Transnasal Humidified Rapid‐Insufflation Ventilatory Exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways

Emergency and difficult tracheal intubations are hazardous undertakings where successive laryngoscopy–hypoxaemia–re‐oxygenation cycles can escalate to airway loss and the ‘can't intubate, can't ventilate’ scenario. Between 2013 and 2014, we extended the apnoea times of 25 patients with difficult airways who were undergoing general anaesthesia for hypopharyngeal or laryngotracheal surgery. This was achieved through continuous delivery of transnasal high‐flow humidified oxygen, initially to provide pre‐oxygenation, and continuing as post‐oxygenation during intravenous induction of anaesthesia and neuromuscular blockade until a definitive airway was secured. Apnoea time commenced at administration of neuromuscular blockade and ended with commencement of jet ventilation, positive‐pressure ventilation or recommencement of spontaneous ventilation. During this time, upper airway patency was maintained with jaw‐thrust. Transnasal Humidified Rapid‐Insufflation Ventilatory Exchange (THRIVE) was used in 15 males and 10 females. Mean (SD [range]) age at treatment was 49 (15 [25–81]) years. The median (IQR [range]) Mallampati grade was 3 (2–3 [2–4]) and direct laryngoscopy grade was 3 (3–3 [2–4]). There were 12 obese patients and nine patients were stridulous. The median (IQR [range]) apnoea time was 14 (9–19 [5–65]) min. No patient experienced arterial desaturation < 90%. Mean (SD [range]) post‐apnoea end‐tidal (and in four patients, arterial) carbon dioxide level was 7.8 (2.4 [4.9–15.3]) kPa. The rate of increase in end‐tidal carbon dioxide was 0.15 kPa.min^?1. We conclude that THRIVE combines the benefits of ‘classical’ apnoeic oxygenation with continuous positive airway pressure and gaseous exchange through flow‐dependent deadspace flushing. It has the potential to transform the practice of anaesthesia by changing the nature of securing a definitive airway in emergency and difficult intubations from a pressured stop–start process to a smooth and unhurried undertaking.     

A derived and validated score to predict prolonged mechanical ventilation in patients undergoing cardiac surgery

Objectives

Prolonged mechanical ventilation after cardiac surgery imposes a significant burden on the patient in terms of morbidity as well as a financial burden on the hospital. We undertook a retrospective analysis of 2 prospectively collected databases developed in tertiary cardiac care centers to derive and validate a risk index predicting prolonged mechanical ventilation after cardiac surgery.

不同头颈位置时i-gel喉罩对全麻手术患者气道密封压和通气效果的影响

目的 探讨不同头颈位置时i-gel喉罩对全麻手术患者气道密封压(OLP)和通气效果的影响.方法 择期全麻手术患者30例,性别不限,年龄32 ～ 64岁,BMI 18 ～ 30 kg/m2,ASA分级Ⅰ或Ⅱ级.麻醉诱导后,采用单手旋转盲插法置人i-gel喉罩,置入成功后行机械通气.分别在头颈正中位、俯屈位、仰伸位及侧旋位(右侧)时记录OLP、呼出潮气量(VTE)、气道峰压(PPeak)和通气效果,并采用纤维支气管镜观察咽部解剖结构显露情况.结果 与头颈正中位比较,头颈俯屈位时OLP和PPeak升高,VTE降低,头颈仰伸位时OLP和PPeak降低,VTE升高,头颈俯屈位时通气效果较差(P＜0.05),不同头颈位置时咽部解剖结构显露程度差异无统计学意义(P＞0.05).结论 i-gel喉罩用于全麻手术患者时应避免头颈俯屈位.     

