Management of paroxysmal atrioventricular nodal reentrant tachycardia in the critically ill surgical patient.

OBJECTIVES: Paroxysmal atrioventricular nodal reentrant tachycardia is an infrequently encountered supraventricular arrhythmia that continues to present difficult management problems in the critically ill surgical patient. The purpose of this study was to evaluate the efficacy of a new treatment algorithm involving the sequential administration of different classes of antiarrhythmic agents until conversion to sinus rhythm was achieved. DESIGN: Nonrandomized, consecutive, protocol-driven descriptive cohort. SETTING: University hospital surgical and trauma intensive care unit (ICU). PATIENTS: During an 11-month period, we prospectively evaluated all hemodynamically stable patients who sustained new-onset atrioventricular nodal reentrant tachycardia. INTERVENTIONS: Vagal maneuver, followed by the rapid, sequential infusion of antiarrhythmic agents (i.e., adenosine, verapamil, and esmolol, respectively) until the arrhythmia was terminated. MEASUREMENTS AND MAIN RESULTS: Twenty-seven patients (4% of all admissions) were evaluated, including 16 trauma patients (injury Severity Score of 20 +/- 8) and 11 general surgical patients (Acute Physiology and Chronic Health Evaluation II score of 17 +/- 7). Time from ICU admission to onset of atrioventricular nodal reentrant tachycardia was 4.5 +/- 5 days (median 2.5). Arrhythmia termination was achieved in all patients within minutes (mean 13 +/- 10 [SD]). Incremental sequential adenosine administration alone, however, was successful in affecting conversion to sinus rhythm in only 44% of initial episodes of atrioventricular nodal reentrant tachycardia (95% confidence interval 21% to 67%). A total of 14 (52%) patients developed 38 relapses of paroxysmal supraventricular tachycardia in the ICU after initial conversion to sinus rhythm. These relapses required additional antiarrhythmic therapy. Adenosine was only effective in 34% of the relapses (95% confidence interval 17% to 53%). Seven (50%) of these 14 patients developed multiple relapses. However, only two patients were receiving suppressive calcium-channel or beta-adrenergic receptor blockade at the time of relapse. CONCLUSIONS: The use of a multiagent algorithm was effective for the initial conversion of new-onset atrioventricular nodal reentrant tachycardia to sinus rhythm in critically ill surgical and trauma patients. This preliminary report suggests that adenosine has marginal efficacy in the critically ill surgical or trauma patient. Given the high frequency of relapses, regardless of the agents used to achieve initial control, suppression therapy for the arrhythmia during the period of maximal cardiovascular stress is essential.

Stab wounds to the back and flank in the hemodynamically stable patient: a decision algorithm based on contrast-enhanced computed tomography with colonic opacification.

PURPOSE: The authors wanted to determine whether contrast-enhanced computed tomography (CE-CT) with colonic opacification is an accurate tool to triage hemodynamically stable victims of stab wounds to the flank and back. PATIENTS AND METHODS: One hundred forty-five consecutive patients were categorized as low-risk ( penetration superficial to the deep fascia) or high-risk (penetration beyond the deep fascia) based on CE-CT findings. RESULTS: There were no significant differences in admission vital signs, Glasgow Coma Scale, or complete blood counts between low- and high-risk groups. None of the 92 low-risk patients required surgery or had sequelae. Six of the 53 high-risk patients underwent surgery, 2 based on initial CE-CT, 4 due to evolving clinical signs. The CE-CT correctly predicted surgical findings in all cases. CONCLUSIONS: Hemodynamically stable patients with stab wounds to the back and/or flank can be successfully triaged based on CE-CT findings. Low-risk patients may be discharged immediately. High-risk patients may have a discharge decision implemented at 24 hours.

Re-engineering ventilatory support to decrease days and improve resource utilization.

