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Biomedical subjects

K L Posner

Publications and source records attributed to K L Posner.

17 recordsLinked to original sources
PubMed1997

Adverse anesthetic outcomes arising from gas delivery equipment: a closed claims analysis.

BACKGROUND: Anesthesia gas delivery equipment is a potentially important source of patient injury. To better define the contribution of gas delivery equipment to professional liability in anesthesia, the authors conducted an in-depth analysis of cases from the database of the American Society of Anesthesiologists Closed Claims Project. METHODS: The database of the Closed Claims Project is composed of closed US malpractice claims that have been collected in a standardized manner. All claims resulting from the use of gas delivery equipment were reviewed for recurrent patterns of injury. RESULTS: Gas delivery equipment was associated with 72 (2%) of 3,791 claims in the database. Death and permanent brain damage accounted for almost all adverse outcomes (n = 55, 76%). Equipment misuse was defined as fault or human error associated with the preparation, maintenance, or deployment of a medical device. Equipment failure was defined as unexpected malfunction of a medical device, despite routine maintenance and previous uneventful use. Misuse of equipment (n = 54, 75%) was three times more common than equipment failure (n = 17, 24%). Misconnects and disconnects of the breathing circuit made the largest contribution to injury (n = 25, 35%). Reviewers judged that 38 of 72 claims (53%) could have been prevented by pulse oximetry, capnography, or a combination of these two monitors. Overall, 56 of 72 gas delivery claims (78%) were deemed preventable with the use or better use of monitors. The year of occurrence for claims involving gas delivery equipment ranged from 1962 to 1991 and did not differ significantly from claims involving other adverse respiratory events. CONCLUSIONS: Claims associated with gas delivery equipment are infrequent but severe and continue to occur in the 1990s. Educational and preventive strategies that focus on equipment misuse and breathing circuit configuration may have the greatest potential for enhancing the safety of anesthesia gas delivery equipment.

Anesthesiology↗
PubMed1997

Cost-effective reduction of neuromuscular-blocking drug expenditures.

BACKGROUND: Anesthetic drug expenditures have been a focus of cost-containment efforts. The aim of this study was to determine whether expenditures for neuromuscular-blocking agents could be reduced without compromising outcome, and to determine whether such a cost-effective pattern of neuromuscular blocker use could be sustained. METHODS: Education, practice guidelines, and paperwork barriers were used to persuade anesthesiologists to substitute low-cost neuromuscular-blocking drugs (pancuronium or a metocurine-pancuronium combination) for a more costly neuromuscular-blocking drug (vecuronium). Neuromuscular-blocking drug use in all patients during a historical control period (6 months; n = 4,804) was compared with that during two consecutive 1-yr periods of intervention (n = 9,761/n = 10,695). Expenditures for vecuronium and for all neuromuscular-blocking drugs were compared for the control and intervention periods. The rate of complications related to neuromuscular-blocking drugs was determined by an ongoing continuous quality improvement program. RESULTS: Vecuronium use decreased by 76% during the first and second yr of intervention, compared with the historical period (P < 0.01). The cost of neuromuscular-blocking drugs decreased by 31% (P < 0.01) and 47% (P < 0.01) for the first and second yr, respectively. The complication rate related to neuromuscular-blocking drugs was 0.081% in the historical period and 0.11% and 0.093% during the intervention periods (P = 0.29 and 0.41). CONCLUSION: Practice guidelines, education, and paperwork barriers used together substantially reduced the expenditures for neuromuscular-blocking drugs for 2 yr without adversely affecting clinical outcome.

Adult↗
PubMed1996

Variation in expert opinion in medical malpractice review.

