bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypoxaemia during Postoperative Recovery using Continuous Pulse Oximetry
Authors: Brown L. T. , Purcell G. J. , Traugott F. M.
Published: January 2019

Continuous pulse oximetry monitoring was used to determine the incidence of hypoxaemia (arterial oxygen saturation ≤ 90%) occurring in the first hour of postoperative recovery. Of 107 patients studied, hypoxaemia was recorded in 80%. Twenty-eight (26%) of these patients had saturations below 80%. The average frequency (i.e., the number of desaturations per patient) and the total duration of these desaturations was 7.7 desaturations and 182 seconds respectively. Intermittent measurements taken preoperatively and at 5 and 30 minutes postoperatively revealed hypoxaemia in 2%, 4% and 6% of patients respectively. In 39 patients who received oxygen therapy throughout the monitoring period, 64% experienced hypoxaemia within the first 15 minutes of recovery as opposed to only 18% in the final 15 minutes monitoring period. Of the factors assessed, only patients with a body mass index > 25 had an increased risk of hypoxaemia (P < 0.01). Four patients required active intervention and ventilatory assistance. We conclude that postoperative hypoxaemia is a particularly common occurrence even in patients otherwise considered healthy. Hence, pulse oximetry should be employed routinely during recovery. Where possible, monitoring should be performed continuously for at least 45 minutes.
Unlimited Clear Fluid Ingestion Two Hours before Surgery in Children does not Affect Volume or pH of Stomach Contents
Authors: Splinter W. M. , Schaefer J. D.
Published: January 2019

To determine the effect on gastric contents of unlimited clear fluid ingestion by children up to two and a half hours and then up to two hours before elective surgery, 228 healthy children (ages two to twelve years) were prospectively studied. During Phase I of this study subjects ingested unrestricted volumes and types of clear fluids up to three hours (control group) or two and a half hours before surgery. After establishment of adequate anaesthesia, gastric fluids were aspirated via an orogastric tube. Gastric volume was measured with a syringe and gastric pH was determined. After determining that there was no adverse effect associated with reducing a clear fluid fast to two and a half hours, Phase II of the study was begun. The methods for Phase II were unchanged except that unlimited clear fluids were permitted up to three hours (control group) or two hours preoperatively. In both Phase I and II, gastric volume and gastric pH were unaffected by reducing the fast to less than three hours. It is concluded that ingestion of unlimited clear fluids up to two hours before elective surgery does not affect gastric contents of healthy children.
A Study of Preoperative Fasting in Infants Aged Less than Three Months
Authors: van der Walt J. H. , Foate J. A. , Murrell D. , Jacob R. , Bentley M.
Published: January 2019

The effects of preoperative fasting on plasma glucose and gastric emptying was studied in 62 infants aged less than three months after a feed of either breast milk or an infant milk formula. Prior to induction of anaesthesia no infant was hypoglycaemic, defined as plasma glucose <2.2 mmol/l. Five per cent of infants had a significant volume of residual gastric contents. The mean intraoperative plasma glucose levels rose significantly and this was not influenced by the use of intravenous Hartmann ‘s solution or low dose opioids. Infants in this age group tolerate three- to four-hour preoperative fasts well as no infant became hypoglycaemic intraoperatively. They demonstrate a hyperglycaemic response to the stress of anaesthesia and surgery, and may not need routine intraoperative glucose supplements although plasma glucose should still be monitored.
The Stability of Atracurium in Clinical Practice
Authors: Russell W. J. , Meyer-Witting M.
Published: January 2019

Atracurium has an unusual intrinsic Hofmann elimination which is increased by an alkaline environment and increased temperature. Normally the relaxant is stored at pH 3.3 and kept at a temperature of 4°C. However, it is convenient to have a reasonable quantity available within the operating theatre. This study examined the rate of degradation of atracurium in the operating theatre environment of 20°C.

Atracurium within one month of its expiry date was placed in the drawer for anaesthetic drugs in each of three operating theatres. At the end of each month, further drug was added to the stock.

At the end of the study, atracurium which had been stored continuously at 4°C, was at 102.9% of nominal strength, having started with 113.5% at manufacture. Atracurium which had been at room temperature for one, two and three months respectively retained 99%, 95% and 92% strength respectively.

These results show that even three months’ exposure to room temperature does not cause enough deterioration to be clinically significant.
Are Obstetric Spinal Headaches Avoidable?
Authors: Barker P.
Published: January 2019

In a prospective study of one hundred obstetric patients given spinal anaesthesia using either a 25 or 26 gauge spinal needle, a significantly greater incidence of spinal headache and blood patch was found in the 25-gauge group. It is concluded that a 26-gauge needle should be used when performing spinal anaesthetics for obstetric procedures.
C-reactive Protein as a Diagnostic Test of Sepsis in the Critically Ill
Authors: Matson A. , Soni N. , Sheldon J.
Published: January 2019

Changes in the plasma concentration of C-reactive protein were assessed as a diagnostic test for sepsis in critically ill patients. Forty-nine episodes of secondary sepsis were identified in 31 patients. In 43 out of the 49 episodes there was a 25% or greater change in the concentration of C-reactive protein on the day that sepsis was diagnosed but in six episodes of sepsis the change was less than 25%.

