Small tidal volume ventilation using a zero deadspace tracheal tube.

The zero deadspace tracheal tube (ZEDS-TT) is a double-lumen endobronchial tube with a truncated bronchial limb. Functionally it is unrelated to the familiar endobronchial tube used in lung isolation surgery. It is placed in the same position as a regular tracheal tube and, by means of special connectors, one limb is used for inspiration and the other for expiration, thereby greatly reducing anatomical and apparatus deadspace. In this study, we have compared respiratory and ventilatory effects of reduction of tidal volume (VT) via a single-lumen tracheal tube and the ZEDS-TT during controlled ventilation with a Siemens Elema 900C Servo ventilator. Eleven consenting adult patients (ASA I and II) undergoing elective peripheral surgery were studied. Starting at a VT value of 10 ml kg-1, data were recorded for each tube type. VT was reduced by 2.5 ml kg-1 every 10 min and stabilized data recorded. Minute volume was kept constant by increasing ventilatory frequency at each reduction in VT. We found that the ZEDS-TT produced a significant reduction in PaCO2 and airway pressure for any VT used, while maintaining oxygenation.

Anaesthetic breathing circuit obstruction due to blockage of tracheal tube connector by a foreign body--two cases.

Two cases are presented which illustrate the disastrous consequences possible when an anaesthetic breathing circuit is obstructed by a foreign body. Despite reports of previous similar cases, work practices and equipment manufacture or design continue to allow for such events to occur. The importance of both pre-anaesthetic testing of the entire circuit including attachments such as the tracheal tube connector and filters, and the removal of these parts should obstruction occur, is emphasised. Use of "clear" transparent breathing circuit components and opaque or brightly coloured packaging and caps which could potentially cause obstruction should decrease the incidence and facilitate the diagnosis of this problem.

Rapid tracheal intubation with propofol, alfentanil and a standard dose of vecuronium.

We studied 60 ASA I patients with Mallampati grade 1 airways to compare emergency intubating conditions with either alfentanil 20 micrograms kg-1, propofol 2.5 mg kg-1 and vecuronium 0.1 mg kg-1, or with thiopentone 5 mg kg-1 and suxamethonium 1 mg kg-1. Ease of laryngoscopy, vocal cord status and cough response were graded. The trachea of all patients was intubated; 83% of patients in the alfentanil-propofol-vecuronium group and 86% in the thiopentone-suxamethonium group were considered to have satisfactory intubating conditions at 60 s. We conclude that the combination of alfentanil 20 micrograms kg-1, propofol 2.5 mg kg-1 and vecuronium 0.1 mg kg-1 provided adequate conditions for rapid tracheal intubation.

Tension pneumoperitoneum aggravating respiratory failure. A case report.

A case of tension pneumoperitoneum secondary to barotrauma is reported. Any patient needing high pressures for ventilation and oxygenation is prone to this complication. The important respiratory and haemodynamic implications are discussed. It is suggested that drainage of a tension pneumoperitoneum is easy and safe and has major beneficial effects on the respiratory and cardiovascular systems.

Comparison of disease severity scoring systems in septic shock.

OBJECTIVE: To compare six disease severity scoring systems as predictors of mortality in septic shock when used in the first 24 hrs of diagnosis. The six scoring systems tested were: Multiorgan Failure; the Acute Organ System Failure; the Acute Physiology and Chronic Health Evaluation (APACHE II); the Multisystem Organ Failure scoring system; the Mortality Prediction Model; and the grading of sepsis. DESIGN: Retrospective, case series, consecutive sample. SETTING: Adult ICUs of three teaching hospitals. PATIENTS: Seventy-one patients from 12 to 84 yrs, fulfilling specific criteria for the diagnosis of septic shock, who were admitted to the ICU during 15 consecutive months. MEASUREMENTS AND MAIN RESULTS: The Multiorgan Failure scoring system, Acute Physiology and Chronic Health Evaluation (APACHE II), and Acute Organ System Failure scoring system were found, with our modifications, to be statistically significant predictors of mortality. Predictive data for these three scoring systems were as follows: Multiorgan Failure scoring system p = .008, mean number of points of survivors 5.2 +/- 1.5 (SD), mean number of points of nonsurvivors 6.3 +/- 1.5; APACHE II p = .013, mean number of points of survivors 21.1 +/- 5.9, mean number of points of nonsurvivors 24.6 +/- 6.0; and Acute Organ System Failure scoring system p = .011. None of the other three scoring systems showed significant predictive ability: Multisystem Organ Failure scoring system p = .072, Mortality Prediction Model p = 0.091, and the grading of sepsis p = .27. There was a significant (p = .004) difference in the survival rate of the three hospitals. CONCLUSION: The Multiorgan Failure scoring system, APACHE II, and the Acute Organ System Failure scoring system, with minor modifications, were found to be useful prognostic tools for patients with septic shock and allowed us to compare the performance and treatment programs of different ICUs.

The response of animals to suxamethonium (succinyldicholine) and succinylmonocholine.

The time which elapses before cessation of breathing, and blood pressure and blood gas changes after the intramuscular administration of suxamethonium, or a mixture of suxamethonium and hexamethonium, is compared in immobilised African elephants (Loxodonta africana) and buffaloes (Syncerus caffer). In addition, the respiratory responses of elephants and other animals to intravenous administration of suxamethonium and succinylmonocholine are reported on, as are the effects of darting animals with succinylmonocholine. The results show that respiration is affected in a similar fashion in all species investigated. However, the characteristic gradual decrease in respiratory rate seen in elephants during culling, using suxamethonium, resembles the effects observed when succinylmonocholine is administered. It is suggested that elephants are killed by this first breakdown product of suxamethonium during culling and/or that unique acetylcholine receptors may be involved.

