Effect of high-flow nasal oxygen on hypoxaemia during procedural sedation: a systematic review and meta-analysis.

We conducted a systematic review to evaluate the effect of high-flow nasal oxygen and conventional oxygen therapy during procedural sedation amongst adults and children. We searched MEDLINE, EMBASE and CINAHL for randomised controlled trials that reported the effects of high-flow nasal oxygen during procedural sedation. The primary outcome measure was hypoxaemia and the secondary outcomes were minimum oxygen saturation; hypercarbia; requirement for airway manoeuvres; and procedure interruptions. The quality of evidence was assessed using the revised Cochrane risk-of bias tool and grading of recommendations, assessment, development and evaluation (GRADE). Nineteen randomised controlled trials (4121 patients) including three in children were included. Administration of high-flow nasal oxygen reduced hypoxaemia, risk ratio (95%CI) 0.37 (0.24-0.56), p < 0.001; minor airway manoeuvre requirements, risk ratio (95%CI) 0.26 (0.11-0.59), p < 0.001; procedural interruptions, risk ratio (95%CI) 0.17 (0.05-0.53), p = 0.002; and increased minimum oxygen saturation, mean difference (95%CI) 4.1 (2.70-5.50), p < 0.001; as compared with the control group. High-flow nasal oxygen had no impact on hypercarbia, risk ratio (95%CI) 1.24 (0.97-1.58), p = 0.09, I2 = 0%. High-flow nasal oxygen reduced the incidence of hypoxaemia regardless of the procedure involved, degree of fractional inspired oxygen, risk-profile of patients and mode of propofol administration. The evidence was ascertained as moderate for all outcomes except for procedure interruptions. In summary, high-flow nasal oxygen compared with conventional oxygenation techniques reduced the risk of hypoxaemia, increased minimum oxygen saturation and reduced the requirement for airway manoeuvres. High-flow nasal oxygen should be considered in patients at risk of hypoxaemia during procedural sedation.

Effect of high-flow vs. low-flow nasal plus mouthguard oxygen therapy on hypoxaemia during sedation: a multicentre randomised controlled trial.

Whether high-flow vs. low-flow nasal oxygen reduces hypoxaemia for sedation during endoscopic retrograde cholangiopancreatography is currently unknown. In this multicentre trial, 132 patients ASA physical status 3 or higher, BMI > 30 kg.m-2 or with known or suspected obstructive sleep apnoea were randomly allocated to high-flow nasal oxygen up to 60 l.min-1 at 100% FI O2 or low-flow nasal oxygen at 4 l.min-1 . The low-flow nasal oxygen group also received oxygen at 4 l.min-1 through an oxygenating mouthguard, totalling 8 l.min-1 . Primary outcome was hypoxaemia, defined as Sp O2 < 90% regardless of duration. Hypoxaemia occurred in 7.7% (5/65) of patients with high-flow and 9.1% (6/66) with low-flow nasal oxygen (percentage point difference -1.4%, 95%CI -10.9 to 8.0; p = 0.77). Between the groups, there were no significant differences in frequency of hypoxaemic episodes; lowest Sp O2 ; peak transcutaneous carbon dioxide; hypercarbia (transcutaneous carbon dioxide > 2.66 kPa from baseline); requirement of chin lift/jaw thrust; nasopharyngeal airway insertion; bag-mask ventilation; or tracheal intubation. Following adjustment for duration of the procedure, the primary outcome remained non-significant. In high-risk patients undergoing endoscopic retrograde cholangiopancreatography, oxygen therapy with high-flow nasal oxygen did not reduce the rate of hypoxaemia, hypercarbia or the need for airway interventions, compared with combined oral and nasal low-flow oxygen.

A comparison of ultrasound guided bilateral single injection shot Erector Spinae Plane blocks versus wound infiltration for post-operative analgesia in laparoscopic assisted colonic surgery- a prospective randomised study.

