Tag: surgery

Categories : HospitalsTags :

Slight Safety Edge for Ringer’s Lactate over Standard Saline

On By ModernMedia
Intravenous IV drip
Source: Marcelo Leal on Unsplash

A new US study has found that Ringer’s lactate may be a better and safer treatment option for emergency department and hospital patients than saline solution, especially in sepsis.

According to the study of nearly 150 000 hospital patients, which was published in JAMA Network Open, Intermountain Healthcare researchers found that patients who received Ringer’s lactate solution instead of normal saline for IV fluids had a lower risk of kidney injury and death than when they were given saline.

Saline solution has long been the standard for IV solution with more than 200 million litres administered to hospital patients annually in the US.

Intermountain researchers found that patients who were given Ringer’s lactate as an alternative to saline solution had a 2.2% reduced risk of kidney injury and death.

Joseph Bledsoe MD, principal investigator of the study, said: “That might not sound like a big difference but considering how many patients receive IV fluids every day, it could lead to a major improvement in health outcomes. For our health system alone, that’s 3000 people every year who may avoid complications from normal saline, at no additional cost.”

For this large-scale, study researchers encouraged clinicians, through education and electronic order entry alerts, to use Ringer’s lactate solution rather than saline solution for IV fluid treatment.

Saline solution is a combination of sodium chloride and water at a concentration of 9g of salt per litre (0.9%) which are levels higher than blood, commonly called normal saline.

Mounting evidence points to intravenous normal saline solution increasing the risk of metabolic acidosis, acute kidney injury, and death. This could be due to normal saline having higher levels of chloride and being slightly more acidic than fluids in the human body.

Though they have different ingredients, both Ringer’s lactate and normal saline are used for replacing fluids and electrolytes in hospital patients who have low blood volume or low blood pressure.

Ringer’s lactate contains electrolytes more similar to blood plasma than saline solution. Ringer’s lactate, which is a type of balanced crystalloid, is also much closer to human fluid pH and did not show the same related risk of kidney injury, in line with previous smaller studies.

The study included 148 423 adult patients admitted to the emergency department or inpatient units at 22 Intermountain Healthcare hospitals in Utah and Idaho between November 1, 2018, and February 29, 2020.

At 30 days post treatment, researchers found a 2.2% reduction in major adverse kidney events, including persistent kidney dysfunction, new initiation of dialysis, and death in patients who were given Ringer’s lactate rather than normal saline solution during their emergency department or hospital treatment course.

The impact was even greater on patients with sepsis and on patients who received more fluids as part of their treatment. Not all patients benefit from Ringer’s lactate – patients with brain injury may still benefit from normal saline, but further studies are needed.

Researchers determined that before the study, approximately 25% of patients received Ringer’s lactate, and 75% received normal saline solution. Afterward, the percentages flipped to 25% receiving normal saline and 75% Ringer’s lactate.

Researchers found that nudges in the Intermountain electronic order system were more effective in changing clinician habits than relying on education.

“Given the success of nudges in making this change, our success could be replicated in other health systems and allows for sustained improvement,” said Dr. Bledsoe. “Given the scope of this study, and its success in addition to previous studies, hospitals around the country should consider what they use for IV fluids, too.”

In an editorial about these findings published in the same issue of JAMA Network Open, Matthew W. Semler, MD, MSc, assistant professor of medicine at Vanderbilt University Medical Center, wrote that the study “raises important questions about the choice between Ringer’s lactate solution and saline and, more broadly, how we should make evidence-based choices between widely available, commonly used treatment alternatives in acute care.”

Source: News-Medical.Net

Categories : HospitalsTags :

Aggressive Warming during Surgery Does not Reduce Complications

On By ModernMedia
Photo by Anna Shvets on Pexels

When patients kept at a body temperature of 37C with aggressive warming during surgery, there was no reduction cardiac complications compared to patients kept at 35.5C, finds a large new study reported in The Lancet. No differences was seen in number of infections or required blood transfusions in patients kept at cooler body temperatures.

An unintentional drop in body temperature is a normal side effect during surgery, due mostly to anaesthetic medications’ interference with the body’s temperature regulation processes. In Western countries, nursing staff typically use forced-air heaters to keep patients warm during surgery, with a target temperature of 36C. This trial, one of the largest to date, sought to determine whether even greater warming, to 37C, would reduce the risk of cardiac complications, a major cause of mortality in the first 30 days after surgery.

