Cluster randomized trial to evaluate the impact of team training on surgical outcomes

Background

The application of safety principles from the aviation industry to the operating room has offered hope in reducing surgical complications. This study aimed to assess the impact on major surgical complications of adding an aviation-based team training programme after checklist implementation.

Methods

A prospective parallel-group cluster trial was undertaken between September 2011 and March 2013. Operating room teams from 31 hospitals were assigned randomly to participate in a team training programme focused on major concepts of crew resource management and checklist utilization. The primary outcome measure was the occurrence of any major adverse event, including death, during the hospital stay within the first 30 days after surgery. Using a difference-in-difference approach, the ratio of the odds ratios (ROR) was estimated to compare changes in surgical outcomes between intervention and control hospitals.

Results

Some 22 779 patients were enrolled, including 5934 before and 16 845 after team training implementation. The risk of major adverse events fell from 8·8 to 5·5 per cent in 16 intervention hospitals (adjusted odds ratio 0·57, 95 per cent c.i. 0·48 to 0·68; P < 0·001) and from 7·9 to 5·4 per cent in 15 control hospitals (odds ratio 0·64, 0·50 to 0·81; P < 0·001), resulting in the absence of difference between arms (ROR 0·90, 95 per cent c.i. 0·67 to 1·21; P = 0·474). Outcome trends revealed significant improvements among ten institutions, equally distributed across intervention and control hospitals.

Conclusion

Surgical outcomes improved substantially, with no difference between trial arms. Successful implementation of an aviation-based team training programme appears to require modification and adaptation of its principles in the context of the the surgical milieu. Registration number: NCT01384474 (http://www.clinicaltrials.gov).

Safety of oral nicorandil before coronary artery bypass graft surgery

Nicorandil is a K(ATP) channel opener used to treat angina. It is cardioprotective and a vasodilator. We conducted a prospective, randomized, double-blind, placebo-controlled study to assess oral nicorandil in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). Twenty-two patients received nicorandil (10 mg twice a day) and 23 patients received placebo. Haemodynamic data were recorded before induction of anaesthesia (T0), 5 and 20 min after starting mechanical ventilation (T1, T2), before aortic cannulation (T3), after 30 min of CPB (T4), 10 min after CPB (T5) and after 3, 8 and 18 h in the intensive care unit (T6, T7, T8). Serum proteins (creatine kinase metabolite and cardiac troponin I) were measured before and 8 and 18 h after surgery. Haemodynamic values did not differ between the two groups. There was no tachycardia during the study, no significant difference in hypotensive episodes, ST segment changes and no changes in cardiac enzymes. Myocardial infarction after surgery was similar in the two groups. Vasoactive therapy was similar in the two groups. Nicorandil can be continued safely up to premedication without deleterious haemodynamic consequences, but a myocardial protective effect of nicorandil in CABG surgery was not found.

[Surgery of active-phase infective endocarditis: report of 13 cases]

OBJECTIVE

Infective endocarditis is always a disease at the present time. In this work we report our initial experience of infective endocarditis surgical treatment during the acute phase.

METHODS AND RESULTS

Between September 1993 and December 1997, 13 patients underwent valvular surgery for native infective endocarditis. Mean age was 31 +/- 11 years (range: 9 to 42 years); 92.3% of the patients presented with pre-existing rheumatical valvular lesion. Surgical indication was the occurrence of heart failure in all these patients. Surgery consisted on aortic valvular replacement in four patients, mitral and aortic valvular replacement in nine patients. Tricuspid valvuloplasty was required in two patients. Early mortality was 15% (two patients). A third patient developed cardiac failure and died three years postoperatively.

CONCLUSION

This work emphasises the interest of the surgical treatment in the active phase of the infective endocarditis.

Cardiac surgery with cardiopulmonary bypass in patients with type II heparin-induced thrombocytopenia

BACKGROUND

The use of cardiopulmonary bypass (CPB) in patients with a history of type II heparin-induced thrombocytopenia (HIT) may be associated with complications related to their anticoagulation management.

METHODS

Between January 1997 and December 1999, among 4,850 adults patients who underwent cardiac surgery in our institution, 10 patients presented with preoperative type II HIT. In 4 patients, anticoagulation during CPB was achieved with danaparoid sodium. In 6 other patients, heparin sodium was used after pretreatment with epoprostenol sodium.

RESULTS

No significant change in platelet count occurred in any patient. No intraoperative thrombotic complication was encountered. Total postoperative chest drainage ranged from 250 to 1,100 ml in patients pretreated with epoprostenol and 1,700 to 2,470 ml in patients who received danaparoid sodium during CPB (p < 0.05, Mann-Whitney U test).