校正体重设置肥胖患者全身麻醉机械通气潮气量的可行性

目的 评价校正体重设置肥胖患者全身麻醉机械通气潮气量的可行性.方法 肥胖患者60例,拟全麻下择期手术,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将其分成3组(n=20):实际体重潮气量组(A组)、理想体重潮气量组(I组)和校正体重潮气量组(C组).麻醉诱导后气管插管,根据相应体重水平,按8 ml/kg设置机械通气初始潮气量,呼吸频率15次/min.于机械通气开始后10min记录气道峰压(Ppeak)、气道平台压(Pp1at)和气道阻力(Raw),机械通气30 min时采集动脉血行血气分析,并记录PaO2、PaCO2及患者需调整潮气量的发生情况.结果 与A组比较,I组和C组PaCO2升高,Ppeak、Pplat、Raw降低(P＜0.01);与I组比较,C组PaCO2降低,Ppeak、Pplat、Raw升高(P＜0.01或0.05);患者需调整潮气量的发生率,C组为0,而A组(95％)和I组(80％)明显升高(P＜0.01).结论 肺功能正常的肥胖患者全身麻醉机械通气时,根据校正体重8 ml/kg设置潮气量是可行的.     

Efficacy of maintaining low-tidal volume mechanical ventilation as compared to resting lung strategy during coronary artery bypass graft cardiopulmonary bypass surgery: A post-hoc analysis of the MECANO trial

Study objectiveTo compare a low-tidal-volume with positive end-expiratory pressure strategy (VENT strategy) to a resting-lung-strategy (i.e., no-ventilation (noV) strategy) during cardiopulmonary bypass for coronary artery bypass graft surgery on the incidence of postoperative pulmonary complications.DesignPost-hoc analysis of the MECANO trial which was a prospective single-center, blind, randomized, parallel-group controlled trial.SettingTertiary care cardiac surgery center.PatientsPatients who underwent isolated on-pump coronary bypass surgery were randomized either to VENT or noV group.InterventionDuring the cardiopulmonary bypass phase of the cardiac surgery procedure, mechanical ventilation in the VENT group consisted of a tidal volume of 3 mL/kg, a respiratory rate of 5 per minute and a positive end-expiratory pressure of 5 cmH₂O. Patients in the noV group received no ventilation during this phase.MeasurementsPrimary composite outcome combining death, early respiratory failure, ventilation support beyond day 2 and reintubation.Main resultsIn this post-hoc analysis, we retained 725 patients who underwent isolated CABG surgery, from the 1501 patients included in the original study. There were 352 in the VENT group and 373 patients in the noV group. Post-hoc comparison yielded no differences in baseline characteristics between these two groups. The primary outcome occurred less frequently in the VENT group than in the noV group, with 44 (12.5%) and 76 (20.4%) respectively (odds-ratio (OR) = 0.56 (0.37–0.84), p = 0.004). There were fewer early respiratory dysfunctions and prolonged respiratory support in the VENT group (respectively, OR = 0.34 (0.12–0.96) p = 0.033 and OR = 0.51 (0.27–0.94) p = 0.029). Complications related to mechanical ventilation were similar in the two groups.ConclusionsIn this post-hoc analysis, maintaining low-tidal ventilation compared to a resting-lung strategy was associated with fewer pulmonary postoperative complications in patients who underwent isolated CABG procedures.     

Frailty is associated with morbidity in adults undergoing elective anterior lumbar interbody fusion (ALIF) surgery

Background Context

Prior studies have suggested no significant differences in functional status and postoperative complications of elderly versus nonelderly patients undergoing posterior lumbar interbody fusion; however, similar studies have not been comprehensively investigated in the setting of anterior lumbar interbody fusion (ALIF).

Transnasal humidified rapid‐insufflation ventilatory exchange (THRIVE) vs. facemask breathing pre‐oxygenation for rapid sequence induction in adults: a prospective randomised non‐blinded clinical trial

Transnasal humidified rapid‐insufflation ventilatory exchange (THRIVE) can prolong apnoea time in adults. Therefore, THRIVE used for pre‐oxygenation in rapid sequence induction of anaesthesia could extend safe apnoea time during prolonged laryngoscopy and intubation. In this randomised controlled trial, we compared the lowest peripheral oxygen saturation (SpO₂) during intubation when pre‐oxygenating with either traditional facemask or THRIVE. Eighty adult patients, undergoing rapid sequence induction of anaesthesia for emergency surgery, were randomly allocated to pre‐oxygenation with 100% oxygen with facemask or with THRIVE. Median (IQR [range]) lowest SpO₂ until 1 min after intubation was 99% (97–100 [70–100]%) for the facemask group vs. 99% (99–100 [96–100]%) for the THRIVE group (p = 0.097). Five patients (12.5%) desaturated below 93% when pre‐oxygenated with the facemask vs. none in the THRIVE group (p = 0.019). There were no differences in intubation time or apnoea time between the groups. Median intubation time was 51 (34–66 [22–261]) s in the facemask group vs. 48 (38–63 [10–146]) s in the THRIVE group (p = 0.99). Median apnoea time was 109 (86–142 [37–291]) s and 116 (92–146 [63–249]) s when using facemask and THRIVE, respectively (p = 0.49). No signs of regurgitation of gastric content were detected. The data on desaturation indicate potential benefits of oxygenation with THRIVE for rapid sequence induction compared with facemask pre‐oxygenation.     

