Extubation In Group Research Articles

Postoperative pulmonary function in coronary artery bypass graft surgery patients undergoing early tracheal extubation: A comparison between short-term mechanical ventilation and early extubation

Objective: To evaluate the effect of a short period of mechanical ventilation (3 hours) versus immediate extubation (within 1 hour of surgery) on pulmonary function, gas exchange, and pulmonary complications after coronary artery bypass graft (CABG) surgery. Design: Prospective randomized study. Setting: University teaching hospital. Participants: Thirty-five patients undergoing CABG surgery. Interventions: Patients were randomized into 2 groups. Patients in group I were extubated as soon as possible after surgery. Patients in group II were ventilated for a minimum of 3 hours after surgery. Patients in both groups were extubated only after achieving predetermined extubation criteria. Patients who did not meet the criteria for extubation within the predetermined set time limit (90 minutes in group I and 6 hours in group II) were withdrawn from the study. Pulmonary function tests (vital capacity, forced expiratory volume in 1 second, total lung capacity, functional residual capacity), arterial blood gases, and chest radiographs were done preoperatively and postoperatively. Pulmonary complications were recorded. Measurements and Main Results: Demographic data were similar between groups. The mean time to extubation in group I was 45.7 ± 27.6 minutes and in group II was 201.4 ± 21 minutes (p < 0.01). Two patients in group I and 1 patient in group II did not meet the extubation criteria within the predetermined set time limit and were excluded from the study. In both groups, there was a significant decline in pulmonary function but no differences between groups at 24 or 72 hours after surgery. There were no differences between groups in blood gases, atelectasis scores, or pulmonary complications. Conclusion: The data suggest that extending mechanical ventilation after CABG surgery does not affect pulmonary function. Provided that routine extubation criteria are met, patients can be safely extubated early (within 1 hour) after major cardiac surgery without concerns of further pulmonary derangement. Copyright 2002, Elsevier Science (USA). All rights reserved.

Alkalinization of Intracuff Lidocaine Improves Endotracheal Tube-Induced Emergence Phenomena

We sought to evaluate the effect of filling an endotracheal tube cuff with 40 mg lidocaine alone (Group L) or alkalinized lidocaine (Group LB) in comparison to an Air Control group (Group C) on adverse emergence phenomena in a randomized controlled study (n = 25 in each group). The incidence of sore throat was decreased for Group LB in comparison to Group L during the 24 postextubation hours. The difference between Group L and Group C remained significant in the two postextubation hours only. Plasma lidocaine levels increased when lidocaine was alkalinized (Cmax were 62.5 ± 34.0 ng/mL and 3.2 ± 1.0 ng/mL for Groups LB and L, respectively). Cough and restlessness before tracheal extubation were decreased in Group LB compared with Group L and in Group L compared with Group C. Nausea, postoperative vomiting, dysphonia, and hoarseness were increased after extubation in Group C compared with the liquid groups, and a better tolerance was recorded with Group LB compared with Group L. The increase of arterial blood pressure and cardiac frequencies during the extubation period was less in the liquid groups than in the control group and less in Group LB compared with Group L. We concluded that use of intracuff alkalinized lidocaine is an effective adjunct to endotracheal intubation.

Lidocaine Instilled into the Endotracheal Tube Suppresses the Cough Reflex during Emergence and Extubation

Background: Lidocaine sprayed down the endotracheal tube (ETT) before extubation and during ETT removal was reported to prevent increases in blood pressure and heart rate during and after extubation. We hypothesized that lidocaine administered via this route would suppress the cough reflex associated with tracheal extubation. Methods: Eighty-five patients requiring intubation in the supine position were studied. All patients received a standardized anesthetic protocol. At the end of surgery, the patients were randomly divided into three groups and given no drug (group I-control), given I mg/kg 2% lidocaine sprayed down the ETT 5 minutes prior to extubation (group 2), or given intravenous lidocaine (IVL) I mg/kg 3 minutes prior to extubation (group 3). Extubation was performed when the patients met the criteria of extubation. Number of coughs was recorded from 5 minutes before until 5 minutes after extubation. Each value was compared among the three groups. Results: Seventy-five patients completed this study (n = 25 for each group). The incidence of patients experiencing coughing was decreased in group 2 (P = 0.03), compared with group 3 or the control. Number of coughs per patient was significantly less in group 2 (P = 0.00). IVL did not significantly diminish the incidence or the amount of coughing compared with the control. Conclusions: Lidocaine sprayed down the ETT suppresses cough reflex and is more effective than IVL in blunting the cough reflex. This study indicates that lidocaine sprayed down the ETT has a topical anesthetic effect suppressing the cough reflex.

