Morphological quantitative analysis of intracranial pressure waves in normal pressure hydrocephalus

This work presents a prospective morphological and quantitative analysis of 43 intracranial pressure recordings performed on normal pressure hydrocephalic patients. This analysis led us to separate Lundberg's B waves into different subtypes and to refine the definition of the 'Plateau' wave. Two B wave subtypes named Great Symmetrical wave and Intermediate wave appeared correlated with the surgical improvement. In addition, the degree of post-operative improvement was correlated with the frequency of Intermediate wave. An extended quantitative classification of intracranial pressure waves is proposed that can be used alone to determine which patients should undergo a shunting procedure and which one should the most improve.

The effect of analgesic state on implicit learning during propofol anesthesia in volunteers

Noxious stimulation may enhance implicit learning during general anesthesia. It is unknown, however, whether analgesic state can influence this memory processing. Twenty healthy adult volunteers were enrolled our prospective, double-blinded, controlled experiments. Anesthesia was induced with a propofol target controlled infusion (TCI), titrated in step-wise increments to loss of consciousness. In phase A, a 10-word list was played to the subjects while a noxious stimulus was applied (hand immersion in cold water at 2-4 degrees C). In phase B, a remifentanil TCI infusion was added to the steady-state propofol TCI anesthesia, and titrated to loss of hand movement on cold water immersion. A second 10-word list was then played while maintaining the hand in cold water. Memory testing, 2 hours post-recovery revealed no evidence of explicit memory in any subject during either phase of the study. During phase A, the word stem completion test revealed implicit learning for played words. In contrast, no implicit memory was detected during phase B. This study indicates that analgesia with remifentanil TCI (titrated to loss of movement on noxious stimulation), prevented implicit memory processing during stable propofol anesthesia in healthy adult volunteers.

Absence of implicit and explicit memory during propofol/remifentanil anaesthesia

BACKGROUND AND OBJECTIVE

High doses of opioid associated with low doses of hypnotic is a popular anaesthetic technique since the use of remifentanil has become widespread. This type of anaesthesia could result in a higher incidence of implicit memory.

METHODS

Ten patients were anaesthetised with a target-controlled infusion of remifentanil (target concentration of 8 ng mL(-1)) combined with a target-controlled infusion of propofol with progressive stepwise increases until loss of consciousness was reached. A tape containing 20 words was then played to the patients. Bispectral index (BIS, Aspect Medical Systems, Newton, MA, USA) was continuously monitored during the whole study period. Implicit and explicit memories were tested between 2 and 4 h after recovery.

RESULTS

Loss of consciousness was obtained with a mean calculated propofol plasma concentration of 1.3 +/- 0.4 microg mL(-1). At this low hypnotic concentration no implicit or explicit memory was found in the three postoperative memory tests. Median (range) BIS value during word presentation was 93 (80-98).

CONCLUSIONS

In our group of young American Society of Anesthesiologists (ASA) I/II patients, no explicit or implicit memory was found when the calculated concentration of propofol combined with a high concentration of remifentanil was maintained at the level associated with loss of consciousness with high BIS values.

Effect site concentrations of remifentanil and pupil response to noxious stimulation

BACKGROUND

Opioid drugs block reflex pupillary dilatation in response to noxious stimulation. The relationship between the target effect site concentration (Ce(T)) of remifentanil and the pupil diameter and reactivity in response to a standard noxious stimulus were evaluated.

METHODS

Anaesthesia was induced with propofol TCI to obtain loss of consciousness (LOC) in 12 ASA I/II patients. Thereafter, remifentanil Ce(T) was titrated by increments of 1 up to 5 ng ml(-1). In the awake state, at LOC and at each plateau level of remifentanil Ce(T), arterial pressure, heart rate, and BIS (A2000) were recorded. Pupil size and dilatation after a 100 Hz tetanic stimulation (T100) were measured at LOC and at each plateau level of remifentanil Ce(T).

RESULTS

LOC was observed at a mean propofol Ce(T) of 3.53 (SD 0.43) microg ml(-1). Arterial pressure and heart rate decreased progressively from LOC to 5 ng ml(-1) remifentanil Ce(T) without any statistical difference between each incremental dose of remifentanil. Mean BIS values decreased from 96 (2) in the awake state, to 46 (12) at LOC (P<0.05) and then remained unchanged at all remifentanil Ce(T). Pupil dilatation in response to 100 Hz tetanic stimulation decreased progressively from 1.55 (0.72) to 0.01 (0.03) mm and was more sensitive than pupil diameter measured before and after 100 Hz tetanus. An inverse correlation between pupil dilatation in response to 100 Hz tetanus and an increase in remifentanil Ce(T) from 0 to 5 ng ml(-1) was found (R(2)=0.68).

CONCLUSIONS

During propofol TCI in healthy patients, the decrease in pupil response to a painful stimulus is a better measurement of the progressive increase of remifentanil Ce(T) up to 5 ng ml(-1) than haemodynamic or BIS measurements.

Absence of explicit and implicit memory in unconscious patients using a TCI of propofol

BACKGROUND

Episodes of implicit memory have been described during propofol anaesthesia. It remains unclear whether implicit memory is caused by short periods of awareness or occurs in an unconscious subject.

METHODS

Sixty patients were randomized in an experimental group (EG), a control group (CG) and a reference group (RG). Loss of consciousness (LOC) was obtained by progressive stepwise increases of propofol using a target-controlled infusion device (Diprifusor, Alaris Medical Systems, San Diego, CA). A tape containing 20 words was played to the patients in the CG before the start of anaesthesia and to the patients in the EG at a constant calculated concentration of propofol associated with LOC. The tape was not played to the patients in the RG. Three memory tests were performed postoperatively.

RESULTS

Explicit and implicit memories were evidenced in the CG but not in the EG.

CONCLUSION

In our group of young ASA I/II patients, in the absence of any noxious stimulus, no implicit or explicit memory was found when the calculated concentration of propofol using a Diprifusor was maintained at the level associated with LOC.

Target-controlled infusion of propofol induction with or without plasma concentration constraint in high-risk adult patients undergoing cardiac surgery

BACKGROUND

Calculated plasma (Cp) and calculated effect site concentrations (Ce) of propofol associated with loss of consciousness (LOC) have been studied in young healthy patients. The aim of the study was to evaluate the calculated propofol concentrations required to induce LOC in ASA III adult patients undergoing cardiac surgery using a smooth target controlled infusion of propofol.

METHODS

After informed consent, 44 patients were premedicated with 0.5 mg alprazolam orally. Propofol TCI using the pharmacokinetic set of Marsh et al. incorporated in the Diprifusor (ThalfKeo of 2.6 min) was used. Propofol Ce was progressively increased by 0.5 micro g/ml until LOC was obtained. The constraint on the maximum gradient between Cp and Ce was either 1 micro g/ml in group 1 or not limited in group 2. Hemodynamic variations were assessed.

