[Anaesthesia and prostate surgery]. / Anesthésie et chirurgie de la prostate.

OBJECTIVES: To review the current data about anaesthetic management in prostate surgery with special regards on analysis and prevention of specific risks, appropriate anaesthetic procedure keeping with surgery and patient, recognition and treatment of adverse events. DATA SOURCES AND EXTRACTION: The Pubmed database was searched for articles (1990-2004) combined with references analysis of major articles on the field. DATA SYNTHESIS: It is strongly recommended to settle germfree urine in the preoperative period. The thromboembolic risk of radical retropubic prostatectomy for cancer parallels lower abdomen oncologic surgery and is prolonged. Preoperative evaluation of cardiovascular, respiratory, neurological and metabolic comorbidity is a source of prognostic information and an essential tool in the management of elderly patients with prostate disease. Extreme patient positioning applied in prostate surgery induces haemodynamic and respiratory changes and are associated with severe muscular and nervous injuries. The laparoscopic access for radical prostatectomy is a growing alternative to the open surgical procedure. Acute normovolaemic haemodilution is a consistent and cost-effective blood conservation strategy in reducing allogenic blood transfusion for radical retropubic prostatectomy. Whether open transvesical or transurethral prostatectomy for treatment of benign hypertrophy depends on the size of the gland: transurethral resection is safe up to 80 g. Intrathecal anaesthesia with a T9 cephalad spread of sensory block, produces adequate conditions for transurethral prostatectomy and allows a rapid diagnosis of irrigating fluid absorption syndrome. In spite of recommended preoperative antibiotic prophylaxis, bacteriemias are frequent during transurethral prostate resection.

[Evaluation of the cardiac risks in non-cardiac surgery in patients with heart failure]. / Evaluation du risque cardiaque en chirurgie non cardiaque chez l'insuffisant cardiaque.

Cardiac insufficiency represents a major risk factor in patients about to undergo non-cardiac surgery. The post-operative mortality is linked to the severity of the pre-operative functional impairment: rising from 4% in NYHA class 1 to 67% in class IV. The operative risk is greater when the cardiac insufficiency is more disabling, the patient is older (> 70 years) and if there is a history of acute pulmonary oedema and a gallop bruit on auscultation. The use of metabolic equivalents (Duke Activity Status Index) is recommended: the functional capacity is defined as excellent if > 7 MET, moderate between 4 and 7, or poor if < 4. A non-invasive evaluation of left ventricular function is necessary in each patient with obvious congestive cardiac insufficiency or poor control under the American consensus, but it is rare that the patient has not already been seen by a cardiologist. The degree of per-operative haemodynamic constraint is linked to the surgical technique and is stratified according to the type of surgical intervention and whether or not it is performed as an emergency. An intervention duration > 5 hours is associated with an increased peri-operative risk of congestive cardiac insufficiency and non-cardiac death. Deaths from a cardiac cause are thus twice as frequent after intra-abdominal, non-cardiac thoracic or aortic surgery and the post-operative cardiac complications are six times more frequent. Numerous studies have attempted to document the impact of different anaesthetic techniques on the prognosis for the population at increased risk of post-operative cardiovascular complications. It is advisable to opt for peripheral nerve blocks. The cardiovascular morbidity and overall mortality do not differ between general anaesthetic, epidural anaesthetic or spinal nerve block. The ASA (American Society of Anesthesiologists) classification is widely used to determine the overall risk. The ASA class and the age are however too coarse as methods of evaluation for the individual risk and for giving judicious pre-operative advice. Multifactorial cardiac risk indexes such as that of Goldman allow overall evaluation (taking the patient and the intervention into account) of the peri-operative cardiovascular risk in non-cardiac surgery as a function of predictive clinical elements. Nine variables concerning the patient's history, the physical examination and several simple supplementary examinations are identified for which the relative weight is recorded under a points system. The average risk score for a given procedure is converted into an average risk for a given patient using a nomogram such as Detsky's. Surgical acts which do not impose major constraints on the cardiocirculatory apparatus (ophthalmic surgery for example) do not require supplementary examinations. The risk of post-operative cardiac complications is low in the absence of the 9 risk factors defined by Goldman, as is an ischaemic syndrome (angina on light physical activity, unstable angina, myocardial infarction). Certain risk factors (jugular congestion, gallop bruit, recent myocardial infarction, non-sinus rhythm, extrasystoles, aortic stenosis) obviously require appropriate treatment beforehand. The sometimes difficult process demands a dialogue between the cardiologist and the surgeon, the recognition of the risk of surgery in a given centre, and the opinion of the patient duly informed of the terms of the discussion about him.