Blood constituent responses of animals culled with succinyldicholine and hexamethonium.

Blood constituent responses of elephants and buffaloes culled in the Kruger National Park, using a mixture of succinyldicholine and hexamethonium, were compared to those of animals culled with succinyldicholine only. The results show a decreased physiological response in the animals culled with the mixture, characterised by lower total catecholamine, cortisol and glucose concentrations. Neither a delay of up to 30 min in obtaining blood samples from culled animals, nor a delay of up to 30 min in processing samples obtained immediately after cessation of respiration, gave any significant difference in the blood constituents which were measured.

Pulmonary aspergilloma--indications for surgical intervention. An analysis of 22 cases.

Surgical resection of aspergillomas has generally been associated with excess mortality and morbidity; 22 patients who had a resection of complicated mycetomas were studied retrospectively. Indications for surgery were serious haemoptysis (14), massive haemoptysis (6), and recurrent infection (2). Extrapleural pneumonectomy was required in 9 patients and extrapleural lobectomy in 12; thoracoplasty alone was done in 1 patient. There was 1 hospital death (4.5%); 4 patients developed postoperative empyemas (18%), 2 with associated bronchopleural fistulas. Two further patients (9%) had stable postresectional spaces. Surgery for complicated aspergilloma was associated with significant postoperative morbidity.

Comparison of the effects of atropine and glycopyrrolate on pulmonary mechanics in patients undergoing fiberoptic bronchoscopy.

The effects of atropine and glycopyrrolate on forced vital capacity (FVC), forced expired volume in one second (FEV1), the FEV1/FVC ratio, and peak expiratory flow (PFL) were compared in 44 patients undergoing fiberoptic bronchoscopy under general anesthesia. Both anticholinergic agents improved pulmonary function equally before general anesthesia, but in both groups there was a small and again equal deterioration in pulmonary function after the procedure. The protective effects of the two drugs were not significantly different. Because of the lower incidence of undesirable side effects, glycopyrrolate is recommended as the anticholinergic agent of choice for bronchoscopy.

Pulmonary resection in the prone position for suppurative lung disease in children.

Lung resection for suppurative inflammatory disease is hazardous in children whose small airway diameter precludes the use of standard methods of bronchial separation. A prospective evaluation of the prone position for thoracotomy in 17 children referred for operation with severe inflammatory disease was done. Bronchography showed whole lung bronchiectasis eight, destroyed lung in three, and lobar bronchiectasis five. Pulmonary resections performed with the child prone included left pneumonectomy (nine), right pneumonectomy (four), lingulectomy with lower lobectomy (two), and other lobectomy (two). No endobronchial or intrapleural spillage occurred. One child required reexploration for bleeding and one child developed a postoperative empyema that ultimately caused death. The remaining 16 children were discharged within 8 days of operation, and follow-up of 1 to 18 months records favorable progress.

Hypokalaemia after suxamethonium administration.

The effect of suxamethonium on serum potassium levels was studied in 20 black patients undergoing emergency surgery. All patients were resuscitated pre-operatively to achieve a normal pH (range 7.35-7.45), normal electrolyte values (potassium range 3.5-4.5 mmol/l), and an adequate circulating blood volume using the criteria of systolic blood pressure in excess of 100 mmHg and a central venous pressure maintained at more than 2 cm H2O. Suxamethonium (approximately 0.8 mg/kg) was administered during a standard rapid intubation sequence for the induction of anaesthesia. In the adequately resuscitated emergency patient an induced respiratory alkalosis may prevent the rise in serum potassium previously reported with the use of suxamethonium.

Comparison of nalbuphine and pethidine for the relief of pain after caesarean section.

Nalbuphine (Nubain; Du Pont) 0.2 mg/kg (a new semisynthetic agonist-antagonist opioid) was compared with pethidine 0.75 mg/kg intravenously for analgesia after caesarean section in 70 patients. Statistical analysis of data showed that there was equivalence for analgesia, respiratory rate, cardiovascular parameters, side-effects and patient acceptance between the two drugs.

Anaesthetic scavenger evaluation in the laboratory.

A method of testing scavenging devices in isolation in a test box was developed. The rate of pollution in the box was measured with varying ventilating and suction conditions which allowed a leak index to be calculated so that the efficacy of commercially available scavengers could be compared to the system without a scavenger, and to each other. The BOC scavenger tested reduced pollution but was less efficient at low suction rates. For this scavenger the suction rate should be greater than 20 litre min-1.

Neurolept anaesthesia using etomidate as the hypnotic agent.

A technique of neurolept anaesthesia using etomidate (Hypnomidate; Janssen) instead of nitrous oxide is described in which a continuous infusion of 1 mg/kg/h is used to supplement droperidol, fentanyl and alcuronium. This totally intravenous technique eliminates theatre pollution, may offer haemodynamic stability and may be of use in patients with raised intracranial pressure. Pain on injection and muscle movements which occur with etomidate administration do not detract from the value of this technique.

Etomidate infusion for resection of phaeochromocytoma. A report of 2 cases.

Anaesthesia in patients undergoing resection of phaeochromocytomas is associated with fluctuations in blood pressure and cardiac dysrhythmias. Two patients in whom an etomidate (Hypnomidate; Janssen Pharmaceutica) infusion was used as a supplement to droperidol, fentanyl, pancuronium, air and oxygen anaesthesia are described. Cardiovascular stability was well maintained; the advantages of this technique are discussed.