A 25% rise in the plasma concentration of C-reactive protein in the absence of other non-infective causes of a raised C-reactive protein, such as inflammation, tissue injury or surgery, is highly suggestive of infection, but failure of the C-reactive protein to rise does not eliminate a diagnosis of sepsis.
Inspiratory Work Imposed by Demand Valve Ventilator Circuits
Authors: Oh T. E. , Lin E. S. , Bhatt S.
Published: January 2019

The inspiratory work (WI) imposed by three commonly used demand valve ventilator circuits was studied using a lung model to simulate spontaneous ventilation. The CPU-1 and Engstrom Erica circuits recorded WI of 379 mJ/l and 190 mJ/l respectively. A negative WI of −32 mJ/l was recorded for the Servo 900C, denoting that the circuit performed work on the lung. The demand valves recorded a time delay between inspiratory effort and onset of gas flow, of 300 ms (CPU-1), 190 ms (Servo 900c) and 160 ms (Engstrom Erica). Both the Servo 900C and Engstrom Erica demand valves were able to generate a high inspiratory gas flow response, but the CPU-1 lacked such a flow compensation. Expiratory work was also greatest with the CPU-1 (156 mJ/l) with 141 mJ/l and 90 mJ/l recorded for the Servo 900C and Engstrom Erica. Of the three ventilators studied, the Servo 900C appears to be the ventilator circuit of choice for spontaneous ventilation.
Arterial Desaturation during Induction in Healthy Adults: Should Preoxygenation be a Routine?
Authors: Kung M. C. , Hung C. T. , Ng K. P. , Au T. K. , Lo R. , Lam A.
Published: January 2019

We studied the haemoglobin saturation of one hundred healthy patients equally divided into two groups. Group 1 patients received three minutes of preoxygenation prior to thiopentone induction followed by inhalational anaesthetics. Group 2 patients breathed room air prior to induction. None of the patients in Group 1 showed any arterial oxygen desaturation during the five minutes of the induction period, whereas 21 patients in Group 2 showed definite desaturation (P < 0.005), of which fifteen patients had a saturation of 90% or less (P < 0.005) and six had a saturation of 85% or less. Since those were healthy patients and the anaesthetics were given by experienced anaesthetists, we concluded that some form of preoxygenation should be used in all patients receiving general anaesthesia.
A Comparison of Two-Lung High Frequency Positive Pressure Ventilation and One-Lung Ventilation plus 5 cm H2O Non-Ventilated Lung CPAP, in Patients Undergoing Anaesthesia for Oesophagectomy
Authors: Tsui S. L. , Chan C. S. , Chan A. S. H. , Wong S. J. , Lam C. S. , Jones R. D. M.
Published: January 2019

A randomised prospective controlled study was conducted during a one-year period on patients scheduled/or oesophagectomy via a right thoractomy approach. Twenty-two patients received one-lung ventilation (OLV group) and twenty patients received high frequency positive pressure ventilation (HFPPV group). Episodic hypoxaemia (SaO2 < 90% for > 30 seconds, FiO2 1.0) occurred in eleven patients in the OLV group and six patients in the HFPPV group. No patient in the HFPPV group had a severe desaturation episode (SaO2 < 80%, FiO2 1.0) compared with nine patients in the OLV group (P < 0.05). The mean peak inspiratory pressure and average mean airway pressure were significantly lower in the HFPPV group 28.8 (SD 7.7) and 7.2 (SD 2.4) cm H2O respectively, compared with the OLV group, 40.0 (SD 9.9) and 11.9 (SD 4.9) cm H2O (P < 0.05).

Two-lung high frequency positive pressure ventilation has some advantages over one-lung ventilation during the thoracotomy phase of oesophagectomy because it is easy to administer, does not significantly compromise the surgical exposure and is associated with fewer severe undesirable physiological disturbances.
Biliary Excretion of the Halothane Metabolite Trifluoroacetic Acid in Infants
Authors: Wark H. , Earl J. , Chau D. , Overton J.
Published: January 2019

In humans the biliary excretion of trifluoroacetic acid, the major halothane metabolite, has not been studied. We investigated the biliary excretion of trifluoroacetic acid in two infants aged five months and two months following halothane anaesthesia for the operation of choledocholithotomy. Bile, urine and faeces were collected continuously for five days after operation and trifluoroacetic acid excretion measured. Estimates of halothane uptake, daily bile flow and the proportion of daily bile flow collected via the T-tube drainage catheter were subject to percentage errors possibly as large as 50%. Of the total trifluoroacetic acid produced from halothane metabolism, it was estimated that 17% in the five-month-old infant and 20% in the two-month infant was excreted in bile. In the five-month-old infant where approximately 80% of the bile produced entered the duodenum in the normal way, no faecal trifluoroacetic acid was detected suggesting an enterohepatic circulation for this metabolite.
An Evaluation of One Method of Ventilation for Laser Therapy to the Tracheobronchial Tree
Authors: Smith P. G. , Murphy D. F.
Published: January 2019

Laser therapy has been used extensively for surgery to the respiratory tract since its first application in 1971. At this hospital, the surgeon's preferred technique for laser surgery to the tracheobronchial tree is to use the Nd-YAG laser through a fibreoptic bronchoscope passed through a rigid bronchoscope. General anaesthesia is employed and ventilation is controlled using jet-ventilation by the Sanders technique. Review of the literature failed to locate adequate information on the effect of manoeuvres such as insertion of instruments and the presence of a tracheal obstruction distal to the bronchoscope on the quality of ventilation using this technique. A bench study was undertaken, therefore, in an attempt to mimic such clinical situations and to assess the effect of such manoeuvres on the adequacy and pattern of ventilation. Under all conditions tested ‘end-tidal’ CO2 concentrations accurately reflected distal ‘tracheal’ concentrations. The lowest inspired O2 concentration was 50% while entraining air through the bronchoscope. The highest was 86% while entraining oxygen.
The Influence of Epidural Pethidine on Shivering during Lower Segment Caesarean Section under Epidural Anaesthesia
Authors: Sutherland J. , Seaton H. , Lowry C.
Published: January 2019

A prospective study of 94 patients undergoing elective lower segment caesarean section under epidural anaesthesia was performed in order to determine the incidence of shivering and the influence of epidural pethidine.