Predictors and outcomes associated with early extubation in older adults undergoing coronary artery bypass surgery

Older age has been associated with prolonged mechanical ventilation after coronary artery bypass surgery. Prolonged mechanical ventilation contributes to increased morbidity and mortality and to use of limited financial resources among older adults. To examine selected physiological and pathophysiological variables ofpresurgicalpatients to predict duration of mechanical ventilation in older adults after coronary artery bypass surgery. Nonrandomized study of a clinical database of 919 patients (> or =65 years old) who had coronary artery bypass surgery between October 1996 and December 1997. Median elapsed time after coronary artery bypass surgery until extubation was used to sort patients into 2 groups: group 1, 6 hours or fewer (n = 464); and group 2, more than 6 hours (n = 455). With stepwise logistic regression, the physiological model included age (odds ratio, 1.05; P<.001) and female sex (odds ratio, 1.48; P = .005) with weak discrimination by group (concordance statistic = 0.5880). The pathophysiological model, which included renal insufficiency (odds ratio, 3.28; P = .01), previous peripheral vascular surgery (odds ratio, 2.87; P = .03), nonelective preoperative clinical status (odds ratio, 2.8; P = .006), congestive heartfailure (odds ratio, 2.6; P<.001), and reoperation (odds ratio, 2.34; P = .007), showed moderate discrimination bygroup (concordance statistic =0.6755). Many older adults were easily extubated and had good outcomes. The variables comorbid conditions and severity of illness provided better discrimination between extubation groups than a physiological model provided. Both predictive models allowed limited discrimination between groups.

Early extubation after cardiac surgery: Emotional status in the early postoperative period

Objective: To compare the emotional state during the first 3 days after coronary artery surgery of patients who had undergone early versus conventional extubation. Design: A prospective, randomized, controlled trial. Setting: University hospital, single center. Participants: Eligible patients (n = 100) presenting for elective coronary artery surgery, randomized to an early extubation group or a conventional extubation group. Interventions: Emotional status was measured by the Hospital Anxiety and Depression Scale (HAD), the Self Assessment Manikin (SAM), and the Multiple Affect Adjective Check List-Revised (MAACL-R). Tests were administered preoperatively and on the 1st and 3rd days postoperatively. Measurements and Main Results: Of patients in the conventional extubation group, 30% showed moderate-to-severe depressive symptoms (HAD score >10) on day 3 postoperatively compared with 8% of patients in the early extubation group (p = 0.02). There was a clinically insignificant increase in MAACL-R depression score on the 1st postoperative day within both groups but no other differences within or between groups in SAM or MAACL-R scores. Conclusion: Early extubation results in fewer patients displaying depressive symptoms on the 3rd postoperative day but appears to have little effect on other measurements of emotional status. Anesthetic management during coronary artery bypass graft surgery may play an important role in the overall well-being of the patient by decreasing the incidence of postoperative depression. Copyright © 2001 by W.B. Saunders Company

Comparison of the Incidence of Complications at Induction and Emergence In Infants Receiving Oral Atropine vs. No Premedication

We studied 120 patients less than 1 yr of age, allocated randomly to receive atropine 40 micrograms kg-1 orally 1 h before operation (group A) or no premedication (group B). All patients underwent a standardized anaesthetic, including inhalation induction with halothane followed by atracurium 0.5 mg kg-1, tracheal intubation and positive pressure ventilation. Monitoring during anaesthesia included heart rate, arterial oxygen saturation, temperature and airway conditions at induction and emergence. The incidence of a decrease in arterial oxygen saturation to 94% or less at induction and recovery was similar in both groups (30.5% at induction, 39% at extubation in group A; 31% at induction, 41% at extubation in group B). There were significantly more airway complications in group B both at induction and emergence (25% and 49%, respectively, compared with 9% and 25% in group A; P or = 20%) at induction in the non-premedicated group (23% in group B compared with 10% in group A), but this was not statistically significant. We conclude that the incidence of airway complications at induction and emergence was reduced by orally administered atropine premedication.

