Efficacy of Red Cell Salvage Systems in Open Acetabular Surgery.

Over the past 50 years, treatment of displaced acetabular fractures has moved away from conservative treatment with bedrest to operative intervention to achieve anatomic reduction, stable fixation, and allow early range of motion of the hip. However, operative fixation is not without complications. Internal fixation of traumatic acetabular fractures has been coupled with large volume of blood loss both at the time of injury and surgery. This often results in the need for allogenic blood products, which has been linked to increase morbidity (Vamvakas and Blajchman, 2009). In an attempt to avoid the risk associated with allogenic blood transfusion numerous techniques and methods have been devised. Red blood cell salvage (CS) is an intraoperative blood salvage tool where blood is harvested from the operative field. It is washed to remove the plasma, white blood cells, and platelets. The red cells are resuspended in a crystalloid solution. If the hematocrit of the resuspended red blood cells is sufficient, it is transfused to the patient intravenously. The benefits of CS in major spine surgery, bilateral knee replacement, and revision hip surgery are well established (Goulet et al. 1989, Gee et al. 2011, Canan et al. 2013). However, literature reviewing the use of cell saver in orthopedic trauma surgery, specifically acetabular surgery is limited. Our institute performed a retrospective review of 63 consecutive operative acetabular fractures at a level one trauma center. Our study revealed that patients with blood loss of less than 400 mL were 13 times less likely to receive autologous blood, and patients with hemoglobin less than 10.5 were 5 times less likely to receive autologous transfusion (p < 0.05). We also found that no patients with a hemoglobin level less than 10.5 and EBL less than 400 mL received autologous blood return. Autologous blood transfusion had no effect on volume or rate of allogenic blood transfusion. We believed that if a patient's preoperative hemoglobin is less than 10.5 or expected blood loss is less than 400 mL, then CS should have a very limited role, if any, in the preoperative blood conservation strategy. We found ASA greater than 2, BMI greater than 24 and associated fracture type to be a risk factor for high blood loss.

Nonlinear analysis of heart rate variability for evaluating the growing pig stress response to an acute heat episode.

Heart rate variability (HRV) is a proxy measure of autonomic function and can be used as an indicator of swine stress. While traditional linear measures are used to distinguish between stressed and unstressed treatments, inclusion of nonlinear HRV measures that evaluate data structure and organization shows promise for improving HRV interpretation. The objective of this study was to evaluate the inclusion of nonlinear HRV measures in response to an acute heat episode. Twenty 12- to 14-week-old growing pigs were individually housed for 7 days and acclimated to thermoneutral conditions (20.35°C ± 0.01°C; 67.6% ± 0.2% RH) before undergoing one of the two treatments: (1) thermoneutral control (TN; n = 10 pigs) or (2) acute heat stress (HS; n = 10 pigs; 32.6°C ± 0.1°C; 26.2% ± 0.1% RH). In Phase 1 of the experimental procedure (P1; 60 min), pigs underwent a baseline HRV measurement period in thermoneutral conditions before treatment [Phase 2; P2; 60 min once gastrointestinal temperature (Tg) reached 40.6°C], where HS pigs were exposed to heated conditions and TN pigs remained in thermoneutral conditions. After P2, all pigs were moved back to thermoneutral conditions (Phase 3; P3; 60 min). During each phase, Tg data were collected every 5 min and behavioural data were collected to evaluate the amount of time each pig spent in an active posture. Additionally, linear (time and frequency domain) and nonlinear [sample entropy (SampEn), de-trended fluctuation analysis, percentage recurrence, percentage determinism (%DET), mean diagonal line length in a recurrence plot] HRV measures were quantified. Heat stressed pigs exhibited greater Tg (P = 0.002) and spent less time in an active posture compared to TN pigs during P2 (P = 0.0003). Additionally, low frequency to high frequency ratio was greater in HS pigs during P3 compared to TN pigs (P = 0.02). SampEn was reduced in HS pigs during P2 (P = 0.01) and P3 (P = 0.03) compared to TN pigs. Heat stressed pigs exhibited greater %DET during P3 (P = 0.03) and tended to have greater %DET (P = 0.09) during P2 than TN pigs. No differences between treatments were detected for the remaining HRV measures. In conclusion, linear HRV measures were largely unchanged during P2. However, changes to SampEn and %DET suggest increased heat stress as a result of the acute heat episode. Future work should continue to evaluate the benefits of including nonlinear HRV measures in HRV analysis of swine heat stress.

