Operative Exposure Research Articles

Influence of the transient conditions on release of corrosion products and oxidation of alloy 690 tubes during pressurized water reactor restart after steam generators replacement

The radioactivity of the Reactor Coolant System (RCS) of Pressurized Water Reactors (PWRs) mainly comes from the release of corrosion products of Steam Generator (SG) tubes made of Ni-base alloys. In order to reduce this activity and thus the radiation exposure of PWR operators during maintenance operations, it is necessary to minimize the release. That requires prior understanding of the various mechanisms involved. EDF R&D constructed a loop, BOREAL, to specifically measure rates of release of SG tubes in various conditions of primary environment. Tubes were usually tested at high temperature, under constant conditions of primary chemistry. So, it is necessary to carefully investigate the impact of transient conditions during a PWR restart after SG replacement. Tests were performed on the industrial material with curvature, roughness, defects and heterogeneities, regularly observed on this type of component. Characterisations of the inner surface were done on as-received and corroded specimens of SG tubes and were correlated with the obtained release kinetics.The native oxide layer is formed of a very thin layer (1-2 nm) of oxidised matrix, without specific enrichment. During the restart, the most critical step for the release phenomenon is revealed from 170°C to 297°C. The majority of the metal is indeed released into the fluid during this step. The characterisations after release tests have made it possible to propose oxidation and release mechanism during a PWR restart after SG replacement. Up to 170°C, a thin layer of amorphous chromium oxide is formed by selective dissolution of iron and nickel. When the temperature rises, this chromium oxide layer is not stable enough to be protective and the diffusion phenomena are activated. At 325°C, the oxide does not exhibit any particular enrichment and corresponds to an oxidised metal layer; an equilibrium is established and the rate of release reaches a pseudo-stationary regime.

Comparison of air dose and operator exposure from portable X-ray units.

This study was aimed at investigating and comparing exposure dose of workers and the surrounding workers. In addition, worker's exposure was also measure about lens and finger. Four intraoral portable X-ray units were evaluated. The stray radiations were measured using Pitman 37D and ionization chamber (Pitman). MyDosemini (ALOKA) was used for measurement of the finger exposure dose. Without the shield became high in anterior 0.5m. Comparing the air dose for the four models used in this study showed a high tendency for the two NOMAD models. And using the shields, the images could be taken 4.6 times of the baseline at a maximum and 3.6 times on average. The finger radiation exposure dose was low with both of the NOMAD models, with no significant difference found. By setting the baseline value without a shield, finger radiation exposure when using a shield was lower than the detection limit for the D3000, and was reduced by approximately 94-96% for other three models. All models can photograph around 100 bodies, so it is considered that it is not necessary to switch out the operator considering the operation limit. But even if it does not reach the operation limit, the stochastic effects of radiation exposure can be increased as well as the deterministic effects of the operation limit. The operator and the surrounding workers seek to protect themselves. It is important to perform exposure management that takes into account the stochastic effects to the operator and the surrounding workers.

ACGME Operative Case Log Accuracy Varies Among Surgical Programs

This study evaluates the accuracy of reported the Accreditation Council for Graduate Medical Education (ACGME) operative case logs from graduated residents compared to institutional operating room electronic records (ORER). We hope this will help guide review committees and institutions develop complete, accurate resident case logs. This is a retrospective, cross-sectional study of general surgery (GS), neurosurgery (NS), and orthopedic surgery (OS) resident physicians. ACGME and ORER cases from 2009 to 2010 were analyzed and each case and current procedural terminology (CPT) code directly compared (ORER vs. ACGME). Single academic tertiary-care medical center (University of Kentucky, Lexington, KY). Eleven thousand nine hundred and twenty-three cases for 46 residents among the 3 residency programs were analyzed. There was an overall logging accuracy of 72% for ORER cases reflected in the ACGME case logs. OS residents had a higher rate of logging accuracy (OS 91%, GS 69%, NS 58%, chi-square p = 0.014) and mean annual number of cases compared to the other 2 programs (OS 452, GS 183, NS 237, ANOVA p = 0.001). NS residents had higher accuracy of CPT codes than post-graduate years 2 to 5 in other programs (p < 0.017). There was a strong positive correlation between the number of cases completed per resident and case logging accuracy, (rho = 0.769, p < 0.001) consistent for NS and GS, but not OS. This study shows only 72% of a residents' operative experience is captured in the ACGME case log across 3 surgical programs. There is significant variability among surgical programs and among post-graduate year cohorts regarding case log and CPT code accuracy. There is a strong correlation with the total number of cases performed and increasing case log accuracy. Low case log accuracy may reflect individual resident behavior instead of program operative exposure. Further studies are needed to determine if ORER may serve as a more complete assessment of the operative experience of a resident and program.

