Intensive care unit admission parameters improve the accuracy of operative mortality predictive models in cardiac surgery

Background

Operative mortality risk in cardiac surgery is usually assessed using preoperative risk models. However, intraoperative factors may change the risk profile of the patients, and parameters at the admission in the intensive care unit may be relevant in determining the operative mortality. This study investigates the association between a number of parameters at the admission in the intensive care unit and the operative mortality, and verifies the hypothesis that including these parameters into the preoperative risk models may increase the accuracy of prediction of the operative mortality.

Methodology

929 adult patients who underwent cardiac surgery were admitted to the study. The preoperative risk profile was assessed using the logistic EuroSCORE and the ACEF score. A number of parameters recorded at the admission in the intensive care unit were explored for univariate and multivariable association with the operative mortality.

Principal Findings

A heart rate higher than 120 beats per minute and a blood lactate value higher than 4 mmol/L at the admission in the intensive care unit were independent predictors of operative mortality, with odds ratio of 6.7 and 13.4 respectively. Including these parameters into the logistic EuroSCORE and the ACEF score increased their accuracy (area under the curve 0.85 to 0.88 for the logistic EuroSCORE and 0.81 to 0.86 for the ACEF score).

Conclusions

A double-stage assessment of operative mortality risk provides a higher accuracy of the prediction. Elevated blood lactates and tachycardia reflect a condition of inadequate cardiac output. Their inclusion in the assessment of the severity of the clinical conditions after cardiac surgery may offer a useful tool to introduce more sophisticated hemodynamic monitoring techniques. Comparison between the predicted operative mortality risk before and after the operation may offer an assessment of the operative performance.     

Use of operative temperature and standard operative temperature models in thermal biology

Operative temperature (T_e) and standard operative temperature (T_es) models have been used to address ecological questions about the thermal biology of ectotherms and endotherms for over 25 years. This review focuses on the accuracy and use of T_e and T_es models in ecological and physiological studies. The utility of T_e and T_es models lie in the fact that they take a multivariate problem involving inputs of air temperature, ground temperature, solar radiation, and wind speed and map them into a single thermal metric on a spatial scale appropriate for the animal. The most reliable T_e models are copper casts that mimic the morphology and absorptivity of an animal. Simplified T_e models such as cylinders and spheres have been shown to produce errors in T_e as large as 12 °C under certain conditions and should only be used after careful calibration against a live animal. The accuracy of heated T_es models has been addressed in much less detail then that of T_e models. When calibrated and used under conditions of low solar radiation, heated taxidermic mounts and simplified T_es models produce errors in net heat production on the order of 5% or less. In order to provide reliable data, all types of models must be calibrated over an ecologically realistic range of environmental conditions experienced by the animal. This advice has been largely ignored in the literature, where 61% of the of studies examined failed to properly calibrate the models prior to use. Additionally, studies using these models tend to lack experimental rigor, using only one or two models to make measurements on 1 or 2 days of the active season. When used correctly, T_e and T_es models can be powerful tools for integrating the thermal environment experienced by an animal into a single metric that can address questions regarding the ecology, physiology, and behavior of endotherms and ectotherms. However, until investigators make the effort to use these models in a scientifically valid manner with proper calibration and experimental design their value to thermal biologists will be limited.     

Modified operative technique for involutional lower lid entropion

The paper presents a modified operative technique for involutional lower lid entropion. The prospective noncomparative study of 101 lower eyelids of 88 patients undergoing surgery for involutional lower lid entropion was conducted in period from September 2005 until March 2012. Indication for the surgery was entropion, previously untreated, with moderate to severe horizontal lid laxity and no clinically relevant medial and lateral canthal tendon laxity. The operative technique is our modification of Quickert and Jones procedures. Photo was taken preoperatively and one month after surgery. Clinical follow-up was at 7th postoperative day, one month and six months after surgery and in case of the recurrence. Long-term follow-up was obtained via telephone interviews. There were 44 male (50%) and 44 female (50%) patients included in the study. The age of patients was in average 73.27 +/- 8.1 years (range 53-90 years). Early postoperative complication was localized lid swelling found in two patients starting 4-6 weeks postoperatively at the area of absorbable suture. It resolved spontaneously in two and three weeks respectively. There was recurrence of entropion in 11 eyelids (10.89%) of 10 patients. The mean interval between primary surgery and the recurrence was 17.45 +/- 14.84 months (range 4-48 months). In these eyelids Jones procedure was performed. However in four eyelids of four patients from the recurrent group an additional surgery needed to be performed after 6, 12, 12 and 17 months respectively. Our modification of surgical treatment for involutional lower lid entropion was effective in 89.11% of eyelids. Complications of the procedure were scarce.     

