Richard J. Ward

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.

Unexpected cardiac arrest during spinal anesthesia: a closed claims analysis of predisposing factors.

Fourteen cases of sudden cardiac arrest in healthy patients who received spinal anesthesia were discovered in a preliminary review of 900 closed insurance claims for major anesthetic mishaps. All patients were resuscitated from the intraoperative cardiac arrest, but six suffered such severe neurologic injury that they died in hospital. Of the eight survivors, only one exhibited sufficient neurologic recovery to allow independence in daily self-care. In view of the unexpected nature of the cardiac arrests, as well as the ultimate severity of injury, these cases were analyzed in detail to determine whether there were recurring patterns of management that may have contributed to the occurrence or outcome of these anesthetic mishaps. Two patterns were identified. The first was the intraoperative use of sufficient sedation to produce a comfortable-appearing, sleep-like state in which there was no spontaneous verbalization. Cyanosis frequently heralded the onset of cardiac arrest in patients exhibiting this degree of sedation, suggesting that unappreciated respiratory insufficiency may have played an important role. The second pattern appeared to be an inadequate appreciation of the interaction between sympathetic blockade during high spinal anesthesia and the mechanisms of cardiopulmonary resuscitation. Prompt augmentation of central venous filling through the use of a potent α-agonist and positional change might have improved organ perfusion, shortened the duration of cardiac arrest, and lessened the degree of neurologic damage.

Nerve injury associated with anesthesia.

The authors examined the American Society of Anesthesiologists Closed Claims Study database to define the role of nerve damage in the overall spectrum of anesthesia-related injury that leads to litigation. Of 1,541 claims reviewed, 227 (15%) were for anesthesia-related nerve injury. Ulnar neuropathy represented one-third of all nerve injuries and was the most frequent nerve injury. Less-frequent sites of nerve injury were the brachial plexus (23%) and the lumbosacral nerve roots (16%). In a large proportion of cases, the exact mechanism of injury was unclear despite evidence of intensive investigation in the claim files. Median payment for nerve damage claims involving disabling injury was

Esophageal intubation: a review of detection techniques.

56,000, which was significantly lower than the

Role of monitoring devices in prevention of anesthetic mishaps: a closed claims analysis.

225,000 median payment for claims for disabling injury not involving nerve damage (P less than 0.01). The closed claims reviewers judged that the standard of care had been met significantly more often in claims involving nerve damage than in claims not involving nerve damage. The authors conclude that nerve damage is a significant source of anesthesia-related claims but that the exact mechanism of nerve injury is often unclear. In particular, ulnar nerve injuries seemed to occur without identifiable mechanism.

Effects of positional restraint on oxygen saturation and heart rate following exercise.

Although the first reported oral intubation of the human trachea occurred in 1878 (l), the procedure did not become standard practice until many years later. It is now a routinely performed procedure, one of the first techniques to be encountered by the anesthesia trainee. It is performed by individuals of different backgrounds and levels of training in the operating suite, emergency room, intensive care unit, hospital ward, and in the field. However, the frequency of tracheal intubation in modern anesthetic practice belies its importance, and the ability to accurately evaluate proper endotracheal tube position is crucial. A review of various anesthetic-related morbidity and mortality statistics (2-8) indicates that unrecognized esophageal intubation remains a problem, even among anesthesia personnel, a medical population specifically trained in such a procedure. An analysis of anesthetic accidents reported to the Medical Defence Union of the United Kingdom from 1970 to 1978 revealed that nearly half the cases resulting in death or cerebral damage were due to faulty technique (2). The technique most often identified as the source of mishap was tracheal intubation, with inadvertent esophageal tube placement the usual problem (2). Another review of anesthesia-related medical liability claims in the United Kingdom from 1977 to 1982 listed esophageal intubation as a ”main cause” of accidents leading to death or neurologic

Ventilatory Reserve and Level of Motor Block During High Spinal and Epidural Anesthesia

