The maximal duration of cardiopulmonary resuscitation (CPR) is unknown. We report a case of prolonged CPR. We have then reviewed all published cases with CPR duration equal to or more than 20 minutes. The objective was to determine the survival rate, the neurological outcome, and the characteristics of the survivors.
Cardiopulmonary resuscitation (CPR) using closed-chest cardiac massage technique was first used in 1960 by Kouwenhoven in 17 patients with cardiac asystole and 3 patients with ventricular fibrillation, with a successful resuscitation in 14 patients (70%) [
In this paper we describe a case of prolonged resuscitation with successful outcome. Since there is no randomized trials that have evaluated the duration of resuscitation and the bulk of information regarding the duration of resuscitation in various conditions such as hypothermia relies on case series and expert opinion, we reviewed all reported cases of prolonged resuscitation in the English literature. Our goal was to determine the success rate and neurological outcome of these patients and to define the characteristics of patients who might benefit from such heroic measures.
A 76-year-old African American man was admitted to the orthopedics service with a right midtibial fracture. He has a past medical history of diabetes, anemia, obstructive sleep apnea, hypertension, and osteoarthritis. He was taken to the operating room (OR) for open reduction and internal fixation under general anesthesia with endotracheal intubation and sciatic nerve block. Pulse oximetry, end tidal CO2 (ETCO2), bispectral index (BIS), and arterial line blood pressure were continuously monitored. Patient received intravenous midazolam and fentanyl and was paralyzed with cisatracurium.
During the procedure, he was in sinus rhythm with heart rate of 120 per minute, blood pressure was 136/71, and temperature was 36.2°C, with FiO2 of 0.6 with O2 saturation of 98%, ETCO2 of 37 mmHg, and BIS ranging from 39 to 48 during the entire procedure.
After three and half hours of general anesthesia, the tourniquet was released, and immediately the blood pressure dropped to 50/30 mmHg, the heart rate decreased to 20 beats per minute, O2 saturation dropped to 80, and the ETCO2 dropped to 7 mmHg. The patient became pulseless and CPR was immediately started. The initial rhythm was pulseless electrical activity (PEA). Epinephrine and vasopressin were given intravenously. Acute massive pulmonary embolism was suspected. Aspiration from left internal jugular central line was done for possible air embolism. Emergent transesophageal ultrasound was performed and showed a dilated right ventricle, with poor systolic function, and hyperdynamic left ventricle. Heparin bolus of 10,000 units was administered. Systemic thrombolytic therapy was contraindicated with the open leg wound. Despite resuscitation for 20 minutes, the patient remained in PEA. The catheterization lab was activated to attempt percutaneous embolectomy. CPR was continued en route with continuous ETCO2 monitoring which was maintained above 20 mmHg. Multiple providers switched every 2-3 minutes to maintain good quality chest compression, as measured by the end tidal CO2. Upon arriving in the catheterization laboratory the patient had return of spontaneous circulation (ROSC) to normal sinus rhythm. Total CPR duration was 86 min during which the rhythm remained PEA. No cardioversion was performed. Medications given during CPR included 5 mg of epinephrine followed by a drip at 50 micrograms/min, 40 units of vasopressin, 2 mg of atropine, 100 meq (100 mmol) of bicarbonate, and 2 gm (13.6 mmol) of calcium chloride for low ionized calcium level (1.09 mmol/L, normal in our lab is greater than 1.12 mmol/L). Bicarbonate was given due to the concern for severe acidosis in the context of prolonged PEA (pH down to 6.9 during the code). BIS was continuously monitored and remained above 80 during the entire resuscitation.
Pulmonary angiogram revealed multiple bilateral distal pulmonary emboli. No saddle or proximal pulmonary artery emboli were seen. A retrievable inferior vena cava filter was placed and patient was transferred to the intensive care unit. Following return from the cath lab, therapeutic hypothermia was instituted given persistent Glasgow coma scale of 8. A temperature of 33°C was targeted. This was maintained for 24 h, followed by a gradual rewarming (0.25°C/hour). In addition, he was anticoagulated with a heparin drip after local hemostasis was achieved at the bedside by the orthopedic surgeons. After 24 hours, the patient was rewarmed. He was successfully extubated 2 days later. He returned to neurologic baseline with normal cognition over the next several days. He was transitioned to Coumadin and was discharged home.
The decision to continue CPR beyond 20 minutes was based on the observed nature of the arrest, the availability of a large number of staff to sustain good quality CPR demonstrated by ETCO2 monitoring, and the persistence of a high BIS score suggesting persistent brain activity.