OBJECTIVE: The objective of this study was to describe the development of a cost-effective ventilatory strategy using a portable microprocessor-controlled respiratory monitor (Bicore CP-100; Allied Healthcare Products, Riverside, CA.) SUMMARY BACKGROUND DATA: Until recently, clinicians have had to accept the uncertainties of clinical judgment, which unfortunately, often biased the patient to a prolonged ventilatory course to avoid extubation failures, necessitating reintubation. METHODS: Over a 4-year period, the authors attempted to re-engineer the process of ventilatory support based on measured work of breathing (WOB), including physiologic (WOBPhys), imposed (WOBImp) and total (WOBTot). RESULTS: The authors made 90 determinations of WOB in 31 patients. The coefficient of determination (i2) of WOBTot, with the breathing frequency was 0.35, with tidal volume was 0.10, and with the rapid shallow breathing index (f/V(tau)) was 0.23; therefore, the authors discarded them as reliable inferences. Of 27 patients ventilated for > 2 days with satisfactory blood gases, but with breathing frequency > 30 breaths/minute, 6 had WOBTot < 0.8 J/L and were extubated successfully. In 21 patients, WOBTot was elevated to 1.6 +/- 0.83 J/L, WOBImp was 1.1 +/- 0.64 J/L, approximately twice the WOBPhys (0.5 +/- 0.26 J/L), a normal value. Extubation was successful in 20 of those 21 patients. This approach was extended to the spontaneous breathing pre-extubation trial. In addition, the ventilator was adjusted so that the patient sustained a WOBTot of 0.6 to 1 J/L during the ventilatory support. This evolution was tracked for 18 months in a series of 838 trauma intensive care unit patients. Average duration of ventilation decreased from 8.2 to 4.2 days (49%; p < 0.01). This translated into approximately 2400 decreased ventilator days per year. CONCLUSION: Objective measurement to guide the adequacy of ventilatory support and interpret apparent clinical weaning failures decreased total ventilatory time by 50%, permitting extubation in nearly 20% of patients previously considered failures.

Preoperative intensive care unit consultations: accurate and effective.

OBJECTIVES: To determine if a structured preoperative ICU consultation would correctly assign patients to preoperative invasive monitoring, postoperative ICU care, or recovery room care, and to compare morbidity, mortality, and resource utilization among all groups. DESIGN: Prospective, observational study. SETTING: A university hospital. PATIENTS: A total of 475 patients who were referred preoperatively by surgeons for ICU consultation and were evaluated by ICU physicians. INTERVENTIONS: Patients assessed to have clinical evidence of cardiovascular compromise were admitted preoperatively to the ICU for invasive hemodynamic monitoring and optimization. Patients without such evidence, but who were to undergo major operations or had anticipated major fluid replacement were independently selected for invasive monitoring by anesthesiologists. Patients who developed physiologic instability or became unstable due to hemorrhage also underwent invasive monitoring. Nonmonitored patients who remained stable were given postoperative ICU care or went to the recovery room based on an assessment by the surgeon and anesthesiologist at the end of the operation. MEASUREMENTS AND MAIN RESULTS: Of 8,916 elective surgical cases, ICU physicians were consulted in 475 (5.3%) patients preoperatively. Sixty-seven patients were admitted preoperatively to the ICU for invasive hemodynamic monitoring and optimization; 60 patients had surgery (0.7% of elective cases, 12.6% of ICU consultations). Patients selected for ICU preoperative monitoring were older than non-monitored patients and had higher numbers of cardiovascular and total risk factors than any other group. They had higher Acute Physiology and Chronic Health Evaluation (APACHE II) scores, higher Therapeutic Intervention Scoring System (TISS) points, a higher number of complications, and longer ICU stays than non-monitored postoperative ICU patients. In addition, they had a higher number of complications than nonmonitored recovery room patients. APACHE II scores, TISS points, number of complications, and ICU days in the preoperative ICU admission group were not increased when compared with all other monitored patients. Neither hospital days nor total hospital charges were increased when compared with the other elective ICU patients. Patients selected for ICU preoperative monitoring who underwent surgery had an 11.7% mortality rate and accounted for four of five cardiovascular-related deaths. CONCLUSIONS: A small number of high-risk patients can be selected for preoperative monitoring on the basis of clinical assessment without increasing ICU stay or hospital bills. A structured preoperative consultation correctly identifies those patients who need monitoring and ICU care, but does not overutilize scarce and expensive ICU beds.

