RETROSPECTIVE ANALYSIS OF SPINAL ANESTHESIA FOR DAYCARE SURGERY DURING THE COVID-19 PANDEMIC.

general


INTRODUCTION
The years a er 2020 have been challenging for all health care professionals due to the COVID-19 pandemic.Anaesthesiologist are at higher risk of exposure to COVID virus because airway interven ons, like a bag and mask ven la on, use of supraglo c airway devices, intuba on and extuba on of trachea generate aerosol.The Odds of transmission of acute respiratory infec on during tracheal intuba on to a healthcare professional is 6.6 mes higher 1 than those not exposed to tracheal intuba on.Avoiding airway manipula ons and aerosol genera ng procedures may reduce 2 the risk of COVID-19 transmission to healthcare workers.When pa ent is discharged from the hospital on the same day a er any surgical procedures is known as daycare surgery.Post Anesthesia Discharge scoring System (PADSS) is a well-accepted tool used to discharge pa ents who are 3 posted for daycare surgery.The poten al benefits of daycare surgeries for the pa ents are more personalized care, high sa sfac on, and recovery in a home environment, similarly, the benefits for the hospitals are high turnover, running cost reduc on, fewer requirements of manpower, 4 etc.The daycare surgeries are performed under seda on or general anesthesia.Recovery of the motor blockade a er use of bupivacaine in spinal anesthesia takes a longer dura on.Spinal anesthesia prolongs me to achieve PADSS.Before the COVID-19 pandemic, we preferred general anesthesia to spinal anesthesia for daycare surgeries in our center.During the COVID-19 pandemic started, we started offering spinal anesthesia wherever spinal anesthesia would be applicable, to our pa ents as an op on over 3,4,6 general anesthesia for daycare procedures.We intended to compare me taken to discharge pa ent a er a subarachnoid block with general anesthesia in daycare surgery pa ents in this review.We also planned to compare me to achieve a score equal to or more than nine using PADSS, the need for overnight hospitaliza on, and complica ons between spinal and general anesthesia.

METHODOLOGY Pa ents
A er IRC clearance (ref number: IRC-RP-2077/004), all cases posted for elec ve daycare surgery in our ins tute from the start of COVID-19 pandemic from May 2020 to November 2020 were included in this study.

Exclusion criteria
Surgery done under local anesthesia, MAC, Peripheral nerve block, and any admi ed cases due to surgical complica on, ASA-PS IV and V were excluded from this study.

Anesthe c Technique
All the pa ents who were posted for daycare surgery were given the choice of anesthesia either of general anesthesia or spinal anesthesia was given.Risks and benefits of either technique and the risk associated COVID-19 were well explained.Pa ents and their rela ves decided the mode of anesthesia.
Pa ents were requested to have nil per oral of 6 hours for solid food and 2 hours for clear liquid and it was confirmed on day of surgery.No premedica ons were allowed, except for chronic medica ons.An intravenous line with 18G or 20G needle was secured and the ringer's lactate solu on was started.ECG and oxygen satura on (SPO2) was monitored con nuously and automated noninvasive blood pressure was measured every 5 minutes throughout the surgery in all the cases.Standard techniques of subarachnoid block or general anesthesia were administered according to ins tu onal protocol.Spinal anesthesia was administered with the pa ent in either lateral decubitus or si ng posi on at L2-3 or L3-4 interspace a er infiltra on with local anesthe c.A 27-gauge spinal needle (Whitacre) was used and hyperbaric bupivacaine 5-10 mg was injected a er free flow of CSF.If there were difficul es performing subarachnoid block with a 27 gauze needle, anesthesiologists used a 25 gauze Quincke needle.If supplemental general anesthesia was required due to complete or par al failure of spinal anesthesia, the pa ents were analyzed as the general anesthesia group.General anesthesia was induced with propofol 1.5 mg/kg 1 and fentanyl.microgram/kg.The supplement oxygen was given via simple face mask.If oxygena on was adequate with the facemask, the airways was secured with I-gel R (intersurgical ).If anesthesiologists preferred endotracheal intuba on, then vecuronium 0.1mg/kg was given and reversal of neuromuscular blockade was done with neos gmine and glycopyrrolate in such cases.All the pa ents received 1mg injec on granisetron at the end of surgery.Pa ents were then transferred to the postanesthesia care unit, where vitals (pulse rate, blood pressure, SPO2 and respiratory rate) were monitored as per ins tute standard protocol and charted in the modified early warning system (MEWS) chart.In addi on to MEWS, PADSS and Aldrete's scores were also monitored every 30 minutes ll a score of 9 or more was achieved.If the PADSS more than 9 was not achieved within 24 hours, pa ents would be considered as admission.Pa ents were allowed out of bed mobiliza on as soon as the spinal block had regressed and the pa ents felt comfortable.