Results showed no significant differences between groups for the trial’s primary endpoint, a composite of troponin elevation due to ischemia (an indicator of heart injury), non-fatal cardiac arrest or death from any cause within 30 days after surgery. Researchers also reported no differences for any of the trial’s secondary endpoints.

“This trial tells us that there is no benefit to aggressively warming patients to 37 C during surgery. It is simply unnecessary, and it doesn’t improve any substantive outcomes,” said Daniel I. Sessler, MD, Michael Cudahy professor and chair of the Department of Outcomes Research at Cleveland Clinic and the trial’s lead author. “Also, the results show that 36C should not be considered the threshold for defining mild hypothermia since there was no harm at 35.5C.”

The researchers enrolled 5050 patients, mostly in Chinese centres. Participants had various major noncardiac surgical procedures, with a minimum duration of two hours and an average duration of four hours. Half of the patients were randomised to routine care, with a target body temperature of 35.5C, and the other half randomised to aggressive warming, with a target body temperature of 37C.

For patients assigned to routine care, nursing staff put a warming cover in position but did not activate it until the patient’s body temperature decreased to less than 35.5C, resulting in an average group body temperature of 35.6C. With the more aggressive warming protocol, nurses covered patients with a heated blanket for 30 minutes before surgery and then used two forced-air heaters to keep patients warmed to a mean of 37.1 C during surgery.

In addition to seeing no benefit in terms of the composite primary endpoint, the trial reported no significant differences between groups in terms of serious wound infections, length of hospitalization, hospital re-admissions or the need for blood transfusions. The investigators were surprised that rates of wound infections and transfusions were similar to previous studies, which suggested that both were more common in patients maintained at lower body temperatures.

While most patients were enrolled in China, Dr Sessler said, the results should still be generalisable to patients and health care settings in other countries.

“This study shows that it is reasonable to keep patients warm, but we saw no evidence whatsoever that it makes a difference if they’re just above or just below 36C,” Dr Sessler said. “Surgical patients should still be warmed, but there’s no need to be super-aggressive about the warming.”

Less serious or non-medical outcomes, such as patient comfort or shivering was not assessed. Dr Sessler said that patients maintained at a lower body temperature may shiver or feel cold after surgery, but both are temporary and unlikely to have a meaningful health impact.

Source: American College of Cardiology

Categories : Paediatrics Pain ManagementTags :

Fall in Paediatric Post-surgical Opioid Prescriptions

On By ModernMedia
Children
Photo by Ben Wicks on Unsplash

A large study has shown that opioid prescriptions for children who underwent one of eight common outpatient surgeries declined over a period of five years. These findings, reported in the journal Pediatrics, suggest that clinicians are using more discretion when considering which paediatric patients require an opioid prescription after their procedures.

Opioids are routinely prescribed after a surgery to help paediatric patients manage mild or moderate pain. However, recent studies have suggested that recovery is similar with limited or no opioid use. Additionally, opioids prescribed to children can result in respiratory depression, which causes carbon dioxide to not be expelled from the lungs properly, and the continued use of those opioids, after acute pain has resolved. Despite these findings, no prior studies had looked at recent data on national opioid trends for surgery in children in the context of whether there has been any shift away from prescribing opioids more broadly.

“Children grow throughout their childhood, and because opioids are often prescribed based on weight, we cannot assume that what is appropriate for a 5-year-old could also apply to an adolescent,” said the study’s lead author Tori N. Sutherland, MD, MPH. “In our study, we wanted to be responsible with our data and consider surgical distribution by age group.”

In this study, the researchers used data from a private insurance database to study opioid-naïve patients under the age of 18 who underwent one of eight surgical procedures between 2014 and 2019. The procedures ranged from tonsillectomies to knee surgery. The primary outcome of the study was whether a prescription for opioids was filled within 7 days of surgery, and the secondary outcome was the total amount of opioid dispensed. A total of 124 249 patients were included in the study. Patients were separated by age into adolescents, school-aged children and preschool-aged children.

The researchers found that the percentage of children who had an opioid prescription filled after their surgery fell across all three age categories. For adolescents, prescriptions dropped from 78.2% to 48%; for school-aged children, from 53.9% to 25.5%; and for preschool-aged children, from 30.4% to 11.5%. Additionally, the average morphine milligram equivalent dispensed declined by approximately 50% across all three age groups.

