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<article article-type="letter" dtd-version="1.0" specific-use="sps-1.8" xml:lang="en" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">
	<front>
		<journal-meta>
			<journal-id journal-id-type="publisher-id">rca</journal-id>
			<journal-title-group>
				<journal-title>Revista Colombiana de Anestesiología</journal-title>
				<abbrev-journal-title abbrev-type="publisher">Rev. colomb. anestesiol.</abbrev-journal-title>
			</journal-title-group>
			<issn pub-type="ppub">0120-3347</issn>
			<publisher>
				<publisher-name>SCARE-Sociedad Colombiana de Anestesiología y Reanimación</publisher-name>
			</publisher>
		</journal-meta>
		<article-meta>
			<article-id pub-id-type="doi">10.1097/CJ9.0000000000000034</article-id>
			<article-id pub-id-type="publisher-id">00017</article-id>
			<article-categories>
				<subj-group subj-group-type="heading">
					<subject>Response letter to the editor</subject>
				</subj-group>
			</article-categories>
			<title-group>
				<article-title>Reply to Letter to the Editor</article-title>
				<trans-title-group xml:lang="es">
					<trans-title>Respuesta carta al Editor</trans-title>
				</trans-title-group>
			</title-group>
			<contrib-group>
				<contrib contrib-type="author">
					<name>
						<surname>Botero-Rosas</surname>
						<given-names>Daniel Alfonso</given-names>
					</name>
					<xref ref-type="aff" rid="aff1"><sup>a</sup></xref>
					<xref ref-type="corresp" rid="c1"><sup>*</sup></xref>
				</contrib>
				<contrib contrib-type="author">
					<name>
						<surname>Mosquera-Dussán</surname>
						<given-names>Oscar Leonardo</given-names>
					</name>
					<xref ref-type="aff" rid="aff1_1"><sup>a</sup></xref>
				</contrib>
				<contrib contrib-type="author">
					<name>
						<surname>Oliveros</surname>
						<given-names>Henry</given-names>
					</name>
					<xref ref-type="aff" rid="aff2"><sup>b</sup></xref>
				</contrib>
			</contrib-group>
			<aff id="aff1">
				<label>a</label>
				<institution content-type="original"> Universidad de La Sabana, PROSEIM Research Group, Chía, Colombia.</institution>
				<institution content-type="normalized">Universidad de la Sabana</institution>
				<institution content-type="orgname">Universidad de La Sabana</institution>
				<addr-line>
					<named-content content-type="state">Chía</named-content>
				</addr-line>
				<country country="CO">Colombia</country>
			</aff>
			<aff id="aff1_1">
				<label>a</label>
				<institution content-type="original"> Universidad de La Sabana, PROSEIM Research Group, Chía, Colombia.</institution>
				<institution content-type="normalized">Universidad de la Sabana</institution>
				<institution content-type="orgname">Universidad de La Sabana</institution>
				<addr-line>
					<named-content content-type="state">Chía</named-content>
				</addr-line>
				<country country="CO">Colombia</country>
			</aff>
			<aff id="aff2">
				<label>b</label>
				<institution content-type="original"> School of Medicine, Universidad de La Sabana, Chía, Colombia.</institution>
				<institution content-type="normalized">Universidad de la Sabana</institution>
				<institution content-type="orgdiv1">School of Medicine</institution>
				<institution content-type="orgname">Universidad de La Sabana</institution>
				<addr-line>
					<named-content content-type="state">Chía</named-content>
				</addr-line>
				<country country="CO">Colombia</country>
			</aff>
			<author-notes>
				<corresp id="c1">
					<label><sup>*</sup></label> Correspondence: Universidad de La Sabana, Facultad de Medicina, Campus Universitario, Autopista Norte de Bogota, km 7, Puente Del Comun, Chía, Colombia. E-mail: daniel.botero@unisabana.edu.co</corresp>
			</author-notes>
			<pub-date pub-type="epub-ppub">
				<season>Apr-Jun</season>
				<year>2018</year>
			</pub-date>
			<volume>46</volume>
			<issue>2</issue>
			<fpage>177</fpage>
			<lpage>177</lpage>
			<permissions>
				<license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by-nc-nd/4.0/" xml:lang="en">
					<license-p>This is an open-access article distributed under the terms of the Creative Commons Attribution License</license-p>
				</license>
			</permissions>
			<counts>
				<fig-count count="0"/>
				<table-count count="0"/>
				<equation-count count="0"/>
				<ref-count count="3"/>
				<page-count count="1"/>
			</counts>
		</article-meta>
	</front>
	<body>