BACKGROUND: Both wound infiltration (WI) with local anaesthetic and Erector Spinae Plane block (ESPB) have been described for post-operative analgesia after abdominal surgery. This study compared the efficacy of WI versus ESPB for post-operative analgesia after laparoscopic assisted colonic surgery. METHODS: Seventy-two patients between 18 and 85 years of age undergoing elective surgery were randomised to receive either WI or ESPB. In the WI group a 40 ml bolus of 0.5% Ropivacaine, infiltrated at the ports and minimally invasive wound at subcutaneous and fascia layers. In the ESPB group at T8 level, under ultrasound guidance, a 22-gauge nerve block needle was passed through the Erector Spinae muscle to reach its fascia. A dose up to 40 ml of 0.5% Ropivacaine, divided into two equal volumes, was injected at each side. Both groups had a multimodal analgesic regime, including regular Paracetamol, dexamethasone and patient-controlled analgesia (PCA) with Fentanyl. The primary end point was a post-operative pain score utilising a verbal Numerical Rating Score (NRS, 0-10) on rest and coughing in the post anaesthetic care unit (PACU) and in the first 24 h. Secondary outcomes measured were: opioid usage, length of stay and any clinical adverse events. RESULTS: There was no significant treatment difference in PACU NRS at rest and coughing (p-values 0. 382 and 0.595respectively). Similarly, there were no significant differences in first 24 h NRS at rest and coughing (p-values 0.285 and 0.431 respectively). There was no significant difference in Fentanyl use in PACU or in the first 24 h (p- values 0.900 and 0.783 respectively). Neither was there a significant difference found in mean total Fentanyl use between ESPB and WI groups (p-value 0.787). CONCLUSION: Our observations found both interventions had an overall similar efficacy. TRIAL REGISTRATION: The study was registered with the Australian New Zealand Clinical Trial Registry (ACTRN: 12619000113156 ).

Comparison of ultrasound-guided transmuscular quadratus lumborum block catheter technique with surgical pre-peritoneal catheter for postoperative analgesia in abdominal surgery: a randomised controlled trial.

Following abdominal surgery, the provision of postoperative analgesia with local anaesthetic infusion through both transmuscular quadratus lumborum block and pre-peritoneal catheter have been described. This study compared these two methods of postoperative analgesia following laparotomy. Eighty-two patients 18-85 years of age scheduled to undergo elective surgery were randomly allocated to receive either transmuscular quadratus lumborum block or pre-peritoneal catheter block. In the transmuscular quadratus lumborum group, an 18-gauge Tuohy needle was passed through the quadratus lumborum muscle under ultrasound guidance to reach its anterior aspect. A 20-ml bolus of ropivacaine 0.375% was administered and catheters placed bilaterally. In the pre-peritoneal catheter group, 20 ml of ropivacaine 0.375% was infiltrated at each of three subcutaneous sub-fascial levels, and pre-peritoneal plane catheters were placed bilaterally. Both groups received an infusion of ropivacaine 0.2% at 5 ml.h-1 , continued up to 48 h along with a multimodal analgesic regime that included regular paracetamol and patient-controlled analgesia with fentanyl. The primary end-point was postoperative pain score on coughing, assessed using a numerical rating score (0-10). Secondary outcomes were pain score at rest, fentanyl usage until 48 h post-operation, satisfaction scores and costs. There was no treatment difference between the two groups for pain score on coughing (p = 0.24). In the transmuscular quadratus lumborum group, there was a reduction in numerical rating score at rest (p = 0.036) and satisfaction scores on days 1 and 30 (p = 0.004, p = 0.006, respectively), but fentanyl usage was similar. In the transmuscular quadratus lumborum group, the highest and lowest blocks observed in the recovery area were T4 and L1, respectively. The transmuscular quadratus lumborum technique cost 574.64 Australian dollars more per patient than the pre-peritoneal catheter technique.

The effect of sevoflurane on the transmural dispersion of repolarisation in patients with type 2 diabetes mellitus: a prospective observational study.

