose studies were conducted to assess the analgesic efficacy and safety of piroxicam for the treatment of moderate or severe postoperative pain. Study 1 evaluated the analgesic efficacy of piroxicam 20 mg compared with that of codeine sulfate 60 mg and placebo. A final patient population of 149 subjects rated pain intensity and pain relief at one half hour and one hour following treatment and then hourly for six hours, with a global assessment made at the completion of 24 hours. Piroxicam 20 mg was significantly more efficacious than placebo for all analgesic variables, including the sum of the pain intensity differences (SPID), total pain relief (TOTAL), percent SPID, duration of effect, and time to remedication. Codeine 60 mg was significantly superior to placebo for percent SPID and some hourly measures. Piroxicam 20 mg was significantly more effective than codeine 60 mg for percent SPID and a few hourly measures including time to remedication. Study 2 assessed the efficacy of piroxicam 20 mg or 40 mg compared with aspirin 648 mg and placebo. Sixty patients rated their pain intensity and relief hourly for 12 hours and at 24 hours after administration of study medication. Both doses of piroxicam were significantly more effective than placebo from Hours 2 to 12 for pain intensity difference (PID) and relief scores, as well as for SPID and TOTAL. Aspirin was significantly more effective than placebo from Hours 2 to 8 for relief and Hours 2 to 10 for PID as well as SPID and TOTAL. Piroxicam 40 mg was significantly more effective than aspirin 648 mg for SPID, TOTAL, and hourly measures beginning with Hour 6 through Hour 12. Piroxicam 20 mg was significantly better than aspirin for a few hourly measures: Hours 7 to 9 for relief and Hour 7 for PID. In addition, effects of piroxicam 20 mg had a significantly longer duration than aspirin. Similarly, piroxicam 20 mg had a significantly longer time to remedication compared with aspirin and placebo. The results of these studies provide evidence in support of the longer duration of analgesic efficacy of piroxicam compared with codeine or aspirin in patients with postoperative pain.

Retrospective evaluation of a potential interaction between azithromycine and warfarin in patients stabilized on warfarin

STUDY OBJECTIVE

To investigate a potential interaction between azithromycin and warfarin.

DESIGN

Retrospective case-control study.

SETTING

Veterans Affairs medical center.

PATIENTS

Fifty-two patients stable on anticoagulation therapy.

INTERVENTION

Patients who received a prescription for azithromycin and warfarin at any time since the hospital was opened, June 1, 1995, to July 22, 1999, were identified through a computerized report generated from the pharmacy prescription package.

MEASUREMENTS AND MAIN RESULTS

Patients having a stable international normalized ratio (INR; defined as a therapeutic INR +/- 0.2) for at least two consecutive visits before receiving an azithromycin prescription were reviewed. Changes in INR from before and after addition of azithromycin were compared with changes in a control group. Controls were identified from a computer-generated report of patients who received a prescription for terazosin and warfarin at any time since the hospital was opened to July 22, 1999 (terazosin was chosen as it has no known interaction with warfarin). These patients also had a stable INR for at least two consecutive visits before receiving the terazosin prescription. In patients with INRs on record within 14 days after starting azithromycin or terazosin (9 patients/group), the average change in INR was 0.18 +/- 0.48 in the azithromycin group and 0.07 +/- 0.49 in the terazosin group (p=0.60). For patients with an INR on record within 30 days after starting azithromycin or terazosin (26 patients/group), the average change in INR was 0.25 +/- 0.67 in the azithromycin group and 0.05 +/- 0.55 in the terazosin group (p=0.18).

CONCLUSION

An interaction between azithromycin and warfarin was not observed in this retrospective review of patients with a stable INR receiving the combination.

Visual field deficits after epilepsy surgery: a new quantitative scoring method

Background

Anterior temporal lobectomy (ATL) as a treatment for drug-resistant temporal lobe epilepsy (TLE) frequently causes visual field deficits (VFDs). Reported VFD encompasses homonymous contralateral upper quadrantanopia. Its reported incidence ranges from 15 to 90%. To date, a quantitative method to evaluate postoperative VFD in static perimetry is not available. A method to quantify postoperative VFD, which allows for comparison between groups of patients, was developed.

Methods

Fifty-five patients with drug-resistant TLE, who underwent ATL with pre- and postoperative perimetry, were included. Temporal lobe resection length was measured on postoperative MRI. Percentage VFD was calculated for the total visual field, contralateral upper quadrant, or other three quadrants combined.

Results

Patients were divided into groups by resection size (< 45 and ≥ 45 mm) and side of surgery (right and left). We found significant higher VFD in the ≥ 45 vs. < 45 mm group (2.3 ± 4.4 vs. 0.7 ± 2.4%,p = 0.04) for right-sided ATL. Comparing VFD in both eyes, we found more VFD in the right vs. left eye following left-sided ATL (14.5 ± 9.8 vs. 12.9 ± 8.3%, p = 0.03). We also demonstrated significantly more VFD in the < 45 mm group for left- vs. right-sided surgery (6.7 ± 6.7 vs. 13.1 ± 7.0%, p = 0.016). A significant quantitative correlation between VFD and resection size for right-sided ATL was shown (r = 0.52, p < 0.01).

