Biomedical subjects

A A Van Zundert

Publications and source records attributed to A A Van Zundert.

12 recordsLinked to original sources

PubMed2003

Influence of maternal position during epidural labor analgesia.

The influence of maternal position on the spread of local anesthetics in low concentration has not been well examined during epidural analgesia for labor. This study was designed to investigate the differences in sensory block, pain relief and incidence of supine hypotensive syndrome between parturients in the left lateral position and in a modified supine position. Sixty-seven parturients were randomly assigned to lie either in the left lateral position (n = 34) or in a modified supine position (n = 33), and received 0.125% bupivacaine 10 mL with epinephrine 1:800000 and sufentanil 7.5 microg. At 20 min parturients in the modified supine position turned to the left lateral position and a second investigator, unaware of the initial position, measured the extent of the sensory block at 20 and 30 min and just before a second epidural injection was requested. More dermatomes were blocked on the dependent side when the dose was injected in the left lateral position (at 20 and 30 min: P < 0.05; before the second epidural injection: P < 0.0005). In the modified supine position the incidence of bilaterally blocked dermatomes T10-L1 was greater at 20 and 30 min (P < 0.05) and the pain on a visual analogue scale was better at 30 min (P < 0.05). Three parturients in the modified supine position had signs and symptoms of supine hypotensive syndrome. We conclude that injecting in the modified supine position results in a more equal spread of local anesthetic and better pain relief.

Clinical Trial↗

PubMed1998

Sevoflurane pharmacokinetics: effect of cardiac output.

Sevoflurane uptake (Vsevo) can be predicted by the square root of time model or the four-compartment model. However, Vsevo and the effect of cardiac output on anaesthetic uptake have not been quantified clinically. After obtaining IRB approval and informed consent, 34 adult patients received closed-circuit anaesthesia with sevoflurane for 1 h. The end-expired sevoflurane concentration was maintained at 2.6% by infusion of liquid sevoflurane into the breathing system. In a subgroup of 12 patients, cardiac output was measured every 5 min by thermodilution (CO group). The effect of patient characteristics (age, height, weight, body surface area) and cardiac output on Vsevo were determined, and Vsevo was compared with the theoretical models. In the CO group, measured cardiac output was used in the formulae of these models. A two-exponential curve described average Vsevo well: Vsevo (ml liquid) = 0 + 1.62 x (1 - e(-2.3)xt) + 18.1 x (1 - e(-0.0089xt), r2 > 0.999. There was no correlation between Vsevo and patient characteristics, except that Vsevo was greater in patients with a greater cardiac output (r2 = 0.36) and cardiac index (r2 = 0.35). The rate of sevoflurane uptake decreased less than predicted by the square root of time and four-compartment models, even when measured cardiac output was used in the formulae. These findings confirm that the square root of time and four-compartment models do not accurately predict anaesthetic uptake. In addition, uptake of sevoflurane cannot be predicted by patient characteristics but was higher in patients with a higher cardiac output.

Adolescent↗

PubMed1998

Coronary artery spasm during anesthesia for liver resection.

Intraoperative coronary artery spasm (CAS) is rare, and most cases have been reported during cardiac surgery (4, 7, 12). The following is a case report of a patient undergoing liver resection developing CAS, resulting in well-documented ST-segment elevation in lead II and V5 of the electrocardiogram (ECG) and severe hemodynamic instability. The coronary spasm was successfully treated with intravenous nitroglycerin. Postoperatively, a coronary angiogram documented CAS in the absence of significant coronary artery disease, confirming the clinical diagnosis of CAS.

Anesthesia, Intravenous↗

PubMed1989

A fatal accident after epidural anesthesia for cesarean section.

It is a sobering fact that mishaps during the administration of anesthesia sometimes have a way of initiating problems which escalate step by step to a situation of total disaster for the patient. Inexperience and poor judgment often lie behind such tragedies and the following case report is presented not only as an illustration of this, but also as a useful lesson. The authors only became involved in this case after the anesthesiologist concerned made available his account of the clinical events together with the hospital records. For obvious reasons the anesthesiologist's name has not been given, but he has given his full permission to publish this case. A case report is presented in which a healthy 31-year-old a term para II, requested epidural anesthesia for an elective Cesarean section for pelvic disproportion. Repeated attempts to perform epidural anesthesia were necessary. Eventually she developed acute pulmonary edema and resuscitation was not successful. Both mother and fetus died.

Acute Disease↗

PubMed1989

Emergency aortic valve replacement in the 24th-week of pregnancy.

The incidence of heart disease during pregnancy has declined from 3.6% to approximately 1.5% over the last 25 years as a result of better medical and surgical care. Rheumatic heart disease still accounts for 75% of cases and the incidence of bacterial endocarditis during pregnancy is about 1 in 8000. Seaworth and Durack reviewed 124 cases found in the literature of a 40 year period. The experience of any anesthetist with such cases will thus be limited. In this case report a patient is described who required emergency aortic valve replacement in the 24th week of pregnancy. The effect of the non-pulsatile flow during the extracorporeal circulation on the foetal unit will be discussed. Recommendations for the perioperative management include a normothermic high flow, high pressure perfusion technique, monitoring of foetal heart rate and uterine activity and vigorous tocolysis using beta sympathomimetics and progesterone.

Acute Disease↗

PubMed1988