RESULTS

Mean preoperative left ventricular ejection fractions were 44 +/- 15.4% and 56 +/- 11.4% in groups 1 and 2, respectively (P < 0.01). At LOC, mean Cp was 1.9 micro g/ml in both groups but mean Ce was 1.08 +/- 0.31 and 1.43 +/- 0.42 micro g/ml in groups 1 and 2, respectively (P < 0.01). The mean induction time was 12.8 +/- 7.1 min in group 1 and 8.5 +/- 2.7 min in group 2 (P < 0.05). No episode of hypotension has been observed in either group.

CONCLUSION

In ASA III patients undergoing cardiac surgery, smooth propofol TCI induction, using the pharmacokinetic set of Marsh et al. incorporated in the Diprifusor, is associated with LOC at a low mean calculated plasma concentration of 1.9 micro g/ml and good hemodynamic stability.

Predictive accuracy of target-controlled propofol and sufentanil coinfusion in long-lasting surgery

BACKGROUND

The predictive accuracy of target concentration infusions of propofol has been documented only for less than 4 h, and no prospective study of sufentanil target controlled infusion is available. The authors investigated the predictive accuracy of pharmacokinetic models for propofol and sufentanil coadministered during long-lasting surgery.

METHODS

Ten patients, American Society of Anesthesiologists physical status I and II, were studied during extended cervicofacial surgery. Target controlled infusion of propofol and sufentanil was administered during surgery using decisional algorithms, taking into consideration pain assessment, hemodynamic changes, and peroperative blood losses. Intrasubject data analysis included calculation of performance error, median performance error, median absolute performance error, divergence, and wobble.

RESULTS

The range of plasma target concentrations was 2-5 microgram/ml for propofol and 0.2-1 ng/ml for sufentanil. Median performance error was -12.1% for propofol and -10% for sufentanil. The wobble values were 11.6% and 22.3% for propofol and sufentanil, respectively. The pharmacokinetic sets used slightly overpredicted the concentrations, with negative values of divergence of 2.92% and 0.22% units/h for propofol and sufentanil, for a mean infusion period of 762 min.

CONCLUSIONS

This prospective study demonstrates the predictive accuracy of the pharmacokinetic model for sufentanil infusion and confirms that for propofol during long-lasting surgery using standardized rules for the management of target controlled infusion and blood loss replacement.

Pharmacokinetic model-driven infusion of sufentanil and midazolam during cardiac surgery: assessment of the prospective predictive accuracy and the quality of anesthesia

OBJECTIVE

To evaluate the prospective predictive accuracy and the quality of anesthesia of pharmacokinetic model-driven infusion of sufentanil and midazolam designed to establish and maintain a plasma level of drug during cardiac surgery.

DESIGN

Prospective analysis.

SETTING

Operating room at a university hospital.

PARTICIPANTS

Twenty adult patients younger than 75 years old scheduled for valvular or coronary artery bypass graft surgery.

INTERVENTIONS

Patients were anesthetized using a variable predicted concentration of sufentanil (1 to 10 ng/mL) combined with a stable predicted concentration of midazolam (100 ng/mL).

MEASUREMENTS AND MAIN RESULTS

For each patient, arterial samples were taken before (6 samples), during (2 samples), and after (2 samples) cardiopulmonary bypass (CPB). Plasma sufentanil and midazolam concentrations were measured by specific radioimmunoassay and high-performance liquid chromatography techniques. Predicted sufentanil and midazolam concentrations were derived using the data sets of Gepts et al and Maitre et al. The predictive performance, the percentage prediction error (PE), and the absolute percentage error were calculated for each sample. The bias, inaccuracy, and dispersion were assessed by determining the median of the individual medians of the prediction errors (MDPE), the median of the individual median of the absolute prediction errors (MDAPE), and the 10th and 90th percentiles of PE. For midazolam, the inaccuracy was low (MDAPE < 21%), but CPB was associated with a dilution of the measured concentration associated with a negative bias. For sufentanil, the inaccuracy was also low before CPB (MDAPE = 18%) but increased during and after CPB (MDAPE > 40%). During the whole procedure, the hemodynamic control necessitated only a few interventions.

CONCLUSIONS

Pharmacokinetic model-driven infusion of sufentanil and midazolam using the pharmacokinetic sets of Gepts et al and Maitre et al is a safe and accurate anesthetic technique before CPB in adult patients undergoing cardiac surgery when high sufentanil (1 to 10 ng/mL) and low midazolam (100 ng/mL) predicted plasma concentrations are targeted.

Acute renal failure in the ICU: risk factors and outcome evaluated by the SOFA score

OBJECTIVES

To describe risk factors for the development of acute renal failure (ARF) in a population of intensive care unit (ICU) patients, and the association of ARF with multiple organ failure (MOF) and outcome using the sequential organ failure assessment (SOFA) score.

DESIGN

Prospective, multicenter, observational cohort analysis.

SETTING

Forty ICUs in 16 countries.

PATIENTS

All patients admitted to one of the participating ICUs in May 1995, except those who stayed in the ICU for less than 48 h after uncomplicated surgery, were included. After the exclusion of 38 patients with a history of chronic renal failure requiring renal replacement therapy, a total of 1411 patients were studied.

MEASUREMENTS AND RESULTS

Of the patients, 348 (24.7%) developed ARF, as diagnosed by a serum creatinine of 300 micromol/l (3.5 mg/dl) or more and/or a urine output of less than 500 ml/day. The most important risk factors for the development of ARF present on admission were acute circulatory or respiratory failure; age more than 65 years, presence of infection, past history of chronic heart failure (CHF), lymphoma or leukemia, or cirrhosis. ARF patients developed MOF earlier than non-ARF patients (median 24 vs 48 h after ICU admission, p < 0.05). ARF patients older than 65 years with a past history of CHF or with any organ failure on admission were most likely to develop MOF. ICU mortality was 3 times higher in ARF than in other patients (42.8% vs 14.0%, p < 0.01). Oliguric ARF was an independent risk factor for overall mortality as determined by a multivariate regression analysis (OR = 1.59 [CI 95%: 1.23-2.06], p < 0.01). Infection increased the risk of death associated with all factors. Factors that increased the ICU mortality of ARF patients were a past history of hematologic malignancy, age more than 65 years, the number of failing organs on admission and the presence of acute cardiovascular failure.

CONCLUSION

In ICU patients, the most important risk factors for ARF or mortality from ARF are often present on admission. During the ICU stay, other organ failures (especially cardiovascular) are important risk factors. Oliguric ARF was an independent risk factor for ICU mortality, and infection increased the contribution to mortality by other factors. The severity of circulatory shock was the most important factor influencing outcome in ARF patients.