Further appraisal of APACHE II limitations and potential.

Hemodynamically unstable patients selected for invasive cardiovascular monitoring were divided into APACHE II subgroups for risk stratification to study interrelationships among monitoring, therapy, resulting cardiovascular function and outcome. When compared by regression analysis, there were no clinically relevant relationships between APACHE II scores and total intervention points (r2 = 0.02), days of invasive monitoring (r2 = 0.000001), initial cardiovascular function (r2 = 0.069) and final cardiovascular function (r2 = 0.05). Analysis of variance (ANOVA) was done between APACHE subgroups and total points (zero of 20 intragroup comparisons were different by the Scheffé test; p = 0.33), days of monitoring (zero of 20 were different; p = 0.61), initial cardiovascular function (three of 20 comparisons were different; p = 0.003) and final cardiovascular function (zero of 20 were different; p = 0.24). Opposite relationships in patients who lived and died were noted between total intervention points and APACHE II subgroups (p = 0.028, two-way ANOVA). There was an increasing number of total intervention points in patients who ultimately lived in ascending initial APACHE II subgroups. In contrast, there was a decreasing number of total intervention points in patients who ultimately died in the same APACHE II subgroups. APACHE II stratification failed to help understand the relationships among clinically important parameters. At the same time, while APACHE scores are claimed to be independent of therapy, the score seemed to be extremely sensitive to interventions, especially important in surgical populations. Should the APACHE II scores remain high in the face of continued maximal intervention, fatal outcome can be predicted. This pattern is remarkably similar across the entire initial APACHE spectrum. The predicated attributes of APACHE II scores, that is, risk stratification and independence from therapy, are neither necessary or desirable. Understanding patterns that are associated with survival or death may require alternative mathematic approaches, such as group and set theory manipulated by principles of Boolean algebra. New approaches may be more fruitful than further attempts to refine existing systems.

Evaluation of APACHE II for cost containment and quality assurance.

APACHE II (an acronym formed from acute physiology score and chronic health evaluation) has been proposed to limit intensive care unit (ICU) admissions ('cost containment') and to judge outcome ('quality assurance') of surgical patients. To judge its performance, a 6-month study of 372 surgical ICU patients was performed. When patients were divided by mean duration of stay, mortality rates rose from 1% (short stay) to 19% (long stay) (p less than 0.001) for patients with APACHE II scores less than 10, but decreased from 94% (short stay) to 60% (long stay) (p less than 0.01) for patients with APACHE II scores more than 24. Exclusion of patients by high or low APACHE scores would 'save' 6% of ICU days but risk increasing morbidity, hospital costs, and deaths. Grouped APACHE II scores did not correlate with total hospital charges (r = 0.05, p = 0.89) or ICU days used (r = 0.42, p = 0.17). Grouping by APACHE II score and duration of ICU stay showed neither symmetry nor uniformity of mortality rates. Surgical patients would not be well served by APACHE II for quality assurance or cost containment.

Risk and detection of pulmonary artery catheter-related infection in septic surgical patients.