CONCLUSIONS

During CPB, inhibition of platelet aggregation by prostacyclin may be a safe anticoagulation approach in patients with type II HIT.

Usefulness of procalcitonin for diagnosis of infection in cardiac surgical patients

OBJECTIVE

To determine the value of procalcitonin (PCT) as a marker of postoperative infection after cardiac surgery.

DESIGN

A prospective single institution three phase study.

SETTING

University cardiac surgical intensive care unit (31 beds).

PATIENTS

Phase 1: To determine the normal perioperative kinetics of PCT, 20 consecutive patients undergoing elective cardiac surgery with cardiopulmonary bypass were included. Phase 2: To determine whether PCT may be useful for diagnosis of postoperative infection, 97 consecutive patients with suspected infection were included. Phase 3: To determine the ability of PCT to differentiate patients with septic shock from those with cardiogenic shock, 26 patients with postoperative circulatory failure were compared.

MEASUREMENTS AND MAIN RESULTS

Phase 1: Serum samples were drawn for PCT determination after induction of anesthesia (baseline), at the end of surgery, and daily until postoperative day (POD) 8. Baseline serum PCT concentration was 0.17 +/- 0.08 ng/mL (mean +/- SD). Serum PCT increased after cardiac surgery with a peak on POD 1 (1.08 +/- 1.36). Serum PCT returned to normal range on POD 3 and remained stable thereafter. Phase 2: In patients with suspected infection, serum PCT was measured at the same time of C-reactive protein (CRP) and bacteriologic samples. Among the 97 included patients, 54 were infected with pneumonia (n = 17), bacteremia (n = 16), mediastinitis (n = 9), or septic shock (n = 12). In the 43 remaining patients, infection was excluded by microbiological examinations. In noninfected patients, serum PCT concentration was 0.41 +/- 0.36 ng/mL (range, 0.08-1.67 ng/mL). Serum PCT concentration was markedly higher in patients with septic shock (96.98 +/- 119.61 ng/mL). Moderate increase in serum PCT concentration occurred during pneumonia (4.85 +/-3.31 ng/mL) and bacteremia (3.57 +/- 2.98 ng/mL). Serum PCT concentration remained low during mediastinitis (0.80 +/- 0.58 ng/mL). Five patients with mediastinitis, two patients with bacteremia, and one patient with pneumonia had serum PCT concentrations of <1 ng/mL. These eight patients were administered antibiotics previously and serum PCT was measured during a therapeutic antibiotic window. For prediction of infection by PCT, the best cutoff value was 1 ng/mL, with sensitivity 85%, specificity 95%, positive predictive value 96%, and negative predictive value 84%. Serum CRP was high in all patients without intergroup difference. For prediction of infection by CRP, a value of 50 mg/L was sensitive (84%) but poorly specific (40%). Comparing the area under the receiver operating characteristic curves, PCT was better than CRP for diagnosis of postoperative sepsis (0.82 for PCT vs. 0.68 for CRP). Phase 3: Serum PCT concentration was significantly higher in patients with septic shock than in those with cardiogenic shock (96.98 +/- 119.61 ng/mL vs. 11.30 +/- 12.3 ng/mL). For discrimination between septic and cardiogenic shock, the best cutoff value was 10 ng/mL, with sensitivity of 100% and specificity of 62%.

CONCLUSION

Cardiac surgery with cardiopulmonary bypass influences serum PCT concentration with a peak on POD 1. In the presence of fever, PCT is a reliable marker for diagnosis of infection after cardiac surgery, except in patients who previously received antibiotics. PCT was more relevant than CRP for diagnosis of postoperative infection. During a postoperative circulatory failure, a serum PCT concentration >10 ng/mL is highly indicative of a septic shock.

[Perioperative beta-blockers. Part two: therapeutic indications]

PURPOSE

To review the pharmacologic and pathophysiologic information necessary to prescribe beta-blockers (BB) in perioperative medicine.

DATA SOURCE

Manual retrieval and electronic research of the literature using MEDLINE (key-words: anesthesia and beta- blocker; surgery and beta-blocker).

DATA SYNTHESIS

In non cardiac surgery, the beneficial effects of BB have been demonstrated in hypertensive patients since 1979. In 1996, the beneficial effects of atenolol in patients with coronary artery disease (reduction of postoperative myocardial ischemia and overall reduction in two-year mortality) were demonstrated. In coronary surgery, the interest of preoperative BB treatment has been shown since 1983. Administration of BB has been shown to be beneficial in acute myocardial infarction or chronic cardiac failure (except in NYHA class IV patients).