[Discitis after spinal anesthesia for transurethral resection of the prostate]. / Spondylodiscite après rachianesthésie pour résection transurétrale de prostate.

We described a case of discitis and meningitis following spinal anaesthesia for transurethral resection of the prostate. The patient received antibiotics for a month before surgery, because of Klebsiella prostatitis. Spinal anaesthesia was performed in L3-L4 interspace by using 22G Quincke needle. Bacteriaemia occurred during the first postoperative hours. Ten days after spinal anaesthesia, patient suffered from lumbar pain, exacerbated by vertebral percussion, and motor weakness within lower limb, which was marked on right side. MRI examination showed L3-L4 discitis with psoas abcess in regard, and epiduritis marked around L3 right spinal root. CSF examination confirmed meningitis but no bacteria was found. Antibiotics were administered over a 6 weeks period, and then patient discharged from hospital without neurological sequellae. Infectious discitis related to disk puncture during spinal anaesthesia and postoperative bacteriaemia was likely in our patient.

Postoperative epidural analgesia with bupivacaine and fentanyl: hourly pain assessment in 348 paediatric cases.

BACKGROUND: The objective of this prospective study was the evaluation of the analgesia provided by an epidural infusion of bupivacaine and fentanyl after different types of surgery in children. METHODS: Data were collected from 348 epidural analgesia in 87 children below 2 years of age, in 80 children between 2 and 6 years and 181 above 6 years of age, for a median duration of 43 postoperative hours. Bupivacaine (mean concentration 0.185%) and fentanyl (5 microg.kg-1.day-1) were administered on the surgical ward. RESULTS: Pain control was considered excellent in 86% of the 11 072 pain hourly assessments. Analgesia was found to be better for children older than 2 years, and the overall quality of their night's sleep was better than that of older children. Higher pain scores were noted for Nissen fundoplication surgery and club foot repairs. Early discontinuation rarely occurred, and only because of technical problems with the epidural catheter (4%) or insufficient analgesia (6%). Complications were minor (nausea/vomiting 14%, pruritus 0.6%, urinary retention 17%) and easily reversed. CONCLUSIONS: This combination of bupivacaine-fentanyl provides safe analgesia after major surgery in children with frequent clinical monitoring. Regular pain assessments of intensity and duration are useful to improve the quality of postoperative analgesia.

Intrathecal anesthesia: ropivacaine versus bupivacaine.

We compared intrathecal ropivacaine to bupivacaine in patients scheduled for transurethral resection of bladder or prostate. Doses of ropivacaine and bupivacaine were chosen according to a 3:2 ratio found to be equipotent in orthopedic surgery. One hundred patients were randomly assigned to blindly receive either 10 mg of isobaric bupivacaine (0.2%, n = 50) or 15 mg of isobaric ropivacaine (0.3%, n = 50) over 30 s through a 27-gauge Quincke needle at the L2-3 level in the sitting position. Onset and offset times for sensory and motor blockades and mean arterial blood pressure were recorded. Pain at surgical site requiring supplemental analgesics was recorded. Cephalad spread of sensory blocks was higher with bupivacaine (median level, cold T(4) and pinprick T(7)) than with ropivacaine (cold T(6) and pinprick T(9)) (P<0.001). Eight patients in Group Ropivacaine received IV alfentanil (P<0.01). Onset time (mean +/- SD) to T(10) anesthesia and offset time at L2 were not different (bupivacaine = 13 +/-8 min, 127+/-41 min; ropivacaine = 11+/-7 min, 105+/-29 min). Complete motor blockade occurred in 43 patients with bupivacaine and in 41 patients with ropivacaine (not significant). Total duration of motor blockade was not different. No difference in hemodynamic effects was detected between groups. No patient reported back pain. We conclude that 15 mg of intrathecal ropivacaine provided similar motor and hemodynamic effects but less potent anesthesia than 10 mg of bupivacaine for endoscopic urological surgery.

The efficacy of intravenous 0.15 versus 0.25 mg/kg intraoperative morphine for immediate postoperative analgesia after remifentanil-based anesthesia for major surgery.