Quadrilateral space syndrome: diagnosis and operative decompression technique

We present a series of five patients with quadrilateral space syndrome. All patients had the diagnosis made on the basis of (1) tenderness over the quadrilateral space, (2) paresthesia over the lateral shoulder and upper posterior arm, and (3) deltoid weakness associated with decreased shoulder abduction. A history of trauma was present in each patient. The operative technique described utilizes a cosmetically acceptable incision and is without the need to divide the deltoid from its origin on the scapular spine. The technique minimizes postoperative bleeding and facilities rehabilitation. Arteriography of the posterior circumflex humeral artery was not found necessary to make the diagnosis of axillary nerve entrapment in the quadrilateral space.     

Snakebite mortality in India: a nationally representative mortality survey

Background

India has long been thought to have more snakebites than any other country. However, inadequate hospital-based reporting has resulted in estimates of total annual snakebite mortality ranging widely from about 1,300 to 50,000. We calculated direct estimates of snakebite mortality from a national mortality survey.

Methods and Findings

We conducted a nationally representative study of 123,000 deaths from 6,671 randomly selected areas in 2001–03. Full-time, non-medical field workers interviewed living respondents about all deaths. The underlying causes were independently coded by two of 130 trained physicians. Discrepancies were resolved by anonymous reconciliation or, failing that, by adjudication.A total of 562 deaths (0.47% of total deaths) were assigned to snakebites. Snakebite deaths occurred mostly in rural areas (97%), were more common in males (59%) than females (41%), and peaked at ages 15–29 years (25%) and during the monsoon months of June to September. This proportion represents about 45,900 annual snakebite deaths nationally (99% CI 40,900 to 50,900) or an annual age-standardised rate of 4.1/100,000 (99% CI 3.6–4.5), with higher rates in rural areas (5.4/100,000; 99% CI 4.8–6.0), and with the highest state rate in Andhra Pradesh (6.2). Annual snakebite deaths were greatest in the states of Uttar Pradesh (8,700), Andhra Pradesh (5,200), and Bihar (4,500).

Conclusions

Snakebite remains an underestimated cause of accidental death in modern India. Because a large proportion of global totals of snakebites arise from India, global snakebite totals might also be underestimated. Community education, appropriate training of medical staff and better distribution of antivenom, especially to the 13 states with the highest prevalence, could reduce snakebite deaths in India.     

Physically modeling operative temperatures and evaporation rates in amphibians

• (1)We designed a physical model that simulates the thermal and evaporative properties of live Western toads (Bufo boreas).
• (2)In controlled tests, the model tracked the body temperature of live toads with an average error of 0.3±0.03 °C (test range=4–30 °C).
• (3)It estimated the evaporative water loss of live toads with an average error of 0.35–0.65  g/h, or about 14% (test range=0.7–9 g/h).
• (4)Data collected with this physical model should provide an effective way for biologists to better understand habitat selection in toads and other amphibians

     

Respiratory tract mortality in cement workers: a proportionate mortality study

Background

The evidence regarding the association between lung cancer and occupational exposure to cement is controversial. This study investigated causes of deaths from cancer of respiratory tract among cement workers.

Methods

The deaths of the Greek Cement Workers Compensation Scheme were analyzed covering the period 1969-1998. All respiratory, lung, laryngeal and urinary bladder cancer proportionate mortality were calculated for cement production, maintenance, and office workers in the cement industry. Mortality from urinary bladder cancer was used as an indirect indicator of the confounding effect of smoking.

Results

Mortality from all respiratory cancer was significantly increased in cement production workers (PMR?=?1.91; 95% CI 1.54 to 2.33). The proportionate mortality from lung cancer was significantly elevated (PMR?=?2.05; 95% CI 1.65 to 2.52). A statistically significant increase in proportionate mortality due to respiratory (PMR?=?1.7; 95% CI 1.2 to 2.34). and lung cancer (PMR?=?1.67;95% CI?=?1.15-2.34) among maintenance workers has been observed. The PMR among the three groups of workers (production, maintenance, office) did differ significantly for lung cancer (p?=?0.001), while the PMR for urinary bladder cancer found to be similar among the three groups of cement workers.