The 'torsadogenic' property of a drug is linked to its ability to increase the transmural dispersion of repolarisation, represented by the interval between the peak of, and the end of, the T-wave (Tp-e interval) in an electrocardiogram. Reports have consistently shown that sevoflurane does not increase the Tp-e interval. Type 2 diabetes is a risk factor for increased QTc (rate-corrected QT interval), QTcd (rate-corrected QTc dispersion: difference between the maximum and the minimum QTc interval), and Tp-e, as well as the rate-corrected Tp-e (Tp-e/QTc ratio). The study aimed to ascertain whether sevoflurane increased the Tp-e interval and Tp-e/QTc ratio in patients with diabetes, thereby increasing their risk of torsades. We enrolled 35 female patients; 17 with type 2 diabetes and 18 controls undergoing non-laparoscopic surgery under sevoflurane anaesthesia. The Tp-e interval, Tp-e/QTc ratio, QTc and QTcd were recorded after intubation, 5, 10, 30 and 60 minutes into the anaesthetic, and were compared between the groups. No significant increase in the Tp-e interval or Tp-e/QTc was observed between or within the groups (a 13 ms increase was considered significant). In the control group, the QTc was significantly increased from baseline immediately after intubation (449 versus 414 ms, P <0.001); at 5 minutes (434 versus 414 ms, P=0.01); at 10 minutes (444 versus 414 ms, P=0.002); at 30 minutes (439 versus 414 ms, P=0.001) and at 60 minutes (442 versus 414 ms; P <0.001) (a 20 ms increase was considered significant). No significant increase in QTc was observed in the diabetic group. There were no between or within group differences observed for QTcd. Our findings suggest that sevoflurane does not have a significant predictable pro-arrhythmic effect in type 2 diabetic patients in the absence of other factors affecting ventricular repolarisation.

Cranial nerve injuries with supraglottic airway devices: a systematic review of published case reports and series.

Cranial nerve injuries are unusual complications of supraglottic airway use. Branches of the trigeminal, glossopharyngeal, vagus and the hypoglossal nerve may all be injured. We performed a systematic review of published case reports and case series of cranial nerve injury from the use of supraglottic airway devices. Lingual nerve injury was the most commonly reported (22 patients), followed by recurrent laryngeal (17 patients), hypoglossal (11 patients), glossopharyngeal (three patients), inferior alveolar (two patients) and infra-orbital (one patient). Injury is generally thought to result from pressure neuropraxia. Contributing factors may include: an inappropriate size or misplacement of the device; patient position; overinflation of the device cuff; and poor technique. Injuries other than to the recurrent laryngeal nerve are usually mild and self-limiting. Understanding the diverse presentation of cranial nerve injuries helps to distinguish them from other complications and assists in their management.

Intraoperative hypothermia is associated with an increased intensive care unit length-of-stay in patients undergoing elective open abdominal aortic aneurysm surgery: a retrospective cohort study.

Intraoperative hypothermia in open elective abdominal aortic aneurysm repair may be associated with increased hospital morbidity. This retrospective, single centre study investigated whether there was an association between intraoperative hypothermia in open elective abdominal aortic aneurysm repair and postoperative in-hospital morbidity. The data of 119 patients who underwent open infrarenal abdominal aortic aneurysm repair between January 2006 and January 2011 were collected. The electronic databases from the hospital, intensive care unit, transfusion medicine and operating theatres were linked by the patient's unique identifiers including date of birth and unit record number. Intraoperative nasopharyngeal temperature measurements were collected manually from paper-based anaesthetic records. The study group included 102 out of the 119 patients. Sixty-six patients (64.6%) had intraoperative hypothermia as defined by temperature <36°C. Intraoperative temperature was not predictive of hospital length-of-stay or any of the other perioperative complications such as acute renal failure, acute respiratory complications, acute myocardial infarction, transfusion requirements or postoperative infection. In the normothermic group, the number of hours in the intensive care unit was 35% lower (ratio of means=0.65; 95% confidence interval 0.51 to 0.84; P=0.0008), even after adjusting for possible confounders such as age, duration of anaesthesia, size of aneurysm, comorbidities and transfusion. Intraoperative hypothermia is a persisting problem and more aggressive warming strategies may need to be identified and employed to achieve normothermia.

Torsade de pointes in a patient with acute prolonged QT syndrome and poorly controlled diabetes during sevoflurane anaesthesia.

We report a case of torsade de pointes secondary to acute QT interval prolongation in a patient with poorly controlled diabetes mellitus towards the end of a laparoscopic nephrectomy under sevoflurane anaesthesia. The patient was successfully resuscitated and made a complete recovery. Our case suggests that acute QT interval prolongation should be considered in any patient with poor glycaemic control during prolonged procedures.