Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Clinical outcomes and programming strategies of implantable cardioverter-defibrillator devices in paediatric hypertrophic cardiomyopathy: a UK National Cohort Study

AIMS

Sudden cardiac death (SCD) is the most common mode of death in paediatric hypertrophic cardiomyopathy (HCM). This study describes the implant and programming strategies with clinical outcomes following implantable cardioverter-defibrillator (ICD) insertion in a well-characterized national paediatric HCM cohort.

METHODS AND RESULTS

Data from 90 patients undergoing ICD insertion at a median age 13 (±3.5) for primary (n = 67, 74%) or secondary prevention (n = 23, 26%) were collected from a retrospective, longitudinal multi-centre cohort of children (<16 years) with HCM from the UK. Seventy-six (84%) had an endovascular system [14 (18%) dual coil], 3 (3%) epicardial, and 11 (12%) subcutaneous system. Defibrillation threshold (DFT) testing was performed at implant in 68 (76%). Inadequate DFT in four led to implant adjustment in three patients. Over a median follow-up of 54 months (interquartile range 28-111), 25 (28%) patients had 53 appropriate therapies [ICD shock n = 45, anti-tachycardia pacing (ATP) n = 8], incidence rate 4.7 per 100 patient years (95% CI 2.9-7.6). Eight inappropriate therapies occurred in 7 (8%) patients (ICD shock n = 4, ATP n = 4), incidence rate 1.1/100 patient years (95% CI 0.4-2.5). Three patients (3%) died following arrhythmic events, despite a functioning device. Other device complications were seen in 28 patients (31%), including lead-related complications (n = 15) and infection (n = 10). No clinical, device, or programming characteristics predicted time to inappropriate therapy or lead complication.

CONCLUSION

In a large national cohort of paediatric HCM patients with an ICD, device and programming strategies varied widely. No particular strategy was associated with inappropriate therapies, missed/delayed therapies, or lead complications.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Proximal Interphalangeal Joint Release in Dupuytren’s Disease of the Little Finger

We present a prospective study, with 3-year follow-up, of the role and outcome of fasciectomy plus sequential surgical release of structures of the proximal interphalangeal joint in Dupuytren’s contracture of the little finger.

Our treatment programme involves fasciectomy for all patients followed by sequential release of the accessory collateral ligament and volar plate as necessary.

Of the 19 fingers in the study, eight achieved a full correction by fasciectomy alone, and in these cases there was a fixed flexion deformity of 6° at 3 months and 8° at 3 years. The remaining 11 fingers (initial mean deformity 70° flexion) were left with a fixed flexion deformity of 42° after fasciectomy which reduced to 7° with capsuloligamentous release. This increased to 26° at 3 months but then remained relatively stable, increasing only to 29° at 3 years.

In our experience sequential proximal interphalangeal joint release has led to consistently good results with few complications in the correction of severe Dupuytren’s disease of the little finger.

Silicon nanowire arrays with enhanced optical properties

Vertical silicon nanowire arrays were fabricated leading to an enhanced photoluminescence (PL) emission and second-order nonlinear optical response. PL from the nanowires was increased by a factor of 50 as compared to bulk silicon. The second order nonlinearity was demonstrated in second-harmonic generation and rotational anisotropic measurements. Enhancement by at least a factor of 80 was achieved as compared to bulk silicon for the p-polarized input and s-polarized output. These enhancements in the silicon characteristics should enable highly desired applications using a silicon platform, such as nonlinear and active devices.

Morphometric sex determination of Milky and Painted Storks in captivity

Logistic regression was applied to develop a morphometric sexing method of two closely related stork species that were previously sexed through amplification of the CHD gene. Tarsus length (TL) and bill length (BL) measurements were recorded from captive populations of adult Milky Stork (Mycteria cinerea) (n = 60) and Painted Stork (Mycteria leucocephala) (n = 58) at Zoo Negara Malaysia. Despite having monomorphic plumages, both stork species exhibited normal sexual size dimorphism in which males were significantly larger than females in the tested variables. Based on logistic regression analysis, BL correctly classified the sex of sampled individuals from Painted and Milky stork with an overall predicted accuracy of 94.8 and 90.0%, respectively. However, TL measurements generated a lower predicted accuracy level of 86.2% and a same accuracy level of 90% on the sex classification of individuals from Painted and Milky stork, respectively. By comparing the measurements of both species, only the average BL measurements of the Milky storks were significantly lower than that of Painted storks (t-test, P80.001). The logistic regression equation in this study may serve as a simple and more practical option for sexing Milky and Painted storks for their breeding and conservation programmes.

