Regionalization of critical care medicine: task force report of the American College of Critical Care Medicine.

OBJECTIVES: To review the existing literature and task force opinions on regionalization of critical care services, and to synthesize a judgement on possible costs, benefits, disadvantages, and strategies. DATA SOURCES: Pertinent literature in the English language. STUDY SELECTION: One hundred forty-six English language papers were studied to determine possible ramifications of regionalization of critical care or other similar services. DATA EXTRACTION: Information on possible influence on the care of the critically ill was sought and integrated with the opinions of task force members. Possible costs, benefits, as well as disadvantages to the patient, transferring and receiving institutions, and region as a whole were sought. DATA SYNTHESIS: Regionalization of critical care services was thought to be advantageous to the patient. The larger academic institutions tend to have more resources, better subspecialty availability, and expertise in the care of the critically ill. Efficiency and safety during transport need to be in place. Disadvantages of overutilization, possible costliness to both the referring institution as well as to the receiving institution were outlined. It was agreed that pediatric critical care medicine was a separate issue. CONCLUSIONS: Regionalization of critical care medicine probably is beneficial and the concept should be explored.

MRI protocol for critically ill patients.

BACKGROUND Ventilators compatible with magnetic resonance imaging machines are not universally available. However, the lack of such equipment should not preclude magnetic resonance imaging. We have developed a method by which a critically ill patient requiring mechanical ventilation can safely undergo such imaging without compatible equipment. METHOD By using extended ventilator tubing and calculating volume lost due to tubing compliance, safe and reliable mechanical ventilation can be achieved from a distance without impairing scan quality. RESULTS We devised a method to calculate volume lost due to mechanical compliance of the tubing with ventilator circuits employing 20, 30, and 50 feet of tubing. We added the estimated loss of volume to the set tidal volume of 700 mL to give a delivered volume of 700 mL. Twenty breaths were evaluated for each length of tubing. The evaluation of the 20- and 30-foot lengths of tubing demonstrated 10- and 52-mL discrepancies, respectively, between predicted and measured volumes. The 50-foot length showed a 121-mL discrepancy between predicted and measured volumes. CONCLUSIONS Our method appears to be clinically accurate for predicting volume lost due to tubing compliance for lengths of ventilator tubing less than or equal to 30 feet. We have found this technique to be a safe and effective way to ensure patient safety and scan quality in patients requiring mechanical ventilation during magnetic resonance imaging.

Regionalization and categorization of critical care services.

Regionalized systems of care match the medical needs of individual patients to available resources. Hospitals are categorized based on their personnel and technologic resources. Triage guidelines, based on severity of disease, are developed to link patient types to hospital categorization levels. Regionalization requires major planning, publicity, and educational efforts to implement an ongoing coordination and continuous quality improvement to function.

In-hospital cardiac arrest.

Patients who suffer an in-hospital cardiac arrest represent a neglected and underutilized resource for resuscitation research. There exists an unwritten, but widely held, belief among resuscitation researchers that the in-hospital arrest population is unsuitable for resuscitation research because it is composed mostly of patients whose cardiac arrest is the terminal event of a fatal illness. Despite the large numbers of hospitalized patients on whom cardiac resuscitation is attempted each year, there are few reports and even less true research devoted to this clinical problem. This article, which is intended to be provocative, reviews and summarizes the existing literature on in-hospital resuscitation from cardiac arrest, considers the advantages of resuscitation research in this setting, and concludes with a challenge to resuscitation researchers.

A nurse-directed protocol using pulse oximetry to wean mechanically ventilated patients from toxic oxygen concentrations.

The usual method of weaning mechanically ventilated patients from high FIO2 in our ICU, in which housestaff ordered all ventilator changes in an unstandardized manner (control group), was compared to a nurse-directed protocol that used a single arterial blood gas (ABG) analysis and multiple pulse oximetry measurements. The protocol required an ABG to be obtained upon the initiation of intubation/mechanical ventilation, followed by pulse oximetry measurements obtained in accordance with a standardized timetable. Decreases in FIO2 were guided by these results. It was concluded that a nurse-directed oxygen weaning protocol utilizing a combination of a single ABG and multiple pulse oximetry measurements was safe, reduced the need for ABGs, and decreased the duration of patient exposure to toxic oxygen concentrations.

Effect of ibuprofen in patients with severe sepsis: a randomized, double-blind, multicenter study. The Ibuprofen Study Group.

