Joseph C. Stothert

Effectiveness and safety of the awakening and breathing coordination, delirium monitoring/management, and early exercise/mobility bundle.

Objective:The debilitating and persistent effects of ICU-acquired delirium and weakness warrant testing of prevention strategies. The purpose of this study was to evaluate the effectiveness and safety of implementing the Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle into everyday practice. Design:Eighteen-month, prospective, cohort, before-after study conducted between November 2010 and May 2012. Setting:Five adult ICUs, one step-down unit, and one oncology/hematology special care unit located in a 624-bed tertiary medical center. Patients:Two hundred ninety-six patients (146 prebundle and 150 postbundle implementation), who are 19 years old or older, managed by the institutions’ medical or surgical critical care service. Interventions:Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle. Measurements and Main Results:For mechanically ventilated patients (n = 187), we examined the association between bundle implementation and ventilator-free days. For all patients, we used regression models to quantify the relationship between Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle implementation and the prevalence/duration of delirium and coma, early mobilization, mortality, time to discharge, and change in residence. Safety outcomes and bundle adherence were monitored. Patients in the postimplementation period spent three more days breathing without mechanical assistance than did those in the preimplementation period (median [interquartile range], 24 [7–26] vs 21 [0–25]; p = 0.04). After adjusting for age, sex, severity of illness, comorbidity, and mechanical ventilation status, patients managed with the Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle experienced a near halving of the odds of delirium (odds ratio, 0.55; 95% CI, 0.33–0.93; p = 0.03) and increased odds of mobilizing out of bed at least once during an ICU stay (odds ratio, 2.11; 95% CI, 1.29–3.45; p = 0.003). No significant differences were noted in self-extubation or reintubation rates. Conclusions:Critically ill patients managed with the Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle spent three more days breathing without assistance, experienced less delirium, and were more likely to be mobilized during their ICU stay than patients treated with usual care.

Randomized prospective evaluation of cimetidine and antacid control of gastric pH in the critically ill

One hundred forty-four critically ill patients admitted to an intensive care setting were randomly assigned to cimetidine or antacid treatment groups. Gastric pH was monitored hourly. One hundred twenty-three (85%) patients demonstrated a fall in pH to <4 and were considered to require prophylaxis. Prophylaxis was considered adequate if the measured pH could then be maintained at ≥4. Fifty-eight patients received antacids alone, the average requirement being 41 cc/hour. Sixty-five patients received cimetidine. Seventeen (26%) of the cimetidine prophylaxis patients failed to raise their pH and were then placed on hourly administration of antacid With successful elevations of pH to ≥4 in all cases on an average supplementary dose of 53 cc/hour. Risk factors, including sepsis, hypotension, head injury, respiratory failure, degree of trauma, and age, were not statistically different in the two treated groups. Using these same criteria, responders to cimetidine could not be differentiated from nonresponders. All patients were protected from significant stress bleeding while on this study. Significant complications of either treatment were minimal. Antacids ottered consistent protection against gastric acidity and were 100% effective. A routine schedule of 300 mg every six hours of cimetidine was effective in only 47% of patients, and the maximum dose of cimetidine was effective in only 74% of patients. Hourly measurement of intragastric pH is required for monitoring the response to prophylaxis of stress bleeding in severely ill patients.

Effects of nitric oxide synthesis inhibition in hyperdynamic endotoxemia

ObjectiveTo investigate the effects of Nω-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthesis, on hemodynamics, gas exchange and oxygen transport in an ovine model of hyperdynamic sepsis. DesignProspective, nonrandomized, controlled study, with repeated measurements. SettingUniversity research laboratory. SubjectsTwenty healthy adult sheep (weighing 20 to 45 kg) were divided into two groups of 12 treated sheep and eight control sheep and studied. InterventionsTwenty awake, chronically instrumented sheep received a continuous infusion of endotoxin (10 ng/kg/min) over 48 hrs. Twenty-four hours after the start of the endotoxin infusion, 12 sheep (treatment group) received a bolus of the nitric oxide synthesis inhibitor Nω-nitro-L-arginine methyl ester (25 mg/kg), while the other eight animals (control group) received the carrier (0.9% NaCl). Measurements and Main ResultsTwenty-four hours after the start of the endotoxin infusion, both groups exhibited a hyperdynamic state with increased cardiac indices, decreased systemic vascular resistance indices, impaired oxygenation, and increased pulmonary shunt fractions. In both groups, oxygen delivery was significantly increased, while oxygen consumption remained virtually unchanged, resulting in a decreased oxygen extraction ratio. In the control group, the significant alterations in systemic hemodynamics, lung function and oxygen transport persisted for the remainder of the study. Administration of Nω-nitro-L-arginine methyl ester normalized cardiac index and systemic vascular resistance index, increased mean arterial blood pressure, and decreased heart rate. Although oxygen delivery significantly decreased after administration of Nω-nitro-L-arginine methyl ester, oxygen consumption did not change, resulting in a normalization of oxygen extraction ratio. Despite a significant reduction of pulmonary shunt fraction, oxygenation did not improve. Pulmonary arterial pressure and pulmonary vascular resistance index showed a peak 2 hrs after administration of the nitric oxide synthesis inhibitor and then tended to decrease. In contrast, the effects of Nω-nitro-L-arginine methyl ester on the systemic circulation persisted for the remainder of the study. ConclusionsThe data support the assumption that augmented nitric oxide production in a major cause of the hemodynamic alterations seen in hyperdynamic endotoxemia. Administration of the nitric oxide synthesis inhibitor Nω-nitro-L-arginine methyl ester normalized the endotoxin-induced hyperdynamic state, but did not impair oxygen consumption, indicating adequate tissue perfusion of metabolically active organs. Inhibition of nitric oxide synthesis may be a therapeutic option in the treatment of hyperdynamic septic patients when conventional therapy fails to maintain a minimum of cardiovascular performance. (Crit Care Med 1994; 22:306–312)

