DOI: 10.5061/dryad.31zcrjdvj
title: Hypercapnia during transcatheter aortic valve replacement under monitored anesthesia care

description: Acute intraoperative hypercapnia and respiratory acidosis, which can occur
 during monitored anesthesia care (MAC), pose significant cardiopulmonary
 risks for patients with aortic stenosis presenting for transcatheter
 aortic valve replacement (TAVR). The goal of the present study is to
 assess the incidence, risk factors, and impact of intraoperative
 hypercapnia during MAC for patients undergoing transfemoral TAVR. Data
 were collected retrospectively from the electronic medical record of 201
 consecutive patients with available intraoperative arterial blood gas
 (ABG) data who underwent percutaneous transfemoral TAVR with MAC using
 propofol and dexmedetomidine.  ABGs (pH, PaCO2, PaO2) were
 performed at the start of each case (baseline), immediately prior to valve
 deployment (ValveDepl), and upon arrival to the Post Anesthesia Care Unit
 (PACU).  Data was analyzed using Fisher’s Exact Test, unpaired
 Student’s t test, Wilcoxon rank sum, or univariate linear regression as
 appropriate based on PaCO2 and pH during valve deployment
 (PaCO2-ValveDepl, pH-ValveDepl) and change in PaCO2and pH from baseline to
 valve deployment (PaCO2-%increase, pH-%decrease) to determine their
 association with preoperative demographic data, intraoperative anesthetic
 and vasoactive medications, and postoperative outcomes. PaCO2 increased by
 a mean of 28.4% and was higher than baseline in 91% of patients. 
 Younger age, male sex, increased weight, and increased propofol dose
 contributed to higher PaCO2-ValveDepl and greater
 PaCO2-%increase. Patients with PaCO2-ValveDepl &gt; 60 mmHg,
 pH ≤ 7.2, and greater pH-%decrease were more likely to receive vasoactive
 medications, but perioperative PaCO2 and pH were not associated with
 adverse postoperative outcomes. Transient significant hypercapnia commonly
 occurs during transfemoral TAVR with deep sedation using propofol and
 dexmedetomidine.  Although the incidence of postoperative
 outcomes does not appear to be affected by hypercapnia, the need for
 vasopressors and inotropes is increased.  If deep sedation is
 required for TAVR, hypercapnia and the need for hemodynamic and
 ventilatory support should be anticipated.
description: It is a retrospective cohort study. The data was acquired via
 review of patient charts on EHR after IRB approval. Processed with
 Fisher's exact test, Student's t test, Wilcoxon rank sum, and
 linear regression as appropriate.
description: # Hypercapnia during transcatheter aortic valve replacement under
 monitored anesthesia care
 [https://doi.org/10.5061/dryad.31zcrjdvj](https://doi.org/10.5061/dryad.31zcrjdvj) The dataset comprises raw data collected from patient charts, as well as data derived from statistical analysis. ## Description of the file structure "TAVR_MAC_data.csv" contains raw data obtained from patient charts and is the source of data used in statistical analysis. "pco2_60.txt", "pco2_50.txt", "pH_7.2.txt" compare variables based on pCO2 and pH cutoffs. Categorical variables were reported as counts and percentages, and continuous variables as mean ± SD.  Categorical variables were analyzed with Fisher’s Exact Test.  Continuous variables were analyzed using an unpaired Student’s t test or Wilcoxon rank sum (2-group comparison) as appropriate after being assessed for normality. "ALL_MAC_pts.txt" describes overall statistics of the study, as well as univariate linear regression analyses of predictors/impact of PCO2 and PCO2 %increase. "Linear_Regression_pH.txt" describes predictors of pH and pH-%decrease using univariate linear regression. "Predictors_of_outcomes.txt" attempts to pinpoint factors that predicted outcomes in the study using unpaired Student’s t test, Wilcoxon rank sum, and Fisher’s Exact Test. "Propofol_Age.txt" attempted to correlate propofol (sedative medication) dose and age. "Norepinephrine_BIS.txt" attempted to correlate norepinephrine dose and BIS (Bispectral Index). "BIS_inotrope.txt" uses univariate linear regression to assess the relationship between various factors and BIS and then describes factors that affect inotrope use using Fisher's exact test or Wilcoxon rank sum. "Vasoactive_Medications.txt" describes factors affecting vasoactive medication use using Fisher's exact test or Wilcoxon rank sum. In some cases, there may be several versions of the same data - these are repeats of prior statistical analysis with updates to include additional data for a few possible reasons. These include "update_Dexmed.txt", "update_Propofol_Dexmed_Norep.txt", "update_Med_dose.txt", "update_NOREPI.txt" * One analysis might only include medication dosing when the doses were not zero (i.e., the analysis excluded patients who did not receive the medication), while a repeat analysis might include these zero-doses. * incorrect data (when a medication dose in mcg/kg/hr was calculated incorrectly) - "update med dose," for example #### **Description of the data** The above data compares a number of variables related to medication data, procedural data, demographic data, and outcome data in the context of different arterial blood gas data (specifically, arterial partial pressure of carbon dioxide). Demographic data includes age, sex, BMI, and weight, as well as some relevant medical history. Medication data includes doses of midazolam, ketamine, dexmedetomidine, propofol, as well as norepinephrine equivalents (which were calculated from raw data using an equation that was obtained from the literature). Procedural data includes procedure time (in minutes) and in-operating room time (in minutes). Outcome data includes ICU and hospital length of stay, need for postoperative pacemaker (%), death at 30 days (%), ICU admission (%), stroke (%), delirium (%), and need for conversion to general anesthesia. Most of the data is self-explanatory. However, the following abbreviations need to be clarified. BMI: body mass index COPD: chronic obstructive pulmonary disease OSA: obstructive sleep apnea LVEF: left ventricular ejection fraction GFR: glomerular filtration rate RVSP: right ventricular systolic pressure pCO2: arterial partial pressure of carbon dioxide pO2: arterial partial pressure of oxygen BIS: bispectral index Dex/time/kg: dexmedetomidine infusion rate in mcg/kg/hr Propofol/time/kg: propofol infusion rate in mcg/kg/min Norepi/time/kg: norepinephrine infusion rate in mcg/kg/min Peri-deployment norepinephrine: norepinephrine infusion rate at the time of valve deployment GA: general anesthesia #### Sharing/Access information There is no other way to access this data. It was not derived from any other sources. ## Human subjects data This research study was approved by our institution's IRB. Written consent was deemed not necessary because it was a retrospective chart review study. The minimum amount of data necessary was collected in a de-identified form (with only age, sex, weight, BMI as identifiers) on an password protected, encrypted computer.