Short communication: Assessment of disbudding pain in dairy calves using nonlinear measures of heart rate variability.

The purpose of this study was to evaluate whether pain-related stress caused by disbudding could be detected using nonlinear measures of heart rate variability (HRV). Twenty-five female Holstein calves (4-7 wk of age) were randomly assigned to 1 of 3 treatments: (1) sham disbud (SHAM; n = 9), (2) disbud with lidocaine-meloxicam pain mitigation (MED; n = 8), or (3) disbud without pain mitigation (NoMED; n = 8). Heart rate variability (sample entropy, percentage determinism, percentage recurrence, or mean length of diagonal lines in a recurrence plot) was recorded on d -1, 0, 1, 3, and 5 relative to the experimental procedure, with disbudding taking place on d 0. The short-term detrended fluctuation analysis scaling exponent was greater in MED calves than in SHAM calves, indicating a greater stress response to the disbudding procedure regardless of pain mitigation. These results indicate that calves in the MED group may have experienced pain-related stress as a result of the disbudding procedure. The remaining nonlinear HRV measures did not differ by treatment. Future research on this topic should address additional potential confounding factors, such as the effect of pain-mitigating drugs on autonomic function or the influence of the autonomic nervous system on wound healing, that may prohibit HRV measurement as an indicator of disbudding pain severity.

Determining the effects of early gestation in utero heat stress on postnatal fasting heat production and circulating biomarkers associated with metabolism in growing pigs.

The study objective was to characterize effects of early gestation in utero heat stress (IUHS) on postnatal fasting heat production (FHP) and blood biomarkers associated with metabolism in growing pigs. Based on previous observation of increased postnatal core body temperature set point in IUHS pigs, we hypothesized that FHP would be altered during postnatal life because of IUHS. Pregnant first-parity gilts were exposed to thermoneutral (TN; = 4; 17.8 ± 0.1°C) or heat stress (HS; = 4; cyclical 28 to 38°C) conditions from d 30 to 60 of gestation. At weaning (21 d of age), 2 median-weight male pigs (1 barrow and 1 boar) were selected from each litter ( = 8 in utero TN [IUTN] and 8 IUHS pigs) and then housed in TN conditions based on age. Blood samples were collected at 8, 9, and 10 wk of age when pigs were in a fed state to analyze thyroxine (T4) and triiodothyronine (T3) concentrations. Pigs were trained to enter an indirect calorimeter from wk 8 through 10 of life and then acclimated over a 24-h period 1 wk prior to testing. At 12 wk of age, pigs were fasted for 24 h, and then indirect calorimetry was performed on individual pigs over a 23-h testing period to determine FHP and the respiratory quotient in 3 intervals (0900 to 1700 h, 1700 to 0000 h, and 0000 to 0800 h). Body weight was determined before and after testing and was similar for all pigs ( = 0.77; 37.0 ± 0.5 kg BW). Data were analyzed using PROC MIXED in SAS 9.4. No boar vs. barrow differences were observed with any analysis. Overall, FHP per kilogram BW was greater ( = 0.03; 12.1%) in IUHS pigs compared with IUTN pigs. Fasting heat production per kilogram BW was greater ( < 0.01; 19.8%) from 0900 to 1700 h compared with 1700 to 0000 h and 0000 to 0800 h and was greater (10.9%) from 1700 to 0000 h compared with 0000 to 0800 h. The RQ did not differ by in utero treatment ( = 0.51; 0.72 ± 0.01); however, the RQ was increased ( < 0.01; 13.0%) from 1700 to 0000 h compared with 0900 to 1700 h and 0000 to 0800 h. No other FHP and RQ differences were detected. Although no in utero treatment differences were observed for T4 ( = 0.11; 52.2 ± 6.2 ng/mL), T3 was greater overall ( = 0.04; 19.5%) in IUHS pigs than in IUTN pigs. In summary, FHP and circulating T3 were increased in IUHS pigs, and this may have implications for postnatal production efficiency in pigs gestated during hot summer months.