Implementing the 2005 American Heart Association Guidelines improves outcomes after out-of-hospital cardiac arrest

OBJECTIVE The purpose of the study was to determine whether applying highly recommended changes in the 2005 American Heart Association (AHA) Guidelines would improve outcomes after out-of-hospital cardiac arrest. BACKGROUND In 2005, AHA recommended multiple ways to improve circulation during cardiopulmonary resuscitation (CPR). METHODS Conglomerate quality assurance data were analyzed during prospective implementation of the 2005 AHA Guidelines in five emergency medical services (EMS) systems. All EMS personnel were trained in the key new aspects of the 2005 AHA Guidelines, including use of an impedance threshold device. The primary outcome was survival to hospital discharge. Secondary outcomes were return of spontaneous circulation (ROSC), survival by initial cardiac arrest rhythm, and the cerebral performance category (CPC) score at hospital discharge. RESULTS There were 1,605 patients in the intervention group and 1,641 patients in the control group. Demographics, the rate of bystander CPR, and time from the 911 call for help to arrival of EMS personnel were similar between groups. Survival to hospital discharge was 10.1% in the control group versus 13.1% in the intervention group (P = .007). For patients with a presenting rhythm of ventricular fibrillation/ventricular tachycardia, survival to discharge was 20% in controls versus 32.3% in the intervention group (P <.001). Survival to discharge with a CPC classification of 1 or 2 was 33.3% (10/30) in the control versus 59.6% (31/52) in the intervention group (P = .038). CONCLUSIONS Compared with controls, patients with out-of-hospital cardiac arrest treated with a renewed emphasis on improved circulation during CPR had significantly higher neurologically intact hospital discharge rates.

Is emergency department resuscitation of out-of-hospital cardiac arrest victims who arrive pulseless worthwhile?

It is still a common practice to continue unsuccessful field resuscitations in the emergency department (ED) even after prolonged estimated down times. The authors studied patients who arrested in the field and did not regain a pulse before their arrival in the ED to determine if any ever leave the hospital neurologically intact. All cardiac arrests in the urban St Louis area that were brought to our facility over a 2 1/2-year period by advanced life support units (excluding all patients with hypothermia, drug overdose, near drowning, and traumatic cardiac arrest) were reviewed. Of 243 such patients 32 (13%) arrived with a pulse. Twenty-three of these patients were admitted and 10 discharged alive, 7 were neurologically intact. Out of 211 patients who arrived without a pulse, 24 (11%) developed a pulse with further resuscitative efforts in the ED. Eighteen of these patients were admitted but only one was discharged neurologically intact. The only survivor in the group without a pulse arrested while en route to the ED. It is concluded that cardiac arrest victims who arrive in the ED without a pulse on arrival or en route have almost no chance of functional recovery.

The role of autopsy in death resulting from trauma.

This study examined the difference between clinical impressions and autopsy findings in a group of patients dying on a university surgical service after blunt injury, penetrating injury, or thermal burns. Of 215 patients dying between the years 1984 and 1988, 212 were included in this study (autopsy rate, 98.6%). Major discrepancies in clinical diagnosis versus the anatomic diagnosis at autopsy were found to occur in approximately 30% of patients. The incidence of errors in diagnosis which may have impacted on survival in these groups of injured patients was quite low (5.1%). These data support the continued practice of obtaining autopsy in all patients dying from trauma. This information is clinically relevant, and, in todays atmosphere of quality assurance, absolutely necessary for a modern trauma center.

Correlation of end-tidal CO2 to cerebral perfusion during CPR.