Evalua on of outcomes
The me to discharge, me to achieve score equal to or more than nine using PADSS; need for overnight hospitaliza on; and side effects and complica ons like hypotension, bradycardia /tachycardia, nausea, vomi ng, urinary reten on, fall, shivering, headache and backache were recorded from the charts and postopera ve telephonic surveys.

Post-opera ve follow-up
Incidence of post-discharge headache and other associated complica ons were extracted from post-discharge telephone survey records.

Policy for missing and conflic ng data:
If data on discharge mes and score of PADSS swere unavailable, such cases were excluded from analysis.If data on more than 10% of the variables were unavailable, such cases were also excluded from analysis.A conflic ng data is defined as two or more different versions of the same event in the database.In case of conflic ng data the first recorded data were accepted.

Sta s cal analysis:
The abstractor, who is not involved in the study, reviewed the medical data record and entered the data in the Excel chart according to inclusion criteria.Normality of distribu on of data was determined using Two sample Kolmogorov-Smirnov Test and review of histograms.Student t test was used for normally distributed data whereas Mann-Whitney U test was used for non-normal distributed data (mean me to discharge and the mean me to achieve score of 9 PADSS.Categorical variables were analyzed using a chi-squared or Fisher's exact test.A p-value < 0.05 was considered sta s cally significant.Post-hoc power calculator clinical was used to determine the power 13 of the study.

RESULT
Out of two thousand two hundred and fourteen surgeries performed from May to November 2020, one hundred and eighty two cases were posted as daycare surgery.Among these, twenty cases met exclusion criteria and hence excluded from the analysis (Figure1).Those who met inclusion criteria, seventy-one cases were done under general anesthesia and ninety-one cases were performed under spinal anesthesia.One case where data could not be retrieved was excluded from the analysis.(Figure 1).There was not any conflic ng data.Demographic descrip on and type of anesthesia delivered for daycare surgery are shown in Table 1.The post hoc power of the study was 95.8.Complica ons were not recorded in both groups.Onepa ents required admissions due to fall however no other significant complica ons associated spinal and general anesthesia were recorded during hospital stay.The telephonic survey did not record any incidence of postdural puncture headache hypotension (PDPH), bradycardia /tachycardia, nausea, vomi ng, urinary reten on, fall, shivering, headache and backache within one month follow-up records of the pa ents.

