Compliance With Guidelines on Antibiotic Prophylaxis in Total Hip Replacement Surgery: Results of a Retrospective Study of 416 Patients in a Teaching Hospital

Objective:

To assess compliance of anesthesiologist practices in antibiotic prophylaxis during total hip replacement (THR) surgery with the French Society of Anesthesiology and Intensive Care consensus-based guidelines.

Design:

Retrospective review of medical records. Compliance of anesthesiologist practices with the guidelines was assessed according to antibiotic prophylaxis use, antimicrobial agent, dosage of first injection, time from first dose to incision, and total duration of antibiotic prophylaxis.

Setting:

Orthopedic surgery wards in a 2,200-bed French teaching hospital.

Patients:

A random sample of 416 patients undergoing THR from January 1999 to December 2000.

Results:

Three hundred eighty-six (93%) of the sampled medical records were usable. Antibiotic prophylaxis was used for 366 (95%) of the patients. Total duration of prophylaxis did not exceed 48 hours in 98% (359 of 366) of the patients. Drug selection complied with national guidelines in 259 (71%) of the patients. Dosage and timing of the first injection were appropriate in 98% (290 of 296) and 80% (236 of 296) of the patients, respectively, who received one of the recommended antibiotics. Overall, 53% (203 of 386) of the patients met all five criteria. In multivariate analysis, there was a significant anesthesiologist effect on overall compliance with the guidelines (likelihood ratio chi-square with 9 degrees of freedom, 25.7; P < .01). Undergoing surgery during 2000 was the only patient characteristic associated with an increased rate of appropriate practices (adjusted OR, 1.56; CI95,1.02-2.38).

Conclusion:

The overall compliance rate should be improved by disseminating the guidelines and the results of this study following audit and feedback.

Effect of aprotinin on postoperative blood loss in off-pump coronary artery bypass surgery

BACKGROUND AND AIM OF THE STUDY

Off-pump coronary artery bypass (OPCAB) enables a reduction in postoperative complications, particularly bleeding and transfusion. Nevertheless, a significant percentage of patients still needs transfusion. The effect of antifibrinolytic therapy on postoperative bleeding as part of OPCAB is still not widely described. The purpose of this study was to investigate the potential benefit of aprotinin in OPCAB.

METHODS

We conducted a retrospective comparative study with a historical control group. Consecutive patients undergoing off-pump coronary bypass were divided in two groups: 40 patients were operated without any antifibinolytic drug (group C); 40 patients received aprotinin (group A) during surgery. Patients in group A received a bolus of 2 x 10(6) KIU during 30 minutes, followed by a continuous infusion of 0.5 x 10(6) KIU per hour until the end of surgery. The same protocol was used during the whole study period.

RESULTS

Preoperative data of the two groups did not differ except for the number of grafts performed, which was higher in group A. Prothrombin time and activated clotting time increased in both groups after surgery. The use of packed red blood cells or fresh frozen plasma was not significantly different between both groups. Postoperative blood loss was significantly reduced in the aprotinin group (540 mL +/- 320 vs. 770 mL +/- 390, p = 0.006). No increase in postoperative troponin values was found in group A.

CONCLUSIONS

Aprotinin significantly reduced postoperative blood loss without reducing the transfusion rate. Aprotinin was not associated with any increase in postoperative complications.

Emergency endovascular stent graft repair for acute blunt thoracic aortic injury: a retrospective case control study

OBJECTIVE

To compare surgical and endovascular stent graft (ESG) treatment of blunt thoracic aortic injury (BAI) in the emergency setting.

DESIGN AND SETTING

Retrospective case control study in two surgical intensive care units of a university hospital.

PATIENTS

30 patients who presented with BAI between 1995 and 2005: 17 treated surgically and 13 by ESG. The two groups were comparable for the severity of trauma and mean delay before treatment; the mean age was higher in the ESG group (46+/-18 vs. 35+/-15 years).

RESULTS

In the surgical group time spent in the operating theater was longer (310+/-130 vs. 140+/-48 min) and blood losses higher (2000+/-1300 vs. no significant bleeding); aortic clamping time was 48+/-20 min. The mortality rate was 15% with ESG (n=2) and 23% with surgery (n=4). Complications of the procedure were more frequent in the surgical group (1 vs. 7). In the ESG group there was one pulmonary embolism. In the surgical group there were three neurological complications, one acute aortic dissection, one perioperative rupture, one periprosthetic leak, and one septic shock. Two complications (postoperative aortic dissection and paraplegia) appeared in the same patient in the surgical group. Intensive care unit length of stay, duration of mechanical ventilation, and catecholamine support were similar in the two groups.