Predictive risk factors for delayed extubation in patients undergoing coronary artery bypass grafting.

Prolonged mechanical ventilation increases hospitalization costs, airway and lung trauma, and stress. The objective of this study was to elucidate patient characteristics and operative variables that predict delayed extubation in patients undergoing coronary artery bypass grafting (CABG). The records of 167 patients who underwent CABG between 1994 and 1998 were examined retrospectively. The patients were divided into early and delayed extubation groups. Putative factors affecting the duration of intubation were included in a univariate analysis using the t-test and chi-squared test. A logistic regression model was then developed to determine the factors associated with delayed extubation. Forty-four percent of the patients needed prolonged mechanical ventilation (more than 24h). Univariate predictors of delayed extubation (P < 0.05) were emergency surgery, preoperative use of an intra-aortic balloon pump (IABP), the duration of anesthesia, surgery, cardiopulmonary bypass and aortic cross-clamping, the total volume of fentanyl. lowest rectal temperature, glucose level, perioperative transfusion, bleeding, perioperative heart failure, perioperative insertion of IABP, postoperative transfusion, cardiac index, inspired oxygen fraction (FiO2), arterial oxygen tension (PaO2), the PaO2/FiO2 ratio, and the volume of catecholamine. In the delayed extubation group, the intensive care unit stay was significantly longer (P < 0.001) and re-exploration was required more frequently (P = 0.004). Excellent prediction was provided by a model consisting of six variables: age, duration of surgery, perioperative heart failure, glucose level, postoperative transfusion, and the PaO2/FiO2 ratio. These results suggest that decreasing the cardiopulmonary bypass time, maintaining a low glucose level during cardiopulmonary bypass, and ensuring adequate perioperative hemostasis may help to avoid pulmonary dysfunction and delayed extubation. Moreover, the PaO2/FiO2 ratio may be a useful predictor of delayed extubation in patients undergoing CABG.

Comparison of the incidence of complications at induction and emergence in infants receiving oral atropine vs no premedication

We studied 120 patients less than 1 yr of age, allocated randomly to receive atropine 40 micrograms kg-1 orally 1 h before operation (group A) or no premedication (group B). All patients underwent a standardized anaesthetic, including inhalation induction with halothane followed by atracurium 0.5 mg kg-1, tracheal intubation and positive pressure ventilation. Monitoring during anaesthesia included heart rate, arterial oxygen saturation, temperature and airway conditions at induction and emergence. The incidence of a decrease in arterial oxygen saturation to 94% or less at induction and recovery was similar in both groups (30.5% at induction, 39% at extubation in group A; 31% at induction, 41% at extubation in group B). There were significantly more airway complications in group B both at induction and emergence (25% and 49%, respectively, compared with 9% and 25% in group A; P < 0.015). Mean heart rate at induction and in the peroperative period was significantly higher in the group receiving atropine (P < or = 0.001). There was an increased incidence of bradycardia (decrease in heart rate of > or = 20%) at induction in the non-premedicated group (23% in group B compared with 10% in group A), but this was not statistically significant. We conclude that the incidence of airway complications at induction and emergence was reduced by orally administered atropine premedication.