Evaluating Pekin duck walking ability using a treadmill performance test.

Gait scoring is the most popular method for assessing the walking ability of poultry species. Although inexpensive and easy to implement, gait scoring systems are often criticized for being subjective. Using a treadmill performance test we assessed whether observable differences in Pekin duck walking ability identified using a gait scoring system translated to differences in walking performance. One hundred and eighty ducks were selected using a three-category gait scoring system (GS0 = smooth gait, n = 55; GS0.5 = labored walk without easily identifiable impediment, n = 56; GS1 = obvious impediment, n = 59) and the amount of time each duck was able to sustain walking on a treadmill at a speed of 0.31 m/s was evaluated. The walking test ended when each duck met one of three elimination criteria: (1) The duck walked for a maximum time of ten minutes, (2) the duck required support from the observer's hand for more than three seconds in order to continue walking on the treadmill, or (3) the duck sat down on the treadmill and made no attempt to stand despite receiving assistance from the observer. Data were analyzed in SAS 9.4 using PROC GLM. Tukey's multiple comparison test was used to compare differences in time spent walking between gait scores. Significant differences were found between all gait scores (P < 0.05). Behavioral correlates of walking performance were investigated. Video recorded during the treadmill test was analyzed for counts of sitting, standing, and leaning behaviors. Data were analyzed in SAS 9.4 using a negative binomial model for count data. No differences were found between gait scores for counts of sitting, standing, and leaning behaviors (P > 0.05). In conclusion, the amount of time spent walking on the treadmill corresponded to gait score and was an effective measurement for quantifying Pekin duck walking ability. The test could be a valuable tool for assessing the development of walking issues or the effectiveness of treatments aimed at promoting leg health.

Neurogenesis in the olfactory bulb of adult zebrafish.

Cell genesis in the adult brain of zebrafish, with specific reference to the olfactory bulbs, was examined using bromodeoxyuridine immunocytochemistry. Mature fish were exposed to a 1% solution of the thymidine analog 5-bromo-2'-deoxyuridine for 1 h and then killed after short (4-h) or long (3-4-week) survival periods. A monoclonal antibody to bromodeoxyuridine allowed visualization of cells that incorporated the drug during the S phase of mitosis. Four hours after administration of the drug, antibody-labeled cells were found almost exclusively in the proliferative zones around the ventricles and in the cerebellum. Very few labeled nuclei were seen in other locations in the brain, indicating that cell genesis occurs in discrete regions in adults. The few labeled profiles in the olfactory bulbs were located in the olfactory nerve layer; these profiles had the morphology of glial nuclei and did not stain with a neuronal marker, the Hu antibody. After longer survival times, labeled cells were present throughout the layers of the olfactory bulb, and many of the immunoreactive profiles in the internal cell layer were also labeled with the Hu antibody, indicating that they are likely adult-formed interneurons. Thus, neurogenesis continues in the olfactory bulb of adult zebrafish. Understanding the process of the generation of new neurons in the brain of adult animals can lead to important insights into neural regeneration and adult plasticity.

Induction of butane consumption in Pseudomonas butanovora.

