Development and internal validation of clinical prediction models for outcomes of complicated intra-abdominal infection

BACKGROUND

Complicated intra-abdominal infections (cIAIs) are associated with significant morbidity and mortality. The aim of this study was to describe the clinical characteristics of patients with cIAI in a multicentre study and to develop clinical prediction models (CPMs) to help identify patients at risk of mortality or relapse.

METHODS

A multicentre observational study was conducted from August 2016 to February 2017 in the UK. Adult patients diagnosed with cIAI were included. Multivariable logistic regression was performed to develop CPMs for mortality and cIAI relapse. The c-statistic was used to test model discrimination. Model calibration was tested using calibration slopes and calibration in the large (CITL). The CPMs were then presented as point scoring systems and validated further.

RESULTS

Overall, 417 patients from 31 surgical centres were included in the analysis. At 90 days after diagnosis, 17.3 per cent had a cIAI relapse and the mortality rate was 11.3 per cent. Predictors in the mortality model were age, cIAI aetiology, presence of a perforated viscus and source control procedure. Predictors of cIAI relapse included the presence of collections, outcome of initial management, and duration of antibiotic treatment. The c-statistic adjusted for model optimism was 0.79 (95 per cent c.i. 0.75 to 0.87) and 0.74 (0.73 to 0.85) for mortality and cIAI relapse CPMs. Adjusted calibration slopes were 0.88 (95 per cent c.i. 0.76 to 0.90) for the mortality model and 0.91 (0.88 to 0.94) for the relapse model; CITL was -0.19 (95 per cent c.i. -0.39 to -0.12) and - 0.01 (- 0.17 to -0.03) respectively.

CONCLUSION

Relapse of infection and death after complicated intra-abdominal infections are common. Clinical prediction models were developed to identify patients at increased risk of relapse or death after treatment, these now require external validation.

Use of the embedded peritoneal dialysis catheter

Introduction The use of embedded peritoneal dialysis (PD) catheters is purported to offer numerous benefits over standard placement. However, the optimum period of embedment and the effect of prolonged embedment on subsequent catheter function remain unclear. Methods This retrospective observational study looked at adult patients undergoing embedded PD catheter insertion in a large tertiary referral centre in the UK. Possible predictors for catheter non-function at externalisation were investigated. These included patient factors (age, sex, diabetic status, body mass index, ethnicity, smoking status, previous surgery, estimated glomerular filtration rate), procedural factors (modality of surgery, concurrent surgical procedure), duration of catheter embedment and catheter damage at externalisation. Outcomes examined were proportion of catheters functioning after externalisation, futile placement rate, surgical reintervention rate, infectious complication rate and proportion of externalised catheters lost owing to malfunction. Results Sixty-six catheters were embedded and two-thirds (n=47, 63.6%) were externalised after a median embedment period of 39.4 weeks. Of these, 25 (53.2%) functioned on externalisation. Fourteen (63.6%) of the 22 non-functioning catheters were salvaged. The overall utilisation of PD was 34/47 (72.3%) and the futile placement rate was 12.1%. Over half of the externalised catheters (n=27, 57.4%) were lost directly as a result of catheter related complications, with a median survival time of 39.4 weeks. In adjusted analysis, increasing embedment duration was significantly predictive of catheter non-function at externalisation (adjusted odds ratio: 0.957, 95% confidence interval [CI]: 0.929-0.985, p=0.003) while subsequent catheter loss was highly dependent on catheter function at externalisation (hazard ratio: 0.258, 95% CI: 0.112-0.594, p=0.001). Conclusions Prolonged embedment of PD catheters is associated with a significantly higher likelihood of catheter dysfunction following externalisation, which is in turn associated with subsequent catheter loss. We have discontinued the use of this technique in our unit.

159 TWIN vs. SINGLE TRANSFER OF IVP HOLSTEIN HEIFER EMBRYOS TO BEEF RECIPIENTS

Use of sexed semen in conjunction with in vitro embryo production is a potentially efficient means of obtaining offspring of predetermined sex. Here we evaluate a production scheme involving single and bilateral twin transfer of Holstein female embryos to beef cattle recipients. Holstein oocytes were fertilized with the X-bearing fraction of gender-sorted Holstein semen. Cumulus cells were removed with aid of a vortex or microfluidic device (μFD). Half of the vortexed embryos were cultured in KSOMaaBSA (control), as were all μFD embryos. The remaining vortexed embryos were cultured in control medium with 6% avian white yolk (WY). Embryo production and transfer occurred across five replicates. Cows (n = 475) were synchronized using an Ovsynch protocol. They were administered GnRH on Day −9, PGF on Day −2, and GnRH on Day 0. Half of the cows received a CIDR (1.38 g progesterone) with the 1st GnRH injection. The CIDR was removed at the time of PGF treatment. Day 7 Grade 1 blastocysts were transferred fresh 7 days after the 2nd GnRH injection. Control and WY embryos were transferred as ipsilateral singles and bilateral twins; μFD embryos were transferred singly. Pregnancy was diagnosed with ultrasound between 41–46 days and confirmed between 60–90 days; fetal sexing confirmed that 95% of fetuses were female. Effects on embryo survival were analyzed by logistic regression. Chi-square analysis was applied to survival rates. Replication affected embryo survival (P < 0.05). There was no effect of cumulus removal, medium, or CIDR use. Fetal loss between ultrasounds was greater for twin vs. single transfers (30% vs. 15%, respectively; P < 0.01). Probability of embryo survival was estimated to increase ∼0.006 with each increasing day postpartum. Five cases of hydrallantois were detected during the 5th month of gestation for 1 control twin, 1 WY single, and 3 WY twin transfers, originating from 3 replicates. On a production per transfer basis, the proportion of fetuses obtained for single and twin transfers was 30% and 55%, respectively (P < 0.001). Although there was greater embryonic loss for twin compared to single transfers, a higher percentage of cows receiving twins established and maintained pregnancy. Large-scale transfer of IVP Holstein heifer embryos to beef recipients is a feasible production scheme. Table 1. Embryo survival and pregnancy rates

