Cardiothoracic Surgery: Fellow Case Report Slide: Cardiothoracic Surgery |

Severe, Rapidly Reversible Hypoxemia in the Early Period After a Bilateral Lung Transplant FREE TO VIEW

Ankur Mishra, MD
Author and Funding Information

University of Iowa, Fargo, ND

Copyright 2016, American College of Chest Physicians. All Rights Reserved.

Chest. 2016;150(4_S):46A. doi:10.1016/j.chest.2016.08.053
Text Size: A A A
Published online

SESSION TITLE: Fellow Case Report Slide: Cardiothoracic Surgery

SESSION TYPE: Affiliate Case Report Slide

PRESENTED ON: Wednesday, October 26, 2016 at 11:00 AM - 12:15 PM

INTRODUCTION: A 63 year old female recipient of a bilateral lung transplant was clinically stable after extubation on post-op day 1. Early on the post-op day 2 she became hypertensive and was started on nicardipine infusion. Following this she developed rapidly worsening, severe hypoxemic respiratory failure on high flow nasal cannula with an estimated PaO2/FIO2 dropped from 207 to 69.

CASE PRESENTATION: A 63 year-old female patient with end-stage lung disease from IPF underwent a bilateral lung transplant. At 24 hours the patient was hemodynamically stable and on lung protective mechanical ventilation with estimated PaO2/FIO2 at 215. The patient was extubated and FO2 was weaned down to 0.45 by post-op day 1. Early on the post-op day 2, the patient became more hypertensive and an infusion of nicardipine was initiated. Soon after, the patient developed worsening respiratory failure and her oxygen requirements increased progressively. She was titrated up to a FO2 of 1.0 on a high flow nasal cannula. An ABG revealed a normal pCO2 and pH, but severe hypoxemia with estimated PaO2/FIO2 of 69 (Table 1). A follow up chest radiograph showed no acute change.

DISCUSSION: In the absence of the usual causes of hypoxemia in a lung transplant patient, we considered the timing of initiating nicardipine and the development of rapidly progressive, severe hypoxemia (Table 1). Nicardipine was discontinued. Over the next minutes to an hour, patient’s oxygenation improved. The FO2 could be weaned from 1.0 to 0.45 and the estimated PaO2/FIO2 improved from 69 to 240. Allograft function continued to improve and our patient was weaned to room air by post-op day 6. Hypoxic pulmonary vasoconstriction (HPV) is a reflex contraction of vascular smooth muscle in the pulmonary circulation when encountering hypoxia (1). HPV is mediated through L-type voltage gated calcium channels. Nicardipine is a potent inhibitor of HPV (2). A key function of HPV is reduce the impact of V/Q mismatch on gas exchange (Figure 1).

CONCLUSIONS: HPV is an important mechanism to optimize oxygenation of blood in the lung by matching local perfusion to local ventilation. This case highlights that pharmacological inhibition of HPV is an important consideration in the differential diagnosis of hypoxemia.

Reference #1: Sylvester JT, Shimoda LA, Aaronson PI, Ward JP. Hypoxic pulmonary vasoconstriction. Physiol Rev. 2012 Jan;92(1):367-520.

Reference #2: Nakazawa K, Amaha K. Effect of nicardipine hydrochloride on regional hypoxic pulmonary vasoconstriction. Br J Anaesth. 1988 Apr;60(5):547-54

DISCLOSURE: The following authors have nothing to disclose: Ankur Mishra

No Product/Research Disclosure Information




Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Find Similar Articles
CHEST Journal Articles
PubMed Articles
  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543