Conclusions

We developed a new quantitative scoring method for the assessment of postoperative visual field deficits after temporal lobe epilepsy surgery and assessed its feasibility for clinical use. A significant correlation between VFD and resection size for right-sided ATL was confirmed.

Analgesic effects of oral propiram fumarate, codeine sulfate and placebo in postoperative pain

Our purpose was to evaluate the analgesic efficacy and safety of single oral doses of propiram fumarate 50 mg, codeine sulfate 60 mg and placebo in the relief of moderate to severe postoperative pain. One hundred and twenty patients completed a randomized, double-blind, single-dose, stratified, parallel-groups trial and were observed for either 4 or 6 hours. Based upon each of the summary efficacy measures--SPID, % SPID and TOTAL--propiram and codeine were approximately equally effective and both were statistically superior to placebo. Propiram was significantly more effective than codeine at hour 5 for Pain Intensity Difference. Two adverse effects were attributed to propiram. Propiram fumarate 50 mg is an effective oral analgesic similar to codeine sulfate 60 mg, with the possibility of a longer duration of action.

Acetylation of synaptosomal protein: effect of Na+

In a previous study it was shown that the acetyl moiety can be incorporated into the protein of purified synaptosomes (1). This process was inhibited by veratridine and the inhibitory effect was counteracted by tetrodotoxin. This suggested that the flux of Na+ may be related to the acetylation process. We now report that in a sodium free medium the amount of acetylation is increased and the inhibitory effect of veratridine (veratrine) is no longer evident. The addition of Na+ leads to a decrease in acetylation in the presence of veratrine. The presence of scorpion toxin has an effect similar to that of veratrine and the two are not additive. Hence, they appear to act on a common site. Molecular sieve chromatography shows four radioactively labeled peaks, two of which are particularly affected by veratrine. We also show that [3H]acetate incorporated into synaptosomal protein can be recovered as acetyldansylhydrazide. In addition, the concentration of free and bound acetate was measured in whole brain as well as in synaptosomes.

Water treatment membranes embedded with a stable and bactericidal nanodiamond material

Filtration has emerged as a critical technology to reduce waterborne diseases caused by poor water quality. Filtration technology presents key challenges, such as membrane selectivity, permeability and biofouling. Nanomaterials can offer solutions to these challenges by varying the membranes' mechanical and bactericidal properties. This research uses nanodiamond particles with facile surface functionality and biocompatibility properties that are added to membranes used for filtration treatments. Scanning and transmission electron microscopy (SEM and TEM) and Fourier transform infrared spectroscopy (FTIR) were performed to study the membrane surface. FTIR spectra confirms an increase in oxygen functional groups onto the ultradispersed diamond's (UDD) surface following acid treatment. SEM images show particle deagglomeration of functionalized UDD at the membrane surface. Tensile strength tests were done to measure the UDD mechanical properties and Coliscan membrane filtration characterization was performed to determine the filter effectiveness. Polyether sulfone (PES) and polyvinylidene (PVDF) membranes expressed a change in their yield point when UDD was incorporated into the porous matrix. A significant microorganism reduction was obtained and confirmed using t-test analysis at a 95% level of confidence. UDD-embedded membranes exhibit a significant bactericidal reduction compared to commercial membranes suggesting these membranes have the potential to enhance current membrane filtration systems.

Novelty processing depends on medial temporal lobe structures

OBJECTIVES

The goal of the present study was to identify the role of the medial temporal lobe (MTL) in the detection and later processing of novelty.

METHODS

Twenty-one epilepsy patients with unilateral MTL resection (10 left-sided; 11 right-sided) and 26 matched healthy controls performed an adapted visual novelty oddball task. In this task two streams of stimuli were presented on the left and right of fixation while the patients' electroencephalogram was measured. The participants had to respond to infrequent target stimuli, while ignoring frequent standard, and infrequent novel stimuli that were presented to the left or right, appearing either contra- or ipsilateral to the patients' resections.

RESULTS

Novelty detection, as indexed by the N2 ERP component elicited by novels, was reduced by the MTL resections, as evidenced by a smaller N2 for patients than healthy controls. Later processing of novels, as indexed by the novelty P3 ERP component, was reduced for novels presented contra- versus ipsilateral to the resected side. Moreover, at a frontal electrode site, the N2-P3 complex showed reduced novelty processing in patients with MTL resections compared to healthy controls. The ERP differences were specific for the novel stimuli, as target processing, as indexed by the P3b, was unaffected in the patients: No P3b differences were found between targets presented ipsi- or contralaterally to the resected side, nor between patients and healthy controls.

CONCLUSIONS

The current results suggest that MTL structures play a role in novelty processing. In contrast, target processing was unaffected by MTL resections.