EPIDURAL ANALGESIA DURING MINIMALLY INVASIVE DIRECT CORONARY ARTERY BYPASS (MIDCAB) SURGERY IMPROVES PATIENT OUTCOME

Introduction. In MIDCAB surgery there is currently no agreement about the timing of extubation and the use of regional anesthetic techniques. [1] To investigate the effects of epidural analgesia and extubation in the operating room we prospectively analyzed blood gas variables, hemodynamics, pain score, length of hospital stay and myocardial infarction rate in 60 patients after MIDCAB surgery. Methods. Patients were randomized into 3 groups. Group A (n=20) were extubated immediately after the operation. Group B (n=20) had an epidural catheter placed at T3-4 before induction of anesthesia and were extubated immediately after the operation. Group C (n=20) served as controls and were left intubated and mechanically ventilated after the operation. Anesthesia consisted of midazolam, propofol, sufentanil and pancuronium. Epidural analgesia was achieved with bupivacain/sufentanil. A pulmonary artery catheter was inserted. Extubated patients received 40% oxygen by face mask. Pain management consisted of intramuscular opiates. A bupivacain/sufentanil infusion was used in the epidural group. Blood gas analysis and hemodynamic measurements were performed after induction of anesthesia, at end of operation and the morning of the first postoperative day. Results. Patient groups were comparable with respect to age, body surface, ejection fraction, previous infarction and previous PTCA. Main results are shown in Table 1.Table 1: Values are mean +/- SD. *= P<0.05 vs group C; $=P<0.05 vs group B; ANOVA.Discussion. The epidural-based anesthetic technique with direct postoperative extubation in group B resulted in optimal oxygenation and hemodynamics on the first postoperative day. This is probably the combined result of good analgesia allowing for adequate respiration and a sympathetic blockade as seen from a lower mean arterial pressure and lower heart rate with preservation of cardiac output. [2] However, at the end of operation a mild respiratory acidosis was observed in group A and B. This was in the epidural group B not accompanied by an increase in heart rate and mean arterial pressure. We conclude that an epidural-based anesthetic technique with direct postoperative extubation after MIDCAB surgery results in improved patient outcome.

POST-OPERATIVE PULMONARY FUNCTION IN CABG PATIENTS UNDERGOING EARLY TRACHEAL EXTUBATION

INTRODUCTION. Early extubation after CABG surgery has been shown to be safe and decreases postop LOS and hospital costs. [1,2] There is limited information of the impact of early extubation on pulmonary function and the ideal time to extubate these patients is controversial. We designed a clinical trial to evaluate the impact of a short period of postop mechanical ventilation vs immediate extubation on pulmonary function. METHODS. Institutional and ethics approval was obtained. The study population consisted of patients scheduled for elective CABG surgery. Patients with significant valvular disease, previous cardiac surgery, EF <or=to 30%, FEV1/FVC <or=to 60%, renal insufficiency, or an abnormal CXR were excluded. Informed consent was obtained. 35 patients were prospectively enrolled and randomized to 1 of 2 groups. Patients in Group I were extubated as soon as possible after surgery (n=18). Patients in Group II were sedated and ventilated for three hrs after surgery (n=17). Both groups were extubated after achieving predetermined extubation criteria. All patients received a standard anesthetic. Serial PFTs were performed (preop and on postop Day 1 and Day 3) using the helium dilution technique. Serial ABGs (pre- and postop) and serial CXR (preop, 4 hrs after extubation, and postop Day 1 and Day 2) were obtained. CXRs were evaluated for pleural changes, pulmonary edema and degree of atelectasis. Both the radiologist and respiratory therapist were blinded to the study group. Two way ANOVA was used to determine differences between times and groups. Between group comparisons of parametric data was assessed with the Students t-tests (unpaired). Chi-square tests were used to compare frequency data. RESULTS. Demographic data were comparable between groups. The mean time to extubation in Group I was 46 min +/- 28 min vs 201 min +/- 21 min in Group II (n = 16 & 16 respectively). There was a significant decline in postop pulmonary function tests in both groups, but there was no difference between groups at either 24 or 72 hrs postop (Table 1). There were no differences in postop ABGs after 2 hrs, atelectasis scores, or postop complications (data not shown).Table 1DISCUSSION. The data indicate that short term mechanical ventilation does not improve postop pulmonary function. Patients can be safely extubated shortly after CABG surgery without added pulmonary dysfunction.

Evaluation of routine tracheal extubation in children: inflating or suctioning technique?

We studied prospectively the effects of the technique of tracheal extubation on arterial haemoglobin oxygen saturation (SpO2) in 120 ASA I-III children, mean age 5.3 (range 0.25-16.9) yr. At completion of surgery, tracheal extubation was performed when spontaneous ventilation had resumed, children were fully awake and SpO2 was 99-100%. Children were allocated randomly to receive a single lung inflation manoeuvre with 100% oxygen before tracheal extubation (group I; n = 59) or to have the tracheal tube removed while applying suction through the tube (group S; n = 61). SpO2 was monitored during the first 5 min after tracheal extubation in the operating room. Supplementary oxygen was given if SpO2 decreased to less than 92%. The time between tracheal extubation and decrease in SpO2 to 92% (T92) was recorded. Children in group S required oxygen administration more frequently after tracheal extubation than those in group I (65.6% vs 45.8%; P = 0.04), and had a three-fold shortening of T92 (mean 25 (SD 19) s vs 85 (63) s; P = 0.0001). These effects were more pronounced in children less than 4 yr of age compared with older children. We conclude that tracheal extubation greatly impaired oxygenation and therefore administration of oxygen was appropriate. This impairment was more marked when suction was used, and in young children. Lung inflation with 100% oxygen before removal of the tracheal tube is advised before routine tracheal extubation in children.