STUDY OBJECTIVE A number of studies have demonstrated a correlation between end-tidal carbon dioxide (ETCO2), cardiac output, and return of spontaneous circulation in experimental animals and in patients undergoing closed-chest CPR. Our study attempted to correlate ETCO2 to cerebral blood flow during cardiac arrest. DESIGN Sixteen piglets were anesthetized, intubated, and instrumented for cerebral blood flow studies. An ultrasonic flow probe was placed on both internal carotid arteries for continuous flow measurements. The animal was fibrillated, and closed-chest CPR was begun. Continuous ETCO2 measurements were obtained and compared with simultaneous internal carotid, cardiac output, and cerebral blood flow measurements. MEASUREMENTS AND MAIN RESULTS Correlations between ETCO2 and carotid and cerebral blood flow were determined using Pearsons method. The correlation between ETCO2 and total internal carotid flow was .58 (P = .01, Bonferronis adjusted P = .30). Correlation between ETCO2 and cerebral blood flow was .64 (P = .01, Bonferronis adjusted P = .09). A partial correlation coefficient for ETCO2 versus cardiac output was .70, whereas it was only .30 for ETCO2 versus cerebral blood flow. CONCLUSION Partial correlation coefficients suggest that ETCO2 correlates with cerebral blood flow when changes in cerebral blood flow parallel changes in cardiac output.

From laboratory science to six emergency medical services systems: New understanding of the physiology of cardiopulmonary resuscitation increases survival rates after cardiac arrest.

Objective:The purpose of this study is to: 1) describe a newly discovered mechanism of blood flow to the brain during cardiopulmonary resuscitation using the impedance threshold device in a piglet model of cardiac arrest, and 2) describe the survival benefits in humans of applying all of the highly recommended changes in the 2005 guidelines related to increasing circulation during cardiopulmonary resuscitation, including use of the impedance threshold device, from six emergency medical services systems in the United States. Design:Animal studies prospective trial with each piglet serving as its own control. Historical controls were used for the human studies. Subjects:Piglets and patients with out-of-hospital cardiac arrest. Interventions:Piglets (10–12 kg) were treated with an active (n = 9) or sham (n = 9) impedance threshold device after 6 mins of ventricular fibrillation. Humans were treated with cardiopulmonary resuscitation per the American Heart Association 2005 guidelines and the impedance threshold device. Measurements and Main Results:Animals: The primary endpoint in the piglet study was carotid blood flow which increased from 59 mL/min without an impedance threshold device to 91 mL/min (p = 0.017) with impedance threshold device use. Airway pressures during the chest recoil phase decreased from −0.46 mm Hg to −2.59 mm Hg (p = 0.0006) with the active impedance threshold device. Intracranial pressure decreased more rapidly and to a greater degree during the decompression phase of cardiopulmonary resuscitation with the active impedance threshold device. Humans: Conglomerate quality assurance data were analyzed from six emergency medical services systems in the United States serving a population of ∼3 million people. There were 920 patients treated for cardiac arrest after implementation of the 2005 American Heart Association guidelines, including impedance threshold device use, and 1750 patients in the control group during the year before implementation. Demographics were similar between the two groups. Survival to hospital discharge was 9.3% in the control group versus 13.6% in the intervention group. The odds ratio, 95% confidence interval, and p value were 1.54 (1.19–1.99) and p = 0.0008, respectively. This survival advantage was conferred to patients with a presenting cardiac arrest rhythm of ventricular fibrillation (28.5% vs. 18.0%, p = 0.0008). Conclusions:Use of the impedance threshold device in piglets increased carotid blood flow and coronary and cerebral perfusion pressures and reduced intracranial pressure during the decompression phase of cardiopulmonary resuscitation at a faster rate than controls, resulting in a longer duration of time when intracranial pressures are at their nadir. Patients in six emergency medical services systems treated with the impedance threshold device together with the renewed emphasis on more compressions, fewer ventilations, and complete chest wall recoil had a nearly 50% increase in survival rates after out-of-hospital cardiac arrest compared with historical controls.

Thoracic esophageal and tracheal injury following blunt trauma

A 20-year-old man injured in a motor vehicular accident sustained a nonpenetrating double blowout injury of the upper thoracic esophagus. A simultaneous membraneous rupture of the trachea occurred. Treatment was by operative primary closure. A collective review of blunt upper thoracic esophageal perforations reveals a nearly uniform occurrence of associated tracheal injury.

Primary Repair of Traumatic Aortic Disruption

From 1979 to 1985, 22 patients (18 male) underwent repair of acute traumatic rupture of the aorta. Ages ranged from 15 to 75 years (mean, 35 years). All patients sustained deceleration injuries in automobile accidents. The majority had injuries to multiple systems and evidence of mediastinal widening on routine chest roentgenograms. Aortography confirmed transection in the descending thoracic aorta near the ligamentum arteriosum in 20. Primary repair was achieved in 15 patients; it was performed in the last 10 consecutive patients. Seven patients had repair with a prosthetic graft. Survival was 82%. Postoperative morbidity usually was related to associated injuries. Primary repair of aortic transection can be accomplished in most patients without the use of prosthetic material.