Epidural anaesthesia was established with bupivacaine 0.5% with adrenaline, with or without additional lignocaine 2% with adrenaline, to total 20–25 ml. With the injection of epidural local anaesthesia an extra 5 ml of solution was administered into the epidural space – pethidine 25 mg preservative-free, in normal saline, or normal saline alone. Patient, administering anaesthetist and observer were blinded to the nature of the test substance. Shivering was assessed by an independent observer and subsequently rated by the patient. Other side-effects also recorded were nausea, vomiting, pruritis and drowsiness.

The incidence of shivering was 36% in the control (saline) group and 11% in the pethidine group. The difference was highly significant (P < 0.01). There was no significant difference in the incidence of maternal nausea, vomiting, drowsiness or pruritis, or neonatal Apgar scores. Cord blood samples were assayed for pethidine, revealing low or absent pethidine concentrations.
Tests of Six Continuous Flow CPAP Devices
Authors: Shehabi Y. , Hillman K. M. , Nairn M. , Balnave P. , Torda T. A.
Published: January 2019

Six continuous flow CPAP devices were tested for pressure fluctuation and stability of inhaled oxygen concentration under conditions of simulated respiration. Four of the systems, the Ambu, Auspap, Downs'-Vital Signs and the Dräger are commercially available and two, the Prince Henry (PHH) and the Prince of Wales (POW) systems were assembled from Bird respirator parts, which were available in the respective Intensive Care Units. All appeared to be clinically effective. The Ambu offers convenience and economy of gases, the Dräger showed the least pressure fluctuations. Three of the four commercial systems lacked certain safety features which could more easily be added to the two non-commercial devices.
Experience with the Laryngeal Mask Airway in Two Hundred Patients
Authors: McCrirrick A. , Ramage D. T. O. , Pracilio J. A. , Hickman J. A.
Published: January 2019

Observations were recorded from two hundred consecutive insertions of the laryngeal mask airway (LMA). They were undertaken by 27 anaesthetists most of whom had no previous experience of its use. A clinically patent airway was obtained in 94% of patients and in the majority of these (76%) the LMA was positioned correctly at the first attempt. There were twelve cases of failed insertion. Nine of these were as a result of an inability to pass the LMA correctly into the hypopharynx while in the remaining three cases complete airway obstruction was reported. The insertion technique was easily acquired and trainee anaesthetists achieved a success rate of 84% for their first five attempts. Success with the LMA was related to experience: anaesthetists who had used the LMA over 15 times had no failures in 67 insertions. Twenty-two patients coughed and six developed mild laryngospasm at insertion. The incidence of postoperative sore throat was 8%.
Postoperative Hospital Admission from a Day Surgery Unit: A Seven-Year Retrospective Survey
Authors: Biswas T. K. , Leary C.
Published: January 2019

Postoperative hospital admissions from a hospital-based Day Surgery Unit were reviewed during the period 1984 to 1990. There were 18,321 procedures performed in different specialties. Of these, 225 patients required hospital admissions — a rate of 1.2%. Highest admission rate was found in gynaecological surgery (100 out of 225).

Laparoscopic procedures accounted for 64 admissions, of which 13 were due to visceral perforations Urological surgery resulted in 35 admissions (4.5% of the urological caseload). Perhaps this reflects the patient age group and preexisting medical conditions. Interestingly, there were 13 admissions for social reasons.

Many of these admissions were due to either multiple procedures or surgery more extensive than planned.

Even with the higher rate of admissions, hospital-based centres probably provide a better quality care for those who require major surgery or develop some complications in the perioperative period.
Propofol is a ‘Safe’ Anaesthetic Agent in Malignant Hyperthermia Susceptible Patients
Authors: McKenzie A. J. , Couchman K. G. , Pollock N.
Published: January 2019

In this study we investigated in vitro and in vivo effects of propofol in malignant hyperthermia susceptible (MHS) patients in order to assess the safety of propofol infusion as a non-triggering anaesthetic technique for diagnostic and therapeutic procedures.

In vitro, human MHS muscle samples were exposed to propofol and changes in (a) baseline tension and (b) contracture tension on exposure to halothane and caffeine were measured.

In vivo, (a) anaesthesia was induced in ten muscle biopsy positive MHS patients with propofol 2.5 mg/kg and (b) anaesthesia was produced in five muscle biopsy positive MHS patients with infusions of propofol up to 10 mg/kg/hr.

In vitro, human MHS muscle did not develop contractures with propofol alone. Propofol had no significant effect on contracture development in response to halothane and caffeine. In vivo, no evidence of an MH response was detected following induction or maintenance of anaesthesia with propofol.