Radiological assessment of type II Stafne idiopathic bone cyst in a patient undergoing implant therapy: a case report

This paper is intended to describe the confirmative role of radiology in the diagnosis of Stafne Idiopathic bone Cyst (SIBC) without the need for histopathology especially when dental implants are considered so as to avoid unnecessary invasive surgical exploration of this benign pathology. Other pathologies may present not unlike SIBC and as such it is mandatory to rule out such possibilities especially prior to dental implant therapy. The use of orthopanthomogram and non-sialographic computed tomography (CT) scan in the reported case together with a review of CT scan confirmatory role in the diagnosis of SIBC from the literature was the basis for this clinical report. Based on the CTscan findings of the jaw in this case and review of the literature, the implant procedure was commenced without the need of histopathology and/or for invasive surgical exploration of this pathology. All pathologic lesions of the jawbone seen on the orthopanthomogram should be confirmed prior to commencement of implant procedure even when such pathologies are seen in areas remote from the proposed implant site. The pre-implant radiological assessment utilizing non-sialographic CT scan alone is confirmatory of SIBC.

GammaPlan-Leksell Gamma Knife radiosurgery treatment planning verification method

This work provides a method for an independent check of Gamma Knife GammaPlan radiosurgery calculations, named the spherical approximation method or SAM. Based on skull dimension measurements, the treated volume of the head is modeled as a sphere of radius R. With this approximation, an analytical solution for fast ray tracing of the path length, for each of the 201 beamlets, of the Gamma Knife helmet collimator was possible. The dose rate at the focus of a single shot is the sum of the contributions of all active beamlets adjusted for both the collimator factor and attenuation. For an arbitrary point, the dose rate is derived at the beamlet level from the focus values adjusted for the new path length attenuation and the appropriate collimators' off-axis profiles. The sum over all beamlets' contributions gives the dose rate at that particular point. At the single shot level, SAM independent check results agree with the GammaPlan for patient calculations to better than +/-6% and, as expected, in spherical phantoms the agreements improve to better than +/-1.0%. For an arbitrary point, multi-shot procedure, the agreement is better than +/-3% and +/-1.5, respectively.

Psychostimulants, adult attention deficit hyperactivity disorder and morbid jealousy

OBJECTIVE

This paper aims to discuss the relationship between morbid jealousy, stalking behaviour, and psychodynamic issues. Comment will be made on the risk associated with diagnosis of adult attention deficit hyperactivity disorder (ADHD) and use of psychostimulants.

CLINICAL PICTURE

A man born in the former Yugoslavia charged with stalking was referred for assessment. He presented with a history of treatment for ADHD with dexamphetamine and delusions regarding his wife's fidelity.

TREATMENT

The patient was treated with neuroleptics and counselling for himself and his family.

OUTCOME

The patient was returned to the community. He separated from his wife but retains the abnormal belief.

CONCLUSIONS

The diagnosis of adult ADHD appears to be increasing in Western Australia. Treatment with stimulants is common. The misdiagnosis of ADHD and consequent misuse of stimulants, can lead to the development of morbid jealousy, stalking behaviour and arrest.

Prevalence of taurodontism in Jordanian dental patients

OBJECTIVES

To assess the prevalence of taurodontism in a group of Jordanian adult dental patients.

METHODS

Posterior periapical radiographs of 875 unselected dental patients were examined for the presence of taurodontism defined as the presence of an apically displaced pulp chamber without the usual constriction at the cemento-enamel junction.

RESULTS

Taurodontism was detected in 8% of subjects and 4.4% of the teeth examined. The maxillary second molar was the most commonly affected tooth. It was equally distributed between males and females (7.9% compared with 8.1% respectively, P > 0.05). 26.7% of the taurodont teeth also had pulp stones or calcifications.

CONCLUSION

Taurodontism is not uncommon in Jordan but further larger scale studies are required to assess its prevalence in the general population to compare it with other ethnic groups.

