[Acute rhabdomyolysis after spinal anesthesia for knee arthroscopy]

We report an observation of acute rhabdomyolysis of gluteus maximum muscles occurring in a non-obese patient installed in supine position that underwent knee arthroscopy under spinal anaesthesia. The patient had insulin-dependent diabetes melitus with documented microangiopathy. The interest of this observation resides in the occurrence of the syndrome after a short period of time (one hour) of installation in the supine position in a patient that did not have any of the generally described risk factors of rhabdomyolysis.

EEG bispectral index and hypnotic component of anaesthesia induced by sevoflurane: comparison between children and adults

This prospective study was designed to evaluate the correlation between the electroencephalographic bispectral index (BIS) and the hypnotic component of anaesthesia (CA) induced by sevoflurane in 27 children and 27 adult patients. BIS and CA were compared at loss of consciousness (LOC) and on recovery of consciousness (ROC). Mean (SD) BIS decreased significantly at LOC in children and adults from 94 (2.7) to 87.4 (4) and from 96.2 (2) to 86.7 (4.4), respectively, without any difference between groups. Correlation coefficients (p) between BIS and CA at LOC were -0.761 in children and -0.911 in adults. BIS increased significantly at ROC in children and adults from 74.1 (4.2) to 86.7 (2) and from 80.2 (5) to 90.7 (3), respectively, without any difference between groups. Correlation coefficients between BIS and CA in ROC were -0.876 in children and -0.837 in adults. BIS values at ROC were not different from those at LOC in either group. These data demonstrate that BIS correlates with the hypnotic component of anaesthesia induced by sevoflurane in children as well as in adults.

Remifentanil and controlled hypotension; comparison with nitroprusside or esmolol during tympanoplasty

PURPOSE

To determine whether remifentanil, combined with propofol, could induce controlled hypotension, reduce middle ear blood flow (MEBF) measured by laser-Doppler flowmetry, provide a "dry" operative field, and could be compared with nitroprusside or esmolol combined with alfentanil and propofol.

METHODS

Thirty patients undergoing tympanoplasty and anesthetized with 2.5 mg x kg(-1) propofol iv followed by a constant infusion of 120 microg x kg(-1) x min(-1), were randomly assigned in three groups to receive either 1 microg x kg(-1) remifentanil iv followed by a continuous infusion of 0.25 to 0.50 microg x kg(-1) x min(-1), or nitroprusside iv, or esmolol iv combined for the latter two groups with alfentanil iv.

RESULTS

Controlled hypotension was achieved at the target pressure of 80 mmHg within 107 +/- 16, 69 +/- 4.4, 53.3 +/- 4.4 sec for remifentanil, nitroprusside and esmolol respectively. MEBF decreased by 24 +/- 0.3, 22 +/- 3.3, 37 +/- 3% and preceded the decrease in SABP, within 30 +/- 6.1, 11.2 +/- 3.1, 15 +/- 2.8 sec for remifentanil, nitroprusside and esmolol respectively. Remifentanil, and nitroprusside decreased MEBF autoregulation less than esmolol (0.36 +/- 0.1, 0.19 +/- 0.2, -0.5 +/- 0.2). Controlled hypotension was sustained in all three groups throughout surgery, and the surgical field rating decreased in a range of 80% in all three groups. Nitroprusside decreased pH and increased PaCO2. There were no postoperative complications in any of the groups.

CONCLUSIONS

Remifentanil combined with propofol enabled controlled hypotension, reduced middle ear blood flow and provided good surgical conditions for tympanoplasty with no need for additional use of a potent hypotensive agent.

[Can one use probabilistic protocols for antibiotic therapy in intensive care units?]

Due to a large spectrum, empiric antibiotics treatments participate to the increase in bacterial resistance. In order to improve its indications, the implementation of therapeutic guidelines in an ICU was studied. Empiric therapy was administered in 30% of the 178 patients receiving antimicrobial agents. Large spectrum drugs were prescribed in 26% of empiric treatments. The mean duration of empiric antibiotics administration was 3.2 days. It was concluded that it was possible to use guidelines of empiric antibiotic in an intensive care unit.

Respiratory mechanics during laparoscopic cholecystectomy: the effects of the abdominal wall lift

The abdominal wall lift (AWL) has been proposed for laparoscopic cholecystectomy to reduce hemodynamic effects caused by carbon dioxide (CO2) and high intraabdominal pressures (IAP). Data concerning effects of AWL on respiratory mechanics are scant. We therefore used a noninvasive method to evaluate whether the AWL could offset these effects. The PETCO2, airflow, and airway pressure were continuously measured in nine patients undergoing laparoscopic cholecystectomy using an AWL with minimal CO2 insufflation. We used a least-squares method to calculate maximal airway pressure (Pmax), elastance (Ers), and resistances (Rrs) of the respiratory system. After CO2 insufflation, the initiation of AWL resulted in a significantly decreased IAP (from 13 to 6 mm Hg; P < 0.001) and Rrs (from 20.6 to 17.8 cm H2O.L(-1).s(-1); P = 0.029), whereas Ers was partly modified (34.0 to 33.3 cm H2O/L; not significantly different). With AWL, we hypothesized that the diaphragm remained flat and stiff, outweighing the beneficial effect of the decrease of IAP on Ers. PETCO2 significantly increased after AWL and at the end of the procedure. We conclude that AWL partly reverses the impairment of the respiratory mechanics induced by CO2 insufflation during laparoscopic surgery.