Effectiveness of a radiation protective device for anesthesiologists and transesophageal echocardiography operators in structural heart disease interventions.

In structural heart disease (SHD) interventions, the exposure of staff other than the first operator such as anesthesiologists and transesophageal echocardiography (TEE) operators to the radiation can also pose the risks of cancer and cataracts in the long term. This study was conducted to test our new radiation protective device (RPD) for anesthesiologists and TEE operators in SHD interventions. The RPD, which consists of a head side shield and a cradle shield, was mounted on a 0.25 mm Pb-equivalent unleaded radiation protection sheet on a self-made J-shaped acrylic table, and it was placed on the head side and cradle on the operating table. A CT human body phantom was placed on the operating table, and the C-arm was set in five directions: posteroanterior, right anterior oblique 30°, left anterior oblique 30°, caudal 30°, and cranial 30°. The ambient dose equivalent rate at the usual positions of the anesthesiologist and TEE operator were measured under a fluoroscopic sequence with and without the RPD, and the dose reduction rate was obtained. The height of each measurement point was set to 100, 130 or 160cm. The reduction rates at the positions of the anesthesiologist and the TEE operator were 82.6-86.4% and 77.9-89.5% at the height of 100cm, 48.5-68.4% and 83.3-91.0% at 130cm, and 23.6-62.9% and 72.9-86.1% at 160cm, respectively. The newly developed RPD can thus effectively reduce the radiation exposure of anesthesiologists and TEE operators during SHD interventions.

Dose-reducing fluoroscopic system decreases patient but not occupational radiation exposure in chronic total occlusion intervention.

Several novel low-dose fluoroscopic systems (LDS) developed recently, but real practice information of the net benefit for the patient and professionals is scarce. We evaluated separately patient and operator radiation exposure during percutaneous interventions of chronic total occlusions (CTO). A total of 116 consecutive CTOs were analyzed (60 in LDS and 56 in standard-dose fluoroscopic system [SDS]). Digital dosimetry of patient and occupational (operator and scatter dose) exposure was prospectively recorded. Biometrics, demographics, CTO variables, and operators were distributed evenly. Patient radiation exposure was effectively decreased in LDS (dose area product [DAP] by 36%, Air Kerma [AK] by 47%). However, occupational data showed no statistical differences between LDS and SDS. The LDS uses less radiation amount but with higher energy (due to additional filtration) compared to SDS, therefore increasing the scatter dose. When comparing the C-arm scatter dose to the DAP we found higher scatter dose with the LDS (0.0139 mSv/gray (Gy)*cm2 vs. 0.0082 mSv/Gy*cm2, p < .001). This was confirmed in a larger dataset comprising 5,221 coronary procedures. LDS was safer for patients reducing DAP and AK compared to SDS. However, occupational doses were not lower and scatter dose higher. Radiological protection measures must be kept maximized even in LDS.

Application of quadriceps snip in complex total knee arthroplasty

To explore the safety and effectiveness of quadriceps snip in complex total knee arthroplasty (TKA). A clinical data of 19 cases (29 knees) with complex TKA assisted with quadriceps snip between January 2016 and May 2017 were retrospectively analyzed. There were 9 males (13 knees) and 10 females (16 knees). The age of patients ranged from 34 to 66 years (mean, 50.2 years). Four patients (8 knees) were ankylosing spondylitis, 5 patients (7 knees) were rheumatoid arthritis, and 10 patients (14 knees) were knee osteoarthritis. The average disease duration was 10.9 years (range, 8-15 years). There were 12 knees of Kellgren-Lawrence grade Ⅲ and 17 knees of Kellgren-Lawrence grade Ⅳ. The range of motion (ROM) of knee was (19.86±7.23)°. The clinical and function scores of knee society score (KSS) were 47.86±11.26 and 15.52±11.21, respectively. Postoperative complications, ROM, KSS scores, extensor lag, and prosthesis loosening were observed to evaluate the effectiveness. All incisions healed by first intention, and no infection or cardiovascular and cerebrovascular accidents occurred. All patients were followed up 25-39 months (mean, 30.3 months). At last follow-up, the ROM of knee was (91.03±7.30) °, the KSS clinical score was 83.62±9.99 and functional score was 66.38±7.89, showing significant differences when compared with preoperative ones ( P<0.05). Postoperative extensor lag (10°, 10°, 15°) occurred in 3 cases. There was no evidence of prosthesis loosening or osteolysis on X-ray films during follow-up. The application of quadriceps snip in complex TKA can effectively improve the operative field exposure and reduce incidence of complications such as patella tendon tearing, patella fracture, and quadriceps tendon injury. The surgical technique of Krackow tendon suture can effectively guarantee early rehabilitation without occurrence of other complications.