The induction of the enzyme activities involved in butane metabolism in Pseudomonas butanovora was characterized. P. butanovora was grown on butane or its metabolites, both singly and in mixtures with other growth substrates. Cells grown in each of the butane metabolites readily consumed the growth substrate and downstream metabolites, but consumed the upstream butane metabolites more slowly. Upstream activities in the butane metabolism could be induced by downstream metabolites, but to much lower levels than with the primary substrate. The induction of butane oxidation was not repressed when P. butanovora was grown or incubated in a mixture of butane and 1-butanol, butyraldehyde or butyrate. However, no induction of butane consumption was observed in a mixture of butane and lactate, which is indicative of catabolite repression. In lactate-grown cells that were rid of the growth substrate and incubated with butane and acetylene (to inactivate newly formed butane monooxygenase), the consumption of butane, 1-butanol and butyraldehyde consumption was not induced. The overall results suggest an independent regulatory mechanism for each of the enzyme activities in butane metabolism. In addition, a low, constitutive butane oxidation was observed in cells grown on substrates other than butane metabolites.

Advances in device lead extraction.

The removal of chronically implanted pacemaker and defibrillator leads has evolved over the past 20 years into an integral part of the medical and surgical practice of electrophysiology. It is the basis for management of device-related complications. Lead removal has progressed from just pulling, to a sophisticated procedure based on telescoping sheaths, counterpressure, and countertraction. Current telescoping sheaths have a powered tip (laser or electrosurgical) for more efficient extirpation of leads from encapsulating fibrous tissue. The management of a device infection exemplifies the spectrum of procedures ranging from debridement of inflammatory tissue to transvenous, transatrial, or epicardial lead reimplantation (care must be given to the consequences of chronic implant complications such as superior vein occlusion). The magnitude of these lead removal procedures ranges from a transvenous procedure to cardiopulmonary bypass removing a pannus of infected material. Current procedure related mortality is less than 0.2% at experienced centers.

Elliptic flow in Au+Au collisions at square root(S)NN = 130 GeV.

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

Cross-ventricular endless loop tachycardia during biventricular pacing.

This report describes the development of an unusual pacemaker tachycardia in a patient with a conventional dual chamber pacemaker used for biventricular pacing in the VVIR mode. The atrial channel was connected to the left ventricle and the ventricular channel to the right ventricle. The tachycardia was sustained by sensing of the T wave by the "atrial channel" which triggered pacing by the "ventricular channel. " This "cross-ventricular" endless loop tachycardia is a reentrant pacemaker tachycardia like classic endless loop tachycardia and can be prevented by appropriate programming of the pacemaker.

Recommendations for extraction of chronically implanted transvenous pacing and defibrillator leads: indications, facilities, training. North American Society of Pacing and Electrophysiology Lead Extraction Conference Faculty.

The procedure of lead removal has recently matured into a definable, teachable art with its own specific tools and techniques. It is now time to recognize and formalize the practice of lead removal according to the current methods of medicine and the health care industry. In addition, since at this time the only prospective scientific study of lead extraction is the PLEXES trial, we suggest that studies relating to the techniques of and indications for lead extraction be designed. Recommendations for a common set of definitions, for a framework of training and reviewing physicians in the art, for general methods of reimbursement, and for consistency among clinical trials have been made. Implementation of these recommendations will require additional effort and cooperation from practicing physicians, medical societies, hospital administrations, and industry.

Deafferentation-induced changes in the olfactory bulb of adult zebrafish.