IMPLICATIONS

The abdominal wall lift (AWL), acting on the abdominal chest wall, had some benefits during laparoscopic surgery by limiting CO2 peritoneal insufflation and several side effects, such as hemodynamics. We examined the consequences of this technique on respiratory mechanics in nine patients undergoing laparoscopic cholecystectomy. Our findings suggest that the AWL decreases intraabdominal pressure and respiratory resistances without a significant effect on respiratory elastance.

Autoregulation of human inner ear blood flow during middle ear surgery with propofol or isoflurane anesthesia during controlled hypotension

We used controlled hypotension to obtain a bloodless cavity during middle ear surgery under an optical microscope. No previous study has assessed the effect of controlled hypotension on inner ear blood flow (IEF) autoregulation in humans receiving propofol or isoflurane anesthesia. In the present study, the IEF autoregulation was determined using laser Doppler flowmetry in combination with transient evoked otoacoustic emissions (TEOAEs) during controlled hypotension with sodium nitroprusside in 20 patients randomly anesthetized with propofol or isoflurane. A coefficient of IEF autoregulation (Ga) was determined during controlled hypotension, with a Ga value ranging between 0 (no autoregulation) and 1 (perfect autoregulation). During controlled hypotension with propofol, IEF remained stable (1%+/-6%; P > 0.05) but decreased by 25%+/-8% with isoflurane (P < 0.05). The Ga was higher during propofol anesthesia (0.62+/-0.03) than during isoflurane anesthesia (0.22+/-0.03; P < 0.0001). Under propofol anesthesia, there were individual relationships between TEOAE amplitude and change in IEF in four patients. Such a correlation was not observed under isoflurane anesthesia. These results suggest that human IEF is autoregulated in response to decreased systemic pressure. Furthermore, isoflurane has a greater propensity to decrease cochlear autoregulation and function than propofol.

IMPLICATIONS

The present study shows that inner ear blood flow is autoregulated under propofol, but not isoflurane, anesthesia during controlled hypotension in humans during middle ear surgery. Further studies are needed to explore the postoperative auditory functional consequences of the choice of the anesthetic drug used in middle ear surgery.

Effect of anesthesia on transient evoked otoacoustic emissions in humans: a comparison between propofol and isoflurane

The influence of general anesthesia (GA) on auditory brainstem responses (ABRs) has been widely studied in humans whereas few studies have been devoted as yet to its effect on cochlear micromechanical properties. This study was aimed at evaluating: (1) the effect of GA on transient evoked otoacoustic emissions (TEOAEs) in humans (n=10), and (2) to compare the effects induced by two different anesthetic agents: propofol (n=5) and isoflurane (n=5). The TEOAEs were continuously monitored together with hemodynamic patterns describing various measures of blood pressure. (1) The GA induced a decrease in TEOAE amplitude and TEOAE amplitude was significantly correlated with the hemodynamic patterns. (2) Both anesthetic agents were responsible for a decrease in TEOAE during the first 20 min of recording. Under propofol, TEOAE amplitude increased after 20 min whereas under isoflurane TEOAEs continued to decrease. Under propofol, TEOAE amplitude was correlated with blood pressure changes in a highly significant manner, whereas under isoflurane TEOAE levels were completely independent of such hemodynamic patterns. These results infer that (1) the GA induced a decrease in TEOAE amplitude, and that (2) TEOAE changes induced by propofol could depend on the concomitant hemodynamic changes whereas isoflurane could be responsible for TEOAE changes depending on both, hemodynamic changes and its own pharmacological properties.

Sympathetic nerve regulation of cochlear blood flow during increases in blood pressure in humans

The purpose of this work was to show that regulation of the blood flow to the cochlea by the sympathetic nervous system occurs in humans at the level of the cochlear microcirculation during increases in blood pressure and that its involvement depends on the pressure level. Eight anaesthetized patients undergoing tympanoplasty for hearing disease took part in a pharmacological protocol of stimulation and inhibition of the autonomic nervous system (ANS) to provide variations in systolic blood pressure (BPS) and cochlear blood flow (CBF). The CBF was measured by laser-Doppler flowmetry. Changes in autonomic nerve activity were brought about by changes in baroreceptor activity (BR) initiated by the injection of an alpha adrenergic agent before and after sympathetic and parasympathetic blockade. The CBF variations (delta CBF) were plotted against BPS increases at each stage of the ANS inhibition. The BR diminished significantly after alpha blockade, after alpha and beta blockade, and after alpha and beta blockade and atropine, by 50% (P < 0.01), 29% (P < 0.05), and 95% (P < 0.001) respectively. The BPS increased significantly (P < 0.01) by 36 (SD 9)%, 47 (SD 1)%, and 67 (SD 16)% respectively. The CBF response to an increase in BPS exhibited two opposing variations in the patients: CBF decreased significantly in one group, and increased significantly in the other group. In both groups, delta CBF decrease and delta CBF increase, respectively, were significant after ANS blockade; even so the decrease and increase, respectively, levelled off at BPS around 160 mmHg before ANS blockade. For BPS below 160 mmHg, correlations between delta CBF and BPS were significant before inhibition and after inhibition of ANS. For BPS below 160 mmHg, BPS and delta CBF were not correlated before inhibition of ANS, and were significantly correlated after inhibition of ANS. For BPS below 160 mmHg, CBF response to the BPS increase was the same before and after ANS blockade, i.e. ANS control did not predominate: even so, for BPS above 160 mmHg, the CBF response to BPS increase was different before and after ANS blockade: CBF varied significantly after ANS blockade as it varied for BPS below 160 mmHg, while it remained constant before ANS blockade that elicited ANS control of CBF. In conclusion, sympathetic nerve regulation via its vasomotor tone at the level of cochlear microcirculation occurred markedly when the blood pressure was above 160 mmHg; the autonomic nervous system would appear to control the cochlear blood flow against large variations in blood flow in response to hypertensive phenomena.