Our results and literature review are in agreement that propofol is a ‘safe’ induction and maintenance agent in MHS patients. Propofol can be used for muscle biopsy anaesthesia because it does not alter the sensitivity of diagnostic muscle biopsy testing.
Double-blind Comparison of Patient Recovery after Induction with Propofol or Thiopentone for Day-case Relaxant General Anaesthesia
Authors: Chittleborough M. C. , Osborne G. A. , Rudkin G. E. , Vickers D. , Leppard P. I. , Barlow J.
Published: January 2019

Postoperative recovery after induction with either propofol or thiopentone has been compared in forty ASA I unpremedicated day surgery patients undergoing surgical extraction of third molar teeth under relaxant general anaesthesia. Mean recovery times in the propofol group, required for patients to sit out of bed (44.8 minutes; SD 18.6) and meet discharge criteria (113.1 minutes; SD 34.5) were significantly (P < 0.05) shorter than those in the thiopentone group (59.7 minutes; SD 21.4 and 133.5 minutes; SD 34.5). Fewer patients in the propofol group were treated in the recovery room for nausea and vomiting and the incidence of mild nausea not requiring treatment was less in the propofol group, but these differences were not statistically significant. Postoperative mental performance, measured by the FAST index, a new test of mental speed, was reduced on average by 1.7% of preoperative levels, during the recovery period tested, with no significant difference between the groups.
Uptake of Enflurane and Isoflurane during Spontaneous and Controlled Ventilation
Authors: Bengtson J. P. , Bengtsson A. , Stengvist O.
Published: January 2019

The uptake of enflurane and of isoflurane were studied in forty patients during anaesthesia with nitrous oxide using either spontaneous or controlled ventilation. A Douglas bag method was used in combination with low fresh gas flows to a circle system and constant end-tidal anaesthetic concentration. The mean enflurane uptake rates were between 24 and 14 ml. 70 kg−1.min−1 between 10 and 60 minutes. Corresponding isoflurane uptake rates were between 15 and 8 ml. 70 kg−1.min−1. The initial uptake rates were lower than expected from “the square root of time concept”. During spontaneous ventilation, the anaesthetic uptake rates were similar or even higher than corresponding rates during controlled ventilation in spite of lower minute ventilation volumes.
The Effects of Oxytocin on the Pulmonary and Systemic Circulation in Pregnant Ewes
Authors: Roberts N. V. , Keast P. J. , Brodeky V. , Oates A. , Ritchie B. C.
Published: January 2019

The haemodynamic effects of oxytocin on the pulmonary and systemic circulation were studied in six awake, pregnant (> 140 days gestation) ewes. Bolus doses of oxytocin 0.2 units/kg and then 0.8 units/kg were administered. A dose of 0.2 units/kg resulted in small but significant increases in mean pulmonary artery pressure (14%, P < 0.05) and pulmonary vascular resistance (24%, P < 0.05. A bolus of 0.8 units/kg resulted in a significant increase in mean arterial pressure (20%, P < 0.05) and systemic vascular resistance (33%, P < 0.05).

Acute pulmonary hypertension was then induced with glass bead microemboli (150–200 μm), with an increase in pulmonary artery pressure of 26 mmHg and pulmonary vascular resistance of 448 dyn. s. cm−5. Boluses of oxytocin 0.2 and 0.8 units/kg were then administered. There were no significant changes, except for a 30% increase in systemic vascular resistance at one minute after oxytocin, 0.8 units/kg (P < 0.05).
Aminoglycoside Volume of Distribution and Illness Severity in Critically Ill Septic Patients
Authors: Marik P. E.
Published: January 2019

The volume of distribution of amikacin and the APACHE II score were determined in 42 critically ill patients being treated for a gram-negative infection. The mean volume of distribution (Vdt) was 0.41±0.12 l/kg with a wide range (normal of 0.25 l/kg). There was a good relationship between the Vdt and illness severity as measured by the APACHE II score (r=0.70; P<0.001). Critically ill patients should receive larger loading doses of aminoglycosides in order to achieve therapeutic blood levels. The aminoglycoside Vdt may be useful in determining the degree of capillary leak and tissue oedema that accompanies sepsis.
Background Infusion with Patient-Controlled Analgesia: Effect on Postoperative Oxyhaemoglobin Saturation and Pain Control
Authors: Russell A. W. , Owen H. , Ilsley A. H. , Kluger M. T. , Plummer J. L.
Published: January 2019

The aim of this study was to determine whether the addition of a background infusion (BI) to patient-controlled analgesia (PCA) would lead to significantly improved pain control or poorer oxyhaemoglobin saturation (SpO2) after gynaecological surgery. Sixty-two patients were studied for 24 hours postoperatively; pain scores and morphine dose were recorded hourly, SpO2 was recorded every 10 seconds. Administration of the BI resulted in a significant increase in total morphine dose received although there was no difference in the severity of postoperative desaturation between the therapies. Despite the increased morphine dose pain scores also were similar in the two groups. Addition of a BI at 1 mg/hr did not confer any advantage over PCA alone and is not recommended when PCA is used in this patient group.
Ondansetron 4 mg for the Prevention of Nausea and Vomiting after Minor Laparoscopic Gynaecological Surgery
Authors: Suen T. K. L. , Gin T. A. , Chen P. P. , Rowbottom Y. M. , Critchley L. A. H. , Ray A. K.
Published: January 2019

We studied the efficacy and safety of intravenous ondansetron 4 mg for the prevention of postoperative nausea and vomiting after minor gynaecological laparoscopic surgery in Oriental women. This double-blind randomised study compared ondansetron with placebo, given before the induction of anaesthesia. The anaesthetic technique used thiopentone, fentanyl, atracurium, nitrous oxide and isoflurane. Patients were studied for 24 h with nausea assessed using a verbal numeric scale from 0-10 and emetic episodes recorded as they occurred.