		<p>We wish to thank you foryourcomments<xref ref-type="bibr" rid="B1"><sup>1</sup></xref> to the Article &quot;Randomized cross-over clinical trial comparing to pharmacokinetic models of propofol using entropy indices,&quot;<xref ref-type="bibr" rid="B2"><sup>2</sup></xref> and we would like to submit some considerations and clarifications. (i) A propofol bolus (1mg/kg) was administered to facilitate airway management in both treatments (Marsh and Schnider). (ii) To avoid sharp entropy index transitions and ensure that the study period corresponded to an anesthetized patient, the index was considered following a delta time, defined as the time between the start of the propofol infusion with the first sequence model until the end of airway management, once the patient reached a stable conscious state. (iii) The statistical tests proposed by Wellek and Blettner<xref ref-type="bibr" rid="B3"><sup>3</sup></xref> for the determination of the &quot;carryover&quot; effect did not show significant statistical evidence pointing to an effect of the first treatment over the second one. This indicates that the 20-minute washout period was enough to prevent the first treatment from having an influence on the second. Propofol is short acting, and time to recovery of consciousness ranges between 5 and 10 minutes following bolus administration, due to reduced concentration in a rapid distribution phase lasting 2 to 4 minutes. In our study, the washout period was much longer than this recovery time.</p>
	</body>
	<back>
		<ref-list>
			<title>References</title>
			<ref id="B1">
				<label>1</label>
				<mixed-citation>1. Torres Cruz J. Comment about “Randomized cross-over clinical trial comparing two pharmacokinetic models of propofol using entropy indices”. Rev Colomb Anestesiol 2017;45: 80-81.</mixed-citation>
				<element-citation publication-type="journal">
					<person-group person-group-type="author">
						<name>
							<surname>Torres Cruz</surname>
							<given-names>J</given-names>
						</name>
					</person-group>
					<article-title>Comment about “Randomized cross-over clinical trial comparing two pharmacokinetic models of propofol using entropy indices”</article-title>
					<source>Rev Colomb Anestesiol</source>
					<year>2017</year>
					<volume>45</volume>
					<fpage>80</fpage>
					<lpage>81</lpage>
				</element-citation>
			</ref>
			<ref id="B2">
				<label>2</label>
				<mixed-citation>2. Mosquera-Dussán O, Cárdenas A, Botero-Rosas D, et al. Randomized cross-over clinical trial comparing two pharmacokinetic models of propofol using entropy indices. Rev Colomb Anestesiol 2016;44:194-202.</mixed-citation>
				<element-citation publication-type="journal">
					<person-group person-group-type="author">
						<name>
							<surname>Mosquera-Dussán</surname>
							<given-names>O</given-names>
						</name>
						<name>
							<surname>Cárdenas</surname>
							<given-names>A</given-names>
						</name>
						<name>
							<surname>Botero-Rosas</surname>
							<given-names>D</given-names>
						</name>
					</person-group>
					<article-title>Randomized cross-over clinical trial comparing two pharmacokinetic models of propofol using entropy indices</article-title>
					<source>Rev Colomb Anestesiol</source>
					<year>2016</year>
					<volume>44</volume>
					<fpage>194</fpage>
					<lpage>202</lpage>
				</element-citation>
			</ref>
			<ref id="B3">
				<label>3</label>
				<mixed-citation>3. Wellek S, Blettner M. On the proper use of the crossover design in clinical trials. Dtsch Arztebl Int 2012;109:276-281.</mixed-citation>
				<element-citation publication-type="journal">
					<person-group person-group-type="author">
						<name>
							<surname>Wellek</surname>
							<given-names>S</given-names>
						</name>
						<name>
							<surname>Blettner</surname>
							<given-names>M</given-names>
						</name>
					</person-group>
					<article-title>On the proper use of the crossover design in clinical trials</article-title>
					<source>Dtsch Arztebl Int</source>
					<year>2012</year>
					<volume>109</volume>
					<fpage>276</fpage>
					<lpage>281</lpage>
				</element-citation>
			</ref>
		</ref-list>
		<fn-group>
			<fn fn-type="other" id="fn1">
				<label>How to cite this article:</label>
				<p> Botero-Rosas DA, Mosquera-Dussán OL, Oliveros H. Reply to Letter to the Editor. Rev Colomb Anestesiol. Rev Colomb Anestesiol. 2018;46:177.</p>
			</fn>
