Biomedical subjects

M Saada

Publications and source records attributed to M Saada.

At least 37 records · Page 2Linked to original sources

PubMed1991

Intraoperative transesophageal echocardiography for pulmonary embolectomy without cardiopulmonary bypass.

This case report describes a patient with massive pulmonary embolism and acute circulatory failure in whom transesophageal echocardiography permitted the diagnosis of thrombi in the main pulmonary truncus and in the right branch and guided intraoperatively the surgical embolectomy performed under simple venous inflow occlusion because of a contraindication to heparin administration. Transesophageal echocardiography seems to be a very helpful technique to diagnose promptly massive pulmonary embolism and a very useful tool at the time of operation to guide the embolectomy.

Cardiopulmonary Bypass↗

PubMed1991

Effects of clonidine on variation of arterial blood pressure and heart rate during carotid artery surgery.

The effect of oral premedication with 300 micrograms of clonidine on systemic arterial pressure, heart rate, and plasma norepinephrine levels was assessed in a double-blinded, placebo-controlled study conducted in 29 patients subjected to carotid artery surgery (CAS). Anesthesia was induced with thiopental, 6 mg/kg, and alfentanil, 0.05 mg/kg, and maintained with alfentanil and 0.6% isoflurane in 50% N20/O2. The study was divided into five periods as follows: (1) anesthesia to start of surgery; (2) surgery to carotid artery clamping; (3) carotid artery clamping to unclamping; (4) carotid artery unclamping to the end of surgery; and (5) the first 4 postoperative hours in the recovery room. In the clonidine group (n = 14), plasma norepinephrine concentrations were significantly lower before induction of anesthesia and during the operative period. Heart rate and systemic arterial pressure were lower (P less than 0.01) in the clonidine group at 3 different time intervals (control, carotid clamping, carotid unclamping). However, during each of the previously defined periods, the variability of heart rate and systemic arterial pressure, assessed by the coefficient of variation, was not different between the two groups. The lability of these hemodynamic parameters, expressed as the percentage of values, which increased or decreased more than 20% of control values during the corresponding period, was also comparable between the two groups. The number of patients who experienced at least one episode of hypertension (systolic arterial pressure greater than 180 mm Hg), hypotension (systolic arterial pressure less than 100 mm Hg), or bradycardia less than 45 beats/min was not different between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed1991

[Analysis of failures of spinal anesthesia as a function of practice development in a university hospital].

This study is a retrospective analysis of 303 consecutive spinal anaesthesia performed in orthopaedic patients of a University Hospital between January and December 1990. Failure of spinal anaesthesia was defined as the requirement for general anaesthesia to perform surgery. The parameters studied as possible risk factors of failure were patients demographics, local anaesthetic agents and solutions and techniques of spinal anaesthesia (single injection versus continuous spinal anaesthesia). Failures were related to inadequate or incomplete extension of sensory blockade or to difficulties to perform spinal injection. Continuous spinal anaesthesia was performed in 209 patients mostly with 0.5% isobaric bupivacaine, while 94 patients received a single injection of either hyperbaric 0.5% tetracaine with adrenaline or 0.5% bupivacaine or 5% lidocaine. Failures occurred in 6.3% of the cases but were significantly less frequent with continuous spinal anaesthesia (4.8%) than with the conventional technique (9.6%). The incidence of failure was higher with hyperbaric tetracaine (11.1%) confirming its poor reliability. Inadequate extension of the anaesthetic block was the main cause of failure whatever the spinal anaesthetic technique. These results point out the reliability of continuous spinal anaesthesia but problems may occasionally occur due to spinal catheter misplacement.

Academic Medical Centers↗

PubMed1991

Effect of epidural clonidine on analgesia and pharmacokinetics of epidural fentanyl in postoperative patients.