A total balanced volume replacement strategy using a new balanced hydoxyethyl starch preparation (6% HES 130/0.42) in patients undergoing major abdominal surgery

BACKGROUND AND OBJECTIVE: The kind of fluid for correcting hypovolaemia is still a focus of debate. In a prospective, randomized, controlled and double-blind study in patients undergoing major abdominal surgery, a total balanced volume replacement strategy including a new balanced hydroxyethyl starch (HES) solution was compared with a conventional, non-balanced fluid regimen. METHODS: In Group A (n = 15), a new balanced 6% HES 130/0.42 was given along with a balanced crystalloid solution; in Group B (n = 15), an unbalanced conventional HES 130/0.42 plus an unbalanced crystalloid (saline solution) were administered. Volume was given when mean arterial pressure (MAP) was <65 mmHg and central venous pressure (CVP) minus positive end-expiratoric pressure (PEEP) level was <10 mmHg. Haemodynamics, acid-base status, coagulation (thrombelastography (TEG)) and kidney function (including kidney-specific proteins, N-acetyl-beta-d-glucosaminidase (beta-NAG) and alpha-1-microglobulin) were measured after induction of anaesthesia, at the end of surgery, 5 and 24 h after surgery. RESULTS: Group A received 3533 +/- 1302 mL of HES and 5333 +/- 1063 mL of crystalloids, in Group B, 3866 +/- 1674 mL of HES and 5966 +/- 1202 mL of crystalloids were given. Haemodynamics, laboratory data, TEG data and kidney function were without significant differences between the groups. Cl- concentration and base excess (-5 +/- 2.4 mmol L-1 vs. 0.4 +/- 2.4 mmol L-1) were significantly higher in patients of Group B than of Group A. CONCLUSIONS: A complete balanced volume replacement strategy including a new balanced HES preparation resulted in significantly less derangement in acid-base status compared with a non-balanced volume replacement regimen. The new HES preparation showed no negative effects on coagulation and kidney function.     

The reinforced laryngeal mask airway (RLMA) protects the airway in patients undergoing nasal surgery — an observational study of 200 patients

PURPOSE: The laryngeal mask airway (LMA) is used in nasal surgery but there is some concern of tracheal or laryngeal contamination with blood and secretions. We have evaluated the ability of the LMA to prevent airway contamination until full emergence from anesthesia. METHODS: Two hundred adults, ASA I-III patients, undergoing nasal surgery under general anesthesia were included in a prospective observational study. A reinforced LMA, sizes 3-5, was used during surgery and removed with its cuff inflated, in recovery, when the patients awoke. The LMA was examined on its laryngeal aspect for contamination of blood and secretions and scored (0-3) independently by two observers according to soiling (score of 0 = no blood; score of 1 = staining on the cuff; score of 2 = staining on the inside of mask; score of 3 = blood in the tube). RESULTS: The contamination scores were [n (%)]: 0 =174 (87%); 1 = 22 (11%); 2 = 4 (2%); 3 = 0 (0%). CONCLUSION: Ninety-eight percent of patients had no or minimal contamination of the LMA. The 2% incidence of grade 2 LMA soiling is low and probably acceptable, since it did not result in symptoms of airway contamination. We suggest that the use of the LMA for nasal surgery may be appropriate.     