Conclusion

Cement production, and maintenance workers presented increased lung and respiratory cancer proportionate mortality, and this finding probably cannot be explained by the confounding effect of smoking alone. Further research including use of prospective cohort studies is needed in order to establish a causal association between occupational exposure to cement and risk of lung cancer.     

BCG vaccination and cancer mortality

Summary The mortality rate from leukemia and other neoplastic diseases for the years 1957–1969 was compared in 85,356 BCG-vaccinated newborns at Cook County Hospital, Chicago, and 534,870 nonvaccinated population in Chicago (all black). All cases of cancer deaths under 20 years of age in the black population of Chicago were obtained from death certificates at the Chicago Board of Health. The total black population 20 years of age and under was determined by demographic means from the Chicago Board of Health birth records, adjusted for deaths under the period of study. There were 13 deaths among the vaccinated for a rate of 1.17/100,000/year and 306 deaths among the nonvaccinated for a rate of 4.39/100,000/year. The difference was statistically highly significant (p<0.001). This was a reduction of 74% in the vaccinated group as compared to the nonvaccinated. There were no deaths from malignancies in the under 1 year of age group in the vaccinated, but a drop in the rates to 50% or less in the later age groups (except 10–14 years) in the vaccinated as compared to the nonvaccinated. Thus revaccination at given intervals (1–2 years) is recommended. The National Cancer Institute checked death reports due to cancer elsewhere in the country in our vaccinated population. To reduce the possibility of error, deaths due to trauma in the two groups were determined. No differences in the rates were found. The major categories of neoplasms for this age group were (1) leukemia, (2) central nervous system, (3) lymphoma, and (4) bone and connective tissue. This was a retrospective study. Statistically designed, controlled studies may provide definite conclusions.     

Cancer mortality in metal workers.

Age-standardized proportional mortality ratios (PMRs) were calculated for 10 036 metal workers in British Columbia with the use of information on cause of death and occupation recorded in death registrations from 1950 to 1978. Metal workers were found to have a significantly increased risk of death from lung cancer (PMR = 134). In addition, certain occupational groups of metal workers were found, for the first time, to be at increased risk of death from other types of cancer; these included leukemia (PMR = 356) and cancer of the rectum (PMR = 248) in metal mill workers, Hodgkin''s disease in welders (PMR = 242) and multiple myeloma in machinists (PMR = 209).     

Performance and mortality of farmed hares

Performance and mortality of hares were evaluated for 2 consecutive years in a large farm in Veneto Region (Northern Italy). On average, fertile reproductive pairs (n=318) gave birth 4.8 times and produced 11.4 live leverets, weaned 8.4 leverets and produced 7.0 growing hares (60 days) every year. Mean mortality was 3.6%, 22.9%, 9.7% and 2.5% in newborn (0 to 2 days of age), suckling (3 to 25 days), growing (26 to 60 days) and sub-adult (61 days until sale) hares, respectively. The main causes of mortality were enteric diseases (75.5%, 75.9% and 12.1% in suckling, growing and sub-adult hares, respectively), followed by respiratory diseases (3.4%, 8.0% and 36.2% in suckling, growing and sub-adult hares, respectively), starvation (11.3% and 8.8% in suckling and growing hares, respectively) and trauma (7.1%, 2.3% and 30.2% in suckling, growing and sub-adult hares, respectively). In reproducing hares, mortality was 24.7% and 15.4% in 2010 and 2011, respectively. Respiratory diseases (34.8%) and ulcerative pododermatitis (18.9%) were the most common pathological changes detected in reproducing hares. Farmed hares seem to be affected by diseases resembling those of rabbits reared under intensive conditions. It seems necessary to improve the husbandry of hares to reach satisfactory technical standards and to preserve their health.     