The researchers also found that there was a steeper decline in opioid prescriptions beginning in late 2017, first in the adolescent group and then followed by school- and preschool-aged children. This trend appeared to represent a ‘trickle down’ effect, but more research is needed to explore the difference in trends by age group.

“Our findings demonstrate that pain treatment for children and adolescents undergoing surgery has changed dramatically over the past 5 years,” said Mark Neuman, MD, senior author. “Understanding what these trends mean for patient experiences and health outcomes is a key next step.”

Source: EurekAlert!

Categories : AgeingTags :

Factors that Affect Disability after Surgery in Older Adults

On By ModernMedia
old man walking with canes
Source: Miika Luotio on Unsplash

In an analysis of older adults who underwent surgery, published in the Journal of the American Geriatrics Society, more who had non-elective surgery were found to experience disabilities than those who had elective surgery, and factors such as age increased this vulnerability.

The study included 247 adults aged 70 years or older who were discharged from the hospital after major surgery from 1997 to 2017, patients who had non-elective surgery had more disabilities in daily activities over the following 6 months than those who had elective surgery.  

Researchers identified 10 factors that were associated with greater disability burden: age 85 years or older, female sex, Black race or Hispanic ethnicity, neighbourhood disadvantage, multimorbidity, frailty, one or more disabilities, low functional self-efficacy, smoking, and obesity. The burden of disability increased with each additional “vulnerability” factor.

“The results from this study can be used by clinicians to identify older adults who are particularly susceptible to poor functional outcomes after major surgery, and a subset of the factors identified could serve as the basis for new interventions to improve functional outcomes in vulnerable older surgical patients,” said lead author Thomas M. Gill, MD, of the Yale School of Medicine.

Source: Wiley

Categories : Surgeries & ProceduresTags :

Smartphone Pics of Post-surgical Wounds for Spotting Infections

On By ModernMedia
Photo by Daniel Romero on Unsplash

Researchers have shown that smartphone pictures of post-surgical wounds taken by patients and then assessed by clinicians help spot infections early on.

These ‘surgery selfies’ were associated with a reduced number of GP visits and improved access to advice among patients who took them. This practice could help manage surgical patients’ care while they recover.

Death within 30 days of surgery is the third largest cause of mortality globally. More than a third of postoperative deaths are associated with surgical wound infections.

In the study, published in NPJ Digital Medicine, University of Edinburgh researchers conducted a randomised clinical trial involving 492 emergency abdominal surgery patients to determine if photos from smartphones and questions on symptoms of infection could be used to diagnose wound infections early.

One group of 223 patients were contacted on days three, seven and 15 after surgery and directed to an online survey, where they were asked about their wound and any symptoms they were experiencing. Then they were asked to take a picture of their wound and upload it.

A surgical team member assessed the photographs and patients’ responses were assessed for signs of wound infection. They followed up with patients 30 days after surgery to find out if they had been subsequently diagnosed with an infection.

A second group of 269 received standard care and were contacted 30 days after surgery to find out if they had been diagnosed with an infection.

No significant difference between groups was seen in the overall time it took to diagnose wound infections in the 30-days after surgery.

However, the smartphone group was nearly four times more likely to have their wound infection diagnosed within seven days of their surgery compared to the routine care group. They also had fewer GP visits and reported a better experience of trying to access post-operative care.

The research team is now conducting a follow-up study to determine how this can be best put into practice for surgical patients around the country. Artificial intelligence will also be used to help the clinical team in assessing the possibility of wound infection.

Professor Ewen Harrison, Professor of Surgery and Data Science, who led the research said: “Our study shows the benefits of using mobile technology for follow-up after surgery. Recovery can be an anxious time for everybody. These approaches provide reassurance – after all, most of us don’t know what a normally healing wound looks like a few weeks after surgery. We hope that picking up wound problems early can result in treatments that limit complications.”

Dr. Kenneth McLean, who co-led the research said: “Since the COVID-19 pandemic started, there have been big changes in how care after surgery is delivered. Patients and staff have become used to having remote consultations, and we’ve shown we can effectively and safely monitor wounds after surgery while patients recover at home – this is likely to become the new normal.”