A Retrospective Review of Differences in Complication Rates between Dorsal Percutaneous and Mini-Open Surgical Fixation of Scaphoid Fractures.

Objective We retrospectively reviewed the complications of 80 cases of scaphoid screw fixation in acute fractures and early nonunions comparing dorsal percutaneous and mini-open approaches. Methods We performed a chart review of all patients who underwent surgical fixation of a scaphoid fracture or a nascent nonunion using a dorsal percutaneous or dorsal mini-open technique by a single surgeon. We collected data on patient demographics, including age and smoking status, time to surgery, fracture type, union, and the major and minor complications that occurred in each group. Fisher's exact tests were used to compare the complication rates between the groups. Results We identified 80 patients who underwent surgical fixation. Of these, 44 underwent percutaneous fixation and 36 underwent mini-open fixation. All fractures went on to heal. There was a total of five complications identified. There were no major complications in the percutaneous group, but one major complication in the mini-open group (a delayed union that eventually healed at 6 months). There were two minor complications in each group. There was no statistically significant difference in total, major, or minor complication rates between the groups. Conclusions This study suggests that a dorsal percutaneous surgical technique for scaphoid fracture repair does not affect the complication rate despite prior literature to the contrary. Both techniques analyzed produce excellent rates of union with very low complication rates. Surgeon-specific technique rather than operative approach or exposure may be responsible for previously reported complication rates in the fixation of scaphoid fractures. Level of Evidence This is a level III, therapeutic study.

Association between distance from the radiation source and radiation exposure: A phantom‐based study

The study evaluated the association between distance from radiation source and radiation exposure. Radiation exposure during medical procedures is associated with increased risk of cancer and other adverse effects. An American National Standards Institute phantom was used to study the relationship between measured entrance surface exposure (MESE) and distance from the X-ray source in postero-anterior, left anterior oblique, and right anterior oblique projections. Three distance settings for table height were evaluated with "low" defined as 52 cm, "mid" 66 cm, and "high" 80 cm from the focal point of the X-ray source. Air-kerma and dose-area product measurements were recorded. Operator exposure with each of these conditions was measured, in a short operator (150 cm) as well as in a tall operator (190 cm). Aggregate results for the three projections were as follows. MESE (μGy/frame) significantly decreased as table-height increases (median, interquartile range, p-value) (low table-height 192.5 [122.4-201.2], mid table-height 105.8 [82.7-115.8], and high table-height 71.7 [58.4-75], p < .0005). The operator exposure (μGy/frame), significantly increased as the table-height increased (low table-height 0.0943 [0.0598-0.1157], medium table-height 0.1128 [0.0919-0.1397], and high table-height 0.158 [0.1339-0.2165], p < .0005). A shorter operator received higher radiation exposure compared to a taller operator (short operator 0.1405 [0.1155-0.1758] and tall operator 0.0995 [0.0798-0.1212], p < .0005). Increasing table-height is associated with a significant decrease in MESE. Operator radiation exposure increases with increasing table-height and shorter operators receive greater radiation exposure compared to taller operators.