Effect of nitric oxide blockade on the lower limit of the cortical cerebral autoregulation in pentobarbital-anaesthetized rats

The role of nitric oxide (NO) in cerebral autoregulation is controversial. The purpose of this study was to compare the effects on the lower limit of the cortical cerebral autoregulation of the inhibition of NO synthesis by N omega-nitro-L-arginine (L-NNA) infusion to saline and phenylephrine in pentobarbital-anaesthetized rats. Variations of the cortical cerebral blood flow (CBF), the cortical cerebrovascular resistances, the mean arterial pressure and the lower limit of cerebral autoregulation were compared in three groups: a group pretreated with L-NNA (n = 8), a group pretreated with saline (n = 8) and a group pretreated with phenylephrine (n = 5). The laser-Doppler flowmetry continuously measured CBF. Controlled haemorrhage was performed after the intravenous infusion of L-NNA, saline, or phenylephrine. The lower limit of cerebral autoregulation of each rat was computed by the least-squares method. The lower limit of cerebral autoregulation was significantly higher after L-NNA infusion (74 +/- 5 mm Hg) than after saline (43 +/- 3 mm Hg; p < 0.01) or phenylephrine infusions (52 +/- 5 mm Hg; p < 0.05). In conclusion, the role of NO on the cerebral autoregulation has been controversial; our results confirm the hypothesis that NO exerts a significant role in maintaining the lower limit of cerebral autoregulation in pentobarbital-anaesthetized rats.

Detection of gram-negative bacteraemia in early sepsis by a quantitative chromogenic and kinetic endotoxin assay. The Study Group

A kinetic chromogenic limulus test was carried out in order to investigate the possibility of a sensitive and specific detection of circulating endotoxin during the first 24 h of septic shock or severe sepsis in 76 patients. Two commercial kits, Whittaeker (W) and Chromogenix (C), were used. Blood culture was taken as a reference. At 1:10 plasma dilution (a currently used dilution in the end point limulus test) abnormal reaction kinetics were found in 13% and 41% of tests, for C and W respectively (P = 0.0008), resulting in unreliable results. Retesting plasma at a greater dilution, until the reaction kinetic was identical to calibration curve control values, gave similar results between the two kits and a better accuracy. Beyond a 0.5 EU mL-1 endotoxin level, the probability of Gram-negative bacteraemia was high (sensitivity = 0.53 and 0.47; specificity = 0.95 and 0.93 for C and W respectively). This kinetic limulus amoebocyte lysate (LAL) test may be useful in therapeutic decisions for treatment of endotoxaemia.

[Do corticotherapy and hemodilution decrease postoperative inflammation after maxillofacial surgery?]

OBJECTIVE

To assess the efficiency of corticosteroids and preoperative acute normovolaemic haemodilution (PANHD) in reducing postoperative inflammation after maxillofacial surgery.

STUDY DESIGN

Randomized clinical trial.

PATIENTS

Thirty-two patients scheduled to undergo maxillary osteotomy for facial dysmorphia were randomized into four groups of eight (PANHD or not; corticosteroids or not).

METHODS

PANHD decreased haematocrit to 30%. In the corticosteroid groups, methylprednisolone 1.5 mg.kg-1 was given intravenously at the beginning of surgery (after PANHD in haemodiluted group), and after surgery, 1.5 mg.kg-1 iv daily for three days. Postoperative inflammation was assessed with an X-Ray technique (radiotelemetry) providing data on tissue thickness (extent of facial oedema), and by measurement of plasma concentrations of four acute phase proteins during the first postoperative week.

RESULTS

No change in facial oedema and in acute phase proteins occurred with PANHD. Corticosteroids decreased postoperative oedema and acute phase proteins.

CONCLUSION

Corticosteroids decrease postoperative inflammation after maxillofacial surgery but not PANHD.

Acute normovolaemic haemodilution does not reduce the inflammatory process induced by facial surgery

The place of preoperative acute normovolaemic haemodilution (haematocrit = 28%-32%) in reducing postoperative inflammation was evaluated after facial surgery. Thirty-two patients scheduled for mandibular osteotomy were randomized to a nonhaemodiluted group or to a haemodiluted group. The degree of postoperative inflammation was evaluated: first by an x-ray technique (radiotelemetry) providing measurements of the tissue thickness (quantitation of facial oedema), and second by the measurement of four acute phase protein plasma concentrations during the first postoperative week. Throughout the study, no changes in facial oedema or in variation of acute phase proteins were detected after haemodilution. It is concluded that acute normovolaemic haemodilution has no effect on the intensity of facial oedema and the biological inflammation process after facial surgery.