Results were available for 102 patients in each group. In the first postoperative hour, fewer patients in the ondansetron Group (12%) had emetic episodes compared with the placebo group (33%, P <0.01). Nausea score over the first hour (sum of three readings at 0, 30 and 60 min) was lower in the ondansetron group (median 1.6) compared with the placebo group (3.1, P <0.05). Over the 24 h period, fewer patients in the ondansetron group had emetic episodes (25%) or nausea (43%) compared with patients in the placebo group (56%, P <0.01) and (58%, P <0.05) respectively. No adverse events were seen.

Ondansetron 4 mg was more effective than placebo in preventing postoperative nausea and vomiting throughout the 24 h after minor laparoscopic surgery.
Efficacy of Low-Dose Epidural Anaesthesia in Surgery of the Anal Canal—A Randomised Controlled Trial
Authors: Kausalya R. , Jacob R.
Published: January 2019

The aim of the study was to compare in terms of patient comfort, surgical requirements and anaesthetic safety, the difference between epidural and general anaesthesia in patients undergoing surgery of the anal canal. The study was undertaken on 50 adult patients undergoing anal surgery. By random allocation 25 were given a general anaesthetic while 25 were given a low-dose epidural using 0.375% bupivacaine. Advantages and disadvantages of both methods were noted in the study. It was concluded that low-dose epidural is a more effective means of providing analgesia, while maintaining adequate sphincter tone for surgery on the anal canal, than general anaesthesia.
Intensive Care Costing Methodology: Cost Benefit Analysis of Mask Continuous Positive Airway Pressure for Severe Cardiogenic Pulmonary Oedema
Authors: Holt A. W. , Bersten A. D. , Fuller S. , Piper R. K. , Worthley L. I. G. , Vedig A. E.
Published: January 2019

Costing data for intensive care admissions is important, not only for unit funding, but also for cost outcome analysis of new therapies. This paper presents an intensive care episode costing methodology using the example of a cost-benefit analysis of mask CPAP for severe cardiogenic pulmonary oedema (CPO). This analysis examines the intervention of admitting all patients with severe CPO to the intensive care unit for mask CPAP, compared with the previous practice of admitting only patients failing conventional non-CPAP treatment and requiring mechanical ventilation.

The episode costs were determined from a prospective study which showed mask CPAP reduced the need for mechanical ventilation from 35% to 0%. The mean cost of a mask CPAP episode was $1,156, with a mean stay of 1.2 days, compared with ventilated patients, $5,055 and 4.2 days. The major contributors to cost in both groups were nursing and medical salaries, and hospital overheads.

The cost of previous estimated yearly caseload of 35 ventilated patients ($176,925) was greater than the cost associated with an increased caseload of 100 mask CPAP patients ($115,600).

We conclude that, despite an increase in admissions, mask CPAP for severe CPO is cost-effective.
The Use of Steroids and Nebulised Adrenaline in the Treatment of Viral Croup over a Seven Year Period at a District Hospital
Authors: Mcdonogh A. J.
Published: January 2019

The medical records of 787 patients admitted with a diagnosis of viral croup between January 1986 and December 1992 were examined. The study was prompted by an observed change in the pattern of admissions to the intensive care unit at a large district hospital during the late 1980s. Changes in the pattern of use of adrenaline and steroids were noted.

An increase in the dose and frequency of administration of steroids and nebulised adrenaline occurred during the years of the study. In 1992 one-third of patients were given nebulised adrenaline on admission. In the same year 87% of patients were given a dose of steroid. Despite an increase in the number of patients admitted with viral croup, there was a marked reduction in the number of patients requiring admission to intensive care or intubation during the years of the study.

This information supports the early aggressive use of steroids and nebulised adrenaline in the management of moderate to severe viral croup.
Pharmacokinetics of Bupivacaine Enantiomers during Interpleural Infusion
Authors: Blake D. W. , Bjorksten A. , Dawson P. , Hiscock R.
Published: January 2019

Interpleural infusions (24 hr) were given to 14 adults (29-81 yr) having surgery via right subcostal incisions. Patient-controlled analgesia with morphine was also available for 72 hours following surgery. An infusion of 0.25% bupivacaine with adrenaline 1/400,000 was commenced at 0.1 ml/kg/hr at the conclusion of surgery after an initial 20 ml bolus. The 24 hr cumulative morphine dose increased by 62% (P < 0.01) on the second postoperative day after the bupivacaine infusion was ceased, but the pain score did not change. There was no clinical evidence of bupivacaine toxicity although the maximum bupivacaine concentration ranged from 0.74-6.52 mg/l, mean 2.90 (SEM 0.44) mg/l and vascular uptake was rapid in two patients. The concentration of S-bupivacaine was consistently greater than R-bupivacaine (P < 0.05) and total body clearance was less. The unbound bupivacaine fraction also changed from 3.6% (SEM 0.6) at the start of the infusion to 2.0% (SEM 0.3) at 24 hr (P < 0.005). The total body clearance of each enantiomer was reduced during the 24 hours (P < 0.001). No relationship between pharmacokinetic parameters and weight, age or sex was found (P>0.25 for each). Variation between patients was reduced when parameters were estimated for the free (unbound) bupivacaine (P < 0.001).
High-dose Aprotinin in Cardiac Surgery—A Prospective, Randomized Study
Authors: Swart M. J. , Gordon P. C. , Hayse-Gregson P. B. , Dyer R. A. , Swanepoel A. L. , Buckels N. J. , Schall R. , Odell J. A.
Published: January 2019