Epidural clonidine produces postoperative analgesia in patients and potentiates opioid analgesia in animals. The aim of the current study was to assess the effect of epidural clonidine on the plasma concentrations and analgesic effect of fentanyl after epidural administration. Twenty ASA physical status 2 or 3 patients recovering from abdominal surgery were allocated randomly to receive either epidural fentanyl (100 micrograms in 10 ml isotonic saline; EF group) or epidural fentanyl (same dose) plus epidural clonidine (150 micrograms; EF + C group) in isotonic saline solution. Analgesia was assessed over a period of 12 h after epidural injection. Venous samples were obtained until 360 min after epidural injection for radioimmunoassay determination of plasma fentanyl concentration. Onset of analgesia was similar in the two groups of patients (13 +/- 6 and 13 +/- 3 min, respectively, after injection), but duration was more than doubled in the patients receiving clonidine (543 +/- 183 vs. 250 +/- 64 min). Peak plasma fentanyl concentrations (Fmax) and the time to reach Cmax (Tmax) were comparable in the two groups (0.29 +/- 0.15 ng.ml-1 at 16.2 +/- 14.8 min in the EF group and 0.27 +/- 0.11 ng.ml-1 at 8.3 +/- 5.5 min in the EF + C group), as were plasma concentrations at each definite time of measurement. Drowsiness and hypotension were noticed in the EF + C group. Thus, epidural clonidine appears to prolong epidural fentanyl analgesia without affecting its plasma concentration.

Aged↗

PubMed1990

[Comparison between conventional and continuous spinal anesthesia using bupivacaine].

A study was carried out to find out whether dividing the dose of local anaesthetic would give a better control of the spread and duration of sensory blockade due to spinal anaesthesia. It was carried out in 34 patients (mean age 62 years) scheduled for elective limb vascular surgery. All were classed ASA 2 or 3. Sensory blockade was assessed using a fine needle, and the degree of motor blockade with Bromage's scale. This was carried out every 5 min for the first 30 min, and thereafter, every 15 min until recovery from anaesthesia was complete. In the first group of patients (n = 16), spinal anaesthesia was obtained with a 26 gauge needle, the patient lying on his side; 4 ml of 0.5% bupivacaine were injected (1 ml every 10 seconds) before putting the patient supine. In the second group (n = 18), the catheter for continuous spinal anaesthesia was set up with the patient in the same position as for the first group. Once a length of 1 cm had been introduced in the subarachnoid space, the patient was placed supine and 2 ml of 0.5% bupivacaine were injected. If 15 min later sensory blockade did not reach T10, further 0.5 ml aliquots were given every 10 min so as to obtain a level of sensory blockade between T9 and T11. Maximum extension of sensory blockade was 15.1 +/- 2.3 metamers in group 1, with an extension to T3 in 2 patients. In group 2, 12.9 +/- 3.1 mg bupivacaine anaesthetized 14.2 +/- 1.9 metamers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

[Diagnosis of severe pulmonary embolism by transesophageal echocardiography].

A 56-year-old woman was admitted to the Emergency Department for profuse diarrhoea, associated with hypokaliemia and dehydration. A subclavian venous catheter was inserted after she had a cardiac arrest. Six days later, the subclavian and innominate veins were thrombosed. Prophylactic low molecular weight heparin was then replaced by sodium heparinate. The patient's platelet count decreased to 65 G.1-1. It was nevertheless decided to remove her villous tumour. After the operation, the patient became shocked, with worsening thrombocytopaenia (15 G.1-1). She was unresponsive to fluid replacement. Transoesophageal echocardiography (TEE) was carried out, as pulmonary arterial catheterization was considered too dangerous. A "white" thromboembolus was discovered in the right pulmonary artery. Embolectomy was successfully performed without extracorporeal circulation. Flow was completely restored in the main pulmonary artery, but only partially in the right branch. Oral anticoagulation was started postoperatively. It is concluded that TEE might be a very helpful technique to promptly diagnose acute pulmonary embolism; moreover, it could be an alternative to pulmonary angiography, especially in patients in a poor state.

