Predicting 30-day mortality after hip fracture surgery: Evaluation of the National Hip Fracture Database case-mix adjustment model.

OBJECTIVES: The National Hip Fracture Database (NHFD) publishes hospital-level risk-adjusted mortality rates following hip fracture surgery in England, Wales and Northern Ireland. The performance of the risk model used by the NHFD was compared with the widely-used Nottingham Hip Fracture Score. METHODS: Data from 94 hospitals on patients aged 60 to 110 who had hip fracture surgery between May 2013 and July 2013 were analysed. Data were linked to the Office for National Statistics (ONS) death register to calculate the 30-day mortality rate. Risk of death was predicted for each patient using the NHFD and Nottingham models in a development dataset using logistic regression to define the models' coefficients. This was followed by testing the performance of these refined models in a second validation dataset. RESULTS: The 30-day mortality rate was 5.36% in the validation dataset (n = 3861), slightly lower than the 6.40% in the development dataset (n = 4044). The NHFD and Nottingham models showed a slightly lower discrimination in the validation dataset compared with the development dataset, but both still displayed moderate discriminative power (c-statistic for NHFD = 0.71, 95% confidence interval (CI) 0.67 to 0.74; Nottingham model = 0.70, 95% CI 0.68 to 0.75). Both models defined similar ranges of predicted mortality risk (1% to 18%) in assessment of calibration. CONCLUSIONS: Both models have limitations in predicting mortality for individual patients after hip fracture surgery, but the NHFD risk adjustment model performed as well as the widely-used Nottingham prognostic tool and is therefore a reasonable alternative for risk adjustment in the United Kingdom hip fracture population.Cite this article: Bone Joint Res 2017;6:550-556.

Understanding mortality rates after hip fracture repair using ASA physical status in the National Hip Fracture Database.

Hip fracture is the most common reason for older patients to need emergency anaesthesia and surgery. Up to one-third of patients die in the year after hip fracture, but this view of outcome may encourage therapeutic nihilism in peri-operative decisions and discussions. We used a multicentre national dataset to examine relative and absolute mortality rates for patients presenting with hip fracture, stratified by ASA physical status. We analysed ASA physical status, dates of surgery, death and hospital discharge for 59,369 out of 64,864 patients in the 2015 National Hip Fracture Database; 3914 (6.6%) of whom died in hospital. Rates of death in hospital were 1.8% in ASA 1-2 patients compared with 16.5% in ASA 4 patients. Survival rates for ASA 4 patients on each of the first three postoperative days were: 98.8%, 99.1% and 99.1% (compared with figures of > 99.9% in ASA 1-2 patients over these days). Survival on postoperative day 6 was 99.4% for ASA 4 patients. Nearly half (48.6%) of the 1427 patients who did not have surgery died in hospital. Although technically sound, a focus on cumulative and relative risk of mortality may frame discussions in an unduly negative fashion, discouraging surgeons and anaesthetists from offering an operation, and deterring patients and their loved ones from agreeing to it. A more optimistic and pragmatic explanation that over 98% of ASA 4 patients survive both the day of surgery and the day after it, may be more appropriate.

Secondary analysis of outcomes after 11,085 hip fracture operations from the prospective UK Anaesthesia Sprint Audit of Practice (ASAP-2).

We re-analysed prospective data collected by anaesthetists in the Anaesthesia Sprint Audit of Practice (ASAP-1) to describe associations with linked outcome data. Mortality was 165/11,085 (1.5%) 5 days and 563/11,085 (5.1%) 30 days after surgery and was not associated with anaesthetic technique (general vs. spinal, with or without peripheral nerve blockade). The risk of death increased as blood pressure fell: the odds ratio (95% CI) for mortality within five days after surgery was 0.983 (0.973-0.994) for each 5 mmHg intra-operative increment in systolic blood pressure, p = 0.0016, and 0.980 (0.967-0.993) for each mmHg increment in mean pressure, p = 0.0039. The equivalent odds ratios (95% CI) for 30-day mortality were 0.968 (0.951-0.985), p = 0.0003 and 0.976 (0.964-0.988), p = 0.0001, respectively. The lowest systolic blood pressure after intrathecal local anaesthetic relative to before induction was weakly correlated with a higher volume of subarachnoid bupivacaine: r(2) -0.10 and -0.16 for hyperbaric and isobaric bupivacaine, respectively. A mean 20% relative fall in systolic blood pressure correlated with an administered volume of 1.44 ml hyperbaric bupivacaine. Future research should focus on refining standardised anaesthesia towards administering lower doses of spinal (and general) anaesthesia and maintaining normotension.

Sorption of atrazine on conventional and surface modified activated carbons.

