Case Report: Atypical acute compartment syndrome of the forearm in a child following minor trauma with consecutive osteomyelitis.

Introduction: Forearm compartment syndrome (CS) in children is above all a clinical diagnosis whose main cause is traumatic. However, rarer causes such as infection can alter its clinical presentation. Clinical case: An 8-year-old boy has been seen in the emergency department complaining of severe forearm pain under a splint in a mild traumatic context. The previous radiological imaging examination three days before had not revealed any fractures. On admission, he presented with major signs of skin inflammation, loss of mobility, paresthesia and a significant biological inflammatory syndrome. The acute CS diagnosis has been made and was treated, but its atypical presentation raised a series of etiological hypotheses, in particular infectious, even if it remains rare. Complementary imaging examinations confirmed the presence of osteomyelitis of the distal radius as well as an occult Salter-Harris II fracture. Discussion: Beyond the classic "five P's of CS" -pain, paresthesia, paralysis, pallor and pulselessness-, CS's clinical presentations are multiple, especially in pediatric patients. In children, severe pain and increasing analgesic requirement must be indicators of a CS. We hypothesize that this patient sustained a nondisplaced Salter-Harris II fracture with a hematoma colonized by hematogenous osteomyelitis explaining its initial clinical presentation. Conclusion: Hematogenous osteomyelitis complicated by CS is rare and may be accompanied by a traumatic history. It's atypical presentation in pediatric patients requires vigilance and prompt diagnosis given the disastrous and irreversible complications.

Acute hemodynamic changes of pressure-controlled inverse ratio ventilation in the adult respiratory distress syndrome. A transesophageal echocardiographic and Doppler study.

Twelve patients with the adult respiratory distress syndrome were included in this study and evaluated by transesophageal echocardiography and Doppler, assessing right and left ventricular intracardiac blood flow alterations with progressive increase of inspiration-to-expiration (I-E) ratios. Whereas midpulmonary artery flow parameters did not show any change, early left ventricular filling demonstrated a significant increase after switching the ventilatory mode from volume to pressure-controlled ventilation with 2:1 I-E ratio (end-inspiration: 39 +/- 26 cm with positive end-expiratory pressure [PEEP]-ventilation to 68 +/- 56 cm with pressure-controlled inverse-ratio ventilation, 2:1; p < 0.01; at end-expiration, from 67 +/- 21 cm with PEEP-ventilation to 83 +/- 36 cm with pressure-controlled ventilation 1:1; p < or = 0.05), resulting probably from different ventilatory flow and pressure curves. In the meanwhile, cardiac index demonstrated a significant augmentation (from 4.73 +/- 1.71 L/min.m2 to 5.56 +/- 1.66 L/min.m2; p < 0.05). Pressure-controlled inverse ratio ventilation results in both respiratory and hemodynamic advantages as is demonstrated by this study.

Evaluation of transesophageal echocardiography as a diagnostic and therapeutic aid in a critical care setting.

OBJECTIVES: To assess the impact of transesophageal echocardiography (TEE) on therapeutic management in relation to pulmonary artery catheterization (PAC) in the ICU. DESIGN: Retrospective analysis of 108 consecutive TEE video and related patient files during a 7-month period. SETTING: A 33-bed medical and surgical ICU. METHODS: All critically ill patients with or without PAC in whom a TEE was performed, excluding postoperative cardiac surgical patients. Patients were divided in a cardiac and a septic group depending on the primary disease on admission to the ICU. The impact of TEE in relation to PAC on ICU management was evaluated in whether therapy changes were performed strictly on the basis of the TEE findings. MAIN RESULTS: Of 64% of patients with a PAC, 44% underwent therapy changes after TEE: 41% in the cardiac and 54% in the septic subgroup. In 41% of patients without a PAC, TEE led to a change in therapy. CONCLUSIONS: TEE results in altered therapeutic management in at least one third of our (noncardiac surgery) ICU patient population independent of the presence of a PAC.

Cardiac output-changes during hemodialysis with ultrafiltration.

Cardiovascular hemodynamics were studied noninvasively before, during and after hemodialysis with ultrafiltration in 18 patients on chronic hemodialysis. The cardiac output (CO) was determined by a continuous wave Doppler method. Overall, no major CO changes were seen (7.8 +/- 0.6 l/min post- versus 7.4 +/- 0.5 l/min pre-dialysis). Mean blood pressure rose slightly but significantly from 103 +/- 4 mmHg before to 113 +/- 3 mmHg after hemodialysis (p less than 0.01). Important interindividual differences in the intradialytic evolution of CO were observed. In patients with previous myocardial infarction or dilated cardiomyopathy (n = 12), CO rose significantly from 7.3 +/- 0.7 l/min before to 8.4 +/- 0.6 l/min after hemodialysis (p less than 0.05), while in patients without manifest myocardial disease (n = 6) CO decreased from 7.5 +/- 0.7 l/min to 6.6 +/- 0.9 l/min (NS). Comparison of the evolution of CO in both groups by variance analysis revealed a significant difference (p less than 0.01). It is concluded that, in response to hemodialysis with ultrafiltration, CO probably will increase in patients with myocardial infarction or congestive cardiomyopathy, but probably will decrease in patients without.