Substrate recognition of nitrogenase-like dark operative protochlorophyllide oxidoreductase from Prochlorococcus marinus

Chlorophyll and bacteriochlorophyll biosynthesis requires the two-electron reduction of protochlorophyllide a ringDbya protochlorophyllide oxidoreductase to form chlorophyllide a. A light-dependent (light-dependent Pchlide oxidoreductase (LPOR)) and an unrelated dark operative enzyme (dark operative Pchlide oxidoreductase (DPOR)) are known. DPOR plays an important role in chlorophyll biosynthesis of gymnosperms, mosses, ferns, algae, and photosynthetic bacteria in the absence of light. Although DPOR shares significant amino acid sequence homologies with nitrogenase, only the initial catalytic steps resemble nitrogenase catalysis. Substrate coordination and subsequent [Fe-S] cluster-dependent catalysis were proposed to be unrelated. Here we characterized the first cyanobacterial DPOR consisting of the homodimeric protein complex ChlL(2) and a heterotetrameric protein complex (ChlNB)(2). The ChlL(2) dimer contains one EPR active [4Fe-4S] cluster, whereas the (ChlNB)(2) complex exhibited EPR signals for two [4Fe-4S] clusters with differences in their g values and temperature-dependent relaxation behavior. These findings indicate variations in the geometry of the individual [4Fe-4S] clusters found in (ChlNB)(2). For the analysis of DPOR substrate recognition, 11 synthetic derivatives with altered substituents on the four pyrrole rings and the isocyclic ring plus eight chlorophyll biosynthetic intermediates were tested as DPOR substrates. Although DPOR tolerated minor modifications of the ring substituents on rings A-C, the catalytic target ring D was apparently found to be coordinated with high specificity. Furthermore, protochlorophyllide a, the corresponding [8-vinyl]-derivative and protochlorophyllide b were equally utilized as substrates. Distinct differences from substrate binding by LPOR were observed. Alternative biosynthetic routes for cyanobacterial chlorophyll biosynthesis with regard to the reduction of the C8-vinyl group and the interconversion of a chlorophyll a/b type C7 methyl/formyl group were deduced.     

Perinatal mortality in triplet births in Japan: time trends and factors influencing mortality.

Perinatal mortality rates (PMRs) in triplets were analyzed using Japanese Vital Statistics during the period of 1980-1998. The total number of perinatal deaths in triplets was 1051. The PMR significantly decreased from 214 per 1000 births in 1980 to 39 in 1998, a reduction of 82%. PMRs in triplets were 11.1-fold higher in 1980 and 6.9-fold higher in 1998 than in singletons, indicating that PMRs improved more in triplets than in singletons during the last two decades in Japan. The PMR was the highest in the third-born, followed by the second- and the first-born triplets in each period. As for maternal age, the PMR was 1.5-3.7 times higher in the < 25 years of age group than the other age groups. Additionally, the PMR was the lowest for birthweight (BW) >or= 2000 g during the entire period. In addition, the PMR decreased with gestational age (GA) of up to 38-39 weeks and increased thereafter. The effects of BW on the PMR were stronger than the effects of GA. The proportion of perinatal deaths in triplets with extremely low BW (< 1000 g) was 74% in 1980-1989 and increased to 82% in 1990-1998. The declining PMR was unlikely to be due to the improvement in BW in triplets. It is likely that it was related to the improved medical management of triplets during the perinatal period and the first week of life. Information obtained in the present study may be useful in counseling pregnant woman about triplet births.     

Review of operative considerations in spinal cord stem cell therapy

Spinal cord injury (SCI) can permanently impair motor and sensory function and has a devastating cost to patients and the United States healthcare system. Stem cell transplantation for treatment of SCI is a new technique aimed at creating biological functional recovery. Operative techniques in stem cell transplantation for SCI are varied. We review various clinical treatment paradigms, surgical techniques and technical considerations important in SCI treatment. The NCBI PubMed database was queried for “SCI” and “stem cell” with a filter placed for “clinical trials”. Thirty-nine articles resulted from the search and 29 were included and evaluated by study authors. A total of 10 articles were excluded (9 not SCI focused or transplantation focused, 1 canine model). Key considerations for stem cell transplantation include method of delivery (intravenous, intrathecal, intramedullary, or excision and engraftment), time course of treatment, number of treatments and time from injury until treatment. There are no phase III clinical trials yet, but decreased time from injury to treatment and a greater number of stem cell injections both seem to increase the chance of functional recovery.     

Factors associated with neonatal lamb mortality

Three factors were associated with lamb neonatal mortality: birthweight (P<0.003), number of lambs born per ewe (P<0.001) and lamb sex (P<0.32). Lamb birthweight had the greatest predictive power for survival during the neonatal period. The neonatal mortality rate was 14.3%. The age specific mortality for lambs one day old was 7.9% (P<0.05). Seventy-nine percent of the lambs that died, did so by the end of the fourth post-natal day. Starvation was associated with 58.3% (P < 0.05) of the lamb deaths.     

