| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
|
Interact CardioVasc Thorac Surg 2008;7:32-36. doi:10.1510/icvts.2007.164855 © 2008 European Association of Cardio-Thoracic Surgery
Do patients after off-pump coronary artery bypass grafting need the intensive care unit? A prospective audit of 85 patients
a Department of Cardiac Surgery, Hôtel-Dieu du CHUM, Université de Montréal, Montréal, Québec, Canada Received 10 August 2007; received in revised form 16 October 2007; accepted 23 October 2007
*Corresponding author. Professeur Adjoint de Clinique, Departement de Chirurgie Cardiaque, Hotel Dieu de Montreal, 3840 Rue St Urbain, Montreal, Canada H2W 1T8. Tel.: +1-514-890-8131; fax: +1-514-412-7231.
With limited resources, cardiac surgery is frequently cancelled due to lack of ICU beds. Immediate postoperative extubation (UFT) is performed in our hospital setting. The aim of the present study is to report patients undergoing off-pump aortocoronary bypass grafting (OPCABG) with immediate extubation and no ICU stay. Eighty-five patients undergoing OPCABG were included. UFT analgesia consisted of high thoracic epidural analgesia (n=65), or PCA morphine (n=20). Discharge criteria from PACU to cardiac ward were: alert, cooperative patient, respiratory rate <25/min, PaO2>80 mmHg and PaCO2<45 mmHg, temperature >36 °C, hemodynamic stability, no bleeding, no ischemia, and sufficient analgesia. More males (71/14) were included. Mean age was 63.4 years, NYHA class III, ejection fraction 59.4. Three grafts were performed in 119 min. Patients were extubated 12±2 min after closure. After 428 min in PACU, four patients did not meet ward criteria; three bradycardia requiring pacing, one elevated CK-MB. Two patients returned to the ICU, one for hypertension, and one for hypovolemia. Cardiac complications were: atrial fibrillation (29%), MI=2, bradycardia=3. During the same period, 304 OR-extubated patients spent 21±6 h in the ICU. The cost from leaving the OR until the patient reached the cardiac ward was 1265$ for ICU bypass patients vs. 6405$ for ICU patients, the difference representing 5140$ per patient. ICU bypass after OPCABG is safe. By avoiding ICU, this protocol reduces costs, improves resource utilization and may reduce OR cancellation due to ICU bed shortages.
Key Words: Cardiac anesthesia; Off-pump coronary artery bypass grafting; Resource utilization; Length of stay
Coronary artery bypass grafting (CABG) is the most frequently performed surgery in the US and Canada [1, 2]. Efficient use of hospital resources for CABG is a topic of increasing concern among clinicians, administrators and researchers. Dramatic changes in the cost of medical care and intensive care unit (ICU) bed availability have put substantial pressures on healthcare providers to focus on efficient resource utilization [3]. In the current setting, cardiac operations are frequently cancelled due to lack of ICU bed availability. Moreover, prolonged ICU stays are linked with greater use of resources; they increase the overall costs of cardiac surgery and may also limit the number of operations performed [4, 5]. Despite efforts to reduce the ICU time, cardiac surgery patients are routinely monitored in the ICU for a period of time ranging from one to several days [4, 6]. The traditional operative technique for coronary artery bypass grafting relies on the establishment of cardiopulmonary bypass (CPB) [1]. However, CPB is associated with a number of adverse outcomes that are primarily related to aortic manipulation, the ignition of systemic inflammation and microembolization [7]. Off-pump coronary artery bypass grafting (OPCABG) has been proposed to improve morbidity, resource use and costs. In an attempt to decrease the resource utilization, some anesthesiologists currently extubate patients after cardiac surgery in the operating room (Ultra-fast track anesthesia, UFT). These patients were routinely sent to the post-anesthesia care unit (PACU) for 2–4 h before being transferred to the ICU. Selected OPCABG patients successfully extubated in the OR, stable in the PACU, were directly sent to the cardiac surgery ward, bypassing the ICU. The aim of the present report is to audit the patients directly sent to the cardiac surgery ward, bypassing the ICU, in terms of safety and the impact on resource utilization and costs.
