Intraspinal analgesia: a new route for an old drug

Chronic pain control is a pressing world health problem. Despite the magnitude of this health issue, health care professionals receive little formal training in pain management, hence attempts to deal with chronically suffering patients may be futile. A new intervention, the infusion of low-dose spinal opiates via a totally implanted continuous flow pump, is providing a new approach to pain control and offering a desirable alternative to the need for escalating systemic narcotics and neuroablative procedures. A brief overview of the anatomy and physiology of the pain mechanism will be discussed as well as rationale for the use of continuous infusion of spinal opiates. Nursing interventions for the patient receiving intraspinal analgesia will also be discussed.     

Sphingomyelin/cholesterol liposomal vincristine: a new formulation for an old drug

Sphingomyelin/cholesterol liposomal vincristine (SV) is a novel formulation of vincristine encapsulated in the aqueous interior of liposomes composed of sphingomyelin and cholesterol. Benefits of the liposomal formulation include prolongation of the circulation half-life of total vincristine and an increase in drug delivery to sites of tumour growth resulting in enhanced efficacy. In addition, higher doses of vincristine than ordinarily administered can be prescribed without significant toxicity. Phase II studies have demonstrated that SV is active and well tolerated in relapsed diffuse large B cell lymphoma (DLBCL), including patients who have relapsed following an autologous stem cell transplant. SV has been successfully substituted for free vincristine in the CHOP regimen for those with previously untreated aggressive B cell non-Hodgkin's lymphoma, and is undergoing study in other settings. The achievement of responses in heavily pretreated patients with DLBCL and its low toxicity profile make SV a potential therapy for the palliative treatment of patients with multiply relapsed DLBCL. Ultimately, it is likely to be incorporated into combination chemotherapy regimens for use in untreated or relapsed patients. Its true value both as a single agent in heavily pretreated patients and in combination regimens will need to be established in Phase III trials.     

Portal hypertension. A new beginning for an old problem.

There are two types of shunts for the treatment of esophageal varices: total shunts or selective shunts. The various total shunts are designed to "decompress" both the portal and the variceal venous systems. In contrast, a selective shunt decompresses the varices only, and the portal pressure and presumably portal flow are not affected. The very purpose of the total shunt is the total or partial diversion of portal flow. This is the case no matter which branches of the portal and systemic venous systems are connected and whether the anastomosis is a direct one or is through a graft. In an ongoing prospective, randomized clinical trial, which now includes 46 patients, a total shunt (mesorenal H graft) and the selective distal splenorenal (Warren) shunt are compared. The operative mortality rate and the frequency of postoperative bleeding are the same. However, encephalopathy is more frequent after the total shunt (P less than 0.05), and a trend is developing which suggests a better long-term survival rate after the Warren shunt. If these trends continue, then the superiority of the Warren shunt is established in a selected group of patients who have bled at least once from their varices. If these patients continue to remain free of encephalopathy and hemorrhage will not recur, then it is probable that the Warren shunt could improve the chances of survival of cirrhotic patients with esophageal varices who did not bleed yet. The "prophylactic" value of the Warren shunt will require a multicenter, cooperative, controlled clinical trial.     

Chloral hydrate for emergent pediatric procedural sedation: a new look at an old drug

Chloral hydrate has been time honored for pediatric procedural sedation, but its efficacy in sedation for emergency department (ED) procedures is unreported. It is hypothesized that chloral hydrate is safe and effective for ED pediatric sedation. Ninety-five consecutive children ranging from 1-10 years and requiring procedural intervention in a municipal teaching hospital ED were included in a nonrandomized controlled trial. Patients with respiratory depression, somnolence, allergy, multisystem trauma, head injury, or abdominal pain were excluded. Forty-two subjects received chloral hydrate 25 to 50 mg/kg orally at physician discretion, and 53 subjects served as controls. Cooperation with procedural completion was rated by the treating physician using the four-point sedation scoring system modified from Moody et al (1 = poor, 4 = excellent). The two groups' sedation scores were compared by the Mann Whitney U test with significance at P less than .05. Age-related subgroups of children were similarly compared. The treatment group achieved sedation score of 2.86, whereas controls had sedation score of 2.75 (P = 0.63, beta error 20% at 0.37 score difference). Subgroup analysis of children less than 6 years old (2.95 experimental versus 2.57 control) and less than 4 years old (3.00 experimental versus 2.32 control) reveals statistically significant differences (P less than .0001 and P = .01, respectively) in favor of higher sedation scores in the chloral hydrate group. Time to sedation was 42.7 minutes, time to recovery was 42.0 minutes, and no adverse drug effects were noted.(ABSTRACT TRUNCATED AT 250 WORDS)     

A new design for an old concept of wheelchair pushrim

Purpose: Report on the development of an ergonomic manual wheelchair pushrim and evaluate the user’s perception of the quality of the device. Method: Based on anthropometric features and ergonomic concepts, a new wheelchair pushrim was designed, and a prototype was manufactured in polyurethane, using the rapid prototyping technique and serial production of parts by molding. The prototype was tested by a sample of wheelchair users, who rated the perceived quality of the device after testing both the new and conventional pushrims in a wheelchair propulsion experimental protocol. Results: The new ergonomic pushrim was found to be, in general, better than the conventional round tube pushrim. Specifically, experienced wheelchair users found the new wheelchair pushrim better in terms of easy and comfortable propulsion, braking and maneuvering of the wheelchair, and appearance. Conclusions: The new wheelchair pushrim provides a proper fit for the hands due to its ergonomic design and its polyurethane composition, making wheelchair propulsion easier and more comfortable than the conventional wheelchair pushrim. Assistive technology devices should be design based on ergonomic concepts that involve less effort and offer greater comfort for the user.

Implications for Rehabilitation

• Manual wheelchair propulsion has been related with upper limb injuries that may potentially limit functionality.

• The conventional pushrim does not meet the need for a firm and stable grip, requiring further effort to hold the pushrim during manual propulsion that may cause discomfort, pain and contribute for developing upper limb injuries.

• In a relatively small sample of wheelchair users, this study shows that an ergonomically designed pushrim makes manual propulsion easier and more comfortable compared to the conventional pushrim.

     

Inhibition of tissue factor expression by hydroxyurea in polymorphonuclear leukocytes from patients with myeloproliferative disorders: a new effect for an old drug?

BACKGROUND: Polymorphonuclear leukocytes (PMN) from healthy subjects can produce and store tissue factor (TF), which is expressed on PMN surface upon in vitro stimulation with P-selectin. RESULTS: We report here that platelets and PMN from 12 patients with myeloproliferative disorders (MPD) (six with polycythemia vera, six with essential thrombocythemia) show up regulation of P-selectin and TF, respectively, in the absence of any in vitro challenge. The number of circulating mixed platelet-PMN aggregates was also increased. PMN TF expression as well as mixed platelet-PMN aggregates, but not platelet P-selectin, were significantly reduced in six MPD patients after treatment with hydroxyurea (HU). In vitro studies performed on PMN separated from healthy donors confirmed HU effects (0-1400 microm). HU prevented both P-selectin-induced TF expression and mixed cell aggregate formation. The inhibitory effect of HU was specific for P-selectin-induced PMN activation, as it did not affect formyl-methionyl-leucyl-phenylalanine-induced PMN TF expression. CONCLUSIONS: In MPD patients, platelet P-selectin-mediated TF expression on circulating PMN may play a role in thrombus formation and represents a novel target for the antithrombotic activity of HU.