Dharshi Karalapillai

Inadvertent hypothermia and mortality in postoperative intensive care patients: retrospective audit of 5050 patients

We proposed that many Intensive Care Unit (ICU) patients would be hypothermic in the early postoperative period and that hypothermia would be associated with increased mortality. We retrospectively reviewed patients admitted to ICU after surgery. We recorded the lowest temperature in the first 24 h after surgery using tympanic membrane thermometers. We defined hypothermia as < 36 °C, and severe hypothermia as < 35 °C. We studied 5050 consecutive patients: 35% were hypothermic and 6% were severely hypothermic. In‐hospital mortality was 5.6% for normothermic patients, 8.9% for all hypothermic patients (p < 0.001), and 14.7% for severely hypothermic patients (p < 0.001). Hypothermia was associated with in‐hospital mortality: OR 1.83 for each degree Celsius (°C) decrease (95% CI: 1.2–2.60, p < 0.001). Given the evidence for improved outcome associated with active patient warming during surgery we suggest conducting prospective studies of active warming of patients admitted to ICU after surgery.

Postoperative hypothermia and patient outcomes after major elective non-cardiac surgery.

Using a multicentre adult patient database from Australia and New Zealand, we obtained the lowest and highest temperature in the first 24 h after admission to the intensive care unit after elective non‐cardiac surgery. Hypothermia was defined as core temperature < 36 °C; transient hypothermia as a temperature < 36 °C that was corrected within 24 h, and persistent hypothermia as hypothermia not corrected within 24 h. We studied 50 689 patients. Hypothermia occurred in 23 165 (46%) patients, was transient in 22 810 (45%), and was persistent in 608 (1.2%) patients. On multivariate analysis, neither transient (OR = 1.07, 95% CI 0.96–1.20) nor persistent (OR = 1.50. 95% CI 0.96–2.33) hypothermia was independently associated with increased hospital mortality.

Postoperative hypothermia and patient outcomes after elective cardiac surgery

Hypothermia after elective cardiac surgery is an important physiological abnormality and is associated with increased morbidity and mortality. The Australian and New Zealand intensive care adult patient database was studied to obtain the lowest and highest temperature in the first 24 h after surgery. Hypothermia was defined as core temperature < 36 °C; transient hypothermia as temperature < 36 °C that was corrected within 24 h; and persistent hypothermia as hypothermia that was not corrected within 24 h. Hypothermia occurred in 28 587 out of a total of 43 158 consecutive patients (66%) and was persistent in 111 (0.3%). Transient hypothermia was not independently associated with increased hospital mortality (OR = 0.9, 95% CI 0.8–1.1), whereas persistent hypothermia was associated with markedly increased risk of death (OR = 6.3, 95% CI = 3.3–12.0). Hypothermia is common in postoperative cardiac surgery patients during the first 24 h after ICU admission but, if transient, is not independently associated with an increased risk of death.

A review of video laryngoscopes relevant to the intensive care unit

The incidence of difficult direct intubation in the intensive care unit (ICU) is estimated to be as high as 20%. Recent advances in video-technology have led to the development of video laryngoscopes as new intubation devices to assist in difficult airway management. Clinical studies indicate superiority of video laryngoscopes relative to conventional direct laryngoscopy in selected patients. They are therefore an important addition to the armamentarium of any clinician performing endotracheal intubation. We present a practical review of commonly available video laryngoscopes with respect to design, clinical efficacy, and safety aspects relevant to their use in the ICU.

The Melbourne epidemic thunderstorm asthma event 2016: an investigation of environmental triggers, effect on health services, and patient risk factors

BACKGROUND A multidisciplinary collaboration investigated the worlds largest, most catastrophic epidemic thunderstorm asthma event that took place in Melbourne, Australia, on Nov 21, 2016, to inform mechanisms and preventive strategies. METHODS Meteorological and airborne pollen data, satellite-derived vegetation index, ambulance callouts, emergency department presentations, and data on hospital admissions for Nov 21, 2016, as well as leading up to and following the event were collected between Nov 21, 2016, and March 31, 2017, and analysed. We contacted patients who presented during the epidemic thunderstorm asthma event at eight metropolitan health services (each including up to three hospitals) via telephone questionnaire to determine patient characteristics, and investigated outcomes of intensive care unit (ICU) admissions. FINDINGS Grass pollen concentrations on Nov 21, 2016, were extremely high (>100 grains/m3). At 1800 AEDT, a gust front crossed Melbourne, plunging temperatures 10°C, raising humidity above 70%, and concentrating particulate matter. Within 30 h, there were 3365 (672%) excess respiratory-related presentations to emergency departments, and 476 (992%) excess asthma-related admissions to hospital, especially individuals of Indian or Sri Lankan birth (10% vs 1%, p<0·0001) and south-east Asian birth (8% vs 1%, p<0·0001) compared with previous 3 years. Questionnaire data from 1435 (64%) of 2248 emergency department presentations showed a mean age of 32·0 years (SD 18·6), 56% of whom were male. Only 28% had current doctor-diagnosed asthma. 39% of the presentations were of Asian or Indian ethnicity (25% of the Melbourne population were of this ethnicity according to the 2016 census, relative risk [RR] 1·93, 95% CI 1·74-2·15, p <0·0001). Of ten individuals who died, six were Asian or Indian (RR 4·54, 95% CI 1·28-16·09; p=0·01). 35 individuals were admitted to an intensive care unit, all had asthma, 12 took inhaled preventers, and five died. INTERPRETATION Convergent environmental factors triggered a thunderstorm asthma epidemic of unprecedented magnitude, tempo, and geographical range and severity on Nov 21, 2016, creating a new benchmark for emergency and health service escalation. Asian or Indian ethnicity and current doctor-diagnosed asthma portended life-threatening exacerbations such as those requiring admission to an ICU. Overall, the findings provide important public health lessons applicable to future event forecasting, health care response coordination, protection of at-risk populations, and medical management of epidemic thunderstorm asthma. FUNDING None.