The sorption of atrazine from water has been studied using a conventional activated carbon, F400, an annealed carbon sample, F400AN, and an aminated carbon sample, F400NH(2). Characterisation of the carbon samples showed that sample F400NH(2) had the highest proportion of micropores, but had the lowest values of point of zero charge (PZC) and iso-electric point (IEP). This was attributed to the existence of a high proportion of oxygen containing functional groups. Sorption data showed that sample F400AN was superior in the sorption of atrazine to samples F400 and F400NH(2). It was noted that pore size distribution alone was not the only contributing factor for the uptake of atrazine onto the activated carbons. The sorption data were fitted well using the Freundlich isotherm. The free energy change showed that sorption of atrazine on activated carbons is a spontaneous process. A pseudo-second order kinetic model was used for analysing the kinetic data, and it was concluded that adsorption of atrazine was controlled by a film diffusion mechanism.

Effect of surface modification of an engineered activated carbon on the sorption of 2,4-dichlorophenoxy acetic acid and benazolin from water.

The performance of a conventional (F400) and a surface modified activated carbon (F400AN) has been investigated for the sorption of benazolin and 2,4-dichlorophenoxy acetic acid (2,4-D) from water. It was observed that the modified carbon, F400AN, which was obtained by annealing the conventional sample had a higher BET surface area (960 m2 g(-1) compared to 790 m2 g(-1)) and it had a higher proportion of micropores. This was attributed to the loss of oxygen containing functional groups during the thermal treatment. Zeta potential and pH titration measurements also showed that acidic functionality had been lost on the F400AN sample. The adsorption data were analysed and were fitted well using the Langmuir isotherm. The modified carbon marginally out-performed the conventional activated carbon for sorption of these two herbicides. Thermodynamic parameters (DeltaG0, DeltaH0, and DeltaS0) were determined and their values indicated that the sorption process was spontaneous and endothermic for both herbicides. A pseudo-second-order kinetic model was employed for analysing the kinetic data. It was concluded that the herbicide sorption process was controlled by a film diffusion mechanism.

Investigation of the efficiency of existing air pollution monitoring sites in the state of Kuwait.

The use of mathematical modelling for investigation of the efficiency of existing monitoring sites for the impact of SO(2) emissions from power stations in the state of Kuwait is described. The Industrial Source Complex Short Term (ISCST3) model is utilised to obtain the spatial and temporal variations of SO(2) over residential areas. Statistical comparison between the 50 highest daily measured and predicted SO(2) concentrations at six monitoring sites shows that the model is capable of generating results with accuracy of 60--94%. An important conclusion of this work is that the existing locations of the Kuwait-EPA monitoring stations are not suitable for measuring the actual impact of SO(2). Therefore, there is a need for relocation of these sites to register the highest levels of SO(2) emitted from the current power stations in the state of Kuwait.

Reduced vasorelaxant effect of carbon monoxide in diabetes and the underlying mechanisms.

Carbon monoxide (CO) is an endogenous gaseous factor that relaxes vascular tissues by acting on both the cGMP pathway and calcium-activated K+ (K(Ca)) channels. Whether the vascular effect of CO is altered in diabetes had been unknown. It was found that the CO-induced relaxation of tail artery tissues from streptozotocin-induced diabetic rats was significantly decreased as compared with that of nondiabetic control rats. The blockade of the cGMP pathway with ODQ (1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one) completely abolished the CO-induced relaxation of diabetic tissues but only partially inhibited the CO effect in normal tissues. Single-channel conductance of K(Ca) channels in diabetic smooth muscle cells (SMCs) was not different from that of normal SMCs. However, the sensitivity of K(Ca) channels to CO in diabetic SMCs was significantly reduced. CO (10 micromol/l) induced an 81 +/- 24% increase in the mean open probability of single K(Ca) channels in normal SMCs but had no effect in diabetic SMCs. Longterm culture of normal vascular SMCs with 25 mmol/l glucose or 25 mmol/l 3-OMG (3-O-methylglucose) but not 25 mmol/l mannitol significantly reduced the sensitivity of K(Ca) channels to CO. On the other hand, the sensitivity of K(Ca) channels to CO was regained in diabetic SMCs that were cultured with 5 mmol/l glucose for a prolonged period. The decreased vasorelaxant effect of CO in diabetes represents a novel mechanism for the vascular complications of diabetes, which could be closely related to the glycation of K(Ca) channels in diabetic vascular SMCs.

Inoculum Densities of Fusarium oxysporum f. sp. vasinfectum and Meloidogyne incognita in Relation to the Development of Fusarium Wilt and the Phenology of Cotton Plants (Gossypium hirsutum).