BACKGROUND: Expert opinion in medical malpractice is a form of implicit assessment, based on unstated individual opinion. This contrasts with explicit assessment processes, which are characterized by criteria specified and stated before the assessment. Although sources of bias that might hinder the objectivity of expert witnesses have been identified, the effect of the implicit nature of expert review has not been firmly established. METHODS: Pairs of anesthesiologist-reviewers independently assessed the appropriateness of care in anesthesia malpractice claims. With potential sources of bias eliminated or held constant, the level of agreement was measured. RESULTS: Thirty anesthesiologists reviewed 103 claims. Reviewers agreed on 62% of claims and disagreed on 38%. They agreed that care was appropriate in 27% and less than appropriate in 32%. Chance-corrected levels of agreement were in the poor-good range (kappa = 0.37; 95% CI = 0.23 to 0.51). CONCLUSIONS: Divergent opinion stemming from the implicit nature of expert review may be common among objective medical experts reviewing malpractice claims.

Anesthesiology↗
PubMed1995

Changes in clinical practice in response to reductions in reimbursement: physician autonomy and resistance to bureaucratization.

This analysis of field data from 1991 and 1992 examines the process of joint decision making between cardiothoracic surgeons and anesthesiologists in a U.S. hospital as they made changes in clinical practice in response to reimbursement reductions. Although these physicians have concurrent responsibility for patient care in the operating room, their domains of authority are ambiguous. Much clinical decision making was found to be based on charismatic authority. In making practice changes, cardiothoracic surgeons maintained all and anesthesiologists most of their charismatic authority, expanding the conventional range of physician practice while prescribing specific practices for nonphysician providers. Ambiguity of joint physician authority over patient care was left unresolved, and the economic goals of the practice changes were not realized. Physicians resisted the bureaucratic claim to authority rooted in cost accounting by resorting to the need for nonroutinized clinical decisions.

Anesthesiology↗
PubMed1994

Burns from warming devices in anesthesia. A closed claims analysis.

BACKGROUND: Prevention of hypothermia is an important aspect of anesthetic management. Methods used for its prevention may, however, cause cutaneous burns. We reviewed the American Society of Anesthesiologists (ASA) Closed Claims Project database to determine if there were recurrent patterns of injury arising from intraoperative warming methods. METHODS: The ASA Closed Claims Project database is a collection of closed malpractice claims that have been reviewed in a standardized format. All claims for burns were reviewed. RESULTS: Among the 3,000 total claims there were 54 burns, of which 28 resulted from materials or devices used to warm patients. Intravenous fluid bags or bottles warmed in an oven and then applied to the patient's skin were responsible for 18 of the 28 (64%) burns associated with warming devices. These burns from intravenous fluid bags or bottles occurred in predominantly healthy (ASA physical status 1-2) young (age 38 +/- 17 yr, mean +/- standard deviation) women undergoing routine gynecologic or peripheral orthopedic surgery under general anesthesia. Of the eight burns from electrically powered warming equipment, five resulted from circulating-water mattresses. CONCLUSIONS: Intravenous fluid bags or bottles warmed in an operating room oven represent a hazard to anesthetized patients. Because intravenous fluid bags or bottles are not an efficient method of patient warming, there seems to be little justification for their use.

Adult↗
PubMed1994

Linking process and outcome of care in a continuous quality improvement program for anesthesia services.

We developed a continuous quality improvement (CQI) program for anesthesia services based on self-reporting of critical incidents and negative outcomes through a dichotomous (yes/no) response on the anesthesia record. Immediate case investigation provides data for systematic peer review of anesthesia management. Trend analysis of the database of critical incidents and negative outcomes identifies opportunities for improvement. The CQI program resulted in the reporting of nearly twice as many problems related to anesthesia management (5% of all anesthetics) as did the checklist it replaced (2.7%). Escalation of patient care (3.2%) and operational inefficiencies (2.2%) were more common than patient injury (1.5% of all anesthetics). Among the 537 cases with anesthesia management problems were 119 human errors and equipment problems (22%). Regional nerve blocks and airway management represented the most common problem areas. Improvement in anesthesia services was made through prompt implementation of strategies for problem prevention devised by the practitioners themselves through peer review, literature review, and clinical investigations.

