J Pediatr Intensive Care 2023; 12(02): 156-157
DOI: 10.1055/s-0041-1728640
Response from the Authors

Refractory Atelectasis and Response to Chest Physiotherapy

Alexandre T. Rotta
1   Division of Pediatric Critical Care Medicine, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States
,
Alejandro J. Martinez Herrada
2   Division of Pediatrics Critical Care Medicine, Department of Pediatrics, Rainbow Babies & Children's Hospital, Cleveland, Ohio, United States
,
Janine E. Zee-Cheng
3   Division of Hospital Medicine, Department of Pediatrics, Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana, United States
,
Steven L. Shein
2   Division of Pediatrics Critical Care Medicine, Department of Pediatrics, Rainbow Babies & Children's Hospital, Cleveland, Ohio, United States
› Author Affiliations

Refractory Atelectasis and Response to Chest Physiotherapy

We thank Gates et al for their interest in our recent publication[1] and appreciate the opportunity to respond to their comments. We admire their contributions to the field of pediatric airway clearance and are flattered by their engagement with our work.

Gates et al advance that some components of our maneuver have been well described in the literature, are commonly used in several countries globally, and fall under the general domain of chest physiotherapy. We are in complete agreement with that position. However, while we find similarities between our maneuver and techniques described in their state-of-the-art review[2] and original work,[3] [4] some of the components that we believe are critical to its success—namely, extrinsic restriction of contralateral chest wall expansion during manual hyperinflation, bilateral chest wall compression for forced exhalation conducted against ambient pressure, and slow tracheal suctioning under a derecruited state—were either not covered or not recommended by them.

Extrinsic restriction of the contralateral lung during manual inflation is of utmost importance to the success and safety of our maneuver. It helps direct gas to the affected lung while avoiding hyperinflation of the more compliant unaffected lung. Without it, manual inflation could lead to volutrauma, a concern that led Morrow[2] to recommend against this practice for routine airway clearance therapy. In addition, we find that bilateral chest wall compression for forced exhalation under zero positive end-expiratory pressure (PEEP) is also of paramount importance. While potentially viewed by some as counterintuitive or even detrimental—Gates et al wrote that “the requirement for complete derecruitment beyond lung closing volume is contrary to lung protective and open lung ventilation strategies,… potentially increasing the risk of lung injury”—this particular component of our maneuver maximizes expiratory flow bias and compresses the lungs toward the closing capacity, thus mobilizing secretions to the more central airway where they can then be suctioned out during a subsequent phase. The latter would be analogous to squeezing a wet sponge to mobilize its retained water. We are quite aware that lung injury can occur from what has been termed atelectrauma. However, the single derecruitment performed in preparation for suctioning is unlikely to lead to atelectrauma, which requires numerous repeated derecruitment/recruitment cycles over time, such as when severe lung injury is treated with insufficient PEEP.[5] [6] We elect to perform tracheal suction during this derecruited state because, during the development of our maneuver, we found that the addition of this step yielded significantly more respiratory secretions than when suction was performed under standard conditions (with PEEP). As explained in our article,[1] we then carefully re-recruit the lung with manual inflation back to what will hopefully be a more compliant organ with balanced aeration.

Gates et al stated that “It is unclear from the paper what alternative standard physiotherapy the group received.” We stipulated that, to qualify for the maneuver, patients needed to exhibit persistent atelectasis that was nonresponsive to standard treatment modalities, which comprised most of those described by Morrow.[2] These include therapeutic positioning, conventional chest physiotherapy (e.g., bag insufflation and chest manipulations or manual chest physiotherapy, followed by suctioning), chest percussion/vibration or high-frequency chest wall oscillation vest therapy, intrapulmonary percussive ventilation, nebulized hypertonic saline, and nebulized or instilled recombinant human DNase. Options from this “treatment menu” were cooperatively selected by the medical team and the group of expert physiotherapists (respiratory therapists) who also performed them. As advanced by Gates et al, the chosen treatments were based on clinical reasoning and were individualized by physiotherapists practicing at the top of their license. It was then presumed that, for these patients, atelectasis persisted despite what was believed to have been optimal and maximal treatment. Our maneuver does not seek to replace individualized treatments; to the contrary: it is to be performed as the exception, not the rule. Having said that, we believe that, when applied in this exact fashion once other modalities have failed, the maneuver has been shown effective by objective measures.

We thank Gates et al for raising the question regarding the use of neuromuscular blockade (NMB) in some of our patients. It goes without saying that NMB does not promote patient comfort and must only be used with appropriately deep sedation and analgesia, and never to mask patient discomfort. In our cohort, patients received NMB only when adequately sedated (which is routinely assessed with standardized scores in our pediatric intensive care unit) and if needed to facilitate performance of the maneuver. This is particularly important when spontaneous respiratory efforts interfere with optimal timing during coordinated maneuvers and diminish their efficacy, as elegantly demonstrated by Shannon et al.[4]

Finally, although we agree that point-of-care ultrasound could have a role in assessing resolution of atelectasis without exposure to ionizing radiation, we do not believe it to be superior to chest radiograph (at least in our hands). It is worth noting that, while some have performed better,[7] ultrasonography had an accuracy of only 72% for detecting atelectasis in the reference[8] cited by Gates et al, along with unacceptably low sensitivity (50%) and specificity (77%). We believe that electrical impedance tomography ([Fig. 1]) holds better promise, with the advantage of allowing for continued monitoring of lung recruitment, along with instantaneous assessment of gas distribution and regional hypo- or hyperinflation.

Zoom Image
Fig. 1 Digital image capture of electrical impedance tomography recordings taken from a 9-year-old child showing near-complete atelectasis of the right lung (premaneuver), contrasted with a more balanced ventilation pattern immediately following application of our maneuver (postmaneuver).


Publication History

Article published online:
21 June 2021

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