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Biomedical subjects

J M Civetta

Publications and source records attributed to J M Civetta.

At least 19 recordsLinked to original sources

Beyond requirements: residency management through the Internet.

HYPOTHESIS: An Internet application could collect information to satisfy documentation required by the Residency Review Committee. Beyond replacing a difficult and inefficient paper system, it would collect, process, and distribute information to administration, faculty, and residents. DESIGN: Descriptive study. SETTING: An integrated residency of 18 services at a university teaching hospital with 4 affiliated institutions. PARTICIPANTS: Residency administrators, faculty, and residents. INTERVENTIONS: The application included a procedure recorder, resident evaluation of faculty and rotations, goals and objectives (stratified by service and resident level), and matching faculty evaluation of residents with these goals as competencies. Policies, schedules, research opportunities, clinical site information, and curriculum support were created. MAIN OUTCOME MEASURES: Degree of compliance with Residency Review Committee standards, number of deficiencies corrected, and quantity and quality of information available to administration, faculty, and residents. RESULTS: The Internet system increased resident compliance for faculty and rotation evaluations from 20% and 34%, respectively, to 100%, which was maintained for 22 months. These evaluations can be displayed individually, in summary grids, and as postgraduate year-specific averages. Faculty evaluations of residents can be reviewed throughout the system. The defined category report for procedures, which had deficiencies in the preceding 6 years, had none for the last 2 years. The Internet application provides Accreditation Council for Graduate Medical Education-validated operative logs to regulatory agencies. CONCLUSIONS: A Web-based system can satisfy requirements and provide processed data that are of better quality and more complete than our paper system. We are now able to use scarce time and personnel to nurture developing surgical residents instead of shuffling paper.

Connecticut↗

Measuring service-specific performance and educational value within a general surgery residency: the power of a prospective, anonymous, Web-based rotation evaluation system in the optimization of resident satisfaction.

BACKGROUND: We used a Web-based evaluation system to institute specific changes to various clinical teaching services in our integrated residency in an effort to optimize the overall quality of the educational experience and measured the resident satisfaction in these rotations. METHODS: Residents rated 8 categories of experience on a scale of 1 to 5 (maximum summation score, 40 points). Data were analyzed by t-test for equality of means. A probability value of less than.05 was considered significant. RESULTS: Compliance with completion of the evaluations was 100%. The Chronbach's alpha reliability coefficient of the tool was 0.826. Tukey's estimate of power to achieve additivity was 1.5. Six under-performing services were re-engineered with prominent effects on 7 postgraduate year (PGY) rotations. On 2 general surgery services at 1 hospital, the workload was redistributed, and a dedicated team teaching time was instituted (PGY-3 [a]: before, 22 points/after, 31 points; P =.003; PGY-3 [b]: before, 25 points/after, 31 points; P =.004; PGY-1: before, 24 points/after, 29 points; P =.07). A general surgery service at another hospital redistributed coverage of the attending surgeons to create a nonteaching service (PGY-1: before, 22 points/-after, 27 points; P =.01). The transplantation service (PGY-3) was examined, and the role of the point was redefined (before, 24 points/after, 31 points; P =.01). One vascular service (PGY-2) redistributed cases and workload (before, 27 points/after, 22 points; P =.07). The vascular PGY-2 position was eliminated and replaced by a mid-level practitioner. The cardiothoracic service (PGY-1) rotation was converted into a preceptorship (before, 23 points/after, 30 points; P =.015). CONCLUSIONS: A web-based clinical rotation evaluation provides a means for the assessment of the impact of programmatic changes while preserving resident anonymity and maintaining accountability.

General Surgery↗

Critical palliative care: intensive care redefined.

In the area of end-of-life bioethical issues, patients, families, and health care providers do not understand basic principles, often leading to anguish, guilt, and anger. Providers lack communication skills, concepts, and practical bedside information. Linking societal values of the sanctity of life and quality of life with medical goals of preservation of life and alleviation of suffering respectively provides an essential structure. Medical care focuses on cure when possible but when the patient is dying, the focus switches to caring for patients and their families. Clinicians need to learn how to balance the benefits and burdens of medications and treatments, control symptoms, and orchestrate withdrawal of treatment. Finally, all need to learn more about the dying process to benefit society, their own families, and themselves.

Advance Directives↗

Cost and morbidity associated with antibiotic prophylaxis in the ICU.