Anesthesia Department, Hospital↗
PubMed1993

A comparison of pediatric and adult anesthesia closed malpractice claims.

BACKGROUND: Since 1985, the Committee on Professional Liability of the American Society of Anesthesiologists has evaluated closed anesthesia malpractice claims. This study compared pediatric and adult closed claims with respect to the mechanisms of injury, outcome, the costs, and the role of care judged to be substandard. METHODS: Using a standardized form and method developed for analysis of closed claims, the American Society of Anesthesiologists Closed Claims Data Base was used to compare pediatric with adult anesthesia-related adverse events. RESULTS: Of the 2,400 total claims, 238 (10%) were in the pediatric age group (15 yr of age or younger). The pediatric claims presented a different distribution of damaging events compared with that of adults. In particular, respiratory events were more common among pediatric claims (43% versus 30% in adult claims; P < or = 0.01). The mortality rate was greater in the pediatric claims (50% versus 35% in adult claims; P < or = 0.01), anesthetic care more often was judged less than appropriate (54% versus 44% in adult claims; P < or = 0.01), the complications more frequently were thought to be preventable with better monitoring (45% versus 30% in adult claims; P < or = 0.01), and the distribution of payments to the plaintiff was different (median payment, $111,234 versus $90,000 in adult claims; P < or = 0.05). Many of the differences between pediatric and adult claims were explained by a higher prevalence of patient injury caused by inadequate ventilation in the pediatric claims (20% versus 9% in adult claims; P < or = 0.01). In pediatric compared with adult inadequate ventilation claims, poor medical condition and/or obesity (6% versus 41%; P < or = 0.01) were uncommon associated factors. Cyanosis (49%) and/or bradycardia (64%) often preceded cardiac arrest in pediatric claims related to inadequate ventilation, resulting in death (70%) or brain damage (30%) in previously healthy children. Although clinical clues suggested hypoxemia as a common mechanism of injury, the files did not contain enough information to explain the genesis of hypoxemia in these claims. CONCLUSIONS: Comparison of adult and pediatric closed claims revealed a large prevalence of respiratory related damaging events--most frequently related to inadequate ventilation. In the opinion of the reviewers, 89% of the pediatric claims related to inadequate ventilation could have been prevented with pulse oximetry and/or end tidal CO2 measurement. However, pulse oximetry appeared to prevent poor outcome in only one of seven claims in which pulse oximetry was used and could possibly have done so.

Adolescent↗
PubMed1992

Eye injuries associated with anesthesia. A closed claims analysis.

Claims against anesthesiologists for eye injuries were analyzed as part of the ASA Closed Claims Project. Eye injury occurred in 3% of all claims in the database (71 of 2,046). The payment frequency for eye injury claims was higher than that for non-eye injury claims (70% vs. 56%; P less than or equal to 0.05). The median cost of eye injury claims was less than that for other claims ($24,000 vs. $95,000; P less than or equal to 0.01). Two distinct subsets were identified. The first was characterized by corneal abrasion during general anesthesia (25 of 71 claims; 35%). Claims for corneal abrasion were characterized by low incidence of permanent injury (16%) and low median payment ($3,000). Reviewers were able to identify a mechanism of injury in only 20% of claims for corneal abrasion. The second subset of eye injury was characterized by patient movement during ophthalmologic surgery (21 of 71; 30%). Blindness was the outcome in all cases. Sixteen of the claims involving movement occurred during general anesthesia, and 5 occurred during monitored anesthesia care. The median payment for claim involving movement was 10 times greater than for non-movement claims ($90,000 vs. $9,000; P less than or equal to 0.01). Anesthesiologist reviewers deemed the care rendered in the general anesthesia "movement" claims as meeting standards in only 19% of claims. From the perspective of patient safety, as well as risk management, these data suggest two specific needs: research directed at better understanding of the etiology of corneal abrasion and clinical strategies designed to assure patient immobility during ophthalmic surgery.

