Anaesthetic Mortality Rates in Western Australia 1980–2002

Anaesthesiologists' clinical judgment accuracy regarding preoperative full stomach: Diagnostic study in urgent surgical adult patients

BACKGROUND

In urgent situations, preoperative full stomach assessment mostly relies on clinical judgment. Our primary objective was to assess the diagnostic performance of clinical judgment for the preoperative assessment of full stomach in urgent patients compared to gastric point-of-care ultrasound (PoCUS). Our secondary objective was to identify risk factors associated with PoCUS full stomach in urgent patients.

METHODS

We led a prospective observational study at our Hospital, between January and July 2016. Adult patients admitted for urgent surgery were eligible. Patients with altered gastric sonoanatomy, interventions reducing stomach content, impossible lateral decubitus were excluded. Clinical judgment and risk factors of full stomach were collected before gastric PoCUS measurements. Ultrasonographic full stomach was defined by solid contents or liquid volume ≥ 1.5 ml kg^-1. Diagnostic performance was assessed through sensitivity, specificity, accuracy, positive and negative predictive value.

RESULTS

The prevalence of clinical and PoCUS full stomach in 196 included patients was 29% and 27%, respectively. Positive and negative predictive values were 42% (95% CI: 32.3-52.6%) and 79% (95% CI: 74.9-83.4%), respectively. Patients with PoCUS full stomach were clinically misdiagnosed in 55% of cases. PoCUS full stomach was associated with abdominal or gynaecological-obstetrical surgery (OR 3.6, 95% CI: 1.5-8.8, P < 0.01) but not with fasting durations. Positive solid intake after illness onset with respect to 6-h solid fasting rule was associated with PoCUS low-risk gastric content (OR 0.4, 95% CI: 0.2-0.9, P = 0.03).

CONCLUSIONS

Clinical judgment showed poor-to-moderate performance in urgent surgical patients for the diagnosis of full stomach. Gastric PoCUS should be used to assess risk of full stomach in this population.

Working towards safer surgery in Africa; a survey of utilization of the WHO safe surgical checklist at the main referral hospitals in East Africa

Background

Mortality from anaesthesia and surgery in many countries in Sub-Saharan Africa remain at levels last seen in high-income countries 70 years ago. With many factors contributing to these poor outcomes, the World Health Organization (WHO) launched the “Safe Surgery Saves Lives” campaign in 2007. This program included the design and implementation of the “Surgical Safety Checklist”, incorporating ten essential objectives for safe surgery. We set out to determine the knowledge of and attitudes towards the use of the WHO checklist for surgical patients in national referral hospitals in East Africa.

Methods

A cross-sectional survey was conducted at the main referral hospitals in Mulago (Uganda), Kenyatta (Kenya), Muhimbili (Tanzania), Centre Hospitalier Universitaire de Kigali (Rwanda) and Centre Hospitalo-Universitaire de Kamenge (Burundi). Using a pre-set questionnaire, we interviewed anaesthetists on their knowledge and attitudes towards use of the WHO surgical checklist.

Results

Of the 85 anaesthetists interviewed, only 25 % regularly used the WHO surgical checklist. None of the anaesthetists in Mulago (Uganda) or Centre Hospitalo-Universitaire de Kamenge (Burundi) used the checklist, mainly because it was not available, in contrast with Muhimbili (Tanzania), Kenyatta (Kenya), and Centre Hospitalier Universitaire de Kigali (Rwanda), where 65 %, 19 % and 36 %, respectively, used the checklist.

Conclusion

Adherence to aspects of care embedded in the checklist is associated with a reduction in postoperative complications. It is therefore necessary to make the surgical checklist available, to train the surgical team on its importance and to identify local anaesthetists to champion its implementation in East Africa. The Ministries of Health in the participating countries need to issue directives for the implementation of the WHO checklist in all hospitals that conduct surgery in order to improve surgical outcomes.

Ultra-low-cost clinical pulse oximetry

An ultra-low-cost pulse oximeter is presented that interfaces a conventional clinical finger sensor with a mobile phone through the headset jack audio interface. All signal processing is performed using the audio subsystem of the phone. In a preliminary volunteer study in a hypoxia chamber, we compared the oxygen saturation obtained with the audio pulse oximeter against a commercially available (and FDA approved) reference pulse oximeter (Nonin Xpod). Good agreement was found between the outputs of the two devices.

Peri-operative pulse oximetry in low-income countries: a cost-effectiveness analysis

OBJECTIVE

To evaluate the cost-effectiveness of pulse oximetry--compared with no peri-operative monitoring--during surgery in low-income countries.

METHODS

We considered the use of tabletop and portable, hand-held pulse oximeters among patients of any age undergoing major surgery in low-income countries. From earlier studies we obtained baseline mortality and the effectiveness of pulse oximeters to reduce mortality. We considered the direct costs of purchasing and maintaining pulse oximeters as well as the cost of supplementary oxygen used to treat hypoxic episodes identified by oximetry. Health benefits were measured in disability-adjusted life-years (DALYs) averted and benefits and costs were both discounted at 3% per year. We used recommended cost-effectiveness thresholds--both absolute and relative to gross domestic product (GDP) per capita--to assess if pulse oximetry is a cost-effective health intervention. To test the robustness of our results we performed sensitivity analyses.