Regional chemotherapy (with mitomycin C) and intra-operative hyperthermia for digestive cancers with peritoneal carcinomatosis

Intraperitoneal chemo-hyperthermia with mitomycin C was used to treat 28 patients with far advanced digestive adenocarcinoma and histologically confirmed peritoneal carcinomatosis. Surgical resection of the primary tumor was possible in 17 cases. After closure of the abdominal wall, intraperitoneal chemo-hyperthermia was performed for 90 to 120 minutes under general anesthesia and 32 degrees C hypothermia, through 3 intraperitoneal drains forming a closed circuit, using 10 mg/l of mitomycin C in 6 liters of peritoneal dialysate heated to an inflow temperature of 46-49 degrees C. No mortality occurred, and there were 2 post-operative complications, with transitory biological side effects. In 9 out of 10 patients with preoperative malignant ascites, the ascites cleared after treatment. One-year survival rate was 54.2%. These encouraging preliminary results show that intraperitoneal chemohyperthermia with mitomycin C is a safe and reliable treatment for peritoneal carcinomatosis in far advanced digestive cancers.

[Pain associated with the injection of Diprivan]

Pain at the site of propofol injection is a real problem which requires particular attention in children. In adults, undergoing planned surgery, premedication or opioid administration prior to propofol seem to sufficiently reduce the frequency and severity of the pain induced by the injection of the agent into a distal arm vein. Adding lidocaine to propofol just before the injection is debatable in day-case procedures, especially if the injection is carried out on the dorsum of the hand. In children, intravenous administration of lidocaine seems to be more routinely performed, whatever the type of surgery.

[Intra-abdominal pressure]

The abdominal pressure is a hydrostatic one, which can be measured in the bladder, the rectum and the stomach. In physiologic conditions, the abdominal pressure is variable, with peaks as high as 100 to 200 mmHg at the time of defecation, cough. The increase in abdominal pressure elicited by abdominal distension or compression acts directly on the abdominal compartment, indirectly on the thoracic compartment, and modifies the circulation and the ventilation. Venous return is decreased as the inferior vena cava is compressed. The systemic resistances are also increased as the abdominal vessels are compressed. Therefore the circulation is mainly distributed to the superior part of the body. Although the cardiac output is decreased, the usual haemodynamic parameters remain in the normal range: arterial pressure is increased, heart rate is unchanged, central venous pressure is increased, cardiac failure is unusual. The abdominal distension is also responsible for a restrictive respiratory syndrome, mainly due to the ascension of the diaphragm. The compression of the abdominal content explains renal effects and the decreased diuresis. A sustained increase in abdominal pressure occurs in several clinical conditions. During coelioscopy, abdominal pressure is a under control and the cardiovascular effects are minor. Insufflation with CO2 carries the risk of hypercapnia, gas embolism and pneumothorax. During abdominal tamponade, anuria is directly related to the level of pressures. At an abdominal pressure over 25 mmHg, anuria is common and decompression becomes essential. The G suit increases arterial pressure either by elevating vascular resistances or increasing blood content in the upper part of the body. Therefore cardiac tolerance can be decreased especially in cardiac patients. The adverse effects of abdominal pressure can also be observed in case of peritoneal dialysis and ascites. The risk of regurgitation associated with an increased abdominal pressure must also be kept in mind. The abdominal pressure plays an important role in anaesthesia as well as in surgery. Therefore its measurement, which is easy, should become a routine.

Effects of posture, hypotension and locally applied vasoconstriction on the middle ear microcirculation in anaesthetized humans

Studies by laser-Doppler flowmetry of middle ear microcirculation changes induced by physical and chemical stimuli in the animal have only recently been made. This prospective study, performed in humans, was designed to compare the effects of a postural manoeuvre (headup tilt 30 degrees), hypotension and locally applied vasoconstriction on middle ear blood flow during anaesthesia. Circulatory changes provoked by a headup tilt of 30 degrees, and successive intravenous boluses of potent vasodilators, were compared with circulatory changes provoked by locally applied adrenaline, in ten healthy patients in good physical states undergoing middle ear surgical repair. Heart rate and direct arterial pressure were continuously recorded via a radial artery cannula. Middle ear blood flow was continuously recorded via a laser-Doppler probe placed on the promontorium cavi tympani. Metabolic parameters (partial pressure of O2 and CO2 in arterial blood, pH, arterial lactate concentrations) and arterial concentrations of propofol were measured just before and just after the experiment. Headup tilt did not modify heart rate, mean arterial pressure or middle ear blood flow. Vasodilators (nicardipine, nitroprusside, nitroglycerin) provoked a fall in arterial pressure (P < 0.0001, P < 0.0001, P < 0.019, respectively), but did not induce any significant variations in heart rate; variations occurred in middle ear blood flow (P > 0.05, not significant) which were different according to patients and agents. Locally applied adrenaline provoked a fall in the middle ear blood flow (P < 0.0012), with no effect on heart rate and arterial pressure. There were no significant changes in metabolic values, or propofol serum concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

A new device for the treatment of pleural malignancies: intrapleural chemohyperthermia preliminary report

The prognosis of malignant pleural tumors remains extremely unfavorable. The aim of this study is to evaluate the combination of intrathoracic intrapleural chemotherapy and intrapleural hyperthermia (ITCH) in these diseases. Under anesthesia, 5 men were studied. After pleurectomy for mesothelioma (3/5) or adenocarcinoma (2/5), ITCH is carried out for over 60 min, either with mitomycin C (4/5) or cisplatin (1/5). No pre- or postoperative death occurred. The maximal pleural temperature is 42.6 degrees C. The blood level of mitomycin C never reached the systemic toxic level. All the patients were discharged from the surgical ward, 3 are still alive 15 months later. Therefore, ITCH appears to be a safe and reliable therapy.