CONCLUSIONS

Stent graft for emergency treatment of BAI is efficient and is associated with fewer complications than surgical treatment.

Right Ventricular Function After Coronary Surgery with or Without Bypass

BACKGROUND AND OBJECTIVE

Myocardial protection during aortic clamp period may sometimes be inadequate, especially for the right. The aim of this study was to compare right ventricle function after cardiac surgery with or without bypass.

METHODS

Patients undergoing multivessel coronary surgery with proximal severe right coronary lesion were included in a prospective observational cohort study including 29 patients undergoing coronary surgery with or without bypass. All patients were monitored with a pulmonary artery catheter with continuous right ventricular function. Right ventricular ejection fraction was measured at the arrival in ICU, 1, 3, 6, and 18 hours later.

RESULTS

The number of grafts that was higher in the bypass group (4.0 +/- 1.3) than in the off-pump group (2.6 +/- 0.6, p = 0.001). In the on-pump group, the right ventricular ejection fraction significantly decreased from 32.9 +/- 2.8 at arrival in ICU to 26.1 +/- 2.4, 6 hours later whereas in the off-pump group, it did not significantly change (32.4 +/- 1.8 to 31.9 +/- 2.3). Meanwhile, at the same time intervals, CVP was significantly lower in the off-pump group.

CONCLUSIONS

In patients with severe right coronary stenosis, off-pump cardiac surgery seemed to provide better right ventricular protection.

[Continuous infusion of remifentanil and target-controlled infusion of propofol for coronary surgery in elderly patients: comparison with continuous infusion of remifentanil and propofol]

OBJECTIVES

Comparison of the length of mechanical ventilation and postoperative complications after coronary surgery in elderly patients anaesthetised with propofol associated with either alfentanil or remifentanil.

STUDY DESIGN

Retrospective study with an historic control group.

PATIENTS

Three hundred thirty-eight consecutive patients (75-year-old or more) undergoing isolated coronary surgery. One hundred and fifty seven patients operated between January 1998 and June 2000 received alfentanil (1 microg/kg/minute) with a manually control infusion of propofol, 181 operated between July 2000 and 2002, remifentanil 0.25 microg/kg/minute with target controlled infusion of propofol (target blood concentration: 1.5 to 2 microg/ml).

METHODS

The two groups were compared for preoperative and surgical data. The length of mechanical ventilation, stay in ICU and the main postoperative complications were compared between the two groups.

RESULTS

Length of mechanical ventilation was significantly reduced in the remifentanil group (6 +/- 9 h vs. 13 +/- 63 h ; p <0.0001), 70% of the patients were extubated before the 6th postoperative hours against 53% in the alfentanil group (p =0.0023). This was not associated with a reduction of stay in ICU or postoperative complications. During surgery, an increased used of vasopressor was observed in the remifentanil group (40.2% vs 2.4% ; p <0.0001) with a postoperative elevation of blood concentration of CKMb (35.7 +/- 38.2 microg/l, vs. 27.7 +/- 31.9 microg/l, p =0.02).

CONCLUSION

Elderly patients undergoing coronary surgery were extubated earlier with remifentanil. However, this had no effect on duration of ICU stay but was associated with an increased used of vasopressor.

Propofol and sufentanil titration with the bispectral index to provide anesthesia for coronary artery surgery

BACKGROUND

To provide anesthesia for cardiac surgery, hypnotics and opioids are frequently titrated on variables such as mean arterial pressure and heart rate. In this study conducted in patients scheduled to undergo coronary artery bypass grafting, propofol and sufentanil, both administered by computer-controlled infusion, were titrated on the Bispectral Index (BIS) values using a predefined algorithm.

METHODS

After written informed consent, 110 patients, 95 men and 15 women aged 61 (9) yr [mean (SD)], were randomly allocated to receive predicted sufentanil effect site concentrations (Ce) of 0.5, 0.75, 1, 1.25, and 1.5 ng/ml, decreased by a third after sternotomy (groups 1-5). Target induction propofol concentration was 1.5 microg/ml and subsequently adjusted on BIS values. The following parameters were recorded: BIS values, predicted propofol Ce, the number of changes of propofol target, mean arterial pressure, heart rate, the number of bolus injection and doses of vasoconstrictor and vasodilator drugs, time to tracheal extubation, postoperative awareness and satisfaction scores, and cumulative morphine doses for the first postoperative day.

