Pain and the administration of analgesia: what nurses say

? Pain of moderate to severe intensity continues to be an important problem for many hospitalized patients. ? Nurses spend more time with patients than any other health professional group and have a key role to play in the management of patients' pain. ? This paper reports the findings from a series of focus group interviews which were undertaken to explore nurses' perceptions regarding pain and the administration of narcotic analgesia. ? Themes identified from participants' comments related to (1) the pivotal role of nurses in pain management; (2) nursing assessment and pain management decisions (3) individual factors influencing nurses' pain management decisions and (4) the influence of others on nurses' pain management decisions. ? These findings have implications for further research and the development of innovative educational strategies.     

Antigen topography is critical for interaction of IgG2 anti-red-cell antibodies with Fcγ receptors

IgG antibodies to the Rh D polypeptide on red cells are normally IgG1 or IgG3, whereas antibodies produced in response to carbohydrate antigens such as the A and B blood groups are predominantly IgG2. The consequences of this isotype restriction for the immune destruction of red cells were investigated. Human IgG2 anti-D and IgG2 anti-A were isolated by affinity purification from an unusual anti-D serum (DEL) and anti-A sera, respectively. These antibodies were compared with IgG1 and IgG3 monoclonal anti-D in in vitro functional assays of the interaction between IgG-coated red cells (EA-IgG) and cells bearing IgG Fc receptors (FcγR). Dimeric IgG2 anti-D bound efficiently to cell lines transfected with FcγRIIa-H131, an allotypic form of FcγRIIa which readily interacts with IgG2, IgG1 and IgG3. Unexpectedly, however, -D-phenotype red cells coated with IgG2 anti-D did not form rosettes with these cells, whereas EA-IgG2 anti-A and EA-IgG1 and EA-IgG3 anti-D effectively formed rosettes with these transfectants at the same sensitization level (100 000 molecules IgG/red cell). In antibody-dependent cell-mediated cytotoxicity (ADCC) assays, lysis of EA-IgG2 anti-A was mediated via FcγRIIa, whereas lysis of EA-IgG1 and EA-IgG3 anti-D was mediated via FcγRI or FcγRIII; EA-IgG2 anti-D was inactive in all functional assays. These experiments suggest that both IgG subclass and antigen structure affect functional IgG–FcγR interactions. The topography of the Rh D antigen, an integral membrane protein, ensures that anti-D is bound near the lipid bilayer surrounded by the glycocalyx. This may sterically hinder access of FcγRIIa-H131 to the FcγR recognition site on the relatively inflexible IgG2 anti-D, but not to that of IgG1 or IgG3 anti-D. In contrast, IgG2 bound to the A antigen on glycoproteins is not so constrained. The topography of the D and A antigens may thus determine whether functional interactions of red-cell-bound IgG2 anti-D and IgG2 anti-A with cells bearing Fcγ receptors can occur.     

ENDOSCOPY

Abstract Current antibiotic prophylaxis for endoscopic retrograde cholangiopancreatography (ERCP) is not standardized and may be inadequate. We aimed to evaluate the efficacy of 3 days of additional oral antibiotics in the prevention of ERCP-related sepsis. One hundred and fifty-six patients were randomized prospectively to receive either intravenous ticarcillin and clavulinic acid (Timentin® SmithKline Beecham, Dandenong, Victoria, Australia), pre-ERCP (group I) or Timentin® and 3 days of oral amoxycillin and clavulinic acid (Augmentin®; SmithKline Beecham, Dandenong, Victoria, Australia), group II). Blood cultures were taken 30 min after the procedure. The occurrence of sepsis, defined as a temperature over 38°C, occurring in the first 7 days was recorded and the risk factors for the development of sepsis were evaluated. Four patients had significant positive blood cultures despite the prior administration of Timentin.® Sepsis occurred in 10% of group I patients, but only 3% of group II patients (relative risk 3.30; 95% confidence intervals 0.74-14.8). The performance of sphincterotomy and the presence of common bile duct stones were significant risk factors for the development of sepsis. We would recommend 3 days of additional oral Augmentin® after a single dose of intravenous antibiotics in patients at increased risk of sepsis, which would include those with bile duct stones and/or those undergoing a therapeutic procedure.     

