Fig 1.
Endotracheal intubation in rats under the guidance of a visual laryngoscope.
(A) Exposure of rat glottis. (B) Placement of a guide wire through the glottis. (C) Placement of an endotracheal tube through a guidewire.
Table 1.
Key metrics of the modeling process.
Table 2.
Arterial blood gas parameters.
Fig 2.
Schematic overview of rat asphyxial cardiac arrest and cardiopulmonary resuscitation model.
(A) The rat during the molding process. (B) Overall diagram of the model. (C) Model instruments: ①multi-channel signal acquisition system; ②animal ventilator; ③anaesthesia machine; ④oxygenerator; ⑤ETCO2 monitor; ⑥visual laryngoscope.
Fig 3.
Typical arterial blood pressure and electrocardiogram during rat modeling.
(A) Before asphyxia; (B) During asphyxia; (C) Cardiac arrest; (D) Cardiopulmonary resuscitation; (E)ROSC; (F)1 minute after ROSC; (G)5 minutes after ROSC; (H)10 minutes after ROSC; (I)Torsades de pointes; (J)Fibrillation. ROSC: return of spontaneous circulation.
Fig 4.
Experimental flow chart.
Fig 5.
Groups with number of rats utilized and rationale for exclusion.
The rats in CA and Sham group were observed until the 14th day post-modeling.The surviving rats underwent histopathological evaluation of the brain.
Fig 6.
The variation trend of vital signs parameters during the overall process.
(A) HR; (B) MAP; (C) ETCO2; (D) RT; (E) HR trendgram; (F) ABP trendgram. T0: pre-asphyxia; T1: CA immediately; T2: ROSC immediately; T3: 1 minute after ROSC; T4: 5 minute after ROSC; T5: 10 minute after ROSC; T6: before extubation. **p <0.01,***p <0.001 at T1-T6 compared with T0.
Fig 7.
Long-term outcomes of rats after cardiac arrest.
(A)Kaplan-Meier analyses of cumulative survival during 14-day follow-up after ROSC. Sham group (n=6); CA group (n=28). (B)Variations in body weight observed within 14 days after ROSC. (C)The mNSS of survived rats at pre-asphyxia, 1,3,7,14 day after ROSC. (D)Chimney test results of survived rats at pre-asphyxia, 1,3,7,14 day after ROSC. (E)Schematic representation of the operational procedure for the Chimney text. **p <0.01,***p <0.001 compared with Sham group.
Fig 8.
Neuropathological damage is characterized by alterations observed in HE staining 14 days after resuscitation.
The black arrows in(D),(E),(F) point to damaged neurons.Scale bar=20µm.
Fig 9.
Neurons in the hippocampal CA1 region 14 days after resuscitation.
(A)Neurons in Sham group.(B)Neuronal details in Sham group. Black arrows point to normal mitochondria,blue arrows points to the endoplasmic reticulum, as well as the ribosomes that are attached to it. (C) Neurons in CA group. (D)Neuronal details in CA group. White arrow indicates the heterochromatin clusters in the nucleus, black arrows indicate mitochondria with disordered, fractured, and dissolved cristae, and blue arrow indicates a decrease in attached ribosomes.Scale bar in (A),(C)=2µm. Scale bar in (B),(D)=1µm.