UNLABELLED: We evaluated the effect of perioperative administration of two doses of morphine for postoperative analgesia after remifentanil-based anesthesia. The prospective, randomized study included 245 patients from 33 centers. All patients were scheduled for abdominal or urological surgery lasting more than 1 h. General anesthesia used remifentanil as the perioperative opioid (1 microg/kg as a bolus then, 0.5 microg/kg as a continuous infusion). A morphine bolus of 0. 15 mg/kg (0.15-mg group) or 0.25 mg/kg (0.25-mg group) was administered 30 min before the end of surgery. In the postanesthesia care unit, pain scores for patients were evaluated by using behavioral pain scores of 1-3, verbal pain scores of 0-3, and visual analog scale scores of 0-10). Postoperative analgesia was obtained by a morphine titration (3 mg every 5 min). Demographic and surgery characteristics were similar in both groups. The delay for first demand of morphine was similar in the 0.15-mg and the 0.25-mg groups (26 [9-60] and 30 [10-60] min, respectively). The frequency of morphine titration was similar in both groups (75% and 66%, respectively). The amount of morphine used in the postanesthesia care unit was smaller in the 0.25-mg group (0.16 [0.0-1.25] vs 0.10 [0.0-0.56] mg/kg; P = 0.008). In the 0.25-mg group, the behavioral pain score was lower at 15 min, the verbal pain score was lower at 60 min (P < 0.001), and similar at 30 min. The visual analog scale pain score at 30 min and 60 min was similar in both groups. The incidence of minor side effects was similar in both groups. However, three cases of postoperative respiratory depression occurred in the 0.25-mg group compared with no cases in the 0.15-mg group. In conclusion, perioperative administration of morphine alone does not provide entirely adequate immediate postoperative pain control after remifentanil-based anesthesia in major surgery. IMPLICATIONS: The administration of 0.15 or 0.25 mg/kg perioperative morphine during remifentanil-based anesthesia for major surgery does not preclude additional morphine administration in the postanesthesia care unit. The larger dose of 0.25 mg/kg slightly improves postoperative analgesia; however, it may be responsible for postoperative respiratory depression.

[Sciatic nerve block: an new lateral mediofemoral approach. The value of its combination with a "3 in 1" block for invasive surgery of the knee]. / Bloc du nerf sciatique: une nouvelle voie d'abord latérale médiofémoral. Intérêt de son association à un bloc "3 en 1" pour la chirurgie invasive du genou.

OBJECTIVE: To describe a new midfemoral lateral approach for the sciatic nerve block. Its combination with the "3 in 1" block was tested for postoperative analgesia following major surgery of the knee. STUDY DESIGN: Descriptive, anatomical and clinical study prospective. PATIENTS: After testing in four unembalmed corpses the new approach was applied to 42 ASA 1-2 patients, in combination with a continuous "3 in 1" block. METHODS: The new approach was analysed for reliability of the surface landmarks (a line drawn from the posterior margin of the greater trochanter towards the knee and parallel to the femur) and block extent assessed on the foot. Its combination with the "3 in 1" block was evaluated with a visual analogue scale (VAS) scoring, for postoperative analgesia after total knee arthroplasty. RESULTS: The sciatic nerve was located in less than 10 min. A block of the sciatic nerve was fully achieved in all patients. Its median duration was 16 h. The median VAS score at rest was 0 mm (sciatic bloc + continuous block "3 in 1"), but increased to 40 mm (block "3 in 1" alone). CONCLUSION: The new lateral midfemoral sciatic block is easy to master. Combined with a continuous "3 in 1" block, it provides excellent analgesia during the early postoperative period after major surgery of the knee.

Intrathecal bupivacaine in humans: influence of volume and baricity of solutions.

BACKGROUND: The effects of volume and baricity of spinal bupivacaine on block onset, height, duration, and hemodynamics were studied. METHODS: Ninety patients undergoing endoscopic urologic procedures were randomized to receive 10 mg of intrathecal bupivacaine at L2-L3 level in sitting position. In the operating room, commercial products were diluted as needed with NaCl 0.9% to obtain isobaric solutions (density, 1.005-1.008) or with NaC 10.9% and glucose 30% to obtain hyperbaric solutions (density, 1.031-1.037) of 2, 5, or 10 ml (six groups of 15 patients each). Three minutes after spinal injection the patients were placed in lithotomy position. Sensory blockade was assessed using pinprick and cold sensation tests, and motor blockade was assessed using a four-point scale. RESULTS: Onset times to maximal cephalad spread of spinal blockade were similar with isobaric and hyperbaric solutions. A greater maximal cephalad spread of anesthesia was obtained with diluted isobaric bupivacaine but was not associated with more hypotension. Volume had no effect on cephalad extent of anesthesia with hyperbaric bupivacaine. Times for regression of anesthesia to L2 and offset of motor block were longer with isobaric than with hyperbaric solutions of bupivacaine. The intensity of motor blockade was decreased with diluted hyperbaric bupivacaine. No patient reported back pain. CONCLUSION: In this study, volume had no significant influence on either cephalad spread or duration of sensory blockade for either isobaric or hyperbaric bupivacaine. Time for offset of anesthesia was shorter with hyperbaric bupivacaine compared with isobaric solutions.

