Preoperative Clinical Assessment of Hemostatic Function in Patients Scheduled for a Cardiac Operation

Background. Bleeding during and after cardiac operations is usually attributed to inadequate surgical hemostasis or cardiopulmonary bypass-induced disorders of hemostasis. Patient-related factors often are neglected.

Methods. Articles published between 1976 and 1996 on the preoperative assessment of surgical patients were reviewed to determine the clinical elements most likely to predict increased perioperative blood requirements.

Results. Preoperative assessment is based on a carefully conducted interview (history of bruising, petechiae, recent or excessive bleeding after operation, chronic drug therapy) and physical examination. A standardized questionnaire to enhance the reliability of the assessment is presented. Thus, patients at high risk of being transfused can be identified early on and may be enrolled in various programs designed to decrease bleeding and the need for allogeneic blood transfusions.

Conclusions. Clinical assessment of hemostatic function before cardiac operations is both effective and efficient. It obviates the need for routine laboratory testing and favors the introduction of blood conservation strategies early on during the process of care.     

The quantitative distinction between train-of-four "counts of 2" and posttetanic "counts of 2" evidenced by a stable paralysis/stable infusion rate method in anesthetized patients receiving mivacurium

In this study we quantitatively evaluated, by a stable paralysis/stable infusion rate method, the difference between two standardized paralysis levels--train-of-four (TOF) count of 2 responses and posttetanic count (PTC) of 2. Ten ASA physical status I-II consenting adult patients scheduled for elective surgery were anesthetized (sufentanil/propofol), tracheally intubated, mechanically normoventilated with a fixed O(2)/air mixture, and normothermic; oropharynx and thenar temperatures were maintained above 36 degrees and 32.5 degrees C, respectively. After partial recovery from 200 microg/kg mivacurium (MIV), stable tactile TOF and PTC counts of 2 paralysis levels were induced on the adductor pollicis muscle by manual adjustments of an infusion pump containing MIV. The paralysis levels and the infusion rates were considered as stable once they remained constant at 4 consecutive time points separated by 5 min each. Infusion rates observed were: TOF count 2-6 (2-11) and PTC 2-17 (3-18) microg . kg(-1) . min(-1) (P < 0.001; Wilcoxon's paired comparison test). Under the present conditions, obtaining and maintaining a PTC of 2 requires MIV infusion rates far in excess of the "standard" recommendations mentioned in the literature for MIV infusion management.     

Use of dual transarticular screws to fixate simultaneous occipitoatlantal and atlantoaxial dislocations

Occipitoatlantal dislocation and atlantoaxial vertical distraction are caused by similar mechanisms, and few individuals survive these injuries. It is hypothesized that the injurious vertical force manifests as a traumatic lesion at different levels of the same ligamentous complex. The authors report the cases of two patients who presented with this combined lesion, describe surgical alternatives for stabilization, and introduce a new technique that combines the use of transarticular screws in a "dual" construct, without involving the unaffected spine.     

Are there reliable predictors of postoperative pain?

BACKGROUND: The purpose of this study was to identify the preoperative determinants of severe postoperative pain. METHODS: Potential predictors were assessed using a questionnaire submitted on the day before surgery. Pain at rest, and pain during coughing/mobilization, were measured using visual analog scales on the day of surgery and on the following 2 days. The type of postoperative pain management was not standardized and was prescribed by the anesthesiologist in charge. Multivariate logistic regression models explaining postoperative pain were developed in Group I, comprising 304 consecutive patients undergoing orthopedic or intraperitoneal surgery, and validated in Group II, comprising 145 independent patients. RESULTS: Of the 62 variables examined by univariate analysis, only five were found to increase the risk of severe postoperative pain in Group I at rest and six factors during cough/mobilization. In the multivariate model for pain at rest, general anesthesia, expectation of postoperative pain, and chronic sleeping difficulties increased the risk of severe postoperative pain. In Group II, only chronic sleeping difficulties remained (OR: 3.97, 95% Cl: 1.69-9.29). In the multivariate model during cough/mobilization, intraperitoneal surgery, fear of postoperative pain, and having a relative with a history of pain increased the risk of severe postoperative pain in Group I. Intraperitoneal surgery OR 2.45 (95% Cl = 1.01-4.50) and having a relative with a history of pain OR 2.06 (95% Cl = 1.005-4.50) remained in Group II. CONCLUSION: Of the many factors that may influence postoperative pain, chronic sleeping difficulties emerge in this population of patients as the strongest determinant of pain at rest. Intraperitoneal surgery and having a relative with a history of pain are the strongest determinants of pain during cough/mobilization. These findings make physiological sense and deserve more attention by anesthesiologists.     

Children grow and horses race: is the adiposity rebound a critical period for later obesity?

Background  

The adiposity rebound is the second rise in body mass index that occurs between 3 and 7 years. An early age at adiposity rebound is known to be a risk factor for later obesity. The aim here is to clarify the connection between the age at rebound and the corresponding pattern of body mass index change, in centile terms, so as to better understand its ability to predict later fatness.     

A diagnostic strategy to determine the Shiga toxin-producing Escherichia coli O157 status of pens of feedlot cattle

Although cattle are reservoirs, no validated method exists to monitor Shiga toxin-producing Escherichia coli O157 (STEC O157) on farms. In 29 Midwestern United States feedlot pens we compared culturing faeces from the individual cattle to: (1) culturing rope devices that cattle rub or chew; and (2) culturing a composite of faecal pats. Eighty-six per cent (68-96%) of pens were classified correctly using rope devices to detect pens with at least 16% of the cattle shedding STEC O157 [sensitivity=82% (57-96%); specificity=92% (62-100%)]. Ninety per cent of pens (73-98%) were classified correctly using composite faeces to detect pens with at least 37% of the cattle shedding STEC O157 [sensitivity=86% (42-100%); specificity=91% (71-99%)]. Ranking pens into three risk levels based on parallel interpretation of the pen-test results correlated (Spearman's r=0.76, P<0.0001) with the pen's prevalence. This strategy could identify pens of cattle posing a higher risk to food safety.     

Decreased shedding of Escherichia coli O157:H7 by cattle following vaccination with type III secreted proteins

Cattle are an important reservoir of Escherichia coli O157:H7 leading to contamination of food and water, and subsequent human disease. This pathogen colonizes its hosts by producing several proteins such as Tir and EspA that are secreted by a type III secretion system. These proteins play a role in colonization of the intestine, suggesting that they might be useful targets for the development of a vaccine to reduce levels of this organism in cattle. Vaccination of cattle with proteins secreted by E. coli O157:H7 significantly reduced the numbers of bacteria shed in feces, the numbers of animals that shed, and the duration of shedding in an experimental challenge model. Vaccination of cattle also significantly (P=0.04) reduced the prevalence of E. coli O157:H7 in a clinical trial conducted in a typical feedlot setting. This strategy suggests it is possible to vaccinate cattle to decrease the level of E. coli O157:H7 shedding for the purpose of reducing the risk of human disease.