P104. A review of time demand, radiation exposure and outcomes of skin-anchored intraoperative 3D navigation in minimally invasive posterior cervical laminoforaminotomy

BACKGROUND CONTEXT Real time image-guidance and intra-operative 3-dimensional navigation (ION) are increasingly being utilized in spine surgery to provide better visualization, improve accuracy and enable less invasive procedures. Studies have shown effective early adaption and radiation reduction with this technology in minimally invasive lumbar spine surgery. However, the novel use of a noninvasive skin-anchored tracker has not yet been described for cervical spine surgery. PURPOSE To describe the time demand, radiation exposure and outcomes of ION using a skin-anchored tracker in minimally invasive posterior cervical laminoforaminotomy (MI-PCLF). STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE All patients who underwent MI-PCLF by a single surgeon from April17-November 19. OUTCOME MEASURES Time for navigation set-up, operative time, estimated blood loss (EBL), radiation exposure to operating room (OR) personnel and the patient, complications and length of stay. METHODS Operative variables, radiation exposure and perioperative outcomes were summarized using descriptive statistics. RESULTS Twenty-one patients (36Levels) with a mean age of 55+11.79yrs, BMI of 27.36+2.95kg/m2, and comprising 17(81%) males were included. A majority of cases were 1-level (9; 42.9%) or 2-level (10; 47.6%), with only one 3-level and one 4-level surgery. The operative levels were: C3C4 (11.1%), C4C5 (19.4%), C5C6 (22.2%), C6C7 (25%), C7T1 (22.2%). Time required for ION set-up, measured as the time from end of anesthesia induction to the start of the surgical procedure was a median of 34 mins [IQR 30-37]. This accounts for the time required for patient positioning, preparing and draping the incision site, placing the skin-anchored navigation tracker and acquiring a 3D image for real-time navigation. The total fluoroscopy time was a median of 10 sec [IQR 9-11], almost entirely attributable to ION image-acquisition; and radiation dose was a median of 2.5mGy [IQR 1.8-4.9]. Thus, radiation exposure to the patient was minimal. Since all OR personnel are behind a protective lead shield during ION image-acquisition, radiation exposure to the surgeon and OR team was negligible. One patient required a repeat ION spin, resulting in the fluoroscopy time for ION image-capture being 20sec. In two patients, ION was abandoned and the procedure was completed using fluoroscopy resulting in the total fluoroscopy time being 17&27sec (9sec for ION spin; rest for fluoroscopic guidance). Additionally, one patient had a radiation dose of 13.9mGy, which is almost three times the 75th percentile dose. Although the exact reason could not be determined, this may be attributable to a number of factors including deliberate or inadvertent higher dose settings, difference in C-arm position, calibration error, etc. Operative time was 62 mins [IQR 53-74] and EBL was low (25ml [IQR 25-25]. There were no wrong level surgeries, or any intra or post-operative complications. Median post-operative length of stay was 6hrs [IQR 4.4-20.9], with a majority (66.7%) of patients being discharged on the day of surgery. CONCLUSIONS The results of our study suggest that the use of intraoperative navigation using a skin-anchored tracker for posterior cervical laminoforaminotomy is a feasible, safe and accurate technique, resulting in short operative times and minimal complications. Further, it results in negligible radiation exposure to the OR team and low radiation exposure to the patient. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Endoscope-assisted transoral resection of parapharyngeal space tumors: a retrospective study

Objective:To evaluate the feasibility and safety of the endoscope-assisted transoral approach for the parapharyngeal space（PPS） tumors. Method:This retrospective study included 22 patients who were diagnosed with PPS tumors and treated with the endoscope-assisted transoral approach. Result:The postoperative pathological diagnosis included 10 cases of schwannoma, 7 cases of pleomorphic adenoma, 1 case of paraganglioma, 1 case of branchial cleft cyst, and 3 cases of malignant tumors for a diagnostic purpose. The surgical duration was between 15 minutes and 430 minutes（median duration 105 minutes）, and the intraoperative bleeding was between 10ml to 500ml（median bleeding 20 mL）. Complete resection with minor complication was performed in 21 cases, 1 case of recurrent schwannoma was done in an incomplete style because of intraoperative massive bleeding. With a 12-to-72-months follow up, there was no relapse on the 18 cases of benign tumor which were completely resected. Conclusion:Endoscope-assisted transoral resection provide cosmetic, micro-invasive and increased operative exposure to the PPS, especially for the benign tumors that medial to the carotid sheath. But is not recommend for relapsed cases and lesions that encompassing or lying posterolateral to the carotid sheath.

258. Exploring perioperative complications of anterior lumber interbody fusion in patients with a history of prior abdominal surgery: a retrospective cohort study

258. Exploring perioperative complications of anterior lumber interbody fusion in patients with a history of prior abdominal surgery: a retrospective cohort study

Impact of Intraoperative Hypothermia on Microsurgical Free Flap Reconstructions.

