Effect of tidal volume on gas exchange during rescue ventilation.

Tidal volume VT required for mouth-to-mouth (MTM) and bag-valve-mask (BVM) rescue ventilation remains debatable owing to differences in physiology and end-point objectives. Analysis of gas transport may clarify minimum necessary VT and its determinants. Alveolar and arterial O2 and CO2 responses to MTM and air BVM ventilation for VT between 0.4 and 1.2 liters were computed using a model of gas exchange that incorporates inspired gas concentrations, airway dead space, cardiac output, pulmonary shunt, blood gas dissociation curves, tissue compartments, and metabolic rate. Parameters were adjusted to match published human data. Steady state arterial oxygen saturation reached plateaus at VT above 0.7 liters with MTM and 0.6 liters with air ventilation at 12 breaths per minute. Increasing shunt shifted oxygenation plateaus downward, but larger tidal volumes did not improve oxygen saturation. Carbon dioxide retention occurred at VT below 2.3 liters for MTM ventilation and 0.6 liters for air ventilation. Results establish a physiological foundation for tidal volume requirements during resuscitation.

Patient-specific predictors of failure to rescue after pancreaticoduodenectomy.

BACKGROUND: Failure to rescue (FTR) is a recently described outcome metric for quality of care. However, predictors of FTR have not been adequately investigated, particularly after pancreaticoduodenectomy. We aim to identify predictors of FTR after pancreaticoduodenectomy. METHODS: We reviewed all patients who developed serious morbidity after pancreaticoduodenectomy from 2005 to 2012 in the ACS-NSQIP database. Logistic regression was used to identify preoperative and postoperative risks for 30-day mortality within a development cohort (randomly selected 80%). A score was created using weighted beta coefficients. Predictive accuracy was assessed on the validation cohort (remaining 20%) using a receiver operator characteristic curve and calculating the area under the curve (AUC). RESULTS: The FTR rate was 7.2% after pancreaticoduodenectomy (n = 5,027). We identified 5 independent risk factors: age ≥65 and albumin ≤3.5 g/dL, preoperatively; and development of shock, renal failure, and reintubation, postoperatively. The generated score had an AUC = 0.83 (95% CI, 0.77-0.89) in the validation cohort. Using the score: 1*Albumin ≤3.5 g/dL + 2*Age ≥ 65 + 2*Shock + 5*Renal failure + 5*Reintubation, FTR rates increased with increasing score (p < 0.001). CONCLUSION: FTR rates have previously been shown to be associated with hospital factors. We show that FTR is also associated with preoperative and postoperative patient-specific factors.

WHipple-ABACUS, a simple, validated risk score for 30-day mortality after pancreaticoduodenectomy developed using the ACS-NSQIP database.

BACKGROUND: Pancreaticoduodenectomy needs simple, validated risk models to better identify 30-day mortality. The goal of this study is to develop a simple risk score to predict 30-day mortality after pancreaticoduodenectomy. METHODS: We reviewed cases of pancreaticoduodenectomy from 2005-2012 in the American College of Surgeons-National Surgical Quality Improvement Program databases. Logistic regression was used to identify preoperative risk factors for morbidity and mortality from a development cohort. Scores were created using weighted beta coefficients, and predictive accuracy was assessed on the validation cohort using receiver operator characteristic curves and measuring area under the curve. RESULTS: The 30-day mortality rate was 2.7% for patients who underwent pancreaticoduodenectomy (n = 14,993). We identified 8 independent risk factors. The score created from weighted beta coefficients had an area under the curve of 0.71 (95% confidence interval, 0.66-0.77) on the validation cohort. Using the score WHipple-ABACUS (hypertension With medication + History of cardiac surgery + Age >62 + 2 × Bleeding disorder + Albumin <3.5 g/dL + 2 × disseminated Cancer + 2 × Use of steroids + 2 × Systemic inflammatory response syndrome), mortality rates increase with increasing score (P < .001). CONCLUSION: While other risk scores exist for 30-day mortality after pancreaticoduodenectomy, we present a simple, validated score developed using exclusively preoperative predictors surgeons could use to identify patients at risk for this procedure.

The use of collaboration to implement evidence-based safe practices.