Drug Hypersensitivity↗

PubMed1990

[Opening of a foramen ovale during liver transplantation. The value of transesophageal echocardiography].

A case is reported of a foramen ovale becoming patent during orthotopic liver transplantation (OLT). The patient had a hepatoma secondary to post-hepatitis cirrhosis. Monitoring included transesophageal echocardiography (TEE). A veno-venous shunt between the right femoral, portal and left axillary veins was used so as to maintain the venous return during portal and caval clamping. The patient's haemodynamic state remained quite stable throughout this period, and no vasoactive drug was required. Five min after graft reperfusion, pulmonary arterial pressure increased suddenly (mean PAP: 27 mmHg). TEE revealed paradoxical movements of the atrial septum. Colour coded Doppler ultrasound showed blood flowing from the right to the left atrium through a patent foramen ovale. Fifteen min later, mean PAP decreased (18 mmHg) and TEE no longer showed any flow between the two atria. Several studies have reported transient pulmonary hypertension after unclamping when the donor liver is reperfused. This could induce right ventricular failure, with transient inversion of the atrial pressure gradient, which, in turn, could result in a right-to-left shunt through a patent foramen ovale. TEE can monitor regional and overall left ventricular function as well as the atrial septum. This technique might therefore to be useful for cardiac monitoring during OLT.

Cardiomyopathies↗

PubMed1990

Clonidine-induced analgesia in postoperative patients: epidural versus intramuscular administration.

To compare the analgesic efficacy and plasma concentration of intramuscular (IM) versus epidural (EP) clonidine, 20 patients recovering from orthopedic or perineal surgery were randomly divided into two groups of ten. Clonidine (2 micrograms/kg) was administered epidurally in group 1 and intramuscularly in group 2. Analgesia was assessed using a visual analog scale (VAS) over a period of 6 h following clonidine administration. Venous blood samples were obtained at specific intervals for radioimmunoassay determination of plasma clonidine concentrations. The maximum reduction in VAS pain score was 78.5 +/- 20.6% in the EP group and 68.1 +/- 31.5% in the IM group (NS). Onset of analgesia was similar (within 15 min of injection), but duration tended to be longer after epidural than intramuscular administration (208 +/- 87 min vs. 168 +/- 95 min, mean +/- SD, P greater than 0.05). The peak plasma clonidine concentration after EP injection was 0.82 +/- 0.22 ng/ml and 1.02 +/- 0.76 ng/ml after IM injection. Hypotension, bradycardia, and drowsiness occurred with both methods of administration. None of these effects required treatment. Thus, in postoperative patients clonidine produces similar analgesia and side effects after parenteral or EP administration.

Adult↗

PubMed1989

Baroreceptor control after cervical epidural anesthesia in patients undergoing carotid artery surgery.

Baroreceptor (BR) reactivity was studied in 16 patients scheduled for carotid artery surgery performed under cervical epidural anesthesia with 0.375% bupivacaine (15 mL). In the first seven patients, BR reactivity was assessed by measurement of the slopes of the linear relationship between systolic arterial pressure (SAP) and the RR interval on the electrocardiogram. Alterations of blood pressure (BP) were produced using sequential intravenous (IV) doses of nitroglycerin (NTG; 100 to 200 micrograms) or phenylephrine (PHE; 100 to 200 micrograms), before and 30 minutes after epidural anesthesia. The changes in SAP and heart rate (HR) determined during the four phases of a Valsalva maneuver were evaluated in a second set of measurements before and after cervical epidural blockade. In nine additional patients, a third set of measurements studying BR reactivity after carotid clamping and unclamping was performed in order to assess the effect of carotid handling on BP control. Cervical epidural anesthesia induced moderate decreases in BP (SAP, 150 +/- 18 mmHg before cervical block, 143 +/- 27 mmHg after cervical block, P less than 0.05) and HR (RR, 812 +/- 120 ms before cervical block, 938 +/- 130 ms after cervical block, P less than 0.05). Cervical epidural anesthesia depressed BR reactivity during deactivation as assessed by the decrease in the BR slope after PHE injection (6.6 +/- 4.4 ms/mmHg before cervical block v 2.5 +/- 1.8 ms/mmHg after cervical block, P less than 0.01) and activation as assessed by the changes in SAP and HR during phases II and IV of the Valsalva maneuver.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1989

Prevention of tourniquet pain by spinal isobaric bupivacaine with clonidine.