Salivary biomass assessed by bioluminescence ATP assay related to (bacterial and somatic) cell counts

The present work aimed (1) to evaluate ATP content in saliva by the bioluminescent luciferin-luciferase method, (2) to evaluate the relationships between ATP content, bacterial count and epithelial cell numbers in saliva, (3) to study the effect of two different antiseptics (peroxidase system producing hypothiocyanite and chlorhexidine) on the salivary biomass. In 45 young adults, the salivary ATP content ranged from 8 to 1515 nM. Salivary ATP content was significantly and directly correlated to bacterial count and epithelial cell numbers (Spearman-Rank correlation, P< or =0.001). Regression analysis allowed the inference of a mean epithelial cell and bacterial ATP content of 152.7 fg and 8.3 fg per cell, respectively. The salivary ATP content decreased significantly to 38. 8+/-12.3 per cent (mean+/-SEM, N=6) of its initial value after a 30-min incubation in the presence of a peroxidase system producing hypothiocyanite (OSCN(-)). Chlorhexidine (CHX) reduced salivary ATP content to 52.0+/-16.7 per cent. OSCN(-) did not affect the transformed logarithm of bacterial count but CHX reduced it from 7. 02+/-0.26 to 0.52+/-0.33. No effect of OSCN(-) was seen on the ratio of epithelial cell viability while CHX reduced it from 46.7+/-5.1 to 3.9+/-1.1 per cent. It is concluded that the combination of the evaluations of the ATP content and cell numbers in saliva can provide reliable data about the effects of oral antiseptics on salivary biomass.

The use of maximum SOFA score to quantify organ dysfunction/failure in intensive care. Results of a prospective, multicentre study. Working Group on Sepsis related Problems of the ESICM

OBJECTIVE

To evaluate the performance of total maximum sequential organ failure assessment (SOFA) score and a derived measure, delta SOFA (total maximum SOFA score minus admission total SOFA) as a descriptor of multiple organ dysfunction/failure in intensive care.

DESIGN

Prospective, multicentre and multinational study.

SETTING

Forty intensive care units (ICUs) from Australia, Europe, North and South America.

PATIENTS

Data on 1,449 patients, evaluated at admission and then consecutively every 24 h until ICU discharge (11,417 records) during May 1995. Excluded from data collection were all patients with a length of stay in the ICU less than 2 days following uncomplicated scheduled surgery.

MAIN OUTCOME MEASURE

Survival status at ICU discharge.

INTERVENTIONS

The collection of raw data necessary for the computation of a SOFA score on admission and then every 24 h, and basic demographic and clinical statistics.

MEASUREMENTS AND MAIN RESULTS

Mean total maximum SOFA score presented a very good correlation to ICU outcome, with mortality rates ranging from 3.2% in patients without organ failure to 91.3% in patients with failure of all the six organs analysed. A maximum score was reached 1.1 +/- 0.2 days after admission for all the organ systems analysed. The total maximum SOFA score presented an area under the ROC curve of 0.847 (SE 0.012), which was significantly higher than any of its individual components. The cardiovascular score (odds ratio 1.68) was associated with the highest relative contribution to outcome. No independent contribution could be demonstrated for the hepatic score. No significant interactions were found. Principal components analysis demonstrated the existence of a two-factor structure that became clearer when analysis was limited to the presence or absence of organ failure (SOFA score > or = 3 points) during the ICU stay. The first factor comprises respiratory, cardiovascular and neurological systems and the second coagulation, hepatic and renal systems. Delta SOFA also presented a good correlation to outcome. The area under the receiver operating characteristic (ROC) curve was 0.742 (SE 0.017) for delta SOFA, lower than the total maximum SOFA score or admission total SOFA score. The impact of delta SOFA on prognosis remained significant after correction for admission total SOFA.

CONCLUSIONS

The results show that total maximum SOFA score and delta SOFA can be used to quantify the degree of dysfunction/failure already present on ICU admission, the degree of dysfunction/failure that appears during the ICU stay and the cumulative insult suffered by the patient. These properties make it a good instrument to be used in the evaluation of organ dysfunction/failure.

Use of the SOFA score to assess the incidence of organ dysfunction/failure in intensive care units: results of a multicenter, prospective study. Working group on "sepsis-related problems" of the European Society of Intensive Care Medicine

OBJECTIVE

To evaluate the use of the Sequential Organ Failure Assessment (SOFA) score in assessing the incidence and severity of organ dysfunction in critically ill patients.

DESIGN

Prospective, multicenter study.

SETTING

Forty intensive care units (ICUs) in 16 countries.

PATIENTS

Patients admitted to the ICU in May 1995 (n = 1,449), excluding patients who underwent uncomplicated elective surgery with an ICU length of stay <48 hrs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The main outcome measures included incidence of dysfunction/failure of different organs and the relationship of this dysfunction with outcome. In this cohort of patients, the median length of ICU stay was 5 days, and the ICU mortality rate was 22%. Multiple organ dysfunction and high SOFA scores for any individual organ were associated with increased mortality. The presence of infection on admission (28.7% of patients) was associated with higher SOFA scores for each organ. The evaluation of a subgroup of 544 patients who stayed in the ICU for at least 1 wk showed that survivors and nonsurvivors followed a different course. This subgroup had greater respiratory, cardiovascular, and neurologic scores than the other patients. In this subgroup, the total SOFA score increased in 44% of the nonsurvivors but in only 20% of the survivors (p < .001). Conversely, the total SOFA score decreased in 33% of the survivors compared with 21% of the nonsurvivors (p < .001).

CONCLUSIONS

The SOFA score is a simple, but effective method to describe organ dysfunction/failure in critically ill patients. Regular, repeated scoring enables patient condition and disease development to be monitored and better understood. The SOFA score may enable comparison between patients that would benefit clinical trials.

Visual evaluation of residual curarization in anesthetized patients using one hundred-hertz, five-second tetanic stimulation at the adductor pollicis muscle

We were looking for a clinical test to indicate a train-of-four (TOF) ratio of approximately 0.9. We compared the adductor pollicis muscle (AP) visually evaluated response to ulnar nerve 100-Hz, 5-s tetanus (RF100 Hz) with the measured AP TOF ratio in 30 ASA physical status I or II adult anesthetized (propofol, sufentanil, N2O/O2) patients. After the induction of anesthesia, the left ulnar nerve was stimulated at the wrist (single twitch and TOF) and the resultant isometric force was measured. When TOF was assessed, the independent investigators, unaware of the left AP-measured TOF ratios, visually evaluated the presence or absence of AP fading elicited by right ulnar nerve 100-Hz, 5-s tetanus. The 30 patients were randomly allocated to receive either 0.5 mg/kg atracurium (n = 15) or 0.1 mg/kg vecuronium (n = 15). The neuromuscular blockade was allowed to resolve spontaneously. A multiple logistic regression analysis was performed by computing the 771 visual observations. The probabilities of success of 100-Hz, 5-s tetanus to detect TOF ratios of 0.8, 0.85, and 0.9 were 99%, 96%, and 67%, respectively. The sensitivity and specificity of 100-Hz, 5-s tetanus as an indicator of TOF ratios of 0.85 and 0.9 are 100% and 75%, 54% and 67%, respectively. We conclude that RF100 Hz visual assessment seems to be highly sensitive in evaluating residual paralysis, as the absence of RF100 Hz visual fading at the AP is compatible with a TOF ratio > 0.85.

