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Biomedical subjects

J Norman

Publications and source records attributed to J Norman.

16 recordsLinked to original sources

Postoperative analgesia: a comparison of intravenous on-demand fentanyl with epidural bupivacaine.

In a randomised trial postoperative pain relief was provided by either epidural injections of bupivacaine or an infusion of fentanyl adjusted by the patient to achieve adequate pain relief. Both techniques produced satisfactory analgesia without respiratory depression after peripheral arterial surgery. The technique of infusing intravenously a potent analgesic in a dose adjusted by the patient appears to offer several advantages in postoperative care.

Blood Gas Analysis

Resistance of Heidbrink-type expiratory valves.

The minimum resistance of expiratory Heidbrink-type value has been assessed by determining the pressure decrease across the values at a flow rate of 30 litre min--1. The average resistance of 70 valves currently in clinical use was 318 Pa at that flow rate and about 44% had resistances greater than the limit of 294 Pa previously suggested. The resistances obtained in new valves were either similar or fractionally greater. Valves being introduced as parts of scavenging systems appeared, on the whole, to have lower resistances.

Anesthesia, Inhalation

Myocardial and plasma levels of adenosine 3':5'-cyclic phosphate. Studies in experimental myocardial ischemia.

Alterations in myocardial and plasma levels of adenosine 3':5'-cyclic phosphate (cyclic AMP) were studied following clamping of the aorta or coronary artery occlusion in 30 dogs. Plasma cyclic APM levels increased markedly after thoracotomy but returned to control levels two hours later. Complete arrest of aortic flow (clamping) induced a significant early increase in the myocardial cyclic AMP levels of all animals studied. No increase was noted following pretreatment with propranolol or sham-occlusion. After localized coronary occlusion, only modest and insignificant changes occurred in plasma cyclic AMP levels in anesthetized animals and also in conscious dogs. The present study suggests that adrenergically mediated changes in tissue cyclic AMP content are an early manifestation of both generalized and local myocardial ischemia, while the plasma cyclic AMP level is a relatively insensitive indicator of small coronary occlusions.

Animals