The influence of the olfactory organ on maintenance of olfactory bulb structure was examined in zebrafish, using peripheral deafferentation. This fish provides a model in which the olfactory organ is easily accessible for removal, the animals easily survive the surgery, and the olfactory bulbs are small enough to allow rigorous analysis of the resulting effects. Unilateral olfactory organ ablations were performed on anesthetized adult zebrafish using a small-vessel cautery iron. Fish were allowed to survive for 1, 3, or 6 weeks following the procedure. Analysis of deafferented animals revealed that most, if not all, of the olfactory organ was missing on the ablated side, and the structure did not regenerate. The morphology of the olfactory bulb was affected notably by the removal of its primary afferent innervation. The olfactory nerve layer was diminished at 1 week and absent by 3 weeks post-deafferentation. At all of the survival times the deafferented bulb appeared significantly smaller at the gross level, and there was a statistically significant effect on bulb size and cell number after 6 weeks. Tyrosine hydroxylase expression, as revealed by immunohistochemistry, was decreased noticeably on the ablated side. In conclusion, the olfactory organ is important in the preservation of normal olfactory bulb anatomy and neurochemistry in adult zebrafish. Thus, the influence of the periphery does not end with the formation of the mature olfactory bulb.

Laparoscopic colon resections: a five-year retrospective review.

In recent years, laparoscopic surgery has become a matter of growing interest. It has been shown that laparoscopic colectomy is well tolerated and safe for benign disease. However, there is some uncertainty about using this method for malignant disease when curative resection is the aim. These uncertainties mainly consist of spread of cancer to port site, long-term survival, and adequacy of resection. The majority of laparoscopic colectomies are technically assisted procedures in which anastomosis is performed outside the abdomen. However, some surgeons are now performing this surgery totally laparoscopically with the anastomosis performed inside the abdomen. Laparoscopic colectomy is currently practiced with great frequency by general surgeons. Its performance requires a steep learning curve and a large number of cases to obtain proficiency. The indications for laparoscopic colectomy are different from one institution to another. In some institutions all patients with colorectal disease are candidates for laparoscopic colectomy and in others it may be limited to benign disease only. The purpose of this review is to analyze all laparoscopic colectomies performed at our medical center since 1992. We conducted a retrospective chart review of both hospital and clinic charts of patients who underwent colectomies at our hospital. A total of 338 patient charts were reviewed. In a comparison of both laparoscopic (n = 285) and converted (n = 53) methods, the age and operative time were about the same. Age average and operating room time average were similar for both groups. With laparoscopy, there was a 3-day drop in length of hospital stay as well as a 1-day-earlier regaining of bowel function. Hospital cost dropped 5000 dollars average for the laparoscopic colectomy. The conversion rate at our center was 15 per cent. Complication rates were lower in the laparoscopic group. Recurrence of cancer at the port site (0.7%) was no higher than in the converted group (incisional recurrence, 1.8%). We conclude that laparoscopic colectomy does show an improvement in return of bowel function, hospital cost, and shorter hospital stay. Long-term follow-up will be necessary to determine the effectiveness of laparoscopic colon resection for colorectal cancer.

Stat6 signaling promotes protective immunity against Trichinella spiralis through a mast cell- and T cell-dependent mechanism.

Studies in mice infected with the gastrointestinal nematode parasite Nippostrongylus brasiliensis demonstrated that IL-4/IL-13 activation of Stat6 suppresses development of intestinal mastocytosis and does not contribute to IL-4/IL-13 production, but is still essential for parasite expulsion. Because expulsion of another gastrointestinal nematode, Trichinella spiralis, unlike N. brasiliensis expulsion, is mast cell dependent, these observations suggested that T. spiralis expulsion would be Stat6 independent. Instead, we find that Stat6 activation by IL-4/IL-13 is required in T. spiralis-infected mice for the mast cell responses that induce worm expulsion and for the cytokine responses that induce intestinal mastocytosis. Furthermore, although IL-4 induces N. brasiliensis expulsion in the absence of B cells, T cells, and mast cells, mast cells and T cells are required for IL-4 induction of T. spiralis expulsion. Thus, Stat6 signaling is required for host protection against N. brasiliensis and T. spiralis but contributes to expulsion of these two worms by different mechanisms. The induction of multiple effector mechanisms by Stat6 signaling provides a way for a cytokine response induced by most gastrointestinal nematode parasites to protect against most of these parasites, even though different effector mechanisms are required for protection against different nematodes.