Fifty patients undergoing primary coronary artery bypass surgery and 50 patients undergoing valve surgery received either high-dose aprotinin (2 million units loading dose, 2 million units added to the CPB prime, and 500,000 units/hr maintenance infusion) or placebo. Mean postoperative blood loss in the first six hours was reduced from 321 ml in the placebo group to 172 ml in the aprotinin group (95% confidence interval (CI) for difference = 95 to 189 ml). Seven patients in the placebo group and 16 patients in the aprotinin group did not require transfusion with homologous blood. This study adds to the growing body of evidence that the administration of high-dose aprotinin reduces blood loss and blood transfusion requirements associated with primary cardiac surgery.
A Comparison of Three Induction Agents in Paediatric Anaesthesia—Cardiovascular Effects and Recovery
Authors: Jones R. D. M. , Visram A. R. , Chan M. M. Y. , Bacon-Shone J. , Mya G. H. , Irwin M. G.
Published: January 2019

We studied 30 children undergoing circumcision randomly allocated to receive either thiopentone 4 mg.kg−1, propofol 2.5 mg.kg−1 or midazolam 0.5 mg.kg−1 (n = 10) IV over 30 seconds at induction of anaesthesia. Blood pressure and pulse rate during the first 15 minutes of induction were recorded by a Finapres 2300e and a Cardiocap CM-104, and changes from preinduction baseline compared between the three induction agents and the two recording instruments. Postoperatively, blood levels of the induction agents were measured and recovery from anaesthesia was assessed by clinical criteria, mood and sedation scores and psychomotor performance. The Cardiocap data revealed no statistically significant haemodynamic differences between the three induction agents. Finapres data demonstrated that propofol caused a greater decrease in mean arterial pressure when compared to thiopentone at one minute (P=0.01) and the MAP remained significantly lower than midazolam at five minutes (P=0.02), illustrating an advantage of continuous over intermittent non-invasive blood pressure monitoring. The midazolam group took longer to identify themselves compared to both the propofol (P=0.005) and the thiopentone groups (P=0.02), but there was no difference in the groups in time to eye-opening. Psychomotor performance on awakening was significantly worse in the midazolam group compared to the propofol (P < 0.03) and thiopentone groups (P < 0.02). Most children had recovered to 80% of their best, practised, unmedicated, preoperative performance four hours after awakening, irrespective of the induction agent administered. Drug blood levels correlated weakly with both methods of psychomotor assessment (r ≥ 0.6). Of the three induction agents, thiopentone caused the least haemodynamic perturbation on induction, and anaesthesia induced with midazolam caused the greatest psychomotor impairment on awakening. Within one hour patients in all drug groups were equally awake, co-operative and co-ordinated.
External Abdominal Aortic Compression: A Study of a Resuscitation Manoeuvre for Postpartum Haemorrhage
Authors: Riley D. P. , Burgess R. W.
Published: January 2019

External aortic compression is an emergency manoeuvre proposed to reduce postpartum haemorrhage and permit time for resuscitation and control of bleeding.

To assess this technique, a prospective study was performed on twenty normal non-bleeding parturients. The abdominal aorta was compressed by firm pressure with a closed fist just above the umbilicus. Leg and arm arterial blood pressures were measured and femoral artery pulsation felt before, during and after compression. Leg blood pressure was completely obliterated in 55% and significantly reduced (P < 0.01) in a further 10% of subjects. All of these subjects with reduced or absent leg blood pressure also had obliteration of the femoral pulse with compression. Systemic arterial blood pressure was not significantly elevated by successful aortic occlusion. Discomfort with the manoeuvre was significantly increased (P < 0.05) in the group of subjects that had successful aortic occlusion.

It is recommended that external aortic compression be considered in severe life-threatening postpartum haemorrhage, particularly during stabilisation or transport of the patient. This simple manoeuvre may be used as an adjunct to other measures and could prove of benefit, especially in locations or situations where advanced medical assistance is geographically or temporally removed.
A Double-blind Comparison of Vecuronium Administered by the Springfusor® Infusion Device to Vecuronium by Intermittent Bolus Injection in Critically Ill Adult Patients
Authors: Freebairn R. , Joynt G. M. , Lipman J. , Bothma P. A.
Published: January 2019

To evaluate the Springfusor® infusion device for clinical use in an Intensive Care Unit and to compare the technique of intermittent bolus and constant infusion of muscle relaxants, we undertook a prospective double-blind randomized placebo-controlled study. Twenty critically ill ventilated patients requiring muscle paralysis were investigated. Although we could show no clinical advantage in infusing vecuronium, the Springfusor® provided a more constant level of paralysis compared with hourly bolus doses. The device is robust, easy to use and reduces nursing workload. This may translate into cost-saving improvement in patient care if the Springfusor® is used to provide muscle relaxation, sedation and analgesia.
Release of Inflammatory Mediators in Association with Collection of Wound Drainage Blood during Orthopaedic Surgery
Authors: Arnold J. P. , Haeger M. , Bengtson J. P. , Bengtsson A. , Lisander B.
Published: January 2019