The Pennsylvania Patient Safety Authority receives over 235,000 reports of medical error per year. Near miss and serious event reports of common and interesting problems are analysed to identify best practices for preventing harmful errors. Dissemination of this evidence-based information in the peer-reviewed Pennsylvania Patient Safety Advisory and presentations to medical staffs are not sufficient for adoption of best practices. Adoption of best practices has required working with institutions to identify local barriers to and incentives for adopting best practices and redesigning the delivery system to make desired behaviour easy and undesirable behaviour more difficult. Collaborations, where institutions can learn from the experiences of others, have show decreases in harmful events. The Pennsylvania Program to Prevent Wrong-Site Surgery is used as an example. Two collaborations to prevent wrong-site surgery have been completed, one with 30 institutions in eastern Pennsylvania and one with 19 in western Pennsylvania. The first collaboration achieved a 73% decrease in the rolling average of wrong-site events over 18 months. The second collaboration experienced no wrong-site operating room procedures over more than one year. Significance for public healthSince the Institute of Medicine's To Err is Human identified medical errors as a major cause of death, the public has been interested in the recommendations for reporting of medical errors and implementing safe systems for the delivery of healthcare. The Commonwealth of Pennsylvania has followed those recommendations and found that an essential intermediate step between analysing reports and implementing safe systems is collaborative learning among healthcare institutions. The experience in Pennsylvania should be useful to other public organizations wishing to improve safety.

Establishing a global learning community for incident-reporting systems.

BACKGROUND: Incident-reporting systems (IRS) collect snapshots of hazards, mistakes and system failures occurring in healthcare. These data repositories are a cornerstone of patient safety improvement. Compared with systems in other high-risk industries, healthcare IRS are fragmented and isolated, and have not established best practices for implementation and utilisation. DISCUSSION: Patient safety experts from eight countries convened in 2008 to establish a global community to advance the science of learning from mistakes. This convenience sample of experts all had experience managing large incident-reporting systems. This article offers guidance through a presentation of expert discussions about methods to identify, analyse and prioritise incidents, mitigate hazards and evaluate risk reduction.

Wrong site surgery near misses and actual occurrences.

Under coordination by the Patient Safety Authority, staff members in facilities across Pennsylvania analyzed 97 wrong site surgery near misses and 44 actual occurrences using a common analysis form from August 2007 to August 2008. These assessments were aggregated and compared by the Patient Safety Authority. Assessments in which near misses were identified that did not advance to actual wrong site occurrences were significantly more likely to report compliance with patient identification and preoperative reconciliation protocols, accurate scheduling, notation of the surgical site on the consent form, participation of the surgeon in preoperative verification, participation of all surgical team members in the time out, time outs performed with the site marking visible after draping, and the surgeon explicitly empowering team members to speak up if concerned and acknowledging concerns when expressed.

Lung compression effects on gas exchange in human breath-hold diving.

Lung compression during breath-hold diving reduces gas exchanging surface area. Beyond a critical depth, collapse of all alveoli should result in total pulmonary shunt and a drop in arterial oxygen partial pressure toward the mixed-venous level. The effect of lung collapse on human breath-hold diving capability is analysed using a computational model of the lungs and circulation that simulates oxygen, carbon dioxide, and nitrogen exchange between alveoli, blood, and tissues. Gas uptake during descent becomes limited by lung compression when the ratio of diffusing capacity to the product of perfusion and gas solubility in blood drops below one. An equation is derived for estimating collapse depth due to direct alveolar compression and time-dependent absorption atelectasis. Oxygen dissolved in blood during descent builds a limited capacitive store for supporting metabolism during the period of lung collapse. Hypoxemia with loss of consciousness prior to alveolar re-opening on ascent is predicted to occur on dives beyond 300 m, depending on initial lung volume.

Designing safety into the minimally invasive surgical revolution: a commentary based on the Jacques Perissat Lecture of the International Congress of the European Association for Endoscopic Surgery.

