A multidimensional comparison of morphine and hydromorphone patient-controlled analgesia.

Although patient-controlled analgesia (PCA) pumps have been in use for more than a decade, the optimal PCA analgesic has yet to be identified. Many drugs are used; however, morphine remains the "gold standard" of opioid analgesics worldwide. The present study evaluated morphine and hydromorphone (Dilaudid) PCA with respect to analgesic efficacy, side effects, mood, and cognitive function. Sixty-one opioid naive patients undergoing lower abdominal surgery participated in the double-blind protocol. Verbal rating scores, use of medication, and side effects for the two medications were recorded. Cognitive functioning was assessed by computation of Digit Symbol and Trails Making B Tests. Self-reported affective state (mood) was measured by Profile of Mood States (POMS) inventory. Both medications provided adequate analgesia without a difference in side effects. Cognitive performance was poorer in the hydromorphone group (P < 0.05). Patients receiving hydromorphone reported less anger/hostility (P < 0.01) and generally better mood elevations on the other subscales than those receiving morphine. A similar incidence of side effects and dose medication can be anticipated with morphine and hydromorphone. When considering cognitive effects, morphine had less adverse consequences, while hydromorphone appeared to result in improved mood. We conclude that hydromorphone may provide a suitable alternative to morphine.

Acute pain management of the chronic pain patient on opiates: a survey of caregivers at University of Washington Medical Center.

OBJECTIVE: The provision of acute pain management for the chronic pain patient can pose a challenge. We sought to characterize management issues. SUBJECTS/SETTING: An anonymous survey was distributed to 270 physicians and 212 nurses at University of Washington Medical Center (UWMC) in an attempt to characterize management issues. DESIGN: Caregivers were queried regarding treatment modalities, efficacy of anxiolysis, patient attributes, concern of the quantity of medication, criteria for patient evaluation, and other management issues. RESULTS: Of the respondents, 61.8% were physicians, and 38.2% were nurses. The mean duration in practice was 7.7 years. The responses from the two groups were similar. Seventy-five percent reported using different pain-evaluation techniques for chronic pain patients than those utilized for the "average" patient. Pain scores were used frequently in the average patient, whereas ability to perform activities was used more commonly in the chronic pain patient (p < 0.0001). Half of the respondents expressed concern regarding the amount of medication used and level of sedation. The same proportion found anxiolysis to be a helpful adjunct. The use of a time-contingent "pain cocktail" as an oral medication was a useful strategy for 88% of respondents. The least labor-intensive modality reported was patient-controlled analgesia (PCA) for 84.5% of respondents; intravenous opiate fusion, 5.3%; and epidural analgesia, 11.2%. CONCLUSIONS: The survey describes caregiver concerns regarding this patient population, including medication use, sedation, length of hospital stay, and evaluation techniques.

Chronic nitric oxide inhibition in utero produces persistent pulmonary hypertension in newborn lambs.

Persistent pulmonary hypertension of the newborn (PPHN) is associated with chronic intrauterine events. Acute nitric oxide (NO) inhibition attenuates the normal increase in pulmonary blood flow at birth. We investigated whether chronic NO inhibition in utero causes persistent pulmonary hypertension. 11 fetal lambs received either a continuous infusion of N omega-nitro-L-arginine (an NO synthesis inhibitor) or 0.9% saline. Before infusion, acetylcholine (dependent upon endogenous NO production) and sodium nitroprusside (which releases its own NO) produced potent pulmonary vasodilation. After 10.5 +/- 1.5 d of infusion, acetylcholine did not produce pulmonary vasodilation in N omega-nitric-L-arginine-treated fetal lambs, but did in saline-treated fetal lambs; sodium nitroprusside produced pulmonary vasodilation in both groups. Immediately after birth, at 140 d of gestation, during the 3-h study period, mean pulmonary arterial pressure did not decrease in N omega-nitro-L-arginine-treated lambs; the increase in pulmonary blood flow and decrease in pulmonary vascular resistance were markedly attenuated compared to saline-treated lambs. These hemodynamic derangements were reversed by L-arginine. There were no anatomic abnormalities in the pulmonary circulation. Chronic NO inhibition in utero reproduces many of the physiologic derangements of PPHN. Intrauterine events which result in endothelial dysfunction and inhibition of NO may produce the physiologic derrangements of PPHN.

Experimental human infection with Haemophilus ducreyi.

Four subjects were experimentally infected with Haemophilus ducreyi. Lesions developed only at sites where live bacteria were inoculated on abraded skin. No subject developed fever, lymphadenopathy, or disseminated infection during a 3-day observation period. Two subjects who were rechallenged 2 months after initial infection also developed lesions. The amount of H. ducreyi recovered from 10 of 12 biopsies that were semiquantitatively cultured varied widely. Similar histologic features were present in initial and second infections. The epidermis contained pustules; the dermis contained an infiltrate of T cells and macrophages and reactive endothelial cells. Keratinocytes and T cells expressed HLA-DR, consistent with a delayed-type hypersensitivity response. The subjects did not mount humoral responses to bacterial proteins and to lipooligosaccharides after primary and secondary challenges. Thus, human experimental infection with H. ducreyi is well tolerated and safe. Recruitment of T cells and macrophages into chancroid lesions may partially explain the association between chancroid and human immunodeficiency virus transmission.