IMPLICATIONS

After the administration of muscle relaxants, the absence of visual fading at the adductor pollicis, elicited in anesthetized patients by 100-Hz, 5-s tetanus, is compatible with a train-of four ratio > 0.85. Therefore, clinical observation of fading after 100-Hz, 5-s tetanus seems to be a highly sensitive test in evaluating residual paralysis.

Emergence from target-controlled anesthesia with propofol and sufentanil in patients undergoing intracranial surgery

The study was designed to characterise the emergence from target-controlled anesthesia assessed by the recovery of spontaneous breathing, eye opening to command, and extubation in 18 adult patients undergoing intracranial surgery. Total intravenous anesthesia was induced and maintained with propofol and sufentanil. Target plasma concentration of propofol ranged between 3.0 and 5.5 micrograms.ml-1 and infusion was stopped after head dressing. The initial target plasma sufentanil concentration of 0.50 ng.ml-1 was decreased to 0.15 ng.ml-1 after craniotomy; sufentanil infusion was discontinued at the dura closure. The time from the end of surgery (head dressing) to recovery of spontaneous breathing was 8.3 +/- 6.5 min, and the time to eye opening and extubation was 14.7 +/- 10.0 min. At the end of surgery, the calculated plasma propofol concentration was 3.42 +/- 0.26 micrograms.ml-1. It significantly decreased to 2.11 +/- 0.51 micrograms.ml-1 at recovery of spontaneous breathing and to 1.81 +/- 0.41 micrograms.ml-1 at eye opening and extubation. The calculated plasma sufentanil concentration was 0.108 +/- 0.019 ng.ml-1 at the end of surgery but did not change significantly between recovery of spontaneous breathing (0.089 +/- 0.013 ng.ml-1), eye opening and extubation (0.087 +/- 0.013 ng.ml-1). The calculated plasma propofol concentrations recorded at emergence were not correlated with patient age, total dose of propofol, and duration of infusion; corresponding calculated sufentanil concentrations were not correlated with age and total dose of sufentanil. An inverse relationship (p < 0.05) was found between the duration of sufentanil infusion and the calculated sufentanil concentrations at emergence. No correlation was observed between calculated concentrations of propofol and sufentanil at emergence.

Effects of target-controlled anesthesia with propofol and sufentanil on the hemodynamic response to Mayfield head holder application

The effects of target-controlled anesthesia with propofol and sufentanil on the hemodynamic response to Mayfield head holder (MH) application were evaluated in 18 ASA I and II patients undergoing scheduled intracranial surgery. Premedication consisted of hydroxyzine, alprazolam and atropine given orally 1 h before surgery. Anesthesia was provided with propofol and sufentanil using a target-controlled infusion device; constant calculated plasma concentrations of 4 micrograms ml-1 propofol and 0.5 ng ml-1 sufentanil were maintained throughout the study. Muscle relaxation was obtained with atracurium and ventilation was controlled with air/oxygen. The MH was fixed 45 +/- 12 min (mean +/- SD) after induction of anesthesia. Heart rate and systolic, diastolic, and mean non invasive arterial pressure were monitored and recorded 5 min before induction of anesthesia (control), 1 min before MH application (MH-1), at MH application, and 1 and 2 min after MH application. Systolic, diastolic, mean arterial pressure, and heart rate increased significantly during and after MH application when compared with MH-1 values, but remained constantly lower than control. Hemodynamic parameters measured 1 min before MH application were significantly lower than control. The results of the study indicate that target-controlled anesthesia maintained with constant calculated plasma concentrations of 4 micrograms ml-1 propofol and 0.5 ng ml-1 sufentanil prevents the increase in arterial pressure and heart rate beyond control values following MH application but may induce some degree of arterial hypotension in the absence of nociceptive stimulation.

Predictive accuracy of continuous propofol infusions in neurosurgical patients: comparison of pharmacokinetic models

The performance of 10 pharmacokinetic models in predicting blood propofol concentrations was evaluated in patients during neurosurgical anesthesia. Eight patients-ASA category I or II, aged 49 +/- 18-years, weighing 71 +/- 20 kg, and scheduled for routine neurosurgery-were anesthetized with propofol and sufentanil using Ohmeda pumps controlled with a personal computer. Sufentanil was administered as a bolus of 0.3 microgram.kg-1, 5 min before induction of anesthesia, and infused at a constant rate of 0.5 microgram.kg-1.h-1 throughout the study. At induction, propofol was administered as a bolus of 1.5 mg.kg-1 followed by a continuous infusion of 6 mg.kg-1.h-1. During surgery, the propofol infusion rate was deliberately increased by 2 mg.kg-1.h-1 every 15 min up to 12 mg.kg-1.h-1. Arterial blood samples were drawn at the end of each infusion step for measurement of propofol concentrations by high-performance liquid chromatography. Measured propofol concentrations were compared with theoretical concentrations derived from 10 published pharmacokinetic models designed in different clinical settings. Each model has been assessed by calculating the median of the performance error, the median of the absolute performance error, and their 10th and 90th percentiles. Models designed for certain categories, such as children, young, or elderly patients who received propofol as a bolus injection, showed a bad predictive accuracy. The models of Gepts et al. (Anesth Analg 1987; 66:1256-1263, Anaesthesia 1988; 43(suppl):8-13), Tackley et al. (Br J Anaesth 1989;62:46-53), and Cockshott (Postgrad Med J 1985;61:55), derived from healthy patients receiving continuous propofol infusions, provided the best agreement between expected and measured propofol concentrations; they showed bias and inaccuracy lower than 17%. In conclusion, the accurate prediction of blood propofol concentrations from different continuous infusion rates in ASA I or II patients requires the selection of appropriate pharmacokinetic models derived from similar categories of patients and using a similar technique of propofol administration. However, in clinical practice, the selection of a specific set among the appropriate models is balanced by the interindividual variability in blood propofol concentrations adjusted to clinical effects.