[Postoperative antero-external tibial compartment syndrome: co-responsibility of the operating table]. / Syndrome postopératoire des loges tibiales antéro-externes: coresponsabilité de la table opératoire.

A 26-year-old, ASA1 patient underwent maxillofacial surgery under general anaesthesia, of 12-hour duration in the supine position. Postoperatively he developed rhabdomyolysis and acute renal failure. In the subsequent days, a bilateral leg compartment syndrome occurred with anterior tibial motor nerve injury requiring fasciotomies and excision of necrotic muscles. Several aetiological factors may have contributed to this accident: a long-lasting procedure, controlled hypotension and inappropriate position of the lower limbs. A laboratory study showed that the hardness of some new operating tables could be responsible for this complication. Some prophylactic measures are therefore required before the use of such devices.

The urodynamic effects of intravenous opioids and ketoprofen in humans.

UNLABELLED: We used a double-blind design to study urodynamic changes induced by mu-agonists (fentanyl, morphine), a partial mu-agonist antagonist (buprenorphine), a putative mu-antagonist, kappa-agonist (nalbuphine), and ketoprofen, an injectable nonsteroidal antiinflammatory drug. Men (20-55 yr old) were randomly assigned to receive one of the following i.v. before anesthesia for endoscopic extraction of a ureteral stone: 10 mg of morphine, 0.3 mg of buprenorphine, 0.35 mg of fentanyl, 20 mg of nalbuphine, 100 mg of ketoprofen, or 10 mL of 0.9% sodium chloride. The urodynamic study consisted of cystometry followed by urethral pressure profile. Measurements were taken before the i.v. infusion of drugs and 15 min thereafter. Statistical comparisons were performed by using analysis of variance with repeated measurements (P < 0.05). Ketoprofen and saline did not induce any urodynamic changes. Opioids altered bladder sensations, and the residual volume after voiding increased, except after morphine. Detrusor contraction decreased only after the administration of fentanyl and buprenorphine. Some patients could not micturate after receiving morphine, fentanyl, and buprenorphine. Compliance and urethral pressures did not change with any drug. This study suggests that ketoprofen and nalbuphine are useful analgesics in terms of their urodynamics. IMPLICATIONS: We compared the urodynamic effects of opioids and ketoprofen used as analgesics in surgical patients. In contrast to ketoprofen, opioids altered urodynamics. The opioid nalbuphine had no effect on detrusor contraction. This study suggests that ketoprofen and nalbuphine are useful analgesics in terms of their urodynamics.

[Preoperative evaluation of coronary circulation]. / Evaluation préopératoire de la circulation coronaire.

It is not easy to define a plan for the preoperative assessment of the coronary circulation: some studies carried out in the context of vascular surgery are contradictory and no method has a sensitivity and specificity of 100%. Nevertheless, it is essential to select patients with a high risk of perioperative cardiac complications so that their medical treatment can be reinforced or anatomical correction envisaged. A first assessment is obtained from the history, the clinical examination and simple investigations (resting ECG, chest X-ray). Surgical operations which do not impose a major strain on the cardiovascular system do not require further investigations. The risk of postoperative cardiac complications is low in the absence of the nine risk factors defined by Goldman and/or an ischemic syndrome (residual angina after mild physical activity, unstable angina, myocardial infarct). The problem arises in patients with the Goldman risk factors and/or a history of coronary insufficiency and/or coronary insufficiency risk factors (diabetes, tobacco, hypercholesterolemia, age > 70 years, arterial hypertension), who require an operation likely to cause a particularly serious strain on the cardiovascular system. An exercise ECG, by the Holter method, is helpful, particularly in known or potential coronary arteriopaths who cannot exercise. Echocardiography under dobutamine has good sensitivity and good specificity when exercise is impossible. Thallium-dipyridamole scanning has not been shown to be helpful in vascular surgery. This method could be refined by a quantitative analysis of the number of areas and segments involved. Finally, patients showing ischaemic changes on continuous ECG recording, abnormalities on echocardiography under dobutamine, abnormalities on thallium-dipyridamole myocardial scanning or on exercise ECG, should be considered for coronary angiography with a view to a preliminary anatomical correction.

