Two-Handed Mask Ventilation by a Single Individual: A Quality Improvement Study

M. R. Salem, MD, A. Germanovich, DO, J. Mukalel, MD, N. N. Knezevic, MD, PhD, A. Khorasani, MD

Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, IL 60657 USA

Discussion

Abstract

References

In various airway management algorithms, reference to two-person mask ventilation is emphasized1. Benumof defined the optimal attempt at mask ventilation as a two person method with appropriately sized oro- or naso-pharyngeal airways2 (Figure 1.) Unfortunately, when unanticipated difficult mask ventilation is encountered, a second anesthesiologist is not always available. Rather than relying on another colleague to compress the reservoir bag, the anesthesiologist can use both hands to obtain appropriate mask seal, while the ventilator can be used to deliver the desired tidal volume. This quality improvement study was designed to test the hypothesis that residents can be trained to apply successfully “the one-person, two-handed mask ventilation” using a ventilator.

Introduction

ResultsMethodsAfter IRB approval, a total of 15 residents (5 from each CA year) participated in this quality improvement study, which was divided into Phase 1 and Phase 2. Residents were first instructed on performing the maneuver. In Phase 1 (23 patients; 14 females and 9 males), mask ventilation was performed prior to tracheal intubation in patients with normal airway. In Phase 2 (17 patients; 8 females and 9 males), the study was repeated in patients who had moderate or severe obstructive sleep apnea or were obese. After preoxygenation (ETO2>80%), induction with iv lidocaine, fentanyl and propofol, placement of an appropriately sized oropharyngeal airway, and 1-1.5 min after the administration of either succinylcholine or rocuronium, mask ventilation using the ventilator was initiated. The ventilator was set at volume mode with tidal volumes=400mL in women and 450 mL in men, a respiratory rate=14/min, I/E ratio of 1:2.1, and FIO2 > 0.9. (Figure 2.)

The following data were collected during ventilation for 1 min before intubation and for 1 min after intubation and cuff inflation: • expired tidal volume (VTexp)• expired minute ventilation (V min exp)• end tidal carbon dioxide (ETCO2)• SaO2

• peak airway pressure

Statistics Differences in VTexp,Vmin exp, ETCO2, SaO2 and peak airway pressure after and before intubation were analyzed using the Student’s t-test for paired samples. Each patient served as his/her control. SPSS software (SPSS 15.0, Chicago, IL) was used for statistical analysis.

Neither the one person, two-handed mask ventilation, nor use of the ventilator to deliver VT is new. In 1959, Safar et al.3 validated the usefulness of a two-handed jaw thrust method for reversing pharyngeal obstruction.Ventilators have been utilized in studying the efficacy of mask ventilation in children4 and have been suggested in the management of difficult mask ventilation in adults5,6

This study shows that, with minimal training, residents can effectively and easily perform “the one person, two-handed mask ventilation” in patients with normal and abnormal airways. Mastering the technique should enable the lone anesthesiologist to maintain adequate ventilation and oxygenation when difficult intubation (or difficult mask ventilation) is encountered and help is unavailable.

Conclusion

In Phase 1 and phase 2 there were no difference in VTexp and Vmin exp before and after intubation. However there was a slight, but statistically significant increase in peak airway pressure after intubation in phase 1 (Table 1.) Figure 3. represents our findings in a typical case.Residents’ performance in learning and performing the maneuver was judged as satisfactory.

The one-person, two-handed mask ventilation should be taught and practiced by all trainees.

1. El-Orbany M, Woehlck HJ. Anesth Analg 2009;109:1870-80. 2. Benumof JL. Airway management: principles and practice. Philadelphia, PA, Mosby Elsevier, 1996, pp. 121-5 3. Safar P et al. J Appl Physiol 1959;14:760-4 4.Salem MR, et al. Anesthesiology 1974;40:96-8 5.Benyamin RM, et al. Anesthesiology 1998;88:1134 6. Isono S. Anesthesiology 2008;109:576-7

ETCO2

mmHg30354045

Peak Airway Pressure

5101520

90

100

400450500

mL

cmH2O

VT exp

SaO2

(%)

Mask Ventilation After Intubation

• 43 y male• Wt: 110 kg

• OSA

• CA1 resident

Set up• TV 450mL • RR 14/min

• I/E 1:2.1• FIO2 >0.9

1 min 1 min

ParameterPHASE 1

During MV After Intubation

PHASE 2 During MV After Intubation

VTexp (mL)

438 ± 36 425 ± 37 438 ± 51 434 ± 45

Vmin exp (L/min)

6.1 ± 0.5 5.9 ± 0.5 6.1 ± 0.7 6.1 ± 0.6

Peak Airway Pressure(cm H2O)

11.1 ± 1.9 13.2 ± 3.4* 14.0 ± 3.1 16.6 ± 4.8

Table 1. VTexp, Vmin exp and peak airway pressure during mask

ventilation (MV) and ventilation after intubation using the same parameters

Figure 1.

Figure 3.

* p<0.001

This quality improvement study was designed to test the hypothesis that residents can be trained to apply successfully “the one-person, two-handed mask ventilation” using a ventilator. After IRB approval, a total of 15 residents (5 from each CA year) participated in this study which included 40 patients (23 with normal airway and 17 with moderate or severe obstructive sleep apnea or obesity).This study shows that, with minimal training, residents can effectively and easily perform this maneuver in patients with normal and abnormal airways. The one-person, two-handed mask ventilation should be taught and practiced by all trainees.

Figure 2.