Source: University of Edinburgh

Categories : Pain ManagementTags :

Fifth of Opioid-Naïve Patients Continue Use Post-surgery

On By ModernMedia
Photo by Myriam Zilles on Unsplash

More than a fifth of ‘opioid-naïve’ patients continue to use opioids three months after having a procedure, underscoring the often-overlooked role surgery plays in the opioid epidemic.

In research presented at the ANESTHESIOLOGY® 2021 annual meeting, smokers and people with bipolar disorder, depression or pulmonary hypertension were found to be at highest risk.

Persistent opioid use was much higher than expected among opioid-naïve patients (those who did not have an opioid prescription filled in the previous year). Surgery is the first time many patients have used opioids, often prescribed for post-surgical pain management.

The study examined data on 13 970 opioid-naïve adults from 2013-2019. In the study, opioid-naïve patients were those who had not filled an opioid prescription 31 days to one year before surgery (patients often are prescribed opioids in advance so they are available immediately after the surgery). Researchers found that 21.2% of patients refilled their opioid prescription three months to one year after the procedure. Unless they have cancer or had chronic pain before surgery, very few patients should still need opioids three months after surgery, the researchers note.

Analysing 46 potential risk factors, researchers found many patients were still using opioids after three months. The top four risk-factors identified, which were modifiable, were: smoking, bipolar disorder, depression and pulmonary hypertension. They also found that procedures with cardiac and podiatry surgical providers and patients who had cataract surgery were at an increased risk of persistent opioid use.

“To reduce the likelihood of ongoing opioid use, physician anesthesiologists should use the preoperative assessment to identify patients at highest risk for persistent use,” said lead author Gia Pittet, AuD, PhD, visiting graduate researcher for anesthesiology and perioperative medicine at the University of California, Los Angeles. “Before they have surgery, patients who smoke should be encouraged to quit, those with pulmonary hypertension should see a doctor to help them get the condition under control and patients with bipolar disorder or depression may require a preoperative adjustment of their medications.”

Patients should also receive counseling about the safe use of opioids and be offered alternative pain management, such as limited or non-opioid multimodal treatment and be monitored frequently and closely while they are taking opioids.

Source: American Society of Anesthesiologists

Categories : Medical Research & TechnologyTags :

A Leak-proof, Biocompatible Intestinal Patch

On By ModernMedia

Researchers at Empa have developed a patch that stably seals two sutured pieces of intestine and thus prevents dangerous leaks.

A burst appendix or a life-threatening intestinal volvulus are emergencies that need to be treated by surgeons immediately. However, operations carry risks: highly acidic digestive juices and intestinal bacteria can leak out, causing peritonitis and sepsis.

Sealing sutured tissue with a plaster has already been tried, but the first were not well tolerated or were even toxic. Currently, these plasters are made of biodegradable proteins, which have variable clinical results. These is because they are mainly intended to support the healing process, and dissolve too quickly when in contact with digestive juices and don’t always hold tight. “Leaks after abdominal surgery are still one of the most feared complications today,” explained Empa researcher Inge Herrmann, who is also professor for nanoparticulate systems at ETH Zurich.

Searching for a material that could reliably seal intestinal injuries and surgical wounds, Hermann’s team found a synthetic composite material made up of four acrylic substances that, together, form a chemically stable hydrogel. Additionally, the patch actively cross-links with the intestinal tissue until it is fluid-tight. The quadriga of acrylic acid, methyl acylate, acrylamide and bis-acrylamide works in perfect synergy, as each component conveys a specific feature to the final product: a stable bond to the mucosa, the formation of networks, resistance to digestive juices and hydrophobicity. This new technology is detailed in Advanced Functional Materials.

In lab experiments, the researchers found the polymer system met their expectations. “Adhesion is up to ten times higher than with conventional adhesive materials,” said researcher Alexandre Anthis from Empa’s Particles-Biology Interactions lab in St. Gallen. “Further analysis also showed that our hydrogel can withstand five times the maximum pressure load in the intestine.” The material’s design uses its tailored effect: The rubbery composite selectively reacts with digestive juices that might leak through intestinal wounds, expands and closes all the more tightly. The inexpensive, biocompatible super glue, could thus shorten hospital stays and save healthcare costs, and Anthis is making plans to bring it to market.

