Ultrarapid Induction of Hypothermia Using Continuous Automated Peritoneal Lavage With Ice-Cold Fluids: Final Results of the Cooling for Cardiac Arrest or Acute ST-Elevation Myocardial Infarction Trial.

OBJECTIVES: Hypothermia (32-34 °C) can mitigate ischemic brain injury, and some evidence suggests that it can reduce infarct size in acute myocardial infarction and acute ischemic stroke. For some indications, speed of cooling may be crucial in determining efficacy. We performed a multicenter prospective intervention study to test an ultrarapid cooling technology, the Velomedix Automated Peritoneal Lavage System using ice-cold fluids continuously circulating through the peritoneal cavity to rapidly induce and maintain hypothermia in comatose patients after cardiac arrest and a small number of awake patients with acute myocardial infarction. DESIGN: Multicenter prospective intervention study. SETTING: Intensive care- and coronary care units of multiple tertiary referral centers. MEASUREMENTS AND MAIN RESULTS: Access to the peritoneal cavity was gained using a modified blunt dilating instrument, followed by catheter placement. Patients were cooled to a temperature of 32.5 °C, maintained for 24 hours (cardiac arrest) or 3 hours (acute myocardial infarction) followed by controlled rewarming. Forty-nine patients were enrolled, and 46 patients completed treatment. One placement was unsuccessful (abdominal wall not breached), two patients were ultimately not cooled, and only safety data are reported. Average catheter insertion time was 2.3 minutes. Mean time to temperature less than 33 °C was 10.4 minutes (average cooling rate, 14 °C/hr). Median infarct size in patients who had coronary interventions was 16% of LV. No cases of stent thrombosis occurred. Survival in cardiac arrest patients with initial rhythm of ventricular tachycardia/ventricular fibrillation was 56%, of whom 82 had a complete neurologic recovery. This compares favorably to outcomes from previous studies. CONCLUSION: Automated peritoneal lavage system is a safe and ultrarapid method to induce and maintain hypothermia, which appears feasible in cardiac arrest patients and awake patients with acute myocardial infarction. The shivering response appeared to be delayed and much reduced with this technology, diminishing metabolic disorders associated with cooling and minimizing sedation requirement. Our data suggest that ultrarapid cooling could prevent subtle neurologic damage compared with slower cooling. This will need to be confirmed in direct comparative studies.

Automated peritoneal lavage: an extremely rapid and safe way to induce hypothermia in post-resuscitation patients.

INTRODUCTION: Mild therapeutic hypothermia (MTH) is a worldwide used therapy to improve neurological outcome in patients successfully resuscitated after cardiac arrest (CA). Preclinical data suggest that timing and speed of induction are related to reduction of secondary brain damage and improved outcome. METHODS: Aiming at a rapid induction and stable maintenance phase, MTH induced via continuous peritoneal lavage (PL) using the Velomedix Inc. automated PL system was evaluated and compared to historical controls in which hypothermia was achieved using cooled saline intravenous infusions and cooled blankets. RESULTS: In 16 PL patients, time to reach the core target temperature of 32.5°C was 30 minutes (interquartile range (IQR): 19 to 60), which was significantly faster compare to 150 minutes (IQR: 112 to 240) in controls. The median rate of cooling during the induction phase in the PL group of 4.1°C/h (IQR: 2.2 to 8.2) was significantly faster compared to 0.9°C/h (IQR: 0.5 to 1.3) in controls. During the 24-hour maintenance phase mean core temperature in the PL patients was 32.38 ± 0.18°C (range: 32.03 to 32.69°C) and in control patients 32.46 ± 0.48°C (range: 31.20 to 33.63°C), indicating more steady temperature control in the PL group compared to controls. Furthermore, the coefficient of variation (VC) for temperature during the maintenance phase was lower in the PL group (VC: 0.5%) compared to the control group (VC: 1.5%). In contrast to 23% of the control patients, none of the PL patients showed an overshoot of hypothermia below 31°C during the maintenance phase. Survival and neurological outcome was not different between the two groups. Neither shivering nor complications related to insertion or use of the PL method were observed. CONCLUSIONS: Using PL in post-CA patients results in a rapidly reached target temperature and a very precise maintenance, unprecedented in clinical studies evaluating MTH techniques. This opens the way to investigate the effects on neurological outcome and survival of ultra-rapid cooling compared to standard cooling in controlled trials in various patient groups. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01016236

Tracheobronchomalacia due to amyloidosis in a patient with rheumatoid arthritis.

In this case report, we describe a patient with longstanding rheumatoid arthritis who developed tracheobronchomalacia with fatal outcome. Despite negative antemortem biopsies of abdominal fat and tongue, amyloid was found postmortem in the trachea and appeared to be associated with tracheobronchomalacia.