Patients requiring microsurgical defect reconstruction are highly susceptible to intraoperative hypothermia, given oftentimes long operative times and exposure of large skin surface areas. While the impact of hypothermia has been extensively studied across various surgical fields, its role in the setting of microsurgical free flap reconstruction remains elusive. This study evaluates the effects of hypothermia on outcomes of free flap reconstructions. Within 7 years, 602 patients underwent 668 microvascular free flap reconstructions. The cases were divided into two groups regarding the minimal core body temperature during free flap surgery: hypothermia (HT; < 36.0°C) versus normothermia (NT; ≥36.0°C). The data were retrospectively screened for patients' demographics, perioperative details, flap survival, surgical complications, and outcomes. Our data revealed no significant difference with regard to the rate of major and minor surgical complications, or the rate of revision surgery between both groups (p > 0.05). However, patients in the HT group showed significantly higher rates of total flap loss (6.6% [HT] vs. 3.0% [NT], p < 0.05) and arterial thrombosis (4.6% [HT] vs. 1.9% [NT], p < 0.05). This translated into a significantly longer hospitalization of patients with reduced core body temperature (HT: mean 16.8 days vs. NT: mean 15.1 days; p < 0.05). Hypothermia increases the risk for arterial thrombosis and total flap loss. While free flap transfer is feasible also in hypothermic patients, surgeons' awareness of core body temperature should increase. Taken together, we suggest that the mean intraoperative minimum temperature should range between 36 and 36.5°C during free flap surgery as a pragmatic guideline.

DONOR AND RECIPIENT OUTCOMES OF RETROPERITONEAL LAPAROSCOPIC DONOR NEPHRECTOMY IN OBESE VERSUS NON OBESE DONORS: A PROSPECTIVE STUDY

Objectives: The objective of the study was to establish the efficacy and safety of Retroperitoneal laparoscopic donor nephrectomy(RLDN) in obese donors. Although initially controversial, obese donors are now widely accepted for living kidney donation provided certain conditions are met. RLDN is considered difficult in obese donors because of abundant retroperitoneal fat. We performed a prospective non-randomised controlled study comparing early donor and recipientoutcomesof RLDN in obese and non-obese kidney donors. Methods: 200 donors underwent RLDN from June 2014 to April 2016,160 were non-obese (group I) and 40 were obese (group II). Preoperative parameters including Body Mass Index, age, gender, and operative parameters including total operative time, warm ischaemia time, and estimated blood loss were recorded. An additional surgical step in obese donors was the deliberate excision of excessive para-renal and peri-renal fat, allowing increased operative space and exposure of the kidney, hilum and ureter. Complications were compared using the Clavien-Dindo classification. Recipient s. creatinine at day 7,15 and 30 was compared between recipients who received grafts from obese and non-obese donors. Results and discussion: Operative time, warm ischaemia time, blood loss, length of hospital stay and complications were similar in the two groups in the two groups and there were no statistically significant differences. There were 17.5% right sided donors in group I and 15% in group II. S. creatinine in the recipients of grafts from the two groups of donors was similar. Our results suggest that transplant surgeons facile with retroperitoneal surgery may safely offer RLDN to obese donors with expectation of operative and post-operative parameters similar to those in non-obese donors. In addition similar recipient outcomes may be expected. The deliberate excision of retroperitoneal fat may be an additional step in this group of donors. Conclusions: Concerns about donor safety and recipient graft function after RLDN in obese donors may be allayed. RLDN is safe and efficacious in obese donors and gives all the benefits of minimal access surgery without compromising on recipient outcomes.

Retrospective analysis of pedicle screw accuracy for patients undergoing spinal surgery assisted by intraoperative computed tomography (CT) scanner AIRO® and BrainLab© navigation

Minimally invasive spine surgery techniques for pedicle screw instrumentation are being more frequently used. They offer shorter operative times, shorter hospital stays for patients, faster recovery, less blood loss, and less damage to surrounding tissues. However, they may rely heavily on fluoroscopic imaging, and confer radiation exposure to the surgeon and team members. Use of the AIRO Mobile Intraoperative CT by Brainlab during surgery is a way to eliminate radiation exposure to staff and may improve accuracy rates for pedicle screw instrumentation. We designed a retrospective analysis of our first 12 patients who had a total of 59 pedicle screws inserted when we began to incorporate the AIRO iCT scanner to our surgical workflow. During pedicle screw insertion, projection images were saved, and compared to CT scans gone at the end of the case. We measured the distances between the projected and postprocedural screw locations, at both the screw tips and tulip heads. We observed a mean of 2.8 mm difference between the projection and postprocedural images. None of the screws inserted had any clinically significant complications, and no patient required revision surgery. Overall, iCT guided navigation with the AIRO system is a safe adjunct to spinal surgery. It decreased operator and staff radiation exposure, and helped facilitate successful MIS surgery without fluoroscopic imaging. Additional studies and research can be done to further improve accuracy and reliability.