We performed a PubMed search of “Prolonged Resuscitation” of all published articles from 1947 to 2013. 3,826 publications were found. Subsequent filters applied included the following: “Human Species”, “Case reports”, “Abstract”, and “English language”. 491 articles met the above criteria and were obtained by online access and through interlibrary loan. All 491 articles were reviewed by 2 pulmonary and critical care physicians. Articles were included in this study if they included a detailed description of the resuscitative effort during cardiac arrest (such as immediate cause of arrest, latency to chest compression, duration of chest compression, amount of defibrillation, and number of returns of spontaneous circulation), if such effort lasted at least 20 minutes and if there was a description of the outcome including death or neurological status.
We identified 71 case reports published describing prolonged resuscitation after cardiac arrest. Some of the reports had more than 1 patient, and therefore a total of 82 patients are included in our review. All cases were published between 1980 and 2013 [
The baseline characteristics of the patients are listed in Table
Baseline characteristics of the 82 patients.
Baseline characteristics |
|
Age (years) | |
Mean (SD) | 43 ± 21 |
Median (range) | 42 (0.1–88) |
Gender, M/F | 46/36 |
Location, |
|
Inpatient | 40 (49) |
Outpatient | 42 (51) |
Preexisting disorders, |
|
HTN | 7 (9) |
Diabetes mellitus | 7 (9) |
Cardiovascular disease | 13 (16) |
Chronic renal insufficiency | 5 (6) |
Malignancy | 5 (6) |
Cerebrovascular disease | 1 (2) |
Cause of the arrest, |
|
Acute myocardial infarction | 24 (29) |
Hypothermia | 17 (21) |
Pulmonary emboli | 10 (12) |
Arrhythmia | 6 (7) |
Drug overdose | 5 (6) |
Hyperkalemia | 4 (5) |
Myocarditis | 3 (4) |
Drowning | 2 (2) |
Diabetic ketoacidosis | 2 (2) |
Postelectroconvulsion therapy | 1 (1) |
Anaphylactic shock | 1 (1) |
Electric shock | 1 (1) |
Hemorrhagic shock | 1 (1) |
Drug induced paralysis | 1 (1) |
Abdominal aneurysm rupture | 1 (1) |
Cardiomyopathy | 1 (1) |
Amniotic fluid embolism | 1 (1) |
Lidocaine toxicity | 1 (1) |
The latency to CPR had an average duration of 2 ± 6 minutes (Table
Characteristics of the cardiac arrests.
EKG rhythm at the beginning of CPR, |
|
Ventricular fibrillation | 32 (39) |
Ventricular tachycardia | 9 (11) |
Asystole | 21 (26) |
Pulseless electrical activity | 16 (20) |
Torsade de pointes | 1 (1) |
Latency to CPR (minutes) | |
Mean (SD) | 2.0 ± 6 |
Median (range) | 0 (0–40) |
Duration of (CPR) (minutes) | |
Mean (SD) | 97.5 ± 74.8 |
Median (range) | 75 (20–330) |
Quality of chest compression, |
|
Good | 49/51 (96) |
Interrupted | 1/51 (2) |
Mechanical chest compression | 6/51 (12) |
Defibrillation, |
|
Mean (SD) | 6.8 ± 13.5 |
Median (range) | 3 (0–99) |
Number of return of spontaneous circulation (ROSC) | |
Mean (SD) | 1.2 ± 0.6 |
Median (range) | 1 (0–3) |
Duration of the cardiopulmonary resuscitation in the 82 patients.
Several types of adjunct therapies were used (Table
Use of adjunct therapy.
ECMO | |
Patients in whom ECMO was used without | 15 |
a pulse, | |
Duration of ECMO without pulse | |
Mean in minutes (SD) | 3929 ± 5738 |
Median (range) | 55 (3 minutes–11 days) |
Total duration of ECMO usage (days) | |
Mean (SD) | 4.5 ± 3.9 |
Median (range) | 3.5 (1–11) |
Thrombolysis, |
13 (15.8) |
Thrombolysis for pulmonary emboli | 9 |
Thrombolysis for acute myocardial infarction | 3 |
Thrombolysis for refractory arrhythmia | 1 |
Stent placement, |
9 (11) |
Stent placement during cardiac arrest | 1 |
Stent placement after ROSC | 8 |
Rewarming in the 17 patients with hypothermia, |
16 |
Hypothermia after ROSC, |
13 |
Open cardiac massage, |
3 (3.6) |
Cardiac pacing, |
8 (9.7) |
Amputation of ischemic leg, |
1 (1.2) |
ECMO: extracorporeal membrane oxygenation.
ROSC: return of spontaneous circulation.
Post-ROSC complications (Table
Prolonged CPR related complications after prolonged resuscitation.