CONCLUSION

BB have been shown to exert a beneficial effect on postoperative outcomes in patients with cardiovascular disease or risk factors, and their more widespread use in perioperative medicine is encouraged.

[Perioperative beta-blockers. Part one: fundamentals]

PURPOSE

To review the pharmacologic and pathophysiologic information necessary to prescribe beta-blockers (BB) in perioperative medicine.

DATA SOURCE

Manual retrieval and electronic research of the literature using MEDLINE (key-words: anesthesia and beta- blocker; surgery and beta-blocker).

DATA SYNTHESIS

Cardioselective BB inhibit preferentially beta-1 receptors, inducing a decrease in heart rate and cardiac inotropism leading to reduction of oxygen myocardial consumption. Non-cardioselective BB inhibit also beta-2 receptors, increasing bronchial and peripheral vascular resistances and uterine contractions. However, some BB are also vasodilators (carvedilol, celiprolol, labetalol). Contraindications to BB result logically from their pharmacological effects. Treatment with BB increases membrane beta-receptor density; this explains sympathetic overactivity observed during weaning of treatment. Since the discovery of propranolol in 1964, the use of BB has been controversial in anesthesia. Formerly, the adverse effects of partial sympatholysis during anesthesia and surgery were feared. However, since 1973, experimental and clinical data have suggested a protective hemodynamic effect.

CONCLUSION

Continued administration of BB up to the time of anesthesia has been encouraged except in patients with signs of intolerance such as hypotension or excessive bradycardia.

Relative importance of flow versus pressure in splanchnic perfusion during cardiopulmonary bypass in rabbits

BACKGROUND

Decreased gastrointestinal perfusion has been reported during cardiopulmonary bypass (CPB). Conflicting results have been published concerning thresholds of pressure and flow to avoid splanchnic ischemia during CPB. This study compared splanchnic perfusion during independent and randomized variations of CPB pump flow or arterial pressure.

METHODS

Ten rabbits were studied during mild hypothermic (36 degrees C) nonpulsatile CPB using neonatal oxygenators. Simultaneous measurements of tissue blood flow in four different splanchnic areas (gastric, jejunum, ileum, and liver) were performed by laser Doppler flowmetry (LDF) before CPB (T0) and during a 4-step factorial experimental block design. Pressure and flow were alternatively high or low in random order.

RESULTS

Laser Doppler flowmetry was significantly lower than pre-CPB value but was better preserved (analysis of covariance) in all organs, except liver, when CPB flow was high, whatever the pressure. Splanchnic LDF values in the low- versus high-flow groups expressed as perfusion unit were (mean +/- SD): stomach, 94+/-66 versus 137+/-75; jejunum, 118+/-78 versus 172+/-75; ileum, 95+/-72 versus 146+/-83; and liver, 79+/-72 versus 108+/-118. No significant difference of LDF was observed between the high- and low-pressure groups, whatever the flow, except for liver: stomach, 115+/-64 versus 117+/-83; jejunum, 141+/-80 versus 148+/-83; ileum, 127+/-87 versus 114+/-76; liver, 114+/-88 versus 73+/-70.

CONCLUSION

Prevention of splanchnic ischemia during CPB should focus on preservation of high CPB blood flow rather than on high pressure.

Effects of intraoperative glucose administration on circulating metabolites and nitrogen balance during prolonged surgery

STUDY OBJECTIVES

To compare the effects of intraoperative administration of 2.5% glucose or Ringer's solution on metabolism during prolonged surgery.

DESIGN

Prospective, randomized study.

SETTING

Teaching hospital.

PATIENTS

20 ASA physical status I and II adults patients scheduled for thoracic or abdominal surgery lasting at least 3 hours.

INTERVENTIONS

Patients received Ringer's solution (Group R) or 2.5% glucose solution (Group G) 10 ml.kg-1.h-1 during surgery and 2 ml.kg-1.h-1 during the first two postoperative hours (Ringer's or glucose), then 40 ml.kg-1.day-1 of 5% intravenous (i.v.) glucose postoperatively.

MEASUREMENTS AND MAIN RESULTS

Plasma glucose, free fatty acids, ketone bodies, lactate, insulin, glucagon, cortisol, and growth hormone concentrations were determined after an overnight fast (T0), on induction of anesthesia (T1), at the end of surgery (T2), 2 hours thereafter (T3), and on the following morning (T4). Capillary blood glucose was determined every 30 minutes from T1 to T2. Urinary nitrogen and 3-methylhistidine were measured every day for 5 days. There were no differences between groups in demographic data, anesthesia, or surgical procedures. All data were comparable at baseline and on the following morning. In Group R, no patient experienced hypoglycemia, but plasma fatty acids and ketone bodies increased during surgery. In Group G, glycemia rose to very high levels, with a significant increase in insulin during surgery. Other hormones were the same within the two groups. Urinary nitrogen and 3-methylhistidine were similar in both groups.