Intraoperative chemohyperthermia in the management of digestive cancers. A general review of literature

Intraoperative chemohyperthermia is a new method in the treatment of peritoneal seedings from digestive cancers, which combines surgery, intraperitoneal chemotherapy (mitomycin C and/or cisplatyl) and peritoneal hyperthermia. After a brief reminder on the general principles concerning high temperature action, a review of literature is made: 5 teams have performed this technique. We differentiate the indications, design features and results of each team. The results show a mean survival after 2 years of 35% (in peritoneal carcinomatosis) up to 78% (in gastric serosal invasion, peritoneal seeding free). The best result of the method is the drying up of cancerous ascites, allowing a more comfortable survival.

[Hyperthyroidism induced by molar pregnancy]

A case is reported of a Senegalese patient admitted for hydatiform mole. The serum human chorionic gonadotrophin concentration (hCG) was 900,000 UI.l-1. The patient was recognized to be clinically hyperthyroid with raised T4 and T3 values, but a very low TSH concentration. After two days of beta adrenergic blockade and carbimazole, a suction curettage was performed under general anaesthesia. Propranolol was again administered 6 hours after the surgery. Thyroid function returned to normal level two weeks after removal of the mole, suggesting that hCG was responsible for the thyrotoxicosis. Serum hCG concentrations closely paralleled those of free thyroxine, but the correlation was difficult to assess because of carbimazole. Clinical thyrotoxicosis is rare in molar pregnancy. The diagnosis being made in semi-urgent conditions, this raises the question of how to obtain rapid stabilization of the disease before surgery.

Treatment of malignant peritoneal effusion in digestive and ovarian cancer

Intra Peritoneal Chemo Hyperthermia (IPCH) with Mitomycin C (MMC) or Cisplatinum (CP) was used to treat 32 patients with far advanced digestive or ovarian cancers and peritoneal carcinomatosis. Surgical resection of the primary tumor has been possible in 18 cases. After closure of the abdominal wall, a 90 minutes IPCH as performed under general anaesthesia and 32 degrees C general hypothermia, through 3 intraperitoneal drainages realizing a closed circuit, using 10 mg/l of MMC or 15 to 25 mg/l of CP in 6 l of peritoneal dialysate heated at the inflow temperature of 46 to 49 degrees C. The mortality rate was 3% and the morbidity rate was 3%. In 11 out of 12 patients with preoperative malignant ascites, no more ascites could be found after IPCH. For peritoneal carcinomatosis from digestive origin, median survival was 11.2 months and 1 year survival rate was 46.9%. These encouraging preliminary results show that IPCH is a safe and reliable treatment for peritoneal carcinomatosis in far advanced digestive or ovarian cancers.

[Local analgesic action by direct effect of pethidine on the nervous trunks]

The aim of this paper is to study the analgesic effects of meperidine (pethidine) on nervous trunks. First we compared the analgesic effect of pethidine in surgery of knee and femur. Meperidine was randomly administered either by femoral block or intravenously. The onset of analgesia was shorter with femoral block (5 minutes against 146 minutes). In the surgery of shoulder, nerve block with meperidine was performed using intersclalenic block. Plasma concentrations ar lower (maximum of 0.29 mg per liter) than intravenous therapeutic concentrations (between 0.5 and 0.7 mg per liter). So we can conclude as do other papers, there is a direct effect of meperidine on nervous trunks. This effect is probably mediated by receptors located on nervous trunks.

[Acute respiratory insufficiency in sickle cell disease]

Two cases are reported of acute respiratory failure occurring during sickling crises. In the first one, the crisis was characterised by priapism, and in the other one, by abdominal pain. The different causes of these respiratory effects are discussed: infection, fat embolism, pulmonary infarct, haemodynamic pulmonary oedema, as was probably the case in the first patient, or non haemodynamic pulmonary oedema due to sickling, as during conventional treatment of a sickling crisis (oxygen, antibiotics, blood transfusion, cytapheresis). Invasive investigations may contribute to keeping up the clinical picture, because of hypoxic sickling. The water equilibrium of these patients must be monitored with great care. Worsening of the patient's condition despite 48 h of correct treatment must lead to the search for a specific cause.