Complications of Implantable Cardioverter Defibrillator Therapy: Follow-Up of 241 Patients

In order to determine the incidence of complications of impJantable cardioverter defibrillator (ICD) therapy, 241 patients with a total of 353 ICD implantations were followed for 24 ± 20 months. Complications were defined as any untoward effects experienced by the patient related to the ICD implantation and function or death within 4 weeks of implant or before hospital discharge. During follow-up, 129 of 241 patients (53%) had a total of 166 complications. An operative procedure was required to correct the complication in 50 of the 241 patients (21%). No patient died intraoperativeiy, but eight patients died within 4 weeks postoperatively or before hospital discharge. ICD infection required removal of the device in 13 patients (5%). Twenty-six patients (11%) had postoperative respiratory complications. Postoperative bleeding and/or thrombosis occurred in 11 patients (4%). Endocardial lead migration was observed in nine patients (4%) and lead adapter or insulation break occurred in nine patients (4%). Fifty-four patients (22%) experienced ECC-documented discharges for non-VT rhythm. In conclusion, although perioperative mortality in ICD patients is low, the maiority of patients have complications during followup. Recognition of these complications may allow for advances in ICD technology and management strategies to avoid their occurrence.     

A survey of in situ sarcomere extension in mouse skeletal muscle

The giant molecule titin/connectin was demonstrated to connect the ends of thick filaments with the Z-disks and thus to provide an elastic connection that seems to be responsible for passive tension in striated muscle. To investigate the physiological limits of I-band titin extension in skeletal muscle, we have measured sarcomere lengths of a number of mouse postural and clonal muscles in situ under the constraints imposed by the skeletal, ligamentous and tendinous components of the motile apparatus. These values now give upper limits for the extension of the I-band and therefore for the maximal degree of titin extension under physiological constraints. We find that I-band extension in all muscles investigated does not exceed a factor of 2.5 in situ, which is well below values obtainable in isolated fibre preparations. Approach to the yield-point is therefore prevented by extramuscular mechanisms. Sarcomere lengths near the tendinous junction and within the muscle are virtually identical in extended muscle, suggesting that a major function of titin in intact muscle is to ensure uniform sarcomere lengths over the entire muscle length and thus to prevent localized myofibril overstretch during isometric contraction     

Quantitative Evaluation of Hepatic Foci of Cellular Alteration Occurring Spontaneously in Fischer-344 Rats

Quantitative Evaluation of Hepatic Foci of Cellular AlterationOccurring Spontaneously in Fischer-344 Rats. Popp, J. A., SCORTICHINI,B. H., AND GARVEY, L. K. (1985). Fundam. Appl. Toxicol. 5, 314–319.Stereologic procedures were used to quantitate spontaneouslyoccurring liver foci of altered staining in control Fischer-344rats at 33, 59, 85, and 111 weeks of age. Foci were identifiedusing hematoxylin and eosin stained sections. In both malesand females, foci were first observed at 59 weeks. The numberof foci per cubic centimeter of liver, as well as mean focalvolume, increased significantly with age. Between 85 and 111weeks, the number of foci per liver increased 3.5 times in femalesbut was unchanged in males. When three groups of 111-week-oldanimals were evaluated, females consistently had a greater numberof foci per cubic centimeter of liver and mean focal volumethan males of the same group. For the three groups evaluatedat 111 weeks, the mean number of foci per liver ranged from431 to 1865 in males and from 727 to 1654 in females. The meanvolume fraction (% of the liver) occupied by foci ranged from0.28 to 1.0% in males and from 1.42 to 4.15% in females. Whenfocal staining characteristics were investigated, the majorityof foci were basophilic in both sexes at all time points examined.However, males consistently had a higher percentage of eosinophilicfoci than females.     