Source: Empa

Categories : Hospitals Medical Research & TechnologyTags :

New Medical Device Slashes Surgery Risk

On By ModernMedia
Source: Pixabay CC0

A new electromedical device provides important data about possible cardiovascular and pulmonary risks before an operation.

Before any operation, it is important to properly assess the individual risk: Are there perhaps circulatory or pulmonary problems that need special consideration? To what extent can special risks be taken into account when planning the anaesthesia? Previously, clinicians have had to rely on rather subjective empirical values or carry out more elaborate examinations when in doubt. To address this, a novel device has been developed by TU Wien and MedUni Wien to objectively measure the cardiovascular and pulmonary system fitness of patients.

Pre-op interviews are important—but subjective
Complications often occur after surgical interventions. In addition to blood loss and sepsis, perioperative cardiovascular and pulmonary problems are among the most common causes of death in the first 30 days after surgery.

To minimise this risk, anesthesiologists routinely talk to patients before surgery, in addition to measuring their blood pressure, performing an electrocardiogram, or conducting more laborious examinations. But assessing responses can be highly individualised. “There are also objectively measurable parameters by which one could easily identify possible risks,” said Prof Eugenijus Kaniusas (TU Wien, Faculty of Electrical Engineering and Information Technology). “So far, however, they have not been routinely measured.”

Just hold your breath
This new device uses multiple sensors to determine key metrics in a completely non-invasive way. All the patient has to do is hold their breath for a short time to slightly outbalance their body, which responds reflexively with various biosignals. “Holding your breath is a mild stress for the body, but that is already enough to observe changes in the regulatory cardiovascular and pulmonary systems,” explained Eugenijus Kaniusas. “Oxygen saturation in the blood, heart rate variability, certain characteristics of the pulse waveform—these are dynamic parameters that we can measure in a simple way, and from them we could ideally infer individual fitness in general, especially before surgery.”

Since the device is non-invasive, medical training is not needed to operate it, and has no side effects. The result is easy to read: A rough assessment according to the three-color traffic light system or a score between 0 and 100 is displayed. The measurement can also be carried out at the bedside without any problems for people with limited mobility.

“Our laboratory prototype is being tested at MedUni Wien in cooperation with Prof. Klaus Klein from the University Department of Anesthesia, General Intensive Care Medicine and Pain Therapy. We hope to bring the device to market in the next 5 years with the help of research and transfer support,” said Eugenijus Kaniusas.

Source: Vienna University of Technology

Categories : Cancer HospitalsTags :

Cancer Surgery Patients Have a Reduced Hospital Stay with ‘Prehabilitation’

On By ModernMedia
Photo by Martha Dominguez de Gouveia on Unsplash


A new approach to improve their fitness for surgery reduced the length of hospital stay for cancer patients, according to a new study.

Termed ‘prehabilitation’, the study’s approach includes exercise, nutrition and psychological and social interventions to bolster physical and mental health before surgery.

The study, published in the Annals of Surgery, found that prehabilitation interventions of between one and four weeks reduced cancer patients’ stay in hospital by 1.8 days compared with usual care.

Study author Dr Chris Gaffney from Lancaster Medical School said: “Surgery is like a marathon in terms of stressing the body, and you wouldn’t run a marathon without training.”

The researchers found that as little as one week can still benefit patient outcomes, indicating that prehabilitation should be recommended to accelerate recovery from cancer surgery, as shown by a reduced hospital length of stay.

Study author Dr Joel Lambert, now a postgraduate student at Lancaster Medical School and a surgeon at East Lancashire Teaching Hospitals NHS Trust, said: “We think that it may also confer a survival advantage for cancer patients as they can get to follow up treatments like chemotherapy more quickly.

“We think that the patient groups most likely to benefit are the ones with lower levels of fitness at baseline. In the Northwest we have some of the most socioeconomically deprived populations in the UK. This subset tend to have more co-morbid conditions hence less fit.”  

The patients studied were those with liver, colorectal, and upper gastrointestinal cancer, and who are often less fit than other cancer patients.

The study interventions were grouped into three types

  • Multimodal prehabilitation: exercise, which included both nutrition and psychosocial support,
  • Bimodal prehabilitation: exercise and nutrition or psychosocial support
  • Unimodal prehabilitation: exercise or nutrition alone

The exercise interventions included aerobic, resistance, and both aerobic and resistance exercises at all levels of intensity, some supervised by a kinesiologist or physiotherapist, while others were home-based exercise regimes. These ranged from one to four weeks and all interventions were within the current NHS surgery targets for cancer surgery.

