Establishing a resuscitation model in rabbits with closed-thoracic cardiopulmonary by-pass

A case report: A patient rescued by VA-ECMO after cardiac arrest triggered by trigeminocardiac reflex after nasal surgery

RATIONALE

Cardiac arrest (CA) caused by trigeminocardiac reflex (TCR) after endoscopic nasal surgery is rare. Hence, when a patient suffers from TCR induced CA in the recovery room, most doctors may not be able to find the cause in a short time, and standard cardiopulmonary resuscitation and resuscitation measures may not be effective. Providing circulatory assistance through venous-arterial extracorporeal membrane oxygenation (VA-ECMO) can help healthcare providers gain time to identify the etiology and initiate symptom-specific treatment.

PATIENT CONCERNS

We report a rare case of CA after endoscopic nasal surgery treated with VA-ECMO.

DIAGNOSES

We excluded myocardial infarction, pulmonary embolism, allergies, hypoxia, and electrolyte abnormalities based on the relevant examination results. Following a multidisciplinary consultation, clinical manifestation and a review of previous literature, we reasoned that the CA was due to TCR.

INTERVENTIONS

VA-ECMO was established to resuscitate the patient successfully during effective cardiopulmonary resuscitation.

OUTCOMES

ECMO was successfully evacuated a period of 190 minutes of therapy. The patient was discharged home on day 8.

LESSONS

TCR is notable during endoscopic nasal surgery. Our case indicates that CA in operating room is worth prolonged CCPR. The ideal time for ECPR implementation should not be limited within 20 minutes after CCPR.

Investigation of the relationship between venticular fibrillation duration and cardiac/neurological damage in a rabbit model of electrically induced arrhythmia

BACKGROUND

To establish a simple, economic, and reliable alternating current (AC)-induced cardiac arrest (ACCA) model in rabbits for cardiopulmonary cerebral resuscitation research.

METHODS

Ventricular fibrillation was induced in 27 New Zealand rabbits by external transthoracic AC, which were randomly divided into three groups according to the duration of untreated ACCA (ACCA-3 minutes, ACCA-5 minutes, and ACCA-8 minutes). After ACCA, all animals received cardiopulmonary resuscitation for 2 minutes and subsequent defibrillation until return of spontaneous circulation (ROSC). The troponin I levels were measured at 4 hours after ROSC. Animals died spontaneously or were killed at 72 hours after ROSC. The hippocampus were removed and fixed in 3% formalin. TdT-mediated dUTP-biotin nick end labeling and Nissl stainings were performed in 10-μm thickness coronal sections. Furthermore, two rabbits (without induction of ventricular fibrillation, cardiopulmonary resuscitation, and defibrillation) served as normal control group.

RESULTS

Mean survival times after ROSC were 48.57 hours ± 24.70 hours, 18.0 hours ± 15.13 hours, and 3.88 hours ± 2.39 hours for groups ACCA-3 minutes, ACCA-5 minutes, and ACCA-8 minutes, respectively. Survival was significantly different between ACCA-3 minutes and other two groups (p = 0.002 and p = 0.01). Neuronal necrosis and apoptosis were found in the hippocampus CA1, CA2, and CA3 areas of group ACCA-3 minutes. In contrast, neuronal necrosis and TdT-mediated dUTP-biotin nick end labeling positive cells were fewer in control animals.

CONCLUSIONS

The rabbits in group ACCA-3 minutes had significant neuronal damage with apoptosis in hippocampus CA1, CA2, and CA3 areas at 72 hours after ROSC and survived longer than those in other groups. The model we describe may be a simple, economic, and reliable model for experimental investigation on cardiopulmonary cerebral resuscitation.

A reproducible model of circulatory arrest and remote resuscitation in rats for NMR investigation

BACKGROUND AND PURPOSE

Because noninvasive physiological monitoring of cerebral blood flow, metabolic integrity, and brain ion and water homeostasis can now be accomplished with new, state-of-the-art MR spectroscopy and imaging techniques, it is appropriate to develop controllable and reproducible animal models that permit prolonged circulatory arrest and resuscitation in the magnet and also allow for studies of long-term survival and outcome. We have developed such a model in rats that involves minimal surgical preparations and can achieve resuscitation remotely within precisely controlled time.

METHODS

Cardiac arrest was induced by asphyxiation, the duration of which ranged from 8 to 24 minutes. Resuscitation was achieved remotely by a slow, intra-aortic infusion of oxygenated blood (withdrawn either from the same rat before asphyxia or from a healthy donor rat) along with a resuscitation cocktail containing heparin (50 U/100 g), sodium bicarbonate (0.1 mEq/100 g), and epinephrine (4 micrograms/100 g). The body temperature was measured by a tympanic thermocouple probe and was controlled either by a heating pad (constant tympanic temperature = 37 degrees C) or by warm ambient air (constant air temperature = 37 degrees C). Interleaved 31P/1H nuclear magnetic resonance (NMR) spectroscopy was used in a selected group of rats to measure the cerebral metabolism before and during approximately 20 minutes of circulatory arrest and after resuscitation.

RESULTS

The overall success rate of resuscitation, irrespective of the duration of cardiac arrest, was 82% (51 of 62). With a programmed infusion pump, the success rate was even higher (95%). The survival time for rats subjected to 15 and 19 minutes of asphyxia with core temperature tightly controlled was significantly lower than that with ambient temperature control (P < 0.001 and P < 0.04, respectively). High-quality NMR spectra can be obtained continuously without interference from the resuscitation effort. Final histological examinations taken 5 days after resuscitation showed typical neuronal damages, similar to those found in other global ischemia models.

CONCLUSIONS

Because the no-flow time and resuscitation time can be precisely controlled, this outcome model is ideally suited for studies of ischemic and reperfusion injuries in the brain and possibly in other critical organs, permitting continuous assessment of long-term recovery and follow-up in the same animals.