BACKGROUND: Although the high cost and inappropriate use of antibiotics have been documented before, we are not aware of any data on nonsurgical site infectious morbidity associated with prolonged courses of prophylactic antibiotics (PA). STUDY DESIGN: Data regarding antibiotic orders were collected using a custom designed microbiology database in the Surgical Intensive Care Unit of a teaching hospital from October 1, 1995 through April 30, 1997. The database was retrospectively reviewed. The cost of PA in excess of 1 day was calculated. Frequency of bacteremia and line infections were compared in patients receiving 1 day or less of PA versus more than 4 days of PA. RESULTS: Sixty-one percent of PA orders were continued for more than 1 day. Cost of PA beyond 1 day totaled $44,893. Bacteremia and line infection were more frequent in the patients receiving more than 4 days of PA. CONCLUSIONS: There was poor compliance with the protocol of stopping PA at 24 hours. The cost of noncompliance was $44,893. There were more bacteremias and line infections in patients with duration of PA of more than 4 days.

Anti-Bacterial Agents↗

Strategies to prevent organ failure.

The gastrointestinal tract and the generalized inflammatory response initiated by severe injury or infection have been implicated in the pathophysiology of multiple-organ system failure. Once multiple-organ system failure has occurred, treatment focuses on supporting end-organ function. Recent studies have shown, however, that it may be possible to reduce the incidence and prevalence of multiple-organ system failure by controlling the reperfusion injury cascade, normalizing gastrointestinal blood flow and preserving the integrity of the gastrointestinal immune barrier.

Journal Article↗

Empiric therapy of sepsis in the surgical intensive care unit with broad-spectrum antibiotics for 72 hours does not lead to the emergence of resistant bacteria.

BACKGROUND: It is our practice to treat suspected sepsis with imipenem/cilastatin and gentamicin (IMP/GENT) for 72 hours while awaiting culture results. We wanted to determine if this practice engenders antimicrobial resistance. METHODS: Review of prospectively collected data regarding use of IMP/GENT and microbial sensitivity to imipenem/cilastatin during the first and last 7 months of a 19-month study period (October 1, 1995, to April 30, 1997). RESULTS: The susceptibility of appropriate organisms to imipenem/cilastatin was 76% in the early period and 80% in the late period (p = 0.42). Pseudomonas aeruginosa was more susceptible in the late period (88 vs. 62%; p = 0.007). Resistance to gentamicin (30% early vs. 21% late; p = 0.02) and representative cephalosporins (cefoxitin, 52% early vs. 61% late; p = 0.35; ceftazidime, 26% early vs. 23% late; p = 0.76) did not develop during the study period. The incidence of fungemia was the same in both periods (4 of 467 admissions vs. 3 of 599 admissions; p = 0.48). CONCLUSION: This protocol did not lead to the emergence of resistant bacteria.

Adolescent↗

Failure of splanchnic resuscitation in the acutely injured trauma patient correlates with multiple organ system failure and length of stay in the ICU.

INTRODUCTION: The purpose of our study was to evaluate the relationship between the state of splanchnic perfusion and morbidity and mortality in the hemodynamically unstable trauma patient acutely resuscitated in the ICU. METHODS: Gastric intramucosal pH (pHi) was monitored in a blinded fashion in 19 consecutive critically ill trauma patients with evidence of systemic hypoperfusion (arterial pH [pHa] <7.35, base excess >2.3 mmol/L, lactic acid >2.3 mEq/L) who received right heart catheters to guide resuscitation and subsequent hemodynamic monitoring. DESIGN: Prospective randomized consecutive series with retrospective analysis of data. SETTING: University hospital, surgical ICU. RESULTS: The mean values of APACHE II (acute physiology and chronic health evaluation) Injury Severity Score, pHa, arterial base excess, cardiac index, oxygen delivery index, and oxygen consumption index by 24 h were similar (Student's t test, p>0.1) between survivors and nonsurvivors and between those who developed at most a single (SOF) vs multiple organ system failure (MOSF). Supranormal oxygen delivery and utilization parameters were evenly distributed among survivors and nonsurvivors and patients with SOF and MOSF (chi2, p>0.5). Ten patients had a pHi <7.32 and nine patients had a pHi > or = 7.32 by 24 h. Fifty percent of patients with a pHi <7.32 died, compared with 11% of patients with a pH > or = 7.32 (chi2, p=0.07). Sixty percent of patients with a pHi <7.32 developed MOSF compared with 11% of patients with a pHi > or = 7.32 (chi2, p=0.03). The one patient who developed MOSF and died in the pHi > or = 7.32 cohort suffered from massive head trauma and had all futile medical interventions halted. No other patients who achieved a pH > or = 7.32 by hour 24 developed MOSF. Survivors with a pHi <7.32 at hour 24 had an increased ICU stay (pHi <7.32=46+/-15 days, pHi > or = 7.32=13+/-9 days; p<0.01). A pHi <7.32 carried a relative risk of 4.5 for death and 5.4 for the occurrence of MOSF. CONCLUSION: Attainment of a pHi > or = 7.32 at hour 24 carried a significantly reduced likelihood of MOSF. Being an inference of the state of regional perfusion, in a high-risk microvascular bed, gastric intraluminal tonometry should identify perfusion states of compensated or uncompensated shock during hemodynamic resuscitation of the critically ill injury patient. A low pHi appears to be a marker of postresuscitative morbidity and subsequent increased length of stay.