The researchers concluded: “Future studies should focus on identifying patients who would benefit most from prehabilitation and the mechanistic underpinning of any improvement in clinical outcomes. Studies should closely monitor nutrition intake to determine if the response to exercise prehabilitation is dependent upon nutritional status. Lastly, mortality should be monitored for 12 months post surgery to determine if prehabilitation has any effect beyond 30 or 90 days.”

Source: Lancaster University

Categories : HospitalsTags :

Sleep Deprivation Common in Surgeons, Impacting Performance

On By ModernMedia
Photo by Mulyadi on Unsplash

New research has found that surgeons were sleep deprived prior to on-call shifts and afterwards even more so, and crucially, that sleep deprivation impacted surgical performance. 

The study is the first to focus on Irish surgeons and is published in the Journal of Surgical Research. A separate study found that short naps of 30 to 60 minutes do little to reduce sleep deprivation.

Focussing on the effects of being ‘on-call’, a frequent state for surgeons, the study explored subjective and objective metrics around sleep and performance using ‘on-call’ as a particular influencer for increased fatigue.

Surgeons frequently work 24 straight hours (or more) resulting in unavoidable sleep disturbance. This is partly due to historical associations of the Halstedian Era of Surgery to ‘reside’ in the hospital in order to properly learn, but also current staffing levels mandating surgeons to complete regular on-call work.

Participants were hooked up to electroencephalogram (EEG) machines and a validated modified Multiple Sleep Latency Test testing was used to objectively measure sleep on the morning of their on-call shift. The researchers also record other validated tests for subjective sleep and fatigue measurement. ‘Sleep latency’ refers to the time it takes to go from being fully awake to sleeping and is often an indicator of sleepiness. The surgeons in the study had early onset sleep latency before on-call, which was exacerbated further in post-call settings.

Performance was measured with standardised and validated tools. Technical performance of surgeons was assessed using the validated Simendo © surgical simulator, while cognitive performance was measured using the Psychomotor Vigilance Task (PVT) to assess objective alertness and reaction time, a known aspect of cognitive performance.

The study is the first to attempt to control for a series of confounding variables such as experience, quality and quantity of sleep, the influence of caffeine and circadian rhythm influences.

The study found that:

  • Surgeons had poor baseline sleep quality and were objectively sleep-deprived, even pre-call, when they should be in a ‘rested state’.
  • In all study participants, early onset sleep latency was seen in pre-call settings and worsened in post-call settings.
  • Early onset sleep latency was worse in trainees compared to consultants, though both groups experienced early onset sleep latency post-call.
  • As sleep-deprivation increased, diminished performance was seen in cognitive tasks and surgical tasks with greater cognitive components.
  • Higher levels of self-reported fatigue and daytime sleepiness were recorded post-call.

Technical skill performance was relatively preserved in acutely sleep deprived states but may be influenced by learning curve effects and experience in surgical tasks.

Existing models of surgical on-call were not conducive to optimising sleep for surgeons, the research found. But making changes for better sleep has challenges, such as loss of continuity of patient care, loss of trainee exposure, and reduced service delivery.

Dale Whelehan, PhD researcher in Behaviour Science at the School of Medicine and lead researcher commented: “The findings of this study tell us that current provision of on-call models preclude the opportunity for surgeons to get enough rest. Similarly, surgeons are sleep deprived before going on-call which further perpetuates the issue. The implications for performance suggest aspects of surgeons performance is diminished, particularly tasks which might be more cognitively demanding. 

“We need meaningful engagement from all stakeholders in the process, working towards the common goal of optimising performance in surgeons. This involves looking at the multifactorial causes and effects of fatigue. Part of that discussion involves consideration around how current models of on-call influence sleep levels in healthcare staff, and how it creates barriers to fatigue management in staff.”

Professor Paul Ridgway, Department of Surgery at Trinity, who supervised the study, said: “Our study is further evidence that the way we deliver emergency work alongside normal work in Ireland has to change. We need to learn from our colleagues in aviation who have mandatory rest periods before flights.”

Source: Trinity College Dublin