The effect of four different surgical prone positions on cardiovascular parameters in healthy volunteers.

Twenty healthy volunteers were placed in four different surgical prone positions: on pillows, on an evacuatable mattress, on pelvic props and in the knee-chest position. The normal supine position was used as a control for the measurement of cardiovascular parameters. Mean arterial pressure was measured by automated oscillotonometry. Transthoracic electrical bioimpedance was used to measure cardiac output and heart rate. Cardiac index and total vascular resistance index were derived from these data. No significant changes in heart rate or mean arterial pressure occurred when the volunteers were moved from the supine position to any of the four prone positions or when returned to the supine position again. Cardiac index decreased significantly on going from the supine to the knee-chest position (20%) and onto the props (17%) but not onto the evacuatable mattress (11%) or the pillows (3%).

An unusual cause of postoperative brachial plexus palsy.

We describe a case of postoperative brachial plexus neurapraxia after lumbar spinal surgery performed on the prone, seated, knee-chest position. The arms were extended above the patient's head.

Rupture of the symphysis pubis during labor.

Two cases of spontaneous rupture of the symphysis pubis (SP) during delivery are reported. The separations were associated with considerable pain, swelling, and tenderness over the symphysis pubis and were confirmed roentgenographically. Both patients were treated conservatively with bed rest, mostly in the lateral decubitus position, within pelvic binders. Immobilization was discontinued when they were pain free. The SP separations remained in reduced positions. The patients were essentially asymptomatic and walked normally. Conservative treatment followed by early mobilization is adequate treatment for SP separations.

The prone position for the surgical patient: a historical review of the principles and hazards.

Since the 1940s there has been an increase in the number of patients submitted for surgery of the spinal axis necessitating use of the prone position. Specifically designed operating tables were both rare and expensive, and probably only existed in a few highly specialized centres. Apparatus which could be easily made locally and used in conjunction with normal operating tables has been invented and generally used to good effect. The important historical landmarks in these developments are traced and a review of the methods and hazards is presented. Similar methods evolved almost simultaneously in differing centres. It is recommended that the Tarlov "seated prone" position should be widely used, in view of its physiological advantages and lack of adverse reports.

Anaesthesia for the treatment of a giant cerebral aneurysm under hypothermic circulatory arrest.

The anaesthetic management of a patient whose giant cerebral aneurysm was clipped is described. Profound hypothermia and thiopentone were used to provide cerebral protection during circulatory arrest. Atracurium was used to provide muscle relaxation; the level of neuromuscular block and plasma concentrations of atracurium and laudanosine were measured.

A comparative study of methods of detection of esophageal intubation.

The trachea and esophagus of 21 patients were simultaneously intubated to comparatively evaluate methods for detecting esophageal intubation. In succession, the trachea and esophagus were ventilated with the same inspiratory volume of 621 +/- 45 mL (mean +/- SD). Carbon dioxide (CO2) levels, volumes, and temperatures of expired gas were measured from the tracheal and esophageal tubes. End-expired CO2 levels of gases from the trachea and esophagus were 4.9 +/- 0.7% and 0.6 +/- 0.6%, respectively, with CO2 waveforms observed in 7 (33%) patients with esophageal intubations. Volumes expired from the tracheal tube averaged 615 +/- 64 mL and from the esophageal tube 35 +/- 16 mL (P less than 0.001). Peak temperatures of expired gas recorded from the tracheal tube (32.0 +/- 0.73 degrees C) were higher than those from the esophageal tube (27.3 +/- 1.2 degrees C) (P less than 0.001). The shape of temperature waveforms with a correctly placed tracheal tube remained constant with each ventilation, contrary to that obtained from an esophageal tube. Although the occasional detected of CO2 waveforms from an esophageal tube might lead to an incorrect assessment of tube placement, this limitation of CO2 analyzer can be offset by measurement of volume and temperature of expired gas in identifying placement of an endotracheal tube.

Phenytoin infusion in severe pre-eclampsia.

Intravenous phenytoin sodium was given as a high-dose infusion (10 X 8-18 mg/kg) for anticonvulsive prophylaxis to 2 eclamptic patients and to 24 patients with moderate to severe pre-eclampsia. There were no major maternal or neonatal side-effects. Plasma phenytoin levels were within the therapeutic range (7-20 mg/l) at 30 min and 6 h after the infusion in all patients, and remained at a therapeutic level in 21 patients after 12 h. After a second dose of phenytoin in 19 patients, drug levels were within the therapeutic range at 24 h.

Bacteriological swabs in hip surgery.

A prospective trial was carried out in 70 patients undergoing elective total hip replacement, in order to correlate bacterial contaminants in the wound at operation with the subsequent clinical results. A new method of collecting bacteria via a swab left in the wound for the duration of the operation proved to be as effective as the conventional swabbing technique in patients with known previous hip sepsis who, following revision surgery, showed evidence of further infection.

Absence of the pituitary gland in a case of congenital sacral agenesis.

We report for the first time the combination of congenital sacral agenesis and congenital absence of the pituitary gland. This rare association is described in a baby born to a diabetic mother. The baby died at the age of 11 weeks after a cardiorespiratory collapse. The findings at necropsy, which included unusual neurological and visceral anomalies, are reported. We draw attention to the increasing evidence that maternal diabetes is a factor in producing foetal malformations.

Orthopaedic problems in adult hypophosphatasia: a report of two cases.

Hypophosphatasia in adults is rare. Two elderly sisters presenting with pathological fractures of the femur are reported to illustrate the difficulties in orthopaedic management of this disease. All patients with a history of repeated fractures, especially from minor trauma and with generalised radiological bony abnormality, should be screened for this rare disease. A consistently low level of serum alkaline phosphatase with the presence of phosphoethanolamine in the urine is diagnostic.

Radioisotope dilution technique for measurement of blood loss associated with lower segment caesarean section.

Using a 51Cr-labelled red cell dilution technique, the blood loss associated with elective lower segment Caesarean section was measured in 30 patients, half of whom had a previous history of Caesarean section. The blood loss (mean +/- SD) was 1290 +/- 240 ml for first Caesarean sections and 1012 +/- 380 ml for repeat operations.

Topical cocaine and general anaesthesia: an investigation of the efficacy and side effects of cocaine on the nasal mucosae.

A double-blind investigation has been carried out using three different doses (20, 35 and 50 mg) of cocaine which were sprayed onto the nasal mucous membranes of forty-five patients for nasal surgery. The cocaine was administered after induction of general anaesthesia in all cases. The 20 mg dose of cocaine dissolved in 2 ml of saline without adrenaline was found to be safe and produced adequate nasal decongestion in the absence of other predominant factors. The efficacy of cocaine and its safety with regard to systemic absorption are assessed.