Oral lesions in a Jordanian population

Since there is little information available on the prevalence of oral lesions in the Middle East population generally, and no data on the Jordanian population, this study was undertaken to correct this deficiency in our knowledge. During this investigation 2175 consecutive asymptomatic dental patients attending the Initial Treatment Unit in the Faculty of Dentistry, Jordan University of Science and Technology were examined for the presence of oral lesions. A total of 30 different oral lesions and conditions were diagnosed. Fordyce's granules and tori were the most common conditions diagnosed in 49 per cent and 15.7 per cent of the subjects respectively. Larger scale studies are required on an unselected group of the Jordanian population to assess the overall significance of the findings.

Dosimetric measurement of scattered radiation from dental implants in simulated head and neck radiotherapy

The purpose of this study was to examine the dose enhancement at bone-implant interfaces from scattered radiation during simulated head and neck radiotherapy. Three cylindric implant systems with different compositions (pure titanium, titanium-aluminum-vanadium alloy, titanium coated with hydroxyapatite) and a high gold content transmandibular implant system (gold-copper-silver alloy) were studied. Extruded lithium fluoride single crystal chips were used as thermoluminescent material to measure radiation dose enhancement at 0, 1, and 2 mm from the bone-implant interface. The relative doses in buccal, lingual, mesial, and distal directions were also recorded and compared. The results indicated that the highest dose enhancement occurred at a distance of 0 mm from the bone-implant interface for all the implant systems studied. The transmandibular implants had higher scattered radiation than other groups at 0 mm and at 1 mm from the bone-implant interface. There was no significant difference of dose enhancement between buccal, lingual, mesial, and distal directions. Titanium implants coated with hydroxyapatite demonstrated the best results under the simulated irradiation.

Randomized, double-blind, placebo-controlled study of supplemental oral L-arginine in patients with heart failure

BACKGROUND

Patients with heart failure have reduced peripheral blood flow at rest, during exercise, and in response to endothelium-dependent vasodilators. Nitric oxide formed from L-arginine metabolism in endothelial cells contributes to regulation of blood flow under these conditions. A randomized, double-blind crossover study design was used to determine whether supplemental oral L-arginine can augment peripheral blood flow and improve functional status in patients with moderate to severe heart failure.

METHODS AND RESULTS

Fifteen subjects were given 6 weeks of oral L-arginine hydrochloride (5.6 to 12.6 g/d) and 6 weeks of matched placebo capsules in random sequence. Compared with placebo, supplemental oral L-arginine significantly increased forearm blood flow during forearm exercise, on average from 5.1 +/- 2.8 to 6.6 +/- 3.4 mL. min-1. dL-1 (P < .05). Furthermore, functional status was significantly better on L-arginine compared with placebo, as indicated by increased distances during a 6-minute walk test (390 +/- 91 versus 422 +/- 86 m, P < .05) and lower scores on the Living With Heart Failure questionnaire (55 +/- 28 versus 42 +/- 26, P < .05). Oral L-arginine also improved arterial compliance from 1.99 +/- 0.38 to 2.36 +/- 0.30 mL/mm Hg (P < .001) and reduced circulating levels of endothelin from 1.9 +/- 1.1 to 1.5 +/- 1.1 pmol/L (P < .05).

CONCLUSIONS

Supplemental oral L-arginine had beneficial effects in patients with heart failure. Further studies are needed to confirm the therapeutic potential of supplemental oral L-arginine and to identify mechanisms of action in patients with heart failure.

In vitro backscattering from implant materials during radiotherapy

It is a certainty that many of the patients now receiving dental implants will one day require radiotherapy if they have head and neck cancer. The purpose of this study was to examine the dose enhancement form backscattered radiation at implant/bone interfaces irradiated with high-energy 6 MV and 10 MV x-rays. Three commonly used implant materials, pure titanium, Ti-6A1-4V alloy, and a high gold content implant material of various thicknesses, were used to measure the dose enhancement caused by backscattered radiation. The relative ionization charges at implant/bone interfaces were measured at distances of 0, 1, 2, and 3 mm away from the implant material by insertion of 0, 1, 2, and 3 mm thick bone substitute disks between the implant material and an ionization chamber. The results indicated that the highest dose enhancement occurred at a distance of 0 mm from the implant/bone interface for all the materials studied. The Au-Cu-Ag implant material had more average relative dose than pure titanium or Ti-6A1-4V alloy. The backscattered electrons decreased as the thickness of the bone substitute (distance between the implant material and the ionization chamber) increased.