Role of lipooligosaccharides in experimental dermal lesions caused by Haemophilus ducreyi.

The mouse and rabbit intradermal injection models have been used to define factors that may be important in Haemophilus ducreyi pathogenesis. We used H. ducreyi strains with diverse geographic origins and phenotypic characteristics to evaluate the experimental models. Injection of live and heat-killed bacteria caused skin abscesses in both models. Semiquantitative cultures of skin injected with live bacteria showed that H. ducreyi failed to replicate in animal tissue. These data suggested that the experimental lesions were caused by a heat-stable substance such as lipooligosaccharide (LOS). In mice, injection of H. ducreyi and Haemophilus influenzae LOS and Escherichia coli lipopolysaccharide caused mild to moderate inflammation. In rabbits, injection of H. ducreyi LOS caused intradermal abscesses that were histologically similar to those caused by live and heat-killed bacteria. H. ducreyi and Neisseria gonorrhoeae LOS caused significantly larger lesions than equivalent amounts of H. influenzae LOS and E. coli lipopolysaccharide in the rabbit model. We conclude that the intradermal injection models are not valid models to study the growth of H. ducreyi in vivo. However, these data indicate that H. ducreyi LOS may play an important role in the pathogenesis of chancroid and that the rabbit model should be useful in studying H. ducreyi LOS toxicity at the cellular level.

Alveolar hyperoxic injury in rabbits receiving exogenous surfactant.

We have previously demonstrated that instillation of a calf lung surfactant extract (CLSE) in rabbits after exposure to 100% O2 for 64 h mitigates the progression of lung pathology after return to room air (J. Appl. Physiol. 62: 756-761, 1987). In the present study, we investigated whether we could prevent or reduce the onset and development of hyperoxic lung injury by sequential instillations of CLSE during the hyperoxic exposure. Rabbits were exposed to 100% O2. CLSE (125 mg, approximately 170 mumol of phospholipid) was suspended in 10 ml of sterile saline and instilled intratracheally into their lungs, starting at 24 h in O2, a time at which no physiological or biochemical injury was detected, and at 24-h intervals thereafter. Control rabbits breathed 100% O2 and received either equal volumes of saline or no instillations at all. CLSE-instilled rabbits had higher arterial PO2 (Pao2) values throughout the exposure period and survived longer when compared with saline controls [120 +/- 4 vs. 102 +/- 4 (SE) h; n greater than or equal to 10; P less than 0.05]. At 72 h in O2, CLSE-instilled rabbits had significantly higher lavageable alveolar phospholipid levels (12.5 +/- 1.5 vs. 5 +/- 1 mumol/kg) and total lung capacities (41 +/- 2 vs. 25 +/- 3.5 ml/kg) and lower levels of alveolar protein (24 +/- 3 vs. 52 +/- 8 mg/kg), minimum surface tension (2 +/- 1 vs. 26.1 dyn/cm), and lung wet-to-dry weights (5.9 +/- 0.2 vs. 6.5 +/- 0.3). After 72 h in O2, lungs from both CLSE- and saline-instilled rabbits showed evidence of diffuse hyperoxic injury. However, atelectasis was less prominent in the former. We concluded that instillation of CLSE limits the onset and development of hyperoxic lung injury to the alveolar epithelium of rabbits.

Ligating the ductus arteriosus before birth remodels the pulmonary vasculature of the lamb.

The clinical syndrome of persistent pulmonary hypertension of the newborn includes a developmentally abnormal pulmonary microvasculature which contains excessive amounts of muscle and which cannot adapt to air breathing in the perinatal period. Surgical ligation of the ductus arteriosus of the fetal lamb has produced a physiologic model of pulmonary hypertension of the newborn. The aim of the present investigation is to determine whether surgical ligation of the ductus arteriosus in fetal sheep produces anatomic changes in the pulmonary blood vessels. The pulmonary vasculature of seven neonatal lambs that underwent surgical ligation of the ductus arteriosus from 6 to 17 d before birth was compared to that of five control lambs with a patent ductus arteriosus without fetal surgery and three control lambs with a patent ductus arteriosus that underwent sham surgery. Quantitative microscopic analysis of the barium gelatin-filled peripheral pulmonary vascular bed revealed an increase in the proportion of partially and fully muscularized pulmonary arteries at the level of the terminal bronchiole and within the acinus (p less than 0.0001). This finding demonstrates that medial muscle develops in areas of the distal pulmonary vascular bed where it is normally absent. Periadventitial fibrosis surrounding intraacinar pulmonary arteries was also present. No change in the number of small intraacinar arteries was detected. This structural remodeling of the peripheral pulmonary vascular bed was initiated in utero by ductus arteriosus occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular laceration due to stented prosthesis.

Complications following open chest massage in patients with porcine xenografts in the mitral location have not been previously described. The authors report a case of cardiac resuscitation following mitral valve replacement with a stented porcine valve. The patient died following brief closed chest, and then, prolonged open chest, cardiac massage. Autopsy showed laceration of the left ventricle by the prosthetic valve stents. Physicians involved in the postoperative care of patients with stented prosthetic valves should be aware of this complication and should exercise caution when applying manual compression in the region of the posterolateral base of the heart.