Surgical errors with minimally invasive surgery differ from those in open surgery. Perforations are typically the result of trocar introduction or electrosurgery. Infections include bioburdens, notably enteric viruses, on complex instruments. Retained foreign objects are primarily unretrieved device fragments and lost gallstones or other specimens. Fires and burns come from illuminated ends of fiber-optic cables and from electrosurgery. Pressure ischemia is more likely with longer endoscopic surgical procedures. Gas emboli can occur. Minimally invasive surgery is more dependent on complex equipment, with high likelihood of failures. Standardization, checklists, and problem reporting are solutions for minimizing failures. The necessity of electrosurgery makes education about best electrosurgical practices important. The recording of minimally invasive surgical procedures is an opportunity to debrief in a way that improves the reliability of future procedures. Safety depends on reliability, designing systems to withstand inevitable human errors. Safe systems are characterized by a commitment to safety, formal protocols for communications, teamwork, standardization around best practice, and reporting of problems for improvement of the system. Teamwork requires shared goals, mental models, and situational awareness in order to facilitate mutual monitoring and backup. An effective team has a flat hierarchy; team members are empowered to speak up if they are concerned about problems. Effective teams plan, rehearse, distribute the workload, and debrief. Surgeons doing minimally invasive surgery have a unique opportunity to incorporate the principles of safety into the development of their discipline.

Wrong-site surgery: can we prevent it?

Wrong-site surgery happens frequently enough that it is a significant risk for many surgeons during their professional careers. But it is an event that should never happen. Most wrong-site surgery is wrong-side surgery, followed by wrong-digit and wrong-vertebral-level surgery. Wrong-site surgery results from misinformation or misperception of the patient's orientation. The key to preventing wrong-site surgery is to have multiple independent checks of critical information. Discrepancies among the operative record, consent, and the surgeon's record of the history and physical examination should ideally be resolved prior to the day of surgery to avoid time-consuming reconciliations. We noted that the preoperative verification was the most effective of the three steps of the Universal Protocol and that the patient was a more reliable source of accurate information than the documents. Marking the operative site gives patients a voice after they are sedated or anesthesia is induced. Wrong-site surgery has involved local or regional anesthesia at the wrong site when anesthesiologists did not adhere to formal time-outs for their procedures. Surgeons need to have access to all relevant information and to be engaged in the processes to prevent wrong-site surgery, particularly in the final time-out. Junior members of the operating room team must be made comfortable about speaking up if concerned. During spinal surgery, the vertebral level needs to be confirmed radiographically. Wrong-site surgical problems can occur after an operation if accurate information is not provided to accompany the specimen or if leftover labels from a previous patient are used to identify the specimen.

A roadmap to safe surgical care: a view from Pennsylvania.

An effort to make operations safe is realistic if surgeons are committed. Such an effort involves educating surgeons about safe practices based on current knowledge of best practices, including team training and talking to patients. It involves identifying leaders and developing appropriate infrastructure for academic activities. It also involves the collection of information needed to identify safe and unsafe situations. The potential advantages of a drive for safe surgery should be fewer complications, less care per patient, lower costs, and less liability.

The role for leaders of health care organizations in patient safety.

We review what leaders of health care systems, including chief executive officers and board members, need to know to have "patient safety literacy" and do to make their systems safe. High reliability organizations produce reliable results that are not dependent on providers being perfect. Their characteristics include the commitment of leadership to safety as a system responsibility, with a culture of safety that decreases variability with standardized care and does not condone "at-risk behavior." A business case can be made for investing resources into systems that produce good outcomes reliably. Leaders must see patient safety problems as problems with their system, not with their employees. Leaders need to give providers information to make and monitor system progress. All medical errors, including near misses, and processes associated with all adverse events may provide information for system improvement. Improving systems should produce better long-term results than educating workers to be more careful.

Getting surgery right.

OBJECTIVE: We sought to identify factors contributing to wrong-site surgery (wrong patient, procedure, side, or part). METHODS: We examined all reports from all hospitals and ambulatory surgical centers--in a state that requires reporting of wrong-site surgery--from the initiation of the reporting requirement in June 2004 through December 2006. RESULTS: Over 30 months, there were 427 reports of near misses (253) or surgical interventions started (174) involving the wrong patient (34), wrong procedure (39), wrong side (298), and/or wrong part (60); 83 patients had incorrect procedures done to completion. Procedures on the lower extremities were the most common (30%). Common contributions to errors resulting in the initiation of wrong-site surgery involved patient positioning (20) and anesthesia interventions (29) before any planned time-out process, not verifying consents (22) or site markings (16), and not doing a proper time-out process (17). Actions involving operating surgeons contributed to 92. Common sources of successful recovery to prevent wrong-site surgery were patients (57), circulating nurses (30), and verifying consents (43). Interestingly, 31 formal time-out processes were unsuccessful in preventing "wrong" surgery. CONCLUSIONS: Wrong-site surgery continues to occur regularly, especially wrong-side surgery, even with formal site verification. Many errors occur before the time-out; some persist despite the verification protocol. Patients and nurses are the surgeons' best allies. Verification, starting with verification of the consent, needs to occur at multiple points before the incision.