Ten patients undergoing hip replacement surgery were studied regarding activation of complement and leukocytes in association with collection of wound drainage blood. The blood was collected postoperatively but not reinfused due to the possible risks with reinfusion of blood containing inflammatory mediators. Blood samples for analysis of complement activation (TCC), leukocyte activation (PMN elastase) and cytokines (Interleukin-6) were drawn preoperatively from the patients. Blood samples were also drawn intraoperatively from the wound. Samples were also drawn from the collected wound drainage blood, before and after blood was passed through a microporous filter. There were elevated concentrations of TCC, PMN elastase and IL-6 in the collected wound drainage blood before and after the filter. The filtration did not significantly reduce the concentrations of these factors. In the wound blood the concentrations were higher compared to those found in the systemic blood preoperatively, but lower compared to concentrations found in the collected drainage blood. The study demonstrates that the collection of wound drainage whole blood is associated with activation of complement, release of PMN elastase and cytokines.
Quantitative Measurement of Nasal Production of Nitric Oxide in Awake Humans
Authors: Jenkins I. R. , Langlois D.
Published: January 2019

The aim of this study was to determine, quantitiatively, the production of nitric oxide (NO) in the nose and nasopharynx. Subjects were instructed to perform a Valsalva manoeuvre with their mouth open as gas was aspirated from a closely fitting nasal CPAP mask by a chemiluminescence analyser (Sievers 270B, Sievers Instrument Corp. Boulder, Colorado, U.S.A.). Room air was free to flow in through the mouth and out through the nose and hence to the analyser. The manoeuvre was continued until a smooth plateau of at least 20 seconds in duration was achieved on a chart recorder. The mean plateau concentrations were 176 (±39.6) parts per billion (ppb) for males and 135.8 (±24.4) ppb for females. The mean male production of NO was 15.8 nanomol/min which was significantly different from that of females of 12.5 nanomol/min (Mann-Whitney U Test; P < 0.01). By measuring the concentration of NO in gas aspirated from the nose during Valsalva manoeuvre, we excluded the respiratory tract below the glottis from our sampling and as such results represent the portion of NO produced in the nose and nasopharynx. These findings suggest that nasally produced NO is produced in sufficient quantities to act as a continuous pulmonary vasodilator, being inspired preferentially into areas of greatest ventilation, thus perhaps acting to continually match ventilation to perfusion.
Limited Usefulness of Urinary Dipsticks to Screen Out Catheter-associated Bacteriuria in ICU Patients
Authors: Mimoz O. , Bouchet E. , Edouard A. , Costa Y. , Samii K.
Published: January 2019

The use of urinary dipsticks to screen out sterile urine specimens was investigated in catheterized ICU patients. During a three-month period, each urine sample quantitatively cultured was concurrently tested at the bedside with a dipstick. A total of 102 urine samples taken from 43 patients were analysed. Thirty-eight of them showed bacterial or yeast growths (incidence rate, 37%). The negative predictive value of the leukocyte esterase pad and/or the nitrate test pad to screen out sterile urine samples was 81%, indicating that dipsticks cannot routinely be proposed to select catheterized ICU patients for quantitative culture of urine.
The Development of Hypercoagulability State, as Measured by Thrombelastography, Associated with Intraoperative Surgical Blood Loss
Authors: Ng K. F. J. , Lo J. W. R.
Published: January 2019

Thrombelastographic evidence of hypercoagulability, including shortening of r-time (P< 0.01); shortening of k-time (P<0.01); and widening of trace angle (P<0.01) were observed in a group of 21 Chinese surgical patients when (a) the amount of blood loss was at an estimated 10% of total blood volume and (b) the amount of blood loss was at an estimated 15% of blood volume. The amount of blood loss was documented by haemoglobin measurements. No evidence of hypercoagulability was observed at around one hour into the operation in the absence of bleeding. We conclude that a mild to moderate degree of surgical blood loss with haemodilution is associated with the development of hypercoagulability as measured by thrombelastography. Further studies looking at the thrombebolic outcome in such groups of patients is warranted. It is also suggested that caution should be exercuised in the use of intraoperative isovolaemic haemoldilution until the phenomenon is further investigated.
Oral Tenoxicam for Peripheral Orthopaedic Surgery: A Pharmacokinetic Study
Authors: Blake D. W. , Bjorksten A. R. , Libreri F. C.
Published: January 2019

Non-steroidal anti-inflammatory drugs (NSAIDs) provide effective analgesia after orthopaedic surgery and reduce opioid requirements. The need for parenteral NSAIDs with peripheral surgery is controversial. In this study 10 patients were treated with oral tenoxicam 20 mg preoperatively, and at 4 hours and 28 hours after knee ligament reconstruction surgery. Plasma concentrations of tenoxicam, an NSAID with a long elimination half-life, were measured for 10 days. All patients received patient-controlled intravenous morphine postoperatively, which delayed absorption of the second and third tenoxicam doses. However, plasma concentrations of tenoxicam were achieved and maintained for the five-day surgical admission above the level considered to produce effective analgesia. Oral analgesic administration is a simple and feasible option in the perioperative period.
Polyurethane Central Venous Catheters, Hydrochloric Acid and 70% Ethanol: A Safety Evaluation
Authors: McHugh G. J. , Wild D. J. C. , Havill J. H.
Published: January 2019

Three groups of polyurethane central venous catheters (CVC) were infused daily for twenty days with 0.1 normal hydrochloric acid, 70% ethanol and normal saline (control) respectively to look for any changes in microscopic structural integrity.

A 1 cm segment was cut from the distal end of each CVC daily. All sections were examined in a scanning electron microscope, looking for evidence either of damage to the lumen surface or of wall thinning.