Administration of propofol by target-controlled infusion in patients undergoing coronary artery surgery

OBJECTIVES

To study the predictive performance of a target-controlled infusion (TCI) system of propofol in patients undergoing coronary bypass graft (CABG) surgery, using a referenced pharmacokinetic set derived from healthy patients. Also, to determine the propofol concentrations required for clinically acceptable induction and maintenance of anesthesia when combined with midazolam as premedication and a continuous alfentanil infusion and to study the hemodynamic stability of this technique.

DESIGN

Prospective noncomparative study analysis.

SETTING

Operating room at a university hospital.

PARTICIPANTS

Twenty-on patients with good left ventricular function undergoing coronary artery surgery.

INTERVENTIONS

Patients were anesthetized using a continuous infusion of alfentanil (mean infusion rate: 1 microgram/kg/min) and propofol administered by TCI.

MEASUREMENTS AND MAIN RESULTS

The predictive performance of the TCI system (212 arterial samples) was measured at specified time points before, during, and after bypass. The TCI system underestimated the measured blood propofol concentrations with a bias of +21.2% and +9.6% during the prebypass and the bypass periods, respectively. The predictive inaccuracy, expressed by the median absolute prediction error, was 23% and 18.5%, respectively. Mean target propofol concentrations required to induce and maintain anesthesia before bypass were 0.92 microgram/mL and 3.64 micrograms/mL, respectively. In the period during and after bypass, the mean target concentrations required to maintain anesthesia was 2.22 micrograms/mL. The administration of propofol by TCI was still associated with some short episodes of hemodynamic instability that were easily controlled by adjusting the target concentration in the majority of the patients. Therefore, the overall quality and ease of control of anesthesia were considered as being good or adequate.

CONCLUSIONS

In this group of patients undergoing CABG surgery, the TCI system used underestimated the measured propofol concentrations. However, the predictive performance of the selected mean pharmacokinetic parameters derived from healthy patients was acceptable during the whole surgical procedure.

Brain oedema induced by ventricular puncture. A study by magnetic resonance on a series of forty-one normal-pressure hydrocephalic patients

After ventricular catheterization magnetic resonance (MR) imaging very often demonstrates a focal area of high signal along the drain track which corresponds to parenchymal oedema. This high signal seemed to be more pronounced when the frontal area was catheterized than when the junctional parieto-temporo-occipital parenchyma (or trigonal area) was catheterized. In order to confirm this impression, we prospectively studied 41 consecutive patients with normal-pressure hydrocephalus in whom both of these brain regions were catheterized for intracranial pressure monitoring. Each patient was evaluated by serial MR. The extent of the MR hypersignal induced by both catheterizations was computed from digitized MR masks. The extent of the MR high signal area was significantly greater when the frontal area was catheterized compared to the trigonal area suggesting that the frontal area could be more prone to injury.

Cognitive recovery in idiopathic normal pressure hydrocephalus: a prospective study

Idiopathic normal-pressure hydrocephalus remains difficult to treat. Controversy exists as to whether or not shunting can really improve cognitive functions and whether quantified intracranial pressure monitoring (ICP-Mo) can predict postoperative improvement rates. Several studies have drawn attention to the lack of a prospective study concerning the surgical outcome of this condition. We have performed such a study on idiopathic normal-pressure hydrocephalus patients shunted on the basis of ICP-Mo when "high" waves (amplitude > 9 mm Hg) were present. Twenty-three patients underwent surgery. The preoperative and postoperative clinical states were assessed by a quantitative procedure blind to the ICP-Mo results. A clear postshunting improvement was seen in 96% of the patients at 1 year with a statistically significant correlation between high wave relative frequency and the grade of improvement (P < 0.05). At the same time, 66.6% of shunted patients showed a significant improvement in cognitive functions. Complications of shunting were successfully managed without residual deficits in this series. We recommend the use of quantitative ICP-Mo as a criterion for surgery and to predict the improvement grade.

Predictive accuracy of midazolam in adult patients scheduled for coronary surgery

STUDY OBJECTIVE

To evaluate the predictive accuracy of midazolam during cardiac anesthesia so as to orient the selection of the most appropriate pharmacokinetic model for use in a computer-assisted continuous-infusion system.

DESIGN

Retrospective analysis.

SETTING

Operating room at a university hospital.

PATIENTS

66 consecutive middle-aged and elderly coronary patients scheduled for coronary artery bypass graft (CABG) surgery.

INTERVENTIONS

Patients were anesthetized using a variable-rate infusion of alfentanil combined with midazolam in an attempt to achieve and maintain target concentrations of 100 ng/ml or 500 ng/ml.

MEASUREMENTS AND MAIN RESULTS

A total of 323 arterial blood samples were taken, and serum midazolam concentrations were measured by high-performance liquid chromatography. Predicted midazolam concentrations were calculated using 3 selected data sets. Their bias, inaccuracy, and dispersion were assessed by determining the median performance error, the median absolute performance error (MDAPE), and the 10th and 90th percentiles. Two of the selected data sets of midazolam, with a clearance lower than 5 ml/kg/min, were very accurate (MDAPE less than 20%) in predicting low or high prebypass concentrations of midazolam in adult patients with good left ventricular function.

CONCLUSIONS

Two of the 3 pharmacokinetic data sets of midazolam studied may be selected when using a computer-assisted infusion system in adult coronary patients.

Predictive accuracy of alfentanil infusion in coronary artery surgery: a prebypass study in middle-aged and elderly patients

Twenty-three informed and consenting patients scheduled for CABG were anesthetized using computer-controlled infusions of alfentanil, midazolam, and pancuronium. Thirteen middle-aged patients received a preprogrammed infusion scheme of alfentanil, simulated using the population pharmacokinetic set of Maitre et al (Group M), and 10 elderly patients received a preprogrammed infusion scheme simulated using the model of Helmers et al (Group H). The target alfentanil concentrations in groups M and H for tracheal intubation were: 300-500 ng/mL and for sternotomy: 500-700 ng/mL. Blood alfentanil concentrations were measured at tracheal intubation, skin incision, sternotomy, and aortic cannulation. The bias, inaccuracy, and precision of each pharmacokinetic set were assessed by the median performance error (MDPE), the median absolute performance error (MDAPE), and the 10th and 90th percentiles of the performance errors (P10, P90), respectively. The predictive accuracy of seven other alfentanil pharmacokinetic sets selected from the literature was also evaluated retrospectively. The measured alfentanil concentrations were underpredicted when using all the pharmacokinetic sets, except the set of Scott et al (MDPE: -15.9%). The sets of Maitre et al and Helmers et al were found not to be accurate (MDAPE > 40%) in both groups M and H. The set of Scott et al with the lowest clearance (2.4 mL/kg/min) shows the best accuracy (MDAPE: 19.5%) and precision (P10: -40%, P90: 16%). In conclusion, the set of Scott et al should preferably be selected to predict prebypass alfentanil infusion accurately in either middle aged or elderly patients who have normal myocardial function (LVEF > 50%) and are scheduled for CABG.