Critical Care↗

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.

Adult↗

Do pulmonary artery catheters alter outcome in trauma patients?

OBJECTIVE: To review the literature addressing the use of the pulmonary artery catheter (PAC) in victims of blunt and penetrating trauma and examine the available evidence that supports or refutes the claim that PAC use alters outcome in this patient population. Furthermore, to determine what additional research should be done in this area. DATA SOURCE: All pertinent English language articles dealing with pulmonary artery catheterization in trauma patients were retrieved from 1979 through 1996. STUDY SELECTION: Clinical studies were considered if PACs were used to establish a cardiopulmonary diagnosis, optimize or achieve endpoints of oxygen transport and utilization indices, or guide and/or determine response to therapy. Emphasis was placed on prospective, randomized, controlled trials. However, descriptive case series and retrospectively-analyzed, uncontrolled reviews comprise the majority of available literature. DATA EXTRACTION: From these selective studies, information was obtained regarding patient demographics, therapeutic endpoints, and achieved outcome. DATA SYNTHESIS: Insufficient evidence exists to support a true survival benefit. However, recommendations for indications can be proposed where a reduction in morbidity or improvement in functional outcome is suggested. CONCLUSION: Hemodynamic data obtained from the PAC appear to be beneficial for the following indications: a) to ascertain the status of underlying cardiovascular performance and/or the need for improvement; b) to direct therapy when noninvasive monitoring may be inadequate, misleading, or the endpoints of resuscitation difficult to define; c) to assess response to resuscitation; d) to potentially decrease secondary injury when severe closed-head or acute spinal cord injuries are components of multisystem trauma; e) to augment clinical decision-making when major trauma is complicated by severe adult respiratory distress syndrome, progressive oliguria/anuria, myocardial ischemia, congestive heart failure, or major thermal injury; and f) to establish futility of care.

Adult↗

Cost effectiveness in the intensive care unit.

Effective policies to reduce true costs will require integrated information systems and demand behavioral changes from providers. A congenial environment must be created among medical educators, providers, vendors, and consumers if cost reduction is to be accomplished without compromising quality or access to critical care services. Physicians should do everything they believe may be of benefit for their patients, but we have an obligation to educate the public about the limitations of our art and the fact that "doing everything" is not always best for the patient or the grieving family. A significant method of controlling ICU costs is closely monitoring which patients are admitted and when they are discharged. Laboratory tests represent a source of cost reduction, and physicians must learn to order specific tests and not simply a battery of tests which includes the actual test desired. Limits should be placed on the tests that are ordered in terms of number and frequency. Improved efficiency of the utilization of resources should improve the care of our patients. The largest budget item of any or most critical care units is nursing; it is paramount that this essential and invaluable resource be utilized in a cost-effective manner. Diminishing unnecessary activity will both decrease complications and have salutary effects. Having more time to be with patients and their families will decrease our sense of failure and fulfill the important goal of caring. Physicians and nurses can return to thinking, assessing, and decision making instead of frenetically ordering, reacting, and intervening, which, we believe, accurately describes informational overload created by undue emphasis on high technology. In this way, we can respond to Fuch's exhortation that "physicians consider the possibility of contributing more by doing less." In responding, however, we must never forget that the societal, not merely the economic impact of medical care, is our principal consideration. We must first contribute more by achieving a greater understanding of the medical care process. Only then can we know how to do less at the bedside. We can and must distinguish between costly and high-quality care--they are not necessarily synonymous.

Cost Control↗

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.

Adult↗

Breathing measurement reduces false-negative classification of tachypneic preextubation trial failures.