No significant damage to the lumen surfaces was observed with either treatment. Sporadic fine surface-pitting appeared late in the study without any clear temporal or treatment-related pattern. The mean CVC wall thickness did not change significantly over the study period (P=0.15). Qualitative softening of ethanol treated catheters was observed, and this finding limits the recommendations for the use of ethanol.

0.1N HCl does not compromise the structural safety of the catheters, and its use should be considered when polyurethane CVC become occluded.
Plasma Lignocaine Concentration following Nebulization for Awake Intubation
Authors: Parkes S. B. , Butler C. S. , Muller R.
Published: January 2019

Nebulization of lignocaine is a common technique for preparing the airway prior to awake intubation. The aim of the study was to assay the serum levels of lignocaine.

Ten ASA I volunteers had 6 mg/kg of 10% lignocaine solution nebulized via facemask. Blood assays for peak levels were performed.

Mean peak serum lignocaine level was 0.29 mg/l with a highest measurement of 0.45 mg/l. This peak occurred 30 minutes following commencing nebulization. No subject developed symptoms or signs of lignocaine toxicity.

Peak plasma lignocaine levels were an order of magnitude below the accepted toxic threshold of 5 mg/l. This indicates that supplemental doses of lignocaine via the bronchoscope can be given with safety.
Retrospective Review of 100 Cases of Endoluminal Aortic Stent-Graft Surgery from an Anaesthetic Perspective
Authors: Baker A. B. , Lloyd G. , Fraser T. A. , Bookallil M. J. , Yezerski S. D.
Published: January 2019

One hundred cases of endoluminal aortic stent surgery were retrospectively reviewed and analysed with respect to outcome. The overall mortality rate was consistent with standard rates for open surgical repair. One hundred per cent of patients who developed multiorgan failure died (7), as did 78% of those who developed acute renal failure (9), and 55% of those who had a serum creatinine rise greater than 100 μmol/l (9). Patients given mannitol had an increased incidence of a serum creatinine rise of greater than 100 μmol/l, at 16% versus 4% for those not given mannitol. Patients with documented intra- or postoperative anaemia (Hb ≤80 g/l) had a mortality rate of 22% compared to 5% for non-anaemic patients. The mortality rate increased from 3% to 15% if the procedure took more than four hours.

The anaesthetic requirements for this new type of surgery are outlined and discussed with respect to these results. The surgical technique is summarized.
Continuous Extrapleural Intercostal Nerve Block for Post Thoracotomy Analgesia in Children
Authors: Downs C. S. , Cooper M. G.
Published: January 2019

The safety and efficacy of continuous extrapleural intercostal nerve block has been well established in adults. This review of our initial paediatric experience suggests a role for this technique in children and discusses risks and benefits relative to other forms of regional analgesia for thoracotomy.

Nine children aged one to twelve years received extrapleural infusions of bupivacaine 0.1-0.2% following lateral thoracotomy for lung resection. An extrapleural catheter was placed by the surgeon prior to thoracotomy closure, and correctly positioned under direct vision external to the parietal pleura alongside the vertebral column. An intraoperative loading dose of bupivacaine, 0.25-0.5% (0.28±0.1 ml/kg, mean±SD) was injected so as to raise a bleb under the parietal pleura which spread longitudinally to bathe several intercostal nerves in the paravertebral gutter. The chest wall was then closed. Infusions of bupivacaine were commenced in the recovery room and continued at a constant rate of 0.21±0.09 ml/kg/h for 72±15 hours. The mean dose of bupivacaine was 284±97 μg/kg/h. Patients also received standard analgesia as an intravenous morphine infusion (10-50 μg/kg/h), or patient-controlled analgesia. Nursing staff were specifically instructed not to alter their usual management of variable rate morphine infusions which are titrated to adequate analgesia.

Morphine requirements in the first 48 postoperative hours remained less than 30 μg/kg/h, oral fluids were well tolerated after 31.2±19.1 hours, nasogastric tubes were removed at 16.7±11.2 hours. Postoperative nausea and vomiting and respiratory depression were not observed in any patient and all were able to comply with physiotherapy. There were no complications of catheter placement or bupivacaine administration.

Our initial experience suggests that this is a safe technique which minimizes complementary opioid administration and provides adequate analgesia for children postthoracotomy for lung resection.
Induction of Anaesthesia with Sevoflurane, Preprogrammed Propofol Infusion or Combined Sevoflurane/Propofol for Laryngeal Mask Insertion: Cardiovascular, Movement and EEG Bispectral Index Responses
Authors: Blake D. W. , Hogg M. N. , Hackman C. H. , Pang J. , Bjorksten A. R.
Published: January 2019

Inhalation induction with sevoflurane was compared with propofol or sevoflurane/propofol in 60 unpremedicated adults. Target concentrations for the three groups (with 60% nitrous oxide) were 3% end-tidal sevoflurane, 12 mg/l propofol and 1.5% sevoflurane/6 mg/l propofol respectively, prior to insertion of a laryngeal mask airway (LMA) at 10 minutes. Induction of anaesthesia was satisfactory in each group, but movement response to LMA insertion was observed in 20 patients (least in the sevoflurane group). Cardiovascular responses were similar except for a lower heart rate in the sevoflurane group. EEG bispectral index suggested a greater depth of anaesthesia in the inhalation induction group. A bispectral index of 60 separated patients responding to LMA insertion from nonresponders (P=0.006), and had a sensitivity of 68% and specificity 70%. Movement response was not predicted by cardiovascular changes.