DISCUSSION
In our study, we found that out of seventy cases done under general anesthesia (GA) and ninety-one cases performed under spinal anesthesia (SAB) the mean me to achieve 9 score using PADSS in group GA is four hours and twenty-four minutes (4 hours 24 mins) whereas in group SAB was five hours and thirty-nine minutes (5 hours 39 mins).Similarly, the mean me taken to discharge home in group GA was four hours fi y-five minutes whereas in group SAB was six hours and five minutes respec vely.The post hoc power of the study was 95.8.Besides, one pa ent in group SAB needs hospital admission, no other complica ons are recorded during the periopera ve period and forty-eight-hour and one-month telephonic follow-up.The mean me difference to achieve 9 score using PADSS and me to discharge was sta s cally significant but the difference between one hour and fi een minutes and two hours and ten minutes Bha arai PR et al respec vely are not prac cally significant.There were no significant complica ons during hospital stay and follow up a er one month.The dose of bupivacaine as low as 5-10 mg was sufficient to elicit the adequate anesthesia for different types of surgery 8,9 like gynecological laparoscopic, lower limb surgeries.In a study done by Gupta et al in 2011 where PADSS score a er spinal anesthesia was noted and pa ents were discharged only when they achieved a total score of 9. Thirty-two 32 pa ents (62%) achieved discharge criteria within 4-8 hours while 28% of pa ents achieved discharge criteria within 8-10 12 hours.The results were similar to our study where we used comparable dose of bupivacaine and achieved discharge criteria within 6-7 hours.Our study finding of 365.66 minutes in the SAB group was similar to the study done by Sirivanasandha B where the mean me to discharge was 309+/-94 minutes where low dose 11 bupivacaine was used for the TURP procedure.The me required to achieve the PADS score a er different doses of bupivacaine was out of scope of the study design.12 A study by Kallio et al showed that pa ents were fit for discharge a er 6.0 hours (5.2-6.6hours) and were discharged a er 6.6 hours (5.9-9.0 hours) a er 10mg of plain ropivacaine with spinal anesthesia.In our study, the me dura on for the discharge of pa ents from PACU was 296.08 minutes (4.93 hours) among the general anesthesia group whereas it was 365.66 minutes (6.09 hours) among the spinal group.In the SAB group, the me to discharge was almost similar to the study by Kallio, though they had used ropivacaine.The recovery me of motor blockade by ropivacaine a er spinal anesthesia is faster than the same by bupivacaine.In our study, all pa ents did not received the same dose of bupivacaine as we had used the lowest possible dose.The dura on of motor blockade by different doses of bupivacaine a er spinal anesthesia for daycare surgery could not be analyzed in the present study.Bri sh Associa on of Day Surgery suggested that spinal anesthesia is well accepted for use in day surgery with the introduc on of low-dose local anesthe cs and newer shorter-ac ng local anesthe cs such as hyperbaric prilocaine 2% and 2-chloroprocaine.However, we use 0.5% heavy Bupivacaine less than 10 mg that we found very 6 effec ve with minimal adverse effects.In our study, we did not record any major complica ons.None of our pa ents required Foley catheteriza on or re-admission due to urinary reten on.There were no incidence of postopera ve nausea and vomi ng, postopera ve confusion.There was no incidence of PDPH in our study as telephonic follow-up was done 48 hours and one month following pa ent discharge.There were many reasons for the lesser incidence of postopera ve complica ons.First we used the lower dose of bupivacaine i.e. less 10 mg.The lower dose of bupivacaine a ributed not only to the faster motor recovery but also to the minimal complica ons.Second we used small bore i.e. 27 gauze pencil-pointed spinal needles and third according to our intui onal protocol, we performed all spinal anesthesia in the lateral decubitus posi on using a twenty-seven gauge pencil point spinal needle.In case of difficulty with spinal anesthesia, we used a twenty-five gauge Quincke-type spinal needle but we maintained the decubitus posi on.The pencil point (Whitacre needle) twenty-seven gauge was used for spinal anesthesia which may be a ributed to a 13 lower incidence of PDPH.Concerns regarding post-dural puncture headache have previously limited the use of spinal anesthesia in day surgery pa ents, but the use of smaller gauge (27 G) and pencil-point needles has reduced the 3,13 incidence of PDPH to <1% as.Furthermore, we performed spinal anesthesia in the lateral decubitus posi on which may have a ributed lower incidence of PDPH.Though not the scope of the present study, the incidence of PDPH is 13 lower if spinal anesthesia is performed in a lateral posi on.One pa ent in the group SAB group was admi ed for a fall a er mobiliza on which may be a ributed to the finding of postural hypotension.Old age, low albumin level, prolonged dura on of surgical me, incomplete recovery of motor power a er spinal anesthesia, and residual effects of anesthe cs are the causes of falls in the postopera ve period.Interes ngly, the most incidence of falls during postanesthesia care occur in day me, bedside, and wards but not in cri cal areas.It may be because pa ents and their 14 caretakers became less cau ous in these situa ons.We used the PADSStool to mobilize the pa ent.Pa ents were mobilized only a er the complete reversal of motor power.

CONCLUSION
With low-dose bupivacaine, spinal anesthesia is an effec ve for ambulatory daycare surgeries with early mobiliza on and no incidence of adverse events such as urinary reten on, PDPH, and PONV.Thus during this pandemic of COVID-19, we foundspinal anesthesia performed with hyperbaric bupivacaine (5-10mg) is an safe alterna ve to GA.

RECOMMENDATIONS
We recommend spinal anesthesia could be used for daycare surgeries and the discharge scoring tools like PADSS should to be implied to discharge pa ents who are posted for daycare surgeries.

LIMITATION OF THE STUDY
As with other retrospec ve studies, selec on bias is a limita on of our study.A rela vely small sample size also is another limita on.If the study included preopera ve and postopera ve data on SARS-CoV-2 rT-PCR data and clinical symptoms, the study would have been more meaningful.

CONFLICT OF INTEREST
Authors have no conflict of interest and financial considera ons

Figure 1 :
Figure 1: Consort flow diagram spinal vs general anesthesia for daycare surgery.

Table 2 :
Comparison of me taken to achieve 9 score using PADSS and me taken to discharge.

Table 1 :
Comparison of Demographic distribu on.*Dataaregiven in mean (+SD) #Data is given in absolute numbers.The mean me to achieve 9 score using PADSS for groups GA vs SAB was 263.47 minutes (i.e.four hour and twenty-four minutes) vs 339.55 minutes (i.e.five hours and thirty-nine minutes).Similarly, the mean me taken to discharge home and 296.08 minutes (four hours fi y-five minutes) vs 347.29 minutes (i.e. six hours and five minutes) respec vely, and shown in Table2.
* me expressed in minutes.PADSS: Post Anesthesia Discharge Scoring System *Data are given in mean (+SD)