A novel supraclavicular approach to brachial plexus block.

We describe a novel supraclavicular approach to the brachial plexus. Designated as the intersternocleidomastoid technique, this new approach was tested in unembalmed cadavers. It was then applied for evaluation to 150 ASA grade I or II patients scheduled for elective surgery or physiotherapy of the upper limb or for treatment of reflex sympathetic dystrophy associated with painful shoulder. The new approach was easy to master because of a very simple surface landmark, i.e., the triangle formed by the sternocleidomastoid heads, which were visible and palpable in most patients studied (90%). The procedure was effective intraoperatively, providing satisfactory anesthesia in 140 patients (93%), partially satisfactory blocks in 6 (4%), and unsatisfactory blocks in only 4 (3%). The catheter entry point is cephalad enough not to obscure the surgical field on the shoulder. Catheter insertion was successful in 63 of 70 patients. Postoperative analgesia was provided for 48 h or more in 45 patients and for 24 h in 18 patients. Only minor complications were observed: asymptomatic phrenic nerve block in 89 patients (60%), transient Horner's syndrome in 15 (10%), transient recurrent laryngeal nerve blockade in 2, and misplacement of the catheter into the subclavian vein in 1 patient. No pneumothorax was observed.

Pharmacodynamic dose-response and safety study of cisatracurium (51W89) in adult surgical patients during N2O-O2-opioid anesthesia.

After administration of doses ranging from 0.025 to 0.25 mg/kg, the neuromuscular blocking effect of cisatracurium was assessed in 119 adult surgical patients receiving N2O-opioid-midazolam-thiopental anesthesia. The calculated 95% effective dose (ED95) for inhibition of adductor pollicis twitch evoked at 0.1 Hz was 0.053 mg/kg. With 0.10 mg/kg injected over 5-10 and 20-30 s, median onset times (range) were 5.8 (3.0-7.7) and 4.8 (1.2-10.2) min, respectively, and median times to 5% and 95% recovery (range) were 27 (19-46) and 48 (25-68) min, respectively. For doses of 0.10, 0.20, and 0.25 mg/kg, median 5%-95% and 25%-75% recovery indexes ranged from 48 to 90 min and 8 to 9 min, respectively. After administration of neostigmine (0.06 mg/kg) at 10%-15% or 16%-30% recovery, the median times to 95% recovery (range) were 6 (2-22) and 4 (2-5) min, respectively. There were no changes in heart rate, blood pressure, or plasma histamine concentrations during the first 5 min after administration of cisatracurium at doses up to 5 x ED95 injected over 5-10 s. No cutaneous flushing or bronchospasm was noted. In summary, cisatracurium is a potent neuromuscular blocking drug with an intermediate duration of action, characterized by excellent cardiovascular stability, with no apparent histamine release.

[Preoperative evaluation of coronary circulation]. / Evaluation préopératoire de la circulation coronarienne.

To define a strategy for coronary circulation assessment is a difficult task as most of the studies have been carried out in vascular surgery, as some of them are controversial, and as no test has a 100% sensitivity and specificity. However patients with high perioperative risk of cardiac events have to be identified, in order to intensify medical treatment or to consider myocardial revascularisation. A first evaluation is based on history, physical examination and simple tests, such as rest electrocardiogram and thorax X-Ray. Additional tests are not required when surgery does not elicit a major activity of the cardiocirculatory system. Postoperative cardiac risk is low when none of the nine risk factors defined by Goldman and/or coronary insufficiency (residual angina elicited by minor physical activity, unstable angina, myocardial infarction) are present. The problem remains in patients with Goldman risk factors and/or at risk of coronary artery disease because of diabetes mellitus, heavy smoking, hypercholesterolaemia, arterial hypertension, undergoing major abdominal, thoracic or vascular surgery. Preoperative electrocardiographic Holter monitoring is still of value, especially in patients with known or supposed ischaemic heart disease and unable to make a physical effort. A poor exercise capacity and changes in electrocardiographic stress testing are factors of poor prognosis. The dobutamine stress echocardiography has a good sensitivity and specificity when an effort test cannot be performed. The value of dipyridamole-thallium 201 scintigraphy could be improved by a quantitative analysis of the number of affected segments and territories. Patients with angina or ischaemic episodes on continuous electrocardiogram, or with dobutamine echocardiography kinetic disturbances and with stress myocardic scintigraphy or stress exercise testing abnormalities could undergo a coronarography, in order to consider myocardic revascularization prior to surgery.