Specimen cultures were evaluated in 49 catheterized patients who had a known focus of infection (primarily intra-abdominal peritonitis). Bacteria were recovered from 2% of flush solutions, 14% of transducer domes, 18% of diaphragms, and 24% of cardiac output fluids; however, these bacteria were not found in cultures of the pulmonary artery (PA) catheter segments. The rates of positive PA catheter-aspirate cultures were 30.6% on day 1, 20.4% on day 2, and 32.7% on day 3 (not statistically different). PA catheter-aspirate cultures had a sensitivity of 5.7% and a positive predictive value of 30% for catheter-related infection, and 15% sensitivity and 40% positive predictive value for peripheral bacteremia. While 95% (55 of 58) of the catheter-aspirate cultures were false-positives, only 0.5% (3 of 588) were true-positives. Peripheral blood cultures were positive in 10% of the patients, but the catheter segments were sterile or grew different organisms. Arterial line cultures had zero sensitivity and predictive value to detect catheter-related infection, and 15% sensitivity and 40% predictive value to detect peripheral bacteremia. Thus, PA catheter-aspirate cultures, routine peripheral blood cultures, and arterial cultures cannot be recommended to detect PA catheter-related infection. Catheter-related infection confirmed by catheter-segment cultures was 10.2% when the PA catheters were removed after 73 +/- 6.5 (SD) h. Bacteria from catheter-segment cultures corresponded to those from the primary infection site.

Titrating positive end-expiratory pressure therapy in patients with early, moderate arterial hypoxemia.

A prospective randomized study to compare two physiologic end-points for titrating positive end-expiratory pressure (PEEP) was performed in patients with early, moderate arterial hypoxemia after surgery or trauma. All patients initially received 5 cm H2O of PEEP. In group 1 patients, PEEP was increased only if PaO2 decreased below 65 torr on an inspired oxygen fraction (FIO2) of 0.45. PEEP was then added in 2- to 3-cm H2O increments until PaO2 again was above 65 torr. Group 2 patients were treated with incremental PEEP until the PaO2/FIO2 ratio was greater than 300 or physiologic shunt (Qsp/Qt) was less than 0.20. All therapy other than PEEP was similar in the two groups. There were no statistically significant differences in entry PaO2 (mean 85 +/- 11 [SD] and 87 +/- 11 torr in groups 1 and 2, respectively), and Qsp/Qt was 0.22 in each group. Five (28%) of 18 patients in group 1 and 19 (95%) of 20 patients in group 2 received more than 5 cm H2O of PEEP. Between groups 1 and 2 there were no statistically significant differences in days intubated (3.4 +/- 3 vs. 5.3 +/- 5, respectively), ICU days (5.3 +/- 3 vs. 6.6 +/- 5), hospitalization days (26 +/- 24 vs. 28 +/- 24), incidence of pulmonary barotrauma (0/18 vs. 1/20), ICU mortality (22% vs. 20%), or overall mortality (33% vs. 25%). The number of blood gas analyses and cardiac output measurements, and the total hospital charges were also similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Maintaining quality of care while reducing charges in the ICU. Ten ways.

We believed that the dilemma of controlling costs yet maintaining quality of care might be approached in 10 ways designed to improve efficiency of care: principles of management, elimination of standing orders, classification of patients, written guidelines, mandatory communication, no repetitive orders, single order for single test, removal of monitoring catheters, constant administrative attention, and feedback. We monitored quality of care using the therapeutic intervention scoring system (TISS), mortality, utilization of bed days in the ICU, and the total hospitalization of 50 patients treated in April 1983 and, 8 months after the interventions, 50 patients treated in February 1984. There were no differences in the patient population, severity, outcome, or days. The total lab bills were $10,000 in 1983 and $6300 in 1984 (p less than 0.01). The total number of tests decreased by 2803 (42%) from 6685 to 3882, or 56 per patient per admission. Calculated ICU laboratory charges per patient decreased $3226 (53%) from $6210 to $2894. In 1983, while patients spent 15% of their hospital days in the ICU, they accumulated 61% of their total laboratory charges. In 1984, ICU days were 19% and ICU laboratory charges were 46% of the total. If the decrease of $3226 per patient is extrapolated to a year's population, this would decrease charges by over $2,000,000 in one 12-bed surgical ICU.