The prediction of difficult intubation in obese patients was investigated by co-estimating the degree of visibility of oropharyngeal structures in conjunction with the respective body mass index. Data were collected prospectively in a series of 1833 consecutive adult patients. Body mass index (BMI) in kg m-2 was used as a measure of obesity (morbid: > 40, moderate: 30-40, no obesity: < 30). The oropharyngeal class findings were assessed using the original methodology as well as by a modification requiring the tongue to be pulled forward by the examiner. Difficult intubation was defined as inadequate exposure of the glottis by direct laryngoscopy. Both oropharyngeal class methodologies were of equal sensitivity, whereas the modified technique presented a significantly higher positive predictive value (50.0% vs. 37.2%, P < 0.01). Statistical analysis revealed an increased risk of difficult laryngoscopy among obese patients compared with subjects with normal body mass index (20.2% vs. 7.6%, P < 0.001). When obesity is estimated with respect to oropharyngeal class the positive predictive value is greatly improved (66.7% vs. 20.2%, P < 0.001). We conclude that obesity which is associated with a disproportionately large base of the tongue, is a predisposing factor for difficult laryngoscopy.

The incidence of difficulty in tracheal intubation in the presence of goiter was investigated. Data were collected in a series of 4742 consecutive adult patients undergoing general anesthesia. The prevalence of goiter was 6.8%. Fifteen anesthesiologists performed the preoperative airway assessment using standardized guidelines. Seven individual risk factors were correlated with the potential for difficult tracheal intubation. Whenever evidence of goiter or airway pathology was observed, the evaluation was completed by indirect laryngoscopy and radiologic examination to establish the presence of any anatomical deviation. Difficult intubation was defined as inadequate exposure of the glottis by direct laryngoscopy. There was no difference in probability of difficulty in tracheal intubation between patients who presented for thyroidectomy and patients with goiter estimated as a random finding. Statistical analysis revealed an increased risk of difficult intubation amongst goiter patients compared with patients with no evidence of any risk factor (6.8% vs 0.9%, P < 10(-8), relative risk = 7.4). We conclude that goiter, when accompanied by airway deformity, constitutes an aggravating factor for difficult intubation.

We suggest that cryoanalgesia be considered as a simple, safe, inexpensive, long-term form of post-thoracotomy pain relief. Cryoanalgesia effectively restores FEV1 values at the second postop month.

Background Postoperative pulmonary complications (PPC) may result in longer duration of in-hospital stay and even mortality. Both thoracic surgery and intraoperative mechanical ventilation settings add considerably to the risk of PPC. It is unclear if one-lung ventilation (OLV) for thoracic surgery with a strategy of intraoperative high positive end-expiratory pressure (PEEP) and recruitment maneuvers (RM) reduces PPC, compared to low PEEP without RM. Methods PROTHOR is an international, multicenter, randomized, controlled, assessor-blinded, two-arm trial initiated by investigators of the PROtective VEntilation NETwork. In total, 2378 patients will be randomly assigned to one of two different intraoperative mechanical ventilation strategies. Investigators screen patients aged 18 years or older, scheduled for open thoracic or video-assisted thoracoscopic surgery under general anesthesia requiring OLV, with a maximal body mass index of 35 kg/m 2 , and a planned duration of surgery of more than 60 min. Further, the expected duration of OLV shall be longer than two-lung ventilation, and lung separation is planned with a double lumen tube. Patients will be randomly assigned to PEEP of 10 cmH 2 O with lung RM, or PEEP of 5 cmH 2 O without RM. During two-lung ventilation tidal volume is set at 7 mL/kg predicted body weight and, during OLV, it will be decreased to 5 mL/kg. The occurrence of PPC will be recorded as a collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion PROTHOR is the first randomized controlled trial in patients undergoing thoracic surgery with OLV that is adequately powered to compare the effects of intraoperative high PEEP with RM versus low PEEP without RM on PPC. The results of the PROTHOR trial will support anesthesiologists in their decision to set intraoperative PEEP during protective ventilation for OLV in thoracic surgery. Trial registration The trial was registered in clinicaltrials.gov ( NCT02963025 ) on 15 November 2016. Electronic supplementary material The online version of this article (10.1186/s13063-019-3208-8) contains supplementary material, which is available to authorized users.

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