Anaesthesia and intensive care
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Anaesth Intensive Care · Jul 2022
Randomized Controlled TrialEffects of an open lung ventilatory strategy on lung gas exchange during laparoscopic surgery.
In general anaesthesia, early collapse of poorly ventilated lung segments with low alveolar ventilation-perfusion ratios occurs and may lead to postoperative pulmonary complications after abdominal surgery. An 'open lung' ventilation strategy involves lung recruitment followed by 'individualised' positive end-expiratory pressure titrated to maintain recruitment of low alveolar ventilation-perfusion ratio lung segments. There are limited data in laparoscopic surgery on the effects of this on pulmonary gas exchange. ⋯ The sevoflurane arterial/alveolar partial pressure ratio and alveolar deadspace fraction were unchanged from baseline and remained similar between groups (mean (standard deviation) control group = 0.754 (0.086) versus intervention group = 0.785 (0.099), P = 0.319), while the arterial oxygen partial pressure/fractional inspired oxygen concentration ratio was significantly higher in the intervention group at the second timepoint (control group median (interquartile range) 288 (234-372) versus 376 (297-470) mmHg in the intervention group, P = 0.011). There was no difference between groups in the sevoflurane consumption rate. The efficiency of sevoflurane uptake is not improved by open lung ventilation in laparoscopy, despite improved arterial oxygenation associated with effective and sustained recruitment of low alveolar ventilation-perfusion ratio lung segments.
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Anaesth Intensive Care · Jul 2022
The effects of dantrolene in the presence or absence of ryanodine receptor type 1 variants in individuals predisposed to malignant hyperthermia.
Dantrolene is currently the only drug known to specifically treat malignant hyperthermia (MH) crises. Although dantrolene attenuates Ca2+ disorders by acting mainly on the ryanodine receptor type 1 (RYR1), some patients who manifest MH without RYR1 variants have also been successfully treated with dantrolene. Thus, dantrolene appears to have an inhibitory effect on patients with and without RYR1 variants. ⋯ Dantrolene administration significantly increased the EC50 (P < 0.0001) and decreased the resting [Ca2+]i (P < 0.0001). The inhibitory effects of dantrolene and the presence of RYR1 variants showed no statistically significant interactions related to the EC50 (P = 0.59) and resting [Ca2+]i (P = 0.21). In conclusion, the presence or absence of RYR1 variants does not appear to influence the effect of dantrolene.
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Anaesth Intensive Care · Jul 2022
Case ReportsAirway emergency from megaoesophagus: A rare complication of an adjustable gastric band.
A 77-year-old lady with a laparoscopic adjustable gastric band (LAGB), implanted 12 years earlier for obesity, developed an unusual but almost fatal complication, characterised by dysphonia and stridor within minutes and a tensely swollen anterior neck. The condition mimicked haemorrhage into the subcutaneous tissues of the neck, and the airway was secured with an awake fibreoptic intubation. Subsequent computed tomography imaging of the abdomen and chest revealed megaoesophagus with dilatation up to 7 cm, proximal to the gastric band. ⋯ In patients with LAGB in situ, fluid should be removed from the band for any suspected device-associated symptoms such as severe vomiting, severe gastro-oesophageal reflux or neck swelling and respiratory distress. When there is radiological evidence of gross oesophageal dilatation or a high likelihood of an obstructive pathology at the level of the band, a careful nasogastric tube decompression may also resolve reflux, neck swelling or respiratory distress. A complication associated with LAGB should be considered in a patient with unexplained neck swelling or other features of airway obstruction who has an LAGB in situ.