FINDINGS

In 2013 prices, tabletop and hand-held oximeters were found to have annual costs of 310 and 95 United States dollars (US$), respectively. Assuming the two types of oximeter have identical effectiveness, a single oximeter used for 22 procedures per week averted 0.83 DALYs per annum. The tabletop and hand-held oximeters cost US$ 374 and US$ 115 per DALY averted, respectively. For any country with a GDP per capita above US$ 677 the hand-held oximeter was found to be cost-effective if it prevented just 1.7% of anaesthetic-related deaths or 0.3% of peri-operative mortality.

CONCLUSION

Pulse oximetry is a cost-effective intervention for low-income settings.

Design and evaluation of a low-cost smartphone pulse oximeter

Infectious diseases such as pneumonia take the lives of millions of children in low- and middle-income countries every year. Many of these deaths could be prevented with the availability of robust and low-cost diagnostic tools using integrated sensor technology. Pulse oximetry in particular, offers a unique non-invasive and specific test for an increase in the severity of many infectious diseases such as pneumonia. If pulse oximetry could be delivered on widely available mobile phones, it could become a compelling solution to global health challenges. Many lives could be saved if this technology was disseminated effectively in the affected regions of the world to rescue patients from the fatal consequences of these infectious diseases. We describe the implementation of such an oximeter that interfaces a conventional clinical oximeter finger sensor with a smartphone through the headset jack audio interface, and present a simulator-based systematic verification system to be used for automated validation of the sensor interface on different smartphones and media players. An excellent agreement was found between the simulator and the audio oximeter for both oxygen saturation and heart rate over a wide range of optical transmission levels on 4th and 5th generations of the iPod TouchTM and iPhoneTM devices.

Primary anaesthetic deaths in Western Australia from 1985-2008: causation and preventability

This paper reports on the causes and preventability of primary anaesthetic deaths in Western Australia between 1985 and 2008. In Western Australia, it is a legal requirement to report all deaths that occur within 48 hours of an anaesthetic and later deaths if an anaesthetic complication is implicated. A committee assesses whether an anaesthetic factor caused the death (a primary anaesthetic death) or contributed to the death (an anaesthesia-related death). Of the 2361 deaths reported to the Committee over the 24-year period, 102 were considered anaesthesia-related and of these, 53 were considered a primary anaesthetic death. There were six main causes of primary anaesthetic death: failure to oxygenate; aspiration of gastric contents; adverse drug reaction; dose-related drug effect leading to an adverse cardiovascular event; intravascular injection of local anaesthetic; and injury related to an anaesthetic procedure or invasive monitoring. The most common cause was a dose-related drug effect leading to an adverse cardiovascular event. The medical condition of the patient was considered a significant contributing factor in 69% of the deaths and 72% were considered preventable. In the second 12-year period, there were fewer deaths overall (15 vs 38), proportionately fewer deaths related to failure to oxygenate (one vs six) and proportionately more deaths related to aspiration of gastric contents (four vs two). However, the percentage of deaths considered preventable was similar. These findings can be used to advise patients on anaesthetic risks, to educate anaesthetists about preventable deaths and to encourage the development of even safer anaesthetic drugs and techniques.

An iterative process of global quality improvement: the International Standards for a Safe Practice of Anesthesia 2010

Purpose

To enhance patient safety through contemporaneous and comprehensive standards for a safe practice of anesthesia that augment, enhance, and support similar standards already published by various countries and that provide a resource for countries that have yet to formulate such standards.

Standards development

The Safe Anesthesia Working Group of the World Health Organization’s “Safe Surgery Saves Lives” global initiative updated the 1992 International Standards for the Safe Practice of Anaesthesia (Standards) through an iterative process of literature review, consultation, debate, drafting, and refinement. These Standards address, in detail, the organization, support, practices, and infrastructure for anesthesia care. The Standards are grounded in the fundamental principle of safety in anesthesia, i.e., the continuous presence of an appropriately trained, vigilant anesthesia professional. In effect, the use of pulse oximetry during anesthesia is now considered mandatory, with acknowledgement that compromise may be unavoidable in emergencies. At the World Congress of Anaesthesiologists in 2008, drafts were presented for comment, further refinements were made, and the Revised Standards were adopted by the World Federation of Societies of Anaesthesiologists (WFSA). These Revised Standards were posted on the WFSA website for further feedback, and minor revisions followed. The International Standards for a Safe Practice of Anesthesia 2010 were endorsed by the Executive Committee of the WFSA in March 2010. Ongoing periodic revision is planned.

Conclusion

While they are universally applicable, the 2010 Standards primarily target lesser-resourced areas. They are designed particularly for regions that have yet to formulate or adopt their own standards so as to promote optimum patient outcomes in every anesthetizing location in the world.

