Substance use disorder in the anaesthetist: Guidelines from the Association of Anaesthetists: Guidelines from the Association of Anaesthetists

Anaesthetists have a higher incidence of substance use disorder when compared with other doctors. This might be due to the ease of access to intravenous opioids, propofol, midazolam, inhalational agents and other anaesthetic drugs. Alcohol use disorder continues to be the most common problem. Unfortunately, the first sign that something is amiss might be the anaesthetist's death from an accidental or deliberate overdose. While there are few accurate data, suicide is presumed to be the cause of death in approximately 6-10% of all anaesthetists. If we are to prevent this, substance use disorder must be recognised early, we should ensure the anaesthetist is supported by their department and hospital management and that the anaesthetist engages fully with treatment. Over 75% of anaesthetists return to full practice if they co-operate fully with the required treatment and supervision.

Ultrasound-guided infraclavicular axillary vein cannulation: a useful alternative to the internal jugular vein

BACKGROUND

Ultrasound (US) guidance reduces complications and increases accuracy during internal jugular vein (IJV) cannulation. The subclavian vein (SCV) is popular but is less amenable to US guidance. The axillary vein (AxV), a direct continuation of the SCV, is an alternative, but to date, experience with US is limited to small case series.

METHODS

Retrospective procedural data were collected on 2586 sequential patients referred for insertion of tunnelled central venous access at a UK tertiary centre from 2004 to 2011.

RESULTS

A total of 99.8% of patients tolerated the procedure with local anaesthesia ± sedation; six patients had general anaesthesia. Twenty-six (1%) patients had uncorrected coagulopathy or thrombocytopenia. A total of 2572 (99.5%) of patients were cannulated successfully: right AxV 1644 cases, left AxV 279, right IJV 547, left IJV 89, other techniques 13, and 14 (0.5%) cases failed. The initial site chosen was successful in 96%. In patients who previously underwent long-term cannulation, 93.3% of lines were sited easily. Forty-eight (1.9%) procedural complications occurred.

CONCLUSIONS

In this large analysis of US-guided central venous access in a complex patient group, the majority of patients were cannulated successfully and safely. The subset of patients undergoing AxV cannulation demonstrated a low rate of complications. The AxV route of access appears to be a safe and effective alternative to the IJV.

Role of prophylactic uterine artery balloon catheters in the management of women with suspected placenta accreta

BACKGROUND

Placenta praevia and accreta are leading causes of major obstetric haemorrhage and peripartum hysterectomy. Detection is largely based on a high index of clinical suspicion, though the diagnostic accuracy of radiological imaging is improving. Interventional radiological techniques can reduce blood loss and the incidence of hysterectomy.

METHODS

We have reviewed our experience with bilateral prophylactic uterine artery balloon occlusion in the management of women with suspected placenta accreta. Thirteen women at high risk of major haemorrhage due to placenta praevia or suspected placenta accreta were retrospectively studied. Uterine artery balloons were placed prophylactically under neuraxial anaesthesia in the angiography suite followed by caesarean delivery in the obstetric operating theatre.

RESULTS

Intraoperative blood loss and transfusion requirements were low in our case series. There were no hysterectomies or admissions to the intensive care unit. Fetal bradycardia necessitating immediate caesarean delivery occurred in two women (15.4%).

CONCLUSION

In our case series in women with suspected placenta accreta, prophylactic use of uterine artery balloons was associated with a low requirement for blood transfusion but with possible increased risk of fetal compromise. Performing the interventional procedure at a different site from the operative room complicated management.

A comparison of infero-nasal and infero-temporal sub-Tenon's block

BACKGROUND AND OBJECTIVE

Sub-Tenon's block is usually delivered by the infero-nasal (IN) approach, but occasionally this may not be possible. The infero-temporal (IT) approach has been described, but data is not available on its efficacy.

METHODS

One hundred patients undergoing cataract extraction were randomized to receive an IN or IT sub-Tenon's injection of lidocaine 2% with hyaluronidase 15 IU mL-1. Akinesia was assessed using the Brahma scale at 0, 2, 4, 6 and 8 min. Injection, intraoperative and postoperative pain scores (verbal analogue score, 0-10) were noted, along with the incidence of sub-conjunctival haemorrhage and chemosis.

RESULTS

There were no differences in patient characteristics data, or mean volume of administered local anaesthetic solution (3.3 (SD = 0.4) mL). There were no significant differences between groups in terms of onset of akinesia. Mean akinesia scores at 2, 4, 6 and 8 min were 2.7, 1.1, 0.4 and 0.2 for Group IN, compared to 2.2, 0.9, 0.8 and 0.3 for Group IT. Chemosis occurred in 14 patients in Group IN, compared to 22 in Group IT (P = 0.21).A sub-conjunctival haemorrhage was noted in 14 patients in Group IN and 19 patients in Group IT (P = 0.52). No patients required supplementary injections. Mean pain scores for the injection, intraoperatively and postoperatively were 0.9, 0 and 0 for Group IN, compared to 1.1, 0 and 0 for group IT. The surgeons scored all the blocks as 'good' except for one patient in each group.

CONCLUSIONS

The IT approach provides an equally rapid onset of block, without a significant increase in complications.

A comparison of three sub-Tenon's cannulae

PURPOSE

To compare the quality of anaesthesia and complication rates between three sub-Tenon cannula of increasing length (anterior Greenbaum, mid Kumar-Dodds, and posterior Steven's sub-Tenon's cannulae).

METHODS

A total of 150 patients undergoing cataract extraction were randomised to receive a sub-Tenon injection of 5 ml of 2% lidocaine with hyaluronidase with one of the three cannulae. The development of akinesia was assessed every 2 min over a 6-min period. Complications were also recorded.

RESULTS

There was no difference in the onset of akinesia, with 46, 50, and 46 patients achieving adequate akinesia within 6 min for the anterior, mid, and posterior groups respectively (P>0.05). There was an increase in retained lid opening with anterior compared to mid and posterior cannulae (P=0.0001). There was significantly less retained lid closure with the posterior compared to the mid or anterior cannulae (P<00001). The mean (range, SD) scores for pain during injection were 0.4 (0-5, 0.83), 1.2 (0-9, 1.96), and 1.1 (0-6, 1.19) for the anterior, mid, and posterior groups, respectively. These were not significantly different between the anterior and mid groups, or the mid and posterior groups (P>0.05), but there was significantly more pain on injection with the posterior compared to the anterior groups (P<0.01). All patients scored intraoperative pain as zero. There was significantly more chemosis in the anterior group (76%) compared to the mid (20%) and posterior (32%) groups (P<0.0001). There were significantly (P=0.0004) more conjunctival haemorrhages in the anterior group (56%) than the mid (20%) or posterior (20%) groups.

CONCLUSIONS

We have shown that all three cannulae provide high-quality anaesthesia with minor differences in retained muscle activity, chemosis, and haemorrhage rates.

Fast scan magnetic resonance imaging and Doppler ultrasonography of uteroplacental hemodynamics in the rhesus monkey (Macaca mulatta)

Fast scan magnetic resonance imaging, color Doppler ultrasonography, and magnetic resonance angiography were used to demonstrate the uteroplacental hemodynamics in rhesus monkeys. "Jets" of maternal blood spurting into the placenta were observed with, or without, the use of a contrast medium from 114 days to the term of pregnancy. Cumulative intravenous doses of cocaine hydrochloride brought about changes in the sequences of imaging of the maternal blood inflow to the placenta. These methods appear suitable for non-invasive monitoring of the effects of drugs on placental function.