In order to assess the effect of spinal clonidine on tourniquet pain, 30 patients scheduled to undergo orthopaedic surgery under spinal anaesthesia were allocated randomly to two groups. Patients in group I (n = 15) received 0.5% isobaric bupivacaine 15 mg plus isotonic saline 1 ml. Patients in group II (n = 15) received 0.5% bupivacaine 15 mg plus clonidine 1 ml (150 micrograms). Sensory block was evaluated by pinprick and motor block with Bromage's scale. The presence of clonidine significantly prolonged the duration of sensory and motor block. Three patients in group I, but none in group II, experienced tourniquet pain. Hypotension and bradycardia were not worsened by spinal clonidine. The use of clonidine may be a useful technique to augment bupivacaine spinal block.

Adult↗

PubMed1989

Postoperative analgesia with extradural clonidine.

The analgesic effect of extradural clonidine was evaluated in a double-blind study. In the recovery room, following orthopaedic or perineal surgery 20 ASA I and II patients were allocated randomly to two groups. The extradural clonidine (EC) group received clonidine 2 micrograms kg-1 in isotonic saline solution 15 micrograms ml-1. The extradural saline (ES) group received the equivalent volume of plain isotonic saline solution. Pain was evaluated by a visual analogue scale (VAS) at 15-min intervals for the first 2 h and subsequently at 30-min intervals for the following 4 h. Morphine 5 mg was given s.c. when patients complained of pain after extradural saline or clonidine. In the EC group, the mean (SD) maximum pain relief was 68.2 (24.1)% of the initial VAS score, but it was only 14.7 (25.2)% in the ES group. The mean duration of analgesia, before injection of morphine, was significantly longer in the EC group (210 (87) min) compared with the ES group (45 (27) min) (P less than 0.001). Drowsiness and moderate hypotension were observed in the EC group.

Adult↗

PubMed1989

Abnormalities in myocardial segmental wall motion during lumbar epidural anesthesia.

The effect of lumbar epidural anesthesia on myocardial wall motion was compared in two groups of patients using precordial two-dimensional echocardiography (2DE). All patients were scheduled to undergo lower abdominal or peripheral surgery. Group 1 included five healthy ASA PS 1 subjects and group 2 included 10 patients with coronary artery disease (CAD). In all patients 12.5 ml of 2% lidocaine HCl was injected into the lumbar epidural space, and systolic and diastolic blood pressures, and heart rate were continuously monitored. 2DE evaluation was performed before and at 10, 20, 30, and 60 min (T10-T60) after epidural lidocaine injection. The left ventricular wall was divided into 16 segments for parasternal long-axis, short-axis and apical four-chamber views. The wall motion of each segment was graded on a scale from 1 (dyskinesia) to 6 (hyperkinesia), with 5 representing normal motion. A decrease in segmental wall motion greater than or equal to 2 grades was considered indicative of ischemia. Plasma lidocaine and catecholamine levels were measured before and 10, 20, and 60 min after epidural lidocaine injection. Peak plasma lidocaine levels in groups 1 and 2 were 2.79 +/- 1.06 micrograms/ml (mean +/- SD) and 2.58 +/- 1.48 micrograms/ml at 10 min, respectively (NS). Plasma epinephrine and norepinephrine levels were unchanged from baseline. Systolic pressures decreased significantly in group 2 from T10 to T60. Diastolic pressure decreased significantly in the same group from T20 to T60, and in group 1 only at T10. Mean arterial pressure decreased significantly in both groups at T30, without change in heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989