OBJECTIVES: There is increased awareness of imposed work of breathing contributing to apparent ventilatory dependency. This study evaluates the impact of tachypnea as an indicator of ventilatory failure during a room air-5 cm H2O continuous positive airway pressure, spontaneous breathing, preextubation trial when associated with increased imposed work of breathing. DESIGN: Prospective, descriptive, 1-yr data collection. SETTING: University hospital trauma intensive care unit (ICU). PATIENTS: Mechanically ventilated trauma ICU patients surviving to discharge. INTERVENTION: Patients were weaned to minimal mechanical ventilator support and underwent a 20-min room air-continuous positive airway pressure preextubation trial (FIO2 = 0.21, continuous positive airway pressure = 5 cm H2O [0.5 kPa]). When passed (PaO2 >/= 55 torr [>/= 7.3 kPa], PaCO2 </= 45 torr [</= 6.0 kPa] with prior eucapnea, arterial pH >/= 7.35, respiratory rate </= 30 breaths/min), extubation followed. If patients failed due to hypoxia, ventilatory support resumed. If tachypnea was the reason for failure, work of breathing was measured. If patient work of breathing was </= 1.1 joule/L, extubation proceeded despite tachypnea. If patient work of breathing was > 1.1 joule/L, imposed work of breathing was measured, and if residual "physiologic" work of breathing (patient work of breathing minus imposed work of breathing) was </= 0.8 joule/L, patients were extubated. MEASUREMENTS AND MAIN RESULTS: Of 589 extubations, 105 (18%) were classified as false negatives based on a preextubation rate of > 30 breaths/min. Of these, 97 were successfully extubated despite tachypnea ranging from 32 to 56 breaths/min, when combined with either a patient work of breathing </= 1.1 joule/L or physiologic work of breathing </= 0.8 joule/L. The rate of extubation failure within 72 hours was 7.8% (8/105) in the tachypneaic group, compared with 7.9% (38/484) for those patients with a respiratory rate of </= 30 breaths/min. Some of the stimulus for the tachypnea was possibly due to increased imposed work of breathing, as the increased respiratory rate usually abated within 18 hrs after extubation. The reliance on a respiratory rate of </= 30 breaths/min as an absolute preextubation criterion would have resulted in a sensitivity of 82%, a specificity of 17%, a positive predictive value of 92%, a negative predictive value of 8%, and an overall accuracy of 77%. The average duration of mechanical ventilation during the study period decreased by 2 days, from 8.6 to 6.3 days (p=.03). CONCLUSIONS: Tachypnea as a marker of respiratory distress is sensitive, but is not sufficiently specific to be used as a criterion in preextubation trials. Reliance on tachypnea as a preextubation trial failure criterion is likely to prolong intubation and ventilatory support for a large number of patients. Patient risks, determined by the extubation failures and reintubation rate, are the same.

Adolescent↗

Decreasing catheter-related infection and hospital costs by continuous quality improvement.

OBJECTIVES: a) To reduce the rate of catheter-related infection, using improved skin preparation and catheters impregnated with silver sulfadiazine and chlorhexidine; b) to decrease the number of unnecessary guidewire exchanges of existing catheters by substituting suspected catheter-related sepsis for fever alone as an indication to change an indwelling catheter; and c) to decrease the hospital costs associated with guidewire exchanges and new catheter insertions. DESIGN: Sequential, prospective, descriptive studies using a continuous quality management approach. SETTING: A 20-bed trauma intensive care unit at a university teaching hospital. PATIENTS: Patients (n = 147) admitted from July 1 to December 31, 1992 (phase 1); 34 patients admitted in June and September 1993 (phase 2); and 156 patients admitted between January 1 and June 30, 1994 (phase 3). INTERVENTIONS: Phase 1: Proportions of catheter-related infections and catheter-related bacteremia were compared with our prior reported results. Indications for guidewire exchange were analyzed, and the rate of catheter-related infection for each indication was derived. Phase 2: The rate of catheter-related infection was determined for a trial group of triple-lumen catheters impregnated with silver sulfadiazine and chlorhexidine. Phase 3: Four components were altered. Impregnated triple-lumen catheters were used instead of unprotected catheters. Chlorhexidine skin cleanser was substituted for povidone-iodine solution during initial aseptic preparation during catheter insertion and subsequent guidewire exchange. Suspected catheter-related sepsis was substituted for fever as an indication for guidewire exchange. The "safe" period (the time before considering changing a catheter because catheter-related sepsis was suspected) was extended from 2 to 4 days. MEASUREMENTS AND MAIN RESULTS: The overall rate of catheter-related infection in phase 1 was 15% (15% for triple-lumen catheters and 16% for introducers). Catheters changed for site inflammation had a 46% rate of catheter-related infection, significantly higher than for all other indications, including fever (p < .03). The rate of catheter-related infection was significantly (p = .0002) higher for catheters in place for > 10 days compared with lesser durations. Fever was the indication for 42% of all guidewire exchanges. In phase 2, the catheter-related infection rate was 2% (one positive of 48 catheters), significantly (p = .0231) lower than the phase 1 rate. In phase 3, the overall rate of catheter-related infection was 8.6%, significantly (p = .0067) lower than the 15% rate in phase 1. The proportion of protected triple-lumen catheter catheter-related infections decreased significantly (p = .0024) from 15% to 6%. The rate of catheter-related infection for introducers was the same in both phases (p = .33). The days of catheterization for all catheters increased from 4.5 +/- 2.6 to 5.4 +/- 3.6 (p < .0001). The days for triple-lumen catheters increased from 4.7 +/- 2.7 to 7.0 +/- 3.9 (p < .0001). For introducers, there was no difference in the days of catheterization. The proportion of catheters changed for suspected catheter-related sepsis decreased significantly (p < .0001) to 23% from the 42% changed for fever in phase 1. The proportion of catheter-related infections for catheters changed for fever was 18% in phase 1. The proportion of catheter-related infections for catheters changed for suspected catheter-related sepsis was 13% in phase 3 (p = .43). The total number of catheters used per patient in phase 3 was 1.9 +/- 1.4, significantly lower than the 2.6 +/- 2.7 catheters used in phase 1 (p = .0018). The number of triple-lumen catheters decreased from 1.8 +/- 1.2 to 1.0 +/- 1.2 in phase 3 (p = .0001). CONCLUSIONS: Catheters impregnated with silver sulfadiazine and chlorhexidine had a smaller proportion of catheter-related infection compared with unprotected catheters. Fever alone as an indication for guidewire exchange resu