Effects of hypotension on cutaneous and subcutaneous blood flow in anaesthetized humans

The aim of this study was to determine the effect of controlled hypotension on subcutaneous and cutaneous haemodynamics in humans. Moderate hypotension was achieved with nitroglycerin (NTG) and sodium nitroprusside (SNP) infusion during narconeuroleptanalgesia in seven patients. Subcutaneous and cutaneous blood flow were measured by a superficial and deep heat clearance (HC) technique. The mean arterial pressure (BPa) decreased by 23%-30% and heart rate (fc) increased but only during NTG infusion (+22%; P less than 0.02). Subcutaneous and cutaneous blood flows remained unchanged despite a significant decrease in calculated cutaneous resistance (NTG: -26%, P less than 0.01; SNP: -34%, P less than 0.02] and subcutaneous vascular resistance changed only with SNP (-31%, P less than 0.02). After hypotension was discontinued the subcutaneous blood flow decreased (-13%, P = 0.05), whereas subcutaneous vascular resistance returned to its control values. An inverse relationship was found between fc and BPa (NTG: r = -0.525, P less than 0.01; SNP: r = -0.622, P less than 0.01) as well as with subcutaneous blood flow (NTG: r = -0.653, P less than 0.001; SNP: r = -0.573, P less than 0.01). In addition, we found oscillatory changes in deep HC values which differed in magnitudes (NTG 0.22 (SEM 0.09) W.m-1.degree C-1 vs SNP 0.42 (SEM 0.1) W.m-1.degrees C-1, P less than 0.01) and frequencies (NTG 0.02 (SEM 0.006) Hz vs SNP 0.01 (SEM 0.002) Hz, P less than 0.01). Despite unchanged blood flow, the effects of controlled hypotension on cutaneous and subcutaneous haemodynamics were different depending on the type of drug. These differences may have been related to counterregulatory responses and/or to direct vascular effects.

Mixed venous oxygen saturation in abdominal aortic surgery: intraoperative hypothermia and vasodilator therapy implications

This prospective study was designed to test the hypothesis that intraoperative hypothermia occurring during abdominal aortic surgery and vasodilator therapy used to avoid severe consequences of aortic clamping could both disturb the mixed venous oxygen saturation signal (SVO2). Twenty high risk surgical patients, ASA physical status II or III, were catheterized with the standard pulmonary artery catheter; SVO2 was determined by direct spectrophotometric measurements of oxygen haemoglobin concentration of serial samples. The relationships between SVO2, haemodynamic, metabolic variables and core temperature were analyzed. Haemodynamic values and oxygen transport were stable while inadequate tissue oxygenation occurred. A significant correlation was found between SVO2 and CI (r = 0.59, p less than 0.01), SVO2 and SVRI (r = -0.4, p less than 0.01), SVO2 and CT (r = -0.46, p less than 0.01), SVO2 and VO2 (r = -0.76, p less than 0.001). SVO2 and Qs/Qt (r = 0.83, p less than 0.001), SVO2 and EO2 (r = -0.75, p less than 0.001. No correlation was observed between SVO2 and lactacidemia (r = 0.04, p less than 0.05). Satisfactory haemodynamic stability and oxygen transport steady-state were the main conditions for a significant correlation between SVO2 and haemodynamic factors. However, there was no correlation between SVO2 and inadequate tissue oxygenation. SVO2 reflected only oxygen extraction. Intraoperative hypothermia provided an increased haemoglobin affinity for oxygen. Vasodilator therapy which allowed a decrease in systemic vascular resistance produced an increase in the left-right shunt and in venous oxygen admission. Thus hypothermia and vasodilator therapy could be both responsible for the elevated SVO2 occurring during infrarenal abdominal aortic surgery.

[Practical aspects of indirect calorimetry in post-anesthesia recovery]

The application of indirect calorimetry among intensive care patients is usually considered as a complicate technique, owing to the difficulties to interpret the bulk of obtained data. As a matter of fact, the variability of energy expenditure (EE) among these patients leads to prefer continuous measurements. This variability is related to interindividual variations as well as variations in the same patient (variations due to body temperature, activity state, diet-induced thermogenesis...). A computer program of data storage and calculations was developed. It allows: on-line storage as well as numerical and graphic display of VO2, VCO2, RQ and EE; menu-driven storage of all occurring events; automatic suppression of the recordings made after ventilator alarms; graphic printing and metabolic calculations. The two main indications for indirect calorimetry are the determination of actual EE and VO2 monitoring in acute states.

Intraoperative glucose infusion and blood lactate: endocrine and metabolic relationships during abdominal aortic surgery

The hypothesis that increased intraoperative blood lactate depends both on intraoperative glucose supply and inadequate tissue oxygenation occurring during surgery was tested in anesthetized patients undergoing infrarenal abdominal aortic surgery. Twenty surgical patients received either Ringer's solution or 5% glucose solution for intraoperative volume loading. Arterial blood lactate, arterial glucose, hemodynamic variables, insulin, glucagon, cortisol, epinephrine, and norepinephrine were determined preoperatively and intraoperatively. There were no significant changes in hemodynamic values, glucagon, norepinephrine, and epinephrine compared with control values in both groups. Oxygen consumption decreased only during aortic clamping. Cortisol and lactate increased significantly 10 min after aortic clamping until the end in both groups. Glucose 5% solution infusion resulted in significantly greater blood lactate accumulation and significantly greater blood glucose and insulin levels, whereas there were no changes in the patients receiving Ringer's solution. From control until aortic clamping, lactate and glucose were significantly correlated with each other in both groups; after aortic clamping until the end of the procedure, the correlation remained constant in patients in the Ringer's group, whereas no relationship could be demonstrated in those in the glucose group. The authors conclude that intraoperative glucose administration increases intraoperative blood lactate and that blood lactate accumulation depends both on glucose supply and tissue oxygen deficit. Furthermore, none of the hemodynamic metabolic and endocrine factors were reliable for assessing tissue perfusion and metabolic demands during surgery.