Respiratory |
22 |
Pulmonary edema | 15 |
Pneumonia | 7 |
Pneumothorax | 2 |
Hemothorax | 1 |
Rib fracture | 4 |
Renal failure, |
15 |
Low ejection fraction, |
7 |
Neurological, |
|
Intracranial hemorrhage | 3 |
Ischemic stroke | 1 |
Seizure | 5 |
Bleeding disorders, |
4 |
Rhabdomyolysis, |
4 |
Liver hematoma, |
2 |
Deformation of aortic valve, |
1 |
Colon ischemia, |
1 |
Interestingly, signs of life during CPR were reported in 10 cases (12%). These signs were present without evidence of spontaneous circulation and included making respiratory efforts [
Five patients (6%) did not recover after resuscitation. At 28 days, 13 patients were dead (16%). At 6 months, there was one additional death. No patient died between 6 and 12 months. The success rate of these resuscitation cases at 1 year was 68/82 (83%).
At 1 year, 50 patients (61%) had full neurological recovery, 14 patients (17%) had a good cerebral performance defined as a cerebral performance category (CPC) of one [
Studies of the effect of the duration of resuscitation on clinical outcome are few. A recent retrospective analysis of out-of-hospital cardiac arrests showed a decrease in the probability of survival to hospital discharge with a good functional outcome with each minute of cardiopulmonary resuscitation. The probability of good functional outcome after 15 minutes of CPR was down to 2%, compared to 75% for patients resuscitated for 10–15 minutes [
Based on these studies, it appears that the need for longer resuscitation is associated with worse outcome. On the other hand, in a review by Goldberger, longer duration of resuscitation was associated with a higher survival rate, especially in patients with an initial rhythm of PEA or asystole [
Our reported and reviewed cases describe a unique group of patients that received cardiopulmonary resuscitation for a duration that far exceeded the average. In fact, the median CPR duration was 75 minutes, compared to an average of 17 minutes for in-hospital cardiac arrest [
A major drawback in our study is the presence of publication bias. Positive results’ bias occurs when authors are more likely to submit, or editors accept, positive compared to negative or inconclusive results cases [
Physicians are frequently responsible for determining the maximal duration of resuscitation for each patient. We do not believe that an absolute duration of CPR is adequate for all patients. Rather, physicians should base the decision to continue CPR on several factors that affect the chances of survival after cardiac arrest. These factors include the patient baseline status, coexisting comorbidities, latency to CPR, latency to defibrillation, and adequacy of chest compression which should be monitored with ETCO2 and/or diastolic blood pressure [
Cerebral perfusion is the goal for CPR. BIS has been used to monitor the hypnotic state in the operating room and to titrate sedation in the ICU [
Even though BIS can artificially be increased by movement artifact such as chest compression [
While there is no proven correlation between BIS monitoring and neurological outcome after CPR, our case report shows its potential benefit; we believe that a high level should be encouraging to the team to continue their effort as it reflects adequate perfusion; however a low level is more difficult to interpret.
The underlying disease causing the cardiac arrest can significantly affect the outcome of the resuscitation. Of all etiologies, four specific diagnoses constituted 67% of all reviewed cases. These are acute myocardial infarction, hypothermia, pulmonary emboli, and drug overdose. These etiologies should deserve special consideration by the treating physician for prolongation of CPR duration as well as other adjunctive therapies such as ECMO. In fact out-of-hospital cardiac arrests of cardiac origin have been associated with a better outcome compared to those of noncardiac origin [
ECMO may improve outcome after cardiac arrest when compared to standard CPR [
An interesting finding was the presence of signs of life in the absence of spontaneous pulse. These signs ranged from spontaneous respiratory effort to following commands while receiving chest compression. These signs disappeared when CPR was withheld to evaluate for ROSC. This could be explained by good CPR quality leading to a sufficient brain perfusion. In such cases, it is important to continue good resuscitative effort and minimize CPR interruption. Spontaneous pulse should only be checked at the recommended frequency to minimize brain injury from hypoperfusion.
Our review suggests that the decision to continue or stop CPR should not be based solely on the duration of resuscitation. Factors that affect the outcome include the patient’s baseline condition, the reversibility of the cause of the arrest, the latency to starting CPR, the quality of CPR, and the availability and expertise in ECMO. It is possible to encounter signs of life during CPR which should be interpreted as evidence of good perfusion to an intact brain. It is important not to interpret these signs as evidence of ROSC and to minimize any interruption in chest compression.
Drs. Houssein Youness and Ahmed Awab were involved in the conception and design of the study. Drs. Tarek Al Halabi and Houssein Youness were involved with data acquisition. Drs. Jean Keddissi and Houssein Youness were involved in the statistical analysis and interpretation of the data. Dr. Houssein Youness was involved in the drafting of the paper. Drs. Jean Keddissi, Ahmed Awab, Hussein Hussein, and Kellie Jones were involved in the revision of the paper.
The authors of this paper have no conflict of interests to disclose.