Cardiac lead extraction with a novel locking stylet.

Extraction of chronically implanted pacing and defibrillator leads is facilitated by using specialized locking stylets placed in the lead to allow application of traction and to stabilize the lead during sheath dissection of fibrotic tissue. We report the initial multicenter series of cases using a novel lead locking device (LLD). In 57 consecutive patients presenting at 6 institutions for lead extraction, 99 leads were treated using the LLD. After removing the pulse generator, leads were severed, the inner coil dilated and an LLD was successfully inserted and locked in the inner lumen of 95/99 (96 %) leads. With traction applied to the LLD, a variety of sheaths were advanced over the lead body to separate it from adhesions. In 97/99 (98 %) leads, all or most of the lead was removed via the implant vein; 2 leads were removed via the femoral vein. No major complications were observed. The LLD deploys safely and reliably, and provides stable support for advancement of dissecting sheaths.

IL-13-mediated worm expulsion is B7 independent and IFN-gamma sensitive.

B7 costimulation is a required component of many type 2 immune responses, including allergy and protective immunity to many nematode parasites. This response includes elevations in Th2 cytokines and associated effector functions including elevations in serum IgG1 and IgE and parasite expulsion. In studies of mice infected with Trichuris muris, blocking B7 ligand interactions inhibited protective immunity, suppressed IL-4 production, and enhanced IFN-gamma production, but unexpectedly did not inhibit production of the Th2 cytokine, IL-13. Blocking both IFN-gamma and B7 restored protective immunity, which was IL-13 dependent, but did not restore IL-4 or associated IgE responses. Although IL-13 was required for worm expulsion in mice in which both IFN-gamma and B7 were blocked, IL-4 could mediate expulsion in the absence of both IL-13 and IFN-gamma. These studies demonstrate that 1) B7 costimulation is required to induce IL-4, but not IL-13 responses; 2) IL-13 is elevated in association with the IFN-gamma response that occurs following inhibition of B7 interactions, but can only mediate IL-4-independent protection when IFN-gamma is also inhibited; and 3) increased IL-13 production, in the absence of increased IL-4 production, is not associated with an IgE response, even in the absence of IFN-gamma.

Intravascular extraction of problematic or infected permanent pacemaker leads: 1994-1996. U.S. Extraction Database, MED Institute.

Of the 400,000-500,000 permanent pacemaker leads implanted worldwide each year, around 10% may eventually fail or become infected, becoming potential candidates for removal. Intravascular techniques for removing problematic or infected leads evolved over a 5-year period (1989-1993). This article analyzes results from January 1994 through April 1996, a period during which techniques were fairly stable. Extraction of 3,540 leads from 2,338 patients was attempted at 226 centers. Indications were: infection (27%), nonfunctional or incompatible leads (25%), Accufix or Encore leads (46%), or other causes (2%). Patients were 64+/-17 years of age (range 5-96); 59% were men, 41% women. Leads were implanted 47+/-41 months (maximum 26 years), in the atrium (53%), ventricle (46%), or SVC (1%). Extraction was attempted via the implant vein using locking stylets and dilator sheaths, and/or transfemorally using snares, retrieval baskets, and sheaths. Complete removal was achieved for 93% of leads, partial for 5%, and 2% were not removed. Risk of incomplete or failed extraction increased with implant duration (P<0.0001), less experienced physicians (P<0.0001), ventricular leads (P<0.005), noninfected patients (P<0.0005), and younger patients (P<0.0001). Major complications were reported for 1.4% of patients (<1% at centers with >300 cases), minor for 1.7%. Risk of complications increased with number of leads removed (P<0.005) and with less experienced physicians (P<0.005); risk of major complications was higher for women (P<0.01). Given physician experience, appropriate precautions, and appropriate patient selection, contemporary lead removal techniques allow success with low complication rates.