Predictive accuracy of continuous alfentanil infusion in volunteers: variability of different pharmacokinetic sets

To evaluate the variability of the predictive accuracy of alfentanil by using different pharmacokinetic data sets, eight healthy young male adult volunteers were given the same alfentanil infusion for 4 h. Nineteen venous blood samples were taken from each volunteer, and alfentanil concentrations were titrated by radioimmunoassay. For each volunteer, the pharmacokinetic variables of a two-compartment model were calculated, averaged, and considered as a reference set. Based on the infusion profile given to the volunteers, central compartment concentrations were calculated by using the reference set and nine previously published pharmacokinetic sets of alfentanil concentrations in healthy adults. The bias, inaccuracy, and dispersion of each data set were assessed by determining the median performance error, the median absolute performance error (MDAPE) and the 10th and 90th percentiles, respectively. By using the pharmacokinetic variables of the volunteers, the predictive accuracy was excellent (MDAPE, 7.25%). Among the 10 averaged pharmacokinetic sets, there was a significant correlation between their bias and clearance (R2 = 0.996). The reference set had the best predictive accuracy (MDAPE, 23.6%). Five sets from the literature also showed a reliable predictive accuracy but four other sets with a clearance more than 5 mL.kg-1.min-1 and derived from a large bolus injection were inaccurate (MDAPE > 50%) as they underestimated the alfentanil concentrations. We conclude that pharmacokinetic sets derived from large bolus should not be selected to accurately predict alfentanil infusion.

A cadaveric study comparing discography, magnetic resonance imaging, histology, and mechanical behavior of the human lumbar disc

The aims of this study were 1) to compare discography and magnetic resonance imaging scanning on cadaver specimens and to correlate these imaging procedures by examining all the discs histologically; and 2) to study the extent to which the amplitude of rotational movement in the neutral and flexed position at a certain level correlates with the morphologic appearance of that disc. Twenty-four human lumbar spines were harvested from cadavers between the ages of 19 and 75 years. Each specimen underwent standard radiography, magnetic resonance imaging scanning, discography, histologic examination, and measurement of axial rotation in a torsion apparatus. For practical reasons, all specimens did not undergo all of the examinations. Not all peripheral anular lesions were detected by discography. Histology showed rim lesions of the anterior anulus in 18% of discs with normal discography. The overall incidence of anterior and posterior anular tears was greater in discs where larger amplitudes of rotation were observed. To which extent the one is a consequence of the other or vice versa is not clear. Magnetic resonance imaging was found to be less specific than discography. However, it must be emphasized that no axial magnetic resonance imaging scans were taken in this study. Discs with significantly decreased amounts of nuclear material (observed at histology) can still produce normal magnetic resonance imaging images. Infolding of the inner layers of the anulus fibrosus (33% anterior, 4% posterior) was a frequently observed feature.

CINA: a software to Compose INfusion sheets for i.v. Anesthetic drugs

CINA is a software which uses LOTUS 1-2-3 commands and macros and it runs on an IBM PC. It contains an extensive database of three sections. Section 1 includes a list of several models of commercialized infusion devices. Section 2 presents the available IV packagings for a list of IV drugs. Section 3 contains the record of IV standard infusion regimens for each drug. Any other new infusion device, drug, or standard infusion regimen can be added or modified. The software verifies the compatibility of the prescribed infusion device according to the available drug packaging contained in the database. Moreover, it converts the infusion steps into the flow-rate units of the selected infusion device according to the patient's weight and the chosen drug concentration. Finally, the software allows the storage of all the information on a disk file or outputting on a printer.

Tuberculosis in children: a 13-year follow up of 1714 patients in a Belgian home care centre

From May 1970 to September 1983, 1714 children with different forms of primary tuberculosis were referred to the paediatric home care centre (Enfants soignés au Foyer, E.S.F.) of the Brussels University Hospital St.-Pierre. They were subdivided in five groups: asymptomatic (33%), symptomatic (28%), dubious tuberculous infections (35%), high-risk contacts (3%) and unestablished diagnosis (1%). They were aged from 10 days to 19 years, and 82% of them were migrants of low socio-economic level. Fifty percent of the symptomatic infections, mainly pulmonary, appeared in children under 3 years of age. An adult source of contamination was identified in 33% of the cases (48% of the symptomatic children). Diagnosis was based on tuberculin screening with a 2IU intradermal test. Gastric aspirates yielded Mycobacterium tuberculosis in 15% of our patients, 11% of them showing resistance to one or more tuberculostatic drugs. Treatment was given to 1359 patients with excellent results. Therapy was shortened during the last 2 years of the study from 12 to 6 months for the asymptomatic patients and from 12 to 9 months for the symptomatic infections. Few complications were observed. Tuberculosis remains a serious cause of morbidity particularly in migrant children. Correct diagnosis and treatment of the disease is very important.

[Osteosynthesis of lesions of the proximal femur using dynamic screw plates. Multicenter study: 1871 cases]

A series of 1871 lesions of the upper end of the femur were treated in 32 hospitals in Belgium using a dynamic hip screw. Unstable pertrochanteric fractures were present in 34.4%. The remainder were intracapsular, extracapsular and subtrochanteric fractures, or tumour deposits. The patients were elderly, infirm and usually female. A fortnight after operation 89% were sitting, 64% could walk with a frame and 31% with crutches. Failure of fixation occurred in 3.6% of cases overall, with 6.6% in unstable fractures. Perioperative screw compression did not appear helpful, since most fractures settled after operation.

Placental growth hormone as a potential regulator of maternal IGF-I during human pregnancy

Ninety-three healthy women were investigated during normal pregnancy, and 177 blood samples were obtained at various gestational stages. In 8 of the women, serial measurements were obtained over a period of 16-34 wk from 8 to 40 wk of gestation. In 13 women, daily blood samples were obtained from day 0 to day 6 after delivery. Insulin-like growth factor I (IGF-I) and human placental lactogen (hPL) were measured by radioimmunoassays. Growth hormone (GH) was estimated by two monoclonal antibody-based radioimmunoassays insensitive to physiological concentrations of hPL: the K24 assay, which recognizes only pituitary hGH, and the 5B4 assay, which reacts with all the known pituitary as well as placental GH variants. Placental GH was distinguished from the main pituitary variant through its specific immunoreactivity pattern. Mean plasma levels of IGF-I were relatively stable until 29-30 wk gestation, then increased progressively to reach a maximum at 35-36 wk. Regardless of gestational age, individual IGF-I values exhibited a highly significant positive correlation with placental GH, reflected by 5B4 immunoreactivity, whereas the correlation between IGF-I and hPL was not statistically significant. Considering each 2-wk gestational period separately, we found a positive correlation between IGF-I and 5B4 hGH at 31-32 wk. Conversely, no evidence of correlation was found between IGF-I and hPL at any period. After delivery, IGF-I evolution exhibited a biphasic pattern, with an initial decrease to low values followed by a progressive return toward levels found in nonpregnant healthy women. These results strengthen our previous hypothesis that placental growth hormone is involved in the control mechanism of serum IGF-I levels in normal pregnant women.