Auditory evoked potentials during propofol anaesthesia in man

The effects of propofol on auditory evoked potentials were studied in nine patients undergoing otorhinolaryngology surgery. After recording of basal evoked potentials patients received propofol 2 mg kg-1 over 2-3 min for induction of anaesthesia. Potentials were recorded every 10 min (T1, T2, T3). During T1, T2, T3, the infusion rates of propofol for maintenance of anaesthesia were respectively 7, 5 and 3 mg kg-1 h-1 consecutively. Middle latency component was affected markedly. Brainstem waves latencies I, III, V were increased significantly, while amplitude waves I, III, V remained constant.

Corynebacterium JK: surgical infections in non-immunosuppressed patients

Infection caused by Corynebacterium JK (CJK) has been recently described in immunocompromised patients. To evaluate the frequency of CJK infection among surgical and trauma intensive care patients, all patients with CJK isolations at clinical sites were reviewed. The criteria used were the presence of bacterial infection symptoms, isolation from significant sites and the efficiency of a vancomycin treatment. Eight patients were studied; 3 of them were considered infected, while 5 were judged only colonized. It is concluded that CJK infections can be a clinical problem in surgical trauma patients.

Cutaneous and subcutaneous blood flow during general anaesthesia

The vasodilator effect of anaesthetic agents on cutaneous vessels has often been investigated. In contrast, although subcutaneous tissue is concerned with metabolism and thermoregulation, the effects of anaesthesia on subcutaneous blood flow have not been well documented. The purpose of this study was to determine the magnitude of changes in cutaneous and subcutaneous blood flow during general anaesthesia in Man. Anaesthesia was induced with flunitrazepam in 15 patients before facial plastic surgery. Blood flow was estimated using heat thermal clearance (HC). Two HC sensors in different areas allowed the measurement of superficial and deep HC. Systolic (SABP), diastolic (DABP) and mean arterial blood pressure (MABP), heart rate (HR), and rectal and mean skin temperature were also recorded. After induction of anaesthesia, HR increased significantly (p less than 0.05) whereas SABP, DABP and MABP remained unchanged. The rectal-toe temperature gradient fell from 6.3 +/- 4.1 degrees C to 3.4 +/- 1.1 degrees C (p less than 0.01) suggesting a reduction in vasomotor tone. Superficial HC increased from 0.37 +/- 0.06 to 0.42 +/- 0.08 W.m-1.degrees C-1 (p less than 0.05) whereas deep HC decreased from 0.33 +/- 0.07 to 0.31 +/- 0.09 W.m-1.degrees C-1 (NS) and returned to the control value thereafter. Rectal temperature and mean skin temperature were unchanged. The changes in deep HC are similar to those previously observed in muscle during induction of anaesthesia. Our results show that anaesthesia mainly affects cutaneous blood flow, without any significant change in subcutaneous blood flow during the early phase of anaesthesia in human beings.

[Regional anticoagulation with citrate in hemodialysis in patients with a high risk for hemorrhage]

During haemodialysis in the patient at high risk for bleeding, heparin cannot be safely used to prevent clotting in the dialysis assembly. Among numerous procedures proposed to reduce the risk for bleeding, Pinnick et al. (N Engl J Med, 308: 258, 1983) proposed the use of citrate as the sole anticoagulant. Citrate toxicity and efficiency were studied during 44 haemodialyses carried out in thirteen patients with a high risk for bleeding or with active bleeding. Three patients had hepatic failure. Two types of citrate solution were used, the trisodium form of citrate (102 mmol.l-1 citrate) or the monosodium form (306 mmol.l-1 citrate). The solutions were infused with a calibrated, pressure insensitive pump, before the dialysis unit at a flow rate of 600 ml.h-1 and 200 ml.h-1 respectively. Sufficient citrate was infused to maintain a clotting time of the blood line and dialyser of more than 18 min. Standard 10% calcium chloride was infused at a constant rate of 7 mg.min-1 into the blood being returned to the patient. The patients were dialysed for 4 h for each haemodialysis with a single-pass system. The dialyses were uncomplicated; no active bleeding was noted. The patient's clotting time was significantly reduced during haemodialysis (18.1 +/- 8.9 min to 14.5 +/- 6.3 min; p less than 0.001). Two-hundred and twenty serum citrate levels were measured. Only nine were above the toxic value of 2 mmol.l-1. No clinical evidence of a decrease in ionized calcium was found: there was no change in the corrected QT intervals and blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hemodynamic parameters and blood-free surgical field with nitroglycerin in maxillofacial surgery]

73 oral facial surgery have been performed using controlled-hypotension induced with nitroglycerin (NTG) to reduce surgical bleeding. Surgical bleeding has been reduced in more than 45% of cases. But frequent lack of correlation between blood pressure, heart beat and bleeding might imply vascular reflex mechanisms induced by controlled-hypotension using NTG. Hemodynamic parameters such as blood pressure and heart rate seem to be insufficient to monitor controlled hypotension efficiency on surgical bleeding. The use of peroperative tissues blood flow monitoring may help for the better understanding of surgical bleeding during controlled-hypotension using NTG.