CONCLUSION

The absence of glucose infusion in prolonged surgery did not cause hypoglycemia, and no increase in protein catabolism was observed.

Effect of cardiopulmonary bypass on serum procalcitonin and C-reactive protein concentrations

We have measured serum procalcitonin (PCT) concentrations after cardiac surgery in 36 patients allocated to one of three groups: group 1, coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) (n = 12); group 2, CABG without CPB (n = 12); and group 3, valvular surgery with CPB (n = 12). Serum PCT and C-reactive protein (CRP) concentrations were measured before operation, at the end of surgery and daily until postoperative day 8. Serum PCT concentrations increased, irrespective of the type of cardiac surgery, with maximum concentrations on day 1: mean 1.3 (SD 1.8), 1.1 (1.2) and 1.4 (1.2) ng ml-1 in groups 1, 2 and 3, respectively (ns). Serum PCT concentrations remained less than 5 ng ml-1 in all patients. Concentrations returned to normal by day 5 in all groups. To determine the effect of the systemic inflammatory response (SIRS) on serum PCT concentrations, patients were divided post hoc, without considering the type of cardiac surgery, into patients with SIRS (n = 19) and those without SIRS (n = 17). The increase in serum PCT was significantly greater in SIRS (peak PCT 1.79 (1.64) ng ml-1 vs 0.34 (0.32) ng ml-1 in patients without SIRS) (P = 0.005). Samples for PCT and CRP measurements were obtained from 10 other patients with postoperative complications (circulatory failure n = 7; active endocarditis n = 2; septic shock n = 1). In these patients, serum PCT concentrations ranged from 6.2 to 230 ng ml-1. Serum CRP concentrations increased in all patients, with no differences between groups. The postoperative increase in CRP lasted longer than that of PCT. We conclude that SIRS induced by cardiac surgery, with and without CPB, influenced serum PCT concentrations with a moderate and transient postoperative peak on the first day after operation. A postoperative serum PCT concentration of more than 5 ng ml-1 is highly suggestive of a postoperative complication.

[Minimally invasive cardiac surgery: surgical techniques and anesthetic problems]

OBJECTIVE

To review current data on minimally invasive cardiac surgery.

DATA SOURCES

Search through the Medline data base of French or English articles.

DATA EXTRACTION

The articles were analysed to make a synthesis of the various techniques with their main indications and contra-indications.

DATA SYNTHESIS

Minimally invasive cardiac surgery includes various surgical procedures. The usual techniques are described, their major benefits and drawbacks are discussed. The main goals of anaesthetic management are preservation of ventricular function and systemic perfusion, detection and treatment of myocardial ischaemia, prevention of hypothermia in case of coronary artery bypass grafting on the beating heart via sternotomy, intermittent selective ventilation of the collapsed lung using CPAP in case of limited thoracotomy. Expertise in transoesophageal echocardiography is essential for insertion and checking the accurate positioning of the various catheters of the endovascular CPB Heartport system (pulmonary vent, endosinus catheter, venous cannula, endoaortic clamp) allowing coronary artery bypass grafting and mitral valve surgery through limited thoracotomy and finally, detection of retained intracardiac air and assessment of complete clearing of cardiac cavities after mitral valve surgery through limited thoracotomy and aortic valve surgery via ministernotomy. Short-acting anaesthetic agents allow rapid recovery from anaesthesia, early extubation and discharge to the surgical ward within 24 h, whereas overall time spent in the operating room is often longer than with conventional cardiac surgery.

[Severe digestive complications after heart surgery using extracorporeal circulation]

PURPOSE

To determine the incidence, circumstances of occurrence and evolution of gastrointestinal complications after cardiac surgery with extracorporeal circulation (ECC).

METHODS

Retrospective chart study of gastrointestinal complications in 6.281 patients undergoing ECC between january 1994 and December 1997.