Anesthesiologist-reviewers examined 1,175 anesthetic-related closed malpractice claims from 17 professional liability insurance companies. The claims were filed between 1974 and 1988. The reviewers were asked to determine if the negative outcome was preventable by proper use of additional monitoring devices available at the time of the review even if not available at the time the incident occurred, and if so, which devices could have been preventative. In 1,097 cases sufficient information was available to make a judgment regarding preventability of the morbidity or mortality by application of additional monitoring devices. It was determined that 31.5% of the negative outcomes could have been prevented by application of additional monitors. Using the insurance industrys scale of 0 (no injury) to 9 (death), the median severity of injury for incidents deemed preventable was 9 compared with 5 for those deemed not preventable (P less than 0.01, scale detailed in text). The severity of injury scores were the same for preventable mishaps occurring during regional or general anesthesia, suggesting that additional monitoring devices may be equally efficacious in preventing serious negative outcomes during either regional or general anesthesia. The judgements or settlements of the incidents judged preventable by additional monitoring were 11 times more costly (P less than 0.01) than those mishaps not judged preventable. The monitors determined by the reviewers to be most useful in mishap prevention were pulse oximetry plus capnometry. Applied together, these two technologies were considered potentially preventative in 93% of the preventable mishaps.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiorespiratory effects of epinephrine when used in regional anesthesia.

This report assesses the effects on peripheral oxygen saturation and heart rate that positional restraint induces when a person is prone, handcuffed, and “hog-tied.” Peripheral oxygen saturation and heart rate were monitored at rest, during exercise, and during recovery from exercise for 10 adult subjects. The effects of positional restraint produced a mean recovery time that was significantly prolonged. Consequently, the physiological effects produced by positional restraint should be recognized in deaths where such measures are used

Intrathecal methadone: a dose-response study and comparison with intrathecal morphine 0.5 mg

Eighteen subjects were successively given spinal anesthesia with 50 to 75 mg. lidocaine, and epidural anesthesia with 15 to 35 ml of 2 per cent lidocaine containing 1:200,000 epinephrine. Mean levels of cutaneous analgesia (pin prick) and molor block (electromyography) were T 2.3 ±1.8 and T 5.1 ± 2.4, respectively, with spinal anesthesia, and T 3.6 ±1.2 and T 8.2 ±2.6 with epidural anesthesia. Mean inspiratory capacity fell 8 per cent with spinal anesthesia and 3 per cent with epidural anesthesia. Mean expiratory reserve volume fell 48 per cent with spinal anesthesia and 21 per cent with epidural anesthesia.

Peer reviewer agreement for major anesthetic mishaps.

The value of epinephrine to potentiate the action of local anesthetic agents has long been accepted by physicians, and it is frequently added to local anesthetic solutions. The main advantages of incorporating this vasoconstrictor in the anesthetic solutions are: (1) prolongation of anesthesia, and (2) reduction of the potential danger of systemic toxic reactions. When clinically accepted concentrations of this drug are employed, it has been assumed that there are no significant cardiovascular effects if the blood pressure, pulse and ECG remain within normal limits. Although epinephrine has been frequently incorporated into local anesthetic solutions ever since it was first advocated by Braun in 1900 (Braun and Shields ( 1914) 3), there have never been any properly controlled investigations concerning: (1) systemic cardiorespiratory effects of epinephrine when used in local anesthetic solutions; (2) magnitude and duration of the systemic cardiorespiratory effects when the dosage of epinephrine in the local anesthetic solution is varied; (3) how these systemic cardiorespiratory effects are altered when epinephrine is injected in different areas; and (4) duration of systemic cardiovascular and respiratory effects compared to duration of anesthesia. Our study was undertaken to examine these aspects of the problem under controlled conditions while employing sensitive techniques to measure cardiovascular and respiratory functions. These techniques included continuous arterial pressure and cardiac rate measurements, cardiac output determinations and stroke volume and total peripheral resistance calculations, in addition to measurements of arterial oxygen (PaO,) and carbon dioxide (PaCO,) tensions and pH.