Adult↗
PubMed1991

Effect of outcome on physician judgments of appropriateness of care.

Is a permanent injury more likely to elicit a rating of inappropriate care than a temporary injury? To explore this question, we asked 112 practicing anesthesiologists to judge the appropriateness of care in 21 cases involving adverse anesthetic outcomes. The original outcome in each case was classified as either temporary or permanent. The authors then generated a matching alternate case identical to the original in every respect except that a plausible outcome of opposite severity was substituted. The original and alternate cases were randomly divided into two sets and assigned to reviewers who were blind to the intent of the study. The reviewers were asked to rate independently the care in each case as appropriate, less than appropriate, or impossible to judge, based on their personal (implicit) judgment of reasonable and prudent practice. A significant inverse relationship between severity of outcome and judgments of appropriateness of care was observed in 15 (71%) of the 21 matched pairs of cases. Overall, the proportion of ratings for appropriate care decreased by 31 percentage points when the outcome was changed from temporary to permanent and increased by 28 percentage points when the outcome was changed from permanent to temporary. We conclude that knowledge of the severity of outcome can influence a reviewer's judgment of the appropriateness of care.

Anesthesia↗
PubMed1991

A prospective study of intraoperative pulse oximetry failure.

Since pulse oximetry is now an ASA standard for intraoperative monitoring, we sought to determine the intraoperative failure rate for this device. We prospectively evaluated the intraoperative failure rate of our pulse oximeters at the four University of Washington Hospitals (University of Washington Medical Center, Veterans Affairs Medical Center [VAMC], Children's Hospital and Medical Center, and Harborview Medical Center [HMC]) recorded from April 1989 to August 1989. We defined failure as the inability to obtain any oximetry reading for a cumulative period of more than 30 minutes during any anesthetic procedure after all equipment malfunctions had been eliminated. Our puse oximeters failed in 124 of 11,046 cases studied; this is a failure rate of 1.12%, which ranged from 0.56% at HMC to 4.24% at VAMC. The failure rate at VAMC (4.24%) was significantly higher than the other hospitals (p less than 0.001). Those cases associated with the pulse oximeter failure had the following characteristics: (1) an ASA status of 3 or higher, (2) lengthy operations, and (3) elderly patients. When the device did fail in a patient, it did not function for 32% of the mean anesthesia time. We conclude that the intraoperative use of the pulse oximetry can provide information about blood oxygen saturation in most patients. However, in approximately 1% of the patients we studied in the operating room, mechanically functioning pulse oximeters failed to provide readings of blood oxygen saturations during routine operative use.

Equipment Failure↗
PubMed1991

A disposable end-tidal CO2 detector to verify endotracheal intubation.

STUDY OBJECTIVE: We compared the performance of the Fenem FEF end-tidal CO2 detector with the TRIMED capnometer to verify endotracheal intubation. DESIGN: The FEF indicates the presence of CO2 by the color change of a chemically treated indicator; the TRIMED uses infrared technology. Both devices were used during 60 intubations. SETTING: Intubations during in-hospital emergency situations outside of the operating room were studied. TYPE OF PARTICIPANTS: Adult patients undergoing intubation for respiratory failure, CPR, and other airway protection situations were enrolled in the study. INTERVENTIONS: The TRIMED monitor and FEF detector were placed in series between the manual resuscitator and the patient's endotracheal tube adapter after endotracheal tube placement. MEASUREMENTS AND MAIN RESULTS: We defined the acceptable criterion for detection of CO2 as production of a positive signal within six manual resuscitator bag breaths. The TRIMED met this criterion in 58 of 60 patients (sensitivity, 0.97) and the FEF met this criterion in 59 of 60 patients (sensitivity, 0.98). A paired t test showed no statistically significant difference in performance between the two devices. In five of nine cases of intubation during CPR, the color change of the FEF was described as "subtle." In one CPR case, a positive signal was not obtained by either device. CONCLUSION: We conclude that the performance of the FEF CO2 detector is equal to that of the TRIMED monitor for verification of endotracheal intubation in nonCPR situations. Interpretation of FEF color changes during CPR should be approached with caution until further studies using the FEF during CPR are completed.

