Difficult mask ventilation in general surgical population: observation of risk factors and predictors

Abstract

Background: There are few predictors of difficult mask ventilation and a simple, objective, predictive system to identify patients at risk of difficult mask ventilation does not currently exist. We present a retrospective - subgroup analysis aimed at identifying predictive factors for difficult mask ventilation (DMV) in patients undergoing pre-operative airway assessment before elective surgery at a major teaching hospital. Methods: Data for this retrospective analysis were derived from a database of airway assessments, management plans, and outcomes that were collected prospectively from August 2008 to May 2010 at a Level 1 academic trauma center. Patients were stratified into two groups based on the difficulty of mask ventilation and the cohorts were analyzed using univariate analysis and stepwise selection method. Results: A total of 1399 pre-operative assessments were completed with documentation stating that mask ventilation was attempted. Of those 1399, 124 (8.9%) patients were found to be difficult to mask ventilate. A comparison of patients with and without difficult mask ventilation identified seven risk factors for DMV: age, body mass index (BMI), neck circumference, history of difficult intubation, presence of facial hair, perceived short neck and obstructive sleep apnea. Although seven risk factors were identified, no individual subject had more than four risk factors. Conclusion: The results of this study confirm that in a real world clinical setting, the incidence of DMV is not negligible and suggest the use of a simple bedside predictive score to improve the accuracy of DMV prediction, thereby improving patient safety. Further prospective studies to validate this score would be useful.

Non-opioid analgesic modes of pain management are associated with reduced postoperative complications and resource utilisation: a retrospective study of obstructive sleep apnoea patients undergoing elective joint arthroplasty

“…15,27 The lack of increase in genitourinary complications throughout all multimodal categories should also be noted, in light of the fact that complementary use of drugs such as NSAIDs, COX-2 inhibitors, and paracetamol/acetaminophen, have been associated with their own risks, including renal toxicity. 29,30 Notably, multimodal analgesia was also associated with a stepwise, continuous decrease in LOS by up to 11.8%, while a negligible effect was observed for cost of hospitalisation. The decrease in LOS, cost, and gastrointestinal complications with the use of multimodal analgesia could be related, given a recent population-based analysis in OSA patients demonstrating reduced odds for these complications at lower vs higher perioperative opioid dose concentrations.…”

“…2e4 Moreover, OSA has been linked to an increased risk for the presence of a difficult airway. 29,30 This is important, as the postoperative period is crucial given the exacerbation in sleep disordered breathing 31 at a time of highest levels of pain and analgesic requirement. Chung and colleagues 31 demonstrated that cumulative 72-h opioid dose appears to independently drive a higher postoperative apnoea-hypopnoea index, while others have described possible alterations in pain sensitivity and augmented opioid potency in OSA.…”

Predictive factors for difficult mask ventilation in the obese surgical population

“…A retrospective investigation was performed to identify predictive markers of DMV in obese patients at Memorial Hermann Hospital-Texas Medical Center utilizing an existing database of airway assessment and airway management records 4 , 14 : 1399 anesthetics were identified where both mask ventilation was attempted and a pre procedure airway evaluation was documented. Of these, 557 obese patients were identified and included for analysis.…”

“…Bag mask ventilation commonly precedes the establishment of a secure airway by endotracheal intubation. However, the degree of difficulty encountered is variable 1 – 4 , with the incidence of Difficult Mask Ventilation (DMV) varying from 0.08–15% depending on the criteria used for the definition. The American Society of Anesthesiologists’ (ASA) original definition recognized DMV as a situation where it is not possible for the unassisted anesthesiologist to maintain the oxygen saturation > 90% using 100% oxygen and positive pressure ventilation, or to prevent or reverse signs of inadequate ventilation 5 .…”

Mask Ventilation Grip: A Life-Saving Innovation

“…8 Patient characteristics that create higher rates of BMV difficulty include facial hair, lack of teeth, large neck circumference, obesity, sleep apnea, excessive pharyngeal tissue, inability to flex or extend the head, mandibular immobility, and old age. 7,9,10 Using a two-handed mask-face sealing technique has demonstrated the greatest success in delivering consistent, adequate tidal volumes during BMV in difficult patients as well as in the emergency department and out-of-hospital situations. 11,12 Documented complications of BMV are gastric inflation and aspiration of stomach contents.…”