2.1. Patients The study was conducted from 1 August 2004 to 31 July 2006 at the Hotel-Dieu de Montreal Hospital. This is a 300-bed university affiliated hospital performing 400 cardiac surgeries per year. The ICU is a closed 14-bed medico-surgical ICU under the direction of certified intensivists and the ten-bed closed PACU was run by anesthesiologists. Per hospital policy, no intermediate care unit was available. The 35-bed cardiology/cardiac surgery ward included eight ECG telemetry equipped beds. All patients with symptomatic coronary artery disease were prospectively enrolled in our pilot study and scheduled for conventional midline sternotomy and OPCABG. All three cardiac surgeons in our institution participated in this study, and 6 out of 13 anesthesiologists participated in the ultra-fast track cardiac surgery program. The other seven anesthesiologists sent the patients routinely intubated into the ICU. Patients were considered eligible for UFT and ICU bypass if they had isolated coronary artery disease and an ejection fraction (LVEF) >30%. Exclusion criteria included congestive heart failure, preoperative hemodynamic instability or intraaortic balloon pump, emergency surgery, recent (<1 week) myocardial infarction (MI), associated valvular disease, pulmonary hypertension (PAsystolic >50 mmHg), previous cardiac surgery or patient refusal. Obesity, diabetes, age or chronic renal failure not requiring dialysis was not considered exclusion to enroll in the program. All routine cardiac medications were continued on the morning of surgery. Antiplatelet drugs (except aspirin) were stopped more than five days before surgery. 2.2. Peri-operative management Anesthetic management (Table 1) included an epidural when feasible. A 20G catheter was placed through an 18G needle (B Braun, Bethlehem, PA, USA) and secured in place by a clamp (Lockit, Portex Medical, Pointe Claire, Québec, Canada). All surgeries were done by complete midline sternotomy and specific details are shown in Table 1.
2.3. Postoperative care Hemodynamically stable patients who met several criteria (Table 1) were extubated in the operating room and transferred to the PACU. Upon PACU arrival, routine care was applied, including laboratory analysis, chest X-rays and 12-lead ECG. Active external warming was provided. Analgesia was provided by TEA (bupivacaine 1 mg/ml 6–12 ml/h) or intravenous morphine loading followed by patient controlled analgesia (PCA, 1 mg, 6 min lookout). The ICU bypass program was led by PACU nurses with extensive (>20 years) ICU experience. Regular PACU nurses were trained during this program and all PACU nurses were able to care for these patients. Patient installation and initial work-up was done by 1–2 nurses, the patients were cared on a one nurse to one patient basis for the first 2 h and could then be monitored on a one nurse to two patients basis. After 6 h in the PACU, the drainage tubes and the arterial line were removed, a control chest X-ray was performed and the patients were discharged to a regular cardiac surgery ward with an ECG telemetry (Table 1). 2.4. Data collection and statistical analysis Preoperative, intra-operative and PACU data collection was performed by the cardiac surgeons, perfusionists, cardiac anesthesia team and the PACU nurses. All data were entered in the PeriCARG research database. During the same period the ICU collected data using their clinical information system (SEMI v6.0.9, Semi Data Corporation, Montreal, Canada). Both databases were merged using the hospital file number and the surgery date and analyzed using SAS statistical package (JMP version 5.1.0.2, SAS Institute, Cary, NJ). Study population descriptors are presented as mean and standard deviation and range when appropriate. Costs were calculated from OR exit to cardiac surgery ward admission. ICU costs were based on ventilated and non-ventilated costs previously published [8]. PACU costs were derived from nursing costs [9] available adding a 50% for overhead costs. As the Canadian dollar is almost equal to the US dollar, both were used interchangeably.
From 1 August 2004 to 31 July 2006, 853 elective patients underwent cardiac surgery at the Hotel Dieu de Montreal. Nineteen patients received an on-pump bypass, 211 valves or combined surgeries and elective OPCABG was performed in 623 patients. Of these, 234 were transferred intubated into the ICU, 389 extubated in the OR and 85 bypassed the ICU. These latter patients constituted the study cohort. Their mean age was 63.4±9.8 years (range: 44–81). There were more males (71/14). Median preoperative NYHA class was III (Table 2). Patient characteristics of the ICU bypass cohort were similar to our average patients.
All patients were successfully operated for OPCABG, no conversion to on-pump CABG occurred. Total operative time was 119±29 min (45–215), for 3±1 grafts (1–6). Cumulative ischemic time was 19±7 min (7–43), the internal mammary artery was used in 91% of the patients. There was no hemodynamic instability, no use of intra-aortic balloon pump counterpulsation (IABP). All patients were successfully extubated in the operating room within 15 min following skin closure. Postoperative analgesia consisted of TEA (n=65) or PCA (n=20). No complication occurred related to TEA, such as hematoma or neurological sequels were observed. Mean PCU stay was 428±57 min. Four patients (4.7%) failed to be transferred to the cardiac ward and were sent to the ICU. Three patients suffered from bradycardia requiring external atrial pacing, one patient had elevated CK-MB fractions. After successful discharge to the cardiac ward, two patients were sent to the ICU: one for hypertension and one for low output syndrome the day after surgery due to hypovolemia. Postoperative atrial fibrillation occurred in 25 patients (29%), myocardial infarction in two patients, bradycardia in three patients. Only five patients required blood transfusion (5.9%), 1 unit of blood each. 3.1. Cost-comparison comparisons During the same period, a comparable group of 304 electives patients underwent OPCABG in our institution, receiving UFT anesthesia. These patients were also extubated in the operating room and sent to the ICU for an average of 21±6 h. Costs for extubated patients cared in the ICU is evaluated to 6405 US$. For ICU-bypass patients, cost for 7 h PACU was estimated to 1265 US$. Accordingly, the difference is 5140 US$ per patient. The 79 patients effectively bypassing the ICU represent a saving of 69 ICU days or 407,000 US$ ICU resources.