Early Extubation Following Coronary Artery Bypass Surgery: A Prospective Randomized Controlled Trial

To determine the safety of early extubation (EE) after coronary artery surgery. Prospective randomized controlled trial. The cardiac surgery operating room and ICU of a university-affiliated teaching hospital. One hundred eligible patients presenting for elective coronary artery surgery. Patients randomized to the EE group were administered a reduced dose of fentanyl (15 microg/kg) and an anesthetic compatible with EE, while patients randomized to the conventional extubation (CE) group were given fentanyl (50 microg/kg). The time to extubation in the EE group (median, 240 min; range, 30 to 930 min) was significantly less than the CE group (median, 420 min; range, 125 to 1,140 min) (p<0.01). Twenty patients were withdrawn from the study according to protocol guidelines. There were no cases of reintubation or complications attributable to EE. By using an appropriate anesthetic technique and postoperative management, EE can be achieved following coronary artery bypass surgery without major complications.

Partial Liquid Ventilation (PLV) combined with Proportional Assist Ventilation (PAV) in Spontaneously Breathing Animals: Follow-up of Gas Exchange and Survival over a Four Week Period in a Rabbit Model 1673

This study tests the hypothesis that animals can be returned safely to gas ventilation after assisted ventilation with PLV combined with PAV.Methods: Nine anesthetized and intubated adult rabbits were ventilated using PAV with an FiO2 of 1.0 and a PEEP of 6 [4-6] cmH2O. The degree of unloading was adjusted to compensate approximately for the resistance of the endotracheal tube and to maintain a PaCO2 of 40-50 mmHg. An arterial femoral line was placed for blood gas measurements. Then a single dose of 30 ml/kg Perfluorocarbon (PFC), (Rimar 101) was instilled continuously into the endotracheal tube (rate 0.5ml/kg/min). The first two animals (early extubation group) were extubated after PaO2 had returned to baseline (approximately after 1 1/2 h); in subsequent animals(late extubation group; n=7) FiO2 was weaned after 3 h from 1.0 to 0.21 and animals were extubated after 5 h. Arterial blood gases were obtained in hourly intervals as well as 1 h, 12 h and 28 days after extubation. Weight gain was assessed in weekly intervals. Results: The two early extubated animals died within 48 h. Lung autopsy showed severe local emphysema in non-dependent regions, suggesting that evaporation had been incomplete, resulting in overdistension of non-dependent ventilated areas. 2/7 animals of the late extubation group died (one from a pneumothorax immediately after extubation and another for unknown reasons). Both did not show any evidence for pulmonary emphysema on autopsy. The other 5 animals were longterm survivors and showed progressive weight gain (106 ± 97 g/wk).Conclusion: Animals may be returned safely to gas ventilation after being supported with PLV combined with PAV if evaporation of PFC is complete. Table

Relationship of age, sex, and procedure type to extubation outcome after heart surgery

OBJECTIVE: To identify the relationship of age, sex, and type of procedure to extubation outcome (≤ 8 hours or > 8 hours), and to identify barriers to extubation after heart surgery. DESIGN: Quasi-experimental, prospective study. SETTING: Ten-bed cardiothoracic intensive care unit. SAMPLE: Sixty-two consecutive patients undergoing heart surgery. OUTCOME MEASURES: Early (≤ 8 hours) versus delayed (> 8 hours) extubation. RESULTS: Patients in the delayed extubation group were older (69.1 ± 11.3 years) than the patients in the early extubation group (59.6 ± 8.0 years, p = 0.01). Univariate logistic regression comparing age (<70 or ≥ 70 years), sex, and procedure (coronary artery bypass graft or other procedure) identified only age 70 years or older as a predictor of delayed extubation. The unadjusted odds ratio of delayed extubation in patients 70 years or older was 11.25. CONCLUSIONS: Age is a powerful predictor of delayed extubation after heart surgery. Only postoperative somnolence distinguished barriers to extubation in younger and older patients.