RESULTS

One patient randomized to group 1 required 0.75 ng/ml sufentanil Ce instead of 0.5 ng/ml for increased BIS values on tracheal intubation. BIS values were similar in the five groups. The predicted propofol Ce values were different (P < 0.05; analysis of variance) among the five groups: 1.59 (0.47) to 1.23 (0.25) microg/ml in group 1 and group 4, respectively. Significantly fewer changes of propofol target were required in group 4 as compared to group 1. There were no differences among the five groups for mean arterial pressure, heart rate, time to tracheal extubation, awareness, satisfaction scores, and morphine requirements.

CONCLUSION

These results suggest the BIS, as part of an algorithm that uses both the absolute BIS value and its increase following tracheal intubation, can be used to effectively titrate both propofol and sufentanil. A predicted sufentanil Ce of 1.25 ng/ml before and 0.8 ng/ml after sternotomy was associated with the lowest predicted propofol Ce and fewer changes of propofol target. Lower sufentanil concentrations required higher propofol concentrations and more frequent changes of the target propofol concentration and were associated with similar hemodynamic tolerance.

Inhaled nitric oxide: effects on hemodynamics, myocardial contractility, and regional blood flow in dogs with mechanically induced pulmonary artery hypertension

BACKGROUND

Pulmonary artery hypertension with right ventricular failure is a frequent complication that occurs immediately after heart transplantation in which the use of inhaled nitric oxide may be effective.

METHODS

The effects of pulmonary artery hypertension and nitric oxide on myocardial function and on pulmonary and systemic hemodynamic parameters were evaluated in eight anesthetized dogs. Pulmonary artery hypertension was induced by successive microbead injections into the pulmonary circulation.

RESULTS

Microbead injections resulted in overt pulmonary artery hypertension (pulmonary artery pressure, + 190%; pulmonary vascular resistance, + 389%; ratio of pulmonary vascular resistance to systemic vascular resistance, 0.41).

RESULTS

The end-diastolic length of the right ventricular outflow tract increased significantly along with an increase in right ventricular contractility (peak first derivative of left ventricular pressure as a function of time, + 100%; outflow tract systolic shortening, + 19%). Despite this compensatory mechanism, the increased pulmonary barrier resulted in a decrease in stroke volume (-31%). Systemic effects were observed, such as an increase in heart rate that maintained the cardiac output despite a decrease in left ventricular end-diastolic length (end-diastolic length in region of left anterior descending artery, - 9%). Right myocardial and septal blood flows were also significantly increased.

CONCLUSIONS

Nitric oxide administration restored the stroke volume with a decrease in pulmonary artery hypertension and an improvement of the pulmonary vascular resistance to systemic vascular resistance ratio. Systemic blood pressure and coronary perfusion remained unaffected. This selective effect on the pulmonary circulation should be considered a major advantage of nitric oxide inhalation in the treatment of right ventricular dysfunction in acute pulmonary hypertension.

[Prediction of respiratory complications after surgery of the abdominal aorta]

The most frequent type of complication in patients undergoing aortic surgery is respiratory. Preoperative lung function (PFT) and arterial blood gas measurement (ABG) are often carried out to assess the risk more precisely. The aim of the present retrospective study was to determine which value of lung function test could identify patients who developed such complications. "Receiver Operating Characteristic" (ROC) curves and the area beneath the curve for the diagnosis of respiratory complications were calculated for each variable of PFT and ABG. The greatest Youden index for each variable was chosen as indicative pulmonary function criterion of increased risk of pulmonary complications. One hundred and ninety-five patients (age: 65 +/- 10 years) were included. Respiratory complications occurred in 15% of patients. Respiratory complications increased from 12% if the vital capacity (VC) was > or = 77% of the predicted value to 35% if the VC was < 77% (P = 0.002), and from 10% if the FEV1 was > 76% to 34% if the FEV1 was > or = 76% (P = 0.0005). A decreased PaO2 or increased PaCO2 was not correlated with an increased incidence of respiratory complications. Length of stay in ICU or in hospital were increased when VC or FEV1 were low. Frequency of pulmonary complications was 9% in patients without PFT abnormalities, 16% in patients with either diminished VC or FEV1 and 35% in patients with both lowered VC and FEV1. However, all the areas under the ROC curves were < 0.7 and the sensitivity of the different variables was low. It is concluded that routine preoperative PFT and ABG cannot predict respiratory complications after abdominal aortic surgery.