How a system for reporting medical errors can and cannot improve patient safety.

The Institute of Medicine has recommended systems for reporting medical errors. This article discusses the necessary components of patient safety databases, steps for implementing patient safety reporting systems, what systems can do, what they cannot do, and motivations for physician participation. An ideal system captures adverse events, when care harms patients, and near misses, when errors occur without any harm. Near misses signal system weaknesses and, because harm did not occur, may provide insight into solutions. With an integrated system, medical errors can be linked to patient and team characteristics. Confidentiality and ease of use are important incentives in reporting. Confidentiality is preferred to anonymity to allow follow-up. Analysis and feedback are critical. Reporting systems need to be linked to organizational leaders who can act on the conclusions of reports. The use of statistics is limited by the absence of reliable numerators and denominators. Solutions should focus on changing the cultural environment. Patient safety reporting systems can help bring to light, monitor, and correct systems of care that produces medical errors. They are useful components of the patient safety and quality improvement initiatives of healthcare systems and they warrant involvement by physicians.

Translating patient safety legislation into health care practice.

BACKGROUND: An independent state agency, the Authority is charged with taking steps to reduce and eliminate medical errors by identifying problems and recommending solutions that promote patient safety. PENNSYLVANIA PATIENT SAFETY REPORTING SYSTEM (PA-PSRS): The Authority implemented PA-PSRS, a mandatory reporting and analysis system for both adverse events and near-misses, among 450 hospitals, birthing centers, and ambulatory surgical facilities. Pennsylvania is the only state to require the reporting of both adverse events and near-misses. THE PATIENT SAFETY ADVISORY: The Patient Safety Advisory is a quarterly publication containing articles about trends in reports submitted to PA-PSRS. The peer-reviewed articles include analysis of and lessons learned from PA-PSRS reports and evidence-based risk reduction strategies based on research in the clinical literature. To complement and reinforce the effectiveness of certain Advisory articles, the Authority has introduced electronic, educational tool kits on its Web site that can be downloaded. They include posters, draft policies, audio-slide presentations for staff training, and other materials related to clinical implementation of patient safety interventions and protocols. SUMMARY AND CONCLUSION: In just over two years, the Authority has developed a program that turns reports into actionable items through the analysis and research of adverse events and near-misses.

A surgeon who CARES can be safer.

The characteristics of a high-reliability organization are reviewed. Examples of how these characteristics relate to patient safety in surgical practice are illustrated by vignettes. The characteristics discussed include commitment to safety demonstrated to others by the conduct of one's practice; attention focused on one's own performance and the performance of others to the task at hand; rehearsal and proper preparation and contingency planning for procedures; effective communication so that information is accurate, adequate, unambiguous, and confirmed; and sense-making, or an understanding and verification of consistency between what is observed and expected and between what is planned and the premises for those plans.

The optimal initial management of children with suspected appendicitis: a decision analysis.

BACKGROUND/PURPOSE: As abdominal imaging has improved, the use of computed tomography (CT) and ultrasonography (US) for evaluating children with suspected appendicitis has increased. The purpose of this study was to determine the optimal management strategy for evaluating children with suspected appendicitis given the current accuracy of abdominal imaging. METHODS: Decision analysis was used to evaluate 5 management strategies: discharge, observation, CT, US, and appendectomy. Probabilities and time variables were obtained from publications and a chart review. Each approach was evaluated for its impact on length of stay, hospital charges, cost effectiveness and its capacity to minimize perforation and avoid negative appendectomy (risk-benefit). RESULTS: Discharge was preferred when the probability of appendicitis was low (<0.09 to <0.47), imaging when in an intermediate range and surgery when high (>0.61 to >0.91). A role for observation was found only when the anticipated time of inpatient observation was brief (<9 hours). Although CT was more expensive than US, CT was more cost effective for preventing negative appendectomy and perforation and achieved a better risk-benefit. CONCLUSIONS: CT has an important role in the management of suspected appendicitis. Among children with a low or high likelihood of appendicitis, the cost of imaging tests required to prevent the complications of appendicitis is high.