Early vs Conventional Extubation After Cardiac Surgery With Cardiopulmonary Bypass

Sedation and ventilation overnight after cardiac surgery is common practice. However, early extubation may be feasible with no increase in postoperative complications. This study examines (1) if early extubation is possible in a significant number of patients, (2) if it reduces ICU stay, and (3) if this practice increases postoperative complications. Prospective, controlled, randomized clinical trial. We randomized 404 consecutive patients to early extubation (7 to 11 h postoperatively) (group A, 201 patients) or conventional extubation (between 8 and 12 AM the following day) (group B, 203 patients). Variables included type and severity of the disease, surgical risk, type of operation, operative incidences, postoperative complications, duration of mechanical ventilation, intubation and ICU stay, bleeding, reoperation, vasoactive drugs, and mortality. Groups were comparable. Extubation within the preestablished time was successful in 60.2% of patients in group A and 74.4% in group B. Median ICU stay was 27 h in group A and 44 h in group B (p=0.008). Discharge from ICU within the first 24 h postoperatively was 44.3% in group A and 30.5% in group B (p=0.006). There was no significant difference in complications between groups. Successfully extubated patients in group A had more reintubation and prolonged ventilation than in group B. (1) Sixty percent of our patients were extubated within 11 h of operation. (2) As a result, the length of stay in ICU was reduced and the percentage of patients discharged within 24 h was increased. (3) There was no increase in clinically important postoperative complications.

Effect of Failed Extubation on the Outcome of Mechanical Ventilation

To examine medical outcomes associated with reintubation for extubation failure after discontinuation of mechanical ventilation. Prospective cohort study of consecutive intubated medical ICU patients who underwent a trial of extubation at a tertiary-care teaching hospital. The failed extubation group consisted of all patients reintubated within 72 h or within 7 days (if continuous ICU care had been required) of extubation. All others were considered to be successfully extubated. Study end points included hospital death vs survival, the number of days spent in the ICU and in the hospital after the onset of mechanical ventilation, the likelihood of requiring > or = 7 or > or = 14 days of ICU care after extubation, and the need for transfer to either a long-term care or rehabilitation facility among the survivors. Of 289 intubated patients, 247 (85%) were successfully extubated, and 42 (15%) required reintubation for failed extubation (time to reintubation 1.5+/-0.2 days). Reintubation for extubation failure resulted in 12 additional days of mechanical ventilation. When compared with successfully extubated patients, reintubated patients were more likely to die in the hospital (43% vs 12%; p<0.0001), spend more time in the ICU (21.2+/-2.8 days vs 4.5+/-0.6 days; p<0.001) and in the hospital (30.5+/-3.3 days vs 16.3+/-1.2 days; p<0.001) after extubation, and require transfer to a long-term care or rehabilitation facility (38% vs 21%; p<0.05). Using multiple logistic regression, extubation failure was an independent predictor for death and the need for transfer to a long-term care facility. Compared with those successfully extubated, patients who failed extubation were seven times (p<0.0001) more likely to die, 31 times (p<0.0001) more likely to spend > or = 14 days in the ICU after extubation, and six times (p<0.001) more likely to need transfer to a long-term care or rehabilitation facility if they survived. After adjusting for severity of illness and comorbid conditions, extubation failure had a significant independent association with increased risk for death, prolonged ICU stay, and transfer to a long-term care or rehabilitation facility. Extubation failure may serve as an additional independent marker of severity of illness. Alternatively, poor outcomes may be etiologically related to extubation failure. If the latter proves to be the case, identifying patients at risk for poor outcomes from extubation failure and instituting alternative care practices may reduce mortality, duration of ICU stay, and need for transfer to a long-term care facility.

