Acurácia diagnóstica da variação da pressão de pulso mensurada em artéria periférica para predição de diferentes aumentos do volume sistólico em resposta ao desafio volêmico em cães
Arquivos
Data
2019-02-26
Autores
Dalmagro, Tábata Larissa
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Objetivo – Determinar a acurácia diagnóstica da variação da pressão de pulso (ΔPP) mensurada em artéria periférica na predição de diferentes aumentos no volume sistólico induzidos por um desafio volêmico em cães. Metodologia – Foram incluídos 39 cães, fêmeas (19,3 ± 3,6 kg) submetidas à ovariohisterectomia eletiva. A anestesia foi mantida com isoflurano sob ventilação mecânica controlada a volume (volume corrente 12 mL/kg; pausa inspiratória durante 40% do tempo inspiratório; relação inspiração:expiração 1:1,5). O débito cardíaco foi obtido através da técnica de termodiluição transpulmonar (cateter na artéria femoral) e o ΔPP foi mensurado através de um cateter posicionado na artéria podal dorsal. A fluido-responsividade (FR) foi avaliada através da administração de um (n = 21) ou dois (n = 18) desafios volêmicos com solução de Ringer Lactato (RL, 20 mL/kg durante 15 minutos), antes do procedimento cirúrgico. A análise da curva “receiver operating characteristics” (ROC) e a zona de incerteza diagnóstica (“gray zone”) do ΔPP foram empregadas para avaliar a habilidade do índice preditivo em discriminar os respondedores ao último desafio volêmico. A fluido-reponsividade foi definida por diferentes porcentagens de aumento no índice de volume sistólico (IVS) mensurado pela técnica de termodiluição transpulmonar (IVS>10%, IVS>15%, IVS>20% e IVS>25%). Resultados – O número de respondedores ao último desafio volêmico foi de 25 (IVS>10%), 21 (IVS>15%), 18 (IVS>20%) e 14 (IVS>25%). A área sob a curva ROC (AUROC) para o ΔPP foi 0,897 (IVS>10%), 0,968 (IVS>15%), 0,923 (IVS>20%) e 0,891 (IVS>25%) (p <0.0001 para AUROC = 0,5). As “gray zone” dos pontos de corte do ΔPP e a porcentagem de indivíduos dentro da gray zone foram: 6–14,6% (44%), 8,2–14,6% (31%), 9,5–14,6% (21%) e 8,6–16,6% (36%) para discriminar IVS>10%, IVS>15%, IVS>20% e IVS>25%, respectivamente. Conclusão – Valores de ΔPP acima de 14,6% mensurados em artéria periférica em cães saudáveis, podem predizer com melhor acurácia (“gray zone” mais estreita, contendo menos indivíduos da populção) que o VS aumentará em >20% em resposta a um desafio volêmico de 20 mL/kg de RL administrado em 15 minutos.
Objective – To determine the accuracy of pulse pressure variation (PPV) measured from a peripheral artery to predict different percent increases in stroke volume induced by a fluid challenge in dogs. Methods – Were included 39 adult bitches (19.3 ± 3.6 kg) undergoing ovariohysterectomy. Anesthesia was maintained with isoflurane under volumecontrolled ventilation (tidal volume 12 mL kg-1 ; inspiratory pause during 40% of inspiratory time; inspiration:expiration ratio 1:1.5). Cardiac output was obtained by transpulmonary thermodilution (femoral artery catheter) and PPV was measured from a dorsal pedal artery catheter. Fluid responsiveness (FR) was evaluated by a fluid challenge with lactated Ringer´s solution (LRS, 20 mL kg-1 over 15 minutes) administered once (n = 21) or twice (n = 18) before surgery. Receiver operating characteristics (ROC) curve analysis and the zone of diagnostic uncertainty (gray zone) of PPV cutoff thresholds were employed to evaluate the ability of PPV to discriminate responders to the last fluid challenge, defined by different percentage increases in stroke volume index (SVI) measured by transpulmonary thermodilution (SVI>10% to SVI> 25%, with 5 % increments). Results – Number of responders to the last fluid challenge were 25 (SVI>10%), 21 (SVI>15%), 18 (SVI>20%), and 14 (SVI>25%). The area under the ROC curve (AUROC) of PPV was 0.897 (SVI>10%), 0.968 (SVI>15%), 0.923 (SVI>20%), and 0.891 (SVI>25%) (p <0.0001 from AUROC = 0.5). Gray zones of PPV cutoff thresholds (percentage of individuals from population within the gray zones) were: 6–14.6% (44%), 8.2–14.6% (31%), 9.5–14.6% (21%) and 8.6–16.6% (36%) for discriminating SVI>10%, SVI>15%, SVI>20%, and SVI>25%, respectively. Conclusions – PPV values above 14.6% from a peripheral artery can predict with greater accuracy (narrower gray zone containing fewer individuals) that SVI will increase >20% in response to a 20 mL kg-1 LRS bolus administered over 15 minutes in healthy dogs.
Objective – To determine the accuracy of pulse pressure variation (PPV) measured from a peripheral artery to predict different percent increases in stroke volume induced by a fluid challenge in dogs. Methods – Were included 39 adult bitches (19.3 ± 3.6 kg) undergoing ovariohysterectomy. Anesthesia was maintained with isoflurane under volumecontrolled ventilation (tidal volume 12 mL kg-1 ; inspiratory pause during 40% of inspiratory time; inspiration:expiration ratio 1:1.5). Cardiac output was obtained by transpulmonary thermodilution (femoral artery catheter) and PPV was measured from a dorsal pedal artery catheter. Fluid responsiveness (FR) was evaluated by a fluid challenge with lactated Ringer´s solution (LRS, 20 mL kg-1 over 15 minutes) administered once (n = 21) or twice (n = 18) before surgery. Receiver operating characteristics (ROC) curve analysis and the zone of diagnostic uncertainty (gray zone) of PPV cutoff thresholds were employed to evaluate the ability of PPV to discriminate responders to the last fluid challenge, defined by different percentage increases in stroke volume index (SVI) measured by transpulmonary thermodilution (SVI>10% to SVI> 25%, with 5 % increments). Results – Number of responders to the last fluid challenge were 25 (SVI>10%), 21 (SVI>15%), 18 (SVI>20%), and 14 (SVI>25%). The area under the ROC curve (AUROC) of PPV was 0.897 (SVI>10%), 0.968 (SVI>15%), 0.923 (SVI>20%), and 0.891 (SVI>25%) (p <0.0001 from AUROC = 0.5). Gray zones of PPV cutoff thresholds (percentage of individuals from population within the gray zones) were: 6–14.6% (44%), 8.2–14.6% (31%), 9.5–14.6% (21%) and 8.6–16.6% (36%) for discriminating SVI>10%, SVI>15%, SVI>20%, and SVI>25%, respectively. Conclusions – PPV values above 14.6% from a peripheral artery can predict with greater accuracy (narrower gray zone containing fewer individuals) that SVI will increase >20% in response to a 20 mL kg-1 LRS bolus administered over 15 minutes in healthy dogs.
Descrição
Palavras-chave
Análise da curva ROC, Expansão volêmica, Fluidoterapia guiada por metas, Índices de pré-carga, Goal-directed fluid therapy, Preload indexes, ROC curve analysis, Volume expansion