The present audit shows that a specific pathway applied from the patient's entry into the operating room to discharge to the cardiac ward results in low-risk patients bypassing the ICU after OPCABG. Careful peri-operative technique leads to a postoperative course similar to major thoracic, vascular or abdominal surgery. The present audit includes six patients who either failed the PACU-to-ward initial discharge criteria or required unplanned ICU admission after being transferred to the cardiac ward. Five out of these six patients required only surveillance (three external pacing, one surveillance of elevated myocardial enzymes and one for hypovolemia) equivalent to priority-2 ICU admission criteria. One patient required nitroprusside for severe hypertension, a therapy that could not safely be administered in a regular ward. It must be stressed that our hospital has no intermediate care unit and these patients could have been managed in such a unit. Historically, patients undergoing cardiac surgery required postoperative intensive care support techniques to assist the respiratory function jeopardized by cardiopulmonary bypass and fluid overload, to assist respiratory mechanics depressed by large doses of opioids and neuromuscular blockers, and to counterattack pathophysiological disturbances, due to such as hypothermia, ischemia/reperfusion injury. In the last 15 years, fast track cardiac anesthesia has gained popularity, allowing extubation within 8 h [10]. Recently several authors, including our group, proposed ultra-fast track with immediate OR extubation. This technique is feasible and presents no increased risk of complication. Fast track and UFT patients require less postoperative resources compared to classical cardiac surgery patients. In order to benefit from this decreased resource utilization, the postoperative care structure has to be adapted. Recent studies of UFT anesthesia [11] underline the need to establish necessary infrastructures to translate the benefit of immediate extubation to shorter stay. Two recent cohorts of immediate operating room extubation [12, 13] did not show resource utilization gains since patients were sent to a regular ICU. The originality of the present cohort is not in trying to further reduce the ICU stay but to change the pathway of patients undergoing cardiac surgery: from an ICU pathway change to a pathway similar to major non-cardiac surgery (Figs. 1, 2).
The optimal setting for postoperative cardiac care is a matter of debate and several models have been proposed. Specific intermediate or down-step care units could absorb a part of the work usually done in a regular ICU. This unit could focus on hemodynamic monitoring, the need for temporary epicardial pacing and routine wound and chest drains care. Continuous ScvO2 or cardiac output monitoring could be possible in these units using arterial pulse contour analysis. The optimal setting for postoperative care has not been established yet (Fig. 2). A model involving different patient acuity with adapted staffing in the same physical unit has been proposed and seems advantageous in terms of continuity of care and resource utilization [14, 15]. An UFT patient successfully extubated in the OR will not require a ‘full capacity’ ICU, may be safely managed in a down-step unit or directly to the ward after a short PACU stay. To gain the full benefits in terms of resources utilization, these patients should be managed in a setting offering the appropriate level of care. The present cohort represents a selected subset of patients bearing a low risk of peri-operative complications. These selected patients were enrolled in a clinical pathway focusing on expedite and meticulous care which might not be applicable to all patients. The short surgery time certainly facilitates UFT. Direct cost estimates were not available in our institution but are based on average hourly costs for PACU vs. ICU costs already published from different sources.
Immediate operating room extubation is feasible and safe in patients undergoing OPCABG. Instead of spending an ICU stay as short as possible, a part of these patients can safely bypass the ICU during their postoperative care. Surgeons and anesthetists have to think outside the box, outside the traditional operating room, ICU, down-step unit, ward scheme to implement innovative peri-operative concepts and adapting the postoperative settings to improve a patient's flow through the healthcare system.
The authors are indebted to all the operating room, PACU and cardiac surgery ward personnel involved in this clinical pathway for their implication and commitment. The authors wish to thank the more senior and ICU experienced PACU and ward nurses for their commitment and teaching of their more novice partners in the care of immediate postoperative patients.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
Top
Abstract
1. Introduction