6％羟乙基淀粉130／0．4在小儿腹部手术中容量治疗的临床应用

目的 探讨6％羟乙基淀粉130／0．4在小儿腹部手术中容量治疗的应用效果。方法60例拟行腹部手术的患儿随机分为观察组和对照组,每组各30例。观察组术中容量治疗使用6％羟乙基淀粉130／0．4及晶体液;对照组未使用6％HES130／0．4,所使用的晶体液与观察组相同,可选用胶体液为浓缩红细胞。观察两组患儿手术前后心率、血压．总输液量及晶体液、胶体液、浓缩红细胞输入量等。记录观察组因输注6％羟乙基淀粉可能出现的不良反应,如：过敏（包括低血压、皮疹等）。结果两组输液总量无显著性差异。观察组与对照组相比：胶体液用量、晶体液用量、浓缩红细胞用量均有显著性差异,（P〈0．05）。观察组未发现因输注6％羟乙基淀粉130／0．4而出现的不良反应。结论6％羟乙基淀粉130／0．4可安全、有效的用于小儿腹部大手术中的容量治疗。     

Comparison of stroke volume (SV) and stroke volume respiratory variation (SVV) measured by the axillary artery pulse-contour method and by aortic Doppler echocardiography in patients undergoing aortic surgery

Background. The goal of the study was to compare stroke volume(SV) and respiratory stroke volume variation (SVV) measuredby pulse-contour analysis and aortic Doppler. Methods. These were measured by pulse-contour analysis and thermodilution(PiCCO) and by aortic pulsed wave Doppler with transoesophagealechocardiography in patients undergoing abdominal aortic surgery.Simultaneous measurements were done at different times of surgery.All data were recorded on PiCCOwin software and videotape andanalysed off-line by a blinded investigator. Results. A total of 114 measurements were achieved in 20 patients.There was a good correlation and small bias between the PiCCOand the echo-Doppler values of the mean SV [r=0.885; bias=0.2(8) ml], and between the minimum [r=0.842; bias=1 (9) ml] andmaximum SV [r=0.840; bias=2 (10) ml] values. Conclusions. There is a fair correlation between pulse-contouranalysis and aortic Doppler for beat-by-beat measurement ofSV but not for calculation of SV respiratory ventilation.     

A study on postoperative management and pre-and postoperative changes of blood volume in orthopedic surgery (author's transl)

In order to apply adequate postoperative management of patients in the orthopedic surgery, the in vivo effects of the operations were investigated in the present study, from various viewpoints such as circulatory functions, metabolism of proteins, and hepatic and renal functions. In addition, the circulating blood volumes were determined in order to know the variations in the amount of blood loss from the operated regions during and after operations so as to improve the operative and postoperative management. On the basis of the results, the countermeasures against the adverse variations in blood volume were also investigated. Pediatric patients were found to be prone to develop more appreciable systemic postoperative reactions than those in adult ages, especially so in those of circulatory system, peripheral blood, hepatic functions, and protein metabolism, and also prone to be more affected by operative procedures. Senile patients were found to be prone to have less reserve capacity in circulation, peripheral blood, renal functions, and protein metabolism, and also prone to show delayed postoperative reactions and slower recoveries. The results of measurement of circulating blood volume in pre- and postoperations revealed that the loss of circulating blood in most patients was greater than the bleeding weight during the operation measured by gause count, and that, on the day following the operation, the blood volume was reduced by about 10-15% than those immediately after the operation. It was concluded that, as a whole, no changes causing serious deviation from the normal physiological ranges occur except in pediatric and senile patients. On the basis of the above findings, most appreciable systemic postoperative reactions of the operative procedures in orthopedic surgery would be attributed to by loss of blood volume during operations and that the postoperative hemorrhage from bone structure (which is usually difficult to control) or the postoperative hemorrhage after removal of air tourniquet would be almost negligible.     

Haemodynamic changes during induction of anaesthesia with midazolam and diazepam (Valium) in patients undergoing coronary artery bypass surgery

Midazolam 0.3 mg/kg and diazepam 0.5 mg/kg were used for induction of anaesthesia in two groups of 10 patients each undergoing coronary artery bypass surgery. Haemodynamic variables were measured during induction of anaesthesia, after pancuronium and following tracheal intubation. Haemodynamic indices were derived from these measurements using standard formulae. The induction of anaesthesia with midazolam produced a slight but significant increase in heart rate. There was a significant fall in systemic arterial pressure and pulmonary artery pressure following both drugs. Despite the fall in systemic arterial pressure, the cardiac index was maintained in patients who received midazolam. The cardio-stimulatory effect of laryngoscopy and tracheal intubation was not prevented by either of the benzodiazepines and morphine in the dosage used. Midazolam is a suitable alternative to diazepam as part of an intravenous induction regimen in patients with ischaemic heart disease.     