156 ENHANCED BOVINE EMBRYONIC DEVELOPMENT AFTER MICROFLUIDIC CUMULUS CELL REMOVAL POST-FERTILIZATION

Microfluidic technologies are increasingly being used in cell biology and embryology research. In order to manipulate an embryonic environment microfluidics take advantage of miniscule media amounts. With the use of pressure heads and laminar flow profiles, a presumptive zygote can be gently manipulated in a microfluidic device for removal of the supporting cumulus cells post-fertilization. Presumptive embryos were assigned at random to three cumulus removal treatments at 48 h post-fertilization: vortexing (3 min), handstripping (with 135-μm-ID stripping pipette), and microfluidics. Blastocyst rates were determined through Day 8 post-fertilization. Rates were analyzed by the GENMOD procedure in SAS (SAS Institute, Inc., Cary, NC, USA), accounting for replicates and treatment. Kinetics of development were also impacted as larger proportions of embryos in the microfluidic group reached the blastocyst stage before embryos of the vortex or hand-stripping treatments. These data suggest that cumulus cell removal in a gentle fashion is associated with enhanced embryonic development in the bovine. Table 1. Comparison of cumulus cell removal techniques on bovine blastocyst rates

Salvage cryosurgery for locally recurrent prostate cancer following radiotherapy

The popularity of radiotherapy as a minimally invasive treatment for prostate cancer is increasing. Despite advancements in radiation delivery, a number of patients will fail treatment. Salvage radical prostatectomy has been the main therapeutic option for locally recurrent radiation failure prostate cancer with curative intent. The operation is technically difficult to perform and associated with significant comorbidities. Salvage cryotherapy has emerged as a minimally invasive alternative option. In this article, we review the role of cryotherapy in recurrent prostate cancer and compare its outcome with salvage radical prostatectomy.

Comparison of the subvastus and paramedian surgical approaches in bilateral knee arthroplasty

A prospective randomized study was performed on 20 patients undergoing one-stage bilateral knee arthroplasty. One knee was exposed using a standard median parapatellar arthrotomy and the other knee with a subvastus arthrotomy. All patients underwent quantitative strength testing before surgery and at 1 week, 1 month, and 3 months after surgery. The knees were also evaluated for range of motion, and patients, who were blinded as to the approach used, completed questionnaires at each evaluation period as to their preference, if any, regarding knee pain and level of function. There was no difference in the range of motion between knees exposed with the paramedian or subvastus arthrotomy at any time period. The subvastus knees demonstrated significantly greater strength at the 1-week and 1-month intervals, but there was no strength difference at the 3-month interval. There were more lateral releases performed in the paramedium knees, and three minor complications were related to the subvastus approach. Patients who expressed a preference chose the subvastus knee 4:1 over the paramedian knee. The subvastus approach offers a reasonable alternative to the paramedian arthrotomy and preserves greater quadriceps strength in the early postoperative period.

Cold and heat application in musculoskeletal injury

In physical therapy there is rarely the opportunity to see patients in the very acute stage, but early intervention by emergency nurses can be the key to faster healing. Follow-up visits in a physical therapy clinic can reinforce proper use of thermomodalities in the home and can introduce appropriate movement techniques, therapeutic exercise programs, RECIPE, hydrotherapy, and modalities for pain to regain function as quickly and as safely as possible.

The relationship of allergies and allergy treatment to school performance and student behavior

The purposes of this project were to study the relationship of allergies and allergy treatment to school behavior. Parents of allergic and nonallergic children (grades K-12 and from different socioeconomic status) completed a survey form. The 400 parent respondents reported no significant difference between allergic and nonallergic children in terms of academic and language performance, retention, diagnosis as handicapped, or behavior problems; allergic children were absent from school more. Eustachian tube dysfunctions were significantly related to academic and behavior problems. Certain medications were related to overactive types of behavior. Parents who considered their children's behavior as inappropriate tended to contribute a portion of it to side effects of medication. 65% of the parents reported positive results from treatment on behavior at home; they tended to be unsure of the impact on school behavior. Direct relationship of allergy and allergy treatment on academic performance is questionable, except for the impact of upper respiratory problems on listening and attention. Use of certain medications with already behavior disordered children requires caution. Better communication among physicians, teachers and parents is advised.