OBJECTIVE: To evaluate the safety and physiologic actions of ibuprofen in patients with severe sepsis. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Three university hospital medical ICUs. PATIENTS: Twenty-nine patients with clinical evidence of sepsis and the need for hemodynamic monitoring with a pulmonary artery flotation catheter. INTERVENTIONS: Thirteen patients received placebo and 16 received ibuprofen that consisted of 600 mg (n = 11) or 800 mg (n = 5) iv over 20 mins, followed by three 800-mg doses administered as a rectal solution every 6 hrs. The initial iv dose was given within 4 hrs of the presumptive diagnosis of sepsis. MEASUREMENTS AND MAIN RESULTS: The peak circulating total ibuprofen concentration after the iv dose (49.4 +/- 4.5 micrograms/mL, mean +/- SEM) was higher than peak concentrations after the three rectal doses (17.0 +/- 2.7, 16.4 +/- 3.0, 16.0 +/- 3.1 micrograms/mL). Both routes of ibuprofen administration were well tolerated. Frequent monitoring for gastrointestinal bleeding and assessment of renal and hepatic function failed to demonstrate significant differences between ibuprofen and placebo. Because a trend for reduced creatinine clearance was observed at 8 hrs in the ibuprofen group, nephrotoxicity of this drug in sepsis cannot be excluded. Temperature decreased significantly within 4 hrs of the initial dose of investigational therapy in patients who received ibuprofen (38.5 +/- 0.3 degrees to 37.0 +/- 0.2 degrees C, p less than .001). However, despite this significant change in temperature, we were unable to detect significant differences in hemodynamic and respiratory values or survival when ibuprofen-treated patients were compared with controls. CONCLUSIONS: Ibuprofen was well tolerated when administered iv and rectally to patients with severe sepsis, although drug absorption was poor with the rectal route. Significant antipyretic effects of ibuprofen were demonstrated. Although an excellent safety profile characterized ibuprofen in this study, the absence of ibuprofen-associated toxicity may have been secondary to poor rectal absorption of the drug. Our results support the continued clinical investigation of ibuprofen in sepsis, using an all-intravenous route of administration.

Relieving overcrowded emergency departments through ambulance diversion.

One city's solution to overcrowded emergency departments and a shortage of beds was the installation of an ambulance-diversion system, whereby ambulances carrying patients with relatively minor injuries were diverted, when necessary, from the city's busy emergency departments to less crowded ones in neighboring counties.

Pharmacokinetics of a 3 mg/kg body weight loading dose of gentamicin or tobramycin in critically ill patients.

We evaluated the pharmacokinetics and adequacy of gentamicin or tobramycin after administration of a loading dose of 3 mg/kg body weight in 14 critically ill patients with presumed sepsis. Therapeutic blood levels after loading dose were obtained in 13 of the 14 patients. Measured volume of distribution, serum half-life, and elimination rate constant were significantly different from values calculated by using standard formulae. All the patients tolerated the dose well without significant deterioration in renal function. Based on the present study, we conclude that administration of 3 mg/kg body weight loading dose of gentamicin or tobramycin in critically ill patients with sepsis would result in earlier therapeutic drug levels.

Analysis of the effects of continuous on-line monitoring of mixed venous oxygen saturation on patient outcome and cost-effectiveness.

Continuous measurement of mixed venous oxygen saturation (Sv-O2) has recently been introduced as a monitoring and management technique in critical care patients. To determine the impact of Sv-O2 monitoring on patient management and cost-effectiveness, we conducted a prospective, randomized clinical trial of 99 consecutive patients receiving pulmonary artery (PA) catheters in the ICU. One group (n = 49) received an Edwards quadruple-lumen flow-directed PA catheter. Another group (n = 50) received the Oximetrix Opticath, a flow-directed PA catheter utilizing reflective fiberoptic oximetry for continuous Sv-O2 monitoring. Data recorded included APACHE and TISS scores, duration of stay, number of catheter days, incidence of catheter problems and changes, number of blood gases (arterial and venous), and ICU mortality. Additionally, the early warning capability of Sv-O2 monitoring was analyzed by comparing the severity and outcome of potentially adverse hemodynamic events in both groups. Statistical analysis by step-deletion multiple regression analysis and the unpaired Student's t-test demonstrated that use of the Opticath was not associated with a decrease in potentially adverse hemodynamic events, length of ICU stay, or mortality. In terms of cost-effectiveness, mixed venous oximetry is economically favorable in a charge-based reimbursement system, but economically unfavorable in a fixed-cost-based reimbursement system. Although continuous Sv-O2 monitoring has been shown to be accurate and reliable, it does not appear to be beneficial in all patients requiring PA catheterization.