[Evaluation of the Engstrom metabolic computer]

The Engstrom Metabolic Computer (EMC), in association with the Erica Ventilator, uses indirect calorimetry to carry out continuous on-line gas exchange measurements. A laboratory assessment of the different parts of this equipment is described. The variability of FIO2 was less than 0.05. The accuracy and stability of the inspiratory flowmeter were only slightly modified by changes in the I/E ratio and gas flow rates. The overestimation of flow on increasing FIO2 was taken into account by the computer. The hygrometry of inspiratory and expiratory air samples reached that of room air, with an absence of saturation during prolonged measurements. The CO2 analyser also showed a good stability. The accuracy of the oxygen cell needed to be checked periodically. A global evaluation was carried out using Damask's method: a lung model was used into which CO2 and N2 were insufflated at precise rates to simulate CO2 production and O2 consumption. The measured respiratory quotient was also compared with the known RQ of burning methanol. The difference between measured and real values was less than 5%. Therefore, it was concluded that the EMC was reliable for indirect calorimetry measurements.

Changes in skin thermal clearance during anaesthesia

Thermal and vascular side effects occurring during general anaesthesia are related to skin blood flow. A new, noninvasive probe which measures skin thermal clearance, a variable closely related to skin blood flow, was used in nine patients under phenoperidine, droperidol, propanidid anaesthesia. Statistically significant increases in skin thermal clearance clearly preceded the drop in mean arterial blood pressure and the rise in skin temperature. It is concluded that general anaesthesia induced an early increase in skin blood flow and that thermal clearance is a better technique than skin thermometry to monitor skin blood flow.

[Creatine phosphokinases and serum and urinary myoglobin following a procedure in prolonged knee-chest position for the treatment of spondylolisthesis]

Rhabdomyolysis following the knee-chest position was studied in 15 patients scheduled for surgery for spondylolisthesis. A comparison was made between 11 patients scheduled for orthopaedic surgery: ligamentoplasty (6 patients), total hip prosthesis (5 patients) and 11 patients scheduled for long oral surgery. The measurements carried out were blood CPK before surgery, 4, 8, 12 and 24 h after the beginning of surgery, and at days 2, 3 and 4. Blood and urinary myoglobin were measured at days 1, 2, 3 and 4 after surgery. The results were tested with the Mann and Whitney test. There was no statistical change in CPK and myoglobin in the test population. Following the knee-chest position, there was a statistical increase of CPK in all patients, with great individual variations. Myoglobinaemia and myoglobinuria were observed in six patients, these not being correlated with the variations of CPK. Nevertheless, the maximal increase of CPK and myoglobin was seen in one patient, without any modification of diuresis but with an increase of creatininaemia at 220 mmol X l-1. In this series, rhabdomyolysis was real. CPK was not a good index of the release of haematic pigments, the only dangerous ones. A qualitative search for myoglobinuria is suggested, this being followed, or not, by alkalization to prevent acute renal failure.

[Femoral nerve block as a postoperative analgesia technic in surgery of the knee]

A femoral nerve block was performed as a postoperative analgesic technique in 50 patients after knee surgery; this surgery is a very painful one. The technique used was the inguinal route, as described in the textbooks. Bupivacaine was used: 1.5 mg X kg-1 without exceeding 150 mg. The result was good in 46 patients, with four failures. The average duration of analgesia was 600 min, the shortest being 300 min, the longest being 1,200 min. This technique can be recommended after surgery of the knee as safe and reliable.

[A severe form of heat stroke in a long-distance runner]

A case of a severe heat stroke is reported in a 30 yr old white man while running a long-distance race. At the time of admission, moderate hyperthermia (40 degrees C) and coma were two major symptoms found at physical examination. Within 24 h, the clinical picture evolved to multiple organ failure with marked rhabdomyolysis, acute renal failure with hyperkalaemia and lactic acidosis. At this time, were also found a consumptive coagulopathy and acute hepatic failure. After numerous complications, most of them infectious, the patient was discharged after four months in ICU and admitted in a physical rehabilitation department. Muscle biopsy performed three years after the heat stroke showed an abnormal reactivity to caffeine, but a normal reaction to halothane. The relationship between malignant hyperthermia and heat stroke remains uncertain.

[Post-traumatic hyperthyroxinemia or hyperthyroidism]

A fifteen year-old girl presented with several fractures after a road traffic accident. Five days later, fat embolism occurred, complicated by adult respiratory distress syndrome (ARDS) and disseminated coagulation (DIC). She was successfully managed in the intensive therapy unit, and was transferred to a general surgery after five weeks. Tachycardia and fever persisted without any other sign of infection. Clinical examination showed exophthalmos and a thyroid murmur. The venous concentration of T4 was increased: 204 nmol . 1(-1) (N: 70-150), whereas that of T3 was normal: 2.3 nmol . 1(-1) (N: 1-1.25). No other investigations were performed. The regression of clinical symptoms and a normalization of T4 were seen after treatment (carbimazole and acebutolol). Post-traumatic hyperthyroidism is discussed. Although classical, this syndrome was not well documented, as was shown in the literature survey. After trauma or an acute illness, an early fall in thyroid hormone concentrations was usually seen; a late increase in T4 was a rare occurrence.