ABSTRACT Development of Fusarium wilt in upland cotton (Gossypium hirsutum) usually requires infections of plants by both Meloidogyne incognita and Fusarium oxysporum f. sp. vasinfectum. In this study, the soil densities of M. incognita and F. oxysporum f. sp. vasinfectum and the incidence of Fusarium wilt in three field sites were determined in 1982-1984. Multiple regression analysis of percent incidence of Fusarium wilt symptoms on population densities of M. incognita and F. oxysporum f. sp. vasinfectum yielded a significant fit (R (2) = 0.64) only on F. oxysporum f. sp. vasinfectum. Significant t-values for slope were also obtained for the interaction of M. incognita and F. oxysporum f. sp. vasinfectum, but densities of M. incognita and F. oxysporum f. sp. vasinfectum were also related on a log(10) scale. The physiological time of appearance of first foliar symptoms of Fusarium wilt, based on a degree-days threshold of 11.9 degrees C (53.5 degrees F), was used as a basis for determining disease progress curves and the phenology of cotton plant growth and development. Effects of Fusarium wilt on plant height and boll set were determined in three successive years. Increases in both of these plant characteristics decreased or stopped before foliar symptoms were apparent. Seed cotton yields of plant cohorts that developed foliar wilt symptoms early in the season (before 2,000 F degree-days) were variable but not much different in these years. This contrasted with cohorts of plants that first showed foliar symptoms late in the season (after 2,400 F degree-days) and cohorts of plants that showed no foliar symptoms of wilt. Regression analyses for 1982-1984 indicated moderate to weak correlations (r = 0.16-0.74) of the time of appearance of the first foliar symptoms and seed cotton yields.

Effects of Verticillium dahliae Infection of Cotton Plants (Gossypium hirsutum) on Potassium Levels in Leaf Petioles.

Two isolates of Verticillium dahliae, a black microsclerotial isolate and an isolate from potassium deficient cotton plants that forms white colonies on agar media, were examined for their effects on the potassium content of cotton plants. The potassium content of petioles from fully expanded leaves collected at random from branches 6 to 7 nodes below the terminal node were monitored during July and August in 1993 to 1995. Potassium contents of petioles from plants inoculated with V. dahliae did not differ significantly from plants injected with sterile water until the plants were nearing peak boll load. Both isolates caused a gradual development of potassium deficiency symptoms in leaves of inoculated plants and a decrease in petiole potassium, often accompanied by chlorosis and necrosis typical of Verticillium wilt. These results suggest that infection of cotton plants by V. dahliae causes an impairment in the uptake and translocation of potassium that is often associated with the development of potassium deficiency symptoms in leaves of plants with large boll loads.

Radiation exposure of orthopaedic trainees: quantifying the risk.

Interest in radiation protection issues has recently grown within the medical profession. Several investigators have examined the radiation exposure of orthopaedic surgeons using X-rays during trauma surgery, and found that doses received are within acceptable limits. These studies however, have been performed over short time-periods or have been confined to single procedures only. In this paper, we report the results of monitoring of the total exposure across all procedures of a group of orthopaedic surgeons over a 4-month period. Doses received were all below the International Commission on Radiological Protection (ICRP) recommended limits. While these results are reassuring, they do not represent grounds for complacency. Continued vigilance will be essential as work practices continue to change. In orthopaedics, in contrast with other specialties, the limiting dose is that to the hands. In view of this finding, extremity dosimetry for surgeons regularly using X-rays in theatre should be considered.

Surgical procedures in patients at risk of human immunodeficiency virus infection.

We have studied the outcome of 140 general surgical procedures in 112 patients known or suspected to be infected with human immunodeficiency virus (HIV) or hepatitis B virus. Forty patients had antibodies to HIV. A wide range of surgical procedures was performed, with an overall complication rate of 5.7%. Wound infection, wound haematoma and one unexplained pyrexia were the only complications seen. Some anorectal wounds in patients with HIV antibodies were noted to heal extremely slowly, but the aggressive anorectal sepsis reported by others was not seen. The postoperative course after general surgical procedures was unremarkable in patients with HIV antibodies, and in those suspected of HIV infection, but because anorectal wounds were found to heal slowly, we recommend that anorectal surgery be conservative in patients with HIV antibodies.

Puborectalis and external anal sphincter paralysis with preservation of fecal continence. Report of a case.

A case of poliomyelitis-induced paralysis of the puborectalis and external anal sphincter is described. This demonstrates the effect of an exclusively motor deficit of striated muscles controlling fecal continence. The patient has remained continent of feces for 37 years.

Stress-related disorders. Recent developments in hospital treatment.

The stress treatment program at Ochsner, New Orleans, provides participants with knowledge of necessary skills and opportunities for rehearsal and practice within the setting. In addition, the modalities chosen reinforce what Lazarus and Opton described as "perceived control," which was found to be as instrumental as actual control in anxiety reduction. Upon return to day-to-day living, participants have the opportunity to use skills acquired and to receive reinforcement for doing so. The staff and patients found that traditional supportive and/or insight-oriented psychotherapy was as important as the vast array of behavioral training measures for inclusion in the patient's daily schedule. Individual therapy was provided to each patient up to 45 minutes daily, and one-hour group psychotherapy sessions were conducted three times a week. The belief that individual attention, social support, and insight into previous learning were critical ingredients to the appeal of individual psychotherapy was borne out in patient follow-up questionnaire data. Patients who were followed at the time of discharge and at six months in the Clark and Stiles study consistently ranked "individual session with their doctor" high within the ranking of some 14 treatment modalities or experiences. Collectively, the average of such rankings demonstrated "individual session" of equal benefit with the "stress management session," a purely behavioral/stress inoculation training experience. Such data therefore supported our initial belief that a marriage of the best of what traditional psychotherapy can offer with the best of behavioral medicine provides the optimal opportunity for growth and symptom improvement.