Patient safety during procedural sedation using capnography monitoring: a systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of capnography monitoring on sedation-related adverse events during procedural sedation and analgesia (PSA) administered for ambulatory surgery relative to visual assessment and pulse oximetry alone.

DESIGN AND SETTING

Systematic literature review and random effects meta-analysis of randomised controlled trials (RCTs) reporting sedation-related adverse event incidence when adding capnography to visual assessment and pulse oximetry in patients undergoing PSA during ambulatory surgery in the hospital setting. Searches for eligible studies published between 1 January 1995 and 31 December 2016 (inclusive) were conducted in PubMed, the Cochrane Library and EMBASE without any language constraints. Searches were conducted in January 2017, screening and data extraction were conducted by two independent reviewers, and study quality was assessed using a modified Jadad scale.

INTERVENTIONS

Capnography monitoring relative to visual assessment and pulse oximetry alone.

PRIMARY AND SECONDARY OUTCOME MEASURES

Predefined endpoints of interest were desaturation/hypoxaemia (the primary endpoint), apnoea, aspiration, bradycardia, hypotension, premature procedure termination, respiratory failure, use of assisted/bag-mask ventilation and death during PSA.

RESULTS

The literature search identified 1006 unique articles, of which 13 were ultimately included in the meta-analysis. Addition of capnography to visual assessment and pulse oximetry was associated with a significant reduction in mild (risk ratio (RR) 0.77, 95% CI 0.67 to 0.89) and severe (RR 0.59, 95% CI 0.43 to 0.81) desaturation, as well as in the use of assisted ventilation (OR 0.47, 95% CI 0.23 to 0.95). No significant differences in other endpoints were identified.

CONCLUSIONS

Meta-analysis of 13 RCTs published between 2006 and 2016 showed a reduction in respiratory compromise (from respiratory insufficiency to failure) during PSA with the inclusion of capnography monitoring. In particular, use of capnography was associated with less mild and severe oxygen desaturation, which may have helped to avoid the need for assisted ventilation.

Traumatic intracranial injury in intoxicated patients with minor head trauma

OBJECTIVES

Studies focusing on minor head injury in intoxicated patients report disparate prevalences of intracranial injury. It is unclear if the typical factors associated with intracranial injury in published clinical decision rules for computerized tomography (CT) acquisition are helpful in differentiating patients with and without intracranial injuries, as intoxication may obscure particular features of intracranial injury such as headache and mimic other signs of head injury such as altered mental status. This study aimed to estimate the prevalence of intracranial injury following minor head injury (Glasgow Coma Scale [GCS] score ≥14) in intoxicated patients and to assess the performance of established clinical decision rules in this population.

METHODS

This was a prospective cohort study of consecutive intoxicated adults presenting to the emergency department (ED) following minor head injury. Historical and physical examination features included those from the Canadian CT Head Rule, National Emergency X-Radiography Utilization Study (NEXUS), and New Orleans Criteria. All patients underwent head CT.

RESULTS

A total of 283 patients were enrolled, with a median age of 40 years (interquartile range [IQR] = 28 to 48 years) and median alcohol concentration of 195 mmol/L (IQR = 154 to 256 mmol/L). A total of 238 of 283 (84%) were male, and 225 (80%) had GCS scores of 15. Clinically important injuries (injuries requiring admission to the hospital or neurosurgical follow-up) were identified in 23 patients (8%; 95% confidence interval [CI] = 5% to 12%); one required neurosurgical intervention (0.4%, 95% CI = 0% to 2%). Loss of consciousness and headache were associated with clinically important intracranial injury on CT. The Canadian CT Head Rule had a sensitivity of 70% (95% CI = 47% to 87%) and NEXUS criteria had a sensitivity of 83% (95% CI = 61% to 95%) for clinically important injury in intoxicated patients.

