**4. Outcome-driven anesthesia related morbidity and mortality**

In American Society of Anesthesiology (ASA) closed claims, the three leading respiratory events related to death or brain damage before 1990 were all nonaspiration related as; inadequate oxygenation/ventilation, difficult intubation and undetected esophageal intubation. Fortunately, the overall proportion of other non-aspiration respiratory-related death or brain death events have dramatically decreased over time, from 30% of the claims in the 1970s to 15% in the 1990s, possibly, due to incorporation of pulse oximetry, capnography and advent of supraglottic device and videoscopes into general clinical practice [12].

In ASA closed claims, the occurrence of aspiration has remained constant over time around 3.5%, with reduction of other non-aspiration respiratory claims. The mortality and brain death related to non-aspiration respiratory events have been decreasing since 1970 to 1990 from 50–30%. Surprisingly, to date still 60% of death and brain injury was attributed to aspiration compared to 43% for the remainder of the ASA claims [12].

In NAP4, among all respiratory claims, pulmonary aspiration contributed to only 5% of all claims. The topmost contributors to the NAP4 respiratory claims as 60% of the whole claims; were Inadequate ventilation, esophageal intubation and difficult intubation, all are considered as common risk factors for aspiration pneumonia. Still, the aspiration in NAP4 constitutes over 50% of airway-related deaths in anesthesia exceeding the feared consequence of cannot intubate cannot ventilate (CICV) scenario. 23% of all NAP4 claims have aspiration as either primary or secondary event. Cases not leading to mortality commonly resulted in significant morbidity and prolonged stay on intensive care [1].

#### **4.1 Risk factors of aspiration**

Risk factors cannot be ignored or easily overlooked in the preoperative assessment as 93% of aspiration cases in NAP4 have identifiable risk factors however the aspiration risk have been identified in only 40% of the primary anesthesia related aspiration. Thus, it mandates more judicious preoperative assessment [13] (**Table 1**).

#### *4.1.1 Poor airway assessment*

Poor assessment could lead equally to difficult airway scenarios and aspiration.

#### *4.1.2 Poor planning and prophylaxis*

Unstructured, inorganized and unplanned sequence for airway management.

#### *4.1.3 First generation supraglottic airway devices (SAD)*

Numerous cases of aspiration occurred during use of a first-generation SAD in patients who had multiple risk factors for aspiration and in several in whom the aspiration risk was so high that rapid sequence induction and intubation (RSII), should have been used [14].

#### *4.1.4 Obesity and after bariatric surgery*

Obesity is an independent risk factor for full stomach and airway management may be difficult in these patients, preoperative gastric ultrasound is recommended to assess the risk of aspiration. Complications in obese patient included an increased

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pneumonia [1].

*4.1.6 Number of intubation attempts*

reported after the second attempts [1].

*4.1.7 Underlying pathologies*

*4.1.7.1 Diabetes mellitus*

*Airway Management in Full Stomach Conditions DOI: http://dx.doi.org/10.5772/intechopen.93591*

• Upper abdominal or laparoscopic surgery • Positioning (lithotomy or Trendelenburg)

• Gastrointestinal obstruction/abdominal distension

• Upper gastrointestinal hemorrhage

• Diabetes mellitus or those with gastroparesis

• 1st Generation of Supra Glottic Device "SGA"

• Insufflation of stomach with bag mask ventilation or LMA

• Gastroesophageal reflux / Incompetent lower Esophageal Sphincter

• Intracranial hypertension

• Light depth of anesthesia

• Anesthesia delivered by Trainees

Surgical factors

Patient factors • Hiatal hernia

• Pregnancy • Morbid obesity

• ICU patients

• Opioids

**Table 1.**

Patient factors

• Emergency surgery (trauma)

• Prolonged surgery >2 h

frequency of aspiration and other complications during the use of SAD, difficulty at tracheal intubation and airway obstruction during emergence or recovery [15].

The 13% of the ASA aspiration claims have occurred during difficult airway

The NAP4 registry has found the number of attempts, and trials are significantly associated with higher rate of aspiration 22% regurgitation, 13% aspiration were

Diabetes is a common metabolic and endocrine disease, complicated with diabetic gastroparesis, known as gastric paralysis. It was found that hemoglobin

management. In NAP4, still the topmost contributors to respiratory claim were inadequate ventilation, esophageal intubation and difficult intubation report as 60% of the claims, and all that are common risk factors for aspiration

*4.1.5 Difficult airway and failure of airway management*

*Summary of the factors for aspiration pneumonia per Asai's risk factors [12].*

#### Surgical factors

*Special Considerations in Human Airway Management*

device and videoscopes into general clinical practice [12].

morbidity and prolonged stay on intensive care [1].

*4.1.3 First generation supraglottic airway devices (SAD)*

the ASA claims [12].

**4.1 Risk factors of aspiration**

*4.1.1 Poor airway assessment*

should have been used [14].

*4.1.4 Obesity and after bariatric surgery*

*4.1.2 Poor planning and prophylaxis*

**4. Outcome-driven anesthesia related morbidity and mortality**

respiratory events related to death or brain damage before 1990 were all nonaspiration related as; inadequate oxygenation/ventilation, difficult intubation and undetected esophageal intubation. Fortunately, the overall proportion of other non-aspiration respiratory-related death or brain death events have dramatically decreased over time, from 30% of the claims in the 1970s to 15% in the 1990s, possibly, due to incorporation of pulse oximetry, capnography and advent of supraglottic

In American Society of Anesthesiology (ASA) closed claims, the three leading

In ASA closed claims, the occurrence of aspiration has remained constant over time around 3.5%, with reduction of other non-aspiration respiratory claims. The mortality and brain death related to non-aspiration respiratory events have been decreasing since 1970 to 1990 from 50–30%. Surprisingly, to date still 60% of death and brain injury was attributed to aspiration compared to 43% for the remainder of

In NAP4, among all respiratory claims, pulmonary aspiration contributed to only 5% of all claims. The topmost contributors to the NAP4 respiratory claims as 60% of the whole claims; were Inadequate ventilation, esophageal intubation and difficult intubation, all are considered as common risk factors for aspiration pneumonia. Still, the aspiration in NAP4 constitutes over 50% of airway-related deaths in anesthesia exceeding the feared consequence of cannot intubate cannot ventilate (CICV) scenario. 23% of all NAP4 claims have aspiration as either primary or secondary event. Cases not leading to mortality commonly resulted in significant

Risk factors cannot be ignored or easily overlooked in the preoperative assessment as 93% of aspiration cases in NAP4 have identifiable risk factors however the aspiration risk have been identified in only 40% of the primary anesthesia related aspiration. Thus, it mandates more judicious preoperative assessment [13] (**Table 1**).

Poor assessment could lead equally to difficult airway scenarios and aspiration.

Unstructured, inorganized and unplanned sequence for airway management.

Numerous cases of aspiration occurred during use of a first-generation SAD in patients who had multiple risk factors for aspiration and in several in whom the aspiration risk was so high that rapid sequence induction and intubation (RSII),

Obesity is an independent risk factor for full stomach and airway management may be difficult in these patients, preoperative gastric ultrasound is recommended to assess the risk of aspiration. Complications in obese patient included an increased

**108**


#### Patient factors


#### Patient factors


#### **Table 1.**

*Summary of the factors for aspiration pneumonia per Asai's risk factors [12].*

frequency of aspiration and other complications during the use of SAD, difficulty at tracheal intubation and airway obstruction during emergence or recovery [15].