Bilateral optic atrophy after cardiac arrest in a patient with acute respiratory failure on positive pressure ventilation.

Bilateral blindness resulting from optic atrophy is an unusual complication following shock and cardio-respiratory arrest. This report describes a patient with acute respiratory failure due to pneumococcal pneumonia being treated with very high levels of positive end expiratory pressure who developed bilateral blindness following cardiac arrest. This unfortunate complication most likely resulted from increased intraocular pressure and low systemic perfusion pressure synergistically causing ischemia of the optic nerves.

Spontaneous dissection of the cervical internal carotid artery: correlation of arteriography, CT, and pathology.

Spontaneous dissection of the internal carotid artery is being recognized as a more frequent cause of acute neurologic deficit, particularly in young persons. Saccular pseudoaneurysm formation may be an associated finding, especially in the presence of tortuosity (coiling) of the cervical internal carotid artery. Of eight patients with nine vessels demonstrating internal carotid artery dissection on arteriography, pseudoaneurysms were found in five arteries. Four of the five pseudoaneurysms occurred in tortuous (coiled) arterial segments. Thin-section contrast-enhanced dynamic incremental CT showed close agreement with the findings on selective arteriography and provided additional information on the presence and configuration of arterial wall thickening as well as the extent of the pseudoaneurysm. Our experience indicates that CT may play an important role in the diagnosis, management, and follow-up of this lesion.

Stabilization of patients prior to interhospital transfer.

With regionalization of specialized health care services, some patients must be transferred between hospital to receive needed care. The authors evaluated 100 transfers to their emergency department as to the adequacy of stabilization prior to transport. Problems were identified in the areas of communication (nine cases), oxygenation (two cases), cardiac monitoring (one case), intravenous lines (eight cases), airway (two cases), ventilation (one case), equipment and personnel accompanying the patient (one case), bladder catheterization (four cases), nasogastric suctioning (one case), radiographs (nine cases), and spinal immobilization (seven cases). Because more than one error occurred in some patients, the total number of patients having problems with stabilization was 28. The authors also compared the reimbursement status of transferred patients with that of the region's and emergency department's patient populations. No evidence was found that financially undesirable patients were being preferentially transferred. Thus, even when transfers are not made because of unfavorable reimbursement status, many errors in stabilization occur. A review of the literature shows that inadequacies in stabilization for transfer are widespread. This may be improved through physician education, use of transport teams, and judicious use of interhospital transport. The indications and responsibilities of transfer are discussed.

Air embolism and cardiac arrest in a patient with a pulmonary artery catheter: a possible association.

This patient with acute mitral insufficiency suddenly developed hemoptysis and electromechanical dissociation. A post mortem chest X-ray demonstrated a large amount of air in the right ventricular cavity. It is postulated that this air embolism resulted from a catheter-induced rupture of the pulmonary artery.

External cardiac pacing for out-of-hospital bradyasystolic arrest.

Cardiac pacing has been used successfully in patients with asystole or bradycardia compromising hemodynamics when it was applied soon after the onset of the event. An external cardiac pacemaker was used as part of initial resuscitative efforts for patients in primary, out-of-hospital, cardiac arrest who arrived in the emergency department in asystole, agonal rhythm, pulseless idioventricular rhythm, or bradycardia with hemodynamic compromise. A pulse was successfully generated in only one of twelve patients. That patient developed complete atrioventricular dissociation while in the emergency department. The nonresponding patients were in asystole or pulseless idioventricular rhythm when the pacemaker was applied. Pacing was initiated 1-13 minutes (mean 7 minutes) after arrival in the emergency department, but 27-90 minutes (mean 59 minutes) after arrest. The interval between arrest and application of the pacemaker was prolonged because of long periods for ambulance response, field resuscitation, and transport. It is concluded that the external cardiac pacemaker is a useful instrument for the treatment of bradyarrhythmias. While it may also be useful in the first few minutes after development of asystole, pulseless idioventricular rhythm, or agonal rhythm, it is of no benefit if applied long after the event.