Phoebe Mainland

Capnometry, the measurement of respiratory carbon dioxide, is regarded as a highly recommended safety technology in intubated and nonintubated sedated and/or anesthetized patients. Its utility includes confirmation of initial and ongoing placement of an airway device as well as in detecting gas exchange, bronchospasm, airway obstruction, reduced cardiac output, and metabolic changes. The utility applies prehospital and throughout all phases of inhospital care. Unfortunately, capnometry devices are not readily available in many countries, especially those that are resource-limited. Constraining factors include cost, durability of devices, availability of consumables, lack of dependable power supply, difficulty with cleaning, and maintenance. There is, thus, an urgent need for all stakeholders to come together to develop, market, and distribute appropriate devices that address costs and other requirements. To foster this process, the World Federation of Societies of Anaesthesiologists (WFSA) has developed the "WFSA-Minimum Capnometer Specifications 2021." The intent of the specifications is to set the minimum that would be acceptable from industry in their attempts to reduce costs while meeting other needs in resource-constrained regions. The document also includes very desirable and preferred options. The intent is to stimulate interest and engagement among industry, clinical providers, professional associations, and ministries of health to address this important patient safety need. The WFSA-Minimum Capnometer Specifications 2021 is based on the International Organization for Standardization (ISO) capnometer specifications. While industry is familiar with such specifications and their presentation format, most clinicians are not; therefore, this article serves to more clearly explain the requirements. In addition, the specifications as described can be used as a purchasing guide by clinicians.

A tracheoesophageal voice prosthesis facilitates speech rehabilitation after laryngectomy (1,2). We describe the anesthetic management of a patient who required repair of a large tracheoesophageal fistula around the voice prosthesis. The requirements for access to the upper trachea excluded the use of a tracheotomy tube. Our technique of total intravenous anesthesia, spontaneous ventilation, and endotracheal O 2 insufflation provided excellent operating conditions while ensuring adequate anesthesia depth, oxygenation, and patient safety.

The problems and difficulties associated with the donating of medical drugs and equipment especially during times of disaster are discussed. The core principles of donation as laid down by the World Health Organization (WHO) need to be followed for proper use of such donations.

A case of exertion-induced heatstroke which illustrates the multiple complications of hyperthermia, including jaundice, coagulopathy and cardiac abnormalities, is reported. The need to increase public awareness of the danger of hyperthermia, and of preventive and first-aid measures, is emphasized.

Wrong route medication errors due to tubing misconnections are potentially life-threatening complications that have been made possible by the universal use of the Luer connector. The new International Organization of Standardization standards for small bore connectors, ISO 80369 series, have been developed to reduce the risk of these types of erroneous connections. Tubing connectors for different routes of clinical application will contain differently designed connectors that are physically incompatible. However, design and manufacturing standards have progressed slowly, and clinical roll-outs have been delayed, despite the implementation of California laws to promote their use. We are currently in a state of transition where new connectors for enteral and neuraxial use will be entering the clinical market in the next few years, and increasing use will identify additional patient safety concerns.

1. Lancet. 1997 Mar 29;349(9056):921. Stroke following central venous cannulation. Mainland PA, Tam WH, Law B, Ngan Kee W. Comment in: Lancet. 1997 Jun 7;349(9066):1699. PMID: 9093255 [PubMed - indexed for MEDLINE]. Publication Types: Case Reports; Letter. ...

Lidocaine instilled onto to the back of the tongue of a supine subject and aspirated has been reported to provide effective topical anesthesia of the airway. The purpose of this study was to observe endoscopically the fate of lidocaine so instilled and document the efficacy of anesthesia for awake fibreoptic intubation. In Part I of the study, a fibreoptic bronchoscope was positioned in the pharynx of three volunteers lying supine and the route followed by tinted lidocaine solution instilled onto the back of the protruded tongue during mouth breathing was observed. In Part 2, the airway of 39 patients requiring awake fibreoptic intubation was anesthetized by having them gargle twice with 5 ml lidocaine 2%, followed by instillation of 0.2 ml-kg(-1) or 20 ml lidocaine 1.5% (whichever was less) onto the dorsum of their tongues as described above. The efficacy of anesthesia was scored by the patient reaction (coughing or gagging) to instrumentation in the pharynx, at the glottis, and in the trachea; to passage of the tracheal tube into the trachea; and to the presence of the tube in the trachea. Lidocaine instilled on to the back of the tongue was swallowed initially but ultimately pooled in the pharynx and was aspirated. In all patients the trachea was intubated without requiring supplemental lidocaine, and all but one patient tolerated the tracheal tube in situ. A combination of lidocaine gargles and lidocaine instilled on to the back of the tongue and aspirated provides effective anesthesia of the pharynx, larynx, and trachea for awake fibreoptic intubation.

Anesthetic requirements for inhalational agents are decreased during pregnancy, but there are no data regarding requirements for intravenous agents. The quantal dose-response curves for thiopental were calculated for 70 nonpregnant women having gynecologic surgery and for 70 pregnant women of 7-13 weeks' gestation having elective abortions. Groups of 10 patients were given 2, 2.4, 2.8, 3.3, 3.8, 4.5, or 5.3 mg/kg thiopental as a bolus dose during a period of 10 s. Two minutes later, patients were asked to open their eyes as a test for hypnosis. Patients who did not open their eyes were given a 10-s, 50-Hz, 80-mA transcutaneous tetanic electrical stimulus to the ulnar nerve as a test for anesthesia. Purposeful movement indicated that there was no anesthesia. Log dose-response curves for hypnosis and anesthesia were calculated after logit transformation. In the nonpregnant women, the median effective doses (ED50s) (95% confidence interval) for hypnosis and anesthesia were 3.1 (2.8-3.4) mg/kg and 4.9 (4.5-5.4) mg/kg, whereas in the pregnant women the corresponding ED50s were 2.6 (2.3-2.8) mg/kg and 4 (3.7-4.4) mg/kg. In the non-pregnant women, the ED95s (95% CI) for hypnosis and anesthesia were 4.4 (3.9-5.4) mg/kg and 6.4 (5.7-7.9) mg/kg, whereas in the pregnant women the corresponding ED95s were 3.7 (3.3-4.5) mg/kg and 5.2 (4.7-6.3) mg/kg. The pregnant to nonpregnant relative median potency (95% CI) ratio for hypnosis was 0.83 (0.67-0.96) and for anesthesia it was 0.82 (0.62-0.94). The dose of thiopental for hypnosis was 17% less and that for anesthesia was 18% less in pregnant women of 7-13 weeks' gestation compared with that in nonpregnant women.