Respiratory outcomes with early extubation after coronary artery bypass surgery

Objective: Aortocoronary bypass surgery has undergone recent changes, promoting the concept of “fast tracking”, in which patients are extubated and discharged postoperatively at an accelerated pace compared with previous historic patterns. Postoperative respiratory function and complications have not been previously studied in patients selected for “fast tracking”. Design: Matched retrospective cohort study. Setting: Referral university teaching hospital. Patients: Thirty-one patients who were compared with a retrospective matched cohort of 112 patients. Matching was based on forced vital capacity, age, and gender. Interventions: Respiratory physiological outcomes defined as pneumonia, postoperative pulmonary spirometry, chest x-ray atelectasis or lobar collapse, and gas exchange were compared. Main Results: The increase in atelectasis score compared with preoperative (0 = no atelectasis, 4 = lobar collapse) was higher ( p < 0.01) on the day of extubation in the late extubation group (4.1 ± 1.4) compared with the early extubation group (2.6 ± 1.3). These chest radiographic findings were not related to pain (0 to 10 visual analog scale), which were equivalent between groups (4.0 ± 2.3 v4.2 ± 1.6). The decreases in spirometry on postoperative day 5 (FVC 1.15 ± 0.42 vO.86 ± 0.54 liters; FEV 1 0.92 ± 0.38 v0.59 ± 0.50 liters) were greater ( p < 0.001) in the late extubation group. A significantly ( p < 0.001) greater decrease in FEV 1/FVC ratio in the late extubation group (3.25 ± 0.87 v−1.6 ± 1.11%) was indicative of greater airway obstruction. Fluid balance until extubation was greater in the late extubation group (4.0 ± 2.1 v 1.4 ± 1.2 liters). Conclusions: Differences in chest radiographs in the late extubation group at the time of extubation may be related to greater use of fluids or increased airway obstruction. The rationale of early extubation is based on cost minimization to decrease hospital duration. This article suggests that respiratory physiological outcomes are not worsened in patients who are extubated and discharged early after elective aortocoronary bypass surgery.

Determinants of prolonged mechanical ventilation after coronary artery bypass grafting

Early extubation of cardiac surgical patients enhances ambulation, improves cardiopulmonary function, and can lead to savings in health care costs. We retrospectively examined the role of 48 variables in determining the period of ventilatory support in 507 patients having coronary artery bypass grafting. Fifteen (< 3%) of 507 patients required ventilatory support in excess of 24 hours. Among the remaining patients, extubation was achieved early (< or = 8 hours) (mean time, 5.65 +/- 1.31 hours) in 53% and late (> 8 hours) (mean time, 13.7 +/- 3.4 hours) in 47%. Logistic and linear multivariate regression analyses implicated increased age, New York Heart Association functional class IV, intraoperative fluid retention, postoperative intraaortic balloon pump requirement, and bank blood transfusions as predictors of late extubation. Also, the linear regression linked lower body weight and number of anastomoses (or grafts) to increased mechanical ventilatory support. Analysis of the fluid balance and cardiopulmonary bypass data suggests that earlier extubation may be achieved by actively reducing fluid retention (eg, by hemoconcentration) and time on bypass (eg, normothermia). Finally, intensive care unit stay and postoperative length of stay were significantly lower in the early versus late extubation groups without an increase in pulmonary complications.

Morbidity outcome in early versus conventional tracheal extubation after coronary artery bypass grafting: A prospective randomized controlled trial