			<fn fn-type="other" id="fn2">
				<label>Funding</label>
				<p> The authors declare having received no funding for the preparation of this manuscript.</p>
			</fn>
			<fn fn-type="other" id="fn3">
				<label>Conflict of interest</label>
				<p> The authors declare no conflict of interest in the preparation of the manuscript.</p>
			</fn>
		</fn-group>
	</back>
	<!--sub-article article-type="translation" id="s1" xml:lang="es">
		<front-stub>
			<article-categories>
				<subj-group subj-group-type="heading">
					<subject>Respuesta carta al editor</subject>
				</subj-group>
			</article-categories>
			<title-group>
				<article-title>Respuesta carta al Editor</article-title>
			</title-group>
			<contrib-group>
				<contrib contrib-type="author">
					<name>
						<surname>Botero-Rosas</surname>
						<given-names>Daniel Alfonso</given-names>
					</name>
					<xref ref-type="aff" rid="aff3"><sup>a</sup></xref>
					<xref ref-type="corresp" rid="c2"><sup>*</sup></xref>
				</contrib>
				<contrib contrib-type="author">
					<name>
						<surname>Mosquera-Dussán</surname>
						<given-names>Oscar Leonardo</given-names>
					</name>
					<xref ref-type="aff" rid="aff3"><sup>a</sup></xref>
				</contrib>
				<contrib contrib-type="author">
					<name>
						<surname>Oliveros</surname>
						<given-names>Henry</given-names>
					</name>
					<xref ref-type="aff" rid="aff4"><sup>b</sup></xref>
				</contrib>
			</contrib-group>
			<aff id="aff3">
				<label>a </label>
				<institution content-type="original">Universidad de La Sabana, Grupo de Investigación PROSEIM, Chía, Colombia.</institution>
			</aff>
			<aff id="aff4">
				<label>b </label>
				<institution content-type="original">Facultad de Medicina, Universidad de La Sabana, Chía, Colombia.</institution>
			</aff>
			<author-notes>
				<corresp id="c2">
					<label><sup>*</sup></label> Correspondencia: Universidad de La Sabana, Facultad de Medicina, Campus Universitario, Autopista Norte de Bogota, km 7, Puente Del Comun. Chía, Colombia. Correo electrónico: <email>daniel.botero@unisabana.edu.co</email>
				</corresp>
			</author-notes>
		</front-stub>
		<body>
			<p>Agradecemos los comentarios<xref ref-type="bibr" rid="B1"><sup>1</sup></xref> realizados al artículo, &quot;Ensayo clínico cruzado y aleatorizado para comparar 2 modelos farmacocinéticos de propofol usando índices de entropía&quot;,<xref ref-type="bibr" rid="B2"><sup>2</sup></xref> y presentamos algunas consideraciones y aclaraciones. i) Se administró un bolo de propofol (1mg/ kg) para facilitar el manejo de la vía aérea en ambos tratamientos (Marsh y Schnider). ii) Con el fin de evitar transiciones abruptas en el índice de entropía y asegurar que el periodo de análisis corresponde al de un paciente anestesiado, este fue considerado posterior a un tiempo delta,definido como el tiempo transcurrido desde el inicio de la infusión de propofol con el primer modelo de la secuencia hasta el final del manejo de la vía área, una vez el paciente alcanza un estado de conciencia estable. iii) Las pruebas estadísticas propuestas por Wellek y Blettner<xref ref-type="bibr" rid="B3"><sup>3</sup></xref> para determinar efecto de <italic>&quot;carryover&quot;</italic> o arrastre, no reportaron evidencia estadística significativa que indicara un efecto del primer tratamiento sobre el segundo, lo cual indica que el periodo de lavado W de 20 minutos fue suficiente para evitar que el primer tratamiento influyera sobre el segundo. El propofol tiene una acción corta y la recuperación del estado de conciencia puede variar entre 5 a 10 minutos después de la administración de un bolo, debido a la disminución en su concentración por una fase de distribución rápida, entre 2-4 minutos, en nuestro estudio el periodo de lavado estuvo bastante lejos de este tiempo de recuperación.</p>
			<sec>
				<title>Financiación</title>
				<p>Los autores no recibieron financiación para la escritura del presente manuscrito.</p>
			</sec>
			<sec>
				<title>Conflicto de intereses</title>
				<p>Los autores declaran que no existe conflicto de intereses en la elaboración del manuscrito.</p>
			</sec>
		</body>
		<back>
			<fn-group>
				<fn fn-type="other" id="fn4">
					<label>Cómo citar este artículo:</label>
					<p> Botero-Rosas DA, Mosquera-Dussán OL, Oliveros H. Respuesta carta al Editor. Rev Colomb Anestesiol. 2018;46:185.</p>
				</fn>
			</fn-group>
		</back>
	</sub-article-->
</article>