Procedural sedation

PURPOSE OF REVIEW

To encapsulate the recent developments in endoscopic procedural sedation from the standpoints of safety, efficacy and policy.

RECENT FINDINGS

Initial studies addressing the presence of obstructive sleep apnea in patients undergoing upper endoscopy and colonoscopy did not find an increased risk of cardiopulmonary complications. A worldwide study of 646 080 patients receiving endoscopist-directed propofol sedation found a mortality rate of one per 161 515 cases, which all occurred in patients with high-risk comorbidities. The incidence of bag mask ventilation was significantly higher for upper endoscopy when compared to colonoscopy (185/185 245; 0.1% vs. 20/142 863, 0.01%; P<0.001).

SUMMARY

The presence of obstructive sleep apnea whether diagnosed by a surrogate validated questionnaire to by the gold standard sleep study does not appear to lead to increased rates of hypoxemia in patients undergoing ambulatory upper endoscopy. Endoscopist-directed propofol sedation is well tolerated in the appropriately selected patient. The use of anesthesia-assisted sedation for American Society of Anesthesiologists class I and II patients for upper endoscopy and colonoscopy is cost-ineffective.

Endoscopist-directed administration of propofol: a worldwide safety experience

BACKGROUND & AIMS

Endoscopist-directed propofol sedation (EDP) remains controversial. We sought to update the safety experience of EDP and estimate the cost of using anesthesia specialists for endoscopic sedation.

METHODS

We reviewed all published work using EDP. We contacted all endoscopists performing EDP for endoscopy that we were aware of to obtain their safety experience. These complications were available in all patients: endotracheal intubations, permanent neurologic injuries, and death.

RESULTS

A total of 646,080 (223,656 published and 422,424 unpublished) EDP cases were identified. Endotracheal intubations, permanent neurologic injuries, and deaths were 11, 0, and 4, respectively. Deaths occurred in 2 patients with pancreatic cancer, a severely handicapped patient with mental retardation, and a patient with severe cardiomyopathy. The overall number of cases requiring mask ventilation was 489 (0.1%) of 569,220 cases with data available. For sites specifying mask ventilation risk by procedure type, 185 (0.1%) of 185,245 patients and 20 (0.01%) of 142,863 patients required mask ventilation during their esophagogastroduodenoscopy or colonoscopy, respectively (P < .001). The estimated cost per life-year saved to substitute anesthesia specialists in these cases, assuming they would have prevented all deaths, was $5.3 million.

CONCLUSIONS

EDP thus far has a lower mortality rate than that in published data on endoscopist-delivered benzodiazepines and opioids and a comparable rate to that in published data on general anesthesia by anesthesiologists. In the cases described here, use of anesthesia specialists to deliver propofol would have had high costs relative to any potential benefit.

The impact of trained assistance on error rates in anaesthesia: a simulation-based randomised controlled trial

Trained assistance for the anaesthetist appears likely to improve safety in anaesthesia. However, there are few objective data to support this assumption, and the requirement for a trained assistant is not universally enforced. We applied a simulation-based model developed in previous work to test the hypothesis that the presence of a trained assistant reduces error in anaesthesia. Ten randomly selected anaesthetists, five trained anaesthetic technicians and five theatre nurses without training in anaesthesia participated in two simulated emergencies, with anaesthetists working alternately with a technician or a nurse. The mean (SD) error rate per scenario was 4.75 (2.9). There were significantly fewer errors in the technician group than the nurse group (33 vs 62, p = 0.01) and this difference remained significant when errors were weighted for severity. This provides objective evidence supporting the requirement for trained assistance to the anaesthetist, and furthermore, demonstrates that a simulation-based model can provide rigorous evidence on safety interventions in anaesthesia.

Nonpharmacological, somatic treatments of depression: electroconvulsive therapy and novel brain stimulation modalities

Until recently, a review of nonpharmacological, somatic treatments of psychiatric disorders would have included only electroconvulsive therapy (ECT). This situation is now changing very substantially. Although ECT remains the only modality in widespread clinical use, several new techniques are under investigation. Their principal indication in the psychiatric context is the treatment of major depression, but other applications are also being studied. All the novel treatments involve brain stimulation, which is achieved by different technological methods. The treatment closest to the threshold of clinical acceptability is transcranial magnetic stimulation (TMS). Although TMS is safe and relatively easy to administer, its efficacy has still to be definitively established. Other modalities, at various stages of research development, include magnetic seizure therapy (MST), deep brain stimulation (DBS), and vagus nerve stimulation (VNS). We briefly review the development and technical aspects of these treatments, their potential role in the treatment of major depression, adverse effects, and putative mechanism of action. As the only one of these treatment modalities that is in widespread clinical use, more extended consideration is given to ECT Although more than half a century has elapsed since ECT was first introduced, it remains the most effective treatment for major depression, with efficacy in patients refractory to antidepressant drugs and an acceptable safety profile. Although they hold considerable promise, the novel brain stimulation techniques reviewed here will be need to be further developed before they achieve clinical acceptability.