Comparison between oxygen consumption calculated by Fick's principle using a continuous thermodilution technique and measured by indirect calorimetry.

We calculated oxygen consumption by the reverse Fick principle (cVO2) using cardiac output measured with a new technique of continuous thermal dilution and compared these values with measurements made at the same time using a gas exchange method (mVO2). We studied nine patients in a stable condition after cardiac surgery. In each patient six successive measurements of continuous cardiac output and mVO2 were made over 5 min at 10-min intervals. The mean difference between the estimates (mVO2-cVO2) was 15 ml min-1 m2 (95% confidence limits, -3 to 33 ml min-1 m2). The relative error of each method was 5% and 4% (continuous cardiac output and gas exchange methods, respectively). Calculation of VO2 using the new cardiac output technology had good repeatability compared with direct measurement, probably because of the high precision of measurement of cardiac output.

A new axillary approach for continuous brachial plexus block. A clinical and anatomic study.

Catheter insertion in the neurovascular space by axillary approach allows a continuous brachial plexus block and/or postoperative analgesia. We developed a perivenous technique whereby the approach to the neurovascular sheath is guided under fluoroscopy by a preopacified axillary vein. A randomized study compared this technique to the technique of Selander in ASA grade I-II patients scheduled for surgery or painful physiotherapy of the hand. The study was performed in 36 patients randomly divided into two groups. In Group 1 (n = 18), the catheter was placed according to the technique described by Selander. In Group 2 (n = 18), the catheter was placed using our perivenous technique. A complete block was obtained in all the patients of Group 2 vs only 50% of the patients in Group 1 (P < 0.05). In Group 1 a partial block was observed in 17%, with failure in 33% of the patients. There was no difference in the two groups regarding the time required to perform either technique, the duration of the complete block, the pain score, or the amount of continuously administrated bupivacaine during the first 48 h postoperatively. The plasma concentrations of total bupivacaine (high-performance liquid chromatography) were low in successful blocks, with no differences in the two groups; the median value was 0.68 microgram/mL (95% confidence interval: 0.62-0.89). The concentrations were higher (P < 0.01) in failed blocks; the median value was 1.69 micrograms/mL (95% confidence interval: 0.58-2.8). A complementary anatomic study of three arms from fresh cadavers allowed verification of the correct localization of the Teflon cannula and flexible catheter, as well as homogeneous diffusion of the methylene blue inside the brachial plexus. The perivenous technique for continuous axillary brachial plexus block may improve the success rate due to its radiologic and accurate location of the neurovascular sheath.

[Comparison of cardiac output measured continuously by thermodilution and calculated according to Fick's principle]. / Comparaison du débit cardiaque mesuré en continu par thermodilution et celui calculé selon le principe de Fick.

Recently, a thermodilution technique for continuous measurement of cardiac output was introduced. The aim of this study was to evaluate the accuracy of continuous cardiac output measurement using the thermodilution technique (CCO) and to assess the correspondence between CCO and cardiac output obtained with the Fick's principle (Fick-CO). Nine patients were studied in the postoperative period after cardiac surgery. A new pulmonary artery catheter modified by attachment of a thermal filament (Intellicath, Model PA3-H-8Fr) was inserted and connected to a continuous cardiac output computer (Vigilance Monitor). Oxygen consumption was continuously measured using the gas exchange method (Deltatrac Metabolic Monitor). Fick-CO was calculated according to the Fick's principle. The study in each patient consisted of 6 serial determinations of both CCO and Fick-CO at 10 min intervals. For 54 pairs of measurements, the mean difference (Fick-CO-CCO) was 0,6 L.min-1. The limits of agreement were--0,6 to 1,8 L.min-1 respectively. The relative error was 6% for CCO and 10% for Fick-CO. It is concluded that CCO and Fick-CO cannot be considered as being interchangeable. However, the accuracy of CCO is acceptable. The technique does not require any user calibration and eliminates the need of bolus injections. Further studies are necessary to determine the benefits of this new technique in the various clinical situations.