Clinical activity and outcomes during Geelong's general surgery response to the coronavirus disease 2019 pandemic.

The response to the coronavirus disease 2019 pandemic has required conserving capacity and resources to avoid the health sector being overwhelmed. This paper describes Geelong's general surgical response, surgical activity, outcomes and the effect on surgical training. Data collected from surgical audits; hospital databases and patient's medical records were used to compare the first 7 weeks of our new service delivery (30 March to 17 May 2020) to the corresponding 7 weeks in 2019 (1 April 2019 to 19 May 2019). All surgical cases, morbidity and mortality were discussed at weekly surgical audit meetings conducted by videoconference. Treatment performance indicators were tested by chi-squared test for proportions, and by Student's t-test or Mann-Whitney test for continuous variables. Elective general surgery decreased by 45.9% but an essential service was maintained by substantially increasing our public in private operating to perform 81 cases. Despite a 30% decrease in emergency department presentations, general surgery admissions decreased only 6.1% while emergency operations increased 13.9%. We used telehealth to conduct 81.3% of outpatient appointments and 61.8% of pre-operative anaesthetic reviews. No significant differences were found for overall surgical outcomes, including appendicectomy (perforation rates) and laparotomy (length of stay and morbidity). Operative exposure for trainees was maintained. Geelong was able to provide a safe and effective general surgery service during the first 7 weeks of the coronavirus disease 2019 pandemic. There are some valuable lessons which could be adopted elsewhere in the event of a surge or second wave of cases.

Cause for concern: Resident experience in operative trauma during general surgery residency at a Canadian centre.

BackgroundThe ability to provide competent operative trauma care is a core objective of general surgery training but recent publications question the ability of graduates to meet this standard. To assess the adequacy of operative trauma exposure during residency, we constructed and analyzed a retrospective trauma operative case log for general surgery residents at a Canadian trauma centre.MethodsThe Hamilton General Hospital Trauma Registry was used to identify all patients from July 2008 to June 2018 who underwent a trauma operation on the neck, chest, or abdomen. Medical records were reviewed to determine procedure type and resident presence.ResultsIn our study, 417 patients underwent 570 operations (422 abdominal, 103 thoracic, and 45 neck). For the 35 residents that completed their general surgery residency during the study, the median number of trauma laparotomies was 5, with only 14/35 (40%) present for ≥10 trauma operations. Only 10 residents (29%) were exposed to a neck exploration and 18 (51%) exposed to a thoracic operation for trauma.ConclusionsOperative trauma exposure amongst general surgery residents at an academic Canadian trauma centre was limited. Cumulative operative trauma surgery exposure of a typical graduating resident was inadequate when compared to Canadian and American accrediting-body standards.

COVID-19 and surgery: A thematic analysis of unintended consequences on performance, practice and surgical training

PurposeThe shift in the national focus and allocation of resources to the management of COVID19 has led to significant changes to surgical practice including the delay of elective surgery. The aim of this study was to explore the implications of such changes on surgeons. MethodUsing a qualitative study design, semi-structured interviews were conducted with general surgery consultants and non-consultant hospital doctors from a major tertiary hospital in the Dublin region between March–May 2020. Data collection proceeded iteratively using a thematic analysis approach with quality controls such as memoing and collaborative analysis. ResultsFourteen surgeons (8 male, 6 female) were interviewed. The majority (n = 11, 78.6%) were NCHDs. Significant themes determined included ‘impacts’ on a variety of constructs such as performance, self-reported fatigue and wellbeing. Training themes elucidated included the effects of the cancellation of elective admissions on reduced operative exposure for trainees. Senior surgical staff were particularly focused on increased complexity in patient management. New policy requirements such as personal protective equipment use and novel rotas have had implications for aspects of work engagement. The pandemic and subsequent national restrictions imposed has afforded opportunities for improved well-being but also resulted in greater solitude in surgeons. ConclusionsRhetoric surrounding fatigue management and virus control dominates the conversation on the relationship between COVID-19 and surgery. Tipping the balance back to parity of fatigue management with service delivery in surgery will be key for sustainability of the surgical workforce.