Anti-Infective Agents↗

Elevated imposed work of breathing masquerading as ventilator weaning intolerance.

OBJECTIVE: To test the hypothesis that, if apparent ventilatory insufficiency observed during a weaning or preextubation trial is due to a significant contribution of imposed work of the endotracheal tube and breathing apparatus (WOBImp), and the patient's actual physiologic work of breathing (WOBPhys) is not excessive, it should be possible to extubate these patients safely. DESIGN: Prospective descriptive study. SETTING: University hospital trauma intensive care unit. PATIENTS: A total of 28 (17% of all ventilated patients) adults intubated for 48 h or longer, who developed tachypnea (40 +/- 9 breaths/min) but whose blood gas exchange met predefined extubation criteria, were evaluated over a 3-month period. INTERVENTIONS: Using a microprocessor-based monitor (Bicore Monitoring Systems Inc, Irvine, Calif) total patient work of breathing (WOBTOT) was determined by integrating the change in intraesophageal pressure with tidal volume measured with a miniature pneumotachograph positioned at the airway opening. If the patient's WOBTOT was equal to or greater than 0.8 J/L, WOBImp was determined by integrating the changes in carinal pressures with tidal volume. If neither the patient's WOBTOT or WOBPhys was excessively greater than that of spontaneous breathing at rest (ie, < 0.8 J/L: normal range, 0.5 to 0.6 J/L), the patient was extubated. MEASUREMENTS AND RESULTS: Breathing frequency, peak inspiratory flow rate (PIFR), auto-Peep (PEEPa), dynamic compliance (CDXN) WOBTOT, WOBImp, resistance to expiratory airway flow (RAWE) were measured, and WOBPhys calculated (WOBTOT) minus WOBImp). The means and SDs were calculated, and data were analyzed by unpaired t test and linear regression. Six patients (5%) were found to have WOBTOT of < 0.8 J/L and were successfully extubated without determination of WOBImp. Twenty-one patients were found to have an elevated WOBTOT (1.6 +/- 0.83 J/L), and had WOBImp measured. In these 21 patients, WOBImp (1.1 +/- 0.64 J/L) was twice WOBPhys (0.5 +/- 0.26 J/L). Extubation was successful in 20 of 21 patients in which WOBPhys was determined not to be excessive (ie, < 0.8 J/L). The last patient had an elevated WOBPhys (1.4 J/L) and was not extubated until his disease improved later. Overall, reintubation rate was 4%. CONCLUSIONS: Increased WOBTOT may be misinterpreted as a patient failure (ie, tachypnea) and weaning halted or extubation not done, prolonging intubation. The ability to measure the contribution of WOBImp to WOBTOT can identify those patients who may be safely extubated when WOBphys (WOBTOT minus WOBImp) is acceptable and the apparent ventilatory insuffiency is related to significant WOBImp.

Adult↗