Lipid and fatty acid composition of muga silkworm, Antheraea assama, host plants in relation to silkworm growth

The lipid and fatty acid composition of the leaves (tender, medium and mature) of muga host plants, Machilus bombycina, Litsaea monopetala (primary food plants) and L. cubeba and L. salicifolia (family: Lauraceae) (secondary food plants) was investigated by standard procedures, gas chromatography after saponification and esterification. The total lipid content of M. bombycina and L. monopetala leaves was recorded to be higher (16 and 18 g%), respectively, than that of L. cubeba (10 g%) and L. salicifolia (12 g%). GC analysis identified the presence of eight fatty acids (C14 to C22) and the concentration varied from 0.0297 to 8.1572 g% dry leaf powder. Among the fatty acids, (C14 to C22), polyunsaturated fatty acids were recorded to be highest in concentration in mature leaves of the primary host plants. The concentrations of saturated and polyunsatuated fatty acids were found to be at a minimum level in all the types of leaves of secondary muga host plants.

Shotgun wounds and pellet emboli: case reports and review of the literature

Shotguns produce extensive tissue damage when victims are injured at close range. Arterio-arterial and veno-venous pellet emboli may result when major vessels or their tributaries are injured. Management of the pellet embolus is dictated by whether it is symptomatic or asymptomatic. Regardless of symptoms, the embolus is a sign of possible major vascular or venous tributary injury. We recently managed two cases of pellet emboli produced by close range shotgun wounds. This report describes our management of these injuries and collectively reviews the past 30 years of literature on shotgun wounds with arterio-arterial and veno-venous pellet emboli. Recommendations for management are suggested from collating the cases reported in the literature.

Prevalence of tongue lesions in 1013 Jordanian dental outpatients

Over a period of 10 months, 1013 consecutive dental outpatients attending the Screening Clinic in Faculty of Dentistry, Jordan University of Science and Technology, in the city of Irbid were investigated for the presence of tongue lesions. All subjects were seeking treatment for caries and periodontal diseases and none was complaining of oral mucosal disorder. The results showed that 240 subjects (23.7%) had one or more tongue lesions. Geographic tongue and fissured tongue were detected in 6.8% and 11.4% of the examined population respectively, and an association of the two conditions was observed in 2.9% of the subjects. Hairy tongue was diagnosed in 3.4% of the subjects with significantly higher prevalence in males (P < 0.0005). A strong correlation was found between hairy tongue and smoking.

Use of a silicone dual-lumen catheter with a Dacron cuff as a long-term vascular access for hemodialysis patients

We evaluated our experience over a 4-year period with a silicone dual-lumen catheter with a Dacron cuff (SDLCDC) to determine if the catheter represents an alternative to the polytetrafluoroethylene graft for long-term vascular access for hemodialysis patients. Records of 131 patients who used 168 catheters were reviewed for catheter function, duration of use, and occurrence and response to treatment of complications. Eighty-five percent of catheters functioned adequately until their use was no longer required or the end of the study. One-year catheter survival estimate was 65% and median survival estimate was 18.5 months. Mean blood flow rate achieved was 243 mL/min and recirculation was 7.5%. Exit-site infection occurred in 21% of patients and bacteremia in 12%. There were significantly more exit-site infections in diabetics than nondiabetics (33% v 11%, P less than 0.02). Exit-site infections resolved with parenteral antibiotic therapy in 90% and bacteremia in 25% of cases without catheter removal. Unresolved bacteremia was the most common cause of catheter removal and led to the loss of 7% of catheters. Thrombotic complications occurred in 46% of catheters. Urokinase instillation successfully treated catheter occlusion in 81% of cases. When urokinase instillation failed, streptokinase infusion restored catheter patency 97% of the time. The literature on the polytetrafluoroethylene (PTFE) graft was reviewed, and the SDLCDC was found to be similar to the graft in function, duration of use, and frequency of infectious and thrombotic complications. We conclude that the catheter represents an alternative to the graft for long-term vascular access in hemodialysis patients. Because of the frequent complications with both accesses, neither should be considered optimal. Further research is required to improve vascular access for patients in whom placement of an arteriovenous fistula is not possible.