Operator and Potential Exposure to Hydrogen Sulfide: A Study of the British Columbia Dairy Industry

ABSTRACT Hydrogen Sulfide (H2S) is produced in manure storage facilities and released during manure agitation. Exposure to this gas presents health risks to workers at daily exposure of greater than 10 parts per million (ppm). Exposure levels on BC dairy farms are unknown. The aim of this study was to document peak H2S exposure levels to operators and bystanders during manure agitation on British Columbia dairy farms to determine if action levels were exceeded. Farms were evaluated at two time points during manure agitation. Both operator exposure and potential exposure sampling were undertaken. Peak hydrogen sulfide levels were measured and categorized as greater than or less than the ceiling level (10 ppm) and action level (5 ppm). Associations between H2S levels above the ceiling level and farm factors were assessed. Measures were recorded at 43 dairy farms with 91 total measures recorded. Action levels were exceeded in 30% of operator measures and 64% of potential exposure measures while 20% of operator and 53% of potential peak H2S measures exceeded 10 ppm. Manure storage facilities were evenly distributed between indoor and outdoor locations with under-barn (43%) and outdoor storage (47%) most common. Sawdust was the most prominent bedding type (65%). Tractor operated propeller was the most common type of agitation equipment (62%). Manure temperature remained a significant predictor in the multivariate model for operator peak exposure. Exposure to H2S above the action level commonly occurs on BC Dairy farms. Given that Worksafe BC requires exposure control plans for H2S levels above 5 ppm, and that on dairy farms, measures of operator and potential H2S exposures were recorded above these levels, best practices to reduce potential H2S exposure are necessary to reduce possible operator and bystander exposure.

Letter: Emergency Response Plan During the COVID-19 Pandemic: The University of Alabama at Birmingham Experience.

Letter: Emergency Response Plan During the COVID-19 Pandemic: The University of Alabama at Birmingham Experience.

A COMPARISON OF CONTEMPORARY PORTABLE X-RAY SYSTEMS

<h3>Background</h3> There is substantial evidence for a cumulative dose-related response to ionizing radiation in the form of cancer development years after initial exposure. Therefore, this study focused on effective dose (E), a quantity with direct correlations to biologic risk from dental x-ray exposures. <h3>Objectives</h3> The purpose of this study was to measure doses and calculate (E) from adult full-mouth examinations (FMXs) by using handheld and conventional wall-mounted x-ray sources with both circular and rectangular collimation (RC). <h3>Materials and Methods</h3> A human tissue-equivalent phantom and optically stimulated luminescent dosimeters were used to measure dose from simulated FMXs (n = 18) at 24 head/neck tissue sites. The parameters were 70 kV/7 mA (0.84 mAs and 1.34 mAs) for Conventional Circular and RC handheld device; 60 kV/2.5 mA (2.16 mAs) for NOMAD Circular and RC handheld device; and 60 kV/2.0 mA (1.98 mAs) for Xray2 Go Circular (XTG) handheld device. Analysis of variance (ANOVA) and Tukey's HSD ("honest significant difference") statistics demonstrated significant relationships. <h3>Results</h3> The FMX E (µSv) values were: NOMAD RC (6.9); XTG (16.7); NOMAD Circular (17.4); and Conventional Circular (26.3). For circular techniques, the handheld device E was significantly lower than the conventional unit for both devices (<i>P</i> < .0001). With RC, E was significantly lower than all circular techniques (<i>P</i> < .0001). Significant differences in E were found for all modality combinations except NOMAD Circular and XTG (<i>P</i> = .8329). Operator groin exposure was significantly higher (60%–90%) than thyroid, chest, and trigger hand exposures, which were indistinguishable from ambient background levels, for all handheld modalities (<i>P</i> < .0001). <h3>Discussion</h3> Handheld device E was at least 34% less than conventional circular and as much as 74% less with the use of RC. Operator exposure to the groin can increase significantly from overangulating the handheld sources; however, the addition of RC can reduce this exposure by as much as 76%.