CONCLUSIONS

In this study, the prevalence of clinically important injury in intoxicated patients with minor head injury was significant. While the presence of the common features associated with intracranial injury in nonintoxicated patients should raise clinical suspicion for intracranial injury in intoxicated patients, the Canadian CT Head Rule and NEXUS criteria do not have adequate sensitivity to be applied in intoxicated patients with minor head injury.

Noninvasive diagnosis of blunt cerebrovascular injuries: a preliminary report

BACKGROUND

In light of their potential for devastating consequences, a liberalized screening approach for blunt cerebrovascular injuries (BCVI) is becoming increasingly accepted. The "gold standard" for diagnosis of BCVI is arteriography; however, noninvasive diagnostic alternatives offer clear advantages. Recent series have demonstrated the ability of computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) to identify BCVI, but have not compared their accuracy with arteriography. We hypothesized that CTA or MRA could reliably identify BCVI, obviating the need for arteriography. The purpose of this study was to determine the accuracy of CTA and MRA in identifying BCVI in asymptomatic patients.

METHODS

Asymptomatic patients meeting criteria for BCVI screening underwent arteriography, according to our institutional standard. A subset of patients requiring computed tomographic scanning underwent CTA; a subset of patients requiring magnetic resonance imaging underwent MRA. All of the studies were interpreted by radiologists in a blinded manner. Data were analyzed for sensitivity and specificity.

RESULTS

Forty-six patients underwent both CTA and arteriography. Of 23 with a normal CTA examination, 7 (30%) had BCVI on arteriography. Of 23 with an abnormal CTA examination, 8 (35%) had a normal arteriogram. The sensitivity, specificity, positive predictive value, and negative predictive value of CTA were 68%, 67%, 65%, and 70%, respectively. CTA missed 55% of grade I injuries, 14% of grade II injuries, and 13% of grade III injuries. Sixteen patients underwent both MRA and arteriography. One (11%) had a false-negative MRA result, and four (57%) had false-positive MRA results (75% sensitivity, 67% specificity, 43% positive predictive value, 89% negative predictive value).

CONCLUSION

CTA and MRA can identify BCVI, but they miss grade I, II, and III injuries. Future technical modifications may improve their accuracy. A prospective multicenter trial is warranted to define the capabilities and limitations of these noninvasive modalities. In the interim, arteriography remains the gold standard for diagnosis, but if arteriography is not available, CTA or MRA should be used to screen for BCVI in patients at risk.

Quantitative sensitivity of ultrasound in detecting free intraperitoneal fluid

The minimum volume of intraperitoneal fluid that is detectable in Morison's pouch with ultrasound in the trauma setting is not well defined. To evaluate this question, we used diagnostic peritoneal lavage (DPL) as a model for intraperitoneal hemorrhage and undertook a blinded prospective study of the sensitivity of ultrasound in detecting intraperitoneal fluid. Participants included attending physicians and residents in emergency medicine, radiology, and surgery. During the infusion of the DPL fluid, participants continuously scanned Morison's pouch until they detected fluid. All participants were blinded to the rate of infusion and the volume infused. One hundred patients were entered into the study. The mean volume of fluid detected was 619 mL. Only 10% of participants detected fluid volumes less than 400 mL and the overall sensitivity at one liter was 97%. We conclude that reliable detection of intraperitoneal fluid in Morison's pouch requires a greater volume than has been previously described.

Intravascular ultrasonography for the diagnosis of traumatic aortic disruption: a case report

Thoracic aortic disruptions after blunt trauma are highly lethal injuries. Diagnosis of these injuries has traditionally been based on clinical suspicion, chest radiographs, and aortography. The roles of dynamic computed tomography and transesophageal echocardiography are currently under investigation. Intravascular ultrasonography is a new technology with potential as a diagnostic adjunct in the evaluation of these injuries. We present a case of traumatic aortic disruption identified by intravascular ultrasonography after nondiagnostic aortography and dynamic computed tomography studies.