Peripheral vascular effects of calcium entry blockers in normal volunteers.

The peripheral vascular effects of calcium entry blockers have been scarcely investigated. Therefore we examined the effects of different doses of tiapamil and nifedipine in two groups of volunteers. The measurements were done by plethysmography. At a lower dose there is a significant increase in venous capacity. At a higher dosage there is an increase of the arterial flow, eliciting a reflex sympathetic stimulation with heart rate increase and venoconstriction. Therefore calcium entry blockers can be considered as arterial and venodilators.

Influence of chest physiotherapy on arterial oxygen saturation.

Two groups of ventilated patients were compared for chest physical therapy on an ICU: respiratory insufficient patients on one side and a control population on the other were submitted either to percussion or vibration therapy, and to postural drainage. Our data show a decrease in arterial oxygen saturation after CPT and after 2h monitoring; the lateral position results in a better SaO2 in the pneumonia group while SaO2 tend to decrease in the control population. However, no significant therapeutic influence of vibration nor percussion was found. Our data suggest CPT does not result in a short term respiratory benefit. Further investigations with prolonged sessions of postural drainage are required.

The initial clinical evaluation of a transesophageal system with pulsed Doppler, continuous wave Doppler, and color flow imaging based on an annular array technology.

The application of transesophageal echocardiography (TEE) offers access to a great deal of important clinical information regarding cardiovascular anatomy and physiology. Two applications which have not been reported and would appear to be of interest are continuous wave Doppler capabilities and the implementation of higher frequency transducers. A TEE system designed at the Institute of Biomedical Engineering in Trondheim, which is based on an annular array technology, offers these capabilities. We evaluated this instrument in the clinical setting in a series of 30 patients to test the probe function in terms of the tissue and flow imaging quality with a 7.5 MHz carrier frequency, and to report on the implementation of a continuous wave Doppler modality in a TEE probe. We found that the annular array method permitted the use of high frequency probes for tissue and flow imaging which resulted in excellent image resolution, and that shifting the carrier frequency of the transducer to a lower frequency permitted the optimization of the Doppler sensitivity. The continuous wave Doppler was used to measure abnormal blood flow velocities in excess of 5.0 m/s, and was particularly useful in the operating room as velocity measurements could be obtained without compromising the sterile field. The results of our evaluation indicate that high imaging frequencies and continuous wave Doppler can be applied by an annular array TEE transducer.

Production of carrier-free 66Ga and labeling of antimyosin antibody for positron imaging of acute myocardial infarction.

A method for labeling monoclonal antimyosin antibodies with 66Ga is described. The radionuclide is a positron emitter (t1/2: 9.4h) produced by means of the 63Cu (4He, n) 66Ga reaction. Purification of the 66Ga from the copper target is described in detail. Monoclonal antimyosin antibodies are labeled with 66Ga at a high yield (99%) by transcomplexation from an acetate buffer with the diethylenetriamine pentaacetic acid (DTPA)-labeled antibody and preliminary evaluated in two dogs for imaging of myocardial necrosis by positron emission tomography.

Doppler evaluation of right ventricular outflow impedance during positive-pressure ventilation.

Positive-pressure ventilation has often been advocated to increase oxygen delivery. This ventilation mode itself, however, can impair right ventricular ejection and, thus, diminish cardiac output. In this study, alterations of right ventricular outflow impedance were evaluated after stepwise increases of positive end-expiratory pressure (PEEP). Different pulmonary artery flow characteristics were evaluated with transesophageal echocardiography in mechanically ventilated postoperative coronary artery bypass surgery patients without pulmonary hypertension. A progressive decrease of pulmonary artery flow velocity and time velocity integrals was found with increasing PEEP levels. No changes in acceleration time or pre-ejection period were observed. In order to decrease the influence of heart rate, the ratios of the different pulmonary artery flow characteristics were calculated. At end-inspiration, both the ratio of acceleration time to right ventricular ejection period and the ratio of pre-ejection period to right ventricular ejection period showed progressive increases above 10 cmH2O positive end-expiratory pressure (13.3% at the level of 15 cmH2O and 8.5% at the level of 20 cmH2O). In this study, acceleration time appears not to be of importance in ventilated patients. These data strongly support the hypothesis that intermittent squeezing of the pulmonary arterial tree during inspiration, rather than positive end-expiratory pressure, creates an increase of right ventricular outflow impedance.

Transesophageal Echo-doppler evaluation of the hemodynamic effects of positive-pressure ventilation after coronary artery surgery.

Transesophageal echocardiography was used to extend knowledge about the impact of positive end-expiratory pressure (PEEP) during mechanical ventilation on right and left ventricular function and right ventricular impedance. At 20 cmH2O PEEP, a progressive increase of right ventricular end-diastolic area was seen (27%) that coincided with a reduction of early left ventricular filling velocity (25%) across the mitral valve, and a decrease of both pulmonary artery flow velocity (end-expiration 27% and end-inspiration 42%) and time-velocity index (end-inspiration 25%). As these changes were not accompanied by a change of the fractional area of contraction, the increase of the right ventricular diameter might be explained by right ventricular compensation due to an imbalance between augmented right ventricular impedance and reduced venous return.