RESULTS

Sixty patients developed 68 gastrointestinal complications (1%). Complications included: upper gastrointestinal bleeding (n = 23), intestinal ischemia (n = 19), cholecystitis (n = 7), pancreatitis (n = 6), and paralytic ileus (n = 16). The incidence of these complications was low after coronary artery (0.4%) or valvular surgery (0.8%) and high after cardiac transplantation (6%) and after surgery for acute aortic dissection (9%). Compared with a control population, patients with gastrointestinal complication had a higher Parsonnet score (29 +/- 15 vs 13 +/- 12 points; P = 0.002), were more frequently operated upon as an emergency (40/60, 66% vs 1120/6221, 18%; P = 0.01), underwent ECC of longer duration (114 +/- 66 vs 74 +/- 42 min; P = 0.01), and presented more frequently with low cardiac output after surgery (45/60, 75% vs 435/6221, 7%; P = 0.001). The mortality rate after gastrointestinal complications was 52%. The major factor associated with mortality was the occurrence of sepsis (OR = 38.7). Other factors were: renal failure (OR = 7.9), age > 75 yr (OR = 3.5), mechanical ventilation for more than seven days (OR = 2.7), associated cerebral damage (OR = 3.9).

CONCLUSION

Gastrointestinal complications after ECC occur in high risk surgical patients. These complications are frequently associated with other complications leading to a high mortality rate.

Effects of dopexamine on blood flow in multiple splanchnic sites measured by laser Doppler velocimetry in rabbits undergoing cardiopulmonary bypass

Decreased gut perfusion has been reported during cardiopulmonary bypass (CPB). Studies of treatments to avoid splanchnic ischaemia during CPB have given conflicting results. We studied 12 rabbits during mild hypothermic non-pulsatile CPB. Tissue blood flow in three different splanchnic areas (gastric, jejunum and ileum) was measured by laser Doppler velocimetry (LDV) before CPB (T0), after steady state (T1), after administration of dopexamine 2 micrograms kg-1 min-1 (T2) and 4 micrograms kg-1 min-1 (T3), and after return to baseline (T4). Splanchnic blood flow decreased during CPB. Dopexamine increased significantly jejunum LDV (100% at T1 to mean 271 (SD 210)% at T2) and ileum LDV (100% at T1 to 187 (112)% at T2). Gastric LDV was not altered by infusion of dopexamine during CPB. This could partly explain the conflicting results on the value of gastric tonometry as an index of splanchnic injury.

[Non-steroidal anti-inflammatory agent and angiotensin converting enzyme inhibitor: a dangerous combination during postoperative period]

A 72-year-old man experienced a postoperative acute renal failure (ARF) from a nonsteroidal anti-inflammatory drug (NSAID) and an angiotensin converting enzyme inhibitor (ACEI) intake and promoted by an unrecognized myeloma, peroperative hypotension and hormonal response to surgical stress. This drug combination can result in ARF through a fall of glomerular filtration by combined renal blood flow changes: NSAID inhibit vasodilation by renal prostaglandins, and the vasoconstrictor effect on the efferent arteriole is inhibited by the ACEI. Nephrotoxicity during the simultaneous use of ACEI and NSAID is increased by other risk factors of renal insufficiency such as ageing, preexisting renal disease and hypovolaemia. In these cases, a preventive therapy should be considered.

Glucose versus lactated Ringer's solution during pediatric cardiac surgery

OBJECTIVE

Whether intraoperative fluid infusion should contain glucose during pediatric cardiac surgery remains controversial. This study was performed to compare the effects of glucose and glucose-free solutions on blood glucose and blood insulin levels during total repair of congenital heart diseases.

DESIGN

Prospective randomized and blinded study.

SETTING

Cardiovascular university center.

PARTICIPANTS

Forty nondiabetic children, weight ranging from 4 to 10 kg, scheduled for cardiac surgical procedures requiring cardiopulmonary bypass (CPB) without total circulatory arrest.

INTERVENTIONS

Group R (n = 20) was administered lactated Ringer's solution intraoperatively, and group G (n = 20) received 5% glucose. Fluids were infused at a rate of 3 mL/kg/h in the two groups from the induction of anesthesia to the end of the surgical procedure. Blood glucose and insulin were sampled before infusion (Tzero), before CPB (T1), 10 minutes after initiation of CPB (T2), 10 minutes after initiation of rewarming (T2), and at the end of the procedures (T4). Postoperatively, blood glucose was measured at the first, 12th, and 24th hours.

MEASUREMENTS AND RESULTS

During the prabypass period, three children in group R had severe hypoglycemia (blood glucose < 40 mg/dL). After initiation of CPB, blood glucose increased in both groups, with a small difference at the end of the procedure. No infants in the two groups had blood glucose higher than 239 mg/dL.

CONCLUSIONS

Glucose withdrawal during pediatric cardiac surgery induces threatening hypoglycemia during the prabypass period, and moderate intraoperative glucose administration (2.5 mg/kg/min) is not responsible for major hyperglycemia.