The pharmacokinetics of intravenous anaesthetic drugs given by infusion: SPINA--a software program

SPINA is a program developed with LOTUS 1-2-3 that simulates the pharmacokinetics of an infusion of intravenous anaesthetic drugs. SPINA incorporates a database which contains records of multiple-compartment pharmacokinetic models. The models have been obtained from the literature. They are directed towards those intravenous drugs that are used frequently during daily clinical anaesthetic practice. The models are classified using keywords for selection criteria (age, biometry, pathology and indication). To perform the pharmacokinetic simulation, the anaesthetist has to choose a pharmacokinetic model in which the program determines the turn-over rates, and displays a sequence of infusion steps. On request, SPINA provides the graphs for the theoretical drug distribution and for the infusion rate required to maintain the target concentration. SPINA therefore allows one to simulate the administration of intravenous anaesthetic drugs and to optimize their delivery.

A system for computer-aided diagnosis

MEDICIS is an integrated environment for computer-aided diagnosis. It consists of two subsystems: a module used by the expert to build knowledge bases and a consultation module to exploit those bases. MEDICIS uses a framed representation of knowledge. The inference engine performs logical reasoning without recourse to certainty factors. This phase is followed by a multicriteria analysis.

Six-year results of a multimodality treatment strategy for locally advanced breast cancer

Between 1976 and 1982, 59 patients with locally advanced breast cancer were treated with preoperative supervoltage radiotherapy, adjuvant preoperative and postoperative hormonochemotherapy, and modified radical mastectomy. Systemic treatment, which was started simultaneously with radiotherapy, consisted of a combination of daily oral tamoxifen and a monthly alternation of Doxorubicin + vincristine and cyclophosphamide + methotrexate + 5-fluorouracil (CMF). One of each cycle was given preoperatively at half dosage and five of each were repeated postoperatively at full dosage. All patients became operable. Results of pathologic examination of the operative specimen, available in 51 patients, showed complete disappearance of tumor tissue in breast areas in eight patients, of which three still had positive axillary nodes. After a median follow-up time of 6 years locoregional failure was observed in 12 patients (20%) but in only three (5%) did it occur before distant failure. The actuarial median survival of the entire patient population is close to 4 years. Seven patients are alive without recurrence at greater than 9 years. This aggressive multidisciplinary treatment approach is associated with a projected 30% long-term survival (10 years), excellent local control, but substantial toxicity.

Administration of enoximone in cardiogenic shock

Thirteen patients in severe cardiogenic shock, persisting despite the use of adrenergic agents, were treated with enoximone, a recently available phosphodiesterase inhibitor. Cardiogenic shock was characterized by low cardiac output (less than 2.5 liter.min-1.m-2), elevated pulmonary artery balloon-occluded pressure (greater than or equal to 15 mm Hg), decreased urine output (less than 20 ml.hour-1) and increased blood lactate (greater than or equal to 2.0 mEq.liter-1). Ten patients were mechanically ventilated. A short-term intravenous infusion of 0.5 mg.kg-1 in 20 minutes of enoximone resulted in significant increases in cardiac index (from 1.8 +/- 0.3 to 2.9 +/- 0.3 liter.min-1.m-2, p less than 0.001) and stroke index (from 17.8 +/- 3.3 to 21.9 +/- 5.1 ml.m-2, p less than 0.001) and significant decrease in pulmonary artery balloon-occluded pressure (from 21.7 +/- 5.8 to 19.8 +/- 6.0 mm Hg, p less than 0.01) without a consistent change in mean arterial pressure (from 79 +/- 8 to 76 +/- 9 mm Hg, difference not significant). Enoximone administration decreased arterial oxygen tension (from 108 +/- 42 to 94 +/- 36 mm Hg, p less than 0.01) and increased venous admixture (from 12.8 +/- 6.5 to 16.0 +/- 8.0%, p less than 0.01). In 8 patients, a second infusion of 0.5 mg.kg-1 immediately thereafter amplified these changes. All patients but one survived the episode of cardiogenic shock and 5 patients left the hospital alive. These results indicate that the addition of enoximone to adrenergic agents in the treatment of cardiogenic shock can markedly increase cardiac output and stroke volume without substantial effects on arterial pressure.

Amrinone administration in endotoxin shock

This study explored the hemodynamic effects of amrinone, a phosphodiesterase inhibitor, in association with intravenous fluids, in the treatment of endotoxin shock. Mongrel dogs were anesthetized with pentobarbital and mechanically ventilated with room air. Treatment was started 30 min after slow intravenous administration of 3 mg/kg of E. coli endotoxin. In the first part of the study, ten dogs were resuscitated for 30 min with intravenous saline alone (10 ml/kg) and for the next 3 h by saline (10 ml/kg/h) and amrinone 40 micrograms/kg/min. During this latter period, arterial pressure remained stable while cardiac output significantly increased from 3.1 +/- 0.5 to 5.2 +/- 0.7 l/min (P less than 0.01), and oxygen delivery increased from 616 +/- 92 to 983 +/- 156 ml/min (P less than 0.01). Comparison with control animals revealed that amrinone infusion prevented the decrease in left ventricular stroke work and markedly increased oxygen delivery. In the second part of the study, 18 dogs were treated by saline infusion titrated to maintain pulmonary artery balloon-occluded pressure at baseline level. In ten dogs, amrinone was added 60 min after endotoxin administration at a dose of 40 micrograms/kg/min. Total amount of fluids infused averaged 87 +/- 14 ml in the amrinone-treated dogs and 64 +/- 15 ml in the control dogs (differences nonsignificant). Oxygen delivery and oxygen consumption increased significantly in the amrinone-treated dogs (from 541 +/- 36 to 1063 +/- 176 ml/min, P less than 0.01, and from 145 +/- 23 to 202 +/- 38 ml/min, P less than 0.01, respectively) but not in the control dogs. The amrinone-treated dogs had lower PaO2 and higher venous admixture than the control dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

[Sequential development of vitamin D metabolites under isoniazid and rifampicin therapy]