Lung protective ventilation strategy to reduce postoperative pulmonary complications (PPCs) in patients undergoing robot-assisted laparoscopic radical cystectomy for bladder cancer: A randomized double blinded clinical trial

Study objectiveTo evaluate the effects of ventilation with low tidal volume and positive end-expiratory pressure (PEEP) on postoperative pulmonary complications in patients undergoing robot-assisted laparoscopic radical cystectomy (RARC) for bladder cancer.DesignA prospective randomized double-blinded study.SettingA single center trial in a comprehensive tertiary hospital from January 2017 to January 2019.PatientsA total of 258 patients undergoing RARC for bladder cancer.InterventionsPatients were randomly assigned to receive either lung-protective ventilation (LPV group) [tidal volume 6 ml/ kg predicated body weight (PBW) + PEEP 7 cmH₂O] or nonprotective ventilation (control group) (tidal volume 9 ml/ kg PBW without PEEP) during anesthesia.MeasurementsThe primary outcome was the occurrence of postoperative pulmonary complications (PPCs) during the first 90 days after surgery. The secondary outcomes were extubation time, oxygenation index (OI) after extubation and at postoperative day 1 in blood gas.Main resultsThe incidence of PPCs at postoperative day1, 2 and 3 were lower in LPV group [26.8% vs. 47.2%, odds ratio (OR) 0.41, 95% confidence interval (CI), 0.24–0.69, P = 0.0007, 21.3% vs. 43.3%, OR 0.36, 95% CI, 0.20–0.61, P = 0.0002, 14.2% vs. 27.5%, OR0.43, 95%CI, 0.23–0.82, P = 0.0087, respectively], while no differences were observed at day 7 and 28 (3.9% vs. 9.4%, P = 0.0788, 0% vs. 1.6%, P = 0.4980, respectively). No PPCs were observed at postoperative day 90 in both groups. Furthermore, immediately after extubating and at postoperative day 1, OI was significantly higher in LPV group compared with control group [390(337–467) vs. 343(303–420), P = 0.0005, 406.7(73.0) vs. 425.5(74.7), P = 0.0440, respectively]. Patients in LPV group had a significant shorter extubation time after operation compared with control group [38(33–54) vs. 35(25–46), P = 0.0012].ConclusionLPV combining low tidal volume and PEEP during anesthesia for RARC may decrease the incidence of postoperative pulmonary complications.     

Effects of intravascular volume therapy using hydroxyethyl starch (130/0.4) on post-operative bleeding and transfusion requirements in children undergoing cardiac surgery: a randomized clinical trial

BACKGROUND: Hydroxyethyl starch (HES) used for intravascular volume expansion may cause coagulation abnormalities, especially in cardiac patients. Although low molecular weight HES (130/0.4) has been developed to minimize its influence on coagulation, experience with HES (130/0.4) in children is limited. Therefore, we evaluated the effects of a HES (130/0.4) infusion on post-operative blood loss in children undergoing cardiac surgery. METHODS: Forty-two children undergoing cardiac surgery were assigned at random to receive either 10 ml/kg fresh frozen plasma (FFP group; n=21) or HES (130/0.4) (HES group; n=21) shortly after cardiopulmonary bypass termination. Activated partial thromboplastin time (aPTT) and international normalization ratio (INR) were measured. In addition, post-operative transfusion requirements and blood loss until the end of the first post-operative day were compared. RESULTS: INR was significantly prolonged after HES infusion in comparison to the FFP group (P<0.05). During the first 24 h after surgery, post-operative blood loss, the use of allogenic blood/blood products and aPTT were similar in all children. CONCLUSIONS: Our study shows that the administration of a moderate dose of HES (130/0.4) in children undergoing cardiac surgery does not cause more bleeding or a higher transfusion requirement than a FFP infusion, and suggests that the administration of 10 ml/kg HES (130/0.4) is a safe alternative to plasma for intravascular volume replacement in this patient population.