[Consumption coagulopathies following peritoneojugular bypass. Prevention by a heparin-antithrombin III combination]

Consumption coagulopathy (CIVD) is a frequent complication of peritoneojugular bypass operation. Preventive treatment applied involves low-dose heparin (1.5 mg/kg/d) to maintain an antithrombin III concentration of at least 65%. Results are evaluated in 6 patients treated by 7 bypass operations. A biologic CIVD developed in 2 cases (29%) but no clinical coagulopathy was observed. This incidence is less than that usually reported, a literature review indicating a biologic coagulopathy in 65% of cases, with clinical evidence in 12.5%. Furthermore, patients with spontaneously elevated AT III levels did not develop CIVD while, in contrast, sufficiently high concentrations of AT III could not be maintained in the 2 patients with coagulopathy. These findings suggest the interest of prevention of a CIVD by the use of this procedure.

[Secondary rupture of the spleen after external cardiac massage]

A case of delayed splenic rupture occurring 18 days after external cardiac massage is reported. A 30 year old woman underwent mitral valve replacement. Two cardiac arrests in the immediate postoperative period were successfully treated by external cardiac massage. Recovery was uneventful until the 18th day, when the patient began to suffer from dizziness. Haemodynamic and biological data suggested hypovolaemia by dehydration. The day after, her abdomen became painful and anaemia was discovered. Splenic rupture was diagnosed by abdominal ultrasonography and splenectomy was carried out; no other lesion was found. In spite of the widespread practice of external cardiac massage, splenic rupture without any other lesion is unusual. It is suggested that abdominal ultrasonography should follow all cardiac massages.

[Fentanyl-oxygen-pancuronium anaesthesia in cardiac surgery (author's transl)]

A retrospective study of the anaesthetic records in cardiac surgical patients was undertaken: massive doses of fentanyl were used according to Stanley (29). The rate of drug administration was fentanyl 150 micrograms/kg for induction and 15 to 25 micrograms/kg/hour for maintenance, pancuronium bromide 0,1 mg/kg for induction and 0,015 mg/kg/hour for maintenance. Myocardial oxygen consumption (estimated by rate-pressure-product) during induction period remains constant. The oesophago-rectal temperature gradient is smaller than with other anaesthetic techniques, showing a very good perfusion homogeneity without the need of vasodilatator drugs. The temperature after-drop in the post bypass period is also reduced (less than 1,2 degrees C). The incidence of hemodynamic and rhythmic disturbances during operations and during the first post-operative day is lowered. Delayed respiratory autonomy appears to be the major drawback of this method (group 1: 25,30 h +/- 7,30 h; 30,20 h +/- 12,25 h; group 3: 21,15 h +/- 6,25 h).

24-hour Althesin-fentanyl anaesthesia in dogs. Time course of haemodynamic changes

A 24-h anaesthetic using a constant flow infusion of Althesin, fentanyl and pancuronium was given to 10 artificially ventilated dogs. No statistically significant haemodynamic changes occurred during the study, suggesting that the technique may be of value in long-term physiological studies.

24-hour extracorporeal membrane oxygenation in the hypoxic dog: hemodynamics and pulmonary gas exchange

Hemodynamic and pulmonary gas exchange values were investigated during 24-hour extracorporeal membrane oxygenation performed on 7 anesthetized dogs subjected to alveolar hypoxia. The chief effects of extracorporeal membrane oxygenation were demonstrated. The duration of the extracorporeal membrane oxygenation was associated with a progressive decline in the systemic arterial pressure and heart rate and a progressive increase in the pulmonary blood flow rate. Left-ventricular stroke work remained constant. The sum of the pulmonary and extracorporeal oxygen uptakes showed no change in spite of large variations in pulmonary flow rate.

[Critical study of the hemodynamic status during anesthesia]

Physicians must choose the anaesthetics for their patients and select the methods to cheek their haemodynamic status. Experimental works do not always bring sufficient information to help them in their daily practice. Circulatory reaction to a pharmacodynamic agent is diffuse and non-specific. Some examples drawn from theoretical considerations and practical situations support this view. The difficulty of assessing the actual damage caused by one apparent variation still remains. On the other hand, haemodynamic indices such as PA, CVP, dP/dt are composed of elementary data that are interdependent; so indices are interdependent, too. A puzzling fact is that depressing anaesthetics can initiate severe haemodynamic crisis, generally badly tolerated by tissues, but better tolerated by myocardium which is not definietely altered if the anoxia inflicted is accompanied by a real decrease in cardiac work. This explains the often slight effect of short anesthetic overdosage. Previous haemodynamic variations to be countered relative to anaesthesia are not really known. Biochemistry of the venous coronary blood does not yet bring striking features in this field.