Adult↗
PubMed1991

Adverse respiratory events infrequently leading to malpractice suits. A closed claims analysis.

Adverse outcomes associated with respiratory events are the single largest class of injury in the American Society of Anesthesiologists Closed Claims Project (762 of the 2,046 cases, 37%). Inadequate ventilation, esophageal intubation, and difficult tracheal intubation are the most common mechanisms of respiratory-related adverse outcomes. An analysis of closed claims data regarding these mechanisms has been reported previously. This report is concerned with 300 claims for five other less common but important categories of respiratory-related adverse outcomes in which recurrent themes of management error or patterns of injury could be identified: airway trauma, pneumothorax, airway obstruction, aspiration, and bronchospasm. Airway trauma (97 claims, 5% of the database) was associated with difficult intubation in 41 (42%) of the cases and the most frequent sites of injury were the larynx, pharynx, and esophagus. Pneumothorax (67 cases, 3% of the database) was usually either needle-related (block or central vascular catheter placement) or airway management-related (instrumentation or barotrauma). Airway obstruction (56 claims, 3% of the database) occurred in the upper airway in 39 (70%) of the cases. Aspiration (56 claims, 3% of the database) usually occurred during general anesthesia, either during induction prior to tracheal intubation or during maintenance of anesthesia delivered via mask. Bronchospasm (40 claims, 2% of the database) tended to occur during induction of general anesthesia in patients with a history of asthma or chronic obstructive pulmonary disease and/or smoking. The incidence of severe injury (brain damage and death) among these cases in the five categories was 47% overall, ranging from 12% in airway trauma claims to nearly 90% in claims for airway obstruction and bronchospasm.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Obstruction↗
PubMed1990

Measuring interrater reliability among multiple raters: an example of methods for nominal data.

This paper reviews and critiques various approaches to the measurement of reliability among multiple raters in the case of nominal data. We consider measurement of the overall reliability of a group of raters (using kappa-like statistics) as well as the reliability of individual raters with respect to a group. We introduce modifications of previously published estimators appropriate for measurement of reliability in the case of stratified sampling frames and we interpret these measures in view of standard errors computed using the jackknife. Analyses of a set of 48 anaesthesia case histories in which 42 anaesthesiologists independently rated the appropriateness of care on a nominal scale serve as an example.

Reproducibility of Results↗
PubMed1990

Adverse respiratory events in anesthesia: a closed claims analysis.

Adverse outcomes associated with respiratory events constitute the single largest class of injury in the American Society of Anesthesiology Closed Claims Study (522 of 1541 cases; 34%). Death or brain damage occurred in 85% of cases. The median cost of settlement or jury award was +200,000. Most outcomes (72%) were considered preventable with better monitoring. Three mechanisms of injury accounted for three-fourths of the adverse respiratory events: inadequate ventilation (196; 38%), esophageal intubation (94; 18%), and difficult tracheal intubation (87; 17%). Inadequate ventilation was used to describe claims in which it was evident that insufficient gas exchange had produced the adverse outcome, but it was not possible to identify the exact cause. This group was characterized by the highest proportion of cases in which care was considered substandard (90%). The esophageal intubation group was notable for a recurring diagnostic failure: in 48% of cases where auscultation of breath sounds was performed and documented, this test led to the erroneous conclusion that the endotracheal tube was correctly located in the trachea. Claims for difficult tracheal intubation were distinguished by a comparatively small proportion of cases (36%) in which the outcome was considered preventable with better monitoring. A better understanding of respiratory risks may require investigative protocols that initiate data collection immediately upon the recognition of a critical incident or adverse outcome.

Adolescent↗