Electrocardiographically Documented Unnecessary, Spontaneous Shocks in 241 Patients With Implantable Cardioverter Defibrillators

The incidence and cause of electrocardiographically documented spontaneous implantuble Cardioverter defibrillator (ICD) discharges for a rhythm other than ventricular tachycardia (VT) or fibrillation (VF) (unnecessary shocks) were determined in 241 patients who underwent ICD implantation between March 1983 and November 1991. During follow-up of 24 ± 20 months, 54 of 241 patients (22%) received a total of 132 unnecessary ICD shocks confirmed by Holler or telemetry monitoring or stored electrograms (Egs) from the ICD. The rhythm preceding these unnecessary ICD shocks was atrial fibrillation in 30 patients, sinus or supraventricular tachycardia (SVT) in 11 patients, antitachycardia pacing triggered by atrial fibrillation or SVT resulting in VT in 5 patients, nonsustained VT in 3 patients, and normal sinus or pacemaker rhythm in 10 patients. Unnecessary ICD discharges occurred most frequently during the first week after implantation or generator replacement (18 of 54 patients [33%]). Unnecessary ICD discharges could be documented more often by stored Egs in patients with devices with Eg storage capability (Ventritex Cadence(tm), 19 of 54 patients [35%]) than by Holter or telemetry monitoring in patients with devices without Eg storage capabilities (34 of 193 patients [18%], P < 0.01), despite a shorter mean follow-up duration of 14 ± 9 months versus 26 ± 21 months, respectively. Only six of 54 patients (11%) in whom unnecessary ICD discharges occurred had recurrent unnecessary shocks during 22 ± 20 months of follow-up after treatment directed at the cause of the first episode or device reprogramming to preclude non-VT rhythm detection. In conclusion, unnecessary ICD shocks are a frequent complication of ICD therapy occurring in at least 22% of patients. The cause of these shocks is most frequently atrial fibrillation with a rapid ventricular response. The availability of Eg storage capabilities facilitates the diagnosis of the electrical event precipitating inappropriate ICD shocks. Diagnosis of the cause of unnecessary shocks allows for the institution of therapy that may reduce the risk for subsequent events.     

Major Histocompatibility Antigens on Trophoblast and Their Regulation: Implications in the Maternal-Fetal Relationship

ABSTRACT: Recent technological advances have provided methods of detecting antigens encoded by the major histocompatibility complex with greater precision, allowing the expression of such antigens on the components of the placenta to be clarified. Of specific interest is the expression of these antigens on trophoblast cells, the fetal-derived epithelial cells that confront maternal blood and tissues at the maternal-fetal interface. It is now clear that the different trophoblast subpopulations differentially express class I antigens, although none appear to express class II antigens. Class I antigens can be induced by exposure to interferons on some populations but apparently not others, suggesting that the regulation of their expression differs for sub-populations of trophoblast cells, depending on gestational stage and location. This restricted expression has important implications for maternal-fetal immune interactions during the different phases of pregnancy and perhaps also bears on physiological functions of the feto-placental unit, such as growth and differentiation.     

Brugada Syndrome: A Heterogeneous Disease with a Common ECG Phenotype?

Our understanding of Brugada syndrome (BrS) has evolved since the syndrome was first described in 1992. BrS is considered to be a primary inherited channelopathy often involving the inward sodium current and the diagnosis has traditionally required the exclusion of overt structural heart disease. In view of recently published observations about BrS, we propose that the term BrS may actually encompass a heterogeneous group of disorders with a variety of genetic and clinical phenotypes. This disease has classically been described as a primary electrical disorder involving the sodium channel leading to the characteristic electrocardiogram (ECG) changes of BrS. We challenge the current understanding and propose that patients with structurally normal hearts, family history of sudden cardiac death, with associated genetic abnormalities only account for a subset of patients with the “Brugada pattern” ECG. There may also be some patients with a diagnosis of BrS who may also have features which overlap with arrhythmogenic right ventricular cardiomyopathy. In these patients there may be an underlying structural abnormality. In this context, it is possible that catheter ablation may abolish the “Brugada pattern” ECG changes as well as abolishing the risk of life threatening arrhythmias in these patients. Given the recent developments in the field, we propose a novel comprehensive multimodality model for risk stratification and assessment of patients with BrS. Identification of variations of diseases may facilitate more specific risk stratification models and management paradigms in patients with Brugada ECG pattern.