Introduction: We undertook a prospective, randomized, controlled clinical trial to evaluate morbidity outcomes and safety of a modified anesthetic technique to provide shorter sedation and early extubation (1 to 6 hours) than those of the conventional anesthetic protocol used for prolonged sedation and extubation (12 to 22 hours) in patients after coronary artery bypass grafting. Methods: One hundred twenty patients undergoing elective coronary artery bypass grafting were prospectively assigned randomly to either an early extubation group ( n = 60; 15 μg·kg -1 fentanyl and 2 to 6 mg · kg -1· hour -1 propofol and isoflurane) or to a conventional extubation group ( n = 60; 50 μg·kg -1 fentanyl and 0.1 mg·kg -1 midazolam and isoflurane). Cardiac morbidity (postoperative myocardial ischemia, postoperative myocardial infarction, and perioperative sympathoadrenal stress response), respiratory morbidity (postextubation apnea, alveolar-arterial oxygen gradient, pulmonary shunting, oxygen consumption, atelectasis, and reintubation), hemodynamic values and vasoactive medication requirements, intraoperative awareness, postoperative cognitive function, 30 day mortality, and intensive care unit and hospital lengths of stay were compared between the two groups. Results: Fifty-one of the 60 patients in each group (85%) were extubated within the defined time period. Postoperative extubation time and intensive care unit and hospital lengths of stay were significantly shorter in the early group. At 48 hours after operation, there were no significant differences between the two groups in myocardial ischemia incidences, ischemia burdens, or creatine kinase isoenzyme MB levels. Four patients in the conventional group, but not in the early group, had postoperative myocardial infarction. The extubation anesthetics used were effective in suppressing the perioperative plasma catecholamine stress response in both groups. Postextubation apnea characteristics were similar between the groups. Intrapulmonary shunt fraction improved significantly in the early group at 4 hours after extubation. The incidences and degree of atelectasis did not differ significantly between the two groups. The incidences of treated postoperative complications were comparable between the two groups, but three patients in the conventional group died as a result of stroke or postoperative myocardial infarction. Conclusion: Early extubation after coronary artery bypass grafting is safe and does not increase perioperative morbidity. There is an improvement in postextubation intrapulmonary shunt fraction and a reduction in intensive care unit and hospital lengths of stay. (J T HORAC C ARDIOVASC S URG 1996;112:755-64)

Closed mitral valvotomy and elective ventilation in the postoperative period: Effect of mild hypercarbia on right ventricular function

It is customary to extubate patients immediately after closed mitral valvotomy. These patients often have deranged respiratory function caused by chronic lung congestion. The left ventricular function may also be subnormal after valvotomy in some patients. Therefore, elective ventilation for some duration in the postoperative period can be beneficial to these patients. This work is an attempt to find whether elective ventilation should be preferred over immediate extubation in these patients. A prospective randomized study. The study was performed in a tertiary care hospital, and the patients are referred from the northern states of India. One hundred patients undergoing elective closed mitral valvotomy were included in the initial part of the study. Ten more patients were studied to evaluate the effect of mild hypercarbia on right ventricular function after closed mitral valvotomy. One hundred patients were divided into two groups of 50 each. Group 1 consisted of patients in whom the neuromuscular blockade was reversed at the end of surgery with neostigmine and atropine and the trachea was extubated. In group 2, the residual neuromuscular paralysis was not reversed and the patients were electively ventilated in the postoperative period for an average duration of 5 hours and 29 minutes +/- 1 hour and 58 minutes. In all the patients in both the groups, electrocardiogram, direct arterial blood pressure, and oxygen saturation were continuously monitored, and arterial blood gases were measured intermittently throughout the study period. Because the results showed that there was mild hypercarbia, 30 minutes after extubation in group 1, 10 more patients were studied to evaluate the effect of mild hypercarbia on right ventricular function after surgery. Patients were ventilated after surgery (F1O2 = 1) to maintain normocarbia (PaCO238.6 +/- 3.4 mmHg). Mild hypercarbia PaCO251.5 +/- 3.7 mmHg) followed by normocarbia (PaCO2 40 +/- 2.5 mmHg) was induced by adjusting the ventilator rate with a constant tidal volume. Standard hemodynamic measurements were performed at each stage. Although all the patients maintained satisfactory and stable hemodynamics in the postoperative period, the PaCO2 at the end of 30 minutes of extubation was significantly higher in group 1 (48.1 +/- 5.3 mmHg) as compared with group 2 (40.2 +/- 4.3 mmHg, p < 0.001). Mild hypercarbia significantly increased pulmonary vascular resistance (p < 0.01), mean pulmonary arterial pressure (p < 0.001), right ventricular stroke work (p < 0.01), right ventricular systolic pressure (p < 0.01), and right ventricular end-diastolic pressure (p < 0.001). The effect was not totally reversible with CO2 washout as all parameters except right ventricular end-diastolic pressure and pulmonary vascular resistance continued to remain significantly higher when normocarbia was restored. The significant changes in systemic hemodynamics produced by hypercarbia were increases in cardiac index, mean arterial pressure, and pulmonary capillary wedge pressure. Avoidance of even mild hypercarbia, therefore, appears advisable in the early postoperative period because of potential impedence to right ventricular ejection. Continuous monitoring of end-tidal CO2 and frequent blood gas analyses should be practiced, and elective ventilation should be considered in patients with long-standing disease and pulmonary hypertension.