A sequential study of 25-hydroxy vitamin D (25-OH-D), 1.25 dihydroxy vitamin D [1.25 (OH)2-D], PTH, alkaline phosphatase and gammaglutamyl transpeptidase (gamma GT) was undertaken in a series of 46 children with asymptomatic tuberculosis treated by isoniazid (INH) alone or associated with rifampin (RMP). These parameters were measured before treatment, 1 month, 3 months after the onset and at the end of treatment (6 months). In order to reduce the influence of the time of the year on the 25-OH-D levels, 22 patients were selected for whom the whole treatment took place between October and May of the following year. In this group, 13 children were treated by INH and RMP, 9 by INH alone. A statistically significant decrease in 25-OH-D levels could be demonstrated after 3 months of treatment in 13 patients under INH and RMP as well as a significant increase in alkaline phosphatase and gamma GT levels. In 9 patients given INH alone, 1.25 (OH)2-D levels decreased after 3 months without significant changes in 25-OH-D, alkaline phosphatase or gamma GT levels. These results emphasize the need for regular biochemical supervision, even if no sign of rickets is observed in these patients.

Comparison of different sandwich enzyme immunoassays for the quantitation of human apolipoproteins A-I and A-II

Variants of a non-competitive enzyme immunoassay for human apolipoproteins A-I and A-II are described. The method developed is highly sensitive and highly specific. There is a good correlation between the reference technique (electroimmunoassay) and both apolipoprotein A-I and A-II assays (r=0.92). For the apolipoprotein A-I assay, seven simple treatments were studied. Two of these treatments (plasma plus Tween 20 and serum plus apo A-II) greatly increased the precision and the accuracy of the results. For the apo A-II measurement, no treatment of the samples is necessary, but plasma should be preferentially used rather than serum.

Ultrasound: a method for kidney size monitoring in children

Normal kidneys were studied echographically in 170 children from 0-15 years of age. The length, thickness, width, volume and largest sagittal and transverse areas were measured and plotted against the children's height and body surface to establish standard growth curves. The usefulness of this non-invasive inter- and intra-individual estimation of renal size in following the progress of kidney alteration in children was illustrated in one case of malakoplakia and one case of parenchymal scars.

Placebo controlled pneumococcal immunization in patients with bronchogenic carcinoma

Pneumococcal vaccine [heptadecavalent types 1, 2, 3, 4, 6A, 7F, 8, 9N, 11A, 12F, 14, 15F, 17F, 18C, 19F, 23F and 25 pneumococcal capsular polysaccharide vaccine (Moniarix)] or placebo were evaluated in 26 and 21 patients with bronchogenic carcinoma, most of whom did not receive prior radiotherapy or chemotherapy. No difference was detected as far as clinical outcome is concerned: 3 vaccinated patients out of 26 (11.5%) developed pneumococcal infections (1 fatal bacteremia) and 4/21 (19%) of those who received a placebo presented such an infection (1 fatal bacteremia). The antibody response was significantly increased in the vaccines for types 1, 2, 7F, 8, 9N, 12F, 14, 17F, 18C, 23F and 25.

Modulation of immunoreactive somatomedin-C levels by sex steroids

Among 28 menstruating women tested once randomly during the cycle, somatomedin-C (Sm-C) values were lower in the 10 women in normal follicular phase than in the 10 women in normal luteal phase or the 8 women with hyperandrogenism. Among these 28 subjects, Sm-C showed a positive correlation with testosterone and a positive correlation of borderline significance with oestradiol. A positive correlation was also evidenced between Sm-C and in progesterone among the 20 women of this group who were not hyperandrogenic. In 5 other normal women investigated daily throughout an entire menstrual cycle, Sm-C concentrations were higher during days +4 to +9 of this cycle (luteal phase) than during days -3 to -8 (follicular phase). In another group of 21 healthy women, Sm-C values were increased during medroxyprogesterone acetate (150 mg trimestrially) treatment. In 7 normal men, Sm-C decreased during ethinyl-oestradiol (1 mg daily for 5 days) administration. These findings suggest that circulating Sm-C levels are modulated by variations of sex steroids which occur during the menstrual cycle as well as by pharmacological doses of oestrogens and progestagens.

Seasonal variation of platelet serotonin uptake and 3H-imipramine binding in normal and depressed subjects

Density of 3H-imipramine binding sites and serotonin (5-HT) uptake in blood platelets were repeatedly recorded in normal controls (n = 9) and depressed patients (n = 7 for the imipramine binding assay and n = 4 for the serotonin uptake) over a 1-year period. The study demonstrated a striking seasonal variation of both parameters in both groups, with lower values in winter and spring than in summer and fall. No difference in the density of 3H-imipramine binding sites was found between the two populations throughout the year, but serotonin uptake was significantly decreased in depressed patients in May and September. These results underscore the importance of studying controls and patients at the same time of the year.

Fetal cardiac dimensions: a potential tool for the diagnosis of congenital heart defects

This study proposes normal values for fetal heart dimensions. They include the transverse and longitudinal diameters of the heart, as well as an estimate of the cardiac volume. The resulting nomograms were useful in the diagnosis of various congenital anomalies, as is demonstrated in three case reports. Although the nomograms are not intended to compete with more elaborate techniques of investigation of the fetal heart, such as M-mode echocardiography or Doppler studies, they are much easier to use and could be used as a complementary method to identify possible fetal cardiac anomalies.

The diagnosis of fetal microcephaly

Of 16 fetuses in whom microcephaly was suspected, nine (56.2%) were affected with microcephaly, and seven (43.8%) were unaffected. Subsequently, nomograms with mean and SDs for biparietal diameter, occipitofrontal diameter, head perimeter: bdominal perimeter, biparietal diameter:femur length, and femur length:head perimeter we derived. With the use of the data from 27 sonograms of the 16 fetuses, different thresholds of abnormality were tested. Three standard deviations from the mean for biparietal diameter, occipitofrontal diameter, head perimeter, and femur length:head perimeter were sensitive thresholds for the diagnosis of fetal microcephaly with no false negative diagnoses. Four standard deviations from the mean for occipitofrontal diameter, head perimeter:abdominal perimeter, and femur length:head perimeter were specific tests with no false positive diagnoses. The use of multiple diagnostic tests was necessary to improve accuracy in the diagnosis of fetal microcephaly. Further clinical studies are needed to delineate more clearly optimal tests and thresholds of abnormality.

A longitudinal study of fetal weight growth

In a longitudinal study of fetal growth, the authors attempted to provide normal values for estimating fetal weights at various gestational ages.

The binocular distance: a new way to estimate fetal age

Fetal ocular biometry has been previously established and reported. The purpose of this communication is to report an equation to predict fetal age from the binocular distance. The error of the estimation is also reported. The potential value of this measurement is illustrated in a case of thanatophoric dysplasia.