EFFECT OF AN ACUTE INCREASE IN CEREBROSPINAL FLUID PRESSURE ON LUNG COMPLIANCE IN THE RABBIT

Cerebrospinal fluid pressure (P_csf) was increased acutely bythe injection of normal saline into the cisterna magna of anaesthetizedrabbits to values which interrupted cerebral blood flow. Whenincreased P_csf was maintained for a minimum of 3 min, staticlung compliance decreased and lung weight (after sacrifice)increased without marked change in arterial blood-gas tensions.The magnitude of the increase in P_csf did not affect the changein compliance and weight. There was marked unexplained metabolicacidosis. The pulmonary findings may result from a massive shiftof blood from the systemic to the pulmonary circulation leadingto increased permeability of the inter-endothelial junctionsof the pulmonary capillaries.     

EXPERIMENTAL STUDIES ON INTRAVENOUS REGIONAL ANAESTHESIA USING RADIOACTIVE LIGNOCAINE

Experiments using ¹⁴C-labelled lignocaine administered by theintravenous regional anaesthetic technique were carried outin dogs in order to determine the site and mode of action oflignocaine used in this way. Preliminary results have showna statistically significant selective pick-up by nerve tissuealthough the actual site of action has not yet been determined.Blood lignocaine levels in the venous outflow of the limb afterremoval of the tourniquet were also determined. The peak levelsrecorded were beneath the concentrations considered to be dangerousin clinical practice.     

TRACHEOSTOMY COMPLICATIONS IN AN INFANT: A Case Report

A case of upper respiratory tract obstruction in a 5-month-oldinfant is described. Difficulties in establishing a tracheostomywere encountered and orotracheal intubation was used to providea clear airway. The patient died suddenly 15 hours later. Possiblemechanisms accounting for the failure of resuscitation are discussed.The merit of prolonged endotracheal intubation and tracheostomyin the infant are compared.     

INTERMITTENT MANDATORY VENTILATION DURING ANAESTHESIA USING THE MANLEY SERVOVENT VENTILATOR

The lungs of 25 patients were ventilared with intermittent mandatoryventilation (IMV) during anaesthesia using the Manley ServoventModel MS. This ventilatory mode is especially suitable for prolongedoperations in which there is no need for muscle relaxation.While incorporating the advantages of spontaneous and mechanicalventilation, it is superior to both in selected cases. The ManleyServovent Model MS ventilator is capable of delivering IMV withoutmodification, using a single source of gas.     

OBSERVATIONS ON EXTRADURAL MORPHINE ANALGESIA IN VARIOUS PAIN CONDITIONS

We report the extradural administration of low-dose morphinein 10 ml of % dextrose (2–3 mg) to 98 adult patients withvarious types of acute and chronic pain. Extradural morphineinjections were given either via a Tuohy needle (single or repeatinjection) or via an extradural catheter. Pain relief was evaluatedby subjective scoring and by the subsequent need for systemicanalgesics. In 56% of patients, pain relief was considered goodor excellent, in 24% it was fair, and in 20%, poor. The bestresults were after surgery and trauma and in patients with advancedperipheral vascular disease. The analgesia of each dose of extraduralmorphine lasted for 8 h (mean range 4–36 h). There wasno motor, sensory or sympathetic blockade and no respiratoryor haemodynamic complications. Dizziness and vomiting occurredin two patients, and urinary retention for about 12 h in three.