Causes of mortality of free-ranging Florida panthers

The Florida panther (Puma concolor coryi) is one of the most endangered mammals, with the entire population estimated to consist of only 30-50 adult animals. Between 1978 and 1999, 73 free-ranging Florida panther carcasses were submitted for postmortem evaluation, of which 47 (64%) were radiocollared and 26 (36%) were uncollared cats. Overall, mortality of panthers > 6-mo-old was due to vehicular trauma in 25 (35%), intraspecific aggression in 19 (26%), illegal kill in seven (10%), research activities in two (3%), infectious diseases in two (3%), esophageal tear in one (1%), pleuritis in one (1%), pyothorax in one (1%), aortic aneurysm in one (1%), atrial septal defect in one (1%), and causes of death were undetermined in 13 (18%) due to autolysis. Of the 25 panthers that were killed by vehicular trauma, 20 (80%) died between October and April. This coincides with increased number of winter visitors to south Florida. Among radiocollared panthers, intraspecific aggression was the primary cause of mortality for 19 (41%) dead cats. Of these cats, 16 (84%) were males and 14 (88%) were either less than 3 or more than 8-yr-old. These animals were probably fighting to establish or retain territory. Among the 26 uncollared panthers, vehicular trauma was the primary cause of mortality and was responsible for 16 (62%) deaths. This study documents the causes of mortality and the age, sex, and seasonal mortality trends for both radiocollared and uncollared free-ranging endangered Florida panthers over a 21-yr-period.     

Classification of perinatal mortality

A classification based upon pathophysiological mechanisms has been applied to perinatal mortality. The approximate relevance of each group was: fetal insufficiency 40%, respiratory failure 30%, developmental abnormality 20%, and the specific mechanisms 10%. Secondary subclassification of each category according to the maturity of the gestation emphasizes the importance of prematurity in the total perinatal mortality (66%) and the relevance of each pathophysiological mechanism in each phase of maturity. The principal mechanism in the mature group is fetal insufficiency and in the premature group, particularly between 20 and 28 weeks, it is neonatal respiratory failure. Perinatal death due to developmental abnormalities occurs most frequently in the mature infant and due to specific mechanisms in the premature infant, particularly between 29 and 36 weeks. It is suggested that greater emphasis should be placed on perinatal mortality rather than the separate consideration of stillbirth and neonatal mortality.     

Causes of mortality of the Wyoming toad

Wyoming toads (Bufo baxteri) that died from January 1989 to June 1996 were submitted to the Wyoming State Veterinary Laboratory (Laramie, Wyoming, USA) for postmortem evaluation. These consisted of 108 free-ranging toads and 170 animals from six captive populations. Ninety-seven (90%) of 108 free-ranging toad carcasses were submitted during September and October. From 1989 to 1992, 27 (77%) of 35 mortalities in the captive populations occurred in October, November, and December. From 1993 to 1996, mortality in captive toads occurred without a seasonal pattern and coincided with changes in hibernation protocols that no longer mimicked natural cycles. Cause of mortality was determined in 147 (53%) of the 278 cases. Mycotic dermatitis with secondary bacterial septicemia was the most frequent diagnosis in 104 (71%) of 147 toads. Basidiobolus ranarum was found by microscopic examination of skin sections in 100 (96%) of 104 of these mortalities. This fungus was isolated from 30 (56%) of 54 free-ranging and 24 (48%) of 50 captive toads. This research documents the causes of mortality for both free-ranging and captive endangered Wyoming toads over a 7 yr period.     

The Scottish perinatal mortality survey.

Perinatal deaths in single births that occurred in Scotland during 1977 were investigated by case-record analysis. Causes of death were divided into nine categories, an extended version of the Aberdeen classification being used. Out of 1012 single perinatal deaths, 265 were due to fetal abnormality, which in 140 cases was malformation of the central nervous system. Of the 747 normally formed infants, 446 weighed 1500 g or more, of whom 82 died intra partum and 154 were born alive. The largest single cause of death was low birth weight in normally formed babies whose mothers had no complications of pregnancy (302 cases). Of these babies, 103 (34%) were growth-retarded. Rhesus incompatibility (16 deaths) and maternal diabetes (seven deaths) were not major causes of perinatal loss. These results were thought to be valuable in illustrating the main causes of perinatal mortality and directing attention to important issues. Hence a modified version of the study